Solar System Portrait - View of the Sun, Earth and Venus

NASA Image and Video Library

1996-09-13

This color image of the sun, Earth and Venus was taken by the Voyager 1 spacecraft Feb. 14, 1990, when it was approximately 32 degrees above the plane of the ecliptic and at a slant-range distance of approximately 4 billion miles. It is the first -- and may be the only -- time that we will ever see our solar system from such a vantage point. The image is a portion of a wide-angle image containing the sun and the region of space where the Earth and Venus were at the time with two narrow-angle pictures centered on each planet. The wide-angle was taken with the camera's darkest filter (a methane absorption band), and the shortest possible exposure (5 thousandths of a second) to avoid saturating the camera's vidicon tube with scattered sunlight. The sun is not large in the sky as seen from Voyager's perspective at the edge of the solar system but is still eight million times brighter than the brightest star in Earth's sky, Sirius. The image of the sun you see is far larger than the actual dimension of the solar disk. The result of the brightness is a bright burned out image with multiple reflections from the optics in the camera. The "rays" around the sun are a diffraction pattern of the calibration lamp which is mounted in front of the wide angle lens. The two narrow-angle frames containing the images of the Earth and Venus have been digitally mosaiced into the wide-angle image at the appropriate scale. These images were taken through three color filters and recombined to produce a color image. The violet, green and blue filters were used; exposure times were, for the Earth image, 0.72, 0.48 and 0.72 seconds, and for the Venus frame, 0.36, 0.24 and 0.36, respectively. Although the planetary pictures were taken with the narrow-angle camera (1500 mm focal length) and were not pointed directly at the sun, they show the effects of the glare from the nearby sun, in the form of long linear streaks resulting from the scattering of sunlight off parts of the camera and its sun shade. From Voyager's great distance both Earth and Venus are mere points of light, less than the size of a picture element even in the narrow-angle camera. Earth was a crescent only 0.12 pixel in size. Coincidentally, Earth lies right in the center of one of the scattered light rays resulting from taking the image so close to the sun. Detailed analysis also suggests that Voyager detected the moon as well, but it is too faint to be seen without special processing. Venus was only 0.11 pixel in diameter. The faint colored structure in both planetary frames results from sunlight scattered in the optics. http://photojournal.jpl.nasa.gov/catalog/PIA00450

Solar System Portrait - View of the Sun, Earth and Venus

NASA Technical Reports Server (NTRS)

1990-01-01

This color image of the sun, Earth and Venus was taken by the Voyager 1 spacecraft Feb. 14, 1990, when it was approximately 32 degrees above the plane of the ecliptic and at a slant-range distance of approximately 4 billion miles. It is the first -- and may be the only -- time that we will ever see our solar system from such a vantage point. The image is a portion of a wide-angle image containing the sun and the region of space where the Earth and Venus were at the time with two narrow-angle pictures centered on each planet. The wide-angle was taken with the camera's darkest filter (a methane absorption band), and the shortest possible exposure (5 thousandths of a second) to avoid saturating the camera's vidicon tube with scattered sunlight. The sun is not large in the sky as seen from Voyager's perspective at the edge of the solar system but is still eight million times brighter than the brightest star in Earth's sky, Sirius. The image of the sun you see is far larger than the actual dimension of the solar disk. The result of the brightness is a bright burned out image with multiple reflections from the optics in the camera. The 'rays' around the sun are a diffraction pattern of the calibration lamp which is mounted in front of the wide angle lens. The two narrow-angle frames containing the images of the Earth and Venus have been digitally mosaiced into the wide-angle image at the appropriate scale. These images were taken through three color filters and recombined to produce a color image. The violet, green and blue filters were used; exposure times were, for the Earth image, 0.72, 0.48 and 0.72 seconds, and for the Venus frame, 0.36, 0.24 and 0.36, respectively. Although the planetary pictures were taken with the narrow-angle camera (1500 mm focal length) and were not pointed directly at the sun, they show the effects of the glare from the nearby sun, in the form of long linear streaks resulting from the scattering of sunlight off parts of the camera and its sun shade. From Voyager's great distance both Earth and Venus are mere points of light, less than the size of a picture element even in the narrow-angle camera. Earth was a crescent only 0.12 pixel in size. Coincidentally, Earth lies right in the center of one of the scattered light rays resulting from taking the image so close to the sun. Detailed analysis also suggests that Voyager detected the moon as well, but it is too faint to be seen without special processing. Venus was only 0.11 pixel in diameter. The faint colored structure in both planetary frames results from sunlight scattered in the optics.

Observed correlation of Venus topography with the zonal wind and albedo at cloud top level: the role of stationary gravity waves.

NASA Astrophysics Data System (ADS)

Bertaux, Jean-Loup; Khatunstsev, Igor; Hauchecorne, Alain; Markiewicz, Wojtek; Emmanuel, Marcq; Sébastien, Lebonnois; Marina, Patsaeva; Alex, Turin; Anna, Fedorova

2016-04-01

Based on the analysis of UV images (at 365 nm) of Venus cloud top (altitude 67±2 km) collected with VMC (Venus Monitoring Camera) on board Venus Express (VEX), it is found that the zonal wind speed south of the equator (from 5°S to 15°s) shows a conspicuous variation (from -101 to -83 m/s) with geographic longitude of Venus, correlated with the underlying relief of Aphrodite Terra. We interpret this pattern as the result of stationary gravity waves produced at ground level by the up lift of air when the horizontal wind encounters a mountain slope. These waves can propagate up to cloud top level, break there and transfer their momentum to the zonal flow. Such upward propagation of gravity waves and influence on the wind speed vertical profile was shown to play an important role in the middle atmosphere of the Earth by Lindzen [1981], but is not reproduced in a current GCM of Venus atmosphere. Consistent with present findings, the two VEGA mission balloons experienced a small, but significant, difference of westward velocity, at their 53 km floating altitude. The albedo at 365 nm varies also with longitude and latitude in a pattern strikingly similar in the low latitude regions to a recent map of cloud top H2O [Fedorova et al., 2015], in which a lower UV albedo is correlated with increased H2O. We argue that H2O enhancement is the sign of upwelling, suggesting that the UV absorber is also brought to cloud top by upwelling.

Imaging of Mercury and Venus from a flyby

USGS Publications Warehouse

Murray, B.C.; Belton, M.J.S.; Danielson, G. Edward; Davies, M.E.; Kuiper, G.P.; O'Leary, B. T.; Suomi, V.E.; Trask, N.J.

1971-01-01

This paper describes the results of study of an imaging experiment planned for the 1973 Mariner Venus/Mercury flyby mission. Scientific objectives, mission constraints, analysis of alternative systems, and the rationale for final choice are presented. Severe financial constraints ruled out the best technical alternative for flyby imaging, a film/readout system, or even significant re-design of previous Mariner vidicon camera/tape recorder systems. The final selection was a vidicon camera quite similar to that used for Mariner Mars 1971, but with the capability of real time transmission during the Venus and Mercury flybys. Real time data return became possible through dramatic increase in the communications bandwidth at only modest sacrifice in the quality of the returned pictures. Two identical long focal length cameras (1500 mm) were selected and it will be possible to return several thousand pictures from both planets at resolutions ranging from equivalent to Earthbased to tenths of a kilometer at encounter. Systematic high resolution ultraviolet photography of Venus is planned after encounter in an attempt to understand the nature of the mysterious ultraviolet markings and their apparent 4- to 5-day rotation period. Full disk coverage in mosaics will produce pictures of both planets similar in quality to Earthbased telescopic pictures of the Moon. The increase of resolution, more than three orders of magnitude, will yield an exciting first look at two planets whose closeup appearance is unknown. ?? 1971.

Observed longitude variations of zonal wind, UV albedo and H2O at Venus cloud top level: the role of stationary gravity waves generated by Venus topography

NASA Astrophysics Data System (ADS)

Bertaux, Jean-Loup; Hauchecorne, Alain; khatuntsev, Igor; Markiewicz, Wojciech; Marcq, emmanuel; Lebonnois, Sebastien; Patsaeva, Marina; Turin, Alexander; Fedorova, Anna

2016-10-01

Based on the analysis of UV images (at 365 nm) of Venus cloud top (altitude 67±2 km) collected with VMC (Venus Monitoring Camera) on board Venus Express (VEX), it is found that the zonal wind speed south of the equator (from 5°S to 15°S) shows a conspicuous variation (from -101 to -83 m/s) with geographic longitude of Venus, correlated with the underlying relief of Aphrodite Terra. We interpret this pattern as the result of stationary gravity waves produced at ground level by the up lift of air when the horizontal wind encounters a mountain slope. These waves can propagate up to the cloud top level, break there and transfer their momentum to the zonal flow. Such upward propagation of gravity waves and influence on the wind speed vertical profile was shown to play an important role in the middle atmosphere of the Earth but is not reproduced in the current GCM of Venus atmosphere from LMD.In the equatorial regions, the UV albedo of clouds at 365 nm and the H2O mixing ratio at cloud top varies also with longitude, with an anti-correlation: the more H2O, the darker are the clouds. We argue that these variations may be simply explained by the divergence of the horizontal wind field. In the longitude region (from 60° to -10°) where the horizontal wind speed is increasing in magnitude (stretch), it triggers air upwelling which brings both the UV absorber and H2O at cloud top level and decreases the albedo, and vice-versa when the wind is decreasing in magnitude (compression). This picture is fully consistent with the classical view of Venus meridional circulation, with upwelling at equator revealed by horizontal air motions away from equator: the longitude effect is only an additional but important modulation of this effect. We argue that H2O enhancement is the sign of upwelling because the H2O mixing ratio decreases with altitude, comforting the view that the UV absorber is also brought to cloud top by upwelling.

Dependence of wind speed and UV albedo at Venus top cloud layer on topography and local time revealed from VMC images

NASA Astrophysics Data System (ADS)

Patsaeva, Marina; Khatuntsev, Igor; Turin, Alexander; Zasova, Ludmila; Bertaux, Jean-loup

2017-04-01

A set of UV (365 nm) and IR (965 nm) images obtained by the Venus Monitoring Camera (VMC) was used to study the circulation of the mesosphere at two altitude levels. Displacement vectors were obtained by wind tracking in automated mode for observation period from 2006 to 2014 for UV images [1,2] and from 2006 to 2012 for IR images. The long observation period and good longitude-latitude coverage by single measurements allowed us to focus on the study of the slow-periodic component. The influence of the underlying surface topography on the change of speed of the average zonal wind at UV level at low latitudes, discovered by visual methods has been described in [3]. Analysis of the longitude-latitude distribution of the zonal and meridional components for 172000 (257 orbits) digital individual wind measurements at UV level and for 32,000 (150 orbits) digital individual wind measurements at IR level allows us to compare the influence of Venus topography on the change of the zonal and meridional components at both cloud levels. At the UV level (67±2 km) longitudinal profiles of the zonal speed for different latitude bins in low latitudes correlate with surface profiles. These correlations are most noticeable in the region of Aphrodite Terra. The correlation shift depends on the surface height. Albedo profiles correlate with surface profiles also at high latitudes. Zonal speed profiles at low latitude (5-15°S) depend not only on altitude, but also on local time. Minimum of the zonal speed is observed over Aphrodite Terra (90-100°E) at about 12 LT. A diurnal harmonic with an extremum over Aphrodite Terra was found. It can be considered as a superposition of a solar-synchronous tide and a stationary wave caused by interaction of the windstream with the surface. At the IR level (55±4 km) a correlation between surface topography and meridional speed was found in the region 10-30°S. The average meridional flow is equatorward at the IR level, but in the region Aphrodite Terra it is poleward. Acknowledgements: M.V. Patsaeva, I.V. Khatuntsev and J.-L. Bertaux were supported by the Ministry of Education and Science of Russian Federation grant 14.W03.31.0017. References: [1] Khatuntsev, I.V., M.V. Patsaeva, D.V. Titov, N.I. Ignatiev, A.V. Turin, S.S. Limaye, W.J. Markiewicz, M. Almeida, T. Roatsch and R. Moissl (2013), Cloud level winds from the Venus Express Monitoring Camera imaging., Icarus, 226, 140-158. [2] Patsaeva, M.V., I.V. Khatuntsev, D.V. Patsaev, D.V. Titov, N.I. Ignatiev, W.J. Markiewicz, A.V. Rodin (2015), The relationship between mesoscale circulation and cloud morphology at the upper cloud level of Venus from VMC/Venus Express, Planet. Space Sci. 113(08), 100-108, doi:10.1016/j.pss.2015.01.013. [3] Bertaux, J.-L., I. V. Khatuntsev, A. Hauchecorne, W. J. Markiewicz, E. Marcq, S. Lebonnois, M. Patsaeva, A. Turin, and A. Fedorova (2016), Influence of Venus topography on the zonal wind and UV albedo at cloud top level: The role of stationary gravity waves, J. Geophys. Res. Planets, 121, 1087-1101, doi:10.1002/2015JE004958.

Influence of Venus topography on the zonal wind and UV albedo at cloud top level: The role of stationary gravity waves

NASA Astrophysics Data System (ADS)

Bertaux, Jean-Loup; Khatuntsev, I. V.; Hauchecorne, A.; Markiewicz, W. J.; Marcq, E.; Lebonnois, S.; Patsaeva, M.; Turin, A.; Fedorova, A.

2016-06-01

Based on the analysis of UV images (at 365 nm) of Venus cloud top (altitude 67 ± 2 km) collected with Venus Monitoring Camera on board Venus Express (VEX), it is found that the zonal wind speed south of the equator (from 5°S to 15°S) shows a conspicuous variation (from -101 to -83 m/s) with geographic longitude of Venus, correlated with the underlying relief of Aphrodite Terra. We interpret this pattern as the result of stationary gravity waves produced at ground level by the uplift of air when the horizontal wind encounters a mountain slope. These waves can propagate up to the cloud top level, break there, and transfer their momentum to the zonal flow. Such upward propagation of gravity waves and influence on the wind speed vertical profile was shown to play an important role in the middle atmosphere of the Earth by Lindzen (1981) but is not reproduced in the current GCM of Venus atmosphere from LMD. (Laboratoire de Météorologie Dynamique) In the equatorial regions, the UV albedo at 365 nm varies also with longitude. We argue that this variation may be simply explained by the divergence of the horizontal wind field. In the longitude region (from 60° to -10°) where the horizontal wind speed is increasing in magnitude (stretch), it triggers air upwelling which brings the UV absorber at cloud top level and decreases the albedo and vice versa when the wind is decreasing in magnitude (compression). This picture is fully consistent with the classical view of Venus meridional circulation, with upwelling at equator revealed by horizontal air motions away from equator: the longitude effect is only an additional but important modulation of this effect. This interpretation is comforted by a recent map of cloud top H2O, showing that near the equator the lower UV albedo longitude region is correlated with increased H2O. We argue that H2O enhancement is the sign of upwelling, suggesting that the UV absorber is also brought to cloud top by upwelling.

Periodical oscillation of zonal wind velocities at the cloud top of Venus

NASA Astrophysics Data System (ADS)

Kouyama, T.; Imamura, T.; Nakamura, M.; Satoh, T.; Futaana, Y.

2010-12-01

Zonal wind velocity of Venus increases with height and reaches about 100 m s-1 at the cloud top level (~70km). The speed is approximately 60 times faster than the rotation speed of the solid body of Venus (~1.6 m s-1, at the equator) and this phenomenon is called a "super-rotation". From previous observations, it is known that the super-rotation changes on a long timescale. At the cloud top level, it was suggested that the super-rotation has a few years period oscillation based on observations made by Pioneer Venus orbiter of USA from 1979 to 1985 (Del Genio et al.,1990). However, the period, the amplitude, the spatial structure and the mechanism of the long period oscillation have not been understood well. Venus Express (VEX) of European Space Agency has been observing Venus since its orbital insertion in April 2006. Venus Monitoring Camera (VMC) onboard VEX has an ultra violet (UV) filter (365 nm), and VMC has taken day-side cloud images at the cloud top level with this filter. Such images exhibit various cloud features made by unknown UV absorber in the atmosphere. For investigating the characteristics of long-timescale variations of the super-rotation, we analyzed zonal velocity fields derived from UV cloud images from May 2006 to January 2010 using a cloud tracking method. UV imaging of VMC is done when the spacecraft is in the ascending portion of its elongated polar orbit. Since the orbital plane is nearly fixed in the inertial space, the local time of VMC/UV observation changes with a periodicity of one Venus year. As a result, periods when VMC observation covered day-side areas of Venus, large enough for cloud trackings, are not continuous. For deriving wind velocities we were able to use cloud images taken in 280 orbits during this period. The derived zonal wind velocity from 10°S to 40°S latitude shows a prominent year-to-year variation, and the variation is well fitted by a periodical oscillation with a period of about 260 Earth days, although not all phases of the variation were observed. The 260 day period is longer than the length of one day of Venus (~117 days) and somewhat longer than the orbital revolution period (~225 days) of Venus. In the equatorial region, the amplitude of this oscillation is about 12 m s-1 with the background zonal wind speed of about 95 m s-1. The oscillation period is shorter than the long-term oscillation reported by PVO. Such oscillation has not been reported most probably because previous Venus observations had limitations of observation chances to identify the oscillations with such a period.

SO2 on Venus: IUE, HST and ground-based measurements, and the active volcanism connection

NASA Technical Reports Server (NTRS)

Na, C. Y.; Barker, E. S.; Stern, S. A.; Esposito, L. W.

1993-01-01

Magellan images have shown that the volcanic features are widespread over the surface of Venus. The question of whether there is active volcanism is important for understanding both the atmospheric and the geological processes on Venus. The thick cloud cover of Venus precludes any direct observation of active volcanoes even if they exist. The only means of monitoring the active volcanism on Venus at present seems to be remote sensing from Earth. Continuous monitoring of SO2 is important to establish the long term trend of SO2 abundance and to understand the physical mechanism responsible for the change.

Venus Aerobot Surface Science Imaging System (VASSIS)

NASA Technical Reports Server (NTRS)

Greeley, Ronald

1999-01-01

The VASSIS task was to design and develop an imaging system and container for operation above the surface of Venus in preparation for a Discovery-class mission involving a Venus aerobot balloon. The technical goals of the effort were to: a) evaluate the possible nadir-viewed surface image quality as a function of wavelength and altitude in the Venus lower atmosphere, b) design a pressure vessel to contain the imager and supporting electronics that will meet the environmental requirements of the VASSIS mission, c) design and build a prototype imaging system including an Active-Pixel Sensor camera head and VASSIS-like optics that will meet the science requirements. The VASSIS science team developed a set of science requirements for the imaging system upon which the development work of this task was based.

The Reappearance of Venus Observed 8 October 2015

NASA Astrophysics Data System (ADS)

Dunham, David W.; Dunham, Joan B.

2018-01-01

The reappearance of Venus on October 8, 2015 offered a unique opportunity to attempt observation of the ashen light of Venus as the unlit side of Venus emerged from behind the dark side of the Moon. The dark side of Venus would be offered to observers without interference from the bright side of Venus or of the Moon. Observations were made from Alice Springs, Australia visually with a 20-cm Schmidt-Cassegrain and with a low-light level surveillance camera on a 25-cm reflector. No evidence of the dark side was noted by the visual observer, the video shows little indication of Venus prior to the bright side reappearance. The conclusion reached is that the ashen light, as it was classically defined, is not observable visually or with small telescopes in the visual regime.The presentation describes the prediction, observation technique, and various analyses by the authors and others to draw conclusions from the data.To date, the authors have been unable to locate any reports of others attempting to observe this unique event. That is a pity since, not only was it interesting for an attempt to verify past observations of the ashen light, it was also a visually stunning event.

Investigating the Concept of Using Airglow Measurements to Detect Seismicity on Venus

NASA Astrophysics Data System (ADS)

Kenda, Balthasar; Lognonné, Philippe; Komjathy, Attila; Banerdt, Bruce; Cutts, Jim; Soret, Lauriane; Jackson, Jennifer

2017-04-01

The internal structure and dynamics of Venus are poorly constrained by observations. Seismology is among the best candidates for probing the interior of the planet, and it would also provide indispensable information about the present-day tectonic activity of Venus. However, due to the extreme surface temperatures, a long-duration seismic station seems to be beyond the technical capabilities achievable today. Nonetheless, the thick and dense atmosphere, which strongly couples with the ground, gives rise to the attractive option of detecting seismic waves from quakes within the atmosphere itself (Garcia et al., 2005, Lognonné and Johnson, 2007, 2015) using in-situ or remote-sensing measurements (Cutts et al., 2015). Here, we consider the bright airglow emission of O2 at 1.27 μm on the nightside of Venus and we model the intensity fluctuations induced by Venus quakes. Synthetic seismograms in the airglow layer, at 90-120 km altitude, are computed using normal-mode summation for a fully coupled solid planet-atmosphere system, including the effects of molecular relaxation of CO2 and a radiative boundary condition at the top of the atmosphere (Lognonné et al., 2016). The corresponding variations in the volumetric emission rate, calculated for realistic background intensities of the airglow (Soret et al., 2012), are then vertically integrated to reproduce the signals that would be seen from orbit. The noise level of existing airglow cameras suggests that the Rayleigh waves generated by quakes of magnitude 5 and above occurring on the nightside of the planet may be detectable up to about 60° in epicentral distance. A significant advantage of this technique is that a single orbiting camera may be sufficient to serve the role of a seismic network. By identifying and tracking the waves it is indeed possible to locate the source, estimate the magnitude and measure the horizontal surface-wave propagation velocities on Venus. In particular, it is expected that this would significantly constrain seismicity on Venus and, through the analysis of Rayleigh-wave dispersion, the structure of the crust and upper mantle.

Cameras on the NEPTUNE Canada seafloor observatory: Towards monitoring hydrothermal vent ecosystem dynamics

NASA Astrophysics Data System (ADS)

Robert, K.; Matabos, M.; Sarrazin, J.; Sarradin, P.; Lee, R. W.; Juniper, K.

2010-12-01

Hydrothermal vent environments are among the most dynamic benthic habitats in the ocean. The relative roles of physical and biological factors in shaping vent community structure remain unclear. Undersea cabled observatories offer the power and bandwidth required for high-resolution, time-series study of the dynamics of vent communities and the physico-chemical forces that influence them. The NEPTUNE Canada cabled instrument array at the Endeavour hydrothermal vents provides a unique laboratory for researchers to conduct long-term, integrated studies of hydrothermal vent ecosystem dynamics in relation to environmental variability. Beginning in September-October 2010, NEPTUNE Canada (NC) will be deploying a multi-disciplinary suite of instruments on the Endeavour Segment of the Juan de Fuca Ridge. Two camera and sensor systems will be used to study ecosystem dynamics in relation to hydrothermal discharge. These studies will make use of new experimental protocols for time-series observations that we have been developing since 2008 at other observatory sites connected to the VENUS and NC networks. These protocols include sampling design, camera calibration (i.e. structure, position, light, settings) and image analysis methodologies (see communication by Aron et al.). The camera systems to be deployed in the Main Endeavour vent field include a Sidus high definition video camera (2010) and the TEMPO-mini system (2011), designed by IFREMER (France). Real-time data from three sensors (O2, dissolved Fe, temperature) integrated with the TEMPO-mini system will enhance interpretation of imagery. For the first year of observations, a suite of internally recording temperature probes will be strategically placed in the field of view of the Sidus camera. These installations aim at monitoring variations in vent community structure and dynamics (species composition and abundances, interactions within and among species) in response to changes in environmental conditions at different temporal scales. High-resolution time-series studies also provide a mean of studying population dynamics, biological rhythms, organism growth and faunal succession. In addition to programmed time-series monitoring, the NC infrastructure will also permit manual and automated modification of observational protocols in response to natural events. This will enhance our ability to document potentially critical but short-lived environmental forces affecting vent communities.

Sampling the Cloudtop Region on Venus

NASA Astrophysics Data System (ADS)

Limaye, Sanjay; Ashish, Kumar; Alam, Mofeez; Landis, Geoffrey; Widemann, Thomas; Kremic, Tibor

2014-05-01

The details of the cloud structure on Venus continue to be elusive. One of the main questions is the nature and identity of the ultraviolet absorber(s). Remote sensing observations from Venus Express have provided much more information about the ubiquitous cloud cover on Venus from both reflected and emitted radiation from Venus Monitoring Camera (VMC) and Visible InfraRed Imaging Spectrometer (VIRTIS) observations. Previously, only the Pioneer Venus Large Probe has measured the size distribution of the cloud particles, and other probes have measured the bulk optical properties of the cloud cover. However, the direct sampling of the clouds has been possible only below about 62 km, whereas the recent Venus Express observations indicate that the cloud tops extend from about 75 km in equatorial region to about 67 km in polar regions. To sample the cloud top region of Venus, other platforms are required. An unmanned aerial vehicle (UAV) has been proposed previously (Landis et al., 2002). Another that is being looked into, is a semi-buoyant aerial vehicle that can be powered using solar cells and equipped with instruments to not only sample the cloud particles, but also to make key atmospheric measurements - e.g. atmospheric composition including isotopic abundances of noble and other gases, winds and turbulence, deposition of solar and infrared radiation, electrical activity. The conceptual design of such a vehicle can carry a much more massive payload than any other platform, and can be controlled to sample different altitudes and day and night hemispheres. Thus, detailed observations of the surface using a miniature Synthetic Aperture Radar are possible. Data relay to Earth will need an orbiter, preferably in a low inclination orbit, depending on the latitude region selected for emphasis. Since the vehicle has a large surface area, thermal loads on entry are low, enabling deployment without the use of an aeroshell. Flight characteristics of such a vehicle have been studied (Alam et al., 2014; Kumar et al., 2014) Acknowledgements Mr. Ashish Kumar and Mr. Mofeez Alam were supported by the Indo US Forum for Science and Technology (IUSSTF) as S.N. Bose Scholars at the University of Wisconsin, Madison as Summer interns. We are grateful for the guidance support provided by Dr. Kristen Griffin and Dr. Daniel Sokol, Northrop Grumman Aerospace Corporation. References Alam, M., K. Ashish, and S.S. Limaye. Aerodynamic Analysis of BlimPlane- a Conceptual Hybrid UAV for Venus Exploration. Accepted for publication, 2014 IEEE Aerospace Conference, Big Sky, Montana, 1-8 March 2014. Ashish, K., M. Alam, and S.S. Limaye, Flight Analysis of a Venus Atmospheric Mobile Platform. Accepted for publication, 2014 IEEE Aerospace Conference, Big Sky, Montana, 1-8 March 2014. Landis, G.A., A. Colozza, C.M. LaMarre, Atmospheric flight on Venus. NASA/TM—2002-211467, AIAA-2001-0819, June 2002

The cartography of Venus with Magellan data

NASA Technical Reports Server (NTRS)

Kirk, R. L.; Morgan, H. F.; Russell, J. F.

1993-01-01

Maps of Venus based on Magellan data are being compiled at 1:50,000,000, 1:5,000,000 and 1:1,500,000 scales. Topographic contour lines based on radar altimetry data are overprinted on the image maps, along with feature nomenclature. Map controls are based on existing knowledge of the spacecraft orbit; photogrammetric triangulation, a traditional basis for geodetic control for bodies where framing cameras were used, is not feasible with the radar images of Venus. Preliminary synthetic aperture radar (SAR) image maps have some data gaps and cosmetic inconsistencies, which will be corrected on final compilations. Eventual revision of geodetic controls and of the adopted Venusian spin-axis location will result in geometric adjustments, particularly on large-scale maps.

Investigating the Geophysics of Venus: Result of the post-Alpbach Summer School 2014

NASA Astrophysics Data System (ADS)

Koopmans, Robert-Jan; Łosiak, Anna; Białek, Agata; Donohoe, Anthony; Fernández Jiménez, María; Frasl, Barbara; Gurciullo, Antonio; Kleinschneider, Andreas; Mannel, Thurid; Muñoz Elorza, Iñigo; Nilsson, Daniel; Oliveira, Marta; Sørensen-Clark, Paul; Timoney, Ryan; van Zelst, Iris

2015-04-01

Venus has been investigated by only five dedicated mission programs since the beginning of space flight. This relatively low level of interest is remarkable when considering that mass and radius of Venus are very similar to Earth's, while at the same time characteristics such as spin rate, atmospheric composition, pressure and temperature, make Venus a very different, inhabitable world. The underlying causes of these differences are not well understood. Apprehending Venus' tectonics and internal structure would not only shed light on the question why those two planets evolved so differently, but also help refining current models of planetary systems formation. In order to answer the question about reasons for differences in evolution of those two planets a group of 15 young scientists and engineers designed a mission to Venus during a follow-up of the Alpbach Summer School 2014. The primary objective of this mission is to learn whether Venus is tectonically active and on what time scale. In order to accomplish this goal the mission will determine the crustal structure of Venus, the current activity and distribution of active volcanoes and the movement of continental plates. The secondary objective is to further constrain the models of Venus' internal structure and composition. To achieve this, the mission will investigate the size, state and composition of the core as well as the state and composition of the mantle. The proposed mission consists of an orbiter in a near-polar circular orbit around Venus and a balloon for in-situ measurements operating during the initial phase of the mission. The balloon carries a nephelometer, a magnetometer, a mass spectrometer and stereo microphones and meteorological package. The orbiter carries a gradiometer for determining the gravity field, a synthetic aperture radar for investigating small changes in surface topography and mapping microwave signals from the surface and an IR and UV spectrometer and IR camera for monitoring heat signatures from volcanoes. By using the previous landers as reference points it will also be possible to accurately determine the spin rate with the radar. The nominal mission duration is planned to be five years starting from the release of the balloon. The balloon will operate for 25 days during which it oscillates vertically in the atmosphere between an altitude of 40 and 60 kilometres in a period of about six hours. At the same time, due to prevailing wind directions on Venus, it will gradually spiral from the equator towards higher latitudes. During the balloon science phase the orbiter will be in an elliptical orbit to maximise the time of visibility of the balloon with the orbiter. After this phase, the orbiter will be brought into a circular orbit at an altitude of 250 kilometres. To save fuel, apoapsis lowering will be achieved by aerobreaking in Venus' atmosphere. In the presentation further details about the mission timeline will be given. Particular engineering problems such as thermal control and data communication and the proposed solutions will be presented.

The MVM imaging system and its spacecraft interactions. [Mariner Venus/Mercury TV system performance

NASA Technical Reports Server (NTRS)

Vescelus, F. E.

1975-01-01

The present work describes the main considerations and steps taken in determining the functional design of the imaging system of the Mariner Venus/Mercury (MVM) spacecraft and gives examples of some of the interactions between the spacecraft and the imaging instrument during the design and testing phases. Stringent cost and scheduling constraints dictated the use of the previous Mariner 9 dual-camera TV system. The TV parameters laid the groundwork for the imaging definition. Based on the flyby distances from Venus and Mercury and the goal of surface resolution better than 500 meters per sample pair, calculation was performed on focal length, format size, planetary coverage, and data rates. Some problems encountered in initial mechanical operation and as a result of spacecraft drift during the mission are also discussed.

CUVE - Cubesat UV Experiment: Unveil Venus' UV Absorber with Cubesat UV Mapping Spectrometer

NASA Astrophysics Data System (ADS)

Cottini, V.; Aslam, S.; D'Aversa, E.; Glaze, L.; Gorius, N.; Hewagama, T.; Ignatiev, N.; Piccioni, G.

2017-09-01

Our Venus mission concept Cubesat UV Experiment (CUVE) is one of ten proposals selected for funding by the NASA PSDS3 Program - Planetary Science Deep Space SmallSat Studies. CUVE concept is to insert a CubeSat spacecraft into a Venusian orbit and perform remote sensing of the UV spectral region using a high spectral resolution point spectrometer to resolve UV molecular bands, observe nightglow, and characterize the unidentified main UV absorber. The UV spectrometer is complemented by an imaging UV camera with multiple bands in the UV absorber main band range for contextual imaging. CUVE Science Objectives are: the nature of the "Unknown" UV-absorber; the abundances and distributions of SO2 and SO at and above Venus's cloud tops and their correlation with the UV absorber; the atmospheric dynamics at the cloud tops, structure of upper clouds and wind measurements from cloud-tracking; the nightglow emissions: NO, CO, O2. This mission will therefore be an excellent platform to study Venus' cloud top atmospheric properties where the UV absorption drives the planet's energy balance. CUVE would complement past, current and future Venus missions with conventional spacecraft, and address critical science questions cost effectively.

PIONEER VENUS 2 MULTI PROBE IS ENCAPSULATED IN PROTECTIVE SHROUD

NASA Technical Reports Server (NTRS)

1978-01-01

Encapsulation of the Pioneer Venus Multiprobe in its protective nose fairing is closely monitored by technicians in Hangar AO. The 2,000-pound spacecraft is one of two being launched toward the planet Venus. The Multiprobe is scheduled for launch aboard an Atlas Centaur rocket on August 7. Flying a direct path to the cloud-shrouded planet, the Multiprobe will reach Venus five days after the arrival of its sister spacecraft, the Pioneer Venus Orbiter, which was launched May 20, 1978. Three weeks before the Multiprobe reaches Venus, its four heavily instrumented scientific probes (seen on top of the spacecraft's main body or ''bus'') will be released and will impact at various points on the planet's surface. Together, the two spacecraft will conduct a thorough scientific exploration of the planet Venus.

UVMAS: Venus ultraviolet-visual mapping spectrometer

NASA Astrophysics Data System (ADS)

Bellucci, G.; Zasova, L.; Altieri, F.; Nuccilli, F.; Ignatiev, N.; Moroz, V.; Khatuntsev, I.; Korablev, O.; Rodin, A.

This paper summarizes the capabilities and technical solutions of an Ultraviolet Visual Mapping Spectrometer designed for remote sensing of Venus from a planetary orbiter. The UVMAS consists of a multichannel camera with a spectral range 0.19 << 0.49 μm which acquires data in several spectral channels (up to 400) with a spectral resolution of 0.58 nm. The instantaneous field of view of the instrument is 0.244 × 0.244 mrad. These characteristics allow: a) to study the upper clouds dynamics and chemistry; b) giving constraints on the unknown absorber; c) observation of the night side airglow.

MARINER 10 LAUNCH VEHICLE ATLAS CENTAUR 34 UNDERGOES TANKING TEST AT LAUNCH COMPLEX 36B

NASA Technical Reports Server (NTRS)

1973-01-01

Atlas Centaur 34, undergoes tanking test on NASA Complex 36B at Cape Kennedy, Fla. Atlas Centaur 34 is under preparation to launch history's first duel-planet flight, the Mariner mission to Venus and Mercury, scheduled for early November. With all events going as planned, the Mariner spacecraft will fly by Venus in early February, 1974, and reach Mercury in late march, 1974. The spacecraft, Mariner 10, will carry two television cameras to photograph the planets, and six other scientific experiments to return planetary and interplanetary data back to Earth.

Search for ongoing volcanic activity on Venus: Case study of Maat Mons, Sapas Mons and Ozza Mons

NASA Astrophysics Data System (ADS)

Basilevsky, A. T.; Shalygin, E. V.; Markiewicz, W. J.; Titov, D. V.; Roatsch, Th.; Kreslavsky, M. A.

2012-04-01

Maat Mons volcano and its vicinities show evidence of geologically very recent volcanism. We consider Venus Monitoring Camera (VMC) night-side images of this area. Analysis of VMC images taken in 12 observation sessions during the time period from 31 Oct 2007 to 15 Jun 2009 did not reveal any suspicious high-emission spots which could be signatures of the presently ongoing volcanic eruptions. If Maat Mons volcano had the eruption history similar to that of Mauna Loa, Hawaii, in the 20th century, the probability to observe an eruption in this VMC observation sequence would be about 8%, meaning that the absence of detection does not mean that Maat is not active in the present epoch. Blurring of the thermal radiation coming from Venus surface by the planet atmosphere decreases detectability of thermal signature of fresh lavas. We simulated near-infrared images of the study area with artificially added lava flows having surface temperature 1000 K and various areas. These simulations showed that 1 km2 lava flows should be marginally seen by VMC. An increase of the lava surface area to 2 - 3 km2 makes them visible on the plains and increase of the area to 4 - 5 km2 makes them visible even in deep rift zones. Typical individual lava flows on Mauna Loa are a few km2, however, they often have been formed during weeks to months and the instantaneous size of the hot flow surface was usually much smaller. Thus the detection probability is significantly lower than 8%, but it is far from negligible. Our consideration suggests that further search of Maat Mons area and other areas including young rift zones makes sense and should be continued. More effective search could be done if observations simultaneously cover most part of the night side of Venus for relatively long (years) time of continuous observations.

JPL Closeup

NASA Technical Reports Server (NTRS)

1983-01-01

Voyager, Infrared Astronomical Satellite, Galileo, Viking, Solar Mesosphere Explorer, Wide-field/Planetary Camera, Venus Mapper, International Solar Polar Mission - Solar Interplanetary Satellite, Extreme Ultraviolet Explores, Starprobe, International Halley Watch, Marine Mark II, Samex, Shuttle Imaging Radar-A, Deep Space Network, Biomedical Technology, Ocean Studies and Robotics are summarized.

Venus surface optical imaging from a balloon or a probe during descent : Monte Carlo simulation and the proposal of the experiment on TV-camera in transparency windows of a 1.02 and 0.85 microns

NASA Astrophysics Data System (ADS)

Ekonomov, A.

2011-10-01

The problem of imaging of the planet surfaces is a priority for space exploration, since the surface is crucial to study the origin mechanisms . However, if for other planets in the solar system conducted hundreds of experiments in this direction, for Venus there are only a few . This is due to an optically dense cloud cover in the upper atmosphere of Venus. Until now, the global picture is obtained only in radio wavelengths. First spacecraft to the board which was carried out large-scale location of Venus was on the Pioneer Venus Orbiter (1978), which carried out radar mapping of the surface. AMS Venus 15/16 (1978) have got on board the DBR with a resolution of 1-2 km, and Magellan (1989) had a DBR with a resolution of 100 m. During 1975-1982 Soviet leanders, being on a surface, have taken a number of panoramas with the high resolution of the order of shares of meter. Thus, there is a gap between the resolution of 100 m and shares of meter and it should be filled. Such experiment could be imaging from undercloud layer in a transparency window of 1 microns. Idea is not new, but technical study was not conducted.

Venus surface optical imaging from a balloon or a probe during descent : Monte Carlo simulation and the proposal of the experiment on TV-camera in transparency windows of a 1.02 and 0.85 microns.

NASA Astrophysics Data System (ADS)

Ekonomov, A.

2011-10-01

The problem of imaging of the planet surfaces is a priority for space exploration, since the surface is crucial to study the origin mechanisms . However, if for other planets in the solar system conducted hundreds of experiments in this direction, for Venus there are only a few . This is due to an optically dense cloud cover in the upper atmosphere of Venus. Until now, the global picture is obtained only in radio wavelengths. First spacecraft to the board which was carried out large-scale location of Venus was on the Pioneer Venus Orbiter (1978), which carried out radar mapping of the surface. AMS Venus 15/16 (1978) have got on board the DBR with a resolution of 1-2 km, and Magellan (1989) had a DBR with a resolution of 100 m. During 1975-1982 Soviet leanders, being on a surface, have taken a number of panoramas with the high resolution of the order of shares of meter. Thus, there is a gap between the resolution of 100 m and shares of meter and it should be filled. Such experiment could be imaging from undercloud layer in a transparency window of 1 microns. Idea is not new, but technical study was not conducted.

Field-of-View Guiding Camera on the HISAKI (SPRINT-A) Satellite

NASA Astrophysics Data System (ADS)

Yamazaki, A.; Tsuchiya, F.; Sakanoi, T.; Uemizu, K.; Yoshioka, K.; Murakami, G.; Kagitani, M.; Kasaba, Y.; Yoshikawa, I.; Terada, N.; Kimura, T.; Sakai, S.; Nakaya, K.; Fukuda, S.; Sawai, S.

2014-11-01

HISAKI (SPRINT-A) satellite is an earth-orbiting Extreme UltraViolet (EUV) spectroscopic mission and launched on 14 Sep. 2013 by the launch vehicle Epsilon-1. Extreme ultraviolet spectroscope (EXCEED) onboard the satellite will investigate plasma dynamics in Jupiter's inner magnetosphere and atmospheric escape from Venus and Mars. EUV spectroscopy is useful to measure electron density and temperature and ion composition in plasma environment. EXCEED also has an advantage to measure spatial distribution of plasmas around the planets. To measure radial plasma distribution in the Jovian inner magnetosphere and plasma emissions from ionosphere, exosphere and tail separately (for Venus and Mars), the pointing accuracy of the spectroscope should be smaller than spatial structures of interest (20 arc-seconds). For satellites in the low earth orbit (LEO), the pointing displacement is generally caused by change of alignment between the satellite bus module and the telescope due to the changing thermal inputs from the Sun and Earth. The HISAKI satellite is designed to compensate the displacement by tracking the target with using a Field-Of-View (FOV) guiding camera. Initial checkout of the attitude control for the EXCEED observation shows that pointing accuracy kept within 2 arc-seconds in a case of "track mode" which is used for Jupiter observation. For observations of Mercury, Venus, Mars, and Saturn, the entire disk will be guided inside slit to observe plasma around the planets. Since the FOV camera does not capture the disk in this case, the satellite uses a star tracker (STT) to hold the attitude ("hold mode"). Pointing accuracy during this mode has been 20-25 arc-seconds. It has been confirmed that the attitude control works well as designed.

Venus mapping

NASA Technical Reports Server (NTRS)

Batson, R. M.; Morgan, H. F.; Sucharski, Robert

1991-01-01

Semicontrolled image mosaics of Venus, based on Magellan data, are being compiled at 1:50,000,000, 1:10,000,000, 1:5,000,000, and 1:1,000,000 scales to support the Magellan Radar Investigator (RADIG) team. The mosaics are semicontrolled in the sense that data gaps were not filled and significant cosmetic inconsistencies exist. Contours are based on preliminary radar altimetry data that is subjected to revision and improvement. Final maps to support geologic mapping and other scientific investigations, to be compiled as the dataset becomes complete, will be sponsored by the Planetary Geology and Geophysics Program and/or the Venus Data Analysis Program. All maps, both semicontrolled and final, will be published as I-maps by the United States Geological Survey. All of the mapping is based on existing knowledge of the spacecraft orbit; photogrammetric triangulation, a traditional basis for geodetic control on planets where framing cameras were used, is not feasible with the radar images of Venus, although an eventual shift of coordinate system to a revised spin-axis location is anticipated. This is expected to be small enough that it will affect only large-scale maps.

Laboratory simulations of volcanic ash charging and conditions for volcanic lightning on Venus

NASA Astrophysics Data System (ADS)

Airey, Martin; Warriner-Bacon, Elliot; Aplin, Karen

2017-04-01

Lightning may be important in the emergence of life on Earth and elsewhere, as significant chemical reactions occur in the superheated region around the lightning channel. This, combined with the availability of phosphates in volcanic clouds, suggests that volcanic lightning could have been the catalyst for the formation of biological compounds on the early Earth [1]. In addition to meteorological lightning, volcanic activity also generates electrical discharges within charged ash plumes, which can be a significant contributor to atmospheric electricity on geologically active planets. The physical properties of other planetary atmospheres, such as that of Venus, have an effect on the processes that lead to the generation of volcanic lightning. Volcanism is known to have occurred on Venus in the past, and recent observations made by ESA's Venus Express satellite have provided evidence for currently active volcanism [2-4], and lightning discharges [e.g. 5]. Venusian lightning could potentially be volcanic in origin, since no meteorological mechanisms are known to separate charge effectively in its clouds [6]. The hunt for further evidence for lightning at Venus is ongoing, for example by means of the Lightning and Airglow Camera (LAC) [7] on Akatsuki, the current JAXA mission at Venus. Our laboratory experiments simulate ash generation and measure electrical charging of the ash under typical atmospheric conditions on Earth and Venus. The study uses a 1 litre chamber, which, when pressurised and heated, can simulate the high-pressure, high-temperature, carbon dioxide-dominated atmosphere of Venus at 10 km altitude ( 5 MPa, 650 K). A key finding of previous work [8] is that ash plume-forming eruptions are more likely to occur at higher altitudes such as these on Venus. The chamber contains temperature/pressure monitoring and logging equipment, a rock collision apparatus (based on [9]) to generate the charged rock fragments, and charge measurement electrodes connected to a high-precision electrometer. The separate effects of varying the atmospheric composition, temperature, and pressure on the charges attained and the relationship between particle size and charge polarity will be addressed, and the implications discussed. The key questions considered here are: (a) is volcanic activity a feasible mechanism for lightning generation on Venus, (b) how do the extreme environmental conditions on Venus affect the mechanisms required to generate lightning, (c) what are the implications for volcanic lightning's role in the emergence of life on other planets? [1] Navarro-Gonzalez, R. and Segura, A., (2001) Volcanic lightning and the availability of reactive nitrogen and phosphorus for chemical evolution. [2] Marcq, E., et al. (2012) Nature Geoscience, 1-4 [3] Shalygin, E.V., et al. (2015) Geophys. Res. Lett., 42 [4] Smrekar, S.E., et al. (2010) Science, 328, 5978, 605-608 [5] Russell, C.T., et al. (2008) Journal of Geophysical Research-Planets, 113 [6] Aplin, K.L. and Fischer, G. (In press) Weather, (preprint at https://arxiv.org/abs/1606.03285) [7] Takahashi, Y., et al. (2008) Space Sci. Rev., 137, 1-4, 317-334 [8] Airey, M.W., et al. (2015) Planetary and Space Science, 113-114, 33-48 [9] James, M.R., et al. (2000) Journal of Geophysical Research-Solid Earth, 105, B7, 16641-16649

Using manufacturing message specification for monitor and control at Venus

NASA Technical Reports Server (NTRS)

Heuser, W. Randy; Chen, Richard L.; Stockett, Michael H.

1993-01-01

The flexibility and robustness of a monitor and control (M&C) system are a direct result of the underlying interprocessor communications architecture. A new architecture for M&C at the Deep Space Communications Complexes (DSCC's) has been developed based on the Manufacturing Message Specification (MMS) process control standard of the Open System Interconnection (OSI) suite of protocols. This architecture has been tested both in a laboratory environment and under operational conditions at the Deep Space Network (DSN) experimental Venus station (DSS-13). The Venus experience in the application of OSI standards to support M&C has been extremely successful. MMS meets the functional needs of the station and provides a level of flexibility and responsiveness previously unknown in that environment. The architecture is robust enough to meet current operational needs and flexible enough to provide a migration path for new subsystems. This paper will describe the architecture of the Venus M&C system, discuss how MMS was used and the requirements this imposed on other parts of the system, and provide results from systems and operational testing at the Venus site.

Geographic distribution of zonal wind and UV albedo at cloud top level from VMC camera on Venus Express: Influence of Venus topography through stationary gravity waves vertical propagation.

NASA Astrophysics Data System (ADS)

Bertaux, Jean-Loup; Khatunstsev, Igor; Hauchecorne, Alain; Markiewicz, Wojciech; Marcq, Emmanuel; Lebonnois, Sébastien; Patsaeva, Marina; Turin, Alexander

2015-04-01

UV images (at 365 nm) of Venus cloud top collected with VMC camera on board Venus Express allowed to derive a large number of wind measurements at altitude 67±2 km from tracking of cloud features in the period 2006-2012. Both manual (45,600) and digital (391,600) individual wind measurements over 127 orbits were analyzed showing various patterns with latitude and local time. A new longitude-latitude geographic map of the zonal wind shows a conspicuous region of strongly decreased zonal wind, a remarkable feature that was unknown up to now. While the average zonal wind near equator (from 5°S to 15°s) is -100.9 m/s in the longitude range 200-330°, it reaches -83.4 m/s in the range 60-100°, a difference of 17.5 m/s. When compared to the altimetry map of Venus, it is found that the zonal wind pattern is well correlated with the underlying relief in the region of Aphrodite Terra, with a downstream shift of about 30° (˜3,200 km). We interpret this pattern as the result of stationary gravity waves produced at ground level by the up lift of air when the horizontal wind encounters a mountain slope. These waves can propagate up to cloud top level, break there and transfer their momentum to the zonal flow. A similar phenomenon is known to operate on Earth with an influence on mesospheric winds. The LMD-GCM for Venus was run with or without topography, with and without a parameterization of gravity waves and does not display such an observed change of velocity near equator. The cloud albedo map at 365 nm varies also in longitude and latitude. We speculate that it might be the result of increased vertical mixing associated to wave breaking, and decreased abundance of the UV absorber which makes the contrast in images. The impact of these new findings on current super rotation theories remains to be assessed. This work was triggered by the presence of a conspicuous peak at 117 days in a time series of wind measurements. This is the length of the solar day as seen at the ground of Venus. Since VMC measurements are done preferably in a local time window centred on the sub-solar point, any parameter having a geographic longitude dependence will show a peak at 117 days.

Experimental results from the VENUS-F critical reference state for the GUINEVERE accelerator driven system project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Uyttenhove, W.; Baeten, P.; Ban, G.

The GUINEVERE (Generation of Uninterrupted Intense Neutron pulses at the lead Venus Reactor) project was launched in 2006 within the framework of FP6 EUROTRANS in order to validate on-line reactivity monitoring and subcriticality level determination in Accelerator Driven Systems. Therefore the VENUS reactor at SCK.CEN in Mol (Belgium) was modified towards a fast core (VENUS-F) and coupled to the GENEPI-3C accelerator built by CNRS The accelerator can operate in both continuous and pulsed mode. The VENUS-F core is loaded with enriched Uranium and reflected with solid lead. A well-chosen critical reference state is indispensable for the validation of the on-linemore » subcriticality monitoring methodology. Moreover a benchmarking tool is required for nuclear data research and code validation. In this paper the design and the importance of the critical reference state for the GUINEVERE project are motivated. The results of the first experimental phase on the critical core are presented. The control rods worth is determined by the rod drop technique and the application of the Modified Source Multiplication (MSM) method allows the determination of the worth of the safety rods. The results are implemented in the VENUS-F core certificate for full exploitation of the critical core. (authors)« less

Experimental results from the VENUS-F critical reference state for the GUINEVERE accelerator driven system project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Uyttenhove, W.; Baeten, P.; Kochetkov, A.

The GUINEVERE (Generation of Uninterrupted Intense Neutron pulses at the lead Venus Reactor) project was launched in 2006 within the framework of FP6 EUROTRANS in order to validate online reactivity monitoring and subcriticality level determination in accelerator driven systems (ADS). Therefore, the VENUS reactor at SCK.CEN in Mol, Belgium, was modified towards a fast core (VENUS-F) and coupled to the GENEPI-3C accelerator built by CNRS. The accelerator can operate in both continuous and pulsed mode. The VENUS-F core is loaded with enriched Uranium and reflected with solid lead. A well-chosen critical reference state is indispensable for the validation of themore » online subcriticality monitoring methodology. Moreover, a benchmarking tool is required for nuclear data research and code validation. In this paper, the design and the importance of the critical reference state for the GUINEVERE project are motivated. The results of the first experimental phase on the critical core are presented. The control rods worth is determined by the positive period method and the application of the Modified Source Multiplication (MSM) method allows the determination of the worth of the safety rods. The results are implemented in the VENUS-F core certificate for full exploitation of the critical core. (authors)« less

The latest views of Venus as observed by the Japanese Orbiter "Akatsuki"

NASA Astrophysics Data System (ADS)

Satoh, Takehiko; Akatsuki Project Team

2016-10-01

Akatsuki, also known as the Venus Climate Orbiter (VCO) of Japan, was launched on 21 May 2010 from Tanegashima Space Center, Kagoshima, Japan. After 6 months of cruising to Venus, an attempt was made to insert Akatsuki in Venus orbit (VOI) on 7 December 2010. However, due to the clogged check valve in a pressurizing system of fuel line, the thrust to decelerate the spacecraft was not enough to allow it captured by the gravitational pull of Venus. After this failure, Akatsuki became an artificial planet around the sun with an orbital period of ~200 days. We waited for 5 earth years (or 9 Akatsuki years), and the second attempt (VOI-R1) was made on the same day, 7 December 2015. It was a great surprise to the world that a "once failed" spacecraft made a successful orbital insertion after many years of time. The orbital period around Venus is slightly shorter than 11 days, with the apoapsis altitude of ~0.37 million km.After Venus Express (VEX), which was in Venus orbit for 8 years, Akatsuki still keeps a unique position and is expected to make a great contribution to the Venus science due primarily to its orbit. In contrast to the polar orbits of Pioneer Venus or VEX, Akatsuki is in a near-equatorial plane and revolves westward, the same direction as the super rotating atmosphere. This orbit allows the spacecraft in a "partial" synchronization with the atmospheric motion when Akatsuki is near the planet. When at greater distances, the atmosphere moves faster than Akatsuki's orbital motion so the spacecraft maps the full longitude range of Venus in several days. This meteorological-satellite-like concept makes Akatsuki the most unique planetary orbiter in the history. To sense the various levels of the atmosphere, to draw 3-dimentional picture of dynamics, Akatsuki is equipped with 5 on-board cameras, UVI (283 and 365 nm wavelength), IR1 (0.90, 0.97, and 1.01 μm), IR2 (1.65, 1.735, 2.02, 2.26, and 2.32 μm), LIR (8-12 μm), and LAC (a special high-speed sensor at visible wavelengths), as well as the ultra-stable oscillator for radio-occultation measurements.At the lecture, the latest views of Venus as acquired with these instruments on Akatsuki will be presented.

First ever in-situ density measurements in Venus' polar upper atmosphere by combined drag and torque measurements

NASA Astrophysics Data System (ADS)

Svedhem, Håkan; Mueller, Michael; Mueller-Wodarg, Ingo

Information on the atmospheric density in the altitude range 150-200 km in the atmosphere of Venus is difficult to gather remotely. The Pioneer Venus Orbiter Neutral Mass Spectrometer measured gas densities in the equatorial upper atmosphere in-situ, but no such measurements have ever been made in the polar regions of Venus. The Venus Express spacecraft on its orbit approaches the planet in the northern polar region, but is not equipped with a mass spectrometer instrument for in-situ gas density measurements. By reducing the pericentre altitude the total mass density can however be measured in situ by monitoring the orbital decay caused by the drag on the spacecraft by the atmosphere via direct tracking of the Doppler signal on the telecommunication link. Such measurements have been performed with Venus Express several times during the last year as part of the Venus Express Atmospheric Drag Experiment (VExADE). The results indicate a large variability within only a few days and have led to questions if these variations are real or within the uncertainty of the measurements. A completely different and independent measurement is given by monitoring the torque asserted by the atmosphere on the spacecraft. This is done by monitoring the momentum accumulated in the reaction wheels during the pericentre pass and at the same time considering all other perturbing forces. This requires the spacecraft to fly in an asymmetric attitude with respect to the centre of gravity, centre of drag and the velocity vector. This technique has proven very sensitive, in particular if the asymmetry is large, and offers a further method of measuring atmospheric densities in-situ that previously had not been explored with the Venus Express spacecraft. Similar measurements have been done in the past by Magellan at Venus and by Cassini at Titan. First torque measurements carried out during last years' low pericentre passes have confirmed the density measurements by the VExADE drag measurements to an amazingly good accuracy and added to the confidence in the results from these measurements. New combined measurements, where the asymmetry is increased by rotating the solar panels, are planned for February and April 2010. The new results will be discussed at the meeting.

Venus Express en route to probe the planet's hidden mysteries

NASA Astrophysics Data System (ADS)

2005-11-01

Venus Express will eventually manoeuvre itself into orbit around Venus in order to perform a detailed study of the structure, chemistry and dynamics of the planet's atmosphere, which is characterised by extremely high temperatures, very high atmospheric pressure, a huge greenhouse effect and as-yet inexplicable "super-rotation" which means that it speeds around the planet in just four days. The European spacecraft will also be the first orbiter to probe the planet's surface while exploiting the "visibility windows" recently discovered in the infrared waveband. The 1240 kg mass spacecraft was developed for ESA by a European industrial team led by EADS Astrium with 25 main contractors spread across 14 countries. It lifted off onboard a Soyuz-Fregat rocket, the launch service being provided by Starsem. The lift-off from the Baikonur Cosmodrome in Kazakstan this morning took place at 09:33 hours local time (04:33 Central European Time). Initial Fregat upper-stage ignition took place 9 minutes into the flight, manoeuvring the spacecraft into a low-earth parking orbit. A second firing, 1 hour 22 minutes later, boosted the spacecraft to pursue its interplanetary trajectory. Contact with Venus Express was established by ESA's European Space Operations Centre (ESOC) at Darmstadt, Germany approximately two hours after lift-off. The spacecraft has correctly oriented itself in relation to the sun and has deployed its solar arrays. All onboard systems are operating perfectly and the orbiter is communicating with the Earth via its low-gain antenna. In three days' time, it will establish communications using its high-gain antenna. Full speed ahead for Venus Venus Express is currently distancing itself from the Earth full speed, heading on its five-month 350 million kilometre journey inside our solar system. After check-outs to ensure that its onboard equipment and instrument payload are in proper working order, the spacecraft will be mothballed, with contact with the Earth being reduced to once daily. If needed, trajectory correction manoeuvres can go ahead at the half-way stage in January. When making its closest approach, Venus Express will face far tougher conditions than those encountered by Mars Express on nearing the Red Planet. For while Venus's size is indeed similar to that of the Earth, its mass is 7.6 times that of Mars, with gravitational attraction to match. To resist this greater gravitational pull, the spacecraft will have to ignite its main engine for 53 minutes in order to achieve 1.3 km/second deceleration and place itself into a highly elliptical orbit around the planet. Most of its 570 kg of propellant will be used for this manoeuvre. A second engine firing will be necessary in order to reach final operational orbit: a polar elliptical orbit with 12-hour crossings. This will enable the probe to make approaches to within 250 km of the planet's surface and withdraw to distances of up to 66 000 km, so as to carry out close-up observations and also get an overall perspective. Exploring other planets to better understand planet Earth "The launch of Venus Express is a further illustration of Europe's determination to study the various bodies in our solar system", stressed Professor David Southwood, the Director of ESA's science programmes. "We started in 2003 with the launch of Mars Express to the Red Planet and Smart-1 to the Moon and both these missions have amply exceeded our expectations. Venus Express marks a further step forward, with a view to eventually rounding off our initial overview of our immediate planetary neighbours with the BepiColombo mission to Mercury to be launched in 2013." "With Venus Express, we fully intend to demonstrate yet again that studying the planets is of vital importance for life here on Earth", said Jean Jacques Dordain, ESA Director General. "To understand climate change on Earth and all the contributing factors, we cannot make do with solely observing our own planet. We need to decipher the mechanics of the planetary atmosphere in general terms. With Mars Express, we are studying the Martian atmosphere. With Huygens, we have explored that of Saturn's satellite Titan. And now with Venus Express, we are going to add a further specimen to our collection. Originally, Venus and the Earth must have been very similar planets. So we really do need to understand why and how they eventually diverged to the point that one became a cradle for life while the other developed into a hostile environment." The Venus Express mission is planned to last at least two Venusian days (486 Earth days) and may be extended, depending on the spacecraft's operational state of health. Twin sister of Mars Express Venus Express largely reuses the architecture developed for Mars Express. This has reduced manufacturing cycles and halved the mission cost, while still targeting the same scientific goals. Finally approved in late 2002, Venus Express was thereby developed fast, indeed in record time, to be ready for its 2005 launch window. However, Venusian environmental conditions are very different to those encountered around Mars. Solar flux is four times higher and it has been necessary to adapt the spacecraft design to this hotter environment, notably by entirely redesigning the thermal insulation. Whereas Mars Express sought to retain heat to enable its electronics to function properly, Venus Express will in contrast be aiming for maximum heat dissipation in order to stay cool. The solar arrays on Venus Express have been completely redesigned. They are shorter and are interspersed with aluminium strips to help reject some solar flux to protect the spacecraft from temperatures topping 250ºC. It has even been necessary to protect the rear of the solar arrays - which normally remain in shadow - in order to counter heat from solar radiation reflected by the planet's atmosphere. An atmosphere of mystery Following on from the twenty or so American and Soviet missions to the planet carried out since 1962, Venus Express will endeavour to answer many of the questions raised by previous missions but so far left unanswered. It will focus on the characteristics of the atmosphere, its circulation, structure and composition in relation to altitude, and its interactions with the planet's surface and with the solar wind at altitude. To perform these studies, it has seven instruments onboard: three are flight-spare units of instruments already flown on Mars Express, two are from comet-chaser Rosetta and two were designed specifically for this mission. The PFS high-resolution spectrometer will measure atmospheric temperature and composition at varying altitudes. It will also measure surface temperature and search for signs of current volcanic activity. The SPICAV/SOIR infrared & ultraviolet spectrometer and the VeRa instrument will also probe the atmosphere, observing stellar occultation and detecting radio signals; the former will in particular seek to detect molecules of water, oxygen and sulphuric compounds thought to be present in the atmosphere. The Virtis spectrometer will map the various layers of the atmosphere and conduct multi-wavelength cloud observation in order to provide images of atmospheric dynamics. Assisted by a magnetometer, the ASPERA 4 instrument will analyse interaction between the upper atmosphere and the solar wind in the absence of magnetospheric protection such as that surrounding the Earth (for Venus had no magnetic field). It will analyse the plasma generated by such interaction, while the magnetometer will study the magnetic field generated by the plasma. And the VMC camera will monitor the planet in four wavelengths, notably exploiting one of the "infrared windows" revealed in 1990 by the Galileo spacecraft (when flying by Venus en route for Jupiter), making it possible to penetrate cloud cover through to the surface. The camera will also be used to monitor atmospheric dynamics, notably to observe the double atmospheric vortex at the poles, the origin of which still remains a mystery.

Plans of lightning and airglow measurements with LAC/Akatsuki

NASA Astrophysics Data System (ADS)

Takahashi, Yukihiro; Hoshino, Naoya; Sato, Mitsuteru; Yair, Yoav; Galand, Marina; Fukuhara, Tetsuya

Though there are extensive researches on the existence of lightning discharge in Venus over few decades, this issue is still under controversial. Recently it is reported that the magnetometer on board Venus Express detected whistler mode waves whose source could be lightning discharge occurring well below the spacecraft. However, it is too early to determine the origin of these waves. On the other hand, night airglow is expected to provide essential information on the atmospheric circulation in the upper atmosphere of Venus. But the number of consecutive images of airglow obtained by spacecraft is limited and even the variations of most enhanced location is still unknown. In order to identify the discharge phenomena in the atmosphere of Venus separating from noises and to know the daily variation of airglow distribution in night-side disk, we plan to observe the lightning and airglow optical emissions with high-speed and high-sensitivity optical detector with narrow-band filters on board Akatsuki. We are ready to launch the flight model of lightning and airglow detector, LAC (Lightning and Airglow Camera). Main difference from other previous equipments which have provided evidences of lightning existence in Venus is the high-speed sampling rate at 32 us interval for each pixel, enabling us to distinguish the optical lightning flash from other pulsing noises. In this presentation the observation strategies, including ground-based support with optical telescopes, are shown and discussed.

Initial products of Akatsuki 1-μm camera

NASA Astrophysics Data System (ADS)

Iwagami, Naomoto; Sakanoi, Takeshi; Hashimoto, George L.; Sawai, Kenta; Ohtsuki, Shoko; Takagi, Seiko; Uemizu, Kazunori; Ueno, Munetaka; Kameda, Shingo; Murakami, Shin-ya; Nakamura, Masato; Ishii, Nobuaki; Abe, Takumi; Satoh, Takehiko; Imamura, Takeshi; Hirose, Chikako; Suzuki, Makoto; Hirata, Naru; Yamazaki, Atsushi; Sato, Takao M.; Yamada, Manabu; Yamamoto, Yukio; Fukuhara, Tetsuya; Ogohara, Kazunori; Ando, Hiroki; Sugiyama, Ko-ichiro; Kashimura, Hiroki; Kouyama, Toru

2018-01-01

The status and initial products of the 1-μm camera onboard the Akatsuki mission to Venus are presented. After the successful retrial of Venus' orbit insertion on Dec. 2015 (5 years after the failure in Dec. 2010), and after a long cruise under intense radiation, damage in the detector seems small and fortunately insignificant in the final quality of the images. More than 600 dayside images have been obtained since the beginning of regular operation on Apr. 2016 although nightside images are less numerous (about 150 in total at three wavelengths) due to the light scattered from the bright dayside. However, data acquisition stopped after December 07, 2016, due to malfunction of the electronics and has not been resumed since then. The 0.90-µm dayside images are of sufficient quality for the cloud-tracking procedure to retrieve wind field in the cloud region. The results appear to be similar to those reported by previous 1-μm imaging by Galileo and Venus Express. The representative altitude sampled for such dayside images is estimated to be 51-55 km. Also, the quality of the nightside 1.01-µm images is sufficient for a search for active volcanism, since interference due to cloud inhomogeneity appears to be insignificant. The quality of the 0.97-µm images may be insufficient to achieve the expected spatial resolution for the near-surface H2O mixing ratio retrievals.[Figure not available: see fulltext.

Analysis of Venusian Atmospheric Two-Dimensional Winds and Features Using Venus Express, Akatsuki, and Ground-Based Images

NASA Astrophysics Data System (ADS)

McCabe, Ryan M.; Gunnarson, Jacob; Sayanagi, Kunio M.; Blalock, John J.; Peralta, Javier; Gray, Candace L.; McGouldrick, Kevin; Imamura, Takeshi; Watanabe, Shigeto

2017-10-01

We investigate the horizontal dynamics of Venus’s atmosphere at cloud-top level. In particular, we focus on the atmospheric superrotation, in which the equatorial atmosphere rotates with a period of approximately 4-5 days (~60 times faster than the solid planet). The superrotation’s forcing and maintenance mechanisms remain to be explained. Temporal evolution of the zonal (latitudinal direction) wind could reveal the transport of energy and momentum in/out of the equatorial region, and eventually shed light on mechanisms that maintain the Venusian superrotation. As a first step, we characterize the zonal mean wind field of Venus between 2006 and 2013 in ultraviolet images captured by the Venus Monitoring Camera (VMC) on board the ESA Venus Express (VEX) spacecraft which observed Venus’s southern hemisphere. Our measurements show that, between 2006 and 2013, the westward wind speed at mid- to equatorial latitudes exhibit an increase of ~20 m/s; these results are consistent with previous studies by Kouyama et al. 2013 and Khatuntsev et al. 2013. The meridional component of the wind could additionally help us characterize large-scale cloud features and their evolution that may be connected to such superrotation. We also conduct ground-based observations contemporaneously with JAXA’s Akatsuki orbiter at the 3.5 m Astrophysical Research Consortium (ARC) telescope at the Apache Point Observatory (APO) in Sunspot, NM to extend our temporal coverage to present. Images we have captured at APO to date demonstrate that, even under unfavorable illumination, it is possible to see large features that could be used for large-scale feature tracking to be compared to images taken by Akatsuki. Our work has been supported by the following grants: NASA PATM NNX14AK07G, NASA MUREP NNX15AQ03A, NSF AAG 1212216, and JAXA’s ITYF Fellowship.Kouyama, T. et al (2013), J. Geophys. Res. Planets, 118, 37-46, doi:10.1029/2011JE004013.Khatuntsev et al. (2013), Icarus, 226, 140-158, doi:10.1016/j.icarus.2013.05.018

Ten Years of Observatory Science from Saanich Inlet on the VENUS Cabled Ocean Observatory

NASA Astrophysics Data System (ADS)

Dewey, R. K.; Tunnicliffe, V.; Macoun, P.; Round, A.

2016-02-01

The Saanich Inlet array of the VENUS cabled ocean observatory, maintained and operated by Ocean Networks Canada, was installed in February 2006, and in 2016 will have supported ten years of comprehensive interactive science. Representing the first in the present generation of cabled observing technologies, this coastal array has provided continuous high power and broadband communications to a variety of instrument platforms, hundreds of sensors, and enabled dozens of short, medium, and long-term studies. Saanich Inlet is a protected fjord with limited tidal action, resulting in an extremely productive environment, with strong seasonal chemical variations driven by episodic deep water renewal events and oxygen reduction processes. The breadth of the research has included microbial and benthic community dynamics, biogeochemical cycles, forensics, quantifying inter-annual variations, benthic-pelagic coupling, sensor testing, plankton dynamics, and bio-turbulence. Observatory measurements include core water properties (CTD & O2) and water-column echo-sounder records, as well as experiment-oriented deployments utilizing cameras, Gliders, Dopplers, hydrophones, and a variety of biogeochemical sensors. With a recently installed Buoy Profiler System for monitoring the entire water column, community plans continue with a dedicated Redox experiment through the 2016-17 seasons. Highlights from the dozens of research papers and theses will be presented to demonstrate the achievements enabled by a comprehensive coastal cabled observing system.

Chandra Captures Venus In A Whole New Light

NASA Astrophysics Data System (ADS)

2001-11-01

Scientists have captured the first X-ray view of Venus using NASA's Chandra X-ray Observatory. The observations provide new information about the atmosphere of Venus and open a new window for examining Earth's sister planet. Venus in X-rays looks similar to Venus in visible light, but there are important differences. The optically visible Venus is due to the reflection of sunlight and, for the relative positions of Venus, Earth and Sun during these observations, shows a uniform half-crescent that is brightest toward the middle. The X-ray Venus is slightly less than a half-crescent and brighter on the limbs. The differences are due to the processes by which Venus shines in visible and X-ray light. The X-rays from Venus are produced by fluorescence, rather than reflection. Solar X-rays bombard the atmosphere of Venus, knock electrons out of the inner parts of the atoms, and excite the atoms to a higher energy level. The atoms almost immediately return to their lower energy state with the emission of a fluorescent X-ray. A similar process involving ultraviolet light produces the visible light from fluorescent lamps. For Venus, most of the fluorescent X-rays come from oxygen and carbon atoms between 120 and 140 kilometers (74 to 87 miles) above the planet's surface. In contrast, the optical light is reflected from clouds at a height of 50 to 70 kilometers (31 to 43 miles). As a result, Venus' Sun-lit hemisphere appears surrounded by an almost-transparent luminous shell in X-rays. Venus looks brightest at the limb since more luminous material is there. Venus X-ray/Optical Composite of Venus Credit: Xray: NASA/CXC/MPE/K.Dennerl et al., Optical: Konrad Dennerl "This opens up the exciting possibility of using X-ray observations to study regions of the atmosphere of Venus that are difficult to investigate by other means," said Konrad Dennerl of the Max Planck Institute for Extraterrestrial Physics in Garching, Germany, leader of an international team of scientists that conducted the research. The Chandra observation of Venus was also a technological tour de force. The angular separation of Venus from the Sun, as seen from Earth, never exceeds 48 degrees. This relative proximity has prevented star trackers and cameras on other X-ray astronomy satellites from locking onto guide stars and pointing steadily in the direction of Venus to perform such an observation. Venus was observed on Jan. 10, 2001, with the Advanced CCD Imaging Spectrometer (ACIS) detector plus the Low Energy Transmission Grating and on Jan. 13, 2001, with the ACIS alone. Other members of the team were Vadim Burwitz and Jakob Engelhauser, Max Planck Institute; Carey Lisse, University of Maryland, College Park; and Scott Wolk, Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass. These results were presented at this week's "New Visions of X-ray universe in the XMM-Newton and Chandra Era" symposium in Noordwijk, Netherlands. The Low Energy Transmission Grating was built by the Space Research Organization of the Netherlands and the Max Planck Institute, and the ACIS instrument was developed for NASA by The Pennsylvania State University, University Park, and the Massachusetts Institute of Technology (MIT), Cambridge. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass.

The result of Venus Orbit Insertion of Akatsuki on December 7th, 2015

NASA Astrophysics Data System (ADS)

Sugiyama, K. I.; Nakamura, M.; Imamura, T.; Ishii, N.; Abe, T.; Kawakatsu, Y.; Hirose, C.; Satoh, T.; Suzuki, M.; Ueno, M.; Yamazaki, A.; Iwagami, N.; Watanabe, S.; Taguchi, M.; Fukuhara, T.; Takahashi, Y.; Yamada, M.; Imai, M.; Ohtsuki, S.; Uemizu, K.; Hashimoto, G. L.; Takagi, M.; Matsuda, Y.; Ogohara, K.; Sato, N.; Kasaba, Y.; Kouyama, T.; Hirata, N.; Nakamura, R.; Yamamoto, Y.; Horinouchi, T.; Yamamoto, M.; Hayashi, Y. Y.; Nakatsuka, J.; Kashimura, H.; Sakanoi, T.; Ando, H.; Murakami, S. Y.; Sato, T.; Takagi, S.; Nakajima, K.; Peralta, J.; Lee, Y. J.

2015-12-01

Japan launched Venus Climate Orbiter 'Akatsuki' (JAXA's mission code name: PLANET-C) to observe the dynamics of the Venus atmosphere globally and clarify the mechanism of the atmospheric circulation. The launch was on May 21st , 2010 from the Tanegashima Space Center. The cruise to Venus was smooth, however, the first Venus Orbit Insertion (VOI) trial on December 7th, 2010 tuned out to be a failure. Later Akatsuki has been orbiting the sun. Fortunately we keep the spacecraft in a healthy condition and surprisingly we have found another chance to let this spacecraft to meet Venus in 2015. Next VOI trial will be done on December 7th, 2015 and we report the result of this operation at this AGU meeting. This mission is planed to answer the question described below. The radius of the Earth and Venus are almost the same. In addition the radiation from the sun is also almost the same. The climates of these planets, however, are much different. For example, the strong zonal wind is observed on Venus with the period of 4 days, where Venus rotates westward with the period of 243 days. The wind speed is about 100 m s-1. This is called super rotation. We will investigate from data from Akatsuki what attributes to the difference of the climates between Earth and Venus. AKATSUKI was designed for remote sensing from an equatorial, elliptical orbit to tract the atmospheric motion at different altitudes using 5 cameras (3xIR, UV, Visible) and by the radio occultation technique. The first VOI has failed due to a malfunction of the propulsion system. The check valve between the helium tank and the fuel tank was blocked by an unexpected salt formation during the cruising from the Earth to Venus. As a result the main engine (orbital maneuvering engine, OME) became oxidizer-rich and fuel-poor condition, which led to an abnormal combustion in the engine with high temperature, and finally the engine was broken. We decide to use RCS thrusters for Trajectory Control Maneuvers' (TCMs) and finally insert Akatsuki into the orbit. Total thrust force of 4 RCS thrusters is 20 % of that of the main thruster and the orbit after VOI-R becomes a larger ellipse (apoapsis altitude will be finally 3.2x106km ) than the original plan in 2010. We have already done major 6 TCMs before July 31st, 2015 to let the spacecraft to meet Venus in December.

A planetary telescope at the ISS

NASA Astrophysics Data System (ADS)

Korablev, O.; Moroz, V.; Avanesov, G.; Rodin, V.; Bellucci, G.; Vid Machenko, A.; Tejfel, V.

We present the development of a 40-cm telescope to be deployed at the Russian segment of International Space Station (ISS) dedicated to the observations of planets of Solar system, which primary goal will be tracking climate-related changes and other variable phenomena on planets. The most effective will be the observations of Venus, Mars, Jupiter, Saturn, and comets, while other interesting targets will be certainly considered. This space-based observatory will perform monitoring of Solar System objects on regular basis The observatory includes the 40-cm narrow-field (f:20) telescope at a pointing platform with guidance system assuring pointing accuracy of ~10", and an internal tracking system with an accuracy inferior to 1" during tens of minutes. Four focal plane instruments, a camera, two spectrometers and a spectropolarimeter, will perform imaging and spectral observations in the range from ~200 nm to ~3 μm.

Magellan

NASA Technical Reports Server (NTRS)

1985-01-01

Of all the planets in the solar system, Venus is the most like our own Earth in size, mass, and distance from the Sun. The motions of our planetary "twin" were known to the ancients, and its apparent changes in shape, similar to the phases of the Moon, were first studied by Galileo more than four centuries ago. In the modern era, it is by far the most visited world in the solar system - more than 20 spacecraft from the Soviet Union and the United States have been sent there since the early 1960's. The clouds of Venus have been probed, the structure and composition of its atmosphere measured, its landscape photographed, and its rocks chemically analyzed by automated landers. Yet, for all our fascination with Venus, we have only a sketchy, general knowledge of the planet's surface. While the other three "terrestrial" worlds - Earth, Mercury, and Mars have long since been mapped, details of the face of Venus are still largely unknown, due to the planet's dense, constant cloud cover. The clouds prevent us from ever photographing the solid surface, even from space, with conventional cameras. Beginning in the early 1960s, scientists on Earth began to counter this problem by using radar waves, which, unlike visible light, are able to penetrate the Venusian clouds and reflect off the solid planet back to Earth. With the help of computer processing, these radar reflections can be turned into pictures of the Venus surface. Earth-based radar imaging is thus extremely valuable. but it also is limited-Venus always shows the same hemisphere to us when it is near enough in its orbit for high-resolution study, so only a fraction of the planet can be explored from Earth.

Search for ongoing volcanic activity on Venus: Case study of Maat Mons, Sapas Mons and Ozza Mons volcanoes

NASA Astrophysics Data System (ADS)

Shalygin, E. V.; Basilevsky, A. T.; Markiewicz, W. J.; Titov, D. V.; Kreslavsky, M. A.; Roatsch, Th.

2012-12-01

We report on attempts to find the ongoing volcanic activity from near-infrared night-time observations with the Venus Monitoring Camera (VMC) onboard of Venus Express. Here we consider VMC images of the areas of Maat Mons volcano and its vicinities, which, as it follows from analysis of the Magellan data, show evidence of geologically very recent volcanism. Analysis of VMC images taken in 12 observation sessions during the time period from 31 October 2007 to 15 June 2009 did not reveal any suspicious high-emission spots which could be signatures of the presently ongoing volcanic eruptions. We compare this time sequence of observations with the history of eruptions of volcano Mauna Loa, Hawaii, in the 20th century. This comparison shows that if Maat Mons volcano had the eruption history similar to that of Mauna Loa, the probability to observe an eruption in this VMC observation sequence would be about 8%, meaning that the absence of detection does not mean that Maat is not active in the present epoch. These estimates do not consider the effect of absorption and blurring of the thermal radiation coming from Venus surface by the planet atmosphere and clouds, which decreases detectability of thermal signature of fresh lavas. To assess the role of this effect we simulated near-infrared images of the study area with artificially added circular and rectangular (with different aspect ratios) lava flows having surface temperature 1000 K and various areas. These simulations showed that 1 km2 lava flows should be marginally seen by VMC. An increase of the lava surface area to 2-3 km2 makes them visible on the plains and increase of the area to 4-5 km2 makes them visible even in deep rift zones. Typical individual lava flows on Mauna Loa are a few km2, however, they often have been formed during weeks to months and the instantaneous size of the hot flow surface was usually much smaller. Thus the detection probability is significantly lower than 8%, but it is far from negligible. Our consideration suggests that further search of Maat Mons area and other areas including young rift zones makes sense and should be continued. More effective search could be done if observations simultaneously cover most part of the night side of Venus for relatively long (years) time of continuous observations.

Venus: Atmospheric motion and structure from Mariner 10 pictures

USGS Publications Warehouse

Murray, B.C.; Belton, M.J.S.; Danielson, G. Edward; Davies, M.E.; Gault, D.; Hapke, B.; O'Leary, B.; Strom, R.G.; Suomi, V.; Trask, N.

1974-01-01

The Mariner 10 television cameras imaged the planet Venus in the visible and near ultraviolet for a period of 8 days at resolutions ranging from 100 meters to 130 kilometers. The general pattern of the atmospheric circulation in the upper tropospheric/lower stratospheric region is displayed in the pictures. Atmospheric flow is symmetrical between north and south hemispheres. The equatorial motions are zonal (east-west) at approximately 100 meters per second, consistent with the previously inferred 4-day retrograde rotation. Angular velocity increases with latitude. The subsolar region, and the region downwind from it, show evidence of large-scale convection that persists in spite of the main zonal motion. Dynamical interaction between the zonal motion and the relatively stationary region of convection is evidenced by bowlike waves.

Remote-Raman spectroscopic study of minerals under supercritical CO2 relevant to Venus exploration.

PubMed

Sharma, Shiv K; Misra, Anupam K; Clegg, Samuel M; Barefield, James E; Wiens, Roger C; Acosta, Tayro E; Bates, David E

2011-10-01

The authors have utilized a recently developed compact Raman spectrometer equipped with an 85 mm focal length (f/1.8) Nikon camera lens and a custom mini-ICCD detector at the University of Hawaii for measuring remote Raman spectra of minerals under supercritical CO(2) (Venus chamber, ∼102 atm pressure and 423 K) excited with a pulsed 532 nm laser beam of 6 mJ/pulse and 10 Hz. These experiments demonstrate that by focusing a frequency-doubled 532 nm Nd:YAG pulsed laser beam with a 10× beam expander to a 1mm spot on minerals located at 2m inside a Venus chamber, it is possible to measure the remote Raman spectra of anhydrous sulfates, carbonates, and silicate minerals relevant to Venus exploration during daytime or nighttime with 10s integration time. The remote Raman spectra of gypsum, anhydrite, barite, dolomite and siderite contain fingerprint Raman lines along with the Fermi resonance doublet of CO(2). Raman spectra of gypsum revealed dehydration of the mineral with time under supercritical CO(2) at 423 K. Fingerprint Raman lines of olivine, diopside, wollastonite and α-quartz can easily be identified in the spectra of these respective minerals under supercritical CO(2). The results of the present study show that time-resolved remote Raman spectroscopy with a compact Raman spectrometer of moderate resolution equipped with a gated intensified CCD detector and low power laser source could be a potential tool for exploring Venus surface mineralogy both during daytime and nighttime from a lander. Copyright © 2011 Elsevier B.V. All rights reserved.

Mercury and Venus: Observing by Amateurs

NASA Astrophysics Data System (ADS)

Steele, R.; Murdin, P.

2003-04-01

MERCURY presents a solid surface at low resolution, while VENUS offers only a visually opaque but dynamic upper atmospheric layer for inspection. Past amateur study is largely the story of visual techniques applied with moderate instrumentation in order to build up a pictorial and descriptive record, but now amateurs use sophisticated techniques to monitor a broader spectral range and there is sco...

Aerosol properties in the upper clouds of Venus from glory observations by the Venus Monitoring Camera (Venus Express mission)

NASA Astrophysics Data System (ADS)

Markiewicz, Wojciech J.; Petrova, Elena V.; Shalygina, Oksana S.

2018-01-01

From the angular positions of the glory features observed on the upper cloud deck of Venus in three VMC channels (at 0.365, 0.513, and 0.965 μm), the dominating sizes of cloud particles and their refractive indices have been retrieved, and their spatial and temporal variations have been analyzed. For this, the phase profiles of brightness were compared to the single-scattering phase functions of particles of different sizes, since diffuse multiple scattering in the clouds does not move the angular positions of the glory, which is produced by the single scattering by cloud particles, but only makes them less pronounced. We presented the measured phase profiles in two ways: they were built for individual images and for individual small regions observed in series of successive images. The analysis of the data of both types has yielded consistent results. The presently retrieved radii of cloud particle average approximately 1.0-1.2 μm (though some values reach 1.4 μm) and demonstrate a variable pattern versus latitude and local solar time (LST). The decrease of particle sizes at high latitudes (down to 0.6 μm at 60°S) earlier found from the 0.965-μm and partly 0.365-μm data has been definitely confirmed in the analysis of the data of all three channels considered. To obtain the consistent estimates of particle sizes from the UV glory maximum and minimum positions, we have to vary the effective variance of the particle sizes, while it was fixed constant in our previous studies. The twofold increase of this parameter (from 0.07 to 0.14) diminishes the estimates of particle sizes by 10-15%, while the effect on the retrieved refractive index is negligible. The obtained estimates of the refractive index are more or less uniformly distributed over the covered latitude and LST ranges, and most of them are higher than those of concentrated sulfuric acid solution. This confirms our previous result obtained only at 0.965 μm, and now we may state that the cases of a relatively high real part of the refractive index are often observed for the 1-μm mode of cloud particles on Venus. Consequently, an additional component with a high value of the refractive index is required to be present in the cloud droplets. We suggest that this component is in small submicron particles; during the condensation process, they become incorporated into sulfuric acid droplets, which results in forming the complex UV absorbing particles with an increased refractive index. We suppose that this material can be ferric chloride that is one of the candidates for the so-called unknown UV absorber in the upper clouds of Venus.

Large stationary wave features appearing repeatedly at the cloud top of Venus

NASA Astrophysics Data System (ADS)

Kouyama, Toru; Imamura, Takeshi; Taguchi, Makoto; Fukuhara, Tetsuya; Sato, Takao M.; Hashimoto, George L.; Futaguchi, Masahiko; Takamura, Mao; Yamada, Takeru; Satoh, Takehiko; Nakamura, Masato; Akatsuki Science Team

2017-10-01

At the first observation sequence after Akatsuki’s Venus orbiter re-insertion (VOI-R) on December 7, 2015, Akatsuki revealed an existence of a large-scale “bow-shaped” feature staying at almost same geographic location (above Aphrodite Terra) at the cloud top level with the Longwave Infrared Camera (LIR) and Ultra Violet Imager (UVI). It expanded ~10,000 km from south to north and bended to downstream side of the super-rotation of Venus. A numerical calculation in Fukuhara et al. (2017) suggested that a gravity wave generated in the lower atmosphere can propagate upward to the cloud top and reproduce the observed bow-shape structure. Because the wave can transport momentum to the upper atmosphere which possibly decelerates the super-rotation, it is an interesting topic whether the stationary wave event is regular or just an occasional event. For more than three Venus years, or four Venus solar days, Akatsuki has observed huge stationary wave features in LIR images again and again since the VOI-R. It has been confirmed that four high-altitude regions, east and west part of Aphrodite Terra, Atra Regio, and Beta Regio, accompany with the large stationary features. All four regions are located in lower latitudes (< 30°), while no clear stationary feature has been confirmed above Maxwell Mountain, which is the highest mountain but located at a high latitude (60°), indicating geographical and latitudinal dependencies of the generation of the stationary waves. Akatsuki also reveals the stationary features can be considered as "daily" phenomena in Venus atmosphere. At every timing when the four high-altitude regions were passing afternoon region of Venus, huge stationary waves became clearer. On the other hand, when the high mountains were located around mid-night and morning, stationary features were much weaker than that in afternoon, or cannot be confirmed, indicating strong local time dependency of the appearance. Since lower latitude has more incident solar flux and afternoon area experiences longer solar heating than morning area, the geographical and the local time dependencies indicate that interaction between mountains and solar heating or solar fixed atmospheric structure may cause the large-scale features.

Solar System Portrait - Views of 6 Planets

NASA Image and Video Library

1996-09-13

These six narrow-angle color images were made from the first ever portrait of the solar system taken by NASA’s Voyager 1, which was more than 4 billion miles from Earth and about 32 degrees above the ecliptic. The spacecraft acquired a total of 60 frames for a mosaic of the solar system which shows six of the planets. Mercury is too close to the sun to be seen. Mars was not detectable by the Voyager cameras due to scattered sunlight in the optics, and Pluto was not included in the mosaic because of its small size and distance from the sun. These blown-up images, left to right and top to bottom are Venus, Earth, Jupiter, and Saturn, Uranus, Neptune. The background features in the images are artifacts resulting from the magnification. The images were taken through three color filters -- violet, blue and green -- and recombined to produce the color images. Jupiter and Saturn were resolved by the camera but Uranus and Neptune appear larger than they really are because of image smear due to spacecraft motion during the long (15 second) exposure times. Earth appears to be in a band of light because it coincidentally lies right in the center of the scattered light rays resulting from taking the image so close to the sun. Earth was a crescent only 0.12 pixels in size. Venus was 0.11 pixel in diameter. The planetary images were taken with the narrow-angle camera (1500 mm focal length). http://photojournal.jpl.nasa.gov/catalog/PIA00453

Concept study for a Venus Lander Mission to Analyze Atmospheric and Surface Composition

NASA Astrophysics Data System (ADS)

Kumar, K.; Banks, M. E.; Benecchi, S. D.; Bradley, B. K.; Budney, C. J.; Clark, G. B.; Corbin, B. A.; James, P. B.; O'Brien, R. C.; Rivera-Valentin, E. G.; Saltman, A.; Schmerr, N. C.; Seubert, C. R.; Siles, J. V.; Stickle, A. M.; Stockton, A. M.; Taylor, C.; Zanetti, M.; JPL Team X

2011-12-01

We present a concept-level study of a New Frontiers class, Venus lander mission that was developed during Session 1 of NASA's 2011 Planetary Science Summer School, hosted by Team X at JPL. Venus is often termed Earth's sister planet, yet they have evolved in strikingly different ways. Venus' surface and atmosphere dynamics, and their complex interaction are poorly constrained. A lander mission to Venus would enable us to address a multitude of outstanding questions regarding the geological evolution of the Venusian atmosphere and crust. Our proposed mission concept, VenUs Lander for Composition ANalysis (VULCAN), is a two-component mission, consisting of a lander and a carrier spacecraft functioning as relay to transmit data to Earth. The total mission duration is 150 days, with primary science obtained during a 1-hour descent through the atmosphere and a 2-hour residence on the Venusian surface. In the atmosphere, the lander will provide new data on atmospheric evolution by measuring dominant and trace gas abundances, light stable isotopes, and noble gas isotopes with a neutral mass spectrometer. It will make important meteorological observations of mid-lower atmospheric dynamics with pressure and temperature sensors and obtain unprecedented, detailed imagery of surface geomorphology and properties with a descent Near-IR/VIS camera. A nepholometer will provide new constraints on the sizes of suspended particulate matter within the lower atmosphere. On the surface, the lander will quantitatively investigate the chemical and mineralogical evolution of the Venusian crust with a LIBS-Raman spectrometer. Planetary differentiation processes recorded in heavy elements will be evaluated using a gamma-ray spectrometer. The lander will also provide the first stereo images for evaluating the geomorphologic/volcanic evolution of the Venusian surface, as well as panoramic views of the sample site using multiple filters, and detailed images of unconsolidated material and rock textures from a microscopic imager. Our mission proposal will enable the construction of a unique Venus test facility that will attract a new generation of scientists to Venus science. With emphasis on flight heritage, we demonstrate our cost basis and risk mitigation strategies to ensure that the VULCAN mission can be conducted within the requirements and constraints of the New Frontiers Program.

Observation of planets by a circumpolar stratospheric telescope

NASA Astrophysics Data System (ADS)

Yamamoto, M.; Taguchi, M.; Yoshida, K.; Sakamoto, Y.; Nakano, T.; Shoji, Y.; Takahashi, Y.; Hamamoto, K.; Nakamoto, J.; Imai, M.

2012-12-01

Phenomena in the planetary atmospheres and plasmaspheres have been studied by various methods using emissions emitted from there in the spectral regions from radio wave to X-ray. Optical observation of a planet has been performed by a ground-based telescope, a satellite telescope and an orbiter. A balloon-borne telescope is proposed as another platform for optical remote sensing of planets. Since it is floated in the stratosphere at an altitude of about 32 km, fine weather condition, excellent seeing and high transmittance of the atmosphere in the near ultraviolet and infrared regions are expected. Especially a planet can be continuously monitored by a long-period circumpolar flight. For these reasons we have been developing a balloon-borne telescope system for planetary observations from the polar stratosphere. In this system a Schmidt-Cassegrain telescope with a 300-mm clear aperture is mounted on a gondola whose attitude is controlled by control moment gyros, an active decoupling motor, and attitude sensors. The gondola can float in the stratosphere for periods longer than 1 week. Pointing stability of 0.1"rms will be achieved by the cooperative operation of the following three-stage pointing devices: a gondola-attitude control system, two axis telescope gimbals for coarse guiding, and a tip/tilt mirror mount for guiding error correction. The optical path is divided to three paths to an ultraviolet camera, an infrared camera and a position-sensitive photomultiplier tube for detection of guiding error. The size of gondola is 1 m by 1 m by 2.7 m high, and the weight is 784 kg including the weight of ballast of 300 kg. The first experiment of the balloon-borne telescope system was conducted on June 3, 2009 at Taikicho, Hokkaido targeting Venus. However, it failed due to a trouble in an onboard computer. The balloon-borne telescope was redesigned for the second experiment in August in 2012, when the target planet is also Venus. In the presentation, the balloon-borne telescope system, the ground-test results of its pointing performance and the results of balloon experiment in 2012 will be reported. Overview of the gondola ;

Exploring the interior of Venus with seismic and infrasonic techniques

NASA Astrophysics Data System (ADS)

Jackson, J. M.; Cutts, J. A.; Pauken, M.; Komjathy, A.; Smrekar, S. E.; Kedar, S.; Mimoun, D.; Garcia, R.; Schubert, G.; Lebonnois, S.; Stevenson, D. J.; Lognonne, P. H.; Zhan, Z.; Ko, J. Y. T.; Tsai, V. C.

2016-12-01

The dense atmosphere of Venus, which efficiently couples seismic energy into the atmosphere as infrasonic waves, enables an alternative to conventional seismology: detection of infrasonic waves in the upper atmosphere using either high altitude balloons or orbiting spacecraft. Infrasonic techniques for probing the interior of Venus can be implemented without exposing sensors to the severe surface environments on Venus. This approach takes advantage of the fact that approximately sixty-times the energy from a seismic event on Venus is coupled into the atmosphere on Venus as would occur for a comparable event on Earth. The direct or epicentral wave propagates vertically above the event, and the indirect wave propagates through the planet as a Rayleigh wave and then couples to an infrasonic wave. Although there is abundant evidence of tectonic activity on Venus, questions remain as to whether the planet is still active and whether energy releases are seismic or aseismic. In recent years, seismologists have developed techniques for probing crustal and interior structure in parts of the Earth where there are very few quakes. We have begun an effort to determine if this is also possible for Venus. Just as seismic energy propagates more efficiently upward across the surface atmosphere interface, equally acoustic energy originating in the atmosphere will propagate downwards more effectively. Measurements from a balloon platform in the atmosphere of Venus could assess the nature and spectral content of such sources, while having the ability to identify and discriminate signatures from volcanic events, storm activity, and meteor impacts. We will discuss our ongoing assessment on the feasibility of a balloon acoustic monitoring system. In particular, we will highlight our results of the flight experiment on Earth that will focus on using barometer instruments on a tethered helium-filled balloon in the vicinity of a known seismic source generated by a seismic hammer. Implications for conducting such measurements on Venus, including seismic and aseismic energy sources and propagation through its atmosphere, will also be discussed.

Monitoring Endeavour vent field deep-sea ecosystem dynamics through NEPTUNE Canada seafloor observatory

NASA Astrophysics Data System (ADS)

Matabos, M.; NC Endeavour Science Team

2010-12-01

Mid-ocean ridges are dynamic systems where the complex linkages between geological, biological, chemical, and physical processes are not yet well understood. Indeed, the poor accessibility to the marine environment has greatly limited our understanding of deep-sea ecosystems. Undersea cabled observatories offer the power and bandwidth required to conduct long-term and high-resolution time-series observations of the seafloor. Investigations of mid-ocean ridge hydrothermal ecosystem require interdisciplinary studies to better understand the dynamics of vent communities and the physico-chemical forces that influence them. NEPTUNE Canada (NC) regional observatory is located in the Northeast Pacific, off Vancouver Island (BC, Canada), and spans ecological environments from the beach to the abyss. In September-October 2010, NC will be instrumenting its 5th node, including deployment of a multi-disciplinary suite of instruments in two vent fields on the Endeavour Segment of the Juan de Fuca Ridge. These include a digital camera, an imaging sonar for vent plumes and flow characteristics (i.e. COVIS), temperature resistivity probes, a water sampler and seismometers. In 2011, the TEMPO-mini, a new custom-designed camera and sensor package created by IFREMER for real-time monitoring of hydrothermal faunal assemblages and their ecosystems (Sarrazin et al. 2007), and a microbial incubator, will added to the network in the Main Endeavour and Mothra vent fields. This multidisciplinary approach will involve a scientific community from different institutions and countries. Significant experience aids in this installation. For example, video systems connected to VENUS and NC have led to the development of new experimental protocols for time-series observations using seafloor cameras, including sampling design, camera calibration and image analysis methodologies (see communication by Aron et al. and Robert et al.). Similarly, autonomous deployment of many of the planned instruments has informed their adoption to the cabled instrument array at the Endeavour hydrothermal vents. This provides a unique laboratory for researchers to conduct long-term, integrated studies of hydrothermal vent ecosystem dynamics in relation to environmental variability at different temporal scales. In addition to programmed time-series monitoring, the NC infrastructure will also permit manual and automated modification of observational protocols in response to natural events. This will enhance our ability to document how the entire ecosystem reacts to potentially critical but short-lived environmental forces (e.g. seismic events). Sarrazin et al 2007. TEMPO: a new ecological module for studying deep-sea community dynamics at hydrothermal vents. OCEANS’07 IEEE Aberdeen Conference Proceedings

Simon Newcomb, America’s First Great Astronomer

DTIC Science & Technology

2009-02-01

1874 and 1882 transits of Venus across the Sun. A heliostat tracked the Sun and reflected its light through a fixed telescope, where the image was...a new and unique camera consisting of a heliostat , long-focal-length telescope, and photographic plate assembly5 (see figures 2 and 3). While the...and relays or solenoids qualified as leading- Remote mirror Objective lenses Rotating mirrorFixed mirror Observer’s eyepiece Adjustable slit Heliostat

Transit Observations of Venus's Atmosphere in 2012 from Terrestrial and Space Telescopes as Exoplanet Analogs

NASA Astrophysics Data System (ADS)

Pasachoff, Jay M.; Schneider, G.; Babcock, B. A.; Lu, M.; Penn, M. J.; Jaeggli, S. A.; Galayda, E.; Reardon, K. P.; Widemann, T.; Tanga, P.; Ehrenreich, D.; Vidal-Madjar, A.; Nicholson, P. D.; Dantowitz, R.

2013-06-01

We extensively observed the 8 June 2012 transit of Venus from several sites on Earth; we provide this interim status report about this and about two subsequent ToVs observed from space. From Haleakala Obs., we observed the entire June transit over almost 7 h with a coronagraph of the Venus Twilight Experiment B filter) and with a RED Epic camera to compare with simultaneous data from ESA's Venus Express, to study the Cytherean mesosphere; from Kitt Peak, we have near-IR spectropolarimetry at 1.6 µm from the aureole and during the disk crossing that compare well with carbon dioxide spectral models; from Sac Peak/IBIS we have high-resolution imaging of the Cytherean aureole for 22 min, starting even before 1st contact; from Big Bear, we have high-resolution imaging of Venus's atmosphere and the black-drop effect through 2nd contact; and we had 8 other coronagraphs around the world. For the Sept 21 ToV as seen from Jupiter, we had 14 orbits of HST to use Jupiter's clouds as a reflecting surface to search for an 0.01% diminution in light and a differential drop that would result from Venus's atmosphere by observing in both IR/UV, for which we have 170 HST exposures. As of this writing, preliminary data reduction indicates that variations in Jovian clouds and the two periods of Jupiter's rotation will be too great to allow extraction of the transit signal. For the December 20 ToV as seen from Saturn, we had 22 hours of observing time with VIMS on Cassini, for which we are looking for a signal of the 10-hr transit in total solar irradiance and of Venus's atmosphere in IR as an exoplanet-transit analog. Our Maui & Sac Peak expedition was sponsored by National Geographic Society's Committee for Research and Exploration; HST data reduction by NASA: HST-GO-13067. Some of the funds for the carbon dioxide filter for Sac Peak provided by NASA through AAS's Small Research Grant Program. We thank Rob Ratkowski of Haleakala Amateur Astronomers; Rob Lucas, Aram Friedman, Eric Pilger, Stan Truitt, and Steve Bisque/Software Bisque for Haleakala support/operations; Vasyl Yurchyshyn and Joseph Gangestad '06 of The Aerospace Corp. at Big Bear Solar Obs; LMSAL and Hinode science/operations team.

Long-term variations in abundance and distribution of sulfuric acid vapor in the Venus atmosphere inferred from Pioneer Venus and Magellan radio occultation studies

NASA Technical Reports Server (NTRS)

Jenkins, J. M.; Steffes, P. G.

1992-01-01

Radio occultation experiments have been used to study various properties of planetary atmospheres, including pressure and temperature profiles, and the abundance profiles of absorbing constituents in those planetary atmospheres. However, the reduction of amplitude data from such experiments to determine abundance profiles requires the application of the inverse Abel transform (IAT) and numerical differentiation of experimental data. These two operations preferentially amplify measurement errors above the true signal underlying the data. A new technique for processing radio occultation data has been developed that greatly reduces the errors in the derived absorptivity and abundance profiles. This technique has been applied to datasets acquired from Pioneer Venus Orbiter radio occultation studies and more recently to experiments conducted with the Magellan spacecraft. While primarily designed for radar studies of the Venus surface, the high radiated power (EIRP) from the Magellan spacecraft makes it an ideal transmitter for measuring the refractivity and absorptivity of the Venus atmosphere by such experiments. The longevity of the Pioneer Venus Orbiter has made it possible to study long-term changes in the abundance and distribution of sulfuric acid vapor, H2SO4(g), in the Venus atmosphere between 1979 and 1992. The abundance of H2SO4(g) can be inferred from vertical profiles of 13-cm absorptivity profiles retrieved from radio occultation experiments. Data from 1979 and 1986-87 suggest that the abundance of H2SO4(g) at latitudes northward of 70 deg decreased over this time period. This change may be due to a period of active volcanism in the late 1970s followed by a relative quiescent period, or some other dynamic process in the Venus atmosphere. While the cause is not certain, such changes must be incorporated into dynamic models of the Venus atmosphere. Potentially, the Magellan spacecraft will extend the results of Pioneer Venus Orbiter and allow the continued monitoring of the abundance of distribution of H2SO4(g) in the Venus atmosphere, as well as other interesting atmospheric properties. Without such measurements it will be difficult to address other issues such as the short-term spatial variability of the abundance of H2SO4(g) at similar latitudes in Venus atmosphere, and the identities of particles responsible for large-scale variations observed in NIR images.

Reduction and analysis of seasons 15 and 16 (1991 - 1992) Pioneer Venus radio occultation data and correlative studies with observations of the near-infrared emission of Venus

NASA Technical Reports Server (NTRS)

Jenkins, Jon M.

1992-01-01

Radio occultation experiments, and radio astronomical observations have suggested that significant variations (both spatial and temporal) in the abundances of sulfur-bearing gases are occurring below the Venus cloud layers. In addition, recent Near Infra-Red images of the nightside of Venus revealed large-scale features which sustain their shape over multiple rotations (the rotation periods of the features are 6.0 +/- 0.5 days). Presumably, the contrast variations in the NIR images are caused by variations in the abundance of large particles in the cloud deck. If these particles are composed of liquid sulfuric acid, one would expect a strong anticorrelation between regions with a high abundance of sulfuric acid vapor, and regions where there are large particles. One technique for monitoring the abundance and distribution of sulfuric acid vapor (H2SO4) at and below the main Venus cloud layer (altitudes below 50 km) is to measure the 13-cm wavelength opacity using Pioneer Venus Orbiter Radio Occultation Studies (PV-ORO). We are working to characterize variations in the abundance and distribution of subcloud H2SO4(g) in the Venus atmosphere by using a number of 13-cm radio occultation measurements conducted with the Pioneer Venus Orbiter near the inferior conjunction of 1991. When retrieved, the vertical profiles of the abundance of H2SO4(g) will be compared and correlated with NIR images of the night side of Venus made during the same period of time. Hopefully, the combination of these two different types of data will make it possible to constrain or identify the composition of the large particles causing the features observed in the NIR images. Considered on their own, however, the parameters retrieved from the radio occultation experiments are valuable science products.

Dynamics of the Venus upper atmosphere: Outstanding problems and new constraints expected from Venus Express

NASA Astrophysics Data System (ADS)

Bougher, S. W.; Rafkin, S.; Drossart, P.

2006-11-01

A consistent picture of the dynamics of the Venus upper atmosphere from ˜90 to 200 km has begun to emerge [e.g., Bougher, S.W., Alexander, M.J., Mayr, H.G., 1997. Upper Atmosphere Dynamics: Global Circulation and Gravity Waves. Venus II, CH. 2.4. University of Arizona Press, Tucson, pp. 259-292; Lellouch, E., Clancy, T., Crisp, D., Kliore, A., Titov, D., Bougher, S.W., 1997. Monitoring of Mesospheric Structure and Dynamics. Venus II, CH. 3.1. University of Arizona Press, Tucson, pp. 295-324]. The large-scale circulation of the Venus upper atmosphere (upper mesosphere and thermosphere) can be decomposed into two distinct flow patterns: (1) a relatively stable subsolar-to-antisolar (SS-AS) circulation cell driven by solar heating, and (2) a highly variable retrograde superrotating zonal (RSZ) flow. Wave-like perturbations have also been observed. However, the processes responsible for maintaining (and driving variations in) these SS-AS and RSZ winds are not well understood. Variations in winds are thought to result from gravity wave breaking and subsequent momentum and energy deposition in the upper atmosphere [Alexander, M.J., 1992. A mechanism for the Venus thermospheric superrotation. Geophys. Res. Lett. 19, 2207-2210; Zhang, S., Bougher, S.W., Alexander, M.J., 1996. The impact of gravity waves on the Venus thermosphere and O2 IR nightglow. J. Geophys. Res. 101, 23195-23205]. However, existing data sets are limited in their spatial and temporal coverage, thereby restricting our understanding of these changing circulation patterns. One of the major goals of the Venus Express (VEX) mission is focused upon increasing our understanding of the circulation and dynamical processes of the Venus atmosphere up to the exobase [Titov, D.V., Lellouch, E., Taylor, F.W., 2001. Venus Express: Response to ESA's call for ideas for the re-use of the Mars Express platform. Proposal to European Space Agency, 1-74]. Several VEX instruments are slated to obtain remote measurements (2006-2008) that will complement those obtained earlier by the Pioneer Venus Orbiter (PVO) between 1978 and 1992. These VEX measurements will provide a more comprehensive investigation of the Venus upper atmosphere (90-200 km) structure and dynamics over another period in the solar cycle and for variable lower atmosphere conditions. An expanded climatology of Venus upper atmosphere structure and wind components will be developed. In addition, gravity wave parameters above the cloud tops will be measured (or inferred), and used to constrain gravity wave breaking models. In this manner, the gravity wave breaking mechanism (thought to regulate highly variable RSZ winds) can be tested using Venus general circulation models (GCMs).

Equatorial jet in the lower to middle cloud layer of Venus revealed by Akatsuki

NASA Astrophysics Data System (ADS)

Horinouchi, Takeshi; Murakami, Shin-Ya; Satoh, Takehiko; Peralta, Javier; Ogohara, Kazunori; Kouyama, Toru; Imamura, Takeshi; Kashimura, Hiroki; Limaye, Sanjay S.; McGouldrick, Kevin; Nakamura, Masato; Sato, Takao M.; Sugiyama, Ko-Ichiro; Takagi, Masahiro; Watanabe, Shigeto; Yamada, Manabu; Yamazaki, Atsushi; Young, Eliot F.

2017-09-01

The Venusian atmosphere is in a state of superrotation where prevailing westward winds move much faster than the planet's rotation. Venus is covered with thick clouds that extend from about 45 to 70 km altitude, but thermal radiation emitted from the lower atmosphere and the surface on the planet's nightside escapes to space at narrow spectral windows of the near-infrared. The radiation can be used to estimate winds by tracking the silhouettes of clouds in the lower and middle cloud regions below about 57 km in altitude. Estimates of wind speeds have ranged from 50 to 70 m s-1 at low to mid-latitudes, either nearly constant across latitudes or with winds peaking at mid-latitudes. Here we report the detection of winds at low latitude exceeding 80 m s-1 using IR2 camera images from the Akatsuki orbiter taken during July and August 2016. The angular speed around the planetary rotation axis peaks near the equator, which we suggest is consistent with an equatorial jet, a feature that has not been observed previously in the Venusian atmosphere. The mechanism producing the jet remains unclear. Our observations reveal variability in the zonal flow in the lower and middle cloud region that may provide clues to the dynamics of Venus's atmospheric superrotation.

Equatorial jet in the lower to middle cloud layer of Venus revealed by Akatsuki.

PubMed

Horinouchi, Takeshi; Murakami, Shin-Ya; Satoh, Takehiko; Peralta, Javier; Ogohara, Kazunori; Kouyama, Toru; Imamura, Takeshi; Kashimura, Hiroki; Limaye, Sanjay S; McGouldrick, Kevin; Nakamura, Masato; Sato, Takao M; Sugiyama, Ko-Ichiro; Takagi, Masahiro; Watanabe, Shigeto; Yamada, Manabu; Yamazaki, Atsushi; Young, Eliot F

2017-01-01

The Venusian atmosphere is in a state of superrotation where prevailing westward winds move much faster than the planet's rotation. Venus is covered with thick clouds that extend from about 45 to 70 km altitude, but thermal radiation emitted from the lower atmosphere and the surface on the planet's night-side escapes to space at narrow spectral windows of near-infrared. The radiation can be used to estimate winds by tracking the silhouettes of clouds in the lower and middle cloud regions below about 57 km in altitude. Estimates of wind speeds have ranged from 50 to 70 m/s at low- to mid-latitudes, either nearly constant across latitudes or with winds peaking at mid-latitudes. Here we report the detection of winds at low latitude exceeding 80 m/s using IR2 camera images from the Akatsuki orbiter taken during July and August 2016. The angular speed around the planetary rotation axis peaks near the equator, which we suggest is consistent with an equatorial jet, a feature that has not been observed previously in the Venusian atmosphere. The mechanism producing the jet remains unclear. Our observations reveal variability in the zonal flow in the lower and middle cloud region that may provide new challenges and clues to the dynamics of Venus's atmospheric superrotation.

Europe Scores New Planetary Success: Venus Express Enters Orbit around the Hothouse Planet

NASA Astrophysics Data System (ADS)

2006-04-01

During the next four weeks, the Venus Express probe will perform a series of manoeuvres to reach the scheduled operational orbit for its scientific mission. It will move from its current highly elongated 9-day orbit to a 24-hour polar orbit, culminating at 66,000 km. From this vantage point, the orbiter will conduct an in-depth observation of the structure, chemistry and dynamics of the atmosphere of Venus for at least two Venusian days (486 Earth days). Enigmatic atmosphere From previous missions to Venus as well as observations directly from Earth, we already know that our neighbouring planet is shrouded in a thick atmosphere where extremes of temperature and pressure conditions are common. This atmosphere creates a greenhouse effect of tremendous proportions as it spins around the planet in four days in an unexplained “super-rotation” phenomenon. The mission of Venus Express will be to carry out a detailed characterisation of this atmosphere, using state-of-the-art sensors in order to answer the questions and solve the mysteries left behind by the first wave of explorers. It will also be the first Venus orbiter to conduct optical observations of the surface through “visibility windows” discovered in the infrared spectrum.V The commissioning of the onboard scientific instruments will begin shortly and the first raw data are expected within days. The overall science payload is planned to be fully operational within two months. Europe explores the Solar System With this latest success, ESA is adding another celestial body to its range of solar system studies. ESA also operates Mars Express around Mars, SMART-1 around the Moon and is NASA’s partner on the Cassini orbiter around Saturn. In addition, ESA is also operating the Rosetta probe en route to comet 67P/Churyumov-Gerasimenko. It should reach its target and become the first spacecraft ever to enter orbit around a comet nucleus by 2014. Meanwhile, ESA also plans to complete the survey of our celestial neighbours with the launch of the BepiColombo mission to Mercury in 2013. “With the arrival of Venus Express, ESA is the only space agency to have science operations under way around four planets: Venus, the Moon, Mars and Saturn” underlines Professor David Southwood, the Director of ESA’s science programmes. “We are really proud to deliver such a capability to the international science community.” “To better understand our own planet, we need to explore other worlds in particular those with an atmosphere,” said Jean-Jacques Dordain, ESA Director General. “We’ve been on Titan and we already are around Mars. By observing Venus and its complex atmospheric system, we will be able to better understand the mechanisms that steers the evolution of a large planetary atmosphere and the change of climates. In the end, it will help us to get better models of what is actually going on in our own atmosphere, for the benefit of all Earth citizens.” State-of-the-art science package Venus Express was developed for ESA by a European industrial team led by EADS Astrium incorporating 25 main contractors from 14 European countries. Its design is derived from that of its highly successful predecessor, Mars Express, and its payload accommodates seven instruments including upgraded versions of three instruments developed for Mars Express and two for Rosetta. The PFS spectrometer will determine the temperature and composition profile of the atmosphere at very high resolution. It will also monitor the surface temperature and search for hot spots from possible volcanic activity. The UV/infrared SpicaV/SOIR spectrometer and the VeRa radioscience experiment will probe the atmosphere by observing the occultation of distant starts or the fading of radio signals on the planetary limb. SpicaV/SOIR will be particularly looking for traces of water molecules, molecular oxygen and sulphur compounds, which are suspected to exist in the atmosphere of Venus. The Virtis spectrometer will map the different layers of the atmosphere and provide imagery of the cloud systems at multiple wavelengths to characterise the atmospheric dynamics. On the outer edge of the atmosphere, the Aspera instrument and a magnetometer will investigate the interaction with the solar wind and plasma it generates in an open environment without the protection of a magnetosphere like the one we have around Earth. The VMC wide-angle multi-channel camera will provide imagery in four wavelengths, including one of the “infrared windows”, which will make imaging of the surface possible through the cloud layer. It will provide global images and will assist in the identification of phenomena detected by the other instruments

New microwave spectrometer/imager has possible applications for pollution monitoring

NASA Technical Reports Server (NTRS)

Tooley, R. D.

1970-01-01

Microwave imager forms thermal-emissivity image of solid portion of planet Venus and provides data on the planet's atmosphere, surface, terminator, and temperature changes. These thermally produced multifrequency microwaves for image production of temperature profiles can be applied to water pollution monitoring, agriculture, and forestry survey.

Thermal zonal winds in the Venus mesosphere from the Venus Express temperature soundings

NASA Astrophysics Data System (ADS)

Piccialli, Arianna; Titov, Dmitri; Tellmann, Silvia; Migliorini, Alessandra; Read, Peter; Grassi, Davide; Paetzold, Martin; Haeusler, Bernd; Piccioni, Giuseppe; Drossart, Pierre

The Venus mesosphere (60-100 km altitude) is a transition region characterized by extremely complex dynamics: strong retrograde zonal winds dominate in the troposphere and lower meso-sphere while a solar-antisolar circulation can be observed in the upper mesosphere. The super-rotation extends from the surface up to the cloud top (˜65 km altitude) with wind speeds of only a few meters per second near the surface and reaching a maximum value of ˜100 m s-1 at cloud top, corresponding to a rotation period of ˜4 Earth days (˜60 times faster than Venus itself). The solar-antisolar circulation is driven by the day-night contrast in solar heating, and occurs above 110 km altitude with speeds of 120 m s-1 . The processes responsible for maintain-ing the zonal super-rotation in the lower atmosphere and its transition to the solar-antisolar circulation in the upper atmosphere are still poorly understood (Schubert et al.,2007). Different techniques have been used to obtain direct observations of wind at various altitudes: tracking of clouds in ultraviolet (UV) and near infrared (NIR) images give information on wind speeds at the cloud top (Moissl et al., 2009; Sanchez-Lavega et al., 2008) and within the clouds (˜47 km, ˜61 km) (Sanchez-Lavega et al., 2008) while ground-based measurements of Doppler shifts in the CO2 band at 10 µm (Sornig et al., 2008) and in several CO millimiter lines (Rengel et al., 2008) provide wind speeds above the clouds up to ˜110 km altitude. The deep atmosphere from the surface up to the cloud top has been investigated through the Doppler tracking of descent probes and balloons (Counselman et al., 1980; Kerzhanovich and Limaye, 1985). In the mesosphere, between 45-85 km of altitude, where direct observations of wind are not possible, the zonal wind field can be derived from the vertical temperature structure using a special approximation of the thermal wind equation: based on cyclostrophic balance. Previous studies (Leovy, 1973; Newman et al., 1984) showed that on a slowly rotating planet, like Venus, strong zonal winds at the cloud top can be described by a cyclostrophic balance in which the equatorward component of centrifugal force is balanced by the meridional pressure gradient. This equation gives a possibility to reconstruct the zonal wind if the temperature field is known, together with a suitable boundary condition on u. Two experiments onboard Venus Express are sounding the temperature structure of the Venus mesosphere: VIRTIS sounds the Venus Southern hemisphere in the altitude range 65-90 km with a very good spatial and temporal coverage (Grassi et al., 2008) and the Northern hemi-sphere but with more limited coverage; VeRa observes both northern and southern hemispheres between 40-90 km altitude with a vertical resolution of ˜500 m (Tellmann et al., 2008). Here we present zonal thermal winds derived applying cyclostrophic balance from VIRTIS and VeRa temperature retrievals. The main features of the retrieved winds are: (1) a midlatitude jet with a maximum speed up to 140 ± 15 m s-1 which occurs around 50° S latitude at 70 km altitude; (2) the fast decrease of the wind speed from 60° S toward the pole; (3) the decrease of the wind speed with increasing height above the jet (Piccialli et al., 2008). Cyclostrophic winds show satisfactory agreement with the cloud-tracked winds derived from the Venus Monitoring Camera (VMC/VEx) UV images, although a disagreement is observed at the equator and near the pole due to the breakdown of the cyclostrophic approximation. From zonal thermal winds the Richardson number has been evaluated. In good agreement with previous studies (Allison et al., 1994), we have found that the atmosphere is dominated by convection from ˜45 km altitude up to the cloud top. A high value of Richardson number has been determined, cor-responding to the midlatitude jet and indicating a highly stable atmosphere. Verification of the necessary condition for barotropic instability implies that barotropic instability may occur on the poleward side of the midlatitude jet where planetary waves are expected to play an important role in the maintenance of the circulation.

Solar System Portrait - 60 Frame Mosaic

NASA Image and Video Library

1996-09-13

The cameras of Voyager 1 on Feb. 14, 1990, pointed back toward the sun and took a series of pictures of the sun and the planets, making the first ever portrait of our solar system as seen from the outside. In the course of taking this mosaic consisting of a total of 60 frames, Voyager 1 made several images of the inner solar system from a distance of approximately 4 billion miles and about 32 degrees above the ecliptic plane. Thirty-nine wide angle frames link together six of the planets of our solar system in this mosaic. Outermost Neptune is 30 times further from the sun than Earth. Our sun is seen as the bright object in the center of the circle of frames. The wide-angle image of the sun was taken with the camera's darkest filter (a methane absorption band) and the shortest possible exposure (5 thousandths of a second) to avoid saturating the camera's vidicon tube with scattered sunlight. The sun is not large as seen from Voyager, only about one-fortieth of the diameter as seen from Earth, but is still almost 8 million times brighter than the brightest star in Earth's sky, Sirius. The result of this great brightness is an image with multiple reflections from the optics in the camera. Wide-angle images surrounding the sun also show many artifacts attributable to scattered light in the optics. These were taken through the clear filter with one second exposures. The insets show the planets magnified many times. Narrow-angle images of Earth, Venus, Jupiter, Saturn, Uranus and Neptune were acquired as the spacecraft built the wide-angle mosaic. Jupiter is larger than a narrow-angle pixel and is clearly resolved, as is Saturn with its rings. Uranus and Neptune appear larger than they really are because of image smear due to spacecraft motion during the long (15 second) exposures. From Voyager's great distance Earth and Venus are mere points of light, less than the size of a picture element even in the narrow-angle camera. Earth was a crescent only 0.12 pixel in size. Coincidentally, Earth lies right in the center of one of the scattered light rays resulting from taking the image so close to the sun. http://photojournal.jpl.nasa.gov/catalog/PIA00451

Solar System Portrait - 60 Frame Mosaic

NASA Technical Reports Server (NTRS)

1990-01-01

The cameras of Voyager 1 on Feb. 14, 1990, pointed back toward the sun and took a series of pictures of the sun and the planets, making the first ever 'portrait' of our solar system as seen from the outside. In the course of taking this mosaic consisting of a total of 60 frames, Voyager 1 made several images of the inner solar system from a distance of approximately 4 billion miles and about 32 degrees above the ecliptic plane. Thirty-nine wide angle frames link together six of the planets of our solar system in this mosaic. Outermost Neptune is 30 times further from the sun than Earth. Our sun is seen as the bright object in the center of the circle of frames. The wide-angle image of the sun was taken with the camera's darkest filter (a methane absorption band) and the shortest possible exposure (5 thousandths of a second) to avoid saturating the camera's vidicon tube with scattered sunlight. The sun is not large as seen from Voyager, only about one-fortieth of the diameter as seen from Earth, but is still almost 8 million times brighter than the brightest star in Earth's sky, Sirius. The result of this great brightness is an image with multiple reflections from the optics in the camera. Wide-angle images surrounding the sun also show many artifacts attributable to scattered light in the optics. These were taken through the clear filter with one second exposures. The insets show the planets magnified many times. Narrow-angle images of Earth, Venus, Jupiter, Saturn, Uranus and Neptune were acquired as the spacecraft built the wide-angle mosaic. Jupiter is larger than a narrow-angle pixel and is clearly resolved, as is Saturn with its rings. Uranus and Neptune appear larger than they really are because of image smear due to spacecraft motion during the long (15 second) exposures. From Voyager's great distance Earth and Venus are mere points of light, less than the size of a picture element even in the narrow-angle camera. Earth was a crescent only 0.12 pixel in size. Coincidentally, Earth lies right in the center of one of the scattered light rays resulting from taking the image so close to the sun.

ESA's Venus Express to reach final destination

NASA Astrophysics Data System (ADS)

2006-04-01

First step: catching Venus To begin to explore our Earth’s hot and hazy sister planet, Venus Express must complete a critical first step, the most challenging one following launch. This involves a set of complex operations and manoeuvres that will inject the spacecraft into orbit. The Venus Orbit Insertion (VOI) manoeuvre allows the spacecraft to reduce its speed relative to Venus, so that it can be captured by the planet’s gravitation. The manoeuvre is a critical one which must proceed at precisely the right place and time. The VOI phase officially started on 4 April and will not be completed until 13 April. It is split into three main sub-phases. The first consists in preparing or initialising the spacecraft for the actual capture manoeuvre so as to avoid the risk of the spacecraft going into safe mode, should parameters unrelated to VOI go off-range. The capture manoeuvre itself consists of a main-engine burn lasting about 50 minutes on the morning of 11 April starting at 09:17 (Central European Summer Time). This is the second main VOI sub-phase. The final sub-phase will be restoring all spacecraft functions, notably resuming communications with Earth and uplinking the commands to be executed during the preliminary ‘capture’ orbit. Orbital capture is controlled by an automatic sequence of predefined commands, uploaded to the spacecraft four days prior to VOI. This sequence is the minimum set needed to perform the main-engine burn. All spacecraft operations are controlled and commanded by the ground control team located at ESA’s European Spacecraft Operations Centre (ESOC) in Darmstadt, Germany. Timeeline of major VOI events (some times subject to change) 4 Aprilacecraft transmitter connected to low gain antenna is switched on. During its interplanetary cruise and during the scientific part of the mission to come, Venus Express communicates with Earth by means of its two high gain antennas. However, during the orbit capture phase (11 April), these two antennas become unusable because of the spacecraft’s required orientation at that time. The low gain antenna, carrying a feeble but instantly recognisable signal, will be transmitting throughout all VOI manoeuvres. This will allow ground controllers to monitor the velocity change during the burn, using NASA’s Deep Space Network’s 70-metre antenna near Madrid, Spain. No other means of communication with the Earth is possible during the capture burn. 5 and 9 April, targeting control manoeuvres. Two time slots are available to adjust course if needed. Given the high accuracy of the course correction performed end of March, Venus Express is currently on the right trajectory for a successful capture into orbit and it is therefore unlikely that either of these two extra slots will be required. 10 to 11 April, final preparations for VOI manoeuvre. 24 to 12 hours before VOI, spacecraft controllers will command Venus Express into its final configuration for the burn. Over the final 12 hours, they will monitor its status, ready to deal with any contingencies requiring last-minute trajectory correction or any revising of the main-engine burn duration. 11 April, 08:03 (CEST), ‘slew’ manoeuvre. This manoeuvre lasts about half an hour and rotates Venus Express so that the main engine faces the direction of motion. Thanks to this, the burn will slow down (rather than accelerate) the spacecraft. 11 April, 09:17 (CEST), main-engine burn starts. A few minutes after firing of the spacecraft thrusters to make sure the propellant settles in the feed lines to the main engine, the latter will begin its 50-minute long burn, ending at 10:07. This thrust will reduce the initial velocity of 29 000 kilometres per hour (in relation to Venus) by 15 percent, allowing capture. Venus Express will settle into its preliminary, elongated nine-day orbit. On capture, it will be at about 120 million kilometres from the Earth and, at its nearest point, within 400 km of the surface of Venus. During the burn, at 09:45 (CEST), Venus Express will disappear behind the planet and will not be visible from Earth. This is known as its ‘occultation’ period. The spacecraft will re-emerge from behind Venus’s disc some ten minutes later. So, even with the low gain antenna’s signal, it will only be visible during the first half of the burn and the last six minutes. Receiving the spacecraft signal after the occultation period will be the first positive sign of successful orbit insertion. 11 April, h 11:13 (CEST), re-establish communication with Earth. At the end of the burn, Venus Express still has to perform a few automatic operations. These re-orient the solar panels towards the sun and one of the high gain antennas (the smaller High Gain Antenna 2) towards Earth. If everything goes as expected, at 11:13 the spacecraft should be able to establish its first communication link with ESA’s Cebreros ground station near Madrid. Over the next few hours, it will send much-awaited information about its state of health. Information about its actual trajectory will be available from ESOC’s flight dynamics team around 12:30 (CEST). 12 to 13 April 2006, full reactivation starts. During the 24 hours following orbital capture, time will be devoted to reactivating all spacecraft functions, including all internal monitoring capacity. By the morning of the 13th, the larger ‘High Gain Antenna 1, hitherto unused, will be oriented and fed by the transmitter to communicate with Earth. The two high gain antennas, located on different sides of the spacecraft, will be used alternately during the mission, to avoid exposure to the sun of critical equipment on the outside. Reaching final orbit A series of further manoeuvres and many more days will be required to settle Venus Express into its final orbit. The preliminary nine-day orbit is elliptical, ranging from 350 000 kilometres at its furthest point from the planet (apocentre) to less than 400 kilometres at its closest (pericentre). During this period, Venus Express will also have to perform seven burns (two with the main engine, five with its banks of thrusters) to gradually reduce the apocentre of the following orbits. Final orbit will be reached on 7 May after 16 loops around the planet. It will be a polar orbit, ranging from 66 000 to 250 kilometres from Venus and with a pericentre located at above latitude 80° North. On 22 April, Venus Express will start its in-orbit commissioning phase. Its instruments will be switched on one by one for detailed checking until 13 May, then operated all together or in groups. This allows simultaneous observation of phenomena to be tested, to be ready for the nominal science phase beginning on 4 June. Observations in capture orbit The preliminary nine-day polar orbit will be a great opportunity to perform scientific observations. These will proceed only if other critical operations of the spacecraft do not take priority, and in any case not before 30 hours after VOI. The first opportunity to gather scientific data will be on 12-13 April. During this preliminary orbit phase, the complete disc of Venus will be fully visible for the spacecraft’s imaging instruments, an opportunity that will not occur during the nominal mission, when the range of distances from the planet will be smaller. Such observations will mainly cover the southern hemisphere, which was inadequately studied on previous missions. In particular, the geometry of the capture orbit makes it possible to observe the dynamics of the Venusian atmosphere continuously and thoroughly from a greater distance, over a duration even longer than the full rotation cycle of the atmosphere at the cloud tops (the still-unexplained four-day ‘super rotation’). Indeed, atmospheric study is one of the mission’s prime goals. For instance, from distances greater than 200 000 kilometres, the visible/near-infrared mapping spectrometer (VIRTIS) will be able to take snapshots of the entire planetary disc and atmosphere. During the nominal science phase, images of the atmosphere will need to be built up in mosaics. The analyser of space plasma and energetic atoms (ASPERA) will have an unprecedented opportunity to study from great distances the unperturbed solar wind and to gather data on the atmospheric escape processes on a planet which has no magnetic protection. In the capture orbit, all the instruments (except the VeRA radio science experiment and PFS spectrometer) may perform observations for a few hours a day on selected dates. …and plenty of science to come Venus Express is designed to carry out scientific observations over two Venusian days, corresponding to 486 Earth days. The mission could be extended to double the nominal duration. Notwithstanding the intense previous exploration (Venus is the third most visited celestial body in our solar system after the Moon and Mars), a plethora of mysteries still surround this planet. Venus Express’s unique instruments for planetary investigation are tailored to taking advantage of clues from previous missions and investigating the planet’s oddities with unprecedented precision. The instruments onboard, the spacecraft’s ‘eyes’, include a combination of spectrometers (the PFS planetary fourier spectrometer and the SpicaV/SOIR ultraviolet and infrared atmospheric spectrometer), spectro-imagers (VIRTIS ultraviolet/visible/near-infrared mapping spectrometer) and imagers (VMC Venus monitoring Camera). They are extremely sensitive in a wide range of electromagnetic wavelengths from ultraviolet to infrared and will allow detailed study of the Venusian atmosphere and its interaction with the surface. Also onboard are the MAG magnetometer, the ASPERA analyser of space plasma & energetic atoms and the VeRA radio science experiment, to study all interaction between the atmosphere and the ever-blowing solar wind. Venus Express will take advantage, for the first time ever, of the so-called ‘infrared windows’, which are narrow atmospheric bands in the infrared part of the spectrum. Through these, precious information about the lower layers of the atmosphere and even the surface can be gathered. The Venus Express mission will help find answers to several unsolved questions. How does the complex atmospheric dynamics and cloud system work? What causes the fast “super-rotation” of the atmosphere at the cloud top? And what is the origin of the double vortex at the north pole? Venus Express will also investigate the processes that determine the chemistry of the noxious Venusian atmosphere, which can be as hot as 500°C at the surface and is mainly composed of carbon dioxide, with clouds of sulphuric acid drops. It will study what role the greatest greenhouse effect in the solar system plays in the overall evolution of the Venusian climate. It will also help us to ascertain whether Venus provides a possible preview of a future Earth. Lastly, through combined analysis of the dense atmosphere and surface, Venus Express will help us to understand the planet’s geology and ascertain there are signs of present volcanic or seismic activity. “Venus Express to ground control” During the course of the nominal mission, Venus Express will communicate with Earth via ESA’s Cebreros ground station near Madrid. ESA’s New Norcia station in Australia will be used to support the VeRA radio science experiment.

Daytime Utilization of a University Observatory for Laboratory Instruction

NASA Astrophysics Data System (ADS)

Mattox, J. R.

2006-08-01

Scheduling convenience provides a strong incentive to fully explore effective utilization of educational observatories during daylight hours. I present two compelling daytime student activities that I developed at the Observatory at Fayetteville State University. My Introductory Astronomy Laboratory classes pursue these as separate investigations. My Physical Science classes complete both in a single lab period of 110 minutes duration. Both of these activities are also appropriate for High School student investigators, and could be used as demonstrations for younger students. Daylight Observation of Venus. With a clear sky, and when its elongation exceeds ~20˚, Venus is readily apparent in the daytime sky once a telescope is pointed at it. This is accomplished either with a digital pointing system, or with setting circles on a polar-aligned mount using the Sun to initialize the RA circle. Using the telescope pointing as a reference, it is also possible under optimal circumstances for students to see Venus in the daytime sky with naked eyes. Students are asked to write about the circumstances that made it possible to see Venus. Educational utilization of daytime observations of the Moon, Jupiter, Saturn, and the brightest stars are also discussed. Using a CCD Camera to Determine the Temperature of a Sunspot. After my students view the Sun with Eclipse Glasses and in projection using a 3-inch refractor, they analyze a CCD image of a sunspot (which they obtain if possible) to determine the ratio of its surface intensity relative to the normal solar surface. They then use the Stefan-Boltzmann law (usually with some coaching) to determine the sunspot temperature given the nominal surface temperature of the Sun. Appropriate safety precautions are presented given the hazards of magnified sunlight. Mitigation of dome seeing during daylight hours is discussed.

Pissible Habitats in the Venusian Environment? How Can the Venus Payload Contribute?

NASA Astrophysics Data System (ADS)

Muller, C. L.; Schulze-Makuch, D.

2005-12-01

The Venusian conditions are unique in the solar system. Venus has a dense CO2 atmosphere, is volcanically active, and has plenty of energy sources such as light, UV radiation, volcanic activity, and chemical energy from atmospheric disequilibria conditions. Its surface conditions are sufficiently hot for sterilization and volcanism injects highly toxic gases which in the absence of unbound water can accumulate in the atmosphere. The Venusian surface is constantly regenerated by volcanism and any possible fossil record from early Venus history in which oceans existed on its surface is almost certainly destroyed. Its upper atmosphere lays bare to solar radiation with only carbon dioxide to act as a confirmed EUV filter. Any possibility of life was considered irrational before extremophile bacteria were discovered in dark undersea hot sulphur rich volcanic vents on Earth. However, some regions of the Venusian clouds might show conditions similar to the earth surface and could be a habitat of thermophilic microbial life similar to the one observed on Earth. A synergy between different instruments of the VENUS-Express payload, the SPICAV spectrometer and the VMC camera in a first step, and the spectrometers VIRTIS and PFS in a second step, will probe the actual environmental conditions of the cloud region. The SPICAV spectrometer, in particular, has three channels including, two infrared AOTF channels and could give access to organic signatures in both the UV and infrared. Given these observations we will be able to analyze whether the environmental conditions of the cloud layer would make it a possible habitat for extant microbial life. The instruments will shed answers to the availability of nutrients, water, types of energy sources, atmospheric dynamics, and organic chemistry.

Upgrading and testing program for narrow band high resolution planetary IR imaging spectrometer

NASA Technical Reports Server (NTRS)

Wattson, R. B.; Rappaport, S.

1977-01-01

An imaging spectrometer, intended primarily for observations of the outer planets, which utilizes an acoustically tuned optical filter (ATOF) and a charge coupled device (CCD) television camera was modified to improve spatial resolution and sensitivity. The upgraded instrument was a spatial resolving power of approximately 1 arc second, as defined by an f/7 beam at the CCD position and it has this resolution over the 50 arc second field of view. Less vignetting occurs and sensitivity is four times greater. The spectral resolution of 15 A over the wavelength interval 6500 A - 11,000 A is unchanged. Mechanical utility has been increased by the use of a honeycomb optical table, mechanically rigid yet adjustable optical component mounts, and a camera focus translation stage. The upgraded instrument was used to observe Venus and Saturn.

IUS with Magellan spacecraft drifts into space after STS-30 deployment

NASA Image and Video Library

1989-05-04

STS030-71-063 (4 May 1989) --- This scene is one of two released by NASA showing the process of solar array panel deployment on the Magellan spacecraft. Panels are not fully extended in this frame. The spacecraft had earlier been released by the STS-30 crewmembers to begin its long journey to the planet Venus for an extensive radar mapping mission. The frame was photographed through Atlantis? aft flight deck windows with a handheld 70mm camera. The complementary photograph is STS030-71-070.

Coordinating High-Resolution Traffic Cameras : Developing Intelligent, Collaborating Cameras for Transportation Security and Communications

DOT National Transportation Integrated Search

2015-08-01

Cameras are used prolifically to monitor transportation incidents, infrastructure, and congestion. Traditional camera systems often require human monitoring and only offer low-resolution video. Researchers for the Exploratory Advanced Research (EAR) ...

Long life testing of spare Mariner Venus '67 hardware. [power conditioning electronics

NASA Technical Reports Server (NTRS)

Silverman, S. W.

1976-01-01

The faultless performance of the Mariner Venus '67 Power Conditioning Electronics (PCE) throughout six years of continuous operation in a simulated space environment is reported. Weekly functional tests supplemented by daily monitoring verified that the PCE equipment can perform to its intended functions for at least six years without apparent performance degradation. Performance throughout the test period was very stable, there are no circuit or redundancy improvements to be considered. When the equipment was examined after the test was completed, there was no evidence of any physical damage nor any difficulty in disconnecting the wiring connectors.

Phenology cameras observing boreal ecosystems of Finland

NASA Astrophysics Data System (ADS)

Peltoniemi, Mikko; Böttcher, Kristin; Aurela, Mika; Kolari, Pasi; Tanis, Cemal Melih; Linkosalmi, Maiju; Loehr, John; Metsämäki, Sari; Nadir Arslan, Ali

2016-04-01

Cameras have become useful tools for monitoring seasonality of ecosystems. Low-cost cameras facilitate validation of other measurements and allow extracting some key ecological features and moments from image time series. We installed a network of phenology cameras at selected ecosystem research sites in Finland. Cameras were installed above, on the level, or/and below the canopies. Current network hosts cameras taking time lapse images in coniferous and deciduous forests as well as at open wetlands offering thus possibilities to monitor various phenological and time-associated events and elements. In this poster, we present our camera network and give examples of image series use for research. We will show results about the stability of camera derived color signals, and based on that discuss about the applicability of cameras in monitoring time-dependent phenomena. We will also present results from comparisons between camera-derived color signal time series and daily satellite-derived time series (NVDI, NDWI, and fractional snow cover) from the Moderate Resolution Imaging Spectrometer (MODIS) at selected spruce and pine forests and in a wetland. We will discuss the applicability of cameras in supporting phenological observations derived from satellites, by considering the possibility of cameras to monitor both above and below canopy phenology and snow.

Telescopes and recording systems used by amateurs for studying planets in our solar system - an overview

NASA Astrophysics Data System (ADS)

Kowollik, S.; Gaehrken, B.; Fiedler, M.; Gerstheimer, R.; Sohl, F.; Koschny, D.

2008-09-01

During the last couple of years, engaged amateur astronomers have benefited by the rapid development in the field of commercial CCD cameras, video techniques, and the availability of mirror telescopes with high quality. Until recently, such technical equipment and the related handling experience had been reserved to research institutes. This contribution presents the potential capabilities of amateur astronomers and describes the approach to the production of data. The quality of the used telescopes is described with respect to aperture and resolving power; as well as the quantum efficiency of the used sensitive b/w CCD cameras with respect to the detectable wavelength. Beyond these facts the necessary exposure times for CCD images using special filters are discussed. Today's amateur astronomers are able to image the bodies of the solar system in the wavelength range between 340 and 1050 nm [1], [2], [3], [4]. This covers a wide range of the spectrum which is investigated with cameras on board of space telescopes or planetary probes. While space probes usually obtain high-resolution images of individual Surface or atmospheric features of the planets, the images of amateur astronomers show the entire surface of the observed planet. Both datasets together permit a more comprehensive analysis of the data aquired in each case. The "Venus Amateur Observing Project" of the European Space Agency [5] is a first step into a successful co-operation between amateur astronomers and planetary scientists. Individual CCD images captured through the turbulent atmosphere of the Earth usually show characteristic distortions of the arriving wave fronts. If one captures hundreds or thousands of images on a video stream in very short time, there will be always also undistorted images within the data. Computer programmes are available to identify and retrieve these undistorted images and store them for further processing [7]. This method is called "Lucky Imaging" and it allows to achieve nearly the theoretical limit of telescopic resolution. By stacking the undistorted images, the signal-to-noise ratio of the data can be increased significantly. "Lucky Imaging" has become a standard in the amateur community since several years. Contrary to space based observations the data rate is not limited by the capacity of any radio transmission, but only limited by the scanning rate and capacity of a modern computer hard disk. An individual video with the uncompreesed raw data can be as large as 4 to 5 GB. EPSC Abstracts, Vol. 3, EPSC2008-A-00191, 2008 European Planetary Science Congress, Author(s) 2008 In addition to the video data, so-called meta data such as the observing location, the recording time, the used filter, environmental conditions (air temperature, wind velocity, air humidity and Seeing) are also documented. From these meta data, the central meridian (CM) of the observed planet during the time of image acqusition can be determined. After data reduction the resulting images can be used to produce map projections or position measurements of albedo structures on the planetary surface or of details within atmospheric features. Amateur astronomers can observe objects in the solar system for large continuous time periods due to the large number of the existing observers e. g. the members of the Association of Lunar & Planetary Observers [6] and their telescopes. They can and react very fast to special events, since they do not have to submit requests for telescope time to a national or international organization. References: [1] Venusimages in uv-light: B. Gährken: http://www.astrode.de/venus07.htm R. Gerstheimer: http://www.astromanie.de/astromania/galerie/venus/venus.html S. Kowollik: http://www.sternwarte-zollern-alb.de/mitarbeiterseiten/kowollik/venus M. Weigand: http://www.skytrip.de/venus2007.htm [2] Images of planets in visible light: M. Fiedler: http://bilder.astroclub-radebeul.de/kategorien.php?action=showukats&kat=0 R. Gerstheimer: http://www.astromanie.de/ S. Kowollik: http://www.sternwarte-zollern-alb.de/mitarbeiterseiten/kowollik [3] Images of planets in methane band light: S. Kowollik: http://www.sternwarte-zollern-alb.de/beobachtungen/methanband/index-gb.htm [4] Images of planets in ir-light: S. Kowollik: http://www.sternwarte-zollern-alb.de/beobachtungen/ir/index-gb.htm [5] ESA amateur astronomer observing campaign: http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=38833 http://www.rssd.esa.int/index.php?project=VENUS [6] Association of Lunar & Planetary Observation (ALPO): http://alpo-astronomy.org/ [7] Software: Cor Berrevoets (Registax): http://www.astronomie.be/registax/ Christian Buil (IRIS): http://www.astrosurf.com/buil/us/iris/iris.htm Georg Dittié (Giotto): http://www.videoastronomy.org/giotto.htm Grischa Hahn (WinJupos): http://www.grischa-hahn.homepage.t-online.de/astro/winjupos/index.htm

New generation of meteorology cameras

NASA Astrophysics Data System (ADS)

Janout, Petr; Blažek, Martin; Páta, Petr

2017-12-01

A new generation of the WILLIAM (WIde-field aLL-sky Image Analyzing Monitoring system) camera includes new features such as monitoring of rain and storm clouds during the day observation. Development of the new generation of weather monitoring cameras responds to the demand for monitoring of sudden weather changes. However, new WILLIAM cameras are ready to process acquired image data immediately, release warning against sudden torrential rains, and send it to user's cell phone and email. Actual weather conditions are determined from image data, and results of image processing are complemented by data from sensors of temperature, humidity, and atmospheric pressure. In this paper, we present the architecture, image data processing algorithms of mentioned monitoring camera and spatially-variant model of imaging system aberrations based on Zernike polynomials.

Ground-based observation of the cyclic nature and temporal variability of planetary-scale UV features at the Venus cloud top level

NASA Astrophysics Data System (ADS)

Imai, Masataka; Takahashi, Yukihiro; Watanabe, Makoto; Kouyama, Toru; Watanabe, Shigeto; Gouda, Shuhei; Gouda, Yuya

2016-11-01

A planetary-scale bright and dark UV feature, known as the ;Y-feature,; rotates around Venus with a period of 4-5 days and has been long-time interpreted as planetary waves. When assuming this, its rotation period and spatial structure might help to understand the propagation of the planetary-scale waves and find out their role in the acceleration-deceleration of the zonal wind speed, which is essential for understanding the super-rotation of the planet. The rotation period of the UV feature varied over the course of observation by the Pioneer Venus orbiter. However, in previous explorations of Venus such as Pioneer Venus and Venus Express, the spacecraft were operated in nearly fixed inertial space. As a result, the periodicity variations on sub-yearly timescales (one Venusian year is ∼224 Earth days) were obscured by the limitations of continuous dayside observations. We newly conducted six periods of ground-based Venus imaging observations at 365 nm from mid-August 2013 to the end of June 2014. Each observation period spanned over half or one month, enabling long-term monitoring of Venus' atmosphere above the equator region. Distributions of the relative brightness were obtained from the equatorial (EQ) to mid-latitudinal regions in both hemispheres, and from the cyclical variations of these distributions we deduced the rotation periods of the UV features of the cloud tops brightness. The relative brightness exhibited periods of 5.2 and 3.5 days above 90% of significance. The relative intensities of these two significant components also seemed subject to temporal variations. Although the 3.5-day component considered persists throughout the observation periods, its dominance over the longer period varied in a cyclic fashion. The prevailing first significant mode seems to change from 5.2-day waves to 3.5-day waves in about nine months, which is clearly inconsistent with the Venusian year. Clear periodic perturbations, indicating stability of the planetary-scale UV-feature, were observed only in the presence of single longer or shorter periodic waves. During the transition periods of dominant-wave changing, the amplitude of the relative brightness was largely changed. This can be explained by the deformation of the Y-shaped UV feature as observed by Pioneer Venus in 1979.

Mimicking the Moon

NASA Image and Video Library

2014-11-03

When Galileo first observed Venus displaying a crescent phase, he excitedly wrote to Kepler (in anagram) of Venus mimicking the moon-goddess. He would have been delirious with joy to see Saturn and Titan, seen in this image, doing the same thing. More than just pretty pictures, high-phase observations -- taken looking generally toward the Sun, as in this image -- are very powerful scientifically since the way atmospheres and rings transmit sunlight is often diagnostic of compositions and physical states. In this example, Titan's crescent nearly encircles its disk due to the small haze particles high in its atmosphere refracting the incoming light of the distant Sun. This view looks toward the sunlit side of the rings from about 3 degrees above the ringplane. The image was taken in violet light with the Cassini spacecraft wide-angle camera on Aug. 11, 2013. The view was obtained at a distance of approximately 1.1 million miles (1.7 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 154 degrees. Image scale is 64 miles (103 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA18291

Earth and Moon as viewed by Mariner 10

NASA Technical Reports Server (NTRS)

1973-01-01

Mariner 10 was launched on November 3, 1973, 12:45 am PST, from Cape Canaveral on an Atlas/Centaur rocket (a reconditioned Intercontinental Ballistic Missile - ICBM). Within 12 hours of launch the twin cameras were turned on and several hundred pictures of both the Earth and the Moon were acquired over the following days.

The Earth and Moon were imaged by Mariner 10 from 2.6 million km while completing the first ever Earth-Moon encounter by a spacecraft capable of returning high resolution digital color image data. These images have been combined at right to illustrate the relative sizes of the two bodies. From this particular viewpoint the Earth appears to be a water planet!

The Mariner 10 mission is managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, explored Venus in February 1974 on the way to three encounters with Mercury-in March and September 1974 and in March 1975. The spacecraft took more than 7,000 photos of Mercury, Venus, the Earth and the Moon.

Image Credit: NASA/JPL/Northwestern University

IUS with Magellan spacecraft drifts into space after STS-30 deployment

NASA Image and Video Library

1989-05-04

STS030-71-070 (4 May 1989) --- This scene is one of two released by NASA showing the process of solar array panel deployment on the Magellan spacecraft. Though partially blended into the backdrop of the blackness of space, it appears the two panels are fully extended in this frame. The spacecraft had earlier been released by the STS-30 crewmembers to begin its long journey to the planet Venus for an extensive radar mapping mission. The frame was photographed through Atlantis' aft flight deck windows with a handheld 70mm camera. The complementary photograph is STS030-71-063.

Pioneer Venus

NASA Technical Reports Server (NTRS)

Fimmel, Richard O.; Colin, Lawrence; Burgess, Eric

1983-01-01

Venus before Pioneer, the Pioneer Venus mission, Pioneer Venus spacecraft, scientific investigation, mission to Venus scientific results, and results of Soviet studies of Venus are addressed. A chronology of exploration of Venus from Earth before the Pioneer Venus mission and Venus nomenclature and mythology are provided.

Frank Ross's Early Direct Photographs of Venus and His Interpretation of Them

NASA Astrophysics Data System (ADS)

Osterbrock, Donald E.

2006-09-01

Frank Ross was an outstandingly creative astronomical "jack of many trades" (Monet) or "cat with nine astronomical lives". After joining the Yerkes Observatory faculty in 1924, at age 50, he took a long series of almost nightly direct photographs of Venus in 1927 with the Mount Wilson 60-inch and 100-inch reflectors as a guest observer. He published many of these images in the ApJ in 1928, with his conclusions on the nature of Venus. Ross discovered markings, seen only in the ultraviolet images, parallel "belts" indicating rotation. They changed rapidly. From these photographs he developed a tentative picture of a deep opaque atmosphere, with high pressure at the surface of the planet. The changes were due to "violent events" (winds or storms) in its atmosphere. From spectroscopic results of Slipher, Adams, StJohn, and Nicholson he took the rotation period to be long. But bolometric observations of Pettit, Nicholson, Coblentz, and Lampland, indicated little temperature change between the illuminated and dark parts of the disk, so it could not be too slow. Ross settled on a "compromise" rotation period of about 30 days based on the data he had. The spectroscopic measurements showed there was very little, if any, H2O or O2 in the atmosphere. Ross is best known today for his Ross wide-angle camera design, his Ross high-proper-motion stars, his Ross photometer, and his Ross correctors for large reflecting telescopes, but his foray into planetary astronomy, long before the era of radar or close-up imaging and spectroscopy from space vehicles, was an important first step toward understanding Venus. His years of experience in laboratory studies of the properties of photographic plates, developers, and mensuration were highly important for this work. Equally so were his cheerful, peppery personality and his close relations with many Mount Wilson and Lowell Observatory staff members.

Limb darkening in Venus night-side disk as viewed from Akatsuki IR2

NASA Astrophysics Data System (ADS)

Satoh, Takehiko; Nakakushi, Takashi; Sato, Takao M.; Hashimoto, George L.

2017-10-01

Night-side hemisphere of Venus exhibits dark and bright regions as a result of spatially inhomogeneous cloud opacity which is illuminated by infrared radiation from deeper atmosphere. The 2-μm camera (IR2) onboard Akatsuki, Japan's Venus Climate Orbiter, is equipped with three narrow-band filters (1.735, 2.26, and 2.32 μm) to image Venus night-side disk in well-known transparency windows of CO2 atmosphere (Allen and Crawford 1984). In general, a cloud feature appears brightest when it is in the disk center and becomes darker as the zenith angle of emergent light increases. Such limb darkening was observed with Galileo/NIMS and mathematically approximated (Carlson et al., 1993). Limb-darkening correction helps to identify branches, in a 1.74-μm vs. 2.3-μm radiances scatter plot, each of which corresponds to a group of aerosols with similar properties. We analyzed Akatsuki/IR2 images to characterize the limb darkening for three night-side filters.There is, however, contamination from the intense day-side disk blurred by IR2's point spread function (PSF). It is found that infrared light can be multiplly reflected within the Si substrate of IR2 detector (1024x1024 pixels PtSi array), causing elongated tail in the actual PSF. We treated this in two different ways. One is to mathematically approximate the PSF (with a combination of modified Lorentz functions) and another is to differentiate 2.26-μm image from 2.32-μm image so that the blurred light pattern can directly be obtained. By comparing results from these two methods, we are able to reasonablly clean up the night-side images and limb darkening is extracted. Physical interpretation of limb darkening, as well as "true" time variations of cloud brightness will be presented/discussed.

Color reproduction software for a digital still camera

NASA Astrophysics Data System (ADS)

Lee, Bong S.; Park, Du-Sik; Nam, Byung D.

1998-04-01

We have developed a color reproduction software for a digital still camera. The image taken by the camera was colorimetrically reproduced on the monitor after characterizing the camera and the monitor, and color matching between two devices. The reproduction was performed at three levels; level processing, gamma correction, and color transformation. The image contrast was increased after the level processing adjusting the level of dark and bright portions of the image. The relationship between the level processed digital values and the measured luminance values of test gray samples was calculated, and the gamma of the camera was obtained. The method for getting the unknown monitor gamma was proposed. As a result, the level processed values were adjusted by the look-up table created by the camera and the monitor gamma correction. For a color transformation matrix for the camera, 3 by 3 or 3 by 4 matrix was used, which was calculated by the regression between the gamma corrected values and the measured tristimulus values of each test color samples the various reproduced images were displayed on the dialogue box implemented in our software, which were generated according to four illuminations for the camera and three color temperatures for the monitor. An user can easily choose he best reproduced image comparing each others.

Blinded evaluation of the effects of high definition and magnification on perceived image quality in laryngeal imaging.

PubMed

Otto, Kristen J; Hapner, Edie R; Baker, Michael; Johns, Michael M

2006-02-01

Advances in commercial video technology have improved office-based laryngeal imaging. This study investigates the perceived image quality of a true high-definition (HD) video camera and the effect of magnification on laryngeal videostroboscopy. We performed a prospective, dual-armed, single-blinded analysis of a standard laryngeal videostroboscopic examination comparing 3 separate add-on camera systems: a 1-chip charge-coupled device (CCD) camera, a 3-chip CCD camera, and a true 720p (progressive scan) HD camera. Displayed images were controlled for magnification and image size (20-inch [50-cm] display, red-green-blue, and S-video cable for 1-chip and 3-chip cameras; digital visual interface cable and HD monitor for HD camera). Ten blinded observers were then asked to rate the following 5 items on a 0-to-100 visual analog scale: resolution, color, ability to see vocal fold vibration, sense of depth perception, and clarity of blood vessels. Eight unblinded observers were then asked to rate the difference in perceived resolution and clarity of laryngeal examination images when displayed on a 10-inch (25-cm) monitor versus a 42-inch (105-cm) monitor. A visual analog scale was used. These monitors were controlled for actual resolution capacity. For each item evaluated, randomized block design analysis demonstrated that the 3-chip camera scored significantly better than the 1-chip camera (p < .05). For the categories of color and blood vessel discrimination, the 3-chip camera scored significantly better than the HD camera (p < .05). For magnification alone, observers rated the 42-inch monitor statistically better than the 10-inch monitor. The expense of new medical technology must be judged against its added value. This study suggests that HD laryngeal imaging may not add significant value over currently available video systems, in perceived image quality, when a small monitor is used. Although differences in clarity between standard and HD cameras may not be readily apparent on small displays, a large display size coupled with HD technology may impart improved diagnosis of subtle vocal fold lesions and vibratory anomalies.

O+ pickup ions outside of Venus' bow shock: Venus Express observation

NASA Astrophysics Data System (ADS)

Wei, Y.; Fraenz, M.; Dubinin, E.; Zhang, T. L.; Wan, W.; Barabash, S.; Woch, J.; Lundin, R.

2012-09-01

Pickup ions are ions of planetary origin that become assimilated into the solar wind flow through their interaction with the solar wind magnetic and electric field. The speed of pickup ions varies between zero and twice the underlying plasma flow component perpendicular to magnetic field vector. For the unmagnetized planet Venus and Mars, oxygen (O+) pickup ions are known to be important because they can modify the global configuration of planetary plasma environment and significantly contribute to the atmospheric O+ loss [1]. Since the kinetic energy of an O+ pickup ion can reach 64 times that of a co-moving proton, an instrument must be able to measure O+ ions with energy of at least tens of keV to investigate the O+ pickup ion distribution from planetary ionosphere to solar wind. The in-situ observations and simulations at Mars have shown that the energy of O+ pickup ions can be 55-72 keV outside of the bow shock [2]. For Venus case, the plasma analyzer (OPA) onboard Pioneer Venus Orbiter (PVO), which was designed for solar wind monitoring, has an 8 keV energy limit for O+ detection and the limited sampling and data rate [3]. Therefore, OPA can only measure the O+ pickup ions in the sheath flow or inside the induced magnetosphere where the speed of ambient plasma flow is significantly lower than that of the unshocked solar wind outside of the bow shock. The Ion Mass Analyzer (IMA), included in the Analyzer of Space Plasma and Energetic Atoms (ASPERA-4) package on board Venus Express (VEX), determines the composition, energy, and angular distribution of ions in the energy range ~10 eV/q to 30 keV/q. Note that an O+ ion moving at the typical solar wind speed 400 km/s has kinetic energy 13.4 keV. Therefore, IMA has ability to measure the O+ pickup ions outside of Venus' bow shock. We have examined the IMA data during the solar minimum period 2006-2010, and identified about ten cases with clear signature of O+ pickup ion. With these observations, we will determine the location and the scale height of the source region of O+ pickup ions and describe the relationship between the behavior of these O+ and the upstream solar wind condition. The results would provide new information for numerical simulation of plasma environment near Venus and contribute to estimation of total O+ ion loss from Venus.

O+ pickup ions outside of Venus' bow shock: Venus Express observations

NASA Astrophysics Data System (ADS)

Wei, Yong; Fraenz, Markus; Dubinin, Eduard; Zhang, Tielong; Jarvinen, Riku; Wan, Weixing; Kallio, Esa; Collinson, Glyn; Barabash, Stars; Norbert, Krupp; Woch, Joachim; Lundin, Rickard; delva, Magda

2013-04-01

Pickup ions are ions of planetary origin that become assimilated into the solar wind flow through their interaction with the solar wind magnetic and electric field. The speed of pickup ions varies between zero and twice the underlying plasma flow component perpendicular to magnetic field vector. For the unmagnetized planet Venus and Mars, oxygen (O+) pickup ions are known to be important because they can modify the global configuration of planetary plasma environment and significantly contribute to the atmospheric O+ loss [1]. Since the kinetic energy of an O+ pickup ion can reach 64 times that of a co-moving proton, an instrument must be able to measure O+ ions with energy of at least tens of keV to investigate the O+ pickup ion distribution from planetary ionosphere to solar wind. The in-situ observations and simulations at Mars have shown that the energy of O+ pickup ions can be 55-72 keV outside of the bow shock [2]. For Venus case, the plasma analyzer (OPA) onboard Pioneer Venus Orbiter (PVO), which was designed for solar wind monitoring, has an 8 keV energy limit for O+ detection and the limited sampling and data rate [3]. Therefore, OPA can only measure the O+ pickup ions in the sheath flow or inside the induced magnetosphere where the speed of ambient plasma flow is significantly lower than that of the unshocked solar wind outside of the bow shock. In addition, Galileo also did not capture O+ outside bowshock during its 1-hour Venus flyby though its plasma instrument had ability to cover the energy band of O+ pickup ions [4]. The Ion Mass Analyzer (IMA), included in the Analyzer of Space Plasma and Energetic Atoms (ASPERA-4) package on board Venus Express (VEX), determines the composition, energy, and angular distribution of ions in the energy range ~10 eV/q to 30 keV/q. Note that an O+ ion moving at the typical solar wind speed 400 km/s has kinetic energy 13.4 keV. Therefore, IMA has ability to measure the O+ pickup ions outside of Venus' bow shock. We have examined the IMA data during the solar minimum period 2006-2010, and identified 80 cases with clear signature of O+ pickup ion. With these observations, we can determine the location and the scale height of the source region of O+ pickup ions and describe the relationship between the behavior of these O+ and the upstream solar wind condition. The results would provide new information for numerical simulation of plasma environment near Venus and contribute to estimation of total O+ ion loss from Venus. Reference: [1] Dubinin, E., M. Fränz, J. Woch, E. Roussos, S. Barabash, R. Lundin, J. D. Winningham, R. A. Frahm, and M. Acuña (2006a), Plasma morphology at Mars: Aspera-3 observations, Space Sci. Rev., 126, 209-238, doi:10.1007/s11214-006-9039-4. [2] Cravens, T. E., A. Hoppe, S. A. Ledvina, and S. McKenna-Lawlor (2002), Pickup ions near Mars associated with escaping oxygen atoms, J. Geophys. Res., 107, 1170, doi:10.1029/2001JA000125. [3] Luhmann, J. G., S. A. Ledvina, J. G. Lyon, and C. T. Russell (2006), Venus O+ pickup ions: Collected PVO results and expectations for Venus Express, Planet. Space Sci., 54, 1457-1471, doi:10.1016/j.pss.2005.10.009. [4] Williams, D. J. et al.(1991), Energetic Particles at Venus: Galileo Results. Science 253, 1525-1528.

Low, slow, small target recognition based on spatial vision network

NASA Astrophysics Data System (ADS)

Cheng, Zhao; Guo, Pei; Qi, Xin

2018-03-01

Traditional photoelectric monitoring is monitored using a large number of identical cameras. In order to ensure the full coverage of the monitoring area, this monitoring method uses more cameras, which leads to more monitoring and repetition areas, and higher costs, resulting in more waste. In order to reduce the monitoring cost and solve the difficult problem of finding, identifying and tracking a low altitude, slow speed and small target, this paper presents spatial vision network for low-slow-small targets recognition. Based on camera imaging principle and monitoring model, spatial vision network is modeled and optimized. Simulation experiment results demonstrate that the proposed method has good performance.

Lunar and Planetary Science XXXV: Venus

NASA Technical Reports Server (NTRS)

2004-01-01

The session "Venus" included the following reports:Preliminary Study of Laser-induced Breakdown Spectroscopy (LIBS) for a Venus Mission; Venus Surface Investigation Using VIRTIS Onboard the ESA/Venus Express Mission; Use of Magellan Images for Venus Landing Safety Assessment; Volatile Element Geochemistry in the Lower Atmosphere of Venus; Resurfacing Styles and Rates on Venus: Assessment of 18 Venusian Quadrangles; Stereo Imaging of Impact Craters in the Beta-Atla-Themis (BAT) Region, Venus; Depths of Extended Crater-related Deposits on Venus ; Potential Pyroclastic Deposit in the Nemesis Tessera (V14) Quadrangle of Venus; Relationship Between Coronae, Regional Plains and Rift Zones on Venus, Preliminary Results; Coronae of Parga Chasma, Venus; The Evolution of Four Volcano/Corona Hybrids on Venus; Calderas on Venus and Earth: Comparison and Models of Formation; Venus Festoon Deposits: Analysis of Characteristics and Modes of Emplacement; Topographic and Structural Analysis of Devana Chasma, Venus: A Propagating Rift System; Anomalous Radial Structures at Irnini Mons, Venus: A Parametric Study of Stresses on a Pressurized Hole; Analysis of Gravity and Topography Signals in Atalanta-Vinmara and Lavinia Planitiae Canali are Lava, Not River, Channels; and Formation of Venusian Channels in a Shield Paint Substrate.

Venus flytrap biomechanics: forces in the Dionaea muscipula trap.

PubMed

Volkov, Alexander G; Harris, Shawn L; Vilfranc, Chrystelle L; Murphy, Veronica A; Wooten, Joseph D; Paulicin, Henoc; Volkova, Maia I; Markin, Vladislav S

2013-01-01

Biomechanics of morphing structures in the Venus flytrap has attracted the attention of scientists during the last 140 years. The trap closes in a tenth of a second if a prey touches a trigger hair twice. The driving force of the closing process is most likely due to the elastic curvature energy stored and locked in the leaves, which is caused by a pressure differential between the upper and lower layers of the leaf. The trap strikes, holds and compresses the prey. We have developed new methods for measuring all these forces involved in the hunting cycle. We made precise calibration of the piezoelectric sensor and performed direct measurements of the average impact force of the trap closing using a high speed video camera for the determination of time constants. The new equation for the average impact force was derived. The impact average force between rims of two lobes in the Venus flytrap was found equal to 149 mN and the corresponding pressure between the rims was about 41 kPa. Direct measurements of the constriction force in the trap of Dionaea muscipula was performed during gelatin digestion. This force increases in the process of digestion from zero to 450 mN with maximal constriction pressure created by the lobes reaching to 9 kPa. The insects and different small prey have little chance to escape after the snap of the trap. The prey would need to overpower the "escaping" force which is very strong and can reach up to 4N. Copyright © 2012 Elsevier GmbH. All rights reserved.

Dynamic calibration of pan-tilt-zoom cameras for traffic monitoring.

PubMed

Song, Kai-Tai; Tai, Jen-Chao

2006-10-01

Pan-tilt-zoom (PTZ) cameras have been widely used in recent years for monitoring and surveillance applications. These cameras provide flexible view selection as well as a wider observation range. This makes them suitable for vision-based traffic monitoring and enforcement systems. To employ PTZ cameras for image measurement applications, one first needs to calibrate the camera to obtain meaningful results. For instance, the accuracy of estimating vehicle speed depends on the accuracy of camera calibration and that of vehicle tracking results. This paper presents a novel calibration method for a PTZ camera overlooking a traffic scene. The proposed approach requires no manual operation to select the positions of special features. It automatically uses a set of parallel lane markings and the lane width to compute the camera parameters, namely, focal length, tilt angle, and pan angle. Image processing procedures have been developed for automatically finding parallel lane markings. Interesting experimental results are presented to validate the robustness and accuracy of the proposed method.

Efficient color correction method for smartphone camera-based health monitoring application.

PubMed

Duc Dang; Chae Ho Cho; Daeik Kim; Oh Seok Kwon; Jo Woon Chong

2017-07-01

Smartphone health monitoring applications are recently highlighted due to the rapid development of hardware and software performance of smartphones. However, color characteristics of images captured by different smartphone models are dissimilar each other and this difference may give non-identical health monitoring results when the smartphone health monitoring applications monitor physiological information using their embedded smartphone cameras. In this paper, we investigate the differences in color properties of the captured images from different smartphone models and apply a color correction method to adjust dissimilar color values obtained from different smartphone cameras. Experimental results show that the color corrected images using the correction method provide much smaller color intensity errors compared to the images without correction. These results can be applied to enhance the consistency of smartphone camera-based health monitoring applications by reducing color intensity errors among the images obtained from different smartphones.

Planetary maps

USGS Publications Warehouse

,

1992-01-01

An important goal of the USGS planetary mapping program is to systematically map the geology of the Moon, Mars, Venus, and Mercury, and the satellites of the outer planets. These geologic maps are published in the USGS Miscellaneous Investigations (I) Series. Planetary maps on sale at the USGS include shaded-relief maps, topographic maps, geologic maps, and controlled photomosaics. Controlled photomosaics are assembled from two or more photographs or images using a network of points of known latitude and longitude. The images used for most of these planetary maps are electronic images, obtained from orbiting television cameras, various optical-mechanical systems. Photographic film was only used to map Earth's Moon.

Outcrops of plastic material on the surface of Venus

NASA Astrophysics Data System (ADS)

Ksanfomality, L. V.

2015-05-01

The archive data of the television experiment performed by the Venera-14 spacecraft on the surface of the planet Venus in March, 1982, were reprocessed, which significantly improved the image definition quality. An unusual geologic object located relatively near the camera was found, which allowed its details to be analyzed. The object is a low long bank in shape; it is formed by a relatively thin, jagged, almost vertical stratum. The bank contours the oval formation 1.5-2 m across that stands out against the layered surface. The location of the bank suggests that its material is extruded from under the layered plates surrounding the oval formation. A segment of the bank resembling a falling wave is inclined and partly covers the surface by forming the beddings. The object is likely formed by the rocks that remain semisoftened (plastic), when they appear on the surface at the temperature characteristic for the Venusian surface (about 740 K). It is suggested that, from the data on the physical and chemical conditions and the composition of the Venusian surface, the nature of the observed plastic medium can be hypothesized, and it can be even modeled under laboratory conditions.

Benefit assessment of NASA space technology goals

NASA Technical Reports Server (NTRS)

1976-01-01

The socio-economic benefits to be derived from system applications of space technology goals developed by NASA were assessed. Specific studies include: electronic mail; personal telephone communications; weather and climate monitoring, prediction, and control; crop production forecasting and water availability; planetary engineering of the planet Venus; and planetary exploration.

Optical Transient Monitor (OTM) for BOOTES Project

NASA Astrophysics Data System (ADS)

Páta, P.; Bernas, M.; Castro-Tirado, A. J.; Hudec, R.

2003-04-01

The Optical Transient Monitor (OTM) is a software for control of three wide and ultra-wide filed cameras of BOOTES (Burst Observer and Optical Transient Exploring System) station. The OTM is a PC based and it is powerful tool for taking images from two SBIG CCD cameras in same time or from one camera only. The control program for BOOTES cameras is Windows 98 or MSDOS based. Now the version for Windows 2000 is prepared. There are five main supported modes of work. The OTM program could control cameras and evaluate image data without human interaction.

Local Observations, Global Connections: An Educational Program Using Ocean Networks Canada's Community-Based Observatories

NASA Astrophysics Data System (ADS)

Pelz, M.; Hoeberechts, M.; Ewing, N.; Davidson, E.; Riddell, D. J.

2014-12-01

Schools on Canada's west coast and in the Canadian Arctic are participating in the pilot year of a novel educational program based on analyzing, understanding and sharing ocean data collected by cabled observatories. The core of the program is "local observations, global connections." First, students develop an understanding of ocean conditions at their doorstep through the analysis of community-based observatory data. Then, they connect that knowledge with the health of the global ocean by engaging with students at other schools participating in the educational program and through supplemental educational resources. Ocean Networks Canada (ONC), an initiative of the University of Victoria, operates cabled ocean observatories which supply continuous power and Internet connectivity to a broad suite of subsea instruments from the coast to the deep sea. This Internet connectivity permits researchers, students and members of the public to download freely available data on their computers anywhere around the globe, in near real-time. In addition to the large NEPTUNE and VENUS cabled observatories off the coast of Vancouver Island, British Columbia, ONC has been installing smaller, community-based cabled observatories. Currently two are installed: one in Cambridge Bay, Nunavut and one at Brentwood College School, on Mill Bay in Saanich Inlet, BC. Several more community-based observatories are scheduled for installation within the next year. The observatories support a variety of subsea instruments, such as a video camera, hydrophone and water quality monitor and shore-based equipment including a weather station and a video camera. Schools in communities hosting an observatory are invited to participate in the program, alongside schools located in other coastal and inland communities. Students and teachers access educational material and data through a web portal, and use video conferencing and social media tools to communicate their findings. A series of lesson plans introduces the teachers and students to cabled observatory technology and instrumentation, including technical aspects and their value in monitoring changing ocean conditions. This presentation will describe the program in more detail and report on our experiences in the first months of the pilot year.

Cabled observatories: Connecting coastal communities to local ocean data

NASA Astrophysics Data System (ADS)

Pelz, M.; Hoeberechts, M.; Brown, J. C. K.; McLean, M. A.; Ewing, N.; Moran, K.

2015-12-01

Coastal communities are facing a wide range of rapid changes due to anthropogenic and natural environmental influences. Communities are under pressure to adapt to effects of climate change, including altered shorelines, changes in availability of seafood, and in northern regions, changes to the extent, formation and break-up of land-fast and sea-ice. Access to up-to-date scientific data and basic climate literacy are essential tools to enable community members to make informed decisions about their own coast. Ocean Networks Canada (ONC) operates the world-leading NEPTUNE and VENUS cabled ocean observatories off the west coast of British Columbia (BC). ONC also operates smaller, coastal community observatories which provide data for both scientific and educational initiatives.The first Arctic community observatory, deployed in 2012, is located in Cambridge Bay, Nunavut. Real-time data flowing from the platform are collected by a range of instruments, including a conductivity-temperature-depth sensor (CTD), hydrophone, video camera, and an ice profiler. There is also a meteorological station and time lapse camera on the dock. Five additional community observatories are being installed over the next year along the coast of BC. Indigenous communities, including the Inuit population in Cambridge Bay and First Nations on BC's north and central coast, are key partners and collaborators of this initiative.Benefits to communities from cabled observatory ocean monitoring can only be achieved if the data collected are relevant to community members and contribute to research priorities identified within the community. The data must be easily accessible and complement existing environmental monitoring initiatives. Community members must possess knowledge and tools to analyze and interpret the data for their purposes. For these reasons, community involvement is critical to the project, including the design of user interfaces for data access, development of educational programs, and long-term planning.Here we describe Ocean Networks Canada's community initiatives including collaboration with Indigenous knowledge holders and local experts, programs in community schools to foster K-12 climate literacy and post-secondary programs targeted to community members.

Docking alignment system

NASA Technical Reports Server (NTRS)

Monford, Leo G. (Inventor)

1990-01-01

Improved techniques are provided for alignment of two objects. The present invention is particularly suited for three-dimensional translation and three-dimensional rotational alignment of objects in outer space. A camera 18 is fixedly mounted to one object, such as a remote manipulator arm 10 of the spacecraft, while the planar reflective surface 30 is fixed to the other object, such as a grapple fixture 20. A monitor 50 displays in real-time images from the camera, such that the monitor displays both the reflected image of the camera and visible markings on the planar reflective surface when the objects are in proper alignment. The monitor may thus be viewed by the operator and the arm 10 manipulated so that the reflective surface is perpendicular to the optical axis of the camera, the roll of the reflective surface is at a selected angle with respect to the camera, and the camera is spaced a pre-selected distance from the reflective surface.

Improved docking alignment system

NASA Technical Reports Server (NTRS)

Monford, Leo G. (Inventor)

1988-01-01

Improved techniques are provided for the alignment of two objects. The present invention is particularly suited for 3-D translation and 3-D rotational alignment of objects in outer space. A camera is affixed to one object, such as a remote manipulator arm of the spacecraft, while the planar reflective surface is affixed to the other object, such as a grapple fixture. A monitor displays in real-time images from the camera such that the monitor displays both the reflected image of the camera and visible marking on the planar reflective surface when the objects are in proper alignment. The monitor may thus be viewed by the operator and the arm manipulated so that the reflective surface is perpendicular to the optical axis of the camera, the roll of the reflective surface is at a selected angle with respect to the camera, and the camera is spaced a pre-selected distance from the reflective surface.

Scaling-up camera traps: monitoring the planet's biodiversity with networks of remote sensors

USGS Publications Warehouse

Steenweg, Robin; Hebblewhite, Mark; Kays, Roland; Ahumada, Jorge A.; Fisher, Jason T.; Burton, Cole; Townsend, Susan E.; Carbone, Chris; Rowcliffe, J. Marcus; Whittington, Jesse; Brodie, Jedediah; Royle, Andy; Switalski, Adam; Clevenger, Anthony P.; Heim, Nicole; Rich, Lindsey N.

2017-01-01

Countries committed to implementing the Convention on Biological Diversity's 2011–2020 strategic plan need effective tools to monitor global trends in biodiversity. Remote cameras are a rapidly growing technology that has great potential to transform global monitoring for terrestrial biodiversity and can be an important contributor to the call for measuring Essential Biodiversity Variables. Recent advances in camera technology and methods enable researchers to estimate changes in abundance and distribution for entire communities of animals and to identify global drivers of biodiversity trends. We suggest that interconnected networks of remote cameras will soon monitor biodiversity at a global scale, help answer pressing ecological questions, and guide conservation policy. This global network will require greater collaboration among remote-camera studies and citizen scientists, including standardized metadata, shared protocols, and security measures to protect records about sensitive species. With modest investment in infrastructure, and continued innovation, synthesis, and collaboration, we envision a global network of remote cameras that not only provides real-time biodiversity data but also serves to connect people with nature.

Clinical applications of commercially available video recording and monitoring systems: inexpensive, high-quality video recording and monitoring systems for endoscopy and microsurgery.

PubMed

Tsunoda, Koichi; Tsunoda, Atsunobu; Ishimoto, ShinnIchi; Kimura, Satoko

2006-01-01

The exclusive charge-coupled device (CCD) camera system for the endoscope and electronic fiberscopes are in widespread use. However, both are usually stationary in an office or examination room, and a wheeled cart is needed for mobility. The total costs of the CCD camera system and electronic fiberscopy system are at least US Dollars 10,000 and US Dollars 30,000, respectively. Recently, the performance of audio and visual instruments has improved dramatically, with a concomitant reduction in their cost. Commercially available CCD video cameras with small monitors have become common. They provide excellent image quality and are much smaller and less expensive than previous models. The authors have developed adaptors for the popular mini-digital video (mini-DV) camera. The camera also provides video and acoustic output signals; therefore, the endoscopic images can be viewed on a large monitor simultaneously. The new system (a mini-DV video camera and an adaptor) costs only US Dollars 1,000. Therefore, the system is both cost-effective and useful for the outpatient clinic or casualty setting, or on house calls for the purpose of patient education. In the future, the authors plan to introduce the clinical application of a high-vision camera and an infrared camera as medical instruments for clinical and research situations.

Movable Cameras And Monitors For Viewing Telemanipulator

NASA Technical Reports Server (NTRS)

Diner, Daniel B.; Venema, Steven C.

1993-01-01

Three methods proposed to assist operator viewing telemanipulator on video monitor in control station when video image generated by movable video camera in remote workspace of telemanipulator. Monitors rotated or shifted and/or images in them transformed to adjust coordinate systems of scenes visible to operator according to motions of cameras and/or operator's preferences. Reduces operator's workload and probability of error by obviating need for mental transformations of coordinates during operation. Methods applied in outer space, undersea, in nuclear industry, in surgery, in entertainment, and in manufacturing.

Greenhouse effects on Venus

NASA Astrophysics Data System (ADS)

Bell, Peter M.

Calculations that used Pioneer-Venus measurements of atmosphere composition, temperature profiles, and radiative heating predicted Venus' surface temperature ‘very precisely,’ says the Ames Research Center. The calculations predict not only Venus' surface temperature but agree with temperatures measured at various altitudes above the surface by the four Pioneer Venus atmosphere probe craft.Using Pioneer-Venus spacecraft data, a research team has virtually proved that the searing 482° C surface temperature of Venus is due to an atmospheric greenhouse effect. Until now the Venus greenhouse effect has been largely a theory.

Comparative analysis of three different methods for monitoring the use of green bridges by wildlife.

PubMed

Gužvica, Goran; Bošnjak, Ivana; Bielen, Ana; Babić, Danijel; Radanović-Gužvica, Biserka; Šver, Lidija

2014-01-01

Green bridges are used to decrease highly negative impact of roads/highways on wildlife populations and their effectiveness is evaluated by various monitoring methods. Based on the 3-year monitoring of four Croatian green bridges, we compared the effectiveness of three indirect monitoring methods: track-pads, camera traps and active infrared (IR) trail monitoring system. The ability of the methods to detect different species and to give good estimation of number of animal crossings was analyzed. The accuracy of species detection by track-pad method was influenced by granulometric composition of track-pad material, with the best results obtained with higher percentage of silt and clay. We compared the species composition determined by track-pad and camera trap methods and found that monitoring by tracks underestimated the ratio of small canids, while camera traps underestimated the ratio of roe deer. Regarding total number of recorder events, active IR detectors recorded from 11 to 19 times more events then camera traps and app. 80% of them were not caused by animal crossings. Camera trap method underestimated the real number of total events. Therefore, an algorithm for filtration of the IR dataset was developed for approximation of the real number of crossings. Presented results are valuable for future monitoring of wildlife crossings in Croatia and elsewhere, since advantages and disadvantages of used monitoring methods are shown. In conclusion, different methods should be chosen/combined depending on the aims of the particular monitoring study.

On-line, continuous monitoring in solar cell and fuel cell manufacturing using spectral reflectance imaging

DOEpatents

Sopori, Bhushan; Rupnowski, Przemyslaw; Ulsh, Michael

2016-01-12

A monitoring system 100 comprising a material transport system 104 providing for the transportation of a substantially planar material 102, 107 through the monitoring zone 103 of the monitoring system 100. The system 100 also includes a line camera 106 positioned to obtain multiple line images across a width of the material 102, 107 as it is transported through the monitoring zone 103. The system 100 further includes an illumination source 108 providing for the illumination of the material 102, 107 transported through the monitoring zone 103 such that light reflected in a direction normal to the substantially planar surface of the material 102, 107 is detected by the line camera 106. A data processing system 110 is also provided in digital communication with the line camera 106. The data processing system 110 is configured to receive data output from the line camera 106 and further configured to calculate and provide substantially contemporaneous information relating to a quality parameter of the material 102, 107. Also disclosed are methods of monitoring a quality parameter of a material.

Making The Invisible Visible

NASA Technical Reports Server (NTRS)

1978-01-01

In public and private archives throughout the world there are many historically important documents that have become illegible with the passage of time. They have faded, been erased, acquired mold, water and dirt stain, suffered blotting or lost readability in other ways. While ultraviolet and infrared photography are widely used to enhance deteriorated legibility, these methods are more limited in their effectiveness than the space-derived image enhancement technique. The aim of the JPL effort with Caltech and others is to better define the requirements for a system to restore illegible information for study at a low page-cost with simple operating procedures. The investigators' principle tools are a vidicon camera and an image processing computer program, the same equipment used to produce sharp space pictures. The camera is the same type as those on NASA's Mariner spacecraft which returned to Earth thousands of images of Mars, Venus and Mercury. Space imagery works something like television. The vidicon camera does not take a photograph in the ordinary sense; rather it "scans" a scene, recording different light and shade values which are reproduced as a pattern of dots, hundreds of dots to a line, hundreds of lines in the total picture. The dots are transmitted to an Earth receiver, where they are assembled line by line to form a picture like that on the home TV screen.

Outgassing history of Venus and the absence of water on Venus

NASA Technical Reports Server (NTRS)

Zhang, Youxue; Zindler, Alan

1992-01-01

Similarities in the size and mean density of Earth and Venus encourage the use of Earth-analogue models for the evolution of Venus. However, the amount of water in the present Venus atmosphere is miniscule compared to Earth's oceans. The 'missing' water is thus one of the most significant problems related to the origin and evolution of Venus. Other researchers proposed that Venus accreted with less water, but this was challenged. The high D/H ratio in Venus' atmosphere is consistent with an earlier water mass more than 100 times higher than at present conditions and is often cited to support a 'wet' Venus, but this amounts to only 0.01 to 0.1 percent of the water in terrestrial oceans and the high D/H ratio on Venus could easily reflect cometary injection. Nevertheless, many authors begin with the premise that Venus once had an oceanlike water mass on its surface, and investigate the many possible mechanisms that might account for its loss. In this paper we propose that Venus degassed to lower degree than the Earth and never had an oceanlike surface water mass.

IR heterodyne spectrometer MILAHI for continuous monitoring observatory of Martian and Venusian atmospheres at Mt. Haleakalā, Hawaii

NASA Astrophysics Data System (ADS)

Nakagawa, Hiromu; Aoki, Shohei; Sagawa, Hideo; Kasaba, Yasumasa; Murata, Isao; Sonnabend, Guido; Sornig, Manuela; Okano, Shoichi; Kuhn, Jeffrey R.; Ritter, Joseph M.; Kagitani, Masato; Sakanoi, Takeshi; Taguchi, Makoto; Takami, Kosuke

2016-07-01

A new Mid-Infrared Laser Heterodyne Instrument (MILAHI) with >106 resolving power at 7-12 μm was developed for continuous monitoring of planetary atmospheres by using dedicated ground-based telescopes for planetary science at Mt. Haleakalā, Hawaii. Room-temperature-type quantum cascade lasers (QCLs) that cover wavelength ranges of 7.69-7.73, 9.54-9.59, and 10.28-10.33 μm have been newly installed as local oscillators to allow observation of CO2, CH4, H2O2, H2O, and HDO. Modeling and predictions by radiative transfer code gave the following scientific capabilities and measurement sensitivities of the MILAHI. (1) Temperature profiles are achieved at altitudes of 65-90 km on Venus, and the ground surface to 30 km on Mars. (2) New wind profiles are provided at altitudes of 75-90 km on Venus, and 5-25 km on Mars. (3) Direct measurements of the mesospheric wind and temperature are obtained from the Doppler-shifted emission line at altitudes of 110 km on Venus and 75 km on Mars. (4) Detections of trace gases and isotopic ratios are performed without any ambiguity of the reproducing the terrestrial atmospheric absorptions in the observed wavelength range. A HDO measurement of twice the Vienna Standard Mean Ocean Water (VSMOW) can be obtained by 15-min integration, while H2O of 75 ppm is provided by 3.62-h integration. The detectability of the 100 ppb-CH4 on Mars corresponds to an integration time of 32 h.

Coronae as a result of giant magma intrusions in the lithosphere of Venus: insights from laboratory experiments

NASA Astrophysics Data System (ADS)

Galland, Olivier; Polteau, Stephane; Werner, Stephanie C.

2013-04-01

Coronae on the surface of Venus are unique volcano-tectonic structures in the solar systems. Their circular morphology is associated with various topographic signatures, from bell-shape domes, flat-topped plateaus, to uplifted rings surrounding a subsided centre similar to caldera. Their extensive size and associated lava flows erupting from their periphery, indicate that they result from deep processes in the Venus mantle. Understanding their origin is thus essential for unraveling the dynamics of Venus through time. There are several scenarios explaining the formation of coronae, the most popular being the interaction between an upwelling mantle plume and the lithosphere, creating dynamic topography. In this contribution, we propose that coronae can result from the emplacement of giant magma intrusions below the Venus' lithosphere, on the basis of laboratory experiments. The experimental apparatus consists of a square box filled with compacted fine-grained silica flour (model crust), in which a low viscosity vegetable oil (model magma) is injected at constant flow rate. The initial conditions are such that magma initially flows horizontally, forming a sill-like body, to simulate magmatic underplating. During the experiments, oil injection triggers deformation of the model surface, which is monitored periodically using a moiré projection device, producing time series topographic maps of the model surface. Our results show that the surface evolution of the models follows three stages: (1) initial bell-shaped doming occurs above the injection inlet, producing radial open fractures at the model surfaces; (2) the bell-shape dome evolves to a flat-topped plateau, at the rim of which the oil erupts; (3) after the injection stops, the centre of the plateau subsides, and a positive topographic ring surrounding a depression, like a caldera, remains. The collapse of the plateau also generates concentric extensional fractures at the rims of the caldera. After the dynamic experiment, the oil solidifies and we extracted the intrusion, which exhibits a sill-shape, feeding outward circular inclined sheets at its external edges (i.e. a saucer-shaped sill). From a series of experiments in which the depth of injection h was varied, we show that the diameter of the intrusion and its associated topographic structure correlates linearly with h. The three evolutionary stages simulated in the experiments reproduce remarkably well (1) the three main corona morphologies observed on Venus, and (2) their established succession through time. In addition, the relationships between the structures and the oil flow in our experiments are also similar to those observed on Venus. Therefore, our experimental results suggest that corona structures are the result of giant magma intrusions in the lithosphere of Venus. In addition, our experiments suggest that the diameters of coronae are related to the depth of emplacement of the underlying intrusions, which might be controlled by the rheological architecture of the Venus' lithosphere. Therefore, the analysis of the dimensions and morphologies of coronae are likely to provide crucial information of the structure of the lithosphere of Venus.

Seasonal variations of leaf and canopy properties tracked by ground-based NDVI imagery in a temperate forest.

PubMed

Yang, Hualei; Yang, Xi; Heskel, Mary; Sun, Shucun; Tang, Jianwu

2017-04-28

Changes in plant phenology affect the carbon flux of terrestrial forest ecosystems due to the link between the growing season length and vegetation productivity. Digital camera imagery, which can be acquired frequently, has been used to monitor seasonal and annual changes in forest canopy phenology and track critical phenological events. However, quantitative assessment of the structural and biochemical controls of the phenological patterns in camera images has rarely been done. In this study, we used an NDVI (Normalized Difference Vegetation Index) camera to monitor daily variations of vegetation reflectance at visible and near-infrared (NIR) bands with high spatial and temporal resolutions, and found that the infrared camera based NDVI (camera-NDVI) agreed well with the leaf expansion process that was measured by independent manual observations at Harvard Forest, Massachusetts, USA. We also measured the seasonality of canopy structural (leaf area index, LAI) and biochemical properties (leaf chlorophyll and nitrogen content). We found significant linear relationships between camera-NDVI and leaf chlorophyll concentration, and between camera-NDVI and leaf nitrogen content, though weaker relationships between camera-NDVI and LAI. Therefore, we recommend ground-based camera-NDVI as a powerful tool for long-term, near surface observations to monitor canopy development and to estimate leaf chlorophyll, nitrogen status, and LAI.

Feasibility study of a gamma camera for monitoring nuclear materials in the PRIDE facility

NASA Astrophysics Data System (ADS)

Jo, Woo Jin; Kim, Hyun-Il; An, Su Jung; Lee, Chae Young; Song, Han-Kyeol; Chung, Yong Hyun; Shin, Hee-Sung; Ahn, Seong-Kyu; Park, Se-Hwan

2014-05-01

The Korea Atomic Energy Research Institute (KAERI) has been developing pyroprocessing technology, in which actinides are recovered together with plutonium. There is no pure plutonium stream in the process, so it has an advantage of proliferation resistance. Tracking and monitoring of nuclear materials through the pyroprocess can significantly improve the transparency of the operation and safeguards. An inactive engineering-scale integrated pyroprocess facility, which is the PyRoprocess Integrated inactive DEmonstration (PRIDE) facility, was constructed to demonstrate engineering-scale processes and the integration of each unit process. the PRIDE facility may be a good test bed to investigate the feasibility of a nuclear material monitoring system. In this study, we designed a gamma camera system for nuclear material monitoring in the PRIDE facility by using a Monte Carlo simulation, and we validated the feasibility of this system. Two scenarios, according to locations of the gamma camera, were simulated using GATE (GEANT4 Application for Tomographic Emission) version 6. A prototype gamma camera with a diverging-slat collimator was developed, and the simulated and experimented results agreed well with each other. These results indicate that a gamma camera to monitor the nuclear material in the PRIDE facility can be developed.

Cost effective system for monitoring of fish migration with a camera

NASA Astrophysics Data System (ADS)

Sečnik, Matej; Brilly, Mitja; Vidmar, Andrej

2016-04-01

Within the European LIFE project Ljubljanica connects (LIFE10 NAT/SI/000142) we have developed a cost-effective solution for the monitoring of fish migration through the fish passes with the underwater camera. In the fish pass at Ambrožev trg and in the fish pass near the Fužine castle we installed a video camera called "Fishcam" to be able to monitor the migration of fish through the fish passes and success of its reconstruction. Live stream from fishcams installed in the fishpassesis available on our project website (http://ksh.fgg.uni-lj.si/ljubljanicaconnects/ang/12_camera). The system for the fish monitoring is made from two parts. First is the waterproof box for the computer with charger and the second part is the camera itself. We used a high sensitive Sony analogue camera. The advantage of this camera is that it has very good sensitivity in low light conditions, so it can take good quality pictures even at night with a minimum additional lighting. For the night recording we use additional IR reflector to illuminate passing fishes. The camera is connected to an 8-inch tablet PC. We decided to use a tablet PC because it is quite small, cheap, it is relatively fast and has a low power consumption. On the computer we use software which has advanced motion detection capabilities, so we can also detect the small fishes. When the fish is detected by a software, its photograph is automatically saved to local hard drive and for backup also on Google drive. The system for monitoring of fish migration has turned out to work very well. From the beginning of monitoring in June 2015 to end of the year there were more than 100.000 photographs produced. The first analysis of them was already prepared estimating fish species and their frequency in passing the fish pass.

Venus Global Reference Atmospheric Model Status and Planned Updates

NASA Technical Reports Server (NTRS)

Justh, H. L.; Dwyer Cianciolo, A. M.

2017-01-01

The Venus Global Reference Atmospheric Model (Venus-GRAM) was originally developed in 2004 under funding from NASA's In Space Propulsion (ISP) Aerocapture Project to support mission studies at the planet. Many proposals, including NASA New Frontiers and Discovery, as well as other studies have used Venus-GRAM to design missions and assess system robustness. After Venus-GRAM's release in 2005, several missions to Venus have generated a wealth of additional atmospheric data, yet few model updates have been made to Venus-GRAM. This paper serves to address three areas: (1) to present the current status of Venus-GRAM, (2) to identify new sources of data and other upgrades that need to be incorporated to maintain Venus-GRAM credibility and (3) to identify additional Venus-GRAM options and features that could be included to increase its capability. This effort will de-pend on understanding the needs of the user community, obtaining new modeling data and establishing a dedicated funding source to support continual up-grades. This paper is intended to initiate discussion that can result in an upgraded and validated Venus-GRAM being available to future studies and NASA proposals.

Beats: Video Monitors and Cameras.

ERIC Educational Resources Information Center

Worth, Frazier

1996-01-01

Presents a method to teach the concept of beats as a generalized phenomenon rather than teaching it only in the context of sound. Involves using a video camera to film a computer terminal, 16-mm projector, or TV monitor. (JRH)

Composite video and graphics display for multiple camera viewing system in robotics and teleoperation

NASA Technical Reports Server (NTRS)

Diner, Daniel B. (Inventor); Venema, Steven C. (Inventor)

1991-01-01

A system for real-time video image display for robotics or remote-vehicle teleoperation is described that has at least one robot arm or remotely operated vehicle controlled by an operator through hand-controllers, and one or more television cameras and optional lighting element. The system has at least one television monitor for display of a television image from a selected camera and the ability to select one of the cameras for image display. Graphics are generated with icons of cameras and lighting elements for display surrounding the television image to provide the operator information on: the location and orientation of each camera and lighting element; the region of illumination of each lighting element; the viewed region and range of focus of each camera; which camera is currently selected for image display for each monitor; and when the controller coordinate for said robot arms or remotely operated vehicles have been transformed to correspond to coordinates of a selected or nonselected camera.

Composite video and graphics display for camera viewing systems in robotics and teleoperation

NASA Technical Reports Server (NTRS)

Diner, Daniel B. (Inventor); Venema, Steven C. (Inventor)

1993-01-01

A system for real-time video image display for robotics or remote-vehicle teleoperation is described that has at least one robot arm or remotely operated vehicle controlled by an operator through hand-controllers, and one or more television cameras and optional lighting element. The system has at least one television monitor for display of a television image from a selected camera and the ability to select one of the cameras for image display. Graphics are generated with icons of cameras and lighting elements for display surrounding the television image to provide the operator information on: the location and orientation of each camera and lighting element; the region of illumination of each lighting element; the viewed region and range of focus of each camera; which camera is currently selected for image display for each monitor; and when the controller coordinate for said robot arms or remotely operated vehicles have been transformed to correspond to coordinates of a selected or nonselected camera.

Seasonal variations of leaf and canopy properties tracked by ground-based NDVI imagery in a temperate forest

DOE PAGES

Yang, Hualei; Yang, Xi; Heskel, Mary; ...

2017-04-28

Changes in plant phenology affect the carbon flux of terrestrial forest ecosystems due to the link between the growing season length and vegetation productivity. Digital camera imagery, which can be acquired frequently, has been used to monitor seasonal and annual changes in forest canopy phenology and track critical phenological events. However, quantitative assessment of the structural and biochemical controls of the phenological patterns in camera images has rarely been done. In this study, we used an NDVI (Normalized Difference Vegetation Index) camera to monitor daily variations of vegetation reflectance at visible and near-infrared (NIR) bands with high spatial and temporalmore » resolutions, and found that the infrared camera based NDVI (camera-NDVI) agreed well with the leaf expansion process that was measured by independent manual observations at Harvard Forest, Massachusetts, USA. We also measured the seasonality of canopy structural (leaf area index, LAI) and biochemical properties (leaf chlorophyll and nitrogen content). Here we found significant linear relationships between camera-NDVI and leaf chlorophyll concentration, and between camera-NDVI and leaf nitrogen content, though weaker relationships between camera-NDVI and LAI. Therefore, we recommend ground-based camera-NDVI as a powerful tool for long-term, near surface observations to monitor canopy development and to estimate leaf chlorophyll, nitrogen status, and LAI.« less

Seasonal variations of leaf and canopy properties tracked by ground-based NDVI imagery in a temperate forest

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Hualei; Yang, Xi; Heskel, Mary

Changes in plant phenology affect the carbon flux of terrestrial forest ecosystems due to the link between the growing season length and vegetation productivity. Digital camera imagery, which can be acquired frequently, has been used to monitor seasonal and annual changes in forest canopy phenology and track critical phenological events. However, quantitative assessment of the structural and biochemical controls of the phenological patterns in camera images has rarely been done. In this study, we used an NDVI (Normalized Difference Vegetation Index) camera to monitor daily variations of vegetation reflectance at visible and near-infrared (NIR) bands with high spatial and temporalmore » resolutions, and found that the infrared camera based NDVI (camera-NDVI) agreed well with the leaf expansion process that was measured by independent manual observations at Harvard Forest, Massachusetts, USA. We also measured the seasonality of canopy structural (leaf area index, LAI) and biochemical properties (leaf chlorophyll and nitrogen content). Here we found significant linear relationships between camera-NDVI and leaf chlorophyll concentration, and between camera-NDVI and leaf nitrogen content, though weaker relationships between camera-NDVI and LAI. Therefore, we recommend ground-based camera-NDVI as a powerful tool for long-term, near surface observations to monitor canopy development and to estimate leaf chlorophyll, nitrogen status, and LAI.« less

An evaluation of video cameras for collecting observational data on sanctuary-housed chimpanzees (Pan troglodytes).

PubMed

Hansen, Bethany K; Fultz, Amy L; Hopper, Lydia M; Ross, Stephen R

2018-05-01

Video cameras are increasingly being used to monitor captive animals in zoo, laboratory, and agricultural settings. This technology may also be useful in sanctuaries with large and/or complex enclosures. However, the cost of camera equipment and a lack of formal evaluations regarding the use of cameras in sanctuary settings make it challenging for facilities to decide whether and how to implement this technology. To address this, we evaluated the feasibility of using a video camera system to monitor chimpanzees at Chimp Haven. We viewed a group of resident chimpanzees in a large forested enclosure and compared observations collected in person and with remote video cameras. We found that via camera, the observer viewed fewer chimpanzees in some outdoor locations (GLMM post hoc test: est. = 1.4503, SE = 0.1457, Z = 9.951, p < 0.001) and identified a lower proportion of chimpanzees (GLMM post hoc test: est. = -2.17914, SE = 0.08490, Z = -25.666, p < 0.001) compared to in-person observations. However, the observer could view the 2 ha enclosure 15 times faster by camera compared to in person. In addition to these results, we provide recommendations to animal facilities considering the installation of a video camera system. Despite some limitations of remote monitoring, we posit that there are substantial benefits of using camera systems in sanctuaries to facilitate animal care and observational research. © 2018 Wiley Periodicals, Inc.

Title Requested

NASA Astrophysics Data System (ADS)

Limaye, S. S.; Prabhu, T.; Bhatt, B. C.; Anandrao, B. G.; Emerson, G.; Young, E. F.

2004-11-01

In order to obtain a better dataset for tracking features in near infrared images of Venus, coordinated observations were made from two telescopes in India - the 1m Mt. Abu telescope at Gurushikhar (Location: 24o 39' 8.8" North Latitude, 72o 46' 47.47", 1680 m above MSL, NICMOS III camera, 0.5 arcsec/pixel) and the 2m Optical-Infrared Himalayan Chandra Telescope at Hanle, Ladakh (32o 35' 46" North Latitude and 78o 57' 51" East Longitude, 4500 m above MSL, NIR Camera, 0.21 arcsec/pixel) during 4-10 May 2004 and 6 -10 July 2004 when similar observations were also made from IRTF (Young et al., 2004) and Nordic Optical Telescope (Warell et al., 2004) as well as APO and AAT. Images were obtained at 2.29 micron wavelength using the filters available at the telescopes and show considerable variability from day to day in the atmospheric features. Yet there is enough retention of structural features that suggest a lifetime of 7 days indicating one complete rotation as observed from HCT data taken in May 2004. These features are believed to originate at 52 km level above the Venus surface and the motions are consistent with a rotation rate of 63 m/s at the equator. When combined with those from NOT, IRTF, APO and AAT these observations will yield better information about the circulation at 52 km altitude than has been possible from previous observations. We acknowledge the support and hospitality extended to us to obtain these observations by the staff of Mt. Abu and the Chandra telescopes, in particular Rajesh Shat and Jinesh Jain. Mt. Abu Telescope is operated by Physical Research Laboratory (Ahmedabad, India) and the Chandra Telescope is operated by Center for Research and Education in Science and Technology, Indian Institute of Astrophysics (Bangalore, India). Both are supported by the Indian Space Research Organization

Continuous monitoring of Hawaiian volcanoes with thermal cameras

USGS Publications Warehouse

Patrick, Matthew R.; Orr, Tim R.; Antolik, Loren; Lee, Robert Lopaka; Kamibayashi, Kevan P.

2014-01-01

Continuously operating thermal cameras are becoming more common around the world for volcano monitoring, and offer distinct advantages over conventional visual webcams for observing volcanic activity. Thermal cameras can sometimes “see” through volcanic fume that obscures views to visual webcams and the naked eye, and often provide a much clearer view of the extent of high temperature areas and activity levels. We describe a thermal camera network recently installed by the Hawaiian Volcano Observatory to monitor Kīlauea’s summit and east rift zone eruptions (at Halema‘uma‘u and Pu‘u ‘Ō‘ō craters, respectively) and to keep watch on Mauna Loa’s summit caldera. The cameras are long-wave, temperature-calibrated models protected in custom enclosures, and often positioned on crater rims close to active vents. Images are transmitted back to the observatory in real-time, and numerous Matlab scripts manage the data and provide automated analyses and alarms. The cameras have greatly improved HVO’s observations of surface eruptive activity, which includes highly dynamic lava lake activity at Halema‘uma‘u, major disruptions to Pu‘u ‘Ō‘ō crater and several fissure eruptions.

Abstracts for the Venus Geoscience Tutorial and Venus Geologic Mapping Workshop

NASA Technical Reports Server (NTRS)

1989-01-01

Abstracts and tutorial are presented from the workshop. Representative titles are: Geology of Southern Guinevere Planitia, Venus, Based on Analyses of Goldstone Radar Data; Tessera Terrain: Characteristics and Models of Origin; Venus Volcanism; Rate Estimates from Laboratory Studies of Sulfur Gas-Solid Reactions; and A Morphologic Study of Venus Ridge Belts.

Evaluation of Trail-Cameras for Analyzing the Diet of Nesting Raptors Using the Northern Goshawk as a Model

PubMed Central

García-Salgado, Gonzalo; Rebollo, Salvador; Pérez-Camacho, Lorenzo; Martínez-Hesterkamp, Sara; Navarro, Alberto; Fernández-Pereira, José-Manuel

2015-01-01

Diet studies present numerous methodological challenges. We evaluated the usefulness of commercially available trail-cameras for analyzing the diet of Northern Goshawks (Accipiter gentilis) as a model for nesting raptors during the period 2007–2011. We compared diet estimates obtained by direct camera monitoring of 80 nests with four indirect analyses of prey remains collected from the nests and surroundings (pellets, bones, feather-and-hair remains, and feather-hair-and-bone remains combined). In addition, we evaluated the performance of the trail-cameras and whether camera monitoring affected Goshawk behavior. The sensitivity of each diet-analysis method depended on prey size and taxonomic group, with no method providing unbiased estimates for all prey sizes and types. The cameras registered the greatest number of prey items and were probably the least biased method for estimating diet composition. Nevertheless this direct method yielded the largest proportion of prey unidentified to species level, and it underestimated small prey. Our trail-camera system was able to operate without maintenance for longer periods than what has been reported in previous studies with other types of cameras. Initially Goshawks showed distrust toward the cameras but they usually became habituated to its presence within 1–2 days. The habituation period was shorter for breeding pairs that had previous experience with cameras. Using trail-cameras to monitor prey provisioning to nests is an effective tool for studying the diet of nesting raptors. However, the technique is limited by technical failures and difficulties in identifying certain prey types. Our study also shows that cameras can alter adult Goshawk behavior, an aspect that must be controlled to minimize potential negative impacts. PMID:25992956

Evaluation of trail-cameras for analyzing the diet of nesting raptors using the Northern Goshawk as a model.

PubMed

García-Salgado, Gonzalo; Rebollo, Salvador; Pérez-Camacho, Lorenzo; Martínez-Hesterkamp, Sara; Navarro, Alberto; Fernández-Pereira, José-Manuel

2015-01-01

Diet studies present numerous methodological challenges. We evaluated the usefulness of commercially available trail-cameras for analyzing the diet of Northern Goshawks (Accipiter gentilis) as a model for nesting raptors during the period 2007-2011. We compared diet estimates obtained by direct camera monitoring of 80 nests with four indirect analyses of prey remains collected from the nests and surroundings (pellets, bones, feather-and-hair remains, and feather-hair-and-bone remains combined). In addition, we evaluated the performance of the trail-cameras and whether camera monitoring affected Goshawk behavior. The sensitivity of each diet-analysis method depended on prey size and taxonomic group, with no method providing unbiased estimates for all prey sizes and types. The cameras registered the greatest number of prey items and were probably the least biased method for estimating diet composition. Nevertheless this direct method yielded the largest proportion of prey unidentified to species level, and it underestimated small prey. Our trail-camera system was able to operate without maintenance for longer periods than what has been reported in previous studies with other types of cameras. Initially Goshawks showed distrust toward the cameras but they usually became habituated to its presence within 1-2 days. The habituation period was shorter for breeding pairs that had previous experience with cameras. Using trail-cameras to monitor prey provisioning to nests is an effective tool for studying the diet of nesting raptors. However, the technique is limited by technical failures and difficulties in identifying certain prey types. Our study also shows that cameras can alter adult Goshawk behavior, an aspect that must be controlled to minimize potential negative impacts.

Venus

NASA Astrophysics Data System (ADS)

Fegley, B., Jr.

Venus is Earth's nearest planetary neighbor and has fascinated mankind since the dawn of history. Venus' clouds reflect most of the sunlight shining on the planet and make it the brightest object in the sky after the Sun and Moon. Venus is visible with the naked eye as an evening star until a few hours after sunset or as a morning star shortly before sunrise. Many ancient civilizations observed and worshipped Venus, which had a different name in each society, for example, Ishtar to the Babylonians, Aphrodite to the Greeks, Tai'pei to the Chinese, and Venus to the Romans. Venus has continued to play an important role in myth, literature, and science throughout history.

Wave granulation in the Venus' atmosphere

NASA Astrophysics Data System (ADS)

Kochemasov, G.

2007-08-01

In unique venusian planetary system the solid body rotates very slowly and the detached massive atmosphere very rapidly. However both together orbit Sun and their characteristic orbital frequency -1/ 0.62 year - places them in the regular row of planets assigning them characteristic only for Venus wave produced granulation with a granule size πR/6 [1& others]. Remind other bodies in the row with their granule sizes inversely proportional to their orbital frequencies: solar photosphere πR/60, Mercury πR/16, Venus πR/6, Earth πR/4, Mars πR/2, asteroids πR/1 (R-a body radius). Three planets have atmospheres with wave granulations having sizes equal to their lithospheric granules. But Venus, unlike Earth and Mars, has the detached atmosphere that can be considered as a separate body with its own orbital frequency around the center of the Venus' system. According to the correlation between an orbital frequency and a wave granule size the venusian wave granule will be πR/338 (a scale can be Earth: orbital frequency 1/ 1year, granule size πR/4 or Sun: frequency 1/1month, granule size πR/60). So, πR/338 = 57 km. This theoretical size is rather close to that observed by Galileo SC through a violet filter "the filamentary dark features. . . are here revealed to be composed of several dark nodules, like beads on a string, each about 60 miles across" (PIA00072). Actually all Venus' disc seen from a distance π1.7mln.miles is peppered with these fine features seen on a limit of resolution. So, the Venus' atmosphere has two main frequencies in the solar system with corresponding wave granulations: around Sun 1/225 days (granule πR/6) and around Venus 1/ 4 days (granule πR/338). As was done for the Moon, Phobos, Titan and other icy satellites of Saturn [2, 3, 4 & others] one can apply the wave modulation technique also for the atmosphere of Venus. The lower frequency modulates the higher one by dividing and multiplying it thus getting two side frequencies and corresponding them wave granule sizes. (1/338 : 1/6)πR = πR/56.3 = 342 km. (1/338 x 1/6)πR = πR/2028 = 9.5 km. The larger granules as well arranged network were seen in the near IR Galileo image PIA00073 (several miles below the visible cloud tops). The smaller granules, hopefully, will be detected by the Venus Express cameras. So, the wave planetology applying wave methods to solid planetary bodies and to surrounding them gaseous envelopes shows their structural unity. This understanding may help to analyze and predict very complex behavior of atmospheric sells at Earth (anticyclones up to 5000 km across or πR/4), other planets and Titan. Long time ago known the solar supergranules about 30000 km across were never fully understood. The comparative wave planetology placing them together with wave features of planets and satellites throws light on their origin and behavior and thus expands into an area of the solar physics. In this respect it is interesting to note that rather typical for Sun radio emission in 1 meter diapason also was never properly explained. But applying modulation of the solar photosphere frequency 1/ 1month by the Galaxy frequency 1/ 200 000 000 y. one can obtain such short waves [5]. Radio emissions of planets of the solar system also can be related to this modulation by Galaxy rotation [5]. References: [1] Kochemasov G.G. (1992) Comparison of blob tectonics (Venus) and pair tectonics (Earth) // LPS XXIII, Houston, LPI, pt. 2, 703-704; [2] Kochemasov G.G. (2000) Orbiting frequency modulation in Solar system and its imprint in shapes and structures of celestial bodies // Vernadsky-Brown microsymposium 32 on Comparative planetology, Oct. 9-11, 2000, Moscow, Russia, Abstracs, 88-89; [3] Kochemasov G.G. (2000) Titan: frequency modulation of warping waves // Geophys. Res. Abstr., v. 2, (CD-ROM); [4] Kochemasov G.G. (2005) Cassini' lessons: square craters, shoulderto- shoulder even-size aligned and in grids craters having wave interference nature must be taken out of an impact craters statistics to make it real // Vernadsky-Brown microsymposium-42 "Topics in Comparative Planetology", Oct. 10-12, 2005, Vernadsky Inst., Moscow, Russia, Abstr. m42_31, CD-ROM; [5] Kochemasov G.G. (2001) Inertia-gravity waves of various scales on celestial bodies surfaces, in vertical section and their relation to radiowaves // 34thVernadsky-Brown microsymposium 'Topics in comparative planetology", Moscow, Vernadsky Inst., Abstr., CD-ROM.

Wave granulation in the Venus' atmosphere

NASA Astrophysics Data System (ADS)

Kochemasov, G.

2007-08-01

In unique venusian planetary system the solid body rotates very slowly and the detached massive atmosphere very rapidly. However both together orbit Sun and their characteristic orbital frequency -1/ 0.62 year - places them in the regular row of planets assigning them characteristic only for Venus wave produced granulation with a granule size πR/6 [1& others]. Remind other bodies in the row with their granule sizes inversely proportional to their orbital frequencies: solar photosphere πR/60, Mercury πR/16, Venus πR/6, Earth πR/4, Mars πR/2, asteroids πR/1 (R-a body radius). Three planets have atmospheres with wave granulations having sizes equal to their lithospheric granules. But Venus, unlike Earth and Mars, has the detached atmosphere that can be considered as a separate body with its own orbital frequency around the center of the Venus' system. According to the correlation between an orbital frequency and a wave granule size the venusian wave granule will be πR/338 (a scale can be Earth: orbital frequency 1/ 1year, granule size πR/4 or Sun: frequency 1/1month, granule size πR/60). So, πR/338 = 57 km. This theoretical size is rather close to that observed by Galileo SC through a violet filter "the filamentary dark features. . . are here revealed to be composed of several dark nodules, like beads on a string, each about 60 miles across" (PIA00072). Actually all Venus' disc seen from a distance ~1.7mln.miles is peppered with these fine features seen on a limit of resolution. So, the Venus' atmosphere has two main frequencies in the solar system with corresponding wave granulations: around Sun 1/225 days (granule πR/6) and around Venus 1/ 4 days (granule πR/338). As was done for the Moon, Phobos, Titan and other icy satellites of Saturn [2, 3, 4 & others] one can apply the wave modulation technique also for the atmosphere of Venus. The lower frequency modulates the higher one by dividing and multiplying it thus getting two side frequencies and corresponding them wave granule sizes. (1/338 : 1/6)πR = πR/56.3 = 342 km. (1/338 x 1/6)πR = πR/2028 = 9.5 km. The larger granules as well arranged network were seen in the near IR Galileo image PIA00073 (several miles below the visible cloud tops). The smaller granules, hopefully, will be detected by the Venus Express cameras. So, the wave planetology applying wave methods to solid planetary bodies and to surrounding them gaseous envelopes shows their structural unity. This understanding may help to analyze and predict very complex behavior of atmospheric sells at Earth (anticyclones up to 5000 km across or πR/4), other planets and Titan. Long time ago known the solar supergranules about 30000 km across were never fully understood. The comparative wave planetology placing them together with wave features of planets and satellites throws light on their origin and behavior and thus expands into an area of the solar physics. In this respect it is interesting to note that rather typical for Sun radio emission in 1 meter diapason also was never properly explained. But applying modulation of the solar photosphere frequency 1/ 1month by the Galaxy frequency 1/ 200 000 000 y. one can obtain such short waves [5]. Radio emissions of planets of the solar system also can be related to this modulation by Galaxy rotation [5]. References: [1] Kochemasov G.G. (1992) Comparison of blob tectonics (Venus) and pair tectonics (Earth) // LPS XXIII, Houston, LPI, pt. 2, 703-704; [2] Kochemasov G.G. (2000) Orbiting frequency modulation in Solar system and its imprint in shapes and structures of celestial bodies // Vernadsky-Brown microsymposium 32 on Comparative planetology, Oct. 9-11, 2000, Moscow, Russia, Abstracs, 88-89; [3] Kochemasov G.G. (2000) Titan: frequency modulation of warping waves // Geophys. Res. Abstr., v. 2, (CD-ROM); [4] Kochemasov G.G. (2005) Cassini' lessons: square craters, shoulderto- shoulder even-size aligned and in grids craters having wave interference nature must be taken out of an impact craters statistics to make it real // Vernadsky-Brown microsymposium-42 "Topics in Comparative Planetology", Oct. 10-12, 2005, Vernadsky Inst., Moscow, Russia, Abstr. m42_31, CD-ROM; [5] Kochemasov G.G. (2001) Inertia-gravity waves of various scales on celestial bodies surfaces, in vertical section and their relation to radiowaves // 34thVernadsky-Brown microsymposium 'Topics in comparative planetology", Moscow, Vernadsky Inst., Abstr., CD-ROM.

Second Venus spacecraft set for launch

NASA Technical Reports Server (NTRS)

1978-01-01

The launch phase of the Pioneer Venus Multiprobe spacecraft and cruise phases of both the Pioneer Venus Orbiter and the Multiprobe spacecraft are covered. Material pertinent to the Venus encounter is included.

Topography of Venus and earth - A test for the presence of plate tectonics

NASA Technical Reports Server (NTRS)

Head, J. W.; Yuter, S. E.; Solomon, S. C.

1981-01-01

Comparisons of earth and Venus topography by use of Pioneer/Venus radar altimetry are examined. Approximately 93% of the Venus surface has been mapped with a horizontal resolution of 200 km and a vertical resolution of 200 m. Tectonic troughs have been indicated in plains regions which cover 65% of Venus, and hypsometric comparisons between the two planets' elevation distributions revealed that while the earth has a bimodal height distribution, Venus displays a unimodal configuration, with 60% of the planet surface within 500 m of the modal planet radius. The effects of mapping the earth at the same resolution as the Venus observations were explored. Continents and oceans were apparent, and although folded mountains appeared as high spots, no indications of tectonic activity were discernible. A NASA Venus Orbiting Imaging radar is outlined, which is designed to detect volcanoes, folded mountain ranges, craters, and faults, and thereby allow definition of possible plate-tectonic activity on Venus.

Chemistry of the surface and lower atmosphere of Venus

NASA Technical Reports Server (NTRS)

Fegley, B., Jr.; Treiman, A.

1992-01-01

A comprehensive overview of the chemical interactions between the atmosphere and surface of Venus is presented. Earth-based, earth-orbital, and spacecraft data on the composition of the atmosphere and surface of Venus are presented and applied to quantitative evaluations of the chemical interactions between carbon, hydrogen, sulfur, chlorine, fluorine, and nitrogen-containing gases and possible minerals on the Venus surface. The calculation results are used to predict stable minerals and mineral assemblages on the Venus surface to determine which, if any, atmospheric gases are buffered by mineral assemblages on the surface, and to critically review and assess prior work on atmosphere-surface chemistry on Venus. It is concluded that the CO2 pressure on Venus is comparable to the CO2 equilibrium partial pressure developed by the calcite + wollastonite + quartz assemblage at the mean Venus surface temperature of 740 K.

Television monitor field shifter and an opto-electronic method for obtaining a stereo image of optimal depth resolution and reduced depth distortion on a single screen

NASA Technical Reports Server (NTRS)

Diner, Daniel B. (Inventor)

1989-01-01

A method and apparatus is developed for obtaining a stereo image with reduced depth distortion and optimum depth resolution. Static and dynamic depth distortion and depth resolution tradeoff is provided. Cameras obtaining the images for a stereo view are converged at a convergence point behind the object to be presented in the image, and the collection-surface-to-object distance, the camera separation distance, and the focal lengths of zoom lenses for the cameras are all increased. Doubling the distances cuts the static depth distortion in half while maintaining image size and depth resolution. Dynamic depth distortion is minimized by panning a stereo view-collecting camera system about a circle which passes through the convergence point and the camera's first nodal points. Horizontal field shifting of the television fields on a television monitor brings both the monitor and the stereo views within the viewer's limit of binocular fusion.

Development of an omnidirectional gamma-ray imaging Compton camera for low-radiation-level environmental monitoring

NASA Astrophysics Data System (ADS)

Watanabe, Takara; Enomoto, Ryoji; Muraishi, Hiroshi; Katagiri, Hideaki; Kagaya, Mika; Fukushi, Masahiro; Kano, Daisuke; Satoh, Wataru; Takeda, Tohoru; Tanaka, Manobu M.; Tanaka, Souichi; Uchida, Tomohisa; Wada, Kiyoto; Wakamatsu, Ryo

2018-02-01

We have developed an omnidirectional gamma-ray imaging Compton camera for environmental monitoring at low levels of radiation. The camera consisted of only six CsI(Tl) scintillator cubes of 3.5 cm, each of which was readout by super-bialkali photo-multiplier tubes (PMTs). Our camera enables the visualization of the position of gamma-ray sources in all directions (∼4π sr) over a wide energy range between 300 and 1400 keV. The angular resolution (σ) was found to be ∼11°, which was realized using an image-sharpening technique. A high detection efficiency of 18 cps/(µSv/h) for 511 keV (1.6 cps/MBq at 1 m) was achieved, indicating the capability of this camera to visualize hotspots in areas with low-radiation-level contamination from the order of µSv/h to natural background levels. Our proposed technique can be easily used as a low-radiation-level imaging monitor in radiation control areas, such as medical and accelerator facilities.

On ion escape from Venus

NASA Astrophysics Data System (ADS)

Jarvinen, R.

2011-04-01

This doctoral thesis is about the solar wind influence on the atmosphere of the planet Venus. A numerical plasma simulation model was developed for the interaction between Venus and the solar wind to study the erosion of charged particles from the Venus upper atmosphere. The developed model is a hybrid simulation where ions are treated as particles and electrons are modelled as a fluid. The simulation was used to study the solar wind induced ion escape from Venus as observed by the European Space Agency's Venus Express and NASA's Pioneer Venus Orbiter spacecraft. Especially, observations made by the ASPERA-4 particle instrument onboard Venus Express were studied. The thesis consists of an introductory part and four peer-reviewed articles published in scientific journals. In the introduction Venus is presented as one of the terrestrial planets in the Solar System and the main findings of the work are discussed within the wider context of planetary physics.Venus is the closest neighbouring planet to the Earth and the most earthlike planet in its size and mass orbiting the Sun. Whereas the atmosphere of the Earth consists mainly of nitrogen and oxygen, Venus has a hot carbon dioxide atmosphere, which is dominated by the greenhouse effect. Venus has all of its water in the atmosphere, which is only a fraction of the Earth's total water supply. Since planets developed presumably in similar conditions in the young Solar System, why Venus and Earth became so different in many respects?One important feature of Venus is that the planet does not have an intrinsic magnetic field. This makes it possible for the solar wind, a continuous stream of charged particles from the Sun, to flow close to Venus and to pick up ions from the planet's upper atmosphere. The strong intrinsic magnetic field of the Earth dominates the terrestrial magnetosphere and deflects the solar wind flow far away from the atmosphere. The region around Venus where the planet's atmosphere interacts with the solar wind is called the plasma environment or the induced magnetosphere.Main findings of the work include new knowledge about the movement of escaping planetary ions in the Venusian induced magnetosphere. Further, the developed simulation model was used to study how the solar wind conditions affect the ion escape from Venus. Especially, the global three-dimensional structure of the Venusian particle and magnetic environment was studied. The results help to interpret spacecraft observations around the planet. Finally, several remaining questions were identified, which could potentially improve our knowledge of the Venus ion escape and guide the future development of planetary plasma simulations.

On ion escape from Venus

NASA Astrophysics Data System (ADS)

Jarvinen, Riku

2011-04-01

This doctoral thesis is about the solar wind influence on the atmosphere of the planet Venus. A numerical plasma simulation model was developed for the interaction between Venus and the solar wind to study the erosion of charged particles from the Venus upper atmosphere. The developed model is a hybrid simulation where ions are treated as particles and electrons are modelled as a fluid. The simulation was used to study the solar wind induced ion escape from Venus as observed by the European Space Agency's Venus Express and NASA's Pioneer Venus Orbiter spacecraft. Especially, observations made by the ASPERA-4 particle instrument onboard Venus Express were studied. The thesis consists of an introductory part and four peer-reviewed articles published in scientific journals. In the introduction Venus is presented as one of the terrestrial planets in the Solar System and the main findings of the work are discussed within the wider context of planetary physics. Venus is the closest neighbouring planet to the Earth and the most earthlike planet in its size and mass orbiting the Sun. Whereas the atmosphere of the Earth consists mainly of nitrogen and oxygen, Venus has a hot carbon dioxide atmosphere, which is dominated by the greenhouse effect. Venus has all of its water in the atmosphere, which is only a fraction of the Earth's total water supply. Since planets developed presumably in similar conditions in the young Solar System, why Venus and Earth became so different in many respects? One important feature of Venus is that the planet does not have an intrinsic magnetic field. This makes it possible for the solar wind, a continuous stream of charged particles from the Sun, to flow close to Venus and to pick up ions from the planet's upper atmosphere. The strong intrinsic magnetic field of the Earth dominates the terrestrial magnetosphere and deflects the solar wind flow far away from the atmosphere. The region around Venus where the planet's atmosphere interacts with the solar wind is called the plasma environment or the induced magnetosphere. Main findings of the work include new knowledge about the movement of escaping planetary ions in the Venusian induced magnetosphere. Further, the developed simulation model was used to study how the solar wind conditions affect the ion escape from Venus. Especially, the global three-dimensional structure of the Venusian particle and magnetic environment was studied. The results help to interpret spacecraft observations around the planet. Finally, several remaining questions were identified, which could potentially improve our knowledge of the Venus ion escape and guide the future development of planetary plasma simulations.

Future Exploration of Venus

NASA Astrophysics Data System (ADS)

Limaye, Sanjay

Venus has been the target of exploration for half a century, before the successful Mariner 2 fly-by in December 1962. The decade after that was marked by growing sophistication in the instruments and spacecraft. During the second decade of Venus exploration (1972 - 1981) the instruments and spacecraft had advanced to make the first detailed survey of the planet and image the surface. During the third decade Venus was explored with more advanced instruments such as synthetic aperture radar and by balloons - the only balloons in another atmosphere ever flown till present. Then came a long pause until 2005 when ESA launched Venus Express, which is still orbiting the planet and returning data. The nearly two-dozen missions flown to Venus have painted a puzzling picture of Venus - we still do not have answers to some key questions. The foremost is why did Venus evolve so differently from Earth? International space agencies and scientists have been considering various approaches to exploring Venus through small and large missions. The Venus Exploration Analysis Group (NASA) has developed a Venus Exploration Roadmap and a comprehensive list of goals, objectives and investigations (www.lpi.usra.edu/vexag), but an international coordinated, comprehensive plan to explore Venus is needed. To fill this void, the COSPAR International Venus Exploration Working Group (IVEWG) has been active in fostering dialog and discussions among the space faring agencies. One small step in the future exploration of Venus is the formation of a joint Science Definition Team (SDT) (NASA and Roscosmos/IKI) for Russia’s Venera-D mission in early 2014. The team is expected to submit a report to respective agencies in early 2015. Towards identifying key surface regions and atmospheric regions of Venus, a workshop is being held in May 2014 by VEXAG to seek community input. It is likely that calls for proposals for missions will also be announced under the M class by ESA and under the Discovery Program by NASA during 2014. Given that the science questions about Venus are many - ranging from the surface and interior and extending into the atmosphere to 120 km and beyond, it is likely that there will be opportunities for other efforts to contribute to the comprehensive exploration of Venus. If undertaken in a coordinated and collaborative manner, we may make substantial progress in understanding Venus, why and/or how it evolved differently from Earth. This knowledge will help us understand Earth-like rocky planets around other stars that are being discovered at a rapid pace now.

A novel camera localization system for extending three-dimensional digital image correlation

NASA Astrophysics Data System (ADS)

Sabato, Alessandro; Reddy, Narasimha; Khan, Sameer; Niezrecki, Christopher

2018-03-01

The monitoring of civil, mechanical, and aerospace structures is important especially as these systems approach or surpass their design life. Often, Structural Health Monitoring (SHM) relies on sensing techniques for condition assessment. Advancements achieved in camera technology and optical sensors have made three-dimensional (3D) Digital Image Correlation (DIC) a valid technique for extracting structural deformations and geometry profiles. Prior to making stereophotogrammetry measurements, a calibration has to be performed to obtain the vision systems' extrinsic and intrinsic parameters. It means that the position of the cameras relative to each other (i.e. separation distance, cameras angle, etc.) must be determined. Typically, cameras are placed on a rigid bar to prevent any relative motion between the cameras. This constraint limits the utility of the 3D-DIC technique, especially as it is applied to monitor large-sized structures and from various fields of view. In this preliminary study, the design of a multi-sensor system is proposed to extend 3D-DIC's capability and allow for easier calibration and measurement. The suggested system relies on a MEMS-based Inertial Measurement Unit (IMU) and a 77 GHz radar sensor for measuring the orientation and relative distance of the stereo cameras. The feasibility of the proposed combined IMU-radar system is evaluated through laboratory tests, demonstrating its ability in determining the cameras position in space for performing accurate 3D-DIC calibration and measurements.

A high-speed trapezoid image sensor design for continuous traffic monitoring at signalized intersection approaches.

DOT National Transportation Integrated Search

2014-10-01

The goal of this project is to monitor traffic flow continuously with an innovative camera system composed of a custom : designed image sensor integrated circuit (IC) containing trapezoid pixel array and camera system that is capable of : intelligent...

Camera Traps on Wildlife Crossing Structures as a Tool in Gray Wolf (Canis lupus) Management - Five-Years Monitoring of Wolf Abundance Trends in Croatia

PubMed Central

Križan, Josip; Gužvica, Goran

2016-01-01

The conservation of gray wolf (Canis lupus) and its coexistence with humans presents a challenge and requires continuous monitoring and management efforts. One of the non-invasive methods that produces high-quality wolf monitoring datasets is camera trapping. We present a novel monitoring approach where camera traps are positioned on wildlife crossing structures that channel the animals, thereby increasing trapping success and increasing the cost-efficiency of the method. In this way we have followed abundance trends of five wolf packs whose home ranges are intersected by a motorway which spans throughout the wolf distribution range in Croatia. During the five-year monitoring of six green bridges we have recorded 28 250 camera-events, 132 with wolves. Four viaducts were monitored for two years, recording 4914 camera-events, 185 with wolves. We have detected a negative abundance trend of the monitored Croatian wolf packs since 2011, especially severe in the northern part of the study area. Further, we have pinpointed the legal cull as probable major negative influence on the wolf pack abundance trends (linear regression, r2 > 0.75, P < 0.05). Using the same approach we did not find evidence for a negative impact of wolves on the prey populations, both wild ungulates and livestock. We encourage strict protection of wolf in Croatia until there is more data proving population stability. In conclusion, quantitative methods, such as the one presented here, should be used as much as possible when assessing wolf abundance trends. PMID:27327498

Camera Traps on Wildlife Crossing Structures as a Tool in Gray Wolf (Canis lupus) Management - Five-Years Monitoring of Wolf Abundance Trends in Croatia.

PubMed

Šver, Lidija; Bielen, Ana; Križan, Josip; Gužvica, Goran

2016-01-01

The conservation of gray wolf (Canis lupus) and its coexistence with humans presents a challenge and requires continuous monitoring and management efforts. One of the non-invasive methods that produces high-quality wolf monitoring datasets is camera trapping. We present a novel monitoring approach where camera traps are positioned on wildlife crossing structures that channel the animals, thereby increasing trapping success and increasing the cost-efficiency of the method. In this way we have followed abundance trends of five wolf packs whose home ranges are intersected by a motorway which spans throughout the wolf distribution range in Croatia. During the five-year monitoring of six green bridges we have recorded 28 250 camera-events, 132 with wolves. Four viaducts were monitored for two years, recording 4914 camera-events, 185 with wolves. We have detected a negative abundance trend of the monitored Croatian wolf packs since 2011, especially severe in the northern part of the study area. Further, we have pinpointed the legal cull as probable major negative influence on the wolf pack abundance trends (linear regression, r2 > 0.75, P < 0.05). Using the same approach we did not find evidence for a negative impact of wolves on the prey populations, both wild ungulates and livestock. We encourage strict protection of wolf in Croatia until there is more data proving population stability. In conclusion, quantitative methods, such as the one presented here, should be used as much as possible when assessing wolf abundance trends.

Can camera traps monitor Komodo dragons a large ectothermic predator?

PubMed

Ariefiandy, Achmad; Purwandana, Deni; Seno, Aganto; Ciofi, Claudio; Jessop, Tim S

2013-01-01

Camera trapping has greatly enhanced population monitoring of often cryptic and low abundance apex carnivores. Effectiveness of passive infrared camera trapping, and ultimately population monitoring, relies on temperature mediated differences between the animal and its ambient environment to ensure good camera detection. In ectothermic predators such as large varanid lizards, this criterion is presumed less certain. Here we evaluated the effectiveness of camera trapping to potentially monitor the population status of the Komodo dragon (Varanus komodoensis), an apex predator, using site occupancy approaches. We compared site-specific estimates of site occupancy and detection derived using camera traps and cage traps at 181 trapping locations established across six sites on four islands within Komodo National Park, Eastern Indonesia. Detection and site occupancy at each site were estimated using eight competing models that considered site-specific variation in occupancy (ψ)and varied detection probabilities (p) according to detection method, site and survey number using a single season site occupancy modelling approach. The most parsimonious model [ψ (site), p (site survey); ω = 0.74] suggested that site occupancy estimates differed among sites. Detection probability varied as an interaction between site and survey number. Our results indicate that overall camera traps produced similar estimates of detection and site occupancy to cage traps, irrespective of being paired, or unpaired, with cage traps. Whilst one site showed some evidence detection was affected by trapping method detection was too low to produce an accurate occupancy estimate. Overall, as camera trapping is logistically more feasible it may provide, with further validation, an alternative method for evaluating long-term site occupancy patterns in Komodo dragons, and potentially other large reptiles, aiding conservation of this species.

Can Camera Traps Monitor Komodo Dragons a Large Ectothermic Predator?

PubMed Central

Ariefiandy, Achmad; Purwandana, Deni; Seno, Aganto; Ciofi, Claudio; Jessop, Tim S.

2013-01-01

Camera trapping has greatly enhanced population monitoring of often cryptic and low abundance apex carnivores. Effectiveness of passive infrared camera trapping, and ultimately population monitoring, relies on temperature mediated differences between the animal and its ambient environment to ensure good camera detection. In ectothermic predators such as large varanid lizards, this criterion is presumed less certain. Here we evaluated the effectiveness of camera trapping to potentially monitor the population status of the Komodo dragon (Varanus komodoensis), an apex predator, using site occupancy approaches. We compared site-specific estimates of site occupancy and detection derived using camera traps and cage traps at 181 trapping locations established across six sites on four islands within Komodo National Park, Eastern Indonesia. Detection and site occupancy at each site were estimated using eight competing models that considered site-specific variation in occupancy (ψ)and varied detection probabilities (p) according to detection method, site and survey number using a single season site occupancy modelling approach. The most parsimonious model [ψ (site), p (site*survey); ω = 0.74] suggested that site occupancy estimates differed among sites. Detection probability varied as an interaction between site and survey number. Our results indicate that overall camera traps produced similar estimates of detection and site occupancy to cage traps, irrespective of being paired, or unpaired, with cage traps. Whilst one site showed some evidence detection was affected by trapping method detection was too low to produce an accurate occupancy estimate. Overall, as camera trapping is logistically more feasible it may provide, with further validation, an alternative method for evaluating long-term site occupancy patterns in Komodo dragons, and potentially other large reptiles, aiding conservation of this species. PMID:23527027

Use of a color CMOS camera as a colorimeter

NASA Astrophysics Data System (ADS)

Dallas, William J.; Roehrig, Hans; Redford, Gary R.

2006-08-01

In radiology diagnosis, film is being quickly replaced by computer monitors as the display medium for all imaging modalities. Increasingly, these monitors are color instead of monochrome. It is important to have instruments available to characterize the display devices in order to guarantee reproducible presentation of image material. We are developing an imaging colorimeter based on a commercially available color digital camera. The camera uses a sensor that has co-located pixels in all three primary colors.

Missions to Venus

NASA Astrophysics Data System (ADS)

Titov, D. V.; Baines, K. H.; Basilevsky, A. T.; Chassefiere, E.; Chin, G.; Crisp, D.; Esposito, L. W.; Lebreton, J.-P.; Lellouch, E.; Moroz, V. I.; Nagy, A. F.; Owen, T. C.; Oyama, K.-I.; Russell, C. T.; Taylor, F. W.; Young, R. E.

2002-10-01

Venus has always been a fascinating objective for planetary studies. At the beginning of the space era Venus became one of the first targets for spacecraft missions. Our neighbour in the solar system and, in size, the twin sister of Earth, Venus was expected to be very similar to our planet. However, the first phase of Venus spacecraft exploration in 1962-1992 by the family of Soviet Venera and Vega spacecraft and US Mariner, Pioneer Venus, and Magellan missions discovered an entirely different, exotic world hidden behind a curtain of dense clouds. These studies gave us a basic knowledge of the conditions on the planet, but generated many more questions concerning the atmospheric composition, chemistry, structure, dynamics, surface-atmosphere interactions, atmospheric and geological evolution, and the plasma environment. Despite all of this exploration by more than 20 spacecraft, the "morning star" still remains a mysterious world. But for more than a decade Venus has been a "forgotten" planet with no new missions featuring in the plans of the world space agencies. Now we are witnessing the revival of interest in this planet: the Venus Orbiter mission is approved in Japan, Venus Express - a European orbiter mission - has successfully passed the selection procedure in ESA, and several Venus Discovery proposals are knocking at the doors of NASA. The paper presents an exciting story of Venus spacecraft exploration, summarizes open scientific problems, and builds a bridge to the future missions.

Exploring Venus: the Venus Exploration Analysis Group (VEXAG)

NASA Astrophysics Data System (ADS)

Ocampo, A.; Atreya, S.; Thompson, T.; Luhmann, J.; Mackwell, S.; Baines, K.; Cutts, J.; Robinson, J.; Saunders, S.

In July 2005 NASA s Planetary Division established the Venus Exploration Analysis Group VEXAG http www lpi usra edu vexag in order to engage the scientific community at large in identifying scientific priorities and strategies for the exploration of Venus VEXAG is a community-based forum open to all interested in the exploration of Venus VEXAG was designed to provide scientific input and technology development plans for planning and prioritizing the study of Venus over the next several decades including a Venus surface sample return VEXAG regularly evaluates NASA s Venus exploration goals scientific objectives investigations and critical measurement requirements including the recommendations in the National Research Council Decadal Survey and NASA s Solar System Exploration Strategic Roadmap VEXAG will take into consideration the latest scientific results from ESA s Venus Express mission and the MESSENGER flybys as well as the results anticipated from JAXA s Venus Climate Orbiter together with science community inputs from venues such as the February 13-16 2006 AGU Chapman Conference to identify the scientific priorities and strategies for future NASA Venus exploration VEXAG is composed of two co-chairs Sushil Atreya University of Michigan Ann Arbor and Janet Luhmann University of California Berkeley VEXAG has formed three focus groups in the areas of 1 Planetary Formation and Evolution Surface and Interior Volcanism Geodynamics etc Focus Group Lead Steve Mackwell LPI 2 Atmospheric Evolution Dynamics Meteorology

ARC-1978-AC78-9464

NASA Image and Video Library

1978-03-20

Graphic Art Venus - Day - Night drawing showing solar wind, bow shock, magnetosheath, clouds and streamers Pioneer Venus SP-461 fig 6-28 Interaction of the solar wind with the atmosphere of Venus as termined from Pioner Venus experiments and observations

Stereoscopic Configurations To Minimize Distortions

NASA Technical Reports Server (NTRS)

Diner, Daniel B.

1991-01-01

Proposed television system provides two stereoscopic displays. Two-camera, two-monitor system used in various camera configurations and with stereoscopic images on monitors magnified to various degrees. Designed to satisfy observer's need to perceive spatial relationships accurately throughout workspace or to perceive them at high resolution in small region of workspace. Potential applications include industrial, medical, and entertainment imaging and monitoring and control of telemanipulators, telerobots, and remotely piloted vehicles.

Venus Atmospheric Exploration by Solar Aircraft

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A.; LaMarre, C.; Colozza, A.

2002-01-01

The Venus atmosphere is a favorable environment for flying powered aircraft. The atmospheric pressure makes flight much easier than on planets such as Mars. Above the clouds, solar energy is available in abundance on Venus, and the slow rotation of Venus allows a solar airplane to be designed for flight within continuous sunlight. The atmosphere between 50 km and 75 km on Venus is one of the most dynamic and interesting regions of the planet. The challenge for a Venus aircraft will be the fierce winds and caustic atmosphere. In order to remain on the sunlit side of Venus, an exploration aircraft will have to be capable of sustained flight at or above the wind speed. An aircraft would be a powerful tool for exploration. By learning how Venus can be so similar to Earth, and yet so different, we will learn to better understand the climate and geological history of the Earth.

a Spatio-Spectral Camera for High Resolution Hyperspectral Imaging

NASA Astrophysics Data System (ADS)

Livens, S.; Pauly, K.; Baeck, P.; Blommaert, J.; Nuyts, D.; Zender, J.; Delauré, B.

2017-08-01

Imaging with a conventional frame camera from a moving remotely piloted aircraft system (RPAS) is by design very inefficient. Less than 1 % of the flying time is used for collecting light. This unused potential can be utilized by an innovative imaging concept, the spatio-spectral camera. The core of the camera is a frame sensor with a large number of hyperspectral filters arranged on the sensor in stepwise lines. It combines the advantages of frame cameras with those of pushbroom cameras. By acquiring images in rapid succession, such a camera can collect detailed hyperspectral information, while retaining the high spatial resolution offered by the sensor. We have developed two versions of a spatio-spectral camera and used them in a variety of conditions. In this paper, we present a summary of three missions with the in-house developed COSI prototype camera (600-900 nm) in the domains of precision agriculture (fungus infection monitoring in experimental wheat plots), horticulture (crop status monitoring to evaluate irrigation management in strawberry fields) and geology (meteorite detection on a grassland field). Additionally, we describe the characteristics of the 2nd generation, commercially available ButterflEYE camera offering extended spectral range (475-925 nm), and we discuss future work.

VICI (Venus In Situ Composition Investigations): The Next Step in Understanding Venus Climate Evolution

NASA Astrophysics Data System (ADS)

Glaze, L. S.; Garvin, J. B.

2017-12-01

Venus provides a natural laboratory to explore an example of terrestrial planet evolution that may be cosmically ubiquitous. By better understanding the composition of the Venus atmosphere and surface, we can better constrain the efficiency of the Venusian greenhouse. VICI is a proposed NASA New Frontiers mission that delivers two landers to Venus on two separate Venus fly-bys. Following six orbital remote sensing missions to Venus (since 1978), VICI would be the first mission to land on the Venus surface since 1985, and the first U.S. mission to enter the Venus atmosphere in 49 years. The four major VICI science objectives are: Atmospheric origin and evolution: Understand the origin of the Venus atmosphere, how it has evolved, including how recently Venus lost its oceans, and how and why it is different from the atmospheres of Earth and Mars, through in situ measurements of key noble gases, nitrogen, and hydrogen. Atmospheric composition and structure: Reveal the unknown chemical processes and structure in Venus' deepest atmosphere that dominate the current climate through two comprehensive, in situ vertical profiles. Surface properties and geologic evolution: For the first time ever, explore the tessera from the surface, specifically to test hypotheses of ancient content-building cycles, erosion, and links to past climates using multi-point mineralogy, elemental chemistry, imaging and topography. Surface-atmosphere interactions: Characterize Venus' surface weathering environment and provide insight into the sulfur cycle at the surface-atmosphere interface by integrating rich atmospheric composition and structure datasets with imaging, surface mineralogy, and elemental rock composition. VICI is designed to study Venus' climate history through detailed atmospheric composition measurements not possible on earlier missions. In addition, VICI images the tessera surface during descent enabling detailed topography to be generated. Finally, VICI makes multiple elemental chemistry measurements, including depth profiles through the weathering rind and subsurface, and the first ever direct mineralogy measurements on the Venus surface. VICI's payloads build on the success of the Mars Science Laboratory (MSL) by carrying the same instrumentation that has delivered high-impact science results on Mars.

Regional tectonic analysis of Venus equatorial highlands and comparison with Earth-based Magellan radar images

NASA Technical Reports Server (NTRS)

Williams, David R.; Wetherill, George

1993-01-01

Research on regional tectonic analysis of Venus equatorial highlands and comparison with earth-based and Magellan radar images is presented. Over the past two years, the tectonic analysis of Venus performed centered on global properties of the planet, in order to understand fundamental aspects of the dynamics of the mantle and lithosphere of Venus. These include studies pertaining to the original constitutive and thermal character of the planet, as well as the evolution of Venus through time, and the present day tectonics. Parameterized convection models of the Earth and Venus were developed. The parameterized convection code was reformulated to model Venus with an initially hydrous mantle to determine how the cold-trap could affect the evolution of the planet.

Modeling of atmospheric-coupled Rayleigh waves on planets with atmosphere: From Earth observation to Mars and Venus perspectives.

PubMed

Lognonné, Philippe; Karakostas, Foivos; Rolland, Lucie; Nishikawa, Yasuhiro

2016-08-01

Acoustic coupling between solid Earth and atmosphere has been observed since the 1960s, first from ground-based seismic, pressure, and ionospheric sensors and since 20 years with various satellite measurements, including with global positioning system (GPS) satellites. This coupling leads to the excitation of the Rayleigh surface waves by local atmospheric sources such as large natural explosions from volcanoes, meteor atmospheric air-bursts, or artificial explosions. It contributes also in the continuous excitation of Rayleigh waves and associated normal modes by atmospheric winds and pressure fluctuations. The same coupling allows the observation of Rayleigh waves in the thermosphere most of the time through ionospheric monitoring with Doppler sounders or GPS. The authors review briefly in this paper observations made on Earth and describe the general frame of the theory enabling the computation of Rayleigh waves for models of telluric planets with atmosphere. The authors then focus on Mars and Venus and give in both cases the atmospheric properties of the Rayleigh normal modes and associated surface waves compared to Earth. The authors then conclude on the observation perspectives especially for Rayleigh waves excited by atmospheric sources on Mars and for remote ionospheric observations of Rayleigh waves excited by quakes on Venus.

ESA to present the latest Venus Express results to the media

NASA Astrophysics Data System (ADS)

2007-11-01

The launch of Venus Express back in November 2005 represented a major milestone in the exploration of Venus — a planet unvisited by any dedicated spacecraft since the early 1990s. One of the fundamental questions being addressed by the Venus Express mission is why a world so similar to Earth in mass and size has evolved so differently, to become the noxious and inhospitable planet it is today. Since it started its scientific observations in July 2006, Venus Express has been making the most detailed study of the planet’s thick and complex atmosphere to date. The latest findings not only highlight the features that make Venus unique in the solar system but also provide fresh clues as to how the planet is — despite everything — a more Earth-like planetary neighbour than one could have imagined. The results will appear in a special section of the 29 November issue of the journal Nature containing nine individual papers devoted to Venus Express science activities. Media organisations interested in attending the press conference are invited to register via the form attached below. Media that cannot attend will have the opportunity to follow the press conference via the following phone line: +33 1 58 99 57 42 (listening-mode only).The results presented at the press conference are embargoed until 28 November 19:00 CET. For more information ESA Media Relations Office Tel: +33 1 5369 7299 Fax: +33 1 5369 7690 Media event programme ‘Venus: a more Earth-like planetary neighbour’ Latest results from Venus Express 28 November 2007, 15:00, room 137 ESA Headquarters, 8-10 rue Mario-Nikis, Paris 15:00 Introduction, by Håkan Svedhem, ESA Venus Express Project Scientist 15:07 Venus: What we knew before, by Fred Taylor, Venus Express Interdisciplinary Scientist 15:15 Temperatures in the atmosphere of Venus, by Jean-Loup Bertaux, SPICAV Principal Investigator 15:25 The dynamic atmosphere of Venus, by Giuseppe Piccioni, VIRTIS Principal Investigator 15:40 Venus’s atmosphere and the solar wind, by Stas Barabash, ASPERA Principal Investigator 15:50 Climate and evolution, by David Grinspoon, Venus Express Interdisciplinary Scientist 16:00 Conclusion, by Dmitri Titov, Venus Express Science Coordinator and VMC scientist 16:05 Questions and Answers 16:25 Individual interviews 17:30 End of event

Robotic Technology for Exploration of Venus

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A.

2003-01-01

Venus, the "greenhouse planet", is a scientifically fascinating place. A huge number of important scientific questions remain to be answered. Venus is sometimes called Earth's "sister planet" due to the fact that it is closest to the Earth in distance and similar to Earth in size. Despite its similarity to Earth, however, the climate of Venus is vastly different from Earth's. Understanding the atmosphere, climate, geology, and history of Venus could shed considerable light on our understanding of our own home planet. The surface of Venus is a hostile environment, with an atmosperic pressure of over 90 bar of carbon dioxide, temperature of 450 C, and shrouded in sulphuric-acid clouds. Venus has been explored by a number of missions from Earth, including the Russian Venera missions which landed probes on the surface, the American Pioneer missions which flew both orbiters and atmospheric probes to Venus, the Russian "Vega" mission, which floated balloons in the atmosphere of Venus, and most recently the American Magellan mission which mapped the surface by radar imaging. While these missions have answered basic questions about Venus, telling us the surface temperature and pressure, the elevations and topography of the continents, and the composition of the atmosphere and clouds, scientific mysteries still abound. Venus is of considerable interest to terrestrial atmospheric science, since of all the planets in the solar system, it is the closest analogue to the Earth in terms of atmosphere. Yet Venus' atmosphere is an example of "runaway greenhouse effect." Understanding the history and the dynamics of Venus' atmosphere could tell us considerable insight about the workings of the atmosphere of the Earth. It also has some interest to astrobiology-- could life have existed on Venus in an earlier, pre-greenhouse-effect phase? Could life still be possible in the temperate middle-atmosphere of Venus? The geology of Venus also has interest in the study of Earth. surface robot will require new technologies; specifically, it will require electronics, scientific instruments, power supplies, and mechanical linkages designed to operate at a temperature above 450 C-hot enough to melt the solder on a standard electronic circuit board. This will require devices made from advanced semiconductor materials, such as silicon carbide, or even new approaches, such as micro-vacuum tube electronics. Such materials are now being developed in the laboratory.

HAVOC: High Altitude Venus Operational Concept - An Exploration Strategy for Venus

NASA Technical Reports Server (NTRS)

Arney, Dale; Jones, Chris

2015-01-01

The atmosphere of Venus is an exciting destination for both further scientific study and future human exploration. A lighter-than-air vehicle can carry either a host of instruments and probes, or a habitat and ascent vehicle for a crew of two astronauts to explore Venus for up to a month. The mission requires less time to complete than a crewed Mars mission, and the environment at 50 km is relatively benign, with similar pressure, density, gravity, and radiation protection to the surface of Earth. A recent internal NASA study of a High Altitude Venus Operational Concept (HAVOC) led to the development of an evolutionary program for the exploration of Venus, with focus on the mission architecture and vehicle concept for a 30 day crewed mission into Venus's atmosphere. Key technical challenges for the mission include performing the aerocapture maneuvers at Venus and Earth, inserting and inflating the airship at Venus, and protecting the solar panels and structure from the sulfuric acid in the atmosphere. With advances in technology and further refinement of the concept, missions to the Venusian atmosphere can expand humanity's future in space.

Development of an all-in-one gamma camera/CCD system for safeguard verification

NASA Astrophysics Data System (ADS)

Kim, Hyun-Il; An, Su Jung; Chung, Yong Hyun; Kwak, Sung-Woo

2014-12-01

For the purpose of monitoring and verifying efforts at safeguarding radioactive materials in various fields, a new all-in-one gamma camera/charged coupled device (CCD) system was developed. This combined system consists of a gamma camera, which gathers energy and position information on gamma-ray sources, and a CCD camera, which identifies the specific location in a monitored area. Therefore, 2-D image information and quantitative information regarding gamma-ray sources can be obtained using fused images. A gamma camera consists of a diverging collimator, a 22 × 22 array CsI(Na) pixelated scintillation crystal with a pixel size of 2 × 2 × 6 mm3 and Hamamatsu H8500 position-sensitive photomultiplier tube (PSPMT). The Basler scA640-70gc CCD camera, which delivers 70 frames per second at video graphics array (VGA) resolution, was employed. Performance testing was performed using a Co-57 point source 30 cm from the detector. The measured spatial resolution and sensitivity were 4.77 mm full width at half maximum (FWHM) and 7.78 cps/MBq, respectively. The energy resolution was 18% at 122 keV. These results demonstrate that the combined system has considerable potential for radiation monitoring.

Radiative transfer modeling for analyses with Akatsuki/IR2 images

NASA Astrophysics Data System (ADS)

Sato, Takao M.; Satoh, Takehiko; Hashimoto, George L.; Lee, Yeon Joo; Sagawa, Hideo; Kasaba, Yasumasa

2017-10-01

The 2-micron camera (IR2) onboard Japanese Venus orbiter, Akatsuki had regularly observed Venus with four narrow-band filters (1.735, 2.02, 2.26, and 2.32 micron) from the late of March, 2016 until the electronic device was unable to control IR2 on December 9, 2016. For approximately nine months, we accumulated more than 3,000 dayside and nightside images of Venus. The main purposes of analyzing IR2 data are (i) to study the dynamics in the upper, middle, and lower atmosphere with the cloud-tracked winds, (ii) to derive the cloud top altitude with the 2.02 micron channel which is located in a CO2 absorption band, (iii) to deduce CO distribution, which is thought to be a good tracer of the atmospheric circulation below the massive clouds, by utilizing the 2.26 and 2.32 micron channels, and (iv) to investigate aerosol properties of the lower clouds with the 1.735 and 2.26 micron channels. For purposes (ii)-(iv), we have developed a line-by-line based radiative transfer model for generating synthetic radiance at the IR2 channels. For both solar and thermal radiation cases, adding doubling method (Hovenier et al., 2004; Liu and Weng, 2006) is selected for solving multiple scattering by clouds and molecules. We considered a total of eight molecules (H2O, CO2, CO, SO2, HF, HCl, OCS, and N2) and line parameters of the first three molecules are taken from HITEMP10 and those of the others are from HITRAN12. For all considered molecules, their line shapes are modelled as Voigt function with cutoff of 125 cm-1. For CO2, additional modification is done based on Tonkov et al. (1996). A cloud model consisting of four modal cloud particles with a mixture of 75% H2SO4 and 25% H2O is taken from Haus et al. (2013). This model was tested from near-infrared to mid-infrared ranges for the spectral analyses of Venus Express and Venera 15 data, which is useful for interpreting the very limited spectral information such as Akatsuki data. In this presentation, we will show the detail of the radiative transfer modeling for analyzing the IR2 data and, as its demonstration, the primitive results of spatiotemporal variations of CO abundance in the lower atmosphere.

Venus Cloud Tops Viewed by Hubble

NASA Image and Video Library

1999-05-18

Venus Cloud Tops Viewed by Hubble. This is a NASA Hubble Space Telescope ultraviolet-light image of the planet Venus, taken on January 24 1995, when Venus was at a distance of 70.6 million miles 113.6 million kilometers from Earth.

Pioneer Venus large probe neutral mass spectrometer

NASA Technical Reports Server (NTRS)

Hoffman, J.

1982-01-01

The deuterium hydrogen abundance ratio in the Venus atmosphere was measured while the inlets to the Pioneer Venus large probe mass spectrometer were coated with sulfuric acid from Venus' clouds. The ratio is (1.6 + or - 0.2) x 10 to the minus two power. It was found that the 100 fold enrichment of deuterium means that Venus outgassed at least 0.3% of a terrestrial ocean and possibly more.

Exploring Venus by Solar Airplane

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A.

2001-01-01

A solar-powered airplane is proposed to explore the atmospheric environment of Venus. Venus has several advantages for a solar airplane. At the top of the cloud level, the solar intensity is comparable to or greater than terrestrial solar intensities. The Earthlike atmospheric pressure means that the power required for flight is lower for Venus than that of Mars, and the slow rotation of Venus allows an airplane to be designed for continuous sunlight, with no energy storage needed for night-time flight. These factors mean that Venus is perhaps the easiest planet in the solar system for flight of a long-duration solar airplane.

Video monitoring system for car seat

NASA Technical Reports Server (NTRS)

Elrod, Susan Vinz (Inventor); Dabney, Richard W. (Inventor)

2004-01-01

A video monitoring system for use with a child car seat has video camera(s) mounted in the car seat. The video images are wirelessly transmitted to a remote receiver/display encased in a portable housing that can be removably mounted in the vehicle in which the car seat is installed.

Improved head-controlled TV system produces high-quality remote image

NASA Technical Reports Server (NTRS)

Goertz, R.; Lindberg, J.; Mingesz, D.; Potts, C.

1967-01-01

Manipulator operator uses an improved resolution tv camera/monitor positioning system to view the remote handling and processing of reactive, flammable, explosive, or contaminated materials. The pan and tilt motions of the camera and monitor are slaved to follow the corresponding motions of the operators head.

Radiation-Triggered Surveillance for UF6 Monitoring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Curtis, Michael M.

2015-12-01

This paper recommends the use of radiation detectors, singly or in sets, to trigger surveillance cameras. Ideally, the cameras will monitor cylinders transiting the process area as well as the process area itself. The general process area will be surveyed to record how many cylinders have been attached and detached to the process between inspections. Rad-triggered cameras can dramatically reduce the quantity of recorded images, because the movement of personnel and equipment not involving UF6 cylinders will not generate a surveillance review file.

Venus Lightning: What We Have Learned from the Venus Express Fluxgate Magnetometer

NASA Astrophysics Data System (ADS)

Russell, C. T.; Strangeway, R. J.; Wei, H. Y.; Zhang, T. L.

2010-03-01

The Venus Express magnetometer sees short (tens of milliseconds) pulses of EM waves in the Venus ionosphere as predicted by the lightning model for the PVO electric pulses. These waves are stronger than similar terrestrial signals produced by lightning.

A Prototype Flux-Plate Heat-Flow Sensor for Venus Surface Heat-Flow Determinations

NASA Technical Reports Server (NTRS)

Morgan, Paul; Reyes, Celso; Smrekar, Suzanne E.

2005-01-01

Venus is the most Earth-like planet in the Solar System in terms of size, and the densities of the two planets are almost identical when selfcompression of the two planets is taken into account. Venus is the closest planet to Earth, and the simplest interpretation of their similar densities is that their bulk compositions are almost identical. Models of the thermal evolution of Venus predict interior temperatures very similar to those indicated for the regions of Earth subject to solid-state convection, but even global analyses of the coarse Pioneer Venus elevation data suggest Venus does not lose heat by the same primary heat loss mechanism as Earth, i.e., seafloor spreading. The comparative paucity of impact craters on Venus has been interpreted as evidence for relatively recent resurfacing of the planet associated with widespread volcanic and tectonic activity. The difference in the gross tectonic styles of Venus and Earth, and the origins of some of the enigmatic volcano-tectonic features on Venus, such as the coronae, appear to be intrinsically related to Venus heat loss mechanism(s). An important parameter in understanding Venus geological evolution, therefore, is its present surface heat flow. Before the complications of survival in the hostile Venus surface environment were tackled, a prototype fluxplate heat-flow sensor was built and tested for use under synthetic stable terrestrial surface conditions. The design parameters for this prototype were that it should operate on a conforming (sand) surface, with a small, self-contained power and recording system, capable of operating without servicing for at least several days. The precision and accuracy of the system should be < 5 mW/sq m. Additional information is included in the original extended abstract.

Data Reduction and Analysis of Pioneer Venus Orbital Ion Mass Spectrometer

NASA Technical Reports Server (NTRS)

Cloutier, Paul A.

1996-01-01

Research was carried out on developing a flow field interaction model for both the dayside and nightside ionosphere of Venus. Specific topics related to the dayside ionosphere included: (1) wave particle mechanisms at the ionopause, (2) structure and dynamics of the Venus ionopause and Ionosphere, and (3) flows and fields in the Venus Ionosphere. The structure and dynamics of ion troughs was also studied in the nightside ionosphere of Venus.

3D modeling of lightning-induced electromagnetic pulses on Venus, Jupiter and Saturn

NASA Astrophysics Data System (ADS)

Pérez-Invernón, Francisco J.; Luque, Alejandro; Gordillo-Vázquez, Francisco J.

2017-04-01

Atmospheric electricity is a common phenomenon in some planets of The Solar System. We know that atmospheric discharges exist on Earth and gaseous planets; however, some characteristics of lightning on Saturn and Jupiter as well as their relevance on the effects of lightning in the atmospheres of these planets are still unknown. In the case of Venus, there exist some radio evidences of lightning, but the lack of optical observations suggests exploring indirect methods of detection, such as searching for lightning-induced transient optical emissions from the upper atmosphere. The Akatsuki probe, currently orbiting Venus, is equipped with a camera whose temporal resolution is high enough to detect optical emissions from lightning discharges and to measure nightglow enhancements. In this work, we extend previous models [1,2] to investigate the chemical impact and transient optical emissions produced by possible lightning-emitted electromagnetic pulses (EMP) in Venus, Saturn and Jupiter. Using a 3D FDTD ("Finite Differences Time Domain") model we solve the Maxwell equations coupled with the Langevin equation for electrons [3] and with a kinetic scheme, different for each planetary atmosphere. This method is useful to investigate the temporal and spatial impact of lightning-induced electromagnetic fields in the atmosphere of each planet for different lightning characteristics (e.g. energy released, orientation). This 3D FDTD model allows us to include the saturnian and jovian background magnetic field inclination and magnitude at different latitudes, and to determine the effects of different lightning channel inclinations. Results provide useful information to interpret lightning observations on giant gaseous planets and in the search for indirect optical signals from atmospheric discharge on Venus such as fast nightglow transient enhancements related to lightning as seen on Earth. Furthermore, we underline the observation of electrical discharges characteristics as a powerful tool to obtain information about planetary atmospheres, such as density profiles of electrons or other components. Our model may also be useful to extend some studies about the chemical impact of EMP pulses in the terrestrial atmosphere [4]. References [1] Luque, A., D. Dubrovin, F. J. Gordillo-Vázquez, U. Ebert, F. C. Parra-Rojas, Y. Yair, and C. Price (2014), Coupling between atmospheric layers in gaseous giant planets due to lightning-generated electromagnetic pulses, J. Geophys. Res. (Space Phys), 119, 8705, doi: 10.1002/2014JA020457. [2] Pérez-Invernón, F. J., A. Luque, and F. J. Gordillo-Vázquez (2016), Mesospheric optical signatures of possible lightning on Venus, J. Geophys. Res. (Space Phys), 121, 7026, doi: 10.1029/2016JA022886. [3] Lee, J. H., and D. K. Kalluri (1999), Three-dimensional FDTD simulation of electromagnetic wave transformation in a dynamic inhomogeneous magnetized plasma, IEEE Transactions on Antennas and Propagation, 47, 1146, doi:10.1109/8.785745. [4] Marshall, R. A., U. S. Inan, and V. S. Glukhov (2010), Elves and associated electron density changes due to cloud-to-ground and in-cloud lightning discharges, J. Geophys. Res. (Space Phys), 115, A00E17, doi:10.1029/2009JA014469.

A multipurpose camera system for monitoring Kīlauea Volcano, Hawai'i

USGS Publications Warehouse

Patrick, Matthew R.; Orr, Tim R.; Lee, Lopaka; Moniz, Cyril J.

2015-01-01

We describe a low-cost, compact multipurpose camera system designed for field deployment at active volcanoes that can be used either as a webcam (transmitting images back to an observatory in real-time) or as a time-lapse camera system (storing images onto the camera system for periodic retrieval during field visits). The system also has the capability to acquire high-definition video. The camera system uses a Raspberry Pi single-board computer and a 5-megapixel low-light (near-infrared sensitive) camera, as well as a small Global Positioning System (GPS) module to ensure accurate time-stamping of images. Custom Python scripts control the webcam and GPS unit and handle data management. The inexpensive nature of the system allows it to be installed at hazardous sites where it might be lost. Another major advantage of this camera system is that it provides accurate internal timing (independent of network connection) and, because a full Linux operating system and the Python programming language are available on the camera system itself, it has the versatility to be configured for the specific needs of the user. We describe example deployments of the camera at Kīlauea Volcano, Hawai‘i, to monitor ongoing summit lava lake activity. 

The orbital evolution of the Aten asteroids over 11,550 years (9300 BC to 2250 AD)

NASA Astrophysics Data System (ADS)

Zausaev, A. F.; Pushkarev, A. N.

1991-04-01

The orbital evolution of five Aten asteroids was monitored by the Everhart method in the time interval from 9300 BC to 2250 AD. The closest encounters with large planets in the evolution process are calculated. Four out of five asteroids exhibit stable resonances with earth and Venus over the period from 9300 BC to 2250 AD.

Planetary Research Center. [astronomical photography of planetary surfaces and atmospheres

NASA Technical Reports Server (NTRS)

Baum, W. A.; Millis, R. L.; Bowell, E. L. G.

1974-01-01

Extensive Earth-based photography of Mars, Jupiter, and Venus is presented which monitors the atmospheric and/or surface changes that take place day to day. Color pictures are included of the 1973 dust storm on Mars, showing the daily cycle of the storm's regeneration. Martian topography, and the progress of the storm is examined. Areas most affected by the storm are summarized.

Anaesthetics stop diverse plant organ movements, affect endocytic vesicle recycling and ROS homeostasis, and block action potentials in Venus flytraps.

PubMed

Yokawa, K; Kagenishi, T; Pavlovic, A; Gall, S; Weiland, M; Mancuso, S; Baluška, F

2017-12-11

Anaesthesia for medical purposes was introduced in the 19th century. However, the physiological mode of anaesthetic drug actions on the nervous system remains unclear. One of the remaining questions is how these different compounds, with no structural similarities and even chemically inert elements such as the noble gas xenon, act as anaesthetic agents inducing loss of consciousness. The main goal here was to determine if anaesthetics affect the same or similar processes in plants as in animals and humans. A single-lens reflex camera was used to follow organ movements in plants before, during and after recovery from exposure to diverse anaesthetics. Confocal microscopy was used to analyse endocytic vesicle trafficking. Electrical signals were recorded using a surface AgCl electrode. Mimosa leaves, pea tendrils, Venus flytraps and sundew traps all lost both their autonomous and touch-induced movements after exposure to anaesthetics. In Venus flytrap, this was shown to be due to the loss of action potentials under diethyl ether anaesthesia. The same concentration of diethyl ether immobilized pea tendrils. Anaesthetics also impeded seed germination and chlorophyll accumulation in cress seedlings. Endocytic vesicle recycling and reactive oxygen species (ROS) balance, as observed in intact Arabidopsis root apex cells, were also affected by all anaesthetics tested. Plants are sensitive to several anaesthetics that have no structural similarities. As in animals and humans, anaesthetics used at appropriate concentrations block action potentials and immobilize organs via effects on action potentials, endocytic vesicle recycling and ROS homeostasis. Plants emerge as ideal model objects to study general questions related to anaesthesia, as well as to serve as a suitable test system for human anaesthesia. © The Authors 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Equatorial jet in the lower to middle cloud layer of Venus revealed by Akatsuki

PubMed Central

Horinouchi, Takeshi; Murakami, Shin-ya; Satoh, Takehiko; Peralta, Javier; Ogohara, Kazunori; Kouyama, Toru; Imamura, Takeshi; Kashimura, Hiroki; Limaye, Sanjay S.; McGouldrick, Kevin; Nakamura, Masato; Sato, Takao M.; Sugiyama, Ko-ichiro; Takagi, Masahiro; Watanabe, Shigeto; Yamada, Manabu; Yamazaki, Atsushi; Young, Eliot F.

2018-01-01

The Venusian atmosphere is in a state of superrotation where prevailing westward winds move much faster than the planet’s rotation. Venus is covered with thick clouds that extend from about 45 to 70 km altitude, but thermal radiation emitted from the lower atmosphere and the surface on the planet’s night-side escapes to space at narrow spectral windows of near-infrared. The radiation can be used to estimate winds by tracking the silhouettes of clouds in the lower and middle cloud regions below about 57 km in altitude. Estimates of wind speeds have ranged from 50 to 70 m/s at low- to mid-latitudes, either nearly constant across latitudes or with winds peaking at mid-latitudes. Here we report the detection of winds at low latitude exceeding 80 m/s using IR2 camera images from the Akatsuki orbiter taken during July and August 2016. The angular speed around the planetary rotation axis peaks near the equator, which we suggest is consistent with an equatorial jet, a feature that has not been observed previously in the Venusian atmosphere. The mechanism producing the jet remains unclear. Our observations reveal variability in the zonal flow in the lower and middle cloud region that may provide new challenges and clues to the dynamics of Venus’s atmospheric superrotation. PMID:29887914

Using hacked point and shoot cameras for time-lapse snow cover monitoring in an Alpine valley

NASA Astrophysics Data System (ADS)

Weijs, S. V.; Diebold, M.; Mutzner, R.; Golay, J. R.; Parlange, M. B.

2012-04-01

In Alpine environments, monitoring snow cover is essential get insight in the hydrological processes and water balance. Although measurement techniques based on LIDAR are available, their cost is often a restricting factor. In this research, an experiment was done using a distributed array of cheap consumer cameras to get insight in the spatio-temporal evolution of snowpack. Two experiments are planned. The first involves the measurement of eolic snow transport around a hill, to validate a snow saltation model. The second monitors the snowmelt during the melting season, which can then be combined with data from a wireless network of meteorological stations and discharge measurements at the outlet of the catchment. The poster describes the hardware and software setup, based on an external timer circuit and CHDK, the Canon Hack Development Kit. This latter is a flexible and developing software package, released under a GPL license. It was developed by hackers that reverse engineered the firmware of the camera and added extra functionality such as raw image output, more full control of the camera, external trigger and motion detection, and scripting. These features make it a great tool for geosciences. Possible other applications involve aerial stereo photography, monitoring vegetation response. We are interested in sharing experiences and brainstorming about new applications. Bring your camera!

Video monitoring in the Gadria debris flow catchment: preliminary results of large scale particle image velocimetry (LSPIV)

NASA Astrophysics Data System (ADS)

Theule, Joshua; Crema, Stefano; Comiti, Francesco; Cavalli, Marco; Marchi, Lorenzo

2015-04-01

Large scale particle image velocimetry (LSPIV) is a technique mostly used in rivers to measure two dimensional velocities from high resolution images at high frame rates. This technique still needs to be thoroughly explored in the field of debris flow studies. The Gadria debris flow monitoring catchment in Val Venosta (Italian Alps) has been equipped with four MOBOTIX M12 video cameras. Two cameras are located in a sediment trap located close to the alluvial fan apex, one looking upstream and the other looking down and more perpendicular to the flow. The third camera is in the next reach upstream from the sediment trap at a closer proximity to the flow. These three cameras are connected to a field shelter equipped with power supply and a server collecting all the monitoring data. The fourth camera is located in an active gully, the camera is activated by a rain gauge when there is one minute of rainfall. Before LSPIV can be used, the highly distorted images need to be corrected and accurate reference points need to be made. We decided to use IMGRAFT (an opensource image georectification toolbox) which can correct distorted images using reference points and camera location, and then finally rectifies the batch of images onto a DEM grid (or the DEM grid onto the image coordinates). With the orthorectified images, we used the freeware Fudaa-LSPIV (developed by EDF, IRSTEA, and DeltaCAD Company) to generate the LSPIV calculations of the flow events. Calculated velocities can easily be checked manually because of the already orthorectified images. During the monitoring program (since 2011) we recorded three debris flow events at the sediment trap area (each with very different surge dynamics). The camera in the gully was in operation in 2014 which managed to record granular flows and rockfalls, which particle tracking may be more appropriate for velocity measurements. The four cameras allows us to explore the limitations of camera distance, angle, frame rate, and image quality.

Can Commercial Digital Cameras Be Used as Multispectral Sensors? A Crop Monitoring Test.

PubMed

Lebourgeois, Valentine; Bégué, Agnès; Labbé, Sylvain; Mallavan, Benjamin; Prévot, Laurent; Roux, Bruno

2008-11-17

The use of consumer digital cameras or webcams to characterize and monitor different features has become prevalent in various domains, especially in environmental applications. Despite some promising results, such digital camera systems generally suffer from signal aberrations due to the on-board image processing systems and thus offer limited quantitative data acquisition capability. The objective of this study was to test a series of radiometric corrections having the potential to reduce radiometric distortions linked to camera optics and environmental conditions, and to quantify the effects of these corrections on our ability to monitor crop variables. In 2007, we conducted a five-month experiment on sugarcane trial plots using original RGB and modified RGB (Red-Edge and NIR) cameras fitted onto a light aircraft. The camera settings were kept unchanged throughout the acquisition period and the images were recorded in JPEG and RAW formats. These images were corrected to eliminate the vignetting effect, and normalized between acquisition dates. Our results suggest that 1) the use of unprocessed image data did not improve the results of image analyses; 2) vignetting had a significant effect, especially for the modified camera, and 3) normalized vegetation indices calculated with vignetting-corrected images were sufficient to correct for scene illumination conditions. These results are discussed in the light of the experimental protocol and recommendations are made for the use of these versatile systems for quantitative remote sensing of terrestrial surfaces.

The dynamics of the Venus ionosphere

NASA Technical Reports Server (NTRS)

Miller, K. L.

1988-01-01

Data from the Pioneer-Venus orbiter has demonstrated the importance of understanding ion dynamics in the Venus ionosphere. The analysis of the data has shown that during solar maximum the topside Venus ionosphere in the dark hemisphere is generated almost entirely on the dayside of the planet during solar maximum, and flows with supersonic velocities across the terminator into the nightside. The flow field in the ionosphere is mainly axially-symmetric about the sun-Venus axis, as are most measured ionospheric quantities. The primary data base used consisted of the ion velocity measurements made by the RPA during three years that periapsis of the orbiter was maintained in the Venus ionosphere. Examples of ion velocities were published and modeled. This research examined the planetary flow patterns measured in the Venus ionosphere, and the physical implications of departures from the mean flow.

ESA Venus Entry Probe Study

NASA Technical Reports Server (NTRS)

vandenBerg, M. L.; Falkner, P.; Phipps, A.; Underwood, J. C.; Lingard, J. S.; Moorhouse, J.; Kraft, S.; Peacock, A.

2005-01-01

The Venus Entry Probe is one of ESA s Technology Reference Studies (TRS). The purpose of the Technology Reference Studies is to provide a focus for the development of strategically important technologies that are of likely relevance for future scientific missions. The aim of the Venus Entry Probe TRS is to study approaches for low cost in-situ exploration of Venus and other planetary bodies with a significant atmosphere. In this paper, the mission objectives and an outline of the mission concept of the Venus Entry Probe TRS are presented.

Colonization of Venus

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A.

2003-01-01

Although the surface of Venus is an extremely hostile environment, at about 50 kilometers above the surface the atmosphere of Venus is the most earthlike environment (other than Earth itself) in the solar system. It is proposed here that in the near term, human exploration of Venus could take place from aerostat vehicles in the atmosphere, and that in the long term, permanent settlements could be made in the form of cities designed to float at about fifty kilometer altitude in the atmosphere of Venus.

Description, accessibility and usage of SOIR/Venus Express atmospheric profiles of Venus distributed in VESPA (Virtual European Solar and Planetary Access)

NASA Astrophysics Data System (ADS)

Trompet, L.; Geunes, Y.; Ooms, T.; Mahieux, A.; Wilquet, V.; Chamberlain, S.; Robert, S.; Thomas, I. R.; Erard, S.; Cecconi, B.; Le Sidaner, P.; Vandaele, A. C.

2018-01-01

Venus Express SOIR profiles of pressure, temperature and number densities of different constituents of the mesosphere and lower thermosphere of Venus are the only experimental data covering the 60 km to 220 km range of altitudes at the terminator of Venus. This unique dataset is now available in the open access VESPA infrastructure. This paper describes the content of these data products and provides some use cases.

Thermal structure and minor species distribution of Venus mesosphere by ALMA submm observations

NASA Astrophysics Data System (ADS)

Piccialli, Arianna; Moreno, Raphael; Encrenaz, Therese; Fouchet, Thierry; Lellouch, Emmanuel; Moullet, Arielle; Widemann, Thomas

2015-11-01

Venus upper atmosphere (70-150 km altitude) is a transition region characterized by a complex dynamics: strong retrograde zonal winds dominate the lower mesosphere while a solar-to-antisolar circulation is observed in the upper mesosphere/lower thermosphere. In addition, photochemical processes play an important role at these altitudes and affect the thermal structure and chemical stability of the entire atmosphere. Sulfur dioxide and water vapor are key species in the photochemical cycles taking place in the troposphere and mesosphere of Venus. They are carried by convective transport, together with the Hadley circulation, up to about 60 km where SO2 is photodissociated and oxydated, leading to the formation of H2SO4 which condenses in the clouds enshrouding the planet. Previous observations obtained by several instruments on board Venus Express and during ground-based campaigns have shown evidence of strong temporal variations, both on day-to-day as well as longer timescales, of density, temperature and SO2 abundance. Such strong variability is still not well understood.Submillimeter observations obtained with the Atacama Large Millimeter Array (ALMA) offer the possibility of probing Venus upper mesosphere and of monitoring minor species, winds and the thermal structure. A first set of observations was obtained on November 14, 15, 26 and 27, 2011 during the first ALMA Early Science observation cycle. These observations targeted SO2, SO, HDO and CO transitions around 345 GHz during four sequences of 30 minutes each. The Venus’ disk was about 11” with an illumination factor of 90%, so that mostly the dayside of the planet was mapped.Assuming nominal night-time and dayside CO abundance profiles from Clancy et al. 2013, we retrieved vertical temperature profiles over the entire disk as a function of latitude and local time for the four days of observation. Temperature profiles were later used to derive the abundances of minor species (HDO, SO, SO2) in each pixel of the disk in order to study their spatial and temporal variability.

Venus Aerobot Multisonde Mission

NASA Technical Reports Server (NTRS)

Cutts, James A.; Kerzhanovich, Viktor; Balaram, J. Bob; Campbell, Bruce; Gershaman, Robert; Greeley, Ronald; Hall, Jeffery L.; Cameron, Jonathan; Klaasen, Kenneth; Hansen, David M.

1999-01-01

Robotic exploration of Venus presents many challenges because of the thick atmosphere and the high surface temperatures. The Venus Aerobot Multisonde mission concept addresses these challenges by using a robotic balloon or aerobot to deploy a number of short lifetime probes or sondes to acquire images of the surface. A Venus aerobot is not only a good platform for precision deployment of sondes but is very effective at recovering high rate data. This paper describes the Venus Aerobot Multisonde concept and discusses a proposal to NASA's Discovery program using the concept for a Venus Exploration of Volcanoes and Atmosphere (VEVA). The status of the balloon deployment and inflation, balloon envelope, communications, thermal control and sonde deployment technologies are also reviewed.

Implications of convection in the moon and the terrestrial planets

NASA Technical Reports Server (NTRS)

Turcotte, Donald L.

1991-01-01

A comprehensive review is made of the thermal chemical evolution of the moon and the terrestrial planets. New results are presented which were obtained for Venus by the Magellan Mission the efforts were concentrated on this planet. Alternative models were examined for the thermal structure of the lithosphere of Venus. The statistical distribution was studied of the locations of the coronae on Venus. Models were examined for the patterns of faulting around the coronae on Venus. A series was considered of viscous models for the development and relaxation of elevation anomalies on Venus. And rates were studied of solidification of volcanic flows on Venus. Both radiative and convective heat transfer were considered.

An integrated multispectral video and environmental monitoring system for the study of coastal processes and the support of beach management operations

NASA Astrophysics Data System (ADS)

Ghionis, George; Trygonis, Vassilis; Karydis, Antonis; Vousdoukas, Michalis; Alexandrakis, George; Drakopoulos, Panos; Amdreadis, Olympos; Psarros, Fotis; Velegrakis, Antonis; Poulos, Serafim

2016-04-01

Effective beach management requires environmental assessments that are based on sound science, are cost-effective and are available to beach users and managers in an accessible, timely and transparent manner. The most common problems are: 1) The available field data are scarce and of sub-optimal spatio-temporal resolution and coverage, 2) our understanding of local beach processes needs to be improved in order to accurately model/forecast beach dynamics under a changing climate, and 3) the information provided by coastal scientists/engineers in the form of data, models and scientific interpretation is often too complicated to be of direct use by coastal managers/decision makers. A multispectral video system has been developed, consisting of one or more video cameras operating in the visible part of the spectrum, a passive near-infrared (NIR) camera, an active NIR camera system, a thermal infrared camera and a spherical video camera, coupled with innovative image processing algorithms and a telemetric system for the monitoring of coastal environmental parameters. The complete system has the capability to record, process and communicate (in quasi-real time) high frequency information on shoreline position, wave breaking zones, wave run-up, erosion hot spots along the shoreline, nearshore wave height, turbidity, underwater visibility, wind speed and direction, air and sea temperature, solar radiation, UV radiation, relative humidity, barometric pressure and rainfall. An innovative, remotely-controlled interactive visual monitoring system, based on the spherical video camera (with 360°field of view), combines the video streams from all cameras and can be used by beach managers to monitor (in real time) beach user numbers, flow activities and safety at beaches of high touristic value. The high resolution near infrared cameras permit 24-hour monitoring of beach processes, while the thermal camera provides information on beach sediment temperature and moisture, can detect upwelling in the nearshore zone, and enhances the safety of beach users. All data can be presented in real- or quasi-real time and are stored for future analysis and training/validation of coastal processes models. Acknowledgements: This work was supported by the project BEACHTOUR (11SYN-8-1466) of the Operational Program "Cooperation 2011, Competitiveness and Entrepreneurship", co-funded by the European Regional Development Fund and the Greek Ministry of Education and Religious Affairs.

Instrumentation for Infrared Airglow Clutter.

DTIC Science & Technology

1987-03-10

gain, and filter position to the Camera Head, and monitors these parameters as well as preamp video. GAZER is equipped with a Lenzar wide angle, low...Specifications/Parameters VIDEO SENSOR: Camera ...... . LENZAR Intensicon-8 LLLTV using 2nd gen * micro-channel intensifier and proprietary camera tube

Mariner V: Plasma and Magnetic Fields Observed near Venus.

PubMed

Bridge, H S; Lazarus, A J; Snyder, C W; Smith, E J; Davis, L; Coleman, P J; Jones, D E

1967-12-29

Abrupt changes in the amplitude of the magnetic fluctuations, in the field strength, and in the plasma properties, were observed with Mariner V near Venus. They provide clear evidence for the presence of a bow shock around the planet, similar to, but much smaller than, that observed at Earth. The observations appear consistent with an interaction of the solar wind with the ionosphere of Venus. No planetary field could be detected, but a steady radial field and very low plasma density were found 10,000 to 20,000 kilometers behind Venus and 8,000 to 12,000 kilometers from the Sun-Venus line. These observations may be interpreted as relating to an expansion wave tending to fill the cavity produced by Venus in the solar wind. The upper limit to the magnetic dipole moment of Venus is estimated to be within a factor of 2 of 10(-3) items that of Earth.

Comparison of dayside current layers in Venus' ionosphere and earth's equatorial electrojet

NASA Technical Reports Server (NTRS)

Cole, Keith D.

1993-01-01

The major physical aspects of the equatorial electrojet of Earth and the dayside ionospheric current layers of Venus are compared, viz., the electric current intensity and total current, roles of electric field, pressure and gravity, diffusion time scales, and the Bernouille effect. The largest potential differences, of the order of 10 volts, horizontally across the dayside ionosphere of Venus, have important implications for possible dynamo action in the Venus ionosphere and the application of an electric field from the lower atmosphere or from the solar wind. An upper limit to the horizontal scale of vertical magnetic fields in the Venus ionosphere is estimated thereby for the first time. New upper limits on the velocity in, and thickness of, a possible S layer at Venus are presented. If an S layer exists, it is only for extreme conditions of the solar wind. A mechanism for formation of magnetic ropes in the Venus ionosphere is also proposed.

Origin and evolution of the atmosphere of Venus

NASA Technical Reports Server (NTRS)

Donahue, T. M.; Pollack, J. B.

1983-01-01

Implications for the origin and evolution of the terrestrial planets are drawn from a comparison of the Venus, earth and Mars atmosphere volatile inventories. Attention is given to the possible loss of an appreciable amount of water from Venus, in light of recent evidence for a 100-fold deuterium enrichment. Ar-40 and He-4 abundances suggest that outgassing has been inefficient for much of Venus's lifetime, in keeping with evidence for a lower level of tectonic activity on Venus than on the earth. Attention is also given to Venus's CO2 geochemistry. The picture now emerging is that of a Venus that began to evolve along a path similar to that of the earth, but suffered a catastrophic, runaway greenhouse effect early in its lifetime. How early the castastrophe occurred may be suggested by the presently low inventories of radiogenic argon and helium in its atmosphere.

Using Arago's spot to monitor optical axis shift in a Petzval refractor.

PubMed

Bruns, Donald G

2017-03-10

Measuring the change in the optical alignment of a camera attached to a telescope is necessary to perform astrometric measurements. Camera movement when the telescope is refocused changes the plate constants, invalidating the calibration. Monitoring the shift in the optical axis requires a stable internal reference source. This is easily implemented in a Petzval refractor by adding an illuminated pinhole and a small obscuration that creates a spot of Arago on the camera. Measurements of the optical axis shift for a commercial telescope are given as an example.

Man with a Mission: Jean-Dominique Cassini

NASA Astrophysics Data System (ADS)

Belkora, Leila

2004-03-01

Jean-Dominique Cassini, for whom the Cassini mission to Saturn is named, is best known for his early understanding of that planet's rings. This article is an overview of his influential career in astronomy and other scientific fields.= Born in Italy in1625 and formally educated at an early age, he was a professor of astronomy at the University of Bologna, a leading center of learning in Europe of the time. He was an early observer of Jupiter, Mars, and Venus. He is best known for constructing a giant pinhole camera in a cathedral that he used with a meridian line on the floor to track the Sun's image through the year, thus providing the Catholic Church with a reliable calendar. Cassini also used the pinhole camera observations to calculate the variation in the distance between the Sun and Earth, thus lending support to the Copernican (Sun-centered) view of the solar system. Cassini moved to Paris at the request of King Louis XIV, originally to oversee the surveying needed for a new map system of France, but ultimately he took over as the director of the Paris Observatory. Cassini's descendants ran the observatory there for the following century.

Optimising Camera Traps for Monitoring Small Mammals

PubMed Central

Glen, Alistair S.; Cockburn, Stuart; Nichols, Margaret; Ekanayake, Jagath; Warburton, Bruce

2013-01-01

Practical techniques are required to monitor invasive animals, which are often cryptic and occur at low density. Camera traps have potential for this purpose, but may have problems detecting and identifying small species. A further challenge is how to standardise the size of each camera’s field of view so capture rates are comparable between different places and times. We investigated the optimal specifications for a low-cost camera trap for small mammals. The factors tested were 1) trigger speed, 2) passive infrared vs. microwave sensor, 3) white vs. infrared flash, and 4) still photographs vs. video. We also tested a new approach to standardise each camera’s field of view. We compared the success rates of four camera trap designs in detecting and taking recognisable photographs of captive stoats ( Mustela erminea ), feral cats (Felis catus) and hedgehogs ( Erinaceus europaeus ). Trigger speeds of 0.2–2.1 s captured photographs of all three target species unless the animal was running at high speed. The camera with a microwave sensor was prone to false triggers, and often failed to trigger when an animal moved in front of it. A white flash produced photographs that were more readily identified to species than those obtained under infrared light. However, a white flash may be more likely to frighten target animals, potentially affecting detection probabilities. Video footage achieved similar success rates to still cameras but required more processing time and computer memory. Placing two camera traps side by side achieved a higher success rate than using a single camera. Camera traps show considerable promise for monitoring invasive mammal control operations. Further research should address how best to standardise the size of each camera’s field of view, maximise the probability that an animal encountering a camera trap will be detected, and eliminate visible or audible cues emitted by camera traps. PMID:23840790

The rising star of high-oleic Virginia peanuts: A summary of data supporting the release of 'VENUS'

USDA-ARS?s Scientific Manuscript database

'VENUS' is a large-seeded high-oleic Virginia-type peanut that has enhanced Sclerotinia blight and pod rot tolerance when compared to the cultivar Jupiter. 'VENUS' is the first high-oleic Virginia peanut developed for and proposed for release in the Southwestern US. 'VENUS' (experimental designati...

Volatile transport on Venus and implications for surface geochemistry and geology

NASA Technical Reports Server (NTRS)

Brackett, Robert A.; Fegley, Bruce; Arvidson, Raymond E.

1995-01-01

The high vapor pressure of volatile metal halides and chalcogenides (e.g., of Cu, Zn, Sn, Pb, As, Sb, Bi) at typical Venus surface temperatures, coupled with the altitude-dependent temperature gradient of approximately 8.5 K/km, is calculated to transport volatile metal vapors to the highlands of Venus, where condensation and accumulation will occur. The predicted geochemistry of volatile metals on Venus is supported by observations of CuCl in volcanic gases at Kilauea and Nyiragongo, and large enrichments of these and other volatile elements in terrestrial volcanic aerosols. A one-dimensional finite difference vapor transport model shows the diffusive migration of a thickness of 0.01 to greater than 10 microns/yr of moderately to highly volatile phases (e.g., metal halides and chalcogenides) from the hot lowlands (740 K) to the cold highlands (660 K) on Venus. The diffusive transport of volatile phases on Venus may explain the observed low emissivity of the Venusian highlands, hazes at 6-km altitude observed by two Pioneer Venus entry probes, and the Pioneer Venus entry probe anomalies at 12.5 km.

Venus Gravity Handbook

NASA Technical Reports Server (NTRS)

Konopliv, Alexander S.; Sjogren, William L.

1996-01-01

This report documents the Venus gravity methods and results to date (model MGNP90LSAAP). It is called a handbook in that it contains many useful plots (such as geometry and orbit behavior) that are useful in evaluating the tracking data. We discuss the models that are used in processing the Doppler data and the estimation method for determining the gravity field. With Pioneer Venus Orbiter and Magellan tracking data, the Venus gravity field was determined complete to degree and order 90 with the use of the JPL Cray T3D Supercomputer. The gravity field shows unprecedented high correlation with topography and resolution of features to the 2OOkm resolution. In the procedure for solving the gravity field, other information is gained as well, and, for example, we discuss results for the Venus ephemeris, Love number, pole orientation of Venus, and atmospheric densities. Of significance is the Love number solution which indicates a liquid core for Venus. The ephemeris of Venus is determined to an accuracy of 0.02 mm/s (tens of meters in position), and the rotation period to 243.0194 +/- 0.0002 days.

Purification and characterization of hemagglutinating proteins from Poker-chip Venus (Meretrix lusoria) and Corbicula clam (Corbicula fluminea).

PubMed

Cheng, Chin-Fu; Hung, Shao-Wen; Chang, Yung-Chung; Chen, Ming-Hui; Chang, Chen-Hsuan; Tsou, Li-Tse; Tu, Ching-Yu; Lin, Yu-Hsing; Liu, Pan-Chen; Lin, Shiun-Long; Wang, Way-Shyan

2012-01-01

Hemagglutinating proteins (HAPs) were purified from Poker-chip Venus (Meretrix lusoria) and Corbicula clam (Corbicula fluminea) using gel-filtration chromatography on a Sephacryl S-300 column. The molecular weights of the HAPs obtained from Poker-chip Venus and Corbicula clam were 358 kDa and 380 kDa, respectively. Purified HAP from Poker-chip Venus yielded two subunits with molecular weights of 26 kDa and 29 kDa. However, only one HAP subunit was purified from Corbicula clam, and its molecular weight was 32 kDa. The two Poker-chip Venus HAPs possessed hemagglutinating ability (HAA) for erythrocytes of some vertebrate animal species, especially tilapia. Moreover, HAA of the HAP purified from Poker-chip Venus was higher than that of the HAP of Corbicula clam. Furthermore, Poker-chip Venus HAPs possessed better HAA at a pH higher than 7.0. When the temperature was at 4°C-10°C or the salinity was less than 0.5‰, the two Poker-chip Venus HAPs possessed better HAA compared with that of Corbicula clam.

Quantitative tests for plate tectonics on Venus

NASA Technical Reports Server (NTRS)

Kaula, W. M.; Phillips, R. J.

1981-01-01

Quantitative comparisons are made between the characteristics of plate tectonics on the earth and those which are possible on Venus. Considerations of the factors influencing rise height and relating the decrease in rise height to plate velocity indicate that the rate of topographic dropoff from spreading centers should be about half that on earth due to greater rock-fluid density contrast and lower temperature differential between the surface and interior. Statistical analyses of Pioneer Venus radar altimetry data and global earth elevation data is used to identify 21,000 km of ridge on Venus and 33,000 km on earth, and reveal Venus ridges to have a less well-defined mode in crest heights and a greater concavity than earth ridges. Comparison of the Venus results with the spreading rates and associated heat flow on earth reveals plate creation rates on Venus to be 0.7 sq km/year or less and indicates that not more than 15% of Venus's energy is delivered to the surface by plate tectonics, in contrast to values of 2.9 sq km a year and 70% for earth.

Pioneer Venus Data Analysis

NASA Technical Reports Server (NTRS)

Jones, Douglas E.

1996-01-01

Analysis and interpretation of data from the Orbiter Retarding Potential Analyzer (ORPA) onboard the Pioneer Venus Orbiter is reported. By comparing ORPA data to proton data from the Orbiter Plasma Analyzer (OPA), it was found that the ORPA suprathermal electron densities taken outside the Venusian ionopause represent solar wind electron densities, thus allowing the high resolution study of Venus bow shocks using both magnetic field and solar wind electron data. A preliminary analysis of 366 bow shock penetrations was completed using the solar wind electron data as determined from ORPA suprathermal electron densities and temperatures, resulting in an estimate of the extent to which mass loading pickup of O+ (UV ionized O atoms flowing out of the Venus atmosphere) upstream of the Venus obstacle occurred. The pickup of O+ averaged 9.95%, ranging from 0.78% to 23.63%. Detailed results are reported in two attached theses: (1) Comparison of ORPA Suprathermal Electron and OPA Solar Wind Proton Data from the Pioneer Venus Orbiter and (2) Pioneer Venus Orbiter Retarding Potential Analyzer Observations of the Electron Component of the Solar Wind, and of the Venus Bow Shock and Magnetosheath.

Geological Mapping of Fortuna Tessera (V-2): Venus and Earth's Archean Process Comparisons

NASA Technical Reports Server (NTRS)

Head, James W.; Hurwitz,D. M.; Ivanov, M. A.; Basilevsky, A. T.; Kumar, P. Senthil

2008-01-01

The geological features, structures, thermal conditions, interpreted processes, and outstanding questions related to both the Earth's Archean and Venus share many similarities and we are using a problem-oriented approach to Venus mapping, guided by insight from the Archean record of the Earth, to gain new insight into the evolution of Venus and Earth's Archean. The Earth's preserved and well-documented Archean record provides important insight into high heat-flux tectonic and magmatic environments and structures and the surface of Venus reveals the current configuration and recent geological record of analogous high-temperature environments unmodified by subsequent several billion years of segmentation and overprinting, as on Earth. Elsewhere we have addressed the nature of the Earth's Archean, the similarities to and differences from Venus, and the specific Venus and Earth-Archean problems on which progress might be made through comparison. Here we present the major goals of the Venus-Archean comparison and show how preliminary mapping of the geology of the V-2 Fortuna Tessera quadrangle is providing insight on these problems. We have identified five key themes and questions common to both the Archean and Venus, the assessment of which could provide important new insights into the history and processes of both planets.

Venus' Spectral Signatures and the Potential for Life in the Clouds.

PubMed

Limaye, Sanjay S; Mogul, Rakesh; Smith, David J; Ansari, Arif H; Słowik, Grzegorz P; Vaishampayan, Parag

2018-03-30

The lower cloud layer of Venus (47.5-50.5 km) is an exceptional target for exploration due to the favorable conditions for microbial life, including moderate temperatures and pressures (∼60°C and 1 atm), and the presence of micron-sized sulfuric acid aerosols. Nearly a century after the ultraviolet (UV) contrasts of Venus' cloud layer were discovered with Earth-based photographs, the substances and mechanisms responsible for the changes in Venus' contrasts and albedo are still unknown. While current models include sulfur dioxide and iron chloride as the UV absorbers, the temporal and spatial changes in contrasts, and albedo, between 330 and 500 nm, remain to be fully explained. Within this context, we present a discussion regarding the potential for microorganisms to survive in Venus' lower clouds and contribute to the observed bulk spectra. In this article, we provide an overview of relevant Venus observations, compare the spectral and physical properties of Venus' clouds to terrestrial biological materials, review the potential for an iron- and sulfur-centered metabolism in the clouds, discuss conceivable mechanisms of transport from the surface toward a more habitable zone in the clouds, and identify spectral and biological experiments that could measure the habitability of Venus' clouds and terrestrial analogues. Together, our lines of reasoning suggest that particles in Venus' lower clouds contain sufficient mass balance to harbor microorganisms, water, and solutes, and potentially sufficient biomass to be detected by optical methods. As such, the comparisons presented in this article warrant further investigations into the prospect of biosignatures in Venus' clouds. Key Words: Venus-Clouds-Life-Habitability-Microorganism-Albedo-Spectroscopy-Biosignatures-Aerosol-Sulfuric Acid. Astrobiology 18, xxx-xxx.

Venus: Our Misunderstood Sister

NASA Astrophysics Data System (ADS)

Dyar, Darby; Smrekar, Suzanne E.

2018-01-01

Of all known bodies in the galaxy, Venus is the most Earth-like in size, composition, surface age, and incoming energy. As we search for habitable planets around other stars, learning how Venus works is critical to understanding how Earth evolved to host life, and whether rocky exoplanets in stars’ habitable zones are faraway Earths or Venuses. What caused Venus’ path to its present hostile environment, devoid of oceans, magnetic field, and plate tectonics? This talk reviews recent mission results, presents key unresolved science questions, and describes proposed missions to answer these questions.Despite its importance in understanding habitability, Venus is the least-explored rocky planet, last visited by NASA in 1994. Fundamental, unanswered questions for Venus include: 1. How did Venus evolve differently? 2. How have volatiles shaped its evolution? 3. Did Venus catastrophically resurface? 4. What geologic processes are active today? 5. Why does Venus lack plate tectonics?On Earth, plate tectonics supports long-term climate stability and habitability by cycling volatiles in and out of the mantle. New information on planetary volatiles disputes the long-held notion that Venus’ interior is dry; several lines of evidence indicate that planets start out wet, creating long-term atmospheres by outgassing. ESA’s Venus Express mission provided evidence for recent and ongoing volcanism and for Si-rich crust like Earth’s continents. New hypotheses suggest that lithospheric temperature can explain why Venus lacks tectonics, and are consistent with present-day initiation of subduction on Venus.New data are needed to answer these key questions of rocky planet evolution. Orbital IR data can be acquired through windows in Venus’ CO2-rich atmosphere, informing surface mineralogy, rock types, cloud variations, and active volcanism. High resolution gravity, radar, and topography data along with mineralogical constraints must be obtained. Mineralogy and geochemistry data acquisition on the surface is feasible with current technology, though challenging. Orbital measurements of noble gases/stable isotopes are needed to constrain volatile sources, escape processes, and the history of volcanic outgassing in Venus’ atmosphere.

Venus Surface Composition Constrained by Observation and Experiment

NASA Astrophysics Data System (ADS)

Gilmore, Martha; Treiman, Allan; Helbert, Jörn; Smrekar, Suzanne

2017-11-01

New observations from the Venus Express spacecraft as well as theoretical and experimental investigation of Venus analogue materials have advanced our understanding of the petrology of Venus melts and the mineralogy of rocks on the surface. The VIRTIS instrument aboard Venus Express provided a map of the southern hemisphere of Venus at ˜1 μm allowing, for the first time, the definition of surface units in terms of their 1 μm emissivity and derived mineralogy. Tessera terrain has lower emissivity than the presumably basaltic plains, consistent with a more silica-rich or felsic mineralogy. Thermodynamic modeling and experimental production of melts with Venera and Vega starting compositions predict derivative melts that range from mafic to felsic. Large volumes of felsic melts require water and may link the formation of tesserae to the presence of a Venus ocean. Low emissivity rocks may also be produced by atmosphere-surface weathering reactions unlike those seen presently. High 1 μm emissivity values correlate to stratigraphically recent flows and have been used with theoretical and experimental predictions of basalt weathering to identify regions of recent volcanism. The timescale of this volcanism is currently constrained by the weathering of magnetite (higher emissivity) in fresh basalts to hematite (lower emissivity) in Venus' oxidizing environment. Recent volcanism is corroborated by transient thermal anomalies identified by the VMC instrument aboard Venus Express. The interpretation of all emissivity data depends critically on understanding the composition of surface materials, kinetics of rock weathering and their measurement under Venus conditions. Extended theoretical studies, continued analysis of earlier spacecraft results, new atmospheric data, and measurements of mineral stability under Venus conditions have improved our understanding atmosphere-surface interactions. The calcite-wollastonite CO2 buffer has been discounted due, among other things, to the rarity of wollastonite and instability of carbonate at the Venus surface. Sulfur in the Venus atmosphere has been shown experimentally to react with Ca in surface minerals to produce anhydrite. The extent of this SO2 buffer is constrained by the Ca content of surface rocks and sulfur content of the atmosphere, both of which are likely variable, perhaps due to active volcanism. Experimental work on a range of semiconductor and ferroelectric minerals is placing constraints on the cause(s) of Venus' anomalously radar bright highlands.

A mobile device-based imaging spectrometer for environmental monitoring by attaching a lightweight small module to a commercial digital camera.

PubMed

Cai, Fuhong; Lu, Wen; Shi, Wuxiong; He, Sailing

2017-11-15

Spatially-explicit data are essential for remote sensing of ecological phenomena. Lately, recent innovations in mobile device platforms have led to an upsurge in on-site rapid detection. For instance, CMOS chips in smart phones and digital cameras serve as excellent sensors for scientific research. In this paper, a mobile device-based imaging spectrometer module (weighing about 99 g) is developed and equipped on a Single Lens Reflex camera. Utilizing this lightweight module, as well as commonly used photographic equipment, we demonstrate its utility through a series of on-site multispectral imaging, including ocean (or lake) water-color sensing and plant reflectance measurement. Based on the experiments we obtain 3D spectral image cubes, which can be further analyzed for environmental monitoring. Moreover, our system can be applied to many kinds of cameras, e.g., aerial camera and underwater camera. Therefore, any camera can be upgraded to an imaging spectrometer with the help of our miniaturized module. We believe it has the potential to become a versatile tool for on-site investigation into many applications.

Micro-Imagers for Spaceborne Cell-Growth Experiments

NASA Technical Reports Server (NTRS)

Behar, Alberto; Matthews, Janet; SaintAnge, Beverly; Tanabe, Helen

2006-01-01

A document discusses selected aspects of a continuing effort to develop five micro-imagers for both still and video monitoring of cell cultures to be grown aboard the International Space Station. The approach taken in this effort is to modify and augment pre-existing electronic micro-cameras. Each such camera includes an image-detector integrated-circuit chip, signal-conditioning and image-compression circuitry, and connections for receiving power from, and exchanging data with, external electronic equipment. Four white and four multicolor light-emitting diodes are to be added to each camera for illuminating the specimens to be monitored. The lens used in the original version of each camera is to be replaced with a shorter-focal-length, more-compact singlet lens to make it possible to fit the camera into the limited space allocated to it. Initially, the lenses in the five cameras are to have different focal lengths: the focal lengths are to be 1, 1.5, 2, 2.5, and 3 cm. Once one of the focal lengths is determined to be the most nearly optimum, the remaining four cameras are to be fitted with lenses of that focal length.

Continuous monitoring of Hawaiian volcanoes using thermal cameras

NASA Astrophysics Data System (ADS)

Patrick, M. R.; Orr, T. R.; Antolik, L.; Lee, R.; Kamibayashi, K.

2012-12-01

Thermal cameras are becoming more common at volcanoes around the world, and have become a powerful tool for observing volcanic activity. Fixed, continuously recording thermal cameras have been installed by the Hawaiian Volcano Observatory in the last two years at four locations on Kilauea Volcano to better monitor its two ongoing eruptions. The summit eruption, which began in March 2008, hosts an active lava lake deep within a fume-filled vent crater. A thermal camera perched on the rim of Halema`uma`u Crater, acquiring an image every five seconds, has now captured about two years of sustained lava lake activity, including frequent lava level fluctuations, small explosions , and several draining events. This thermal camera has been able to "see" through the thick fume in the crater, providing truly 24/7 monitoring that would not be possible with normal webcams. The east rift zone eruption, which began in 1983, has chiefly consisted of effusion through lava tubes onto the surface, but over the past two years has been interrupted by an intrusion, lava fountaining, crater collapse, and perched lava lake growth and draining. The three thermal cameras on the east rift zone, all on Pu`u `O`o cone and acquiring an image every several minutes, have captured many of these changes and are providing an improved means for alerting observatory staff of new activity. Plans are underway to install a thermal camera at the summit of Mauna Loa to monitor and alert to any future changes there. Thermal cameras are more difficult to install, and image acquisition and processing are more complicated than with visual webcams. Our system is based in part on the successful thermal camera installations by Italian volcanologists on Stromboli and Vulcano. Equipment includes custom enclosures with IR transmissive windows, power, and telemetry. Data acquisition is based on ActiveX controls, and data management is done using automated Matlab scripts. Higher-level data processing, also done with Matlab, includes automated measurements of lava lake level and surface crust velocity, tracking temperatures and hot areas in real-time, and alerts which notify users of notable temperature increases via text messaging. Lastly, real-time image and processed data display, which is vital for effective use of the images at the observatory, is done through a custom Web-based environment . Near real-time webcam images are displayed for the public at hvo.wr.usgs.gov/cams. Thermal cameras are costly, but have proven to be an extremely effective monitoring and research tool at the Hawaiian Volcano Observatory.

High Temperature Mechanisms for Venus Exploration

NASA Astrophysics Data System (ADS)

Ji, Jerri; Narine, Roop; Kumar, Nishant; Singh, Sase; Gorevan, Steven

Future Venus missions, including New Frontiers Venus In-Situ Explorer and three Flagship Missions - Venus Geophysical Network, Venus Mobile Explorer and Venus Surface Sample Return all focus on searching for evidence of past climate change both on the surface and in the atmospheric composition as well as in the interior dynamics of the planet. In order to achieve these goals and objectives, many key technologies need to be developed for the Venus extreme environment. These key technologies include sample acquisition systems and other high-temperature mechanisms and mobility systems capable of extended operation when directly exposed to the Venus surface or lower atmosphere environment. Honeybee Robotics has developed two types of high temperature motors, the materials and components in both motors were selected based on the requirement to survive temperatures above a minimum of 460° C, at earth atmosphere. The prototype Switched Reluctance Motor (SRM) has been operated non-continuously for over 20 hours at Venus-like conditions (460° C temperature, mostly CO2 gas environment) and it remains functional. A drilling system, actuated by two SRMs was tested in Venus-like conditions, 460° C temperature and mostly CO2 gas environment, for more than 15 hours. The drill successfully completed three tests by drilling into chalk up to 6 inches deep in each test. A first generation Brushless DC (BLDC) Motor and high temperature resolver were also tested and the feasibility of the designs was demonstrated by the extended operation of both devices under Venus-like condition. Further development of the BLDC motor and resolver continues and these devices will, ultimately, be integrated into the development of a high temperature sample acquisition scoop and high temperature joint (awarded SBIR Phase II in October, 2007). Both the SR and BLDC motors will undergo extensive testing at Venus temperature and pressure (TRL6) and are expected to be mission ready before the next New Frontiers AO release. Scalable high temperature motor, resolver and bearing developments allow for creation of long lasting sample acquisition systems, booms, robot arms and even mobility systems that operate outside of an environment-controlled landed platform on the surface of Venus. The SR and BLDC motors are no longer expected to limit the life of Venus surface operations. With the accompanying high temperature bearing and other mechanisms development, surface operations will be limited only by available power. Therefore, the motor and resolver's capability to survive for hours (and potentially longer) in the environment is a major benefit to future Venus science missions and they also allow time for communication ground loops to optimize sample target selection and the possibility for acquiring multiple samples from the surface. The extreme temperature motors, resolver and other high temperature mechanisms therefore revolutionize the exploration of Venus.

Abstracts of the Annual Meeting of Planetary Geologic Mappers, Flagstaff, AZ, 2008

NASA Technical Reports Server (NTRS)

Bleamaster, Leslie F., III (Editor); Tanaka, Kenneth L. (Editor); Kelley, Michael S. (Editor)

2008-01-01

Topics discussed include: Merging of the USGS Atlas of Mercury 1:5,000,000 Geologic Series; Geologic Mapping of the V-36 Thetis Regio Quadrangle: 2008 Progress Report; Structural Maps of the V-17 Beta Regio Quadrangle, Venus; Geologic Mapping of Isabella Quadrangle (V-50) and Helen Planitia, Venus; Renewed Mapping of the Nepthys Mons Quadrangle (V-54), Venus; Mapping the Sedna-Lavinia Region of Venus; Geologic Mapping of the Guinevere Planitia Quadrangle of Venus; Geological Mapping of Fortuna Tessera (V-2): Venus and Earth's Archean Process Comparisons; Geological Mapping of the North Polar Region of Venus (V-1 Snegurochka Planitia): Significant Problems and Comparisons to the Earth's Archean; Venus Quadrangle Geological Mapping: Use of Geoscience Data Visualization Systems in Mapping and Training; Geologic Map of the V-1 Snegurochka Planitia Quadrangle: Progress Report; The Fredegonde (V-57) Quadrangle, Venus: Characterization of the Venus Midlands; Formation and Evolution of Lakshmi Planum (V-7), Venus: Assessment of Models using Observations from Geological Mapping; Geologic Map of the Meskhent Tessera Quadrangle (V-3), Venus: Evidence for Early Formation and Preservation of Regional Topography; Geological Mapping of the Lada Terra (V-56) Quadrangle, Venus: A Progress Report; Geology of the Lachesis Tessera Quadrangle (V-18), Venus; Geologic Mapping of the Juno Chasma Quadrangle, Venus: Establishing the Relation Between Rifting and Volcanism; Geologic Mapping of V-19, V-28, and V-53; Lunar Geologic Mapping Program: 2008 Update; Geologic Mapping of the Marius Quadrangle, the Moon; Geologic Mapping along the Arabia Terra Dichotomy Boundary: Mawrth Vallis and Nili Fossae, Mars: Introductory Report; New Geologic Map of the Argyre Region of Mars; Geologic Evolution of the Martian Highlands: MTMs -20002, -20007, -25002, and -25007; Mapping Hesperia Planum, Mars; Geologic Mapping of the Meridiani Region, Mars; Geology of Holden Crater and the Holden and Ladon Multi-Ring Impact Basins, Margaritifer Terra, Mars; Geologic Mapping of Athabasca Valles; Geologic Mapping of MTM -30247, -35247 and -40247 Quadrangles, Reull Vallis Region of Mars; Geologic Mapping of the Martian Impact Crater Tooting; Geology of the Southern Utopia Planitia Highland-Lowland Boundary Plain: First Year Results and Second Year Plan; Mars Global Geologic Mapping: Amazonian Results; Recent Geologic Mapping Results for the Polar Regions of Mars; Geologic Mapping of the Medusae Fossae Formation on Mars (MC-8 SE and MC-23 NW) and the Northern Lowlands of Venus (V-16 and V-15); Geologic Mapping of the Zal, Hi'iaka, and Shamshu Regions of Io; Global Geologic Map of Europa; Material Units, Structures/Landforms, and Stratigraphy for the Global Geologic Map of Ganymede (1:15M); and Global Geologic Mapping of Io: Preliminary Results.

Traffic monitoring with distributed smart cameras

NASA Astrophysics Data System (ADS)

Sidla, Oliver; Rosner, Marcin; Ulm, Michael; Schwingshackl, Gert

2012-01-01

The observation and monitoring of traffic with smart visions systems for the purpose of improving traffic safety has a big potential. Today the automated analysis of traffic situations is still in its infancy--the patterns of vehicle motion and pedestrian flow in an urban environment are too complex to be fully captured and interpreted by a vision system. 3In this work we present steps towards a visual monitoring system which is designed to detect potentially dangerous traffic situations around a pedestrian crossing at a street intersection. The camera system is specifically designed to detect incidents in which the interaction of pedestrians and vehicles might develop into safety critical encounters. The proposed system has been field-tested at a real pedestrian crossing in the City of Vienna for the duration of one year. It consists of a cluster of 3 smart cameras, each of which is built from a very compact PC hardware system in a weatherproof housing. Two cameras run vehicle detection and tracking software, one camera runs a pedestrian detection and tracking module based on the HOG dectection principle. All 3 cameras use sparse optical flow computation in a low-resolution video stream in order to estimate the motion path and speed of objects. Geometric calibration of the cameras allows us to estimate the real-world co-ordinates of detected objects and to link the cameras together into one common reference system. This work describes the foundation for all the different object detection modalities (pedestrians, vehicles), and explains the system setup, tis design, and evaluation results which we have achieved so far.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, Richard Parker, with NASA, watches a monitor showing images from a camera inserted beneath tiles of the orbiter Endeavour to inspect for corrosion.

NASA Image and Video Library

2003-09-04

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, Richard Parker, with NASA, watches a monitor showing images from a camera inserted beneath tiles of the orbiter Endeavour to inspect for corrosion.

Venus Express set for launch to the cryptic planet

NASA Astrophysics Data System (ADS)

2005-10-01

On Wednesday, 26 October 2005, the sky over the Baikonur Cosmodrome, Kazakhstan, will be illuminated by the blast from a Soyuz-Fregat rocket carrying this precious spacecraft aloft. The celestial motion of the planets in our Solar System has given Venus Express the window to travel to Venus on the best route. In fact, every nineteen months Venus reaches the point where a voyage from Earth is the most fuel-efficient. To take advantage of this opportunity, ESA has opted to launch Venus Express within the next ‘launch window’, opening on 26 October this year and closing about one month later, on 24 November. Again, due to the relative motion of Earth and Venus, plus Earth’s daily rotation, there is only one short period per day when it is possible to launch, lasting only a few seconds. The first launch opportunity is on 26 October at 06:43 Central European Summer Time (CEST) (10:43 in Baikonur). Venus Express will take only 163 days, a little more than five months, to reach Venus. Then, in April 2006, the adventure of exploration will begin with Venus finally welcoming a spacecraft, a fully European one, more than ten years after humankind paid the last visit. The journey starts at launch One of the most reliable launchers in the world, the Soyuz-Fregat rocket, will set Venus Express on course for its target. Soyuz, procured by the European/Russian Starsem company, consists of three main stages with an additional upper stage, Fregat, atop. Venus Express is attached to this upper stage. The injection of Venus Express into the interplanetary trajectory which will bring it to Venus consists of three phases. In the first nine minutes after launch, Soyuz will perform the first phase, that is an almost vertical ascent trajectory, in which it is boosted to about 190 kilometres altitude by its three stages, separating in sequence. In the second phase, the Fregat-Venus Express ‘block’, now free from the Soyuz, is injected into a circular parking orbit around Earth heading east. This injection is done by the first burn of the Fregat engine, due to take place at 06:52 CEST (04:52 GMT). At 08:03 CEST, about one hour and twenty minutes after lift-off and after an almost full circle around Earth, the third phase starts. While flying over Africa, Fregat will ignite for a second time to escape Earth orbit and head into the hyperbolic trajectory that will bring the spacecraft to Venus. After this burn, Fregat will gently release Venus Express, by firing a separation mechanism. With this last step, the launcher will have concluded its task. Plenty of ground activities for a successful trip Once separated from Fregat at 08:21 CEST, Venus Express will be awoken from its dormant status by a series of automatic on-board commands, such as the activation of its propulsion and thermal control systems, the deployment of solar arrays and manoeuvres to ‘orient’ itself in space. From this moment the spacecraft comes under the control of ESA’s European Space Operations Centre (ESOC) for the full duration of the mission. The flight control team co-ordinate and manage a network of ESA ground stations and antennas around the globe, to regularly communicate with the spacecraft. The New Norcia station in Australia and the Kourou station in French Guiana will in turn communicate with Venus Express in the initial phase of the mission. The first opportunity to receive a signal and confirm that the spacecraft is in good health will be the privilege of the New Norcia station about two hours after launch. In this early phase of the mission, once ESOC has taken full control of the satellite, the spacecraft will be fully activated. Operations will also include two burns of the Venus Express thrusters, to correct any possible error in the trajectory after separation from Fregat. On 28 October, the newly inaugurated Cebreros station in Spain, with its 35-metre antenna, will start to take an active part in ground network operations to relay information between ESOC and the spacecraft. During the cruise phase and once the spacecraft has arrived at Venus, Cebreros will be the main information relay point between ESOC and Venus Express. Reaching for Venus During its 163 day journey to Venus, Venus Express will cover about 400 million kilometres at an average speed of some 28 kilometres per second with respect to the Sun. After an initial commissioning period, the spacecraft will cruise peacefully with no specific operations planned, besides routine checks of its subsystems and scientific instruments, and minor trajectory corrections if needed. The thrills will start again on 6 April 2006, at the end of the cruise, when the spacecraft will have to perform a delicate manoeuvre to brake and be captured into orbit around Venus. The energy required for Venus Orbit Insertion (VOI) is very high, and will need the main engine to fire (burn) for approximately 51 minutes. This manoeuvre will place the spacecraft in a highly elliptical ‘capture’ orbit around the planet, with a pericentre (closest point to the Venusian surface) of 250 kilometres near the north pole, and an apocentre (furthest distance from the surface) at 350 000 kilometres roughly at the south pole. At the end of this initial 10-day ‘capture’ orbit, Venus Express will ignite its main engine again. About six days later, after a series of other minor orbit adjustments, the spacecraft will have been positioned in its final operational orbit. This will be an elliptical polar orbit, lying between 250 and 66 000 kilometres above Venus, and will last 24 hours. The capture orbit could already provide the first opportunity for scientific observations, but the nominal science phase will start on 4 July 2006, after the spacecraft and instruments commissioning phase has been concluded. The set of seven instruments on board Venus Express represents an unprecedented diagnostic package to study the thick and enigmatic atmosphere of Venus - an atmosphere so dense and so intimately coupled with the planet’s surface, that studying it will help provide clues about the features, status and evolution of the entire planet. Note to editors Venus Express is an almost identical twin spacecraft to Mars Express, but adapted to operate in the hot and harsh environment around Venus. It was built by EADS Astrium, Toulouse (France), leading a group of industrial partners throughout Europe. Completing the spacecraft took less than four years from concept to launch, making it the fastest-built ESA scientific satellite ever. Besides the spacecraft manufacturing and testing, industry will still be involved during the mission on a collaboration and consultancy basis for the ESA Venus Express Project team, led by the Project Manager, and for the Venus Express ground control team, led by the Spacecraft Operations Manager. On 4 July 2006, when the nominal science phase begins, the Venus Express Project Manager will hand over responsibility for the mission to an ESA Venus Express Mission Manager, leading the Venus Express Science Operations Centre (VSOC) in ESA’s European Space Research and Technology Centre (ESTEC) in the Netherlands. The VSOC performs the routine planning for scientific observations, in co-ordination with the Project Scientist and the instrument Principal Investigators. ESA’s investment in Venus Express amounts to about 220 million Euros, covering development of the spacecraft, launch and operations. This figure also includes 15 million Euros for instrument development, including support to several research institutes (Principal Investigators) for building the instruments. Venus Express is one of a family of missions in which costs are shared, the others being Rosetta and Mars Express.

FRET sensor-based quantification of intracellular trehalose in mammalian cells.

PubMed

Kikuta, Shingo; Hou, Bi-Huei; Sato, Ryoichi; Frommer, Wolf B; Kikawada, Takahiro

2016-01-01

Trehalose acts as a stress protectant and an autophagy inducer in mammalian cells. The molecular mechanisms of action remain obscure because intracellular trehalose at micromolar level is difficult to quantitate. Here, we show a novel trehalose monitoring technology based on FRET. FLIP-suc90μ∆1Venus sensor expressed in mammalian cells enables to quickly and non-destructively detect an infinitesimal amount of intracellular trehalose.

Equatorial flattenings of planets - Venus

NASA Astrophysics Data System (ADS)

Burša, M.; Šíma, Z.

1985-05-01

The dimensions of Venus were found in order to calculate the degree of flattening due to gravity. The calculations were carried out within the framework of the general flattening theory of Bursa and Sima (1969). Data on the gravitational field of Venus, obtained during observations by Mottinger and Williams (1983) were incorporated in the equations. It is shown that the figure of Venus is different from all terrestrial bodies in the solar system: the surface in the equatorial zone is located above the best-fitting triaxial Venus ellipsoid. Deflections of the vertical at the planet surface are given.

Magellan: The unveiling of Venus

NASA Technical Reports Server (NTRS)

1989-01-01

In the late 1970s and early 1980s, the United States and the Soviet Union sent the Pioneer Venus and Venera spacecraft, respectively, to study Venus more closely and to image its surface with radar. These missions have answered many questions about Venus, but many more questions remain unanswered about the extent to which Venus' surface was shaped by volcanoes, plate tectonics, impact craters, and water and wind erosion. To help answer these remaining questions a new radar imaging spacecraft Magellan will be launched from the Space Shuttle. Magellan will spend eight months mapping most of the planet at a resolution nearly ten times better than any previous views of the surface. The mission of Magellan, the radar equipment, orbiting of Venus, planetary imaging, and surface exploration are discussed.

Maritime microwave radar and electro-optical data fusion for homeland security

NASA Astrophysics Data System (ADS)

Seastrand, Mark J.

2004-09-01

US Customs is responsible for monitoring all incoming air and maritime traffic, including the island of Puerto Rico as a US territory. Puerto Rico offers potentially obscure points of entry to drug smugglers. This environment sets forth a formula for an illegal drug trade - based relatively near the continental US. The US Customs Caribbean Air and Marine Operations Center (CAMOC), located in Puntas Salinas, has the charter to monitor maritime and Air Traffic Control (ATC) radars. The CAMOC monitors ATC radars and advises the Air and Marine Branch of US Customs of suspicious air activity. In turn, the US Coast Guard and/or US Customs will launch air and sea assets as necessary. The addition of a coastal radar and camera system provides US Customs a maritime monitoring capability for the northwestern end of Puerto Rico (Figure 1). Command and Control of the radar and camera is executed at the CAMOC, located 75 miles away. The Maritime Microwave Surveillance Radar performs search, primary target acquisition and target tracking while the Midwave Infrared (MWIR) camera performs target identification. This wide area surveillance, using a combination of radar and MWIR camera, offers the CAMOC a cost and manpower effective approach to monitor, track and identify maritime targets.

Earth-orbiting extreme ultraviolet spectroscopic mission: SPRINT-A/EXCEED

NASA Astrophysics Data System (ADS)

Yoshikawa, I.; Tsuchiya, F.; Yamazaki, A.; Yoshioka, K.; Uemizu, K.; Murakami, G.; Kimura, T.; Kagitani, M.; Terada, N.; Kasaba, Y.; Sakanoi, T.; Ishii, H.; Uji, K.

2012-09-01

The EXCEED (Extreme Ultraviolet Spectroscope for Exospheric Dynamics) mission is an Earth-orbiting extreme ultraviolet (EUV) spectroscopic mission and the first in the SPRINT series being developed by ISAS/JAXA. It will be launched in the summer of 2013. EUV spectroscopy is suitable for observing tenuous gases and plasmas around planets in the solar system (e.g., Mercury, Venus, Mars, Jupiter, and Saturn). Advantage of remote sensing observation is to take a direct picture of the plasma dynamics and distinguish between spatial and temporal variability explicitly. One of the primary observation targets is an inner magnetosphere of Jupiter, whose plasma dynamics is dominated by planetary rotation. Previous observations have shown a few percents of the hot electron population in the inner magnetosphere whose temperature is 100 times higher than the background thermal electrons. Though the hot electrons have a significant impact on the energy balance in the inner magnetosphere, their generation process has not yet been elucidated. In the EUV range, a number of emission lines originate from plasmas distributed in Jupiter's inner magnetosphere. The EXCEED spectrograph is designed to have a wavelength range of 55-145 nm with minimum spectral resolution of 0.4 nm, enabling the electron temperature and ion composition in the inner magnetosphere to be determined. Another primary objective is to investigate an unresolved problem concerning the escape of the atmosphere to space. Although there have been some in-situ observations by orbiters, our knowledge is still limited. The EXCEED mission plans to make imaging observations of plasmas around Venus and Mars to determine the amounts of escaping atmosphere. The instrument's field of view (FOV) is so wide that we can get an image from the interaction region between the solar wind and planetary plasmas down to the tail region at one time. This will provide us with information about outward-flowing plasmas, e.g., their composition, rate, and dependence on solar activity. EXCEED has two mission instruments: the EUV spectrograph and a target guide camera that is sensitive to visible light. The EUV spectrograph is designed to have a wavelength range of 55-145 nm with a spectral resolution of 0.4-1.0 nm. The spectrograph slits have a FOV of 400 x 140 arcseconds (maximum). The optics of the instrument consists of a primary mirror with a diameter of 20cm, a laminar type grating, and a 5-stage micro-channel plate assembly with a resistive anode encoder. To achieve high efficiencies, the surfaces of the primary mirror and the grating are coated with CVD-SiC. Because of the large primary mirror and high efficiencies, good temporal resolution and complete spatial coverage for Io plasma torus observation is expected. Based on a feasibility study using the spectral diagnosis method, it is shown that EXCEED can determine the Io plasma torus parameters, such as the electron density, temperatures, hot electron fraction and so on, using an exposure time of 50 minutes. The target guide camera will be used to capture the target and guide the observation area of interest to the slit. Emissions from outside the slit's FOV will be reflected by the front of the slit and guided to the target guide camera. The guide camera's FOV is 240" x 240". The camera will take an image every 3 seconds and the image is sent to a mission data processor (MDP), which calculates the centroid of the image. During an observation, the bus system controls the attitude to keep the centroid position of the target in the guide camera with an accuracy of ±5 arc-seconds. With the help of the target guide camera, we will take spectral images with a long exposure time of 50 minutes and good spatial resolution of 20 arc-seconds.

Can Commercial Digital Cameras Be Used as Multispectral Sensors? A Crop Monitoring Test

PubMed Central

Lebourgeois, Valentine; Bégué, Agnès; Labbé, Sylvain; Mallavan, Benjamin; Prévot, Laurent; Roux, Bruno

2008-01-01

The use of consumer digital cameras or webcams to characterize and monitor different features has become prevalent in various domains, especially in environmental applications. Despite some promising results, such digital camera systems generally suffer from signal aberrations due to the on-board image processing systems and thus offer limited quantitative data acquisition capability. The objective of this study was to test a series of radiometric corrections having the potential to reduce radiometric distortions linked to camera optics and environmental conditions, and to quantify the effects of these corrections on our ability to monitor crop variables. In 2007, we conducted a five-month experiment on sugarcane trial plots using original RGB and modified RGB (Red-Edge and NIR) cameras fitted onto a light aircraft. The camera settings were kept unchanged throughout the acquisition period and the images were recorded in JPEG and RAW formats. These images were corrected to eliminate the vignetting effect, and normalized between acquisition dates. Our results suggest that 1) the use of unprocessed image data did not improve the results of image analyses; 2) vignetting had a significant effect, especially for the modified camera, and 3) normalized vegetation indices calculated with vignetting-corrected images were sufficient to correct for scene illumination conditions. These results are discussed in the light of the experimental protocol and recommendations are made for the use of these versatile systems for quantitative remote sensing of terrestrial surfaces. PMID:27873930

Don't get burned: thermal monitoring of vessel sealing using a miniature infrared camera

NASA Astrophysics Data System (ADS)

Lin, Shan; Fichera, Loris; Fulton, Mitchell J.; Webster, Robert J.

2017-03-01

Miniature infrared cameras have recently come to market in a form factor that facilitates packaging in endoscopic or other minimally invasive surgical instruments. If absolute temperature measurements can be made with these cameras, they may be useful for non-contact monitoring of electrocautery-based vessel sealing, or other thermal surgical processes like thermal ablation of tumors. As a first step in evaluating the feasibility of optical medical thermometry with these new cameras, in this paper we explore how well thermal measurements can be made with them. These cameras measure the raw flux of incoming IR radiation, and we perform a calibration procedure to map their readings to absolute temperature values in the range between 40 and 150 °C. Furthermore, we propose and validate a method to estimate the spatial extent of heat spread created by a cautery tool based on the thermal images.

Mission Architecture and Technology Options for a Flagship Class Venus In Situ Mission

NASA Technical Reports Server (NTRS)

Balint, Tibor S.; Kwok, Johnny H.; Kolawa, Elizabeth A.; Cutts, James A.; Senske, David A.

2008-01-01

Venus, as part of the inner triad with Earth and Mars, represents an important exploration target if we want to learn more about solar system formation and evolution. Comparative planetology could also elucidate the differences between the past, present, and future of these three planets, and can help with the characterization of potential habitable zones in our solar system and, by extension, extrasolar systems. A long lived in situ Venus mission concept, called the Venus Mobile Explorer, was prominently featured in NASA's 2006 SSE Roadmap and supported in the community White Paper by the Venus Exploration Analysis Group (VEXAG). Long-lived in situ missions are expected to belong to the largest (Flagship) mission class, which would require both enabling and enhancing technologies beside mission architecture options. Furthermore, extreme environment mitigation technologies for Venus are considered long lead development items and are expected to require technology development through a dedicated program. To better understand programmatic and technology needs and the motivating science behind them, in this fiscal year (FY08) NASA is funding a Venus Flaghip class mission study, based on key science and technology drivers identified by a NASA appointed Venus Science and Technology Definition Team (STDT). These mission drivers are then assembled around a suitable mission architecture to further refine technology and cost elements. In this paper we will discuss the connection between the final mission architecture and the connected technology drivers from this NASA funded study, which - if funded - could enable a future Flagship class Venus mission and potentially drive a proposed Venus technology development program.

Characterizing Volcanic Eruptions on Venus: Some Realistic (?) Scenarios

NASA Technical Reports Server (NTRS)

Stofan, E. R.; Glaze, L. S.; Grinspoon, D. H.

2011-01-01

When Pioneer Venus arrived at Venus in 1978, it detected anomalously high concentrations of SO2 at the top of the troposphere, which subsequently declined over the next five years. This decline in SO2 was linked to some sort of dynamic process, possibly a volcanic eruption. Observations of SO2 variability have persisted since Pioneer Venus. More recently, scientists from the Venus Express mission announced that the SPICAV (Spectroscopy for Investigation of Characteristics of the Atmosphere of Venus) instrument had measured varying amounts of SO2 in the upper atmosphere; VIRTIS (Visible and Infrared Thermal Imaging Spectrometer) measured no similar variations in the lower atmosphere (ESA, 4 April, 2008). In addition, Fegley and Prinn stated that venusian volcanoes must replenish SO2 to the atmosphere, or it would react with calcite and disappear within 1.9 my. Fegley and Tremain suggested an eruption rate on the order of approx 1 cubic km/year to maintain atmospheric SO2; Bullock and Grinspoon posit that volcanism must have occurred within the last 20-50 my to maintain the sulfuric acid/water clouds on Venus. The abundance of volcanic deposits on Venus and the likely thermal history of the planet suggest that it is still geologically active, although at rates lower than Earth. Current estimates of resurfacing rates range from approx 0.01 cubic km/yr to approx 2 cubic km/yr. Demonstrating definitively that Venus is still volcanically active, and at what rate, would help to constrain models of evolution of the surface and interior, and help to focus future exploration of Venus.

Revealing the face of Venus: Magellan

NASA Technical Reports Server (NTRS)

1993-01-01

An overview of the Magellan spacecraft and mission is presented. Topics covered include: a description of the Magellan spacecraft; Venus geology; Venus gravity; synthetic aperture radar; and radar sensing.

Venus analogues on the Earth's ocean floor(?): Volcanic terrains seen by SeaMARC 2 side scan sonar

NASA Technical Reports Server (NTRS)

Mouginis-Mark, P. J.; Fryer, P.; Hussong, D.; Zisk, S. H.

1984-01-01

The geology of Venus is discussed. The approximate age of the surface and the relative importance of large scale volcanic, tectonic and sedimentary processes are not known. Venus holds a very important role in comparative planetology. The investigation of comparable environments to Venus to test ideas of landform development on that planet are proposed.

Critical taper wedge mechanics of fold-and-thrust belts on Venus - Initial results from Magellan

NASA Technical Reports Server (NTRS)

Suppe, John; Connors, Chris

1992-01-01

Examples of fold-and-thrust belts from a variety of tectonic settings on Venus are introduced. Predictions for the mechanics of fold-and-thrust belts on Venus are examined on the basis of wedge theory, rock mechanics data, and currently known conditions on Venus. The theoretical predictions are then compared with new Magellan data.

Venus: A search for clues to early biological possibilities

NASA Technical Reports Server (NTRS)

Colin, Larry; Kasting, James F.

1992-01-01

The extensive evidence that there is no extant life on Venus is summarized. The current atmospheric environment, which is far too hostile by terrestrial standards to support life, is described. However, exobiologists are interested in the possibility of extinct life on Venus. The early history of Venus is discussed in terms of its ability to sustain life that may now be extinct.

Venus Mobile Explorer with RPS for Active Cooling: A Feasibility Study

NASA Technical Reports Server (NTRS)

Leifer, Stephanie D.; Green, Jacklyn R.; Balint, Tibor S.; Manvi, Ram

2009-01-01

We present our findings from a study to evaluate the feasibility of a radioisotope power system (RPS) combined with active cooling to enable a long-duration Venus surface mission. On-board power with active cooling technology featured prominently in both the National Research Council's Decadal Survey and in the 2006 NASA Solar System Exploration Roadmap as mission-enabling for the exploration of Venus. Power and cooling system options were reviewed and the most promising concepts modeled to develop an assessment tool for Venus mission planners considering a variety of future potential missions to Venus, including a Venus Mobile Explorer (either a balloon or rover concept), a long-lived Venus static lander, or a Venus Geophysical Network. The concepts modeled were based on the integration of General Purpose Heat Source (GPHS) modules with different types of Stirling cycle heat engines for power and cooling. Unlike prior investigations which reported on single point design concepts, this assessment tool allows the user to generate either a point design or parametric curves of approximate power and cooling system mass, power level, and number of GPHS modules needed for a "black box" payload housed in a spherical pressure vessel.

Plasma Waves in the Magnetosheath of Venus

NASA Technical Reports Server (NTRS)

Strangeway, Robert J.

1996-01-01

Research supported by this grant is divided into three basic topics of investigation. These are: (1) Plasma waves in the Venus magnetosheath, (2) Plasma waves in the Venus foreshock and solar wind, (3) plasma waves in the Venus nightside ionosphere and ionotail. The main issues addressed in the first area - Plasma waves in the Venus magnetosheath - dealt with the wave modes observed in the magnetosheath and upper ionosphere, and whether these waves are a significant source of heating for the topside ionosphere. The source of the waves was also investigated. In the second area - Plasma waves in the Venus foreshock and solar wind, we carried out some research on waves observed upstream of the planetary bow shock known as the foreshock. The foreshock and bow shock modify the ambient magnetic field and plasma, and need to be understood if we are to understand the magnetosheath. Although most of the research was directed to wave observations on the dayside of the planet, in the last of the three basic areas studied, we also analyzed data from the nightside. The plasma waves observed by the Pioneer Venus Orbiter on the nightside continue to be of considerable interest since they have been cited as evidence for lightning on Venus.

Purification and Characterization of Hemagglutinating Proteins from Poker-Chip Venus (Meretrix lusoria) and Corbicula Clam (Corbicula fluminea)

PubMed Central

Cheng, Chin-Fu; Hung, Shao-Wen; Chang, Yung-Chung; Chen, Ming-Hui; Chang, Chen-Hsuan; Tsou, Li-Tse; Tu, Ching-Yu; Lin, Yu-Hsing; Liu, Pan-Chen; Lin, Shiun-Long; Wang, Way-Shyan

2012-01-01

Hemagglutinating proteins (HAPs) were purified from Poker-chip Venus (Meretrix lusoria) and Corbicula clam (Corbicula fluminea) using gel-filtration chromatography on a Sephacryl S-300 column. The molecular weights of the HAPs obtained from Poker-chip Venus and Corbicula clam were 358 kDa and 380 kDa, respectively. Purified HAP from Poker-chip Venus yielded two subunits with molecular weights of 26 kDa and 29 kDa. However, only one HAP subunit was purified from Corbicula clam, and its molecular weight was 32 kDa. The two Poker-chip Venus HAPs possessed hemagglutinating ability (HAA) for erythrocytes of some vertebrate animal species, especially tilapia. Moreover, HAA of the HAP purified from Poker-chip Venus was higher than that of the HAP of Corbicula clam. Furthermore, Poker-chip Venus HAPs possessed better HAA at a pH higher than 7.0. When the temperature was at 4°C–10°C or the salinity was less than 0.5‰, the two Poker-chip Venus HAPs possessed better HAA compared with that of Corbicula clam. PMID:22666167

Robot Tracer with Visual Camera

NASA Astrophysics Data System (ADS)

Jabbar Lubis, Abdul; Dwi Lestari, Yuyun; Dafitri, Haida; Azanuddin

2017-12-01

Robot is a versatile tool that can function replace human work function. The robot is a device that can be reprogrammed according to user needs. The use of wireless networks for remote monitoring needs can be utilized to build a robot that can be monitored movement and can be monitored using blueprints and he can track the path chosen robot. This process is sent using a wireless network. For visual robot using high resolution cameras to facilitate the operator to control the robot and see the surrounding circumstances.

Was Venus the first habitable world of our solar system?

NASA Astrophysics Data System (ADS)

Way, M. J.; Del Genio, Anthony D.; Kiang, Nancy Y.; Sohl, Linda E.; Grinspoon, David H.; Aleinov, Igor; Kelley, Maxwell; Clune, Thomas

2016-08-01

Present-day Venus is an inhospitable place with surface temperatures approaching 750 K and an atmosphere 90 times as thick as Earth's. Billions of years ago the picture may have been very different. We have created a suite of 3-D climate simulations using topographic data from the Magellan mission, solar spectral irradiance estimates for 2.9 and 0.715 Gya, present-day Venus orbital parameters, an ocean volume consistent with current theory, and an atmospheric composition estimated for early Venus. Using these parameters we find that such a world could have had moderate temperatures if Venus had a prograde rotation period slower than ~16 Earth days, despite an incident solar flux 46-70% higher than Earth receives. At its current rotation period, Venus's climate could have remained habitable until at least 0.715 Gya. These results demonstrate the role rotation and topography play in understanding the climatic history of Venus-like exoplanets discovered in the present epoch.

Was Venus the First Habitable World of our Solar System?

PubMed

Way, M J; Del Genio, Anthony D; Kiang, Nancy Y; Sohl, Linda E; Grinspoon, David H; Aleinov, Igor; Kelley, Maxwell; Clune, Thomas

2016-08-28

Present-day Venus is an inhospitable place with surface temperatures approaching 750K and an atmosphere 90 times as thick as Earth's. Billions of years ago the picture may have been very different. We have created a suite of 3-D climate simulations using topographic data from the Magellan mission, solar spectral irradiance estimates for 2.9 and 0.715 Gya, present-day Venus orbital parameters, an ocean volume consistent with current theory, and an atmospheric composition estimated for early Venus. Using these parameters we find that such a world could have had moderate temperatures if Venus had a rotation period slower than ~16 Earth days, despite an incident solar flux 46-70% higher than Earth receives. At its current rotation period, Venus's climate could have remained habitable until at least 715 million years ago. These results demonstrate the role rotation and topography play in understanding the climatic history of Venus-like exoplanets discovered in the present epoch.

The VENUS/NWChem software package. Tight coupling between chemical dynamics simulations and electronic structure theory

NASA Astrophysics Data System (ADS)

Lourderaj, Upakarasamy; Sun, Rui; Kohale, Swapnil C.; Barnes, George L.; de Jong, Wibe A.; Windus, Theresa L.; Hase, William L.

2014-03-01

The interface for VENUS and NWChem, and the resulting software package for direct dynamics simulations are described. The coupling of the two codes is considered to be a tight coupling since the two codes are compiled and linked together and act as one executable with data being passed between the two codes through routine calls. The advantages of this type of coupling are discussed. The interface has been designed to have as little interference as possible with the core codes of both VENUS and NWChem. VENUS is the code that propagates the direct dynamics trajectories and, therefore, is the program that drives the overall execution of VENUS/NWChem. VENUS has remained an essentially sequential code, which uses the highly parallel structure of NWChem. Subroutines of the interface that accomplish the data transmission and communication between the two computer programs are described. Recent examples of the use of VENUS/NWChem for direct dynamics simulations are summarized.

A dynamic model of Venus's gravity field

NASA Technical Reports Server (NTRS)

Kiefer, W. S.; Richards, M. A.; Hager, B. H.; Bills, B. G.

1984-01-01

Unlike Earth, long wavelength gravity anomalies and topography correlate well on Venus. Venus's admittance curve from spherical harmonic degree 2 to 18 is inconsistent with either Airy or Pratt isostasy, but is consistent with dynamic support from mantle convection. A model using whole mantle flow and a high viscosity near surface layer overlying a constant viscosity mantle reproduces this admittance curve. On Earth, the effective viscosity deduced from geoid modeling increases by a factor of 300 from the asthenosphere to the lower mantle. These viscosity estimates may be biased by the neglect of lateral variations in mantle viscosity associated with hot plumes and cold subducted slabs. The different effective viscosity profiles for Earth and Venus may reflect their convective styles, with tectonism and mantle heat transport dominated by hot plumes on Venus and by subducted slabs on Earth. Convection at degree 2 appears much stronger on Earth than on Venus. A degree 2 convective structure may be unstable on Venus, but may have been stabilized on Earth by the insulating effects of the Pangean supercontinental assemblage.

The polar thermosphere of Venus

NASA Astrophysics Data System (ADS)

Mueller-Wodarg, Ingo; Rosenblatt, Pascal; Bruinsma, Sean; Yelle, Roger; Svedhem, Håkan; Forbes, Jeffrey M.; Withers, Paul; Keating Sci. Gerald, Sr.; Lopez-Valverde, Miguel Angel

The thermosphere of Venus has been extensively observed in-situ primarily by the Pioneer Venus Orbiter, but those measurements concentrated on the low latitude regions. Until recently, no in-situ observations were made of the polar thermosphere of Venus, and reference atmospheres such as the VTS3 and VIRA models relied on solar zenith angle trends inferred at low latitudes in order to extrapolate to polar latitudes. The Venus Express Atmospheric Drag Experiment (VExADE) carries out accurate orbital tracking in order to infer for the first time ever the densities in Venus' polar thermosphere near 180 km altitude at solar minimum. During 3 recent tracking campaigns we obtained density measurements that allow us to compare actual densities in those regions with those predicted by the reference atmosphere models. We constructed a hydrostatic diffusive equilibrium at-mosphere model that interpolates between the Venus Express remote sensing measurements in the upper mesosphere and lower thermosphere region and the in-situ drag measurements by VExADE. This paper will present and discuss our latest findings.

The tectonics of Venus: An overview

NASA Technical Reports Server (NTRS)

Solomon, Sean C.

1992-01-01

While the Pioneer Venus altimeter, Earth-based radar observatories, and the Venera 15-16 orbital imaging radars provided views of large-scale tectonic features on Venus at ever-increasing resolution, the radar images from Magellan constitute an improvement in resolution of at least an order of magnitude over the best previously available. A summary of early Magellan observations of tectonic features on Venus was published, but data available at that time were restricted to the first month of mapping and represented only about 15 percent of the surface of the planet. Magellan images and altimetry are now available for more than 95 percent of the Venus surface. Thus a more global perspective may be taken on the styles and distribution of lithospheric deformation on Venus and their implications for the tectonic history of the planet.

Venus in motion: An animated video catalog of Pioneer Venus Orbiter Cloud Photopolarimeter images

NASA Technical Reports Server (NTRS)

Limaye, Sanjay S.

1992-01-01

Images of Venus acquired by the Pioneer Venus Orbiter Cloud Photopolarimeter (OCPP) during the 1982 opportunity have been utilized to create a short video summary of the data. The raw roll by roll images were first navigated using the spacecraft attitude and orbit information along with the CPP instrument pointing information. The limb darkening introduced by the variation of solar illumination geometry and the viewing angle was then modelled and removed. The images were then projected to simulate a view obtained from a fixed perspective with the observer at 10 Venus radii away and located above a Venus latitude of 30 degrees south and a longitude 60 degrees west. A total of 156 images from the 1982 opportunity have been animated at different dwell rates.

Camera-Based Microswitch Technology to Monitor Mouth, Eyebrow, and Eyelid Responses of Children with Profound Multiple Disabilities

ERIC Educational Resources Information Center

Lancioni, Giulio E.; Bellini, Domenico; Oliva, Doretta; Singh, Nirbhay N.; O'Reilly, Mark F.; Lang, Russell; Didden, Robert

2011-01-01

A camera-based microswitch technology was recently used to successfully monitor small eyelid and mouth responses of two adults with profound multiple disabilities (Lancioni et al., Res Dev Disab 31:1509-1514, 2010a). This technology, in contrast with the traditional optic microswitches used for those responses, did not require support frames on…

Alternative images for perpendicular parking : a usability test of a multi-camera parking assistance system.

DOT National Transportation Integrated Search

2004-10-01

The parking assistance system evaluated consisted of four outward facing cameras whose images could be presented on a monitor on the center console. The images presented varied in the location of the virtual eye point of the camera (the height above ...

Venus Chasmata: A Lithospheric Stretching Model

NASA Technical Reports Server (NTRS)

Solomon, S. C.; Head, J. W.

1985-01-01

An outstanding problem for Venus is the characterization of its style of global tectonics, an issue intimately related to the dominant mechanism of lithospheric heat loss. Among the most spectacular and extensive of the major tectonic features on Venus are the chasmata, deep linear valleys generally interpreted to be the products of lithospheric extension and rifting. Systems of chasmata and related features can be traced along several tectonic zones up to 20,000 km in linear extent. A lithospheric stretching model was developed to explain the topographic characteristics of Venus chasmata and to constrain the physical properties of the Venus crust and lithosphere.

Refining the Workflow of UV Camera Measurements: Data Collection from Low Emission Rate Volcanoes under Variable Conditions

NASA Astrophysics Data System (ADS)

Brewer, I. D.; Werner, C. A.; Nadeau, P. A.

2010-12-01

UV camera systems are gaining popularity worldwide for quantifying SO2 column abundances and emission rates from volcanoes, which serve as primary measures of volcanic hazard and aid in eruption forecasting. To date many of the investigations have focused on fairly active and routinely monitored volcanoes under optimal conditions. Some recent studies have begun to recommend protocols and procedures for data collection, but additional questions still need to be addressed. In this study we attempt to answer these questions, and also present results from volcanoes that are rarely monitored. Conditions at these volcanoes are typically sub-optimal for UV camera measurements. Discussion of such data is essential in the assessment of the wider applicability of UV camera measurements for SO2 monitoring purposes. Data discussed herein consists of plume images from volcanoes with relatively low emission rates, with varying weather conditions and from various distances (2-12 km). These include Karangatang Volcano (Indonesia), Mount St. Helens (Washington, USA), and Augustine and Redoubt Volcanoes (Alaska, USA). High emission rate data were also collected at Kilauea Volcano (Hawaii, USA), and blue sky test images with no plume were collected at Mammoth Mountain (California, USA). All data were collected between 2008 and 2010 using both single-filter (307 nm) and dual-filter (307 nm/326 nm) systems and were accompanied by FLYSPEC measurements. With the dual-filter systems, both a filter wheel setup and a synchronous-imaging dual-camera setup were employed. Data collection and processing questions included (1) what is the detection limit of the camera, (2) how large is the variability in raw camera output, (3) how do camera optics affect the measurements and how can this be corrected, (4) how much variability is observed in calibration under various conditions, (5) what is the optimal workflow for image collection and processing, and (6) what is the range of camera operating conditions? Besides emission rates from these infrequently monitored volcanoes, the results of this study include a recommended workflow and procedure for image collection and calibration, and a MATLAB-based algorithm for batch processing, thereby enabling accurate emission rates at 1 Hz when a synchronous-imaging dual-camera setup is used.

On the tectonics of Venus

NASA Astrophysics Data System (ADS)

Arkani-Hamed, Jafar

1993-02-01

The thermal evolution and mechanical properties of a mechanical boundary layer of mantle convection are calculated for three Venus models—cold, Earth-like, and hot—with temperatures of 1300°C, 1400°C, and 1500°C, respectively at the base of their thermal boundary layers. The mechanical boundary layers consist of a basaltic crust with thicknesses of 3 km, 9 km, and 18 km, and depleted periodotitic mantle with thicknesses of 37 km, 65 km, and 90 km, respectively. The thin crust of the cold Venus model couples tightly to the underlying mantle and produces a single competent layer, whereas the thicker crust of the other models has a weak lower part that decouples the crust from the mantle. The characteristic wavelengths (10-20 km) of the banded terrains of tesserae surrounding Ishtar Terra can be explained by the buckling of the crusts of all three Venus models as long as their mechanical boundary layers are older than approximately 150 m.a., implying that the observed wavelengths provide no constraint on the thickness and age of the Venusian crust that is older than approximately 150 m.a. Shortening of the basaltic crust, however, cannot produce surface elevations higher than about 2 km on Venus, because basalt in the lower crust transforms to high-density eclogite, which sinks into the mantle. Therefore, Lakshmi Planum and the surrounding mountains probably contain lower-density material and are analogous to continental masses on the Earth. The ridge spacings of the northern ridge belt can be interpreted as being caused by faulting of the depleted mantle of the cold and Earth-like Venus models if the mechanical boundary layer is older than about 100 m.a. and 200 m.a., respectively. The hot model, however, cannot account for the formation of the ridge belt. Besides the characteristic wavelengths of the banded terrains and spacings of the ridge belts, the cold Venus model seems to account for many other features on Venus. The dynamic support of the surface topography of tesserae requires a convergence velocity of less than 0.1 cm year -1 for the mechanical boundary layer of the cold Venus model. This very low velocity is supported by the spatially random distribution of craters on Venus. Furthermore, the lack of pervasive volcanism on Venus in approximately the last 500 m.y., the lack of an internal magnetic field of Venus, and the lack of an oceanic type ridge system on Venus support the cold Venus model.

Importance of Including Topography in Numerical Simulations of Venus' Atmospheric Circulation

NASA Astrophysics Data System (ADS)

Parish, H. F.; Schubert, G.; Lebonnois, S.; Covey, C. C.; Walterscheid, R. L.; Grossman, A.

2012-12-01

Venus' atmosphere is characterized by strong superrotation, in which the wind velocities at cloud heights are around 60 times faster than the surface rotation rate. The reasons for this strong superrotation are still not well understood. Since the surface of the planet is both a source and sink of atmospheric angular momentum it is important to understand and properly account for the interactions at the surface-atmosphere boundary. A key aspect of the surface-atmosphere interaction is the topography. Topography has been introduced into different general circulation models (GCMs) of Venus' atmosphere, producing significant, but widely varying effects on the atmospheric circulation. The reasons for the inconsistencies among model results are not well known, but our studies suggest they might be related to the influences of different dynamical cores. In our recent study, we have analyzed the angular momentum budget for two Venus GCMs, the Venus Community Atmosphere model (Venus CAM) and the Laboratoire de Meteorologie Dynamique (LMD) Venus GCM. Because of Venus' low magnitude surface winds, surface friction alone supplies only a relatively weak angular momentum forcing to the atmosphere. We find that if surface friction is introduced without including surface topography, the angular momentum balance of the atmosphere may be dominated by effects such as numerical diffusion, a sponge layer, or other numerical residuals that are generally included in all GCMs, and can themselves be sources of angular momentum. However, we find the mountain torque associated with realistic Venus surface topography supplies a much larger source of angular momentum than the surface friction, and dominates nonphysical numerical terms. (A similar effect occurs for rapidly rotating planets like Earth, but in this case numerical errors in the angular momentum budget are relatively small even in the absence of mountain torque). Even if surface friction dominates numerical terms in the angular momentum budgets of simulations without realistic topography, it must be remembered that there are no observational constraints on model parameterizations of the real surface friction on Venus. It is essential for a planet such as Venus, for which surface friction alone supplies only weak angular momentum forcing, to include surface topography to generate realistic forcing of angular momentum and avoid the influences of numerical artifacts, which can be significant. Venus' topography, as mapped using measurements from the Magellan mission, shows significant hemispheric asymmetry. In this work we examine the impact of this asymmetry using simulations of Venus' circulation with and without topography, within the latest version of the Venus CAM GCM.

Venus: Mysteries Of The "forgotten Planet"

NASA Astrophysics Data System (ADS)

Titov, D. V.

The first phase of Venus spacecraft exploration by the Venera, Pioneer Venus, Vega and Magellan missions and later Galileo and Cassini fly-bys established a basic de- scription of the physical and chemical conditions prevailing in the atmosphere and near-planetary environment. It also expanded considerably our knowledge of VenusS geology and geophysics. At the same time, these studies raised many questions on the physical processes on the planet, most of which remain as of today unsolved. The fundamental mysteries of Venus are related to the global atmospheric circulation, the atmospheric chemical composition and its variations, the surface-atmosphere physical and chemical interactions including volcanism, the physics and chemistry of the cloud layer, the thermal balance and role of trace gases in the greenhouse effect, the origin and evolution of the atmosphere, and the plasma environment and its interaction with the solar wind. Besides, the key issues of the history of Venusian volcanism, the global tectonic structure of Venus, and important characteristics of the planetSs surface are still unresolved. Beyond the specific case of Venus, resolving these issues is of cru- cial importance in a comparative planetology context and notably for understanding the long-term climatic evolution processes on Earth. The above problems can be effi- ciently addressed by an orbiter equipped with a suite of adequate remote sensing and in situ instruments. A combination of spectrometers, spectro-imagers, and imagers covering the UV to thermal IR range, along with other instruments such as a radar and a plasma and neutral atoms analyzer, is able to sound the entire Venus atmosphere from the surface to 200 km, and to address specific questions on the surface. Future in situ investigations by descent probes, balloons, and sample return missions will be required to provide a more detailed insight in the Venus mysteries. For more than 10 years Venus has remained the Sforgotten planetT: none of the worldSs space agencies & cedil; has considered it as a primary target. However, a great number of unsolved funda- mental problems in VenusS physics and availability of observational tools encourages the scientific community to propose missions to the planet. Venus Express in Europe and a set of Discovery missions in USA are being currently considered for inclusion in the programmes of space agencies. The Venus Orbiter mission has been recently approved in Japan.

Venus

ERIC Educational Resources Information Center

Martin, Paula; Stofan, Ellen

2004-01-01

On 8 June 2004 Venus will pass in front of the Sun as seen from the Earth. Many people will watch the small dark dot cross the solar disk, but will they stop to think about Venus as a real place? In this article we discuss what we know about Venus, what it looks like from orbit, what you might see if you were on the surface and future plans for…

Venus

NASA Astrophysics Data System (ADS)

Fegley, B., Jr.

2003-12-01

Venus is Earth's nearest planetary neighbor, and has fascinated mankind since the dawn of history. Venus' clouds reflect most of the sunlight shining on the planet and make it the brightest object in the sky after the Sun and Moon. Venus is visible with the naked eye as an evening star until a few hours after sunset, or as a morning star shortly before sunrise. Many ancient civilizations observed and worshipped Venus, which had a different name in each society, e.g., Ishtar to the Babylonians, Aphrodite to the Greeks, Tai'pei to the Chinese, and Venus to the Romans (Hunt and Moore, 1982). Venus has continued to play an important role in myth, literature, and science throughout history. In the early seventeenth century, Galileo's observations of the phases of Venus showed that the geocentric (Ptolemaic) model of the solar system was wrong and that the heliocentric (Copernican) model was correct. About a century later, Edmund Halley proposed that the distance from the Earth to the Sun (which was then unknown and is defined as one astronomical unit, AU) could be measured by observing transits of Venus across the Sun. These transits occur in pairs separated by eight years at intervals of 105.5 yr and 121.5 yr in an overall cycle of 243 yr, e.g., June 6, 1761, June 3, 1769; December 9, 1874, December 6, 1882, June 8, 2004, June 6, 2012, December 11, 2117, and December 8, 2125. The first attempted measurements of the astronomical unit during the 1761 transit were unsuccessful. However, several observers reported a halo around Venus as it entered and exited the Sun's disk. Thomas Bergman in Uppsala and Mikhail Lomonosov in St. Petersburg, independently speculated that the halo was due to an atmosphere on Venus. Eight years later observations of the 1769 solar transit (including those made by Captain Cook's expedition to Tahiti) gave a value of 1 AU=153 million kilometers, ~2.3% larger than the actual size (149.6 million kilometers) of the astronomical unit (Woolf, 1959; Maor, 2000).

Groundbased near-IR observations of the surface of Venus

NASA Technical Reports Server (NTRS)

Meadows, V. S.; Crisp, D.; Allen, D. A.

1992-01-01

We present images of the nightside of Venus taken in the near-infrared windows at 1.0, 1.1, 1.18, 1.28, 1.31, and 2.3 microns with the new infrared camera/spectrometer IRIS on the Anglo-Australian Telescope. These data were taken in spectral-mapping mode. This technique involves scanning the telescope perpendicular to the slit, while collecting spectra at successive slit positions across the planet. We produce data cubes with one spectral and two spatial dimensions. Images can be extracted over any wavelength regions. Each image has square pixels of 0.8 inch resolution. We reduced the scattered light from the sunlit crescent in images extracted from each window by subtracting images taken on either side of the window, where the Venus atmosphere is opaque. Unlike the short wavelength windows, which reveal thermal contrasts that originate primarily from the surface and deep atmosphere, the emission in the 2.3 microns window is produced at much higher altitudes (30-40 km). Emission contrasts seen near 2.3 microns are associated with horizontal variations in the cloud optical depths, and have rotation periods of about six days. We detect large contrasts in infrared emission (20-40 percent) across the disc of Venus in the 1.0-, 1.1-, 1.18-, 1.28-, and 1.31-micron images. Contrasts at these wavelengths may be due to a combination of variations in the optical depths of the overlying sulfuric acid clouds and differences in surface emission. Comparison with the 2.3-micron images show that the patterns seen in the 1.28- and 1.31-micron windows are consistent with cloud optical depth variations alone and require no contribution from the surface. However, images at 1.0, 1.1, and 1.8 microns from July 1991 show a dark feature having a contrast that increases with decreasing wavelength. This behavior is contrary to that expected of cloud absorption. Images taken on three successive days in October show another dark feature that is stationary with respect to the surface. These regions of lower emission correspond closely to the high-altitude surface regions of Beta Regio and Aphrodite Terra. The images can potentially reveal the near-infrared emissiveity of the surface of Venus, thereby complementing Magellan radar reflectivity and ground based radio emissivity measurements. The contrast ratio between highlands and plains is much smaller than would be expected for blackbody radiation from the surface along. Unlike at radio wavelengths, where the atmosphere is essentially transparent, at near-infrared wavelengths the atmosphere emits, absorbs, and scatters radiation, and can modify the observed topographically induced contrasts. The additional radiation from the atmosphere reduces the contrast, and further modification would be expected if terrain at different altitudes has different emissivities. A fit to our data therefore requires, and may constrain, a model of the lowest scale height of the atmosphere.

Exploring Venus interior structure with infrasonic techniques

NASA Astrophysics Data System (ADS)

Mimoun, David; Garcia, Raphael; Cadu, Alexandre; Cutts, Jim; Komjathy, Attila; Pauken, Mike; Kedar, Sharon; Jackson, Jennifer; Stevenson, Dave

2017-04-01

Radar images have revealed a surface of Venus that is much younger than expected, as well as a variety of enigmatic features linked to the tectonic activity. If probing the interior structure of Venus is a formidable challenge, it is still of primary importance for understanding Venus itself, its relationship to Earth and more generally the evolution of Earth-like planets. Conventional long period seismology uses very broadband seismic sensors that require to be in contact with the planetary surface, like for the Apollo missions and for the Mars Insight mission; this approach is in the short term impractical for Venus because of its extreme temperature and pressure surface conditions. Russian probes such as Venera 13-14 have only lasted a few tens of minutes, when the required duration of the seismic measurements, based on a rough estimate of the Venus tectonic activity, is at least of a few months. We propose as a possible way forward to use the very conditions at the surface of Venus to record the signal in a more suitable environment: as acoustic and infrasonic waves resulting from seismic activity are coupled much more efficiently than on Earth in the dense carbon dioxide atmosphere, a string of micro-barometers deployed on a tether by a balloon platform at Venus over the cloud layer would record this infrasonic counterpart. Such an experiment could encompass a wide range of scientific objectives, from the characterization of the infrasonic background of Venus to the ability to record, and possibly discriminate, signatures from volcanic events, storm activity, and meteor impacts. We will discuss our proposed Venus experiment, as well as the experimental validation effort that takes place on Earth to validate the idea and possibly record infrasonic seismic counterparts

The orbital evolution of the Apollo asteroid group over 11,550 years

NASA Astrophysics Data System (ADS)

Zausaev, A. F.; Pushkarev, A. N.

1992-08-01

The Everhard method was used to monitor the orbital evolution of 20 Apollo asteroids in the time interval from 2250 A.D. to 9300 B.C. The closest encounters with large planets in the evolution process are calculated. Stable resonances with Venus and Earth over the period from 2250 A.D. to 9300 B.C. are obtained. Theoretical coordinates of radiants on initial and final moments of integration are calculated.

Beam measurements using visible synchrotron light at NSLS2 storage ring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Weixing, E-mail: chengwx@bnl.gov; Bacha, Bel; Singh, Om

2016-07-27

Visible Synchrotron Light Monitor (SLM) diagnostic beamline has been designed and constructed at NSLS2 storage ring, to characterize the electron beam profile at various machine conditions. Due to the excellent alignment, SLM beamline was able to see the first visible light when beam was circulating the ring for the first turn. The beamline has been commissioned for the past year. Besides a normal CCD camera to monitor the beam profile, streak camera and gated camera are used to measure the longitudinal and transverse profile to understand the beam dynamics. Measurement results from these cameras will be presented in this paper.more » A time correlated single photon counting system (TCSPC) has also been setup to measure the single bunch purity.« less

First results of the multi-purpose real-time processing video camera system on the Wendelstein 7-X stellarator and implications for future devices

NASA Astrophysics Data System (ADS)

Zoletnik, S.; Biedermann, C.; Cseh, G.; Kocsis, G.; König, R.; Szabolics, T.; Szepesi, T.; Wendelstein 7-X Team

2018-01-01

A special video camera has been developed for the 10-camera overview video system of the Wendelstein 7-X (W7-X) stellarator considering multiple application needs and limitations resulting from this complex long-pulse superconducting stellarator experiment. The event detection intelligent camera (EDICAM) uses a special 1.3 Mpixel CMOS sensor with non-destructive read capability which enables fast monitoring of smaller Regions of Interest (ROIs) even during long exposures. The camera can perform simple data evaluation algorithms (minimum/maximum, mean comparison to levels) on the ROI data which can dynamically change the readout process and generate output signals. Multiple EDICAM cameras were operated in the first campaign of W7-X and capabilities were explored in the real environment. Data prove that the camera can be used for taking long exposure (10-100 ms) overview images of the plasma while sub-ms monitoring and even multi-camera correlated edge plasma turbulence measurements of smaller areas can be done in parallel. These latter revealed that filamentary turbulence structures extend between neighboring modules of the stellarator. Considerations emerging for future upgrades of this system and similar setups on future long-pulse fusion experiments such as ITER are discussed.

An overview of the Soviet Vega balloon experiment and studies of the atmosphere of Venus

NASA Technical Reports Server (NTRS)

Sagdeev, R. Z.

1986-01-01

An overview of the VEGA probe to Venus is given, including a detailed examination of the balloon experiment to study the atmosphere of Venus. The areas of study include the ground network, the global network of radiotelescopes, meteorological measurements, the thermal structure of the Venus atmosphere in the middle cloud layer, atmospheric dynamics, and other results of the VEGA 1 and 2 experiments.

Venus's winds and temperatures during the MESSENGER's flyby: towards a three-dimensional instantaneous state of the atmosphere

NASA Astrophysics Data System (ADS)

Peralta, J.; Lee, Y. J.; Hueso, R.; Clancy, R. T.; Sandor, B. J.; Sánchez-Lavega, A.; Lellouch, E.; Rengel, M.; Machado, P.; Omino, M.; Piccialli, A.; Imamura, T.; Horinouchi, T.; Murakami, S.; Ogohara, K.; Luz, D.; Peach, D.

2017-09-01

The atmosphere of the Earth or Mars globally rotates with a speed similar to the rotation of the planet (approximately 24 h). The rotation of Venus is of about 243 days, much slower than the Earth, but when scientists measured the winds by tracking the clouds of Venus, they discovered that the atmosphere rotates 60 times faster! No one has explained yet what originates this "superrotation", and we do not know well what happens either above or below the clouds. The technique of "Doppler shift" has been used to measure winds above the clouds, but results are "chaotic" and different to interpret. Thanks to a worldwide collaboration in June 2007 between NASA (MESSENGER), ESA (Venus Express), and many observatories (VLT in Chile, JCMT in Hawaii, HHSMT in Arizona, or IRAM in Spain), the authors combined the different data to obtain, for the first time, the instantaneous 3-D structure of the winds on Venus at the clouds and also above, very important for new Venus models to start "forecasts" of the Venus weather with "data assimilation". We also discovered that the superrotation seems unexpectedly different on the night of Venus and that it varies its altitude depending on the day.

Transit of Venus Culture: A Celestial Phenomenon Intrigues the Public

NASA Astrophysics Data System (ADS)

Bueter, Chuck

2012-01-01

When Jeremiah Horrocks first observed it in 1639, the transit of Venus was a desirable telescopic target because of its scientific value. By the next transit of Venus in 1761, though, the enlightened public also embraced it as a popular celestial phenomenon. Its stature elevated over the centuries, the transit of Venus has been featured in music, poetry, stamps, plays, books, and art. The June 2004 transit emerged as a surprising global sensation, as suggested by the search queries it generated. Google's Zeitgeist deemed Venus Transit to be the #1 Most Popular Event in the world for that month. New priorities, technologies, and media have brought new audiences to the rare alignment. As the 2012 transit of Venus approaches, the trend continues with publicly accessible capabilities that did not exist only eight years prior. For example, sites from which historic observations have been made are plotted and readily available on Google Earth. A transit of Venus phone app in development will, if fully funded, facilitate a global effort to recreate historic expeditions by allowing smartphone users to submit their observed transit timings to a database for quantifying the Astronomical Unit. While maintaining relevance in modern scientific applications, the transit of Venus has emerged as a cultural attraction that briefly intrigues the mainstream public and inspires their active participation in the spectacle.

High Altitude Venus Operational Concept (HAVOC): Proofs of Concept

NASA Technical Reports Server (NTRS)

Jones, Christopher A.; Arney, Dale C.; Bassett, George Z.; Clark, James R.; Hennig, Anthony I.; Snyder, Jessica C.

2015-01-01

The atmosphere of Venus is an exciting destination for both further scientific study and future human exploration. A recent internal NASA study of a High Altitude Venus Operational Concept (HAVOC) led to the development of an evolutionary program for the exploration of Venus, with focus on the mission architecture and vehicle concept for a 30-day crewed mission into Venus's atmosphere at 50 kilometers. Key technical challenges for the mission include performing the aerocapture maneuvers at Venus and Earth, inserting and inflating the airship at Venus during the entry sequence, and protecting the solar panels and structure from the sulfuric acid in the atmosphere. Two proofs of concept were identified that would aid in addressing some of the key technical challenges. To mitigate the threat posed by the sulfuric acid ambient in the atmosphere of Venus, a material was needed that could protect the systems while being lightweight and not inhibiting the performance of the solar panels. The first proof of concept identified candidate materials and evaluated them, finding FEP-Teflon (Fluorinated Ethylene Propylene-Teflon) to maintain 90 percent transmittance to relevant spectra even after 30 days of immersion in concentrated sulfuric acid. The second proof of concept developed and verified a packaging algorithm for the airship envelope to inform the entry, descent, and inflation analysis.

Webcam network and image database for studies of phenological changes of vegetation and snow cover in Finland, image time series from 2014 to 2016

NASA Astrophysics Data System (ADS)

Peltoniemi, Mikko; Aurela, Mika; Böttcher, Kristin; Kolari, Pasi; Loehr, John; Karhu, Jouni; Linkosalmi, Maiju; Melih Tanis, Cemal; Tuovinen, Juha-Pekka; Nadir Arslan, Ali

2018-01-01

In recent years, monitoring of the status of ecosystems using low-cost web (IP) or time lapse cameras has received wide interest. With broad spatial coverage and high temporal resolution, networked cameras can provide information about snow cover and vegetation status, serve as ground truths to Earth observations and be useful for gap-filling of cloudy areas in Earth observation time series. Networked cameras can also play an important role in supplementing laborious phenological field surveys and citizen science projects, which also suffer from observer-dependent observation bias. We established a network of digital surveillance cameras for automated monitoring of phenological activity of vegetation and snow cover in the boreal ecosystems of Finland. Cameras were mounted at 14 sites, each site having 1-3 cameras. Here, we document the network, basic camera information and access to images in the permanent data repository (http://www.zenodo.org/communities/phenology_camera/). Individual DOI-referenced image time series consist of half-hourly images collected between 2014 and 2016 (https://doi.org/10.5281/zenodo.1066862). Additionally, we present an example of a colour index time series derived from images from two contrasting sites.

Atmospheric tides on Venus. III - The planetary boundary layer

NASA Technical Reports Server (NTRS)

Dobrovolskis, A. R.

1983-01-01

Diurnal solar heating of Venus' surface produces variable temperatures, winds, and pressure gradients within a shallow layer at the bottom of the atmosphere. The corresponding asymmetric mass distribution experiences a tidal torque tending to maintain Venus' slow retrograde rotation. It is shown that including viscosity in the boundary layer does not materially affect the balance of torques. On the other hand, friction between the air and ground can reduce the predicted wind speeds from about 5 to about 1 m/sec in the lower atmosphere, more consistent with the observations from Venus landers and descent probes. Implications for aeolian activity on Venus' surface and for future missions are discussed.

Mariner-Venus 1967

NASA Technical Reports Server (NTRS)

1971-01-01

Detailed information on the spacecraft performance, mission operations, and tracking and data acquisition is presented for the Mariner Venus 1967 and Mariner Venus 1967 extension projects. Scientific and engineering results and conclusions are discussed, and include the scientific mission, encounter with Venus, observations near Earth, and cruise phase of the mission. Flight path analysis, spacecraft subsystems, and mission-related hardware and computer program development are covered. The scientific experiments carried by Mariner 5 were ultraviolet photometer, solar plasma probe, helium magnetometer, trapped radiation detector, S-band radio occultation, dual-frequency radio propagation, and celestial mechanics. The engineering experience gained by converting a space Mariner Mars 1964 spacecraft into one flown to Venus is also described.

An Improved 360 Degree and Order Model of Venus Topography

NASA Technical Reports Server (NTRS)

Rappaport, Nicole J.; Konopliv, Alex S.; Kucinskas, Algis B.; Ford, Peter G.

1999-01-01

We present an improved 360 degree and order spherical harmonic solution for Venus' topography. The new model uses the most recent set of Venus altimetry data with spacecraft positions derived from a recent high resolution gravity model. Geometric analysis indicates that the offset between the center of mass and center of figure of Venus is about 10 times smaller than that for the Earth, the Moon, or Mars. Statistical analyses confirm that the RMS topography follows a power law over the central part of the spectrum. Compared to the previous topography model, the new model is more highly correlated with Venus' harmonic gravity field.

Spatial and temporal variations of the ion velocity measured in the Venus ionosphere

NASA Technical Reports Server (NTRS)

Miller, K. L.; Knudsen, W. C.

1987-01-01

Temporal and spatial deviations of ion velocity from the dominant flow of the Venusian ionosphere were detected in data collected from a retarding potential analyzer (RPA) aboard the Pioneer-Venus orbiter spectrometer. The ion velocity measurements were analyzed for the first 3.5 Venus years of the Pioneer-Venus mission, approximately through orbit 780. The deviations of ion velocity from the dominant velocity of the Venusian ionosphere, which generally flows nightward and is almost symmetric about the sun-Venus axis, affect both the ionospheric structure and dynamics. Two examples of departure from steady symmetric flow that were measured by the RPA are discussed.

Can we detect, monitor, and characterize volcanic activity using 'off the shelf' webcams and low-light cameras?

NASA Astrophysics Data System (ADS)

Harrild, M.; Webley, P. W.; Dehn, J.

2015-12-01

The ability to detect and monitor precursory events, thermal signatures, and ongoing volcanic activity in near-realtime is an invaluable tool. Volcanic hazards often range from low level lava effusion to large explosive eruptions, easily capable of ejecting ash to aircraft cruise altitudes. Using ground based remote sensing to detect and monitor this activity is essential, but the required equipment is often expensive and difficult to maintain, which increases the risk to public safety and the likelihood of financial impact. Our investigation explores the use of 'off the shelf' cameras, ranging from computer webcams to low-light security cameras, to monitor volcanic incandescent activity in near-realtime. These cameras are ideal as they operate in the visible and near-infrared (NIR) portions of the electromagnetic spectrum, are relatively cheap to purchase, consume little power, are easily replaced, and can provide telemetered, near-realtime data. We focus on the early detection of volcanic activity, using automated scripts that capture streaming online webcam imagery and evaluate each image according to pixel brightness, in order to automatically detect and identify increases in potentially hazardous activity. The cameras used here range in price from 0 to 1,000 and the script is written in Python, an open source programming language, to reduce the overall cost to potential users and increase the accessibility of these tools, particularly in developing nations. In addition, by performing laboratory tests to determine the spectral response of these cameras, a direct comparison of collocated low-light and thermal infrared cameras has allowed approximate eruption temperatures to be correlated to pixel brightness. Data collected from several volcanoes; (1) Stromboli, Italy (2) Shiveluch, Russia (3) Fuego, Guatemala (4) Popcatépetl, México, along with campaign data from Stromboli (June, 2013), and laboratory tests are presented here.

The extreme ultraviolet spectroscope for planetary science, EXCEED

NASA Astrophysics Data System (ADS)

Yoshioka, K.; Murakami, G.; Yamazaki, A.; Tsuchiya, F.; Kagitani, M.; Sakanoi, T.; Kimura, T.; Uemizu, K.; Uji, K.; Yoshikawa, I.

2013-09-01

The extreme ultraviolet spectroscope EXtrem ultraviolet spetrosCope for ExosphEric Dynamics (EXCEED) on board the SPRINT-A mission will be launched in the summer of 2013 by the new Japanese solid propulsion rocket Epsilon as its first attempt, and it will orbit around the Earth with an orbital altitude of around 1000 km. EXCEED is dedicated to and optimized for observing the terrestrial planets Mercury, Venus and Mars, as well as Jupiter for several years. The instrument consists of an off axis parabolic entrance mirror, switchable slits with multiple filters and shapes, a toroidal grating, and a photon counting detector, together with a field of view guiding camera. The design goal is to achieve a large effective area but with high spatial and spectral resolution. In this paper, the performance of each optical component will be described as determined from the results of test evaluation of flight models. In addition, the results of the optical calibration of the overall instrument are also shown. As a result, the spectral resolution of EXCEED is found to be 0.3-0.5 nm Full Width at Half Maximum (FWHM) over the entire spectral band (52-148 nm) and the spatial resolution achieve was 10". The evaluated effective area is around 3 cm2. Based on these specifications, the possibility of EXCEED detecting atmospheric ions or atoms around Mercury, Venus, and Mars will be discussed. In addition, we estimate the spectra that might be detected from the Io plasma torus around Jupiter for various hypothetical plasma parameters.

Development of camera technology for monitoring nests. Chapter 15

Treesearch

W. Andrew Cox; M. Shane Pruett; Thomas J. Benson; Scott J. Chiavacci; Frank R., III Thompson

2012-01-01

Photo and video technology has become increasingly useful in the study of avian nesting ecology. However, researchers interested in using camera systems are often faced with insufficient information on the types and relative advantages of available technologies. We reviewed the literature for studies of nests that used cameras and summarized them based on study...

MESSENGER and Venus Express Observations of the Near-tail of Venus: Magnetic Flux Transport, Current Sheet Structure, and Flux Rope Formation

NASA Technical Reports Server (NTRS)

Slavin, James A.; Boardsen, S. A.; Sarantos, M.; Acuna, M. H.; Anderson, B. J.; Barabash, S.; Benna, M.; Fraenz, M.; Gloeckler, G.; Gold, R. E.;

Efficacy of time-lapse photography and repeated counts abundance estimation for white-tailed deer populations

USGS Publications Warehouse

Keever, Allison; McGowan, Conor P.; Ditchkoff, Stephen S.; Acker, S.A.; Grand, James B.; Newbolt, Chad H.

2017-01-01

Automated cameras have become increasingly common for monitoring wildlife populations and estimating abundance. Most analytical methods, however, fail to account for incomplete and variable detection probabilities, which biases abundance estimates. Methods which do account for detection have not been thoroughly tested, and those that have been tested were compared to other methods of abundance estimation. The goal of this study was to evaluate the accuracy and effectiveness of the N-mixture method, which explicitly incorporates detection probability, to monitor white-tailed deer (Odocoileus virginianus) by using camera surveys and a known, marked population to collect data and estimate abundance. Motion-triggered camera surveys were conducted at Auburn University’s deer research facility in 2010. Abundance estimates were generated using N-mixture models and compared to the known number of marked deer in the population. We compared abundance estimates generated from a decreasing number of survey days used in analysis and by time periods (DAY, NIGHT, SUNRISE, SUNSET, CREPUSCULAR, ALL TIMES). Accurate abundance estimates were generated using 24 h of data and nighttime only data. Accuracy of abundance estimates increased with increasing number of survey days until day 5, and there was no improvement with additional data. This suggests that, for our system, 5-day camera surveys conducted at night were adequate for abundance estimation and population monitoring. Further, our study demonstrates that camera surveys and N-mixture models may be a highly effective method for estimation and monitoring of ungulate populations.

Venus Global Reference Atmospheric Model Status and Planned Updates

NASA Astrophysics Data System (ADS)

Justh, H. L.; Dwyer Cianciolo, A. M.

2017-05-01

Details the current status of Venus Global Reference Atmospheric Model (Venus-GRAM). Provides new sources of data and upgrades that need to be incorporated to maintain credibility and identifies options and features that could increase capability.

Tectonic History of the Terrestrial Planets

NASA Technical Reports Server (NTRS)

Solomon, Sean C.

1993-01-01

The topics covered include the following: patterns of deformation and volcanic flows associated with lithospheric loading by large volcanoes on Venus; aspects of modeling the tectonics of large volcanoes on the terrestrial planets; state of stress, faulting, and eruption characteristics of large volcanoes on Mars; origin and thermal evolution of Mars; geoid-to-topography ratios on Venus; a tectonic resurfacing model for Venus; the resurfacing controversy for Venus; and the deformation belts of Lavinia Planitia.

Transit of Venus 2004 [detail

NASA Image and Video Library

2017-12-08

To read more about the 2012 Venus Transit go to: sunearthday.nasa.gov/transitofvenus Add your photos of the Transit of Venus to our Flickr Group here: www.flickr.com/groups/venustransit/ NASA FILE PHOTO Date: 8 Jun 2004 NASA's TRACE satellite captured this image of Venus crossing the face of the Sun as seen from Earth orbit. The last event occurred in 1882. The next Venus transit will be visible in 2012. This image also is a good example of the scale of Earth to the Sun since Venus and Earth are similar in size. Credit: NASA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Little or no solar wind enters Venus' atmosphere at solar minimum.

PubMed

Zhang, T L; Delva, M; Baumjohann, W; Auster, H-U; Carr, C; Russell, C T; Barabash, S; Balikhin, M; Kudela, K; Berghofer, G; Biernat, H K; Lammer, H; Lichtenegger, H; Magnes, W; Nakamura, R; Schwingenschuh, K; Volwerk, M; Vörös, Z; Zambelli, W; Fornacon, K-H; Glassmeier, K-H; Richter, I; Balogh, A; Schwarzl, H; Pope, S A; Shi, J K; Wang, C; Motschmann, U; Lebreton, J-P

2007-11-29

Venus has no significant internal magnetic field, which allows the solar wind to interact directly with its atmosphere. A field is induced in this interaction, which partially shields the atmosphere, but we have no knowledge of how effective that shield is at solar minimum. (Our current knowledge of the solar wind interaction with Venus is derived from measurements at solar maximum.) The bow shock is close to the planet, meaning that it is possible that some solar wind could be absorbed by the atmosphere and contribute to the evolution of the atmosphere. Here we report magnetic field measurements from the Venus Express spacecraft in the plasma environment surrounding Venus. The bow shock under low solar activity conditions seems to be in the position that would be expected from a complete deflection by a magnetized ionosphere. Therefore little solar wind enters the Venus ionosphere even at solar minimum.

Average dimension and magnetic structure of the distant Venus magnetotail

NASA Technical Reports Server (NTRS)

Saunders, M. A.; Russell, C. T.

1986-01-01

The first major statistical investigation of the far wake of an unmagnetized object embedded in the solar wind is reported. The investigation is based on Pioneer Venus Orbiter magnetometer data from 70 crossings of the Venus wake at altitudes between 5 and 11 Venus radii during reasonably steady IMF conditions. It is found that Venus has a well-developed-tail, flaring with altitude and possibly broader in the direction parallel to the IMF cross-flow component. Tail lobe field polarities and the direction of the cross-tail field are consistent with tail accretion from the solar wind. Average values for the cross-tail field (2 nT) and the distant tail flux (3 MWb) indicate that most distant tail field lines close across the center of the tail and are not rooted in the Venus ionosphere. The findings are illustrated in a three-dimensional schematic.

The interior of Venus and Tectonic implications

NASA Technical Reports Server (NTRS)

Phillips, R. J.; Malin, M. C.

1983-01-01

It is noted in the present consideration of the Venus lithosphere and its implications for plate tectonics that the major linear elevated regions of Venus, which are associated with Beta Regio and Aphrodite Terra, do not seem to have the shape required for sure interpretation as the divergent plate boundaries of seafloor spreading. Such tectonics instead appear to be confined to the median plains, and may not be resolvable in the Pioneer Venus altimetry data. The ratios of gravity anomalies to topographic heights indicate that surface load compensation occurs at depths greater than about 100 km under the western Aphrodite Terra and 400 km under Beta Regio, with at least some of this compensation probably being maintained by mantle convection. It is also found that the shape of Venus's hypsogram is very different from the ocean mode of the earth's hypsogram, and it is proposed that Venus tectonics resemble intraplate, basin-and-swell tectonics on earth.

Global scale concentrations of volcanic activity on Venus: A summary of three 23rd Lunar and Planetary Science Conference abstracts. 1: Venus volcanism: Global distribution and classification from Magellan data. 2: A major global-scale concentration of volcanic activity in the Beta-Atla-Themis region of Venus. 3: Two global concentrations of volcanism on Venus: Geologic associations and implications for global pattern of upwelling and downwelling

NASA Technical Reports Server (NTRS)

Crumpler, L. S.; Aubele, Jayne C.; Head, James W.; Guest, J.; Saunders, R. S.

1992-01-01

As part of the analysis of data from the Magellan Mission, we have compiled a global survey of the location, dimensions, and subsidiary notes of all identified volcanic features on Venus. More than 90 percent of the surface area was examined and the final catalog comprehensively identifies 1548 individual volcanic features larger than approximately 20 km in diameter. Volcanic features included are large volcanoes, intermediate volcanoes, fields of small shield volcanoes, calderas, large lava channels, and lava floods as well as unusual features first noted on Venus such as coronae, arachnoids, and novae.

Single-Camera-Based Method for Step Length Symmetry Measurement in Unconstrained Elderly Home Monitoring.

PubMed

Cai, Xi; Han, Guang; Song, Xin; Wang, Jinkuan

2017-11-01

single-camera-based gait monitoring is unobtrusive, inexpensive, and easy-to-use to monitor daily gait of seniors in their homes. However, most studies require subjects to walk perpendicularly to camera's optical axis or along some specified routes, which limits its application in elderly home monitoring. To build unconstrained monitoring environments, we propose a method to measure step length symmetry ratio (a useful gait parameter representing gait symmetry without significant relationship with age) from unconstrained straight walking using a single camera, without strict restrictions on walking directions or routes. according to projective geometry theory, we first develop a calculation formula of step length ratio for the case of unconstrained straight-line walking. Then, to adapt to general cases, we propose to modify noncollinear footprints, and accordingly provide general procedure for step length ratio extraction from unconstrained straight walking. Our method achieves a mean absolute percentage error (MAPE) of 1.9547% for 15 subjects' normal and abnormal side-view gaits, and also obtains satisfactory MAPEs for non-side-view gaits (2.4026% for 45°-view gaits and 3.9721% for 30°-view gaits). The performance is much better than a well-established monocular gait measurement system suitable only for side-view gaits with a MAPE of 3.5538%. Independently of walking directions, our method can accurately estimate step length ratios from unconstrained straight walking. This demonstrates our method is applicable for elders' daily gait monitoring to provide valuable information for elderly health care, such as abnormal gait recognition, fall risk assessment, etc. single-camera-based gait monitoring is unobtrusive, inexpensive, and easy-to-use to monitor daily gait of seniors in their homes. However, most studies require subjects to walk perpendicularly to camera's optical axis or along some specified routes, which limits its application in elderly home monitoring. To build unconstrained monitoring environments, we propose a method to measure step length symmetry ratio (a useful gait parameter representing gait symmetry without significant relationship with age) from unconstrained straight walking using a single camera, without strict restrictions on walking directions or routes. according to projective geometry theory, we first develop a calculation formula of step length ratio for the case of unconstrained straight-line walking. Then, to adapt to general cases, we propose to modify noncollinear footprints, and accordingly provide general procedure for step length ratio extraction from unconstrained straight walking. Our method achieves a mean absolute percentage error (MAPE) of 1.9547% for 15 subjects' normal and abnormal side-view gaits, and also obtains satisfactory MAPEs for non-side-view gaits (2.4026% for 45°-view gaits and 3.9721% for 30°-view gaits). The performance is much better than a well-established monocular gait measurement system suitable only for side-view gaits with a MAPE of 3.5538%. Independently of walking directions, our method can accurately estimate step length ratios from unconstrained straight walking. This demonstrates our method is applicable for elders' daily gait monitoring to provide valuable information for elderly health care, such as abnormal gait recognition, fall risk assessment, etc.

Towards fish-eye camera based in-home activity assessment.

PubMed

Bas, Erhan; Erdogmus, Deniz; Ozertem, Umut; Pavel, Misha

2008-01-01

Indoors localization, activity classification, and behavioral modeling are increasingly important for surveillance applications including independent living and remote health monitoring. In this paper, we study the suitability of fish-eye cameras (high-resolution CCD sensors with very-wide-angle lenses) for the purpose of monitoring people in indoors environments. The results indicate that these sensors are very useful for automatic activity monitoring and people tracking. We identify practical and mathematical problems related to information extraction from these video sequences and identify future directions to solve these issues.

Laparoscopic female sterilisation by a single port through monitor--a better alternative.

PubMed

Sewta, Rajender Singh

2011-04-01

Female sterilisation by tubal occlusion method by laparocator is most widely used and accepted technique of all family planning measures all over the world. After the development of laparoscopic surgery in all faculties of surgery by monitor, now laparoscopic female sterilisation has been developed to do under monitor control by two ports--one for laparoscope and second for ring applicator. But the technique has been modified using single port with monitor through laparocator in which camera is fitted on the eye piece of laparocator (the same laparocator which is commonly used in camps without monitor since a long time in India). In this study over a period of about 2 years, a total 2011 cases were operated upon. In this study, I used camera and monitor through a single port by laparocator to visualise as well as to apply ring on fallopian tubes. The result is excellent and is a better alternative to conventional laparoscopic sterilisation and double puncture technique through camera--which give two scars and an extra assistant is required. However, there was no failure and the strain on surgeon's eye was minimum. Single port is much easier, safe, equally effective and better acceptable method.

Weather and atmosphere observation with the ATOM all-sky camera

NASA Astrophysics Data System (ADS)

Jankowsky, Felix; Wagner, Stefan

2015-03-01

The Automatic Telescope for Optical Monitoring (ATOM) for H.E.S.S. is an 75 cm optical telescope which operates fully automated. As there is no observer present during observation, an auxiliary all-sky camera serves as weather monitoring system. This device takes an all-sky image of the whole sky every three minutes. The gathered data then undergoes live-analysis by performing astrometric comparison with a theoretical night sky model, interpreting the absence of stars as cloud coverage. The sky monitor also serves as tool for a meteorological analysis of the observation site of the the upcoming Cherenkov Telescope Array. This overview covers design and benefits of the all-sky camera and additionally gives an introduction into current efforts to integrate the device into the atmosphere analysis programme of H.E.S.S.

Studying the Variability of Bright Stars with the CONCAM Sky Monitoring Network

NASA Astrophysics Data System (ADS)

Pereira, W. E.; Nemiroff, R. J.; Rafert, J. B.; Perez-Ramirez, D.

2001-12-01

CONCAMs have now been deployed at some of the world's major observatories including KPNO in Arizona, Mauna Kea in Hawaii, and Wise Observatory in Israel. Data from these mobile, inexpensive and continuous sky cameras, consisting of a fish-eye lens mated to a CCD camera and run by a laptop, has been ever-increasing. Initial efforts to carry out photometric analysis of CONCAM fits images have now been fortified by a more automated technique of analyzing this data. Results of such analyses - variability of several bright stars, in particular, are presented, as well as the use of these cameras as cloud monitors to remote observers.

The various contributions in Venus rotation rate and LOD

NASA Astrophysics Data System (ADS)

Cottereau, L.; Rambaux, N.; Lebonnois, S.; Souchay, J.

2011-07-01

Context. Thanks to the Venus Express Mission, new data on the properties of Venus could be obtained, in particular concerning its rotation. Aims: In view of these upcoming results, the purpose of this paper is to determine and compare the major physical processes influencing the rotation of Venus and, more particularly, the angular rotation rate. Methods: Applying models already used for Earth, the effect of the triaxiality of a rigid Venus on its period of rotation are computed. Then the variations of Venus rotation caused by the elasticity, the atmosphere, and the core of the planet are evaluated. Results: Although the largest irregularities in the rotation rate of the Earth on short time scales are caused by its atmosphere and elastic deformations, we show that the irregularities for Venus are dominated by the tidal torque exerted by the Sun on its solid body. Indeed, as Venus has a slow rotation, these effects have a large amplitude of two minutes of time (mn). These variations in the rotation rate are greater than the one induced by atmospheric wind variations that can reach 25-50 s of time (s), depending on the simulation used. The variations due to the core effects that vary with its size between 3 and 20 s are smaller. Compared to these effects, the influence of the elastic deformation caused by the zonal tidal potential is negligible. Conclusions: As the variations in the rotation of Venus reported here are close to 3 mn peak to peak, they should influence past, present, and future observations, thereby providing further constraints on the planet's internal structure and atmosphere.

Long-Lived Venus Lander Conceptual Design: How To Keep It Cool

NASA Technical Reports Server (NTRS)

Dyson, Ridger W.; Schmitz, Paul C.; Penswick, L. Barry; Bruder, Geoffrey A.

2009-01-01

Surprisingly little is known about Venus, our neighboring sister planet in the solar system, due to the challenges of operating in its extremely hot, corrosive, and dense environment. For example, after over two dozen missions to the planet, the longest-lived lander was the Soviet Venera 13, and it only survived two hours on the surface. Several conceptual Venus mission studies have been formulated in the past two decades proposing lander architectures that potentially extend lander lifetime. Most recently, the Venus Science and Technology Definition Team (STDT) was commissioned by NASA to study a Venus Flagship Mission potentially launching in the 2020- 2025 time-frame; the reference lander of this study is designed to survive for only a few hours more than Venera 13 launched back in 1981! Since Cytherean mission planners lack a viable approach to a long-lived surface architecture, specific scientific objectives outlined in the National Science Foundation Decadal Survey and Venus Exploration Advisory Group final report cannot be completed. These include: mapping the mineralogy and composition of the surface on a planetary scale determining the age of various rock samples on Venus, searching for evidence of changes in interior dynamics (seismometry) and its impact on climate and many other key observations that benefit with time scales of at least a full Venus day (Le. daylight/night cycle). This report reviews those studies and recommends a hybrid lander architecture that can survive for at least one Venus day (243 Earth days) by incorporating selective Stirling multi-stage active cooling and hybrid thermoacoustic power.

Venusians: the Planet Venus in the 18th-Century Extraterrestrial Life Debate

NASA Astrophysics Data System (ADS)

Duner, David

2013-05-01

In the seventeenth and eighteenth centuries it became possible to believe in the existence of life on other planets on scientific grounds. Once the Earth was no longer the center of the universe according to Copernicus, once Galileo had aimed his telescope at the Moon and found it a rough globe with mountains and seas, the assumption of life on other planets became much less far-fetched. In general there were no actual differences between Earth and Venus, since both planets orbited the Sun, were of similar size, and possessed mountains and an atmosphere. If there is life on Earth, one may ponder why it could not also exist on Venus. In the extraterrestrial life debate of the seventeenth and eighteenth centuries, the Moon, our closest celestial body, was the prime candidate for life on other worlds, although a number of scientists and scholars also speculated about life on Venus and on other planets, both within our solar system and beyond its frontiers. This chapter discusses the arguments for life on Venus and those scientific findings that were used to support them, which were based in particular on assumptions and claims that both mountains and an atmosphere had been found on Venus. The transits of Venus in the 1760s became especially important for the notion that life could thrive on Venus. Here, I detect two significant cognitive processes that were at work in the search for life on Venus, i.e., analogical reasoning and epistemic perception, while analogies and interpretations of sensory impressions based on prior knowledge played an important role in astrobiological theories.

The Creation of a Beneficial Bioshpere from Co2 in the Clouds of Venus

NASA Astrophysics Data System (ADS)

Linaraki, D. L.; Oungrinis, K. A.

2017-02-01

This research resulted in an architectural design for a Venus colony based on multiple factors combination, such as psychology of space, predicted near-future technology, and the identified environmental conditions on Venus.

Venus - Three-Dimensional Perspective View of Alpha Region

NASA Image and Video Library

1996-12-02

A portion of Alpha Regio is displayed in this three-dimensional perspective view of the surface of Venus from NASA Magellan spacecraft. In 1963, Alpha Regio was the first feature on Venus to be identified from Earth-based radar.

Solar Wind Interaction and Impact on the Venus Atmosphere

NASA Astrophysics Data System (ADS)

Futaana, Yoshifumi; Stenberg Wieser, Gabriella; Barabash, Stas; Luhmann, Janet G.

2017-11-01

Venus has intrigued planetary scientists for decades because of its huge contrasts to Earth, in spite of its nickname of "Earth's Twin". Its invisible upper atmosphere and space environment are also part of the larger story of Venus and its evolution. In 60s to 70s, several missions (Venera and Mariner series) explored Venus-solar wind interaction regions. They identified the basic structure of the near-Venus space environment, for example, existence of the bow shock, magnetotail, ionosphere, as well as the lack of the intrinsic magnetic field. A huge leap in knowledge about the solar wind interaction with Venus was made possible by the 14-year long mission, Pioneer Venus Orbiter (PVO), launched in 1978. More recently, ESA's probe, Venus Express (VEX), was inserted into orbit in 2006, operated for 8 years. Owing to its different orbit from that of PVO, VEX made unique measurements in the polar and terminator regions, and probed the near-Venus tail for the first time. The near-tail hosts dynamic processes that lead to plasma energization. These processes in turn lead to the loss of ionospheric ions to space, slowly eroding the Venusian atmosphere. VEX carried an ion spectrometer with a moderate mass-separation capability and the observed ratio of the escaping hydrogen and oxygen ions in the wake indicates the stoichiometric loss of water from Venus. The structure and dynamics of the induced magnetosphere depends on the prevailing solar wind conditions. VEX studied the response of the magnetospheric system on different time scales. A plethora of waves was identified by the magnetometer on VEX; some of them were not previously observed by PVO. Proton cyclotron waves were seen far upstream of the bow shock, mirror mode waves were observed in magnetosheath and whistler mode waves, possibly generated by lightning discharges were frequently seen. VEX also encouraged renewed numerical modeling efforts, including fluid-type of models and particle-fluid hybrid type of models, describing the plasma interaction on scales ranging from ion gyro radius to the entire induced magnetosphere. In this review article, we review what has been found from space physics measurements around Venus (from the solar wind down to the ionopause), with a particular emphasis on updated results since the Venus Express mission. We conclude the article by a short discussion on the remaining open scientific questions and the future of this field.

The Effect of Bond Albedo on Venus' Atmospheric and Surface Temperatures

NASA Astrophysics Data System (ADS)

Bullock, M. A.; Limaye, S. S.; Grinspoon, D. H.; Way, M.

2017-12-01

In spite of Venus' high planetary albedo, sufficient solar energy reaches the surface to drive a powerful greenhouse effect. The surface temperature is three times higher than it would be without an atmosphere. However, the details of the energy balance within Venus' atmosphere are poorly understood. Half of the solar energy absorbed within the clouds, where most of the solar energy is absorbed, is due to an unknown agent. One of the challenges of modeling Venus' atmosphere has been to account for all the sources of opacity sufficient to generate a globally averaged surface temperature of 735 K, when only 2% of the incoming solar energy is deposited at the surface. The wavelength and spherically integrated albedo, or Bond albedo, has typically been cited as between 0.7 and 0.82 (Colin 1983). Yet, recent photometry of Venus at extended phase angles between 2 and 179° indicate a Bond albedo of 0.90 (Mallama et al., 2006). The authors note an increase in cloud top brightness at phase angles < 2°, which effectively increases the spherically integrated albedo. They suggest that forward scattering by the H2SO4/H2O aerosols of the upper cloud is responsible for Venus' high albedo at very low phase angles. The present work investigates the implications of such a high albedo for understanding and modeling the energy balance of Venus' atmosphere. Using the successful 1D radiative transfer model SimVenus that incorporates the opacity due to 9 major gases in Venus' atmosphere, as well as multiple scattering calculations of radiation within the clouds, the sensitivity of surface temperature was studied as a function of Bond albedo. Results of these model calculations are shown in Fig. 1. Figure 1a (left). Venus' atmospheric temperature profile for different values of Bond albedo. The structure and radiative effects of the clouds are fixed. Figure 1b (right). Venus surface temperature as Bond Albedo changes. Radiative-convective equilibrium models predict the correct globally averaged surface temperature at a=0.81. Calculations here show that a Bond albedo of a=0.9 would yield a surface temperature of 666.4 K, about 70 K too low, unless there is additional thermal absorption within the atmosphere that is not understood. Colin, L.,, Venus, University of Arizona Press, Tucson, 1983, pp 10-26. Mallama, A., et al., 2006. Icarus. 182, 10-22.

Multi-camera synchronization core implemented on USB3 based FPGA platform

NASA Astrophysics Data System (ADS)

Sousa, Ricardo M.; Wäny, Martin; Santos, Pedro; Dias, Morgado

2015-03-01

Centered on Awaiba's NanEye CMOS image sensor family and a FPGA platform with USB3 interface, the aim of this paper is to demonstrate a new technique to synchronize up to 8 individual self-timed cameras with minimal error. Small form factor self-timed camera modules of 1 mm x 1 mm or smaller do not normally allow external synchronization. However, for stereo vision or 3D reconstruction with multiple cameras as well as for applications requiring pulsed illumination it is required to synchronize multiple cameras. In this work, the challenge of synchronizing multiple selftimed cameras with only 4 wire interface has been solved by adaptively regulating the power supply for each of the cameras. To that effect, a control core was created to constantly monitor the operating frequency of each camera by measuring the line period in each frame based on a well-defined sampling signal. The frequency is adjusted by varying the voltage level applied to the sensor based on the error between the measured line period and the desired line period. To ensure phase synchronization between frames, a Master-Slave interface was implemented. A single camera is defined as the Master, with its operating frequency being controlled directly through a PC based interface. The remaining cameras are setup in Slave mode and are interfaced directly with the Master camera control module. This enables the remaining cameras to monitor its line and frame period and adjust their own to achieve phase and frequency synchronization. The result of this work will allow the implementation of smaller than 3mm diameter 3D stereo vision equipment in medical endoscopic context, such as endoscopic surgical robotic or micro invasive surgery.

Image synchronization for 3D application using the NanEye sensor

NASA Astrophysics Data System (ADS)

Sousa, Ricardo M.; Wäny, Martin; Santos, Pedro; Dias, Morgado

2015-03-01

Based on Awaiba's NanEye CMOS image sensor family and a FPGA platform with USB3 interface, the aim of this paper is to demonstrate a novel technique to perfectly synchronize up to 8 individual self-timed cameras. Minimal form factor self-timed camera modules of 1 mm x 1 mm or smaller do not generally allow external synchronization. However, for stereo vision or 3D reconstruction with multiple cameras as well as for applications requiring pulsed illumination it is required to synchronize multiple cameras. In this work, the challenge to synchronize multiple self-timed cameras with only 4 wire interface has been solved by adaptively regulating the power supply for each of the cameras to synchronize their frame rate and frame phase. To that effect, a control core was created to constantly monitor the operating frequency of each camera by measuring the line period in each frame based on a well-defined sampling signal. The frequency is adjusted by varying the voltage level applied to the sensor based on the error between the measured line period and the desired line period. To ensure phase synchronization between frames of multiple cameras, a Master-Slave interface was implemented. A single camera is defined as the Master entity, with its operating frequency being controlled directly through a PC based interface. The remaining cameras are setup in Slave mode and are interfaced directly with the Master camera control module. This enables the remaining cameras to monitor its line and frame period and adjust their own to achieve phase and frequency synchronization. The result of this work will allow the realization of smaller than 3mm diameter 3D stereo vision equipment in medical endoscopic context, such as endoscopic surgical robotic or micro invasive surgery.

Design optimisation of a TOF-based collimated camera prototype for online hadrontherapy monitoring

NASA Astrophysics Data System (ADS)

Pinto, M.; Dauvergne, D.; Freud, N.; Krimmer, J.; Letang, J. M.; Ray, C.; Roellinghoff, F.; Testa, E.

2014-12-01

Hadrontherapy is an innovative radiation therapy modality for which one of the main key advantages is the target conformality allowed by the physical properties of ion species. However, in order to maximise the exploitation of its potentialities, online monitoring is required in order to assert the treatment quality, namely monitoring devices relying on the detection of secondary radiations. Herein is presented a method based on Monte Carlo simulations to optimise a multi-slit collimated camera employing time-of-flight selection of prompt-gamma rays to be used in a clinical scenario. In addition, an analytical tool is developed based on the Monte Carlo data to predict the expected precision for a given geometrical configuration. Such a method follows the clinical workflow requirements to simultaneously have a solution that is relatively accurate and fast. Two different camera designs are proposed, considering different endpoints based on the trade-off between camera detection efficiency and spatial resolution to be used in a proton therapy treatment with active dose delivery and assuming a homogeneous target.

Mariner Venus Mercury, 1973. [close flyby investigation of mercury after Venus-flyby, and observation of Kohoutek comet

NASA Technical Reports Server (NTRS)

Wilson, J. H.

1973-01-01

The Mariner Venus Mercury 1973 unmanned mission is discussed, which is designed to conduct a close flyby investigation of the planet Mercury after using the gravity-turn technique in a Venus flyby. Its scientific purposes include photographic, thermal, and spectral surveys, radio occulation, and charged particle/magnetic measurements at each planet, observation of solar-system fields and particles from 1.0 a.u. down to 0.4 a.u., and comparative planetary surveys between the Earth, the Moon, Venus, and Mercury. It is also intended to observe Kohoutek's comet. The trajectory permits establishment of a solar orbit in phase with Mercury's, permitting repeated encounters with that planet.

Viscous relaxation of impact crater relief on Venus - Constraints on crustal thickness and thermal gradient

NASA Technical Reports Server (NTRS)

Grimm, Robert E.; Solomon, Sean C.

1988-01-01

Models for the viscous relaxation of impact crater topography are used to constrain the crustal thickness (H) and the mean lithospheric thermal gradient beneath the craters on Venus. A general formulation for gravity-driven flow in a linearly viscous fluid has been obtained which incorporates the densities and temperature-dependent effective viscosities of distinct crust and mantle layers. An upper limit to the crustal volume of Venus of 10 to the 10th cu km is obtained which implies either that the average rate of crustal generation has been much smaller on Venus than on earth or that some form of crustal recycling has occurred on Venus.

The thermosphere and ionosphere of Venus

NASA Technical Reports Server (NTRS)

Cravens, T. E.

1992-01-01

Our knowledge of the upper atmosphere and ionosphere of Venus and its interaction with the solar wind has advanced dramatically over the last decade, largely due to the data obtained during the Pioneer Venus mission and to the theoretical work that was motivated by this data. Most of this information was obtained during the period 1978 through 1981, when the periapsis of the Pioneer Venus Orbiter (PVO) was still in the measurable atmosphere. However, solar gravitational perturbations will again lower the PVO periapsis into the upper atmosphere in September 1992, prior to the destruction of the spacecraft toward the end of this year. The physics and chemistry of the thermosphere and ionosphere of Venus are reviewed.

Rheology, tectonics, and the structure of the Venus lithosphere

NASA Technical Reports Server (NTRS)

Zuber, M. T.

1994-01-01

Given the absence of ground truth information on seismic structure, heat flow, and rock strength, or short wavelength gravity or magnetic data for Venus, information on the thermal, mechanical and compositional nature of the shallow interior must be obtained by indirect methods. Using pre-Magellan data, theoretical models constrained by the depths of impact craters and the length scales of tectonic features yielded estimates on the thickness of Venus' brittle-elastic lithosphere and the allowable range of crustal thickness and surface thermal gradient. The purpose of this study is to revisit the question of the shallow structure of Venus based on Magellan observations of the surface and recent experiments that address Venus' crustal rheology.

The Atmosphere and Climate of Venus

NASA Astrophysics Data System (ADS)

Bullock, M. A.; Grinspoon, D. H.

Venus lies just sunward of the inner edge of the Sun's habitable zone. Liquid water is not stable. Like Earth and Mars, Venus probably accreted at least an ocean's worth of water, although there are alternative scenarios. The loss of this water led to the massive, dry CO2 atmosphere, extensive H2SO4 clouds (at least some of the time), and an intense CO2 greenhouse effect. This chapter describes the current understanding of Venus' atmosphere, established from the data of dozens of spacecraft and atmospheric probe missions since 1962, and by telescopic observations since the nineteenth century. Theoretical work to model the temperature, chemistry, and circulation of Venus' atmosphere is largely based on analogous models developed in the Earth sciences. We discuss the data and modeling used to understand the temperature structure of the atmosphere, as well as its composition, cloud structure, and general circulation. We address what is known and theorized about the origin and early evolution of Venus' atmosphere. It is widely understood that Venus' dense CO2 atmosphere is the ultimate result of the loss of an ocean to space, but the timing of major transitions in Venus' climate is very poorly constrained by the available data. At present, the bright clouds allow only 20% of the sunlight to drive the energy balance and therefore determine conditions at Venus' surface. Like Earth and Mars, differential heating between the equator and poles drives the atmospheric circulation. Condensable species in the atmosphere create clouds and hazes that drive feedbacks that alter radiative forcing. Also in common with Earth and Mars, the loss of light, volatile elements to space produces long-term changes in composition and chemistry. As on Earth, geologic processes are most likely modifying the atmosphere and clouds by injecting gases from volcanos as well as directly through chemical reactions with the surface. The sensitivity of Venus' atmospheric energy balance is quantified in this chapter in terms of the initial forcing due to a perturbation, radiative response, and indirect responses, which are feedbacks — either positive or negative. When applied to one Venus climate model, we found that the albedo-radiative feedback is more important than greenhouse forcing for small changes in atmospheric H2O and SO2. An increase in these gases cools the planet by making the clouds brighter. On geologic timescales the reaction of some atmospheric species (SO2, CO, OCS, S, H2O, H2S, HCl, HF) with surface minerals could cause significant changes in atmospheric composition. Laboratory data and thermochemical modeling have been important for showing that atmospheric SO2 would be depleted in ~10 m.y. if carbonates are available at the surface. Without replenishment, the clouds would disappear. Alternatively, the oxidation of pyrite could add SO2 to the atmosphere while producing stable Fe oxides at the surface. The correlation of near-infrared high emissivity (dark) surface features with three young, large volcanos on Venus is strong evidence for recent volcanic activity at these sites, certainly over the timescale necessary to support the clouds. We address the nature of heterogeneous reactions with the surface and the implications for climate change on Venus. Chemical and mineralogical signatures of past climates must exist at the surface and below, so in situ experiments on the composition of surface layers are vital for reconstructing Venus' past climate. Many of the most Earth-like planets found around other stars will probably resemble Venus or a younger version of Venus. We finish the chapter with discussing what Venus can tell us about life in the universe, since it is an example of a planetary climate rendered uninhabitable. It also resembles our world's likely future. As with the climate history of Venus, however, the timing of predictable climate transitions on the Earth is poorly constrained by the data.

Adjustable control station with movable monitors and cameras for viewing systems in robotics and teleoperations

NASA Technical Reports Server (NTRS)

Diner, Daniel B. (Inventor)

1994-01-01

Real-time video presentations are provided in the field of operator-supervised automation and teleoperation, particularly in control stations having movable cameras for optimal viewing of a region of interest in robotics and teleoperations for performing different types of tasks. Movable monitors to match the corresponding camera orientations (pan, tilt, and roll) are provided in order to match the coordinate systems of all the monitors to the operator internal coordinate system. Automated control of the arrangement of cameras and monitors, and of the configuration of system parameters, is provided for optimal viewing and performance of each type of task for each operator since operators have different individual characteristics. The optimal viewing arrangement and system parameter configuration is determined and stored for each operator in performing each of many types of tasks in order to aid the automation of setting up optimal arrangements and configurations for successive tasks in real time. Factors in determining what is optimal include the operator's ability to use hand-controllers for each type of task. Robot joint locations, forces and torques are used, as well as the operator's identity, to identify the current type of task being performed in order to call up a stored optimal viewing arrangement and system parameter configuration.

A semi-automated method of monitoring dam passage of American Eels Anguilla rostrata

USGS Publications Warehouse

Welsh, Stuart A.; Aldinger, Joni L.

2014-01-01

Fish passage facilities at dams have become an important focus of fishery management in riverine systems. Given the personnel and travel costs associated with physical monitoring programs, automated or semi-automated systems are an attractive alternative for monitoring fish passage facilities. We designed and tested a semi-automated system for eel ladder monitoring at Millville Dam on the lower Shenandoah River, West Virginia. A motion-activated eel ladder camera (ELC) photographed each yellow-phase American Eel Anguilla rostrata that passed through the ladder. Digital images (with date and time stamps) of American Eels allowed for total daily counts and measurements of eel TL using photogrammetric methods with digital imaging software. We compared physical counts of American Eels with camera-based counts; TLs obtained with a measuring board were compared with TLs derived from photogrammetric methods. Data from the ELC were consistent with data obtained by physical methods, thus supporting the semi-automated camera system as a viable option for monitoring American Eel passage. Time stamps on digital images allowed for the documentation of eel passage time—data that were not obtainable from physical monitoring efforts. The ELC has application to eel ladder facilities but can also be used to monitor dam passage of other taxa, such as crayfishes, lampreys, and water snakes.

MEETING VENUS. A Collection of Papers presented at the Venus Transit Conference Tromsoe 2012

NASA Astrophysics Data System (ADS)

Sterken, Christiaan; Aspaas, Per Pippin

2013-05-01

On 2-3 June 2012, the University of Tromsoe hosted a conference about the cultural and scientific history of the transits of Venus. The conference took place in Tromsoe for two very specific reasons. First and foremost, the last transit of Venus of this century lent itself to be observed on the disc of the Midnight Sun in this part of Europe during the night of 5 to 6 June 2012. Second, several Venus transit expeditions in this region were central in the global enterprise of measuring the scale of the solar system in the eighteenth century. The site of the conference was the Nordnorsk Vitensenter (Science Centre of Northern Norway), which is located at the campus of the University of Tromsoe. After the conference, participants were invited to either stay in Tromsoe until the midnight of 5-6 June, or take part in a Venus transit voyage in Finnmark, during which the historical sites Vardoe, Hammerfest, and the North Cape were to be visited. The post-conference program culminated with the participants observing the transit of Venus in or near Tromsoe, Vardoe and even from a plane near Alta. These Proceedings contain a selection of the lectures delivered on 2-3 June 2012, and also a narrative description of the transit viewing from Tromsoe, Vardoe and Alta. The title of the book, Meeting Venus, refers the title of a play by the Hungarian film director, screenwriter and opera director Istvan Szabo (1938-). The autobiographical movie Meeting Venus (1991) directed by him is based on his experience directing Tannhauser at the Paris Opera in 1984. The movie brings the story of an imaginary international opera company that encounters a never ending series of difficulties and pitfalls that symbolise the challenges of any multicultural and international endeavour. As is evident from the many papers presented in this book, Meeting Venus not only contains the epic tales of the transits of the seventeenth, eighteenth and nineteenth centuries, it also covers the conference participants' encounter with "Venus on the Sun" in historical archives as well as face-to-face at several locations in the Troms and Finnmark counties.

Venus Atmospheric Maneuverable Platform (VAMP)

NASA Astrophysics Data System (ADS)

Griffin, K.; Sokol, D.; Lee, G.; Dailey, D.; Polidan, R.

2013-12-01

We have explored a possible new approach to Venus upper atmosphere exploration by applying recent Northrop Grumman (non-NASA) development programs to the challenges associated with Venus upper atmosphere science missions. Our concept is a low ballistic coefficient (<50 Pa), semi-buoyant aircraft that deploys prior to entering the Venus atmosphere, enters the Venus atmosphere without an aeroshell, and provides a long-lived (months to years), maneuverable vehicle capable of carrying science payloads to explore the Venus upper atmosphere. In 2012 we initiated a feasibility study for a semi-buoyant maneuverable vehicle that could operate in the upper atmosphere of Venus. In this presentation we report results from the ongoing study and plans for future analyses and prototyping to advance and refine the concept. We will discuss the overall mission architecture and concept of operations from launch through Venus arrival, orbit, entry, and atmospheric science operations. We will present a strawman concept of VAMP, including ballistic coefficient, planform area, percent buoyancy, inflation gas, wing span, vehicle mass, power supply, propulsion, materials considerations, structural elements, subsystems, and packaging. The interaction between the VAMP vehicle and the supporting orbiter will also be discussed. In this context, we will specifically focus upon four key factors impacting the design and performance of VAMP: 1. Feasibility of and options for the deployment of the vehicle in space 2. Entry into the Venus atmosphere, including descent profile, heat rate, total heat load, stagnation temperature, control, and entry into level flight 3. Characteristics of flight operations and performance in the Venus atmosphere: altitude range, latitude and longitude access, day/night performance, aircraft performance (aerodynamics, power required vs. power available, propulsion, speed, percent buoyancy), performance sensitivity to payload weight 4. Science payload accommodation, constraints, and opportunities We will discuss interdependencies of the above factors and the manner in which the VAMP strawman's characteristics affect the CONOPs and the science objectives. We will show how the these factors provide constraints as well as enable opportunities for novel long duration scientific studies of the Venus upper atmosphere that support VEXAG goals 2 and 3. We will also discuss how the VAMP platform itself can facilitate some of these science measurements.

Venus Atmospheric Maneuverable Platform (VAMP)

NASA Astrophysics Data System (ADS)

Polidan, R.; Lee, G.; Sokol, D.; Griffin, K.; Bolisay, L.; Barnes, N.

2014-04-01

Over the past years we have explored a possible new approach to Venus upper atmosphere exploration by applying recent Northrop Grumman (non-NASA) development programs to the challenges associated with Venus upper atmosphere science missions. Our concept is a low ballistic coefficient (<50 Pa), semibuoyant aircraft that deploys prior to entering the Venus atmosphere, enters the Venus atmosphere without an aeroshell, and provides a long-lived (months to years), maneuverable vehicle capable of carrying science payloads to explore the Venus upper atmosphere. VAMP targets the global Venus atmosphere between 55 and 70 km altitude and would be a platform to address VEXAG goals I.A, I.B, and I.C. We will discuss the overall mission architecture and concept of operations from launch through Venus arrival, orbit, entry, and atmospheric science operations. We will present a strawman concept of VAMP, including ballistic coefficient, planform area, percent buoyancy, inflation gas, wing span, vehicle mass, power supply, propulsion, materials considerations, structural elements, subsystems, and packaging. The interaction between the VAMP vehicle and the supporting orbiter will also be discussed. In this context, we will specifically focus upon four key factors impacting the design and performance of VAMP: 1. Science payload accommodation, constraints, and opportunities 2. Characteristics of flight operations and performance in the Venus atmosphere: altitude range, latitude and longitude access, day/night performance, aircraft performance, performance sensitivity to payload weight 3. Feasibility of and options for the deployment of the vehicle in space 4. Entry into the Venus atmosphere, including descent profile, heat rate, total heat load, stagnation temperature, control, and entry into level flight We will discuss interdependencies of the above factors and the manner in which the VAMP strawman's characteristics affect the CONOPs and the science objectives. We will show how the these factors provide constraints as well as enable opportunities for novel long duration scientific studies of the Venus upper atmosphere that support VEXAG goals I.A, I.B, and I.C.. We will also discuss how the VAMP platform itself can facilitate some of these science measurements.

Unlocking the secrets of Venus surface mineralogy from orbit

NASA Astrophysics Data System (ADS)

Helbert, J.; Maturilli, A.; Ferrari, S.; Dyar, M. D.; Mueller, N. T.; Smrekar, S. E.; Koulen, J.

2016-12-01

The surface composition of a planet is a key to understand its interior and evolution. Proper interpretations of Venus surface observations in the near-infrared require a dedicated laboratory effort. The atmosphere of Venus dictates which spectral bands on the surface can be observed. This places severe constraints on the ability to identify rock-forming minerals. To complicate matters further, we cannot observe reflectance, as would be the standard at 1 mm. Observations are obtained on the night side where the thermal emission of the surface is measured directly. Finally, high surface temperatures are known to affect band positions of mineral spectra as expected from crystal field theory. Over the last year we have started at the Planetary Spectroscopy Laboratory (PSL) at DLR in Berlin, Germany to systematically build a spectral library for rocks and minerals under Venus thermal conditions. Using funding from the European Union as part of the EuroPlanet consortium we extended the spectral coverage for high temperature measurements down to 0.7 micron. The spectral library will be key in understanding and modeling differences in emissivity between ambient and Venus conditions, potentially enabling calibration transfer between datasets. We can show that the expected emissivity variation between felsic and mafic minerals would be observable even with the limited number of surface windows available. Furthermore the absolute emissivity derived from our laboratory measurements at Venus temperature match in situ reflectivity data from the Venera 9 and 10 landing sites in the same bands. Based on experience gained from using the VIRTIS instrument on Venus Express to observe the surface of Venus and the new high temperature laboratory experiments, we have developed the multi-spectral Venus Emissivity Mapper (VEM) to study the surface of Venus. VEM imposes minimal requirements on the spacecraft and mission design and can therefore be added to any future Venus mission. Ideally, the VEM instrument will be combined with a high-resolution radar mapper to provide accurate topographic information, as it will be the case for the proposed NASA Discovery VERITAS mission or the ESA EnVision M5 proposal.

Exploring Venus Interior Structure by Detection of Infrasonic Waves

NASA Astrophysics Data System (ADS)

Mimoun, D.; Cutts, J.; Stevenson, D.; Garcia, R. F.

2015-04-01

Knowledge of the interior structure of Venus is currently impeded by the limited time that a seismometer can survive in the atmosphere of Venus. We propose to remotely detect quakes by infrasonic measurements at the top of the cloud layer.

Closing a Venus Flytrap with electrical and mid-IR photon stimulations

NASA Astrophysics Data System (ADS)

Eisen, David; Janssen, Douglas; Chen, Xing; Choa, Fow-Sen; Kostov, Dan; Fan, Jenyu

2013-03-01

Plants have mechanisms to perceive and transmit information between its organs and tissues. These signals had long been considered as hormonal or hydraulic in nature, but recent studies have shown that electrical signals are also produced causing physiological responses. In this work we show that Venus Flytrap, Dionaea muscipula, can respond to both electrical and optical signals beside mechanical stimulations. While the Venus Flytrap does not have any neurons, it does contain transport cells with very similar characteristics to neurotransmitters and uses ionic mechanisms, as human neurons do, to generate action potentials. In our electrical stimulation study, electrodes made out of soft cloth were soaked in salt water before being placed to the midrib (+) and lobe (-). The flytrap's surface resistance was determined by subtracting out the average electrode resistance from the measured electrode to plant surface resistance, yielding an average contact resistance of around 0.98MΩ. A logarithmic amplifier was used to monitor mechanically generated electrical signals. Two electrical pulses were generated by mechanically touching the trigger hairs in the lobe twice within 20 seconds. By discharging around 600μC charge stored in a capacitor we demonstrated electrically closing of the flytrap. For optical excitation we found in our FTIR study it's tissue contains very similar protein absorption peaks to that of insects. A 7.35μm laser with 50mw power was then used for the stimulation study. Electrical action potential was generated twice by mid-infrared photons before closure of the flytrap.

JPL's role in the SETI program

NASA Technical Reports Server (NTRS)

Klein, M. J.

1986-01-01

The goal of the JPL SETI Team is to develop the strategies and the instrumentation required to carry out an effective, yet affordable, SETI Microwave Observing Program. The primary responsibility for JPL is the development and implementation of the Sky Survey component of the bimodal search program recommended by the SETI Science Working Group (NASA Technical Paper 2244, 1983). JPL is also responsible for the design and implementation of microwave analog instrumentation (including antenna feed systems, low noise RF amplifiers, antenna monitor and control interfaces, etc.) to cover the microwave window for the Sky Survey and the Target Search observations. The primary site for the current SETI Field Test activity is the Venus Station of the Goldstone Deep Space Communication Complex. A SETI controller was constructed and installed so that pre-programmed and real time SETI monitor and control data can be sent to and from the station controller. This unit will be interfaced with the MCSA. A SETI Hardware Handbook was prepared to describe the various systems that will be used by the project at the Venus Station; the handbook is frequently being expanded and updated. The 65,000 channel FFT Spectrum analyzer in the RFI Surveillance System was modified to permit operation with variable resolutions (300 Hz to less than 1 Hz) and with real-time accumulation, which will enhance the capability of the system for testing Sky Survey search strategies and signal detection algorithms.

Zephyr: A Landsailing Rover for Venus

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A.; Oleson, Steven R.; Grantier, David

2014-01-01

With an average temperature of 450C and a corrosive atmosphere at a pressure of 90 bars, the surface of Venus is the most hostile environment of any planetary surface in the solar system. Exploring the surface of Venus would be an exciting goal, since Venus is a planet with significant scientific mysteries, and interesting geology and geophysics. Technology to operate at the environmental conditions of Venus is under development. A rover on the surface of Venus with capability comparable to the rovers that have been sent to Mars would push the limits of technology in high-temperature electronics, robotics, and robust systems. Such a rover would require the ability to traverse the landscape on extremely low power levels. We have analyzed an innovative concept for a planetary rover: a sail-propelled rover to explore the surface of Venus. Such a rover can be implemented with only two moving parts; the sail, and the steering. Although the surface wind speeds are low (under 1 m/s), at Venus atmospheric density even low wind speeds develop significant force. Under funding by the NASA Innovative Advanced Concepts office, a conceptual design for such a rover has been done. Total landed mass of the system is 265 kg, somewhat less than that of the MER rovers, with a 12 square meter rigid sail. The rover folds into a 3.6 meter aeroshell for entry into the Venus atmosphere and subsequent parachute landing on the surface. Conceptual designs for a set of hightemperature scientific instruments and a UHF communication system were done. The mission design lifetime is 50 days, allowing operation during the sunlit portion of one Venus day. Although some technology development is needed to bring the high-temperature electronics to operational readiness, the study showed that such a mobility approach is feasible, and no major difficulties are seen.

Scientific Balloons for Venus Exploration

NASA Astrophysics Data System (ADS)

Cutts, James; Yavrouian, Andre; Nott, Julian; Baines, Kevin; Limaye, Sanjay; Wilson, Colin; Kerzhanovich, Viktor; Voss, Paul; Hall, Jeffery

Almost 30 years ago, two balloons were successfully deployed into the atmosphere of Venus as an element of the VeGa - Venus Halley mission conducted by the Soviet Union. As interest in further Venus exploration grows among the established planetary exploration agencies - in Europe, Japan, Russia and the United States, use of balloons is emerging as an essential part of that investigative program. Venus balloons have been proposed in NASA’s Discovery program and ESA’s cosmic vision program and are a key element in NASA’s strategic plan for Venus exploration. At JPL, the focus for the last decade has been on the development of a 7m diameter superpressure pressure(twice that of VeGa) capable of carrying a 100 kg payload (14 times that of VeGA balloons), operating for more than 30 days (15 times the 2 day flight duration of the VeGa balloons) and transmitting up to 20 Mbit of data (300 times that of VeGa balloons). This new generation of balloons must tolerate day night transitions on Venus as well as extended exposure to the sulfuric acid environment. These constant altitude balloons operating at an altitude of about 55 km on Venus where temperatures are benign can also deploy sondes to sound the atmosphere beneath the probe and deliver deep sondes equipped to survive and operate down to the surface. The technology for these balloons is now maturing rapidly and we are now looking forward to the prospects for altitude control balloons that can cycle repeatedly through the Venus cloud region. One concept, which has been used for tropospheric profiling in Antarctica, is the pumped-helium balloon, with heritage to the anchor balloon, and would be best adapted for flight above the 55 km level. Phase change balloons, which use the atmosphere as a heat engine, can be used to investigate the lower cloud region down to 30 km. Progress in components for high temperature operation may also enable investigation of the deep atmosphere of Venus with metal-based balloons.

Venus Atmospheric Maneuverable Platform (VAMP) - A Low Cost Venus Exploration Concept

NASA Astrophysics Data System (ADS)

Lee, G.; Polidan, R. S.; Ross, F.

2015-12-01

The Northrop Grumman Aerospace Systems and L-Garde team has been developing an innovative mission concept: a long-lived, maneuverable platform to explore the Venus upper atmosphere. This capability is an implementation of our Lifting Entry Atmospheric Flight (LEAF) system concept, and the Venus implementation is called the Venus Atmospheric Maneuverable Platform (VAMP). The VAMP concept utilizes an ultra-low ballistic coefficient (< 50 Pa), semi-buoyant aircraft that deploys prior to entering the Venus atmosphere, enters without an aeroshell, and provides a long-lived (months to a year) maneuverable vehicle capable of carrying science instruments to explore the Venus upper atmosphere. In this presentation we provide an update on the air vehicle design and a low cost pathfinder mission concept that can be implemented in the near-term. The presentation also provides an overview of our plans for future trade studies, analyses, and prototyping to advance and refine the concept. We will discuss the air vehicle's entry concepts of operations (CONOPs) and atmospheric science operations. We will present a strawman concept of a VAMP pathfinder, including ballistic coefficient, planform area, percent buoyancy, wing span, vehicle mass, power supply, propulsion, materials considerations, structural elements, and instruments accommodation. In this context, we will discuss the following key factors impacting the design and performance of VAMP: Entry into the Venus atmosphere, including descent profile, heating rate, total heat load, stagnation, and acreage temperatures Impact of maximum altitude on air vehicle design and entry heating Candidate thermal protection system (TPS) requirements We will discuss the interdependencies of the above factors and the manner in which the VAMP pathfinder concept's characteristics affect the CONOPs and the science objectives. We will show how the these factors provide constraints as well as enable opportunities for novel long duration scientific studies of the Venus upper atmosphere that support Venus science goals. We will also discuss how the VAMP platform itself can facilitate some of these science measurements.

Intensities of the Venusian N2 electron-impact excited dayglow emissions

NASA Astrophysics Data System (ADS)

Fox, Jane L.; F. Hać, Nicholas E.

2013-12-01

Dayglow emissions are signatures of both the energy deposition into an atmosphere and the abundances of the species from which they arise. The first N2 dayglow emissions from Mars, the (0,5) and (0,6) bands of the N2 Vegard-Kaplan band system, were detected by the Spectroscopy for Investigations of the Characteristics of the Atmosphere of Mars (SPICAM) UV spectrometer on board the Mars Express spacecraft. The Vegard-Kaplan band system arises from the transition from the lowest N2 triplet state (A3Σu+;v') to the electronic ground state (X1Σg+;v″). It is populated by direct electron-impact excitation and by cascading from higher triplet states. The Venus UV dayglow is currently being probed by an instrument similar to SPICAM, the Spectroscopy for the Investigations of the Characteristics of the Atmosphere of Venus (SPICAV) UV spectrometer on Venus Express, but no N2 emissions have been detected. Because the N2 mixing ratios in the Venus thermosphere are larger than those in the thermosphere of Mars and the solar flux is greater at the orbit of Venus than that at Mars, we expect the Venus N2 emissions to be significantly more intense than those of Mars. A prediction of the intensities of various N2 emissions from Venus could be used to guide observations by the SPICAV and other instruments that are used to measure the Venus dayglow. Employing updated data, we here construct models of the low and high solar activity thermospheres of Venus, and we compute the integrated overhead intensities of 17 N2 band systems and limb profiles of the Vegard-Kaplan bands. The ratios of the predicted intensities of the various N2 bands at Venus to those at Mars are in the range 5.5-9.5.

Venus Data Analysis Program: Directory of Research Projects (1993-1994)

NASA Technical Reports Server (NTRS)

1994-01-01

This directory provides information about the scientific investigations funded by the NASA Venus Data Analysis Program (VDAP) during fiscal year 1993. The VDAP Directory consists of summary sheets from the proposals that were selected by NASA for funding in FY 93. Each summary sheet indicates the title, principal investigator, institution of the investigation, and information related to the objectives of the research activities proposed for FY 93. The objective of the VDAP Program is to advance our understanding of the nature and evolution of Venus. VDAP supports scientific investigation using data obtained from the Magellan, Pioneer Venus, and other Venus missions, as well as earth-based observations that contribute to understanding the physical and evolutionary properties of Venus. The program intends to enhance the scientific return from these missions by broadening the participation in the analysis of Venus data. Categories of research funded by VDAP are atmosphere, ionosphere, geology, geophysics, and mapping. The directory is intended to provide the science community with an overview of the research projects supported by this program. Research activities identified in this directory were selected for funding in FY 93 on the basis of scientific peer review conducted by the VDAP Review Panel.

Geologic map of the Mead quadrangle (V-21), Venus

USGS Publications Warehouse

Campbell, Bruce A.; Clark, David A.

2006-01-01

The Magellan spacecraft orbited Venus from August 10, 1990, until it plunged into the Venusian atmosphere on October 12, 1994. Magellan Mission objectives included (1) improving the knowledge of the geological processes, surface properties, and geologic history of Venus by analysis of surface radar characteristics, topography, and morphology and (2) improving the knowledge of the geophysics of Venus by analysis of Venusian gravity. The Mead quadrangle (V-21) of Venus is bounded by lat 0 deg and 25 deg N., long 30 deg and 60 deg E. This quadrangle is one of 62 covering Venus at 1:5,000,000 scale. Named for the largest crater on Venus, the quadrangle is dominated by effusive volcanic deposits associated with five major coronae in eastern Eistla Regio (Didilia, Pavlova, Calakomana, Isong, and Ninmah), corona-like tectonic features, and Disani Corona. The southern extremity of Bell Regio, marked by lava flows from Nyx Mons, north of the map area, forms the north-central part of the quadrangle. The shield volcanoes Kali, Dzalarhons, and Ptesanwi Montes lie south and southwest of the large corona-related flow field. Lava flows from sources east of Mead crater flood low-lying areas along the east edge of the quadrangle.

SO2 on Venus: A final cross-calibration with Pioneer Venus

NASA Technical Reports Server (NTRS)

1994-01-01

The three observing programs under NASA Grant NAG5-1913 are described. They are NSOSS, VEOEB, and PCOEB. The scientific objectives for the IUE observation program NSOSS were to: make the first ever UV observations of a near-earth asteroid (4179 Toutatis), an irregular satellite of Jupiter (Himalia), and the Saturnian satellite Hyperion; obtain the first radially-dependent information on the UV color of Saturn's rings; gather the uncontaminated UV spectra of Iapetus's bright and dark hemispheres; and obtain a spectrum of Titania to initiate the comparitive study of UV photometric properties in Uranian system. The VEOEB program studied Venus SO2, an important indicator of key processes in the Venus atmosphere and perhaps Venus surface. Based on past Pioneer Venus and IUE observations, significant SO2 variations have been interpreted as indicating that the long term atmospheric SO2 abundance may be related to large, episodic injections from the surface or interior of Venus. The PCOEB program studied the Pluto-Charon system, for which evidence of a variable UV light curve has been presented. This program is to complete the coverage of that UV light curve, since only approximately 26% has been observed.

Video auto stitching in multicamera surveillance system

NASA Astrophysics Data System (ADS)

He, Bin; Zhao, Gang; Liu, Qifang; Li, Yangyang

2012-01-01

This paper concerns the problem of video stitching automatically in a multi-camera surveillance system. Previous approaches have used multiple calibrated cameras for video mosaic in large scale monitoring application. In this work, we formulate video stitching as a multi-image registration and blending problem, and not all cameras are needed to be calibrated except a few selected master cameras. SURF is used to find matched pairs of image key points from different cameras, and then camera pose is estimated and refined. Homography matrix is employed to calculate overlapping pixels and finally implement boundary resample algorithm to blend images. The result of simulation demonstrates the efficiency of our method.

Video auto stitching in multicamera surveillance system

NASA Astrophysics Data System (ADS)

He, Bin; Zhao, Gang; Liu, Qifang; Li, Yangyang

2011-12-01

This paper concerns the problem of video stitching automatically in a multi-camera surveillance system. Previous approaches have used multiple calibrated cameras for video mosaic in large scale monitoring application. In this work, we formulate video stitching as a multi-image registration and blending problem, and not all cameras are needed to be calibrated except a few selected master cameras. SURF is used to find matched pairs of image key points from different cameras, and then camera pose is estimated and refined. Homography matrix is employed to calculate overlapping pixels and finally implement boundary resample algorithm to blend images. The result of simulation demonstrates the efficiency of our method.

Registration of 'VENUS' peanut

USDA-ARS?s Scientific Manuscript database

VENUS is a large-seeded high-oleic Virginia-type peanut (Arachis hypogaea L. subsp. hypogaea var. hypogaea) that has enhanced Sclerotinia blight and pod rot resistance when compared to the cultivar Jupiter. VENUS is the first high-oleic Virginia peanut developed for optimal performance in the South...

System selects framing rate for spectrograph camera

NASA Technical Reports Server (NTRS)

1965-01-01

Circuit using zero-order light is reflected to a photomultiplier in the incoming radiation of a spectrograph monitor to provide an error signal which controls the advancing and driving rate of the film through the camera.

A Versatile Time-Lapse Camera System Developed by the Hawaiian Volcano Observatory for Use at Kilauea Volcano, Hawaii

USGS Publications Warehouse

Orr, Tim R.; Hoblitt, Richard P.

2008-01-01

Volcanoes can be difficult to study up close. Because it may be days, weeks, or even years between important events, direct observation is often impractical. In addition, volcanoes are often inaccessible due to their remote location and (or) harsh environmental conditions. An eruption adds another level of complexity to what already may be a difficult and dangerous situation. For these reasons, scientists at the U.S. Geological Survey (USGS) Hawaiian Volcano Observatory (HVO) have, for years, built camera systems to act as surrogate eyes. With the recent advances in digital-camera technology, these eyes are rapidly improving. One type of photographic monitoring involves the use of near-real-time network-enabled cameras installed at permanent sites (Hoblitt and others, in press). Time-lapse camera-systems, on the other hand, provide an inexpensive, easily transportable monitoring option that offers more versatility in site location. While time-lapse systems lack near-real-time capability, they provide higher image resolution and can be rapidly deployed in areas where the use of sophisticated telemetry required by the networked cameras systems is not practical. This report describes the latest generation (as of 2008) time-lapse camera system used by HVO for photograph acquisition in remote and hazardous sites on Kilauea Volcano.

Lessons Learned from Radiative Transfer Simulations of the Venus Atmosphere

NASA Technical Reports Server (NTRS)

Arney, G.; Meadows, V. S.; Lincowski, A.

2017-01-01

The Venus atmosphere is extremely complex, and because of this the spectrum of Earths sister planet is likewise intricate and a challenge to model accurately. However, accurate modeling of Venus spectrum opens up multiple opportunities to better understand the planet next door, and even for understanding Venus-like planets beyond our solar system. Near-infrared (1-2.5 um, NIR) spectral windows observable on the Venus nigthside present the opportunity to probe beneath the Venusian cloud deck and measure thermal emission from the surface and lower atmosphere remotely from Earth or from orbit. These nigthside spectral windows were discovered by Allen and Crawford (1984) and have since been used measure trace gas abundances in the Venus lower atmosphere (less than 45 km), map surface emissivity varisions, and measure properties of the lower cloud deck. These windows sample radiation from below the cloud base at roughly 45 km, and pressures in this region range from roughly Earthlike (approx. 1 bar) up to 90 bars at the surface. Temperatures in this region are high: they range from about 400 K at the base of the cloud deck up to about 740 K at the surface. This high temperature and pressure presents several challenges to modelers attempting radiative transfer simulations of this region of the atmosphere, which we will review. Venus is also important to spectrally model to predict the remote observables of Venus-like exoplanets in anticipation of data from future observatories. Venus-like planets are likely one of the most common types of terrestrial planets and so simulations of them are valuable for planning observatory and detector properties of future telescopes being designed, as well as predicting the types of observations required to characterize them.

Is there uniformitarian or catastrophic tectonics on Venus?

NASA Technical Reports Server (NTRS)

Turcotte, Donald L.

1993-01-01

The distribution and modification of craters on Venus favors a near global, volcanic resurfacing event about 500 Myrs ago. Such an event indicates that the tectonic evolution of Venus was catastrophic rather than uniformitarian. The creation of a global, single-plate lithosphere on Venus about 500 Myrs ago can explain a variety of tectonic features on Venus that are not consistent with the thin lithosphere required by a uniformitarian hypothesis. A lithosphere on Venus that has thickened for 500 Myrs has a present thickness of about 300 km whereas steady-state heat loss from Venus requires a mean lithospheric thickness near 40 km. A thick lithosphere on Venus can support the high plateaus (elevations of 3-4 km) and mountain belts (up to 9 km) using the same isostatic compensation concepts applicable to the earth. If a thick lithosphere is thinned by a mantle plume, elevation is caused by thermal isostasy. The elevation due to the thinning of a 300 km thick lithosphere is about 3 km. Thus the domal elevation of Beta Regio can be explained by the same mechanism responsible for the elevation of the Hawaiian Swell. While the broad highland plateaus on Venus may be associated with thermal isostasy, the mountain belts in Ishtar Terra clearly cannot be. The high topography of Freyja Montes is almost certainly associated with underthrusting and the likely compensation mechanism is Airy isostasy associated with a thickened crust. With a density contrast delta, of 500 kg m(exp -3) an elevation of 9 km requires a crustal thickening of about 70 km. With a thick lithosphere there is no difficulty in supporting such a thick crust.

Introduction

NASA Astrophysics Data System (ADS)

Luhmann, J. G.; Tatrallyay, M.

Venus and Mars, our neighboring planets, have a long history in the human consciousness. Venus, in particular, was notable because of its brightness compared to other star-like objects in the sky. The first observations of Venus on record may be those enscribed by Babylonians on the famous "Venus tablet" in the British museum, which has been dated to ˜1700 BC. Venus has generally been associated with the female gender, except in ancient India. The name comes from the Roman goddess of love and beauty (analogous to the Babylonian Ishtar and the Greek Aphrodite). Venus was first thought by the Greeks to be two objects—a morning star "Phosphorus" and an evening star "Hesperus". Phythagoras, in 6 BC, is credited with being first to recognize they were the same object. Venus has since figured prominently in the history of physics and astronomy. The Greek Aristarchus first suggested (in ˜310-250 BC) that the planets move around the sun, but the idea lost favor to a theory of Ptolemy, which placed Earth at the center of the solar system. In the 9th-15th centuries, Arab astronomers studied Venus, and in the "new world," the Mayas used it in the organization of their calendar. In 1543, Copernicus finally published his own version of Aristarchus' vision of a heliocentric solar system, but it was probably not until Galileo, in ˜1610, telescopically observed that Venus had phases like the moon, that heliocentric theory was widely accepted (despite delays associated with the prevailing religious dogma). He announced that momentous discovery in a coded message to his contemporary Kepler (a usual practice of the time), which translated to "the mother of the loves imitates the phases of Cynthia".

Understanding Divergent Evolution Among Earth-like Planets, the Case for Venus Exploration

NASA Astrophysics Data System (ADS)

Crisp, D.

2001-11-01

Venus was once considered to be Earth's twin because of its similar size, mass, and solar distance. Prevailing theories early in the 20th century alternately characterized it as a hot, lifeless desert or a cool, habitable swamp. Venus was therefore the target of intense scrutiny during the first three decades of the space age. Those studies found that although Venus and Earth apparently formed in similar parts of the solar nebula, sharing common inventories of refractory and volatile constituents, these two planets followed dramatically different evolutionary paths. While the Earth evolved into the only known oasis for life, Venus developed an almost unimaginably inhospitable environment for such an Earth-like planet. Some features of Venus can be understood as products of its location in the solar system, but other properties and processes governing the evolution and present state of its interior, surface, and climate remain mysterious or even contradictory. A more comprehensive understanding of these factors is clearly essential as NASA embarks on efforts to detect and then characterize Earth-like planets in other solar systems. As part of the National Research Council's effort to identify themes and priorities for solar system exploration over the next decade, an open community panel was formed to provide input on future Venus exploration. A comprehensive investigation of the processes driving the divergent evolution of Venus is emerging as the primary focus. In other words, why is Venus a failed Earth? From this theme, we will define specific measurement objectives, instrument requirements, and mission requirements. Priorities will then be based on a number of factors including the needs for simultaneous or correlative measurements, technology readiness, and available opportunities.

Cloud top structure of Venus revealed by Subaru/COMICS mid-infrared images

NASA Astrophysics Data System (ADS)

Sato, T. M.; Sagawa, H.; Kouyama, T.; Mitsuyama, K.; Satoh, T.; Ohtsuki, S.; Ueno, M.; Kasaba, Y.; Nakamura, M.; Imamura, T.

2014-11-01

We have investigated the cloud top structure of Venus by analyzing ground-based images taken at the mid-infrared wavelengths of 8.66 μm and 11.34 μm. Venus at a solar phase angle of ∼90°, with the morning terminator in view, was observed by the Cooled Mid-Infrared Camera and Spectrometer (COMICS), mounted on the 8.2-m Subaru Telescope, during the period October 25-29, 2007. The disk-averaged brightness temperatures for the observation period are ∼230 K and ∼238 K at 8.66 μm and 11.34 μm, respectively. The obtained images with good signal-to-noise ratio and with high spatial resolution (∼200 km at the sub-observer point) provide several important findings. First, we present observational evidence, for the first time, of the possibility that the westward rotation of the polar features (the hot polar spots and the surrounding cold collars) is synchronized between the northern and southern hemispheres. Second, after high-pass filtering, the images reveal that streaks and mottled and patchy patterns are distributed over the entire disk, with typical amplitudes of ∼0.5 K, and vary from day to day. The detected features, some of which are similar to those seen in past UV images, result from inhomogeneities of both the temperature and the cloud top altitude. Third, the equatorial center-to-limb variations of brightness temperatures have a systematic day-night asymmetry, except those on October 25, that the dayside brightness temperatures are higher than the nightside brightness temperatures by 0-4 K under the same viewing geometry. Such asymmetry would be caused by the propagation of the migrating semidiurnal tide. Finally, by applying the lapse rates deduced from previous studies, we demonstrate that the equatorial center-to-limb curves in the two spectral channels give access to two parameters: the cloud scale height H and the cloud top altitude zc. The acceptable models for data on October 25 are obtained at H = 2.4-4.3 km and zc = 66-69 km; this supports previous results determined from spacecraft observations.

Exploration of Venus' Deep Atmosphere and Surface Environment

NASA Technical Reports Server (NTRS)

Glaze, L. S.; Amato, M.; Garvin, J. B.; Johnson, N. M.

2017-01-01

Venus formed in the same part of our solar system as Earth, apparently from similar materials. Although both planets are about the same size, their differences are profound. Venus and Earth experienced vastly different evolutionary pathways resulting in unexplained differences in atmospheric composition and dynamics, as well as in geophysical processes of the planetary surfaces and interiors. Understanding when and why the evolutionary pathways of Venus and Earth diverged is key to understanding how terrestrial planets form and how their atmospheres and surfaces evolve. Measurements made in situ, within the near-surface or surface environment, are critical to addressing unanswered questions. We have made substantial progress modernizing and maturing pressure vessel technologies to enable science operations in the high temperature and pressure near-surface/surfaceenvironment of Venus.

High Temperature, Wireless Seismometer Sensor for Venus

NASA Technical Reports Server (NTRS)

Ponchak, George E.; Scardelletti, Maximilian C.; Taylor, Brandt; Beard, Steve; Meredith, Roger D.; Beheim, Glenn M.; Hunter Gary W.; Kiefer, Walter S.

2012-01-01

Space agency mission plans state the need to measure the seismic activity on Venus. Because of the high temperature on Venus (462? C average surface temperature) and the difficulty in placing and wiring multiple sensors using robots, a high temperature, wireless sensor using a wide bandgap semiconductor is an attractive option. This paper presents the description and proof of concept measurements of a high temperature, wireless seismometer sensor for Venus. A variation in inductance of a coil caused by the movement of an aluminum probe held in the coil and attached to a balanced leaf-spring seismometer causes a variation of 700 Hz in the transmitted signal from the oscillator/sensor system at 426? C. This result indicates that the concept may be used on Venus.

The International VEGA "Venus-Halley" (1984-1986) Experiment: Description and Scientific Objectives

NASA Technical Reports Server (NTRS)

1985-01-01

The Venus-Halley (Vega) project will provide a unique opportunity to combine a mission over Venus with a transfer flight to Halley's comet. This project is based on three research goals: (1) to study the surface of Venus; (2) to study the air circulation on Venus and its meteorological parameters; and (3) to study Halley's comet. The objective of the study of Halley's comet is to: determine the physical characteristics of its nucleus; define the structure and dynamics of the coma around the nucleus; define the gas composition near the nucleus; investigate the dust particle distribution as a function of mass at various distances from the nucleus; and investigate the solar wind interaction with the atmosphere and ionosphere of the comet.

The Venus nitric oxide night airglow - Model calculations based on the Venus Thermospheric General Circulation Model

NASA Technical Reports Server (NTRS)

Bougher, S. W.; Gerard, J. C.; Stewart, A. I. F.; Fesen, C. G.

1990-01-01

The mechanism responsible for the Venus nitric oxide (0,1) delta band nightglow observed in the Pioneer Venus Orbiter UV spectrometer (OUVS) images was investigated using the Venus Thermospheric General Circulation Model (Dickinson et al., 1984), modified to include simple odd nitrogen chemistry. Results obtained for the solar maximum conditions indicate that the recently revised dark-disk average NO intensity at 198.0 nm, based on statistically averaged OUVS measurements, can be reproduced with minor modifications in chemical rate coefficients. The results imply a nightside hemispheric downward N flux of (2.5-3) x 10 to the 9th/sq cm sec, corresponding to the dayside net production of N atoms needed for transport.

The Pioneer Venus Orbiter: 11 years of data. A laboratory for atmospheres seminar talk

NASA Technical Reports Server (NTRS)

Kasprzak, W. T.

1990-01-01

The Pioneer Venus Orbiter has been in operation since orbit insertion on December 4, 1978. For the past 11 years, it has been acquiring data in the salient features of the planet, its atmosphere, ionosphere, and interaction with the solar wind. A few of the results of this mission are summarized and their contribution to our general understanding of the planet Venus is discussed. Although Earth and Venus are often called twin planets, they are only superficially similar. Possessing no obvious evidence of plate tectonics, lacking water and an intrinsic magnetic field, and having a hot, dense carbon dioxide atmosphere with sulfuric acid clouds makes Venus a unique object of study by the Orbiter's instruments.

Change detection and characterization of volcanic activity using ground based low-light and near infrared cameras to monitor incandescence and thermal signatures

NASA Astrophysics Data System (ADS)

Harrild, M.; Webley, P.; Dehn, J.

2014-12-01

Knowledge and understanding of precursory events and thermal signatures are vital for monitoring volcanogenic processes, as activity can often range from low level lava effusion to large explosive eruptions, easily capable of ejecting ash up to aircraft cruise altitudes. Using ground based remote sensing techniques to monitor and detect this activity is essential, but often the required equipment and maintenance is expensive. Our investigation explores the use of low-light cameras to image volcanic activity in the visible to near infrared (NIR) portion of the electromagnetic spectrum. These cameras are ideal for monitoring as they are cheap, consume little power, are easily replaced and can provide near real-time data. We focus here on the early detection of volcanic activity, using automated scripts, that capture streaming online webcam imagery and evaluate image pixel brightness values to determine relative changes and flag increases in activity. The script is written in Python, an open source programming language, to reduce the overall cost to potential consumers and increase the application of these tools across the volcanological community. In addition, by performing laboratory tests to determine the spectral response of these cameras, a direct comparison of collocated low-light and thermal infrared cameras has allowed approximate eruption temperatures and effusion rates to be determined from pixel brightness. The results of a field campaign in June, 2013 to Stromboli volcano, Italy, are also presented here. Future field campaigns to Latin America will include collaborations with INSIVUMEH in Guatemala, to apply our techniques to Fuego and Santiaguito volcanoes.

Change detection and characterization of volcanic activity using ground based low-light and near infrared cameras to monitor incandescence and thermal signatures

NASA Astrophysics Data System (ADS)

Harrild, Martin; Webley, Peter; Dehn, Jonathan

2015-04-01

Knowledge and understanding of precursory events and thermal signatures are vital for monitoring volcanogenic processes, as activity can often range from low level lava effusion to large explosive eruptions, easily capable of ejecting ash up to aircraft cruise altitudes. Using ground based remote sensing techniques to monitor and detect this activity is essential, but often the required equipment and maintenance is expensive. Our investigation explores the use of low-light cameras to image volcanic activity in the visible to near infrared (NIR) portion of the electromagnetic spectrum. These cameras are ideal for monitoring as they are cheap, consume little power, are easily replaced and can provide near real-time data. We focus here on the early detection of volcanic activity, using automated scripts, that capture streaming online webcam imagery and evaluate image pixel brightness values to determine relative changes and flag increases in activity. The script is written in Python, an open source programming language, to reduce the overall cost to potential consumers and increase the application of these tools across the volcanological community. In addition, by performing laboratory tests to determine the spectral response of these cameras, a direct comparison of collocated low-light and thermal infrared cameras has allowed approximate eruption temperatures and effusion rates to be determined from pixel brightness. The results of a field campaign in June, 2013 to Stromboli volcano, Italy, are also presented here. Future field campaigns to Latin America will include collaborations with INSIVUMEH in Guatemala, to apply our techniques to Fuego and Santiaguito volcanoes.

The Interaction of Mantle Plumes with Surface Thermal and Chemical Boundary Layers: Applications to Hotspots on Venus

NASA Technical Reports Server (NTRS)

Smrekar, S.; Parmentier, E.

1994-01-01

Describes the characteristics of possible hotspots on Venus, the approach used to simulate mantle upwelling, model results, and presents the implications for the properties of plumes and the lithosphere, hotspot evolution, and resurfacing on Venus.

Dynamic behavior of solar wind as revealed by a correlation study of magnetic fields observed at the Venus and Earth orbits

NASA Technical Reports Server (NTRS)

Marubashi, K.

1995-01-01

Correlations between interplanetary magnetic fields (IMFs) at 0.72 AU and 1.0 AU have been examined using data sets obtained from the Pioneer Venus orbiter and Earth-orbiting spacecraft. While the two-sector structures are evident in long-term variations at these two heliocentric distances, the corresponding auto-correlation coefficients are consistently smaller at 1.0 AU than at 0.72 AU. This suggests that the IMF structures become less persistent at 1.0 AU due to the effects of changing solar wind dynamics between the Venus and Earth orbits. Short-term variations exhibit generally poor correlations between IMFs near Venus and those near Earth, though good correlations are sometimes obtained for well-defined structures when the Sun, Venus, and Earth are closely aligned. The rather poor correlations in the background streams indicate that the IMFs are still changing between the Venus and Earth orbits under the strong influence of solar wind dynamics.

Gravity field of Venus - A preliminary analysis

NASA Technical Reports Server (NTRS)

Phillips, R. J.; Sjogren, W. L.; Abbott, E. A.; Smith, J. C.; Wimberly, R. N.; Wagner, C. A.

1979-01-01

The gravitational field of Venus obtained by tracking the Pioneer Venus Orbiter is examined. For each spacecraft orbit, two hours of Doppler data centered around periapsis were used to estimate spacecraft position and velocity and the velocity residuals obtained were spline fit and differentiated to produce line of sight gravitational accelerations. Consistent variations in line of sight accelerations from orbit to orbit reveal the presence of gravitational anomalies. A simulation of isostatic compensation for an elevated region on the surface of Venus indicates that the mean depth of compensation is no greater than about 100 km. Gravitational spectra obtained from a Fourier analysis of line of sight accelerations from selected Venus orbits are compared to the earth's gravitational spectrum and spherical harmonic gravitational potential power spectra of the earth, the moon and Mars. The Venus power spectrum is found to be remarkably similar to that of the earth, however systematic variations in the harmonics suggest differences in dynamic processes or lithospheric behavior.

Structure of the middle atmosphere of Venus and future observation with PFS on Venus Express.

NASA Astrophysics Data System (ADS)

Zasova, L. V.; Formisano, V.; Moroz, V. I.; Ignatiev, N. I.; Khatountsev, I. A.

Investigation of the middle atmosphere of Venus (55 -- 100 km) will allow to advance our knowledge about the most puzzling phenomena of the Venus dynamics -- its superrotation. More than 70% of all absorbed by Venus Solar energy is deposited there, results in the thermal tides generation and giving energy to support the superrotation. The importance of the tides in the middle atmosphere is manifested by the tidal character of the local time variation of the structure of the thermal field, zonal wind field (especially, behavior of the wind speed in the mid latitude jet), upper clouds, with amplitudes depending on the altitude and latitude. Investigation of the middle atmosphere is a scientific goal of the long wavelength channel of PFS on Venus Express, as well as of its short wavelength channel (the latter on the day side). The 3D temperature, aerosol, thermal wind and SO2 abundance fields, spatial distribution of abundance of H2O (possibly vertical profile), CO, HCl, HF will be obtained.

Was Venus the First Habitable World of our Solar System?

PubMed Central

Way, M. J.; Del Genio, Anthony D.; Kiang, Nancy Y.; Sohl, Linda E.; Grinspoon, David H.; Aleinov, Igor; Kelley, Maxwell; Clune, Thomas

2017-01-01

Present-day Venus is an inhospitable place with surface temperatures approaching 750K and an atmosphere 90 times as thick as Earth's. Billions of years ago the picture may have been very different. We have created a suite of 3-D climate simulations using topographic data from the Magellan mission, solar spectral irradiance estimates for 2.9 and 0.715 Gya, present-day Venus orbital parameters, an ocean volume consistent with current theory, and an atmospheric composition estimated for early Venus. Using these parameters we find that such a world could have had moderate temperatures if Venus had a rotation period slower than ~16 Earth days, despite an incident solar flux 46−70% higher than Earth receives. At its current rotation period, Venus’s climate could have remained habitable until at least 715 million years ago. These results demonstrate the role rotation and topography play in understanding the climatic history of Venus-like exoplanets discovered in the present epoch. PMID:28408771

Features on Venus generated by plate boundary processes

NASA Technical Reports Server (NTRS)

Mckenzie, Dan; Ford, Peter G.; Johnson, Catherine; Parsons, Barry; Sandwell, David; Saunders, Stephen; Solomon, Sean C.

1992-01-01

Various observations suggest that there are processes on Venus that produce features similar to those associated with plate boundaries on earth. Synthetic aperture radar images of Venus, taken with a radar whose wavelength is 12.6 cm, are compared with GLORIA images of active plate boundaries, obtained with a sound source whose wavelength is 23 cm. Features similar to transform faults and to abyssal hills on slow and fast spreading ridges can be recognized within the Artemis region of Venus but are not clearly visible elsewhere. The composition of the basalts measured by the Venera 13 and 14 and the Vega 2 spacecraft corresponds to that expected from adiabatic decompression, like that which occurs beneath spreading ridges on earth. Structures that resemble trenches are widespread on Venus and show the same curvature and asymmetry as they do on earth. These observations suggest that the same simple geophysical models that have been so successfully used to understand the tectonics of earth can also be applied to Venus.

The development of a multifunction lens test instrument by using computer aided variable test patterns

NASA Astrophysics Data System (ADS)

Chen, Chun-Jen; Wu, Wen-Hong; Huang, Kuo-Cheng

2009-08-01

A multi-function lens test instrument is report in this paper. This system can evaluate the image resolution, image quality, depth of field, image distortion and light intensity distribution of the tested lens by changing the tested patterns. This system consists of a tested lens, a CCD camera, a linear motorized stage, a system fixture, an observer LCD monitor, and a notebook for pattern providing. The LCD monitor displays a serious of specified tested patterns sent by the notebook. Then each displayed pattern goes through the tested lens and images in the CCD camera sensor. Consequently, the system can evaluate the performance of the tested lens by analyzing the image of CCD camera with special designed software. The major advantage of this system is that it can complete whole test quickly without interruption due to part replacement, because the tested patterns are statically displayed on monitor and controlled by the notebook.

The Surface of Venus

NASA Astrophysics Data System (ADS)

Ivanov, M. A.; Head, J. W.

2018-03-01

This chapter reviews the conditions under which the basic landforms of Venus formed, interprets their nature, and analyzes their local, regional, and global age relationships. The strong greenhouse effect on Venus causes hyper-dry, almost stagnant near-surface environments. These conditions preclude water-driven, and suppress wind-related, geological processes; thus, the common Earth-like water-generated geological record of sedimentary materials does not currently form on Venus. Three geological processes are important on the planet: volcanism, tectonics, and impact cratering. The small number of impact craters on Venus ( 1,000) indicates that their contribution to resurfacing is minor. Volcanism and tectonics are the principal geological processes operating on Venus during its observable geologic history. Landforms of the volcanic and tectonic nature have specific morphologies, which indicate different modes of formation, and their relationships permit one to establish their relative ages. Analysis of these relationships at the global scale reveals that three distinct regimes of resurfacing comprise the observable geologic history of Venus: (1) the global tectonic regime, (2) the global volcanic regime, and (3) the network rifting-volcanism regime. During the earlier global tectonic regime, tectonic resurfacing dominated. Tectonic deformation at this time caused formation of strongly tectonized terrains such as tessera, and deformational belts. Exposures of these units comprise 20% of the surface of Venus. The apparent beginning of the global tectonic regime is related to the formation of tessera, which is among the oldest units on Venus. The age relationships among the tessera structures indicate that this terrain is the result of crustal shortening. During the global volcanic regime, volcanism overwhelmed tectonic activity and caused formation of vast volcanic plains that compose 60% of the surface of Venus. The plains show a clear stratigraphic sequence from older shield plains to younger regional plains. The distinctly different morphologies of the plains indicate different volcanic formation styles ranging from eruption through broadly distributed local sources of shield plains to the volcanic flooding of regional plains. The density of impact craters on units of the tectonic and volcanic regimes suggests that these regimes characterized about the first one-third of the visible geologic history of Venus. During this time, 80%–85% of the surface of the planet was renovated. The network rifting-volcanism regime characterized the last two-thirds of the visible geologic history of Venus. The major components of the regime include broadly synchronous lobate plains and rift zones. Although the network rifting-volcanism regime characterized 2/3 of the visible geologic history of Venus, only 15%–20% of the surface was resurfaced during this time. This means that the level of endogenous activity during this time has dropped by about an order of magnitude compared with the earlier regimes.

Simulations of Variability and Waves at Cloud Altitudes Using a Venus Middle Atmosphere General Circulation Model

NASA Astrophysics Data System (ADS)

Parish, H. F.; Mitchell, J.

2017-12-01

We have developed a Venus general circulation model, the Venus Middle atmosphere Model (VMM), to simulate the atmosphere from just below the cloud deck 40 km altitude to around 100 km altitude. Our primary goal is to assess the influence of waves on the variability of winds and temperatures observed around Venus' cloud deck. Venus' deep atmosphere is not simulated directly in the VMM model, so the effects of waves propagating upwards from the lower atmosphere is represented by forcing at the lower boundary of the model. Sensitivity tests allow appropriate amplitudes for the wave forcing to be determined by comparison with Venus Express and probe measurements and allow the influence of waves on the cloud-level atmosphere to be investigated. Observations at cloud altitudes are characterized by waves with a wide variety of periods and wavelengths, including gravity waves, thermal tides, Rossby waves, and Kelvin waves. These waves may be generated within the cloud deck by instabilities, or may propagate up from the deep atmosphere. Our development of the VMM is motivated by the fact that the circulation and dynamics between the surface and the cloud levels are not well measured and wind velocities below 40 km altitude cannot be observed remotely, so we focus on the dynamics at cloud levels and above. Initial results from the VMM with a simplified radiation scheme have been validated by comparison with Pioneer Venus and Venus Express observations and show reasonable agreement with the measurements.

Venus-Earth-Mars: comparative climatology and the search for life in the solar system.

PubMed

Launius, Roger D

2012-09-19

Both Venus and Mars have captured the human imagination during the twentieth century as possible abodes of life. Venus had long enchanted humans-all the more so after astronomers realized it was shrouded in a mysterious cloak of clouds permanently hiding the surface from view. It was also the closest planet to Earth, with nearly the same size and surface gravity. These attributes brought myriad speculations about the nature of Venus, its climate, and the possibility of life existing there in some form. Mars also harbored interest as a place where life had or might still exist. Seasonal changes on Mars were interpreted as due to the possible spread and retreat of ice caps and lichen-like vegetation. A core element of this belief rested with the climatology of these two planets, as observed by astronomers, but these ideas were significantly altered, if not dashed during the space age. Missions to Venus and Mars revealed strikingly different worlds. The high temperatures and pressures found on Venus supported a "runaway greenhouse theory," and Mars harbored an apparently lifeless landscape similar to the surface of the Moon. While hopes for Venus as an abode of life ended, the search for evidence of past life on Mars, possibly microbial, remains a central theme in space exploration. This survey explores the evolution of thinking about the climates of Venus and Mars as life-support systems, in comparison to Earth.

Venus-Earth-Mars: Comparative Climatology and the Search for Life in the Solar System

PubMed Central

Launius, Roger D.

2012-01-01

Both Venus and Mars have captured the human imagination during the twentieth century as possible abodes of life. Venus had long enchanted humans—all the more so after astronomers realized it was shrouded in a mysterious cloak of clouds permanently hiding the surface from view. It was also the closest planet to Earth, with nearly the same size and surface gravity. These attributes brought myriad speculations about the nature of Venus, its climate, and the possibility of life existing there in some form. Mars also harbored interest as a place where life had or might still exist. Seasonal changes on Mars were interpreted as due to the possible spread and retreat of ice caps and lichen-like vegetation. A core element of this belief rested with the climatology of these two planets, as observed by astronomers, but these ideas were significantly altered, if not dashed during the space age. Missions to Venus and Mars revealed strikingly different worlds. The high temperatures and pressures found on Venus supported a “runaway greenhouse theory,” and Mars harbored an apparently lifeless landscape similar to the surface of the Moon. While hopes for Venus as an abode of life ended, the search for evidence of past life on Mars, possibly microbial, remains a central theme in space exploration. This survey explores the evolution of thinking about the climates of Venus and Mars as life-support systems, in comparison to Earth. PMID:25371106

Venus-Earth-Mars: Comparative Climatology and the Search for Life in the Solar System

NASA Astrophysics Data System (ADS)

Launius, Roger D.

2012-09-01

Both Venus and Mars have captured the human imagination during the twentieth century as possible abodes of life. Venus had long enchanted humans - all the more so after astronomers realized it was shrouded in a mysterious cloak of clouds permanently hiding the surface from view. It was also the closest planet to Earth, with nearly the same size and surface gravity. These attributes brought myriad speculations about the nature of Venus, its climate, and the possibility of life existing there in some form. Mars also harbored interest as a place where life had or might still exist. Seasonal changes on Mars were interpreted as due to the possible spread and retreat of ice caps and lichen-like vegetation. A core element of this belief rested with the climatology of these two planets, as observed by astronomers, but these ideas were significantly altered, if not dashed during the space age. Missions to Venus and Mars revealed strikingly different worlds. The high temperatures and pressures found on Venus supported a "runaway greenhouse theory," and Mars harbored an apparently lifeless landscape similar to the surface of the Moon. While hopes for Venus as an abode of life ended, the search for evidence of past life on Mars, possibly microbial, remains a central theme in space exploration. This survey explores the evolution of thinking about the climates of Venus and Mars as life-support systems, in comparison to Earth.

Infrared-enhanced TV for fire detection

NASA Technical Reports Server (NTRS)

Hall, J. R.

1978-01-01

Closed-circuit television is superior to conventional smoke or heat sensors for detecting fires in large open spaces. Single TV camera scans entire area, whereas many conventional sensors and maze of interconnecting wiring might be required to get same coverage. Camera is monitored by person who would trip alarm if fire were detected, or electronic circuitry could process camera signal for fully-automatic alarm system.

Cameras Monitor Spacecraft Integrity to Prevent Failures

NASA Technical Reports Server (NTRS)

2014-01-01

The Jet Propulsion Laboratory contracted Malin Space Science Systems Inc. to outfit Curiosity with four of its cameras using the latest commercial imaging technology. The company parlayed the knowledge gained under working with NASA to develop an off-the-shelf line of cameras, along with a digital video recorder, designed to help troubleshoot problems that may arise on satellites in space.

Achieving thermography with a thermal security camera using uncooled amorphous silicon microbolometer image sensors

NASA Astrophysics Data System (ADS)

Wang, Yu-Wei; Tesdahl, Curtis; Owens, Jim; Dorn, David

2012-06-01

Advancements in uncooled microbolometer technology over the last several years have opened up many commercial applications which had been previously cost prohibitive. Thermal technology is no longer limited to the military and government market segments. One type of thermal sensor with low NETD which is available in the commercial market segment is the uncooled amorphous silicon (α-Si) microbolometer image sensor. Typical thermal security cameras focus on providing the best image quality by auto tonemaping (contrast enhancing) the image, which provides the best contrast depending on the temperature range of the scene. While this may provide enough information to detect objects and activities, there are further benefits of being able to estimate the actual object temperatures in a scene. This thermographic ability can provide functionality beyond typical security cameras by being able to monitor processes. Example applications of thermography[2] with thermal camera include: monitoring electrical circuits, industrial machinery, building thermal leaks, oil/gas pipelines, power substations, etc...[3][5] This paper discusses the methodology of estimating object temperatures by characterizing/calibrating different components inside a thermal camera utilizing an uncooled amorphous silicon microbolometer image sensor. Plots of system performance across camera operating temperatures will be shown.

Calibration Method for IATS and Application in Multi-Target Monitoring Using Coded Targets

NASA Astrophysics Data System (ADS)

Zhou, Yueyin; Wagner, Andreas; Wunderlich, Thomas; Wasmeier, Peter

2017-06-01

The technique of Image Assisted Total Stations (IATS) has been studied for over ten years and is composed of two major parts: one is the calibration procedure which combines the relationship between the camera system and the theodolite system; the other is the automatic target detection on the image by various methods of photogrammetry or computer vision. Several calibration methods have been developed, mostly using prototypes with an add-on camera rigidly mounted on the total station. However, these prototypes are not commercially available. This paper proposes a calibration method based on Leica MS50 which has two built-in cameras each with a resolution of 2560 × 1920 px: an overview camera and a telescope (on-axis) camera. Our work in this paper is based on the on-axis camera which uses the 30-times magnification of the telescope. The calibration consists of 7 parameters to estimate. We use coded targets, which are common tools in photogrammetry for orientation, to detect different targets in IATS images instead of prisms and traditional ATR functions. We test and verify the efficiency and stability of this monitoring method with multi-target.

Astronaut George Nelson working on Comet Halley Active monitoring program

NASA Image and Video Library

1986-01-14

61C-05-026 (14 Jan. 1986) --- Astronaut George D. Nelson smiles for a fellow crew man's 35mm camera exposure while participating in the Comet Halley active monitoring program (CHAMP). Camera equipment and a protective shroud used to eliminate all cabin light interference surround the mission specialist. This is the first of three 1986 missions which are scheduled to monitor the rare visit by the comet. The principal investigators for CHAMP are S. Alan Stern of the Laboratory for Atmospheric and Space Physics at the University of Colorado; and Dr. Stephen Mende of Lockheed Palo Alto Research Laboratory.

Using oblique digital photography for alluvial sandbar monitoring and low-cost change detection

USGS Publications Warehouse

Tusso, Robert B.; Buscombe, Daniel D.; Grams, Paul E.

2015-01-01

The maintenance of alluvial sandbars is a longstanding management interest along the Colorado River in Grand Canyon. Resource managers are interested in both the long-term trend in sandbar condition and the short-term response to management actions, such as intentional controlled floods released from Glen Canyon Dam. Long-term monitoring is accomplished at a range of scales, by a combination of annual topographic survey at selected sites, daily collection of images from those sites using novel, autonomously operating, digital camera systems (hereafter referred to as 'remote cameras'), and quadrennial remote sensing of sandbars canyonwide. In this paper, we present results from the remote camera images for daily changes in sandbar topography.

Submillimeter mapping of mesospheric minor species on Venus with ALMA

NASA Astrophysics Data System (ADS)

Encrenaz, T.; Moreno, R.; Moullet, A.; Lellouch, E.; Fouchet, T.

2015-08-01

Millimeter and submillimeter heterodyne spectroscopy offers the possibility of probing the mesosphere of Venus and monitoring minor species and winds. ALMA presents a unique opportunity to map mesospheric species of Venus. During Cycle 0, we have observed Venus on November 14 and 15, 2011, using the compact configuration of ALMA. The diameter of Venus was 11″ and the illumination factor was about 90%. Maps of CO, SO, SO2 and HDO have been built from transitions recorded in the 335-347 GHz frequency range. A mean mesospheric thermal profile has been inferred from the analysis of the CO transition at the disk center, to be used in support of minor species retrieval. Maps of SO and SO2 abundance show significant local variations over the disk and contrast variations by as much as a factor 4. In the case of SO2, the spatial distribution appears more "patchy", i.e. shows short-scale structures apparently disconnected from day-side and latitudinal variations. For both molecules, significant changes occur over a timescale of one day. From the disk averaged spectrum of SO recorded on November 14 at 346.528 GHz, we find that the best fit is obtained with a cutoff in the SO vertical distribution at 88±2 km and a uniform mixing ratio of 8.0±2.0 ppb above this level. The SO2 map of November 14, derived from the weaker transition at 346.652 GHz, shows a clear maximum in the morning side at low latitudes, which is less visible in the map of November 15. We find that the best fit for SO2 is obtained for a cutoff in the vertical distribution at 88±3 km and a uniform mixing ratio of 12.0±3.5 ppb above this level. The HDO maps retrieved from the 335.395 GHz show some enhancement in the northern hemisphere, but less contrasted variations than for the sulfur species maps, with little change between November 14 and 15. Assuming a typical D/H ratio of 200 times the terrestrial value in the mesosphere of Venus, we find that the disk averaged HDO spectrum is best fitted with a uniform H2O mixing ratio of 2.5±0.6 ppm (corresponding to a HDO mixing ratio of 0.165±0.040 ppm). We note that our spectrum is also compatible with a H2O mixing ratio of 1.5 ppm in the 80-90 km altitude range, and a mixing ratio of 3 ppm outside this range, as suggested by the photochemical model of Zhang et al. (2012, Icarus, vol. 217, pp. 714-739). Our results are in good general agreement with previous single dish submillimeter observations of Sandor and Clancy (2005, Icarus, vol. 177, pp. 129-143), Gurwell et al. (2007, Icarus, vol. 188, p. 288), and Sandor et al. (2010, Icarus, vol. 208, pp. 49-60; 2012, Icarus, vol. 217, pp. 839-844) and with SPICAV/Venus Express results of Fedorova et al. (2008, J. Geophys. Res., vol. 113, p. E00B25) and Belyaev et al. (2012).

An improved camera trap for amphibians, reptiles, small mammals, and large invertebrates

USGS Publications Warehouse

Hobbs, Michael T.; Brehme, Cheryl S.

2017-01-01

Camera traps are valuable sampling tools commonly used to inventory and monitor wildlife communities but are challenged to reliably sample small animals. We introduce a novel active camera trap system enabling the reliable and efficient use of wildlife cameras for sampling small animals, particularly reptiles, amphibians, small mammals and large invertebrates. It surpasses the detection ability of commonly used passive infrared (PIR) cameras for this application and eliminates problems such as high rates of false triggers and high variability in detection rates among cameras and study locations. Our system, which employs a HALT trigger, is capable of coupling to digital PIR cameras and is designed for detecting small animals traversing small tunnels, narrow trails, small clearings and along walls or drift fencing.

An improved camera trap for amphibians, reptiles, small mammals, and large invertebrates.

PubMed

Hobbs, Michael T; Brehme, Cheryl S

2017-01-01

Camera traps are valuable sampling tools commonly used to inventory and monitor wildlife communities but are challenged to reliably sample small animals. We introduce a novel active camera trap system enabling the reliable and efficient use of wildlife cameras for sampling small animals, particularly reptiles, amphibians, small mammals and large invertebrates. It surpasses the detection ability of commonly used passive infrared (PIR) cameras for this application and eliminates problems such as high rates of false triggers and high variability in detection rates among cameras and study locations. Our system, which employs a HALT trigger, is capable of coupling to digital PIR cameras and is designed for detecting small animals traversing small tunnels, narrow trails, small clearings and along walls or drift fencing.

Celestial mechanics experiment.

PubMed

Anderson, J D; Pease, G E; Efron, L; Tausworthe, R C

1967-12-29

Equipment on Mariner V has yielded values for the masses of Moon and Venus more accurate than any previously reported. Range and Doppler radio tracking data necessary for precise space navigation of the spacecraft from Earth to Venus can also be used to obtain data on the orbits of Earth and Venus.

Low Cost Wireless Network Camera Sensors for Traffic Monitoring

DOT National Transportation Integrated Search

2012-07-01

Many freeways and arterials in major cities in Texas are presently equipped with video detection cameras to : collect data and help in traffic/incident management. In this study, carefully controlled experiments determined : the throughput and output...

Development of a tunable Fabry-Perot interferometer UV camera for monitoring sulfur dioxide emissions

NASA Astrophysics Data System (ADS)

Tamminen, J.; Kujanpää, J.; Ojanen, H.; Saari, H.; Näkki, I.; Tukiainen, S.; Kyrölä, E.

2017-12-01

We present a novel UV camera for sulfur dioxide emission monitoring.The camera is equipped with a piezo-actuated Fabry-Perot interferometer allowing thefilter transmission to be tuned to match the differential absorption features ofsulfur dioxide in the wavelength region 305-320 nm. The differential absorption structuresare exploited to reduce the interfering effects of weakly wavelength dependent absorbers, suchas aerosols and black carbon, present in the exhaust gas. A data processing algorithm basedon two air gaps of the filter is presented allowing collection of a sufficient signal-to-noise ratio fordetecting sulfur dioxide in the ship plumes even in the designated emission control areas, such as the Baltic Seawhere the sulfur content limit of fuel oil is 0.1 %. First field tests performed inLänsisatama harbour, Helsinki Finland, indicate that sulfur dioxide can be detectedin ship plumes. The camera is light-weight and can be mounted to a drone.

Visualization of Porphyrin-Based Photosensitizer Distribution from Fluorescence Images In Vivo Using an Optimized RGB Camera

NASA Astrophysics Data System (ADS)

Liu, L.; Huang, Zh.; Qiu, Zh.; Li, B.

2018-01-01

A handheld RGB camera was developed to monitor the in vivo distribution of porphyrin-based photosensitizer (PS) hematoporphyrin monomethyl ether (HMME) in blood vessels during photodynamic therapy (PDT). The focal length, f-number, International Standardization Organization (ISO) sensitivity, and shutter speed of the camera were optimized for the solution sample with various HMME concentrations. After the parameter optimization, it was found that the red intensity value of the fluorescence image was linearly related to the fluorescence intensity under investigated conditions. The RGB camera was then used to monitor the in vivo distribution of HMME in blood vessels in a skin-fold window chamber model. The red intensity value of the recorded RGB fluorescence image was found to be linearly correlated to HMME concentrations in the range 0-24 μM. Significant differences in the red to green intensity ratios were observed between the blood vessels and the surrounding tissue.

Automatic lightning detection and photographic system

NASA Technical Reports Server (NTRS)

Wojtasinski, R. J.; Holley, L. D.; Gray, J. L.; Hoover, R. B. (Inventor)

1972-01-01

A system is presented for monitoring and recording lightning strokes within a predetermined area with a camera having an electrically operated shutter with means for advancing the film in the camera after activating the shutter. The system includes an antenna for sensing lightning strikes which, in turn, generates a signal that is fed to an electronic circuit which generates signals for operating the shutter of the camera. Circuitry is provided for preventing activation of the shutter as the film in the camera is being advanced.

IR Camera Report for the 7 Day Production Test

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holloway, Michael Andrew

2016-02-22

The following report gives a summary of the IR camera performance results and data for the 7 day production run that occurred from 10 Sep 2015 thru 16 Sep 2015. During this production run our goal was to see how well the camera performed its task of monitoring the target window temperature with our improved alignment procedure and emissivity measurements. We also wanted to see if the increased shielding would be effective in protecting the camera from damage and failure.

New Approach for Environmental Monitoring and Plant Observation Using a Light-Field Camera

NASA Astrophysics Data System (ADS)

Schima, Robert; Mollenhauer, Hannes; Grenzdörffer, Görres; Merbach, Ines; Lausch, Angela; Dietrich, Peter; Bumberger, Jan

2015-04-01

The aim of gaining a better understanding of ecosystems and the processes in nature accentuates the need for observing exactly these processes with a higher temporal and spatial resolution. In the field of environmental monitoring, an inexpensive and field applicable imaging technique to derive three-dimensional information about plants and vegetation would represent a decisive contribution to the understanding of the interactions and dynamics of ecosystems. This is particularly true for the monitoring of plant growth and the frequently mentioned lack of morphological information about the plants, e.g. plant height, vegetation canopy, leaf position or leaf arrangement. Therefore, an innovative and inexpensive light-field (plenoptic) camera, the Lytro LF, and a stereo vision system, based on two industrial cameras, were tested and evaluated as possible measurement tools for the given monitoring purpose. In this instance, the usage of a light field camera offers the promising opportunity of providing three-dimensional information without any additional requirements during the field measurements based on one single shot, which represents a substantial methodological improvement in the area of environmental research and monitoring. Since the Lytro LF was designed as a daily-life consumer camera, it does not support depth or distance estimation or rather an external triggering by default. Therefore, different technical modifications and a calibration routine had to be figured out during the preliminary study. As a result, the used light-field camera was proven suitable as a depth and distance measurement tool with a measuring range of approximately one meter. Consequently, this confirms the assumption that a light field camera holds the potential of being a promising measurement tool for environmental monitoring purposes, especially with regard to a low methodological effort in field. Within the framework of the Global Change Experimental Facility Project, founded by the Helmholtz Centre for Environmental Research, and its large-scaled field experiments to investigate the influence of the climate change on different forms of land utilization, both techniques were installed and evaluated in a long-term experiment on a pilot-scaled maize field in late 2014. Based on this, it was possible to show the growth of the plants in dependence of time, showing a good accordance to the measurements, which were carried out by hand on a weekly basis. In addition, the experiment has shown that the light-field vision approach is applicable for the monitoring of the crop growth under field conditions, although it is limited to close range applications. Since this work was intended as a proof of concept, further research is recommended, especially with respect to the automation and evaluation of data processing. Altogether, this study is addressed to researchers as an elementary groundwork to improve the usage of the introduced light field imaging technique for the monitoring of plant growth dynamics and the three-dimensional modeling of plants under field conditions.

Monitoring Kilauea Volcano Using Non-Telemetered Time-Lapse Camera Systems

NASA Astrophysics Data System (ADS)

Orr, T. R.; Hoblitt, R. P.

2006-12-01

Systematic visual observations are an essential component of monitoring volcanic activity. At the Hawaiian Volcano Observatory, the development and deployment of a new generation of high-resolution, non- telemetered, time-lapse camera systems provides periodic visual observations in inaccessible and hazardous environments. The camera systems combine a hand-held digital camera, programmable shutter-release, and other off-the-shelf components in a package that is inexpensive, easy to deploy, and ideal for situations in which the probability of equipment loss due to volcanic activity or theft is substantial. The camera systems have proven invaluable in correlating eruptive activity with deformation and seismic data streams. For example, in late 2005 and much of 2006, Pu`u `O`o, the active vent on Kilauea Volcano`s East Rift Zone, experienced 10--20-hour cycles of inflation and deflation that correlated with increases in seismic energy release. A time-lapse camera looking into a skylight above the main lava tube about 1 km south of the vent showed an increase in lava level---an indicator of increased lava flux---during periods of deflation, and a decrease in lava level during periods of inflation. A second time-lapse camera, with a broad view of the upper part of the active flow field, allowed us to correlate the same cyclic tilt and seismicity with lava breakouts from the tube. The breakouts were accompanied by rapid uplift and subsidence of shatter rings over the tube. The shatter rings---concentric rings of broken rock---rose and subsided by as much as 6 m in less than an hour during periods of varying flux. Time-lapse imagery also permits improved assessment of volcanic hazards, and is invaluable in illustrating the hazards to the public. In collaboration with Hawaii Volcanoes National Park, camera systems have been used to monitor the growth of lava deltas at the entry point of lava into the ocean to determine the potential for catastrophic collapse.

Utilization and viability of biologically-inspired algorithms in a dynamic multiagent camera surveillance system

NASA Astrophysics Data System (ADS)

Mundhenk, Terrell N.; Dhavale, Nitin; Marmol, Salvador; Calleja, Elizabeth; Navalpakkam, Vidhya; Bellman, Kirstie; Landauer, Chris; Arbib, Michael A.; Itti, Laurent

2003-10-01

In view of the growing complexity of computational tasks and their design, we propose that certain interactive systems may be better designed by utilizing computational strategies based on the study of the human brain. Compared with current engineering paradigms, brain theory offers the promise of improved self-organization and adaptation to the current environment, freeing the programmer from having to address those issues in a procedural manner when designing and implementing large-scale complex systems. To advance this hypothesis, we discus a multi-agent surveillance system where 12 agent CPUs each with its own camera, compete and cooperate to monitor a large room. To cope with the overload of image data streaming from 12 cameras, we take inspiration from the primate"s visual system, which allows the animal to operate a real-time selection of the few most conspicuous locations in visual input. This is accomplished by having each camera agent utilize the bottom-up, saliency-based visual attention algorithm of Itti and Koch (Vision Research 2000;40(10-12):1489-1506) to scan the scene for objects of interest. Real time operation is achieved using a distributed version that runs on a 16-CPU Beowulf cluster composed of the agent computers. The algorithm guides cameras to track and monitor salient objects based on maps of color, orientation, intensity, and motion. To spread camera view points or create cooperation in monitoring highly salient targets, camera agents bias each other by increasing or decreasing the weight of different feature vectors in other cameras, using mechanisms similar to excitation and suppression that have been documented in electrophysiology, psychophysics and imaging studies of low-level visual processing. In addition, if cameras need to compete for computing resources, allocation of computational time is weighed based upon the history of each camera. A camera agent that has a history of seeing more salient targets is more likely to obtain computational resources. The system demonstrates the viability of biologically inspired systems in a real time tracking. In future work we plan on implementing additional biological mechanisms for cooperative management of both the sensor and processing resources in this system that include top down biasing for target specificity as well as novelty and the activity of the tracked object in relation to sensitive features of the environment.

Human care system for heart-rate and human-movement trajectory in home and its application to detect mental disease

NASA Astrophysics Data System (ADS)

Hata, Yutaka; Kanazawa, Seigo; Endo, Maki; Tsuchiya, Naoki; Nakajima, Hiroshi

2012-06-01

This paper proposes a heart rate monitoring system for detecting autonomic nervous system by the heart rate variability using an air pressure sensor to diagnose mental disease. Moreover, we propose a human behavior monitoring system for detecting the human trajectory in home by an infrared camera. In day and night times, the human behavior monitoring system detects the human movement in home. The heart rate monitoring system detects the heart rate in bed in night time. The air pressure sensor consists of a rubber tube, cushion cover and pressure sensor, and it detects the heart rate by setting it to bed. It unconstraintly detects the RR-intervals; thereby the autonomic nervous system can be assessed. The autonomic nervous system analysis can examine the mental disease. While, the human behavior monitoring system obtains distance distribution image by an infrared camera. It classifies adult, child and the other object from distance distribution obtained by the camera, and records their trajectories. This behavior, i.e., trajectory in home, strongly corresponds to cognitive disorders. Thus, the total system can detect mental disease and cognitive disorders by uncontacted sensors to human body.

Towards real-time non contact spatial resolved oxygenation monitoring using a multi spectral filter array camera in various light conditions

NASA Astrophysics Data System (ADS)

Bauer, Jacob R.; van Beekum, Karlijn; Klaessens, John; Noordmans, Herke Jan; Boer, Christa; Hardeberg, Jon Y.; Verdaasdonk, Rudolf M.

2018-02-01

Non contact spatial resolved oxygenation measurements remain an open challenge in the biomedical field and non contact patient monitoring. Although point measurements are the clinical standard till this day, regional differences in the oxygenation will improve the quality and safety of care. Recent developments in spectral imaging resulted in spectral filter array cameras (SFA). These provide the means to acquire spatial spectral videos in real-time and allow a spatial approach to spectroscopy. In this study, the performance of a 25 channel near infrared SFA camera was studied to obtain spatial oxygenation maps of hands during an occlusion of the left upper arm in 7 healthy volunteers. For comparison a clinical oxygenation monitoring system, INVOS, was used as a reference. In case of the NIRS SFA camera, oxygenation curves were derived from 2-3 wavelength bands with a custom made fast analysis software using a basic algorithm. Dynamic oxygenation changes were determined with the NIR SFA camera and INVOS system at different regional locations of the occluded versus non-occluded hands and showed to be in good agreement. To increase the signal to noise ratio, algorithm and image acquisition were optimised. The measurement were robust to different illumination conditions with NIR light sources. This study shows that imaging of relative oxygenation changes over larger body areas is potentially possible in real time.

Mariner Venus-Mercury 1973 Project. Volume 1: Venus and Mercury 1 Encounters

NASA Technical Reports Server (NTRS)

1976-01-01

The primary mission report includes the Venus encounter and the first Mercury encounter. Plans and activities undertaken to successfully achieve the mission objectives are described. Operational activities are identified by mission operation system functions, providing a brief summary of each discipline. Spacecraft performance is summarized by subsystems.

Mariner 10 Venus encounter. [scientific objectives and instruments for flyby observations

NASA Technical Reports Server (NTRS)

Dunne, J. A.

1974-01-01

Review of the scientific objectives of the Mariner 10 mission with regard to observations of Venus during a flyby, and description of the equipment installed on the spacecraft to fulfill these objectives. A detailed description is given of the hardware modifications made to the payload specifically for the Venus sequence. In discussing the encounter operations, two spacecraft problems which significantly affected the Venus encounter sequence are cited - namely, a failure of the television optic heaters to come on shortly after launch, and the occurrence of a roll gyro oscillation.

DAVINCI: Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging

NASA Technical Reports Server (NTRS)

Glaze, Lori S.; Garvin, James B.; Robertson, Brent; Johnson, Natasha M.; Amato, Michael J.; Thompson, Jessica; Goodloe, Colby; Everette, Dave

2017-01-01

DAVINCI is one of five Discovery-class missions selected by NASA in October 2015 for Phase A studies. Launching in November 2021 and arriving at Venus in June of 2023, DAVINCI would be the first U.S. entry probe to target Venus atmosphere in 45 years. DAVINCI is designed to study the chemical and isotopic composition of a complete cross-section of Venus atmosphere at a level of detail that has not been possible on earlier missions and to image the surface at optical wavelengths and process-relevant scales.

Gravity field of Venus at constant altitude and comparison with earth

NASA Technical Reports Server (NTRS)

Bowin, C.; Abers, G.; Shure, L.

1985-01-01

The gravity field of Venus is characterized in gravity-anomaly and geoid-undulation maps produced by applying the harmonic-spline technique (Shure et al., 1982 and 1983; Parker and Shure, 1982) to Pioneer Venus Orbiter line-of-sight data. A positive correlation between Venusian topographic features and gravity anomalies is observed, in contrast to the noncorrelation seen on earth, and attributed to the thicker crust of Venus (70-80 vs 5-40 km for earth), crustal loading by recent volcanism, and possible regional elevation due to deep heating and thermal expansion.

Croconic acid - An absorber in the Venus clouds?

NASA Technical Reports Server (NTRS)

Hartley, Karen K.; Wolff, Andrew R.; Travis, Larry D.

1989-01-01

The absorbing species responsible for the UV cloud features and pale yellow hue of the Venus clouds is presently suggested to be the carbon monoxide-polymer croconic acid, which strongly absorbs in the blue and near-UV. Laboratory absorption-coefficient measurements of a dilute solution of croconic acid in sulfuric acid are used as the bases of cloud-scattering models; the Venus planetary albedo's observed behavior in the blue and near-UV are noted to be qualitatively reproduced. Attention is given to a plausible croconic acid-production mechanism for the Venus cloudtop region.

Theoretical interpretation of the Venus 1.05-micron CO2 band and the Venus 0.8189-micron H2O line.

NASA Technical Reports Server (NTRS)

Regas, J. L.; Giver, L. P.; Boese, R. W.; Miller, J. H.

1972-01-01

The synthetic-spectrum technique was used in the analysis. The synthetic spectra were constructed with a model which takes into account both isotropic scattering and the inhomogeneity in the Venus atmosphere. The Potter-Hansen correction factor was used to correct for anisotropic scattering. The synthetic spectra obtained are, therefore, the first which contain all the essential physics of line formation. The results confirm Potter's conclusion that the Venus cloud tops resemble terrestrial cirrus or stratus clouds in their scattering properties.

VLF emissions in the Venus foreshock - Comparison with terrestrial observations

NASA Technical Reports Server (NTRS)

Crawford, G. K.; Strangeway, R. J.; Russell, C. T.

1993-01-01

An examination is conducted of ELF/VLF emissions observed in the solar wind upstream of the Venus shock, for the 100 Hz-30 kHz range, using data from the Pioneer Venus Orbiter's electric field detector and magnetometer instruments. Detailed comparisons are made with terrestrial measurements for both the electron and ion foreshocks. The results obtained support the Crawford et al. (1990) identification of the Venus electron foreshock emissions as electron plasma oscillations, whose waves are generated in situ and act to isotropize the electron distributions.

Four Years of Venus Express Magnetic Field Observations: Variable Bow Shock Location and Other Features

NASA Astrophysics Data System (ADS)

Zhang, Tielong; Baumjohann, Wolfgang; Russell, C. T.

Since the Venus Express insertion into a highly elliptical polar orbit with a period of 24 h around the planet Venus, the magnetometer has operated continuously for about 4 years and obtained a wealth of data in the solar minimum at rather low altitude, which was not reached by earlier missions. In this paper, we review the magnetic field observations by Venus Express emphasizing on the variable bow shock location and other space environment features such as the magnetic barrier and the magnetotail.

The clouds of Venus. [physical and chemical properties

NASA Technical Reports Server (NTRS)

Young, A. T.

1975-01-01

The physical and chemical properties of the clouds of Venus are reviewed, with special emphasis on data that are related to cloud dynamics. None of the currently-popular interpretations of cloud phenomena on Venus is consistent with all the data. Either a considerable fraction of the observational evidence is faulty or has been misinterpreted, or the clouds of Venus are much more complex than the current simplistic models. Several lines of attack are suggested to resolve some of the contradictions. A sound understanding of the clouds appears to be several years in the future.

Venus lives!. [evidence for active volcanoes

NASA Technical Reports Server (NTRS)

Wood, Charles A.; Francis, Peter W.

1988-01-01

Observational evidence which supports the contention that Venus is a volcanically and tectonically active planet is discussed. It is argued that, although there are no observations to date that would prove that Venus has been volcanically active during the last decade, planetological studies presented evidence for youthful volcanic mountains on Venus: the surface of the northern quarter of Venus is considered to be younger than 1 Gy, and some units are likely to be much younger. Because of the small sizes of likely volcanic manifestations and the long intervals expected between eruptions, it is unlikely that any direct evidence of eruptions will be detected with existing and planned spacecraft. It is suggested that future studies of the dynamics and the chemical mixing of the Venusian atmosphere might supply an unequivocal evidence for active volcanism on this planet.

Studies of the atmosphere of Venus by means of spacecraft: Solved and unsolved problems

NASA Astrophysics Data System (ADS)

Moroz, V. I.

Many spacecraft were used for exploration of the atmosphere of Venus. Their list consists of 25 items, including fly-by missions, orbiters, descent and landing probes and even balloons. VENERA-4 (1967) was near the beginning of this list, providing the first time in situ experiments on other planet. It started a long sequence of successful Soviet Venera missions. However after the year 1985 there were no missions to Venus in Russia. It probably was a strategic error. Now several groups of scientists in other countries work on proposals for new missions to Venus. The goal of this paper is to present a brief review of already solved and still unsolved problems in the studies of the Venus' atmosphere and to possible future aims in this field.

First results of an Investigation of Sulfur Dioxide in the Ultraviolet from Pioneer Venus through Venus Express

NASA Astrophysics Data System (ADS)

McGouldrick, Kevin; Molaverdikhani, K.; Esposito, L. W.; Pankratz, C. K.

2010-10-01

The Laboratory for Atmospheric and Space Physics is carrying on a project to restore and preserve data products from several past missions for archival and use by the scientific community. This project includes the restoration of data from Mariner 6/7, Pioneer Venus, Voyager 1/2, and Galileo. Here, we present initial results of this project that involve Pioneer Venus Orbiter Ultraviolet Spectrometer (PVO UVS) data. Using the Discrete Ordinate Method for Radiative Transfer (DISORT), we generate a suite of models for the three free parameters in the upper atmosphere of Venus in which we are interested: sulfur dioxide abundance at 40mb, scale height of sulfur dioxide, and the typical radius of the upper haze particles (assumed to be composed of 84.5% sulfuric acid). We calculate best fits to our radiative transfer model results for multi-spectral images taken with PVO UVS, as well as the 'visible' channel (includes wavelengths from 290nm to about 1000nm) of the mapping mode of the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS-M-Vis) on the Venus Express spacecraft, currently orbiting Venus. This work is funded though the NASA Planetary Mission Data Analysis Program, NNH08ZDA001N.

Study and interpretation of the millimeter-wave spectrum of Venus

NASA Technical Reports Server (NTRS)

Fahd, Antoine K.; Steffes, Paul G.

1992-01-01

The effects of the Venus atmospheric constituents on its millimeter wavelength emission are investigated. Specifically, this research describes the methodology and the results of laboratory measurements which are used to calculate the opacity of some of the major absorbers in the Venus atmosphere. The pressure broadened absorption of gaseous SO2/CO2 and gaseous H2SO4/CO2 has been measured at millimeter wavelengths. We have also developed new formalisms for computing the absorptivities of these gases based on our laboratory work. The complex dielectric constant of liquid sulfuric acid has been measured and the expected opacity from the liquid sulfuric acid cloud layer found in the atmosphere of Venus has been evaluated. The partial pressure of gaseous H2SO4 has been measured which results in a more accurate estimate of the dissociation factor of H2SO4. A radiative transfer model has been developed in order to understand how each atmospheric constituent affects the millimeter wave emissions from Venus. Our results from the radiative transfer model are compared with recent observations of the micro-wave and millimeter wave emissions from Venus. Our main conclusion from this work is that gaseous H2SO4 is the most likely cause of the variation in the observed emission from Venus at 112 GHz.

Investigating circular patterns in linear polarization observations of Venus

NASA Astrophysics Data System (ADS)

Mahapatra, Gourav; Stam, Daphne; Rossi, Loic; Rodenhuis, Michiel; Snik, Frans

2017-04-01

ESA's Venus Express mission has revealed our neighbouring planet to be a highly dynamic world, with ever-changing cloud properties and structures, wind speeds that increase in time, and variable concentrations of atmospheric trace gases such as SO2. The SPICAV-IR instrument on Venus Express has provided us with close-up linear polarization data of sunlight reflected by Venus's clouds and hazes, that allows a characterisation of their composition and particle sizes. Here, we analyse linear polarization data of the planet at a distance, obtained with the Extreme Polarimeter (ExPo) on the William Herschel Telescope on La Palma. These spatially resolved, high-accuracy polarization observations of Venus show faint circular patterns centered on the sub-solar point that are absent in the flux observations. So far, careful analyses have ruled out instrumental effects which leaves us to wonder about atmospheric properties as the cause of the circular patterns. Using numerical simulations of the flux and polarization of sunlight that is reflected by Venus, we have investigated the relation between the observed patterns and several atmospheric properties, such as variations in particle sizes, composition, density and altitude. We discuss the plausibility of the possible causes in the view of the current knowledge of the composition and dynamical processes in Venus's atmosphere.

The Quasi-monochromatic ULF Wave Boundary in the Venusian Foreshock: Venus Express Observations

NASA Astrophysics Data System (ADS)

Shan, Lican; Mazelle, Christian; Meziane, Karim; Romanelli, Norberto; Ge, Yasong S.; Du, Aimin; Lu, Quanming; Zhang, Tielong

2018-01-01

The location of ultralow-frequency (ULF) quasi-monochromatic wave onset upstream of Venus bow shock is explored using Venus Express magnetic field data. We report the existence of a spatial foreshock boundary behind which ULF waves are present. We have found that the ULF wave boundary at Venus is sensitive to the interplanetary magnetic field (IMF) direction like the terrestrial one and appears well defined for a cone angle larger than 30°. In the Venusian foreshock, the inclination angle of the wave boundary with respect to the Sun-Venus direction increases with the IMF cone angle. We also found that for the IMF nominal direction (θBX = 36°) at Venus' orbit, the value of this inclination angle is 70°. Moreover, we have found that the inferred velocity of an ion traveling along the ULF boundary is in a qualitative agreement with a quasi-adiabatic reflection of a portion of the solar wind at the bow shock. For an IMF nominal direction at Venus, the inferred bulk speed of ions traveling along this boundary is 1.07 VSW, sufficiently enough to overcome the solar wind convection. This strongly suggests that the backstreaming ions upstream of the Venusian bow shock provide the main energy source for the ULF waves.

Crustal deformation: Earth vs Venus

NASA Technical Reports Server (NTRS)

Turcotte, D. L.

1989-01-01

It is timely to consider the possible tectonic regimes on Venus both in terms of what is known about Venus and in terms of deformation mechanisms operative on the earth. Plate tectonic phenomena dominate tectonics on the earth. Horizontal displacements are associated with the creation of new crust at ridges and destruction of crust at trenches. The presence of plate tectonics on Venus is debated, but there is certainly no evidence for the trenches associated with subduction on the earth. An essential question is what kind of tectonics can be expected if there is no plate tectonics on Venus. Mars and the Moon are reference examples. Volcanic constructs appear to play a dominant role on Mars but their role on Venus is not clear. On single plate planets and satellites, tectonic structures are often associated with thermal stresses. Cooling of a planet leads to thermal contraction and surface compressive features. Delamination has been propsed for Venus by several authors. Delamination is associated with the subduction of the mantle lithosphere and possibly the lower crust but not the upper crust. The surface manifestations of delamination are unclear. There is some evidence that delamination is occurring beneath the Transverse Ranges in California. Delamination will certainly lead to lithospheric thinning and is likely to lead to uplift and crustal thinning.

Characterization of the dynamics of the atmosphere of Venus with Doppler velocimetry

NASA Astrophysics Data System (ADS)

Machado, Pedro Miguel Borges do Canto Mota

Currently the study of the Venus' atmosphere grows as a theme of major interest among the astrophysics scientific community. The most significant aspect of the general circulation of the atmosphere of Venus is its retrograde super-rotation. A complete characterization of this dynamical phenomenon is crucial for understanding its driving mechanisms. This work participates in the international effort to characterize the atmospheric dynamics of this planet in coordination with orbiter missions, in particular with Venus Express. The objectives of this study are to investigate the nature of the processes governing the super-rotation of the atmosphere of Venus using ground-based observations, thereby complementing measurements by orbiter instruments. This thesis analyzes observations of Venus made with two different instruments and Doppler velocimetry techniques. The data analysis technique allowed an unambiguous characterization of the zonal wind latitudinal profile and its temporal variability, as well as an investigation of large-scale planetary waves signature and their role in the maintenance of the zonal super-rotation, and suggest that detection and investigation of large-scale planetary waves can be carried out with this technique.These studies complement the independent observations of the european space mission Venus Express, in particular as regards the study of atmospheric super-rotation, meridional flow and its variability. (Abstract shortened by ProQuest.).

Venus as a laboratory for studying planetary surface, interior, and atmospheric evolution

NASA Astrophysics Data System (ADS)

Smrekar, S. E.; Hensley, S.; Helbert, J.

2013-12-01

As Earth's twin, Venus offers a laboratory for understanding what makes our home planet unique in our solar system. The Decadal Survey points to the role of Venus in answering questions such as the supply of water and its role in atmospheric evolution, its availability to support life, and the role of geology and dynamics in controlling volatiles and climate. On Earth, the mechanism of plate tectonics drives the deformation and volcanism that allows volatiles to escape from the interior to the atmosphere and be recycled into the interior. Magellan revealed that Venus lacks plate tectonics. The number and distribution of impact craters lead to the idea Venus resurfaced very rapidly, and inspired numerous models of lithospheric foundering and episodic plate tectonics. However we have no evidence that Venus ever experienced a plate tectonic regime. How is surface deformation affected if no volatiles are recycled into the interior? Although Venus is considered a ';stagnant' lid planet (lacking plate motion) today, we have evidence for recent volcanism. The VIRTIS instrument on Venus Express mapped the southern hemisphere at 1.02 microns, revealing areas likely to be unweathered, recent volcanic flows. Additionally, numerous studies have shown that the crater population is consistent with ongoing, regional resurfacing. How does deformation and volcanism occur in the absence of plates? At what rate is the planet resurfacing and thus outgassing? Does lithospheric recycling occur with plate tectonics? In the 25 years since Magellan, the design of Synthetic Aperture Radar has advanced tremendously, allowing order of magnitude improvements in altimetry and imaging. With these advanced tools, we can explore Venus' past and current tectonic states. Tesserae are highly deformed plateaus, thought to be possible remnants of Venus' earlier tectonic state. How did they form? Are they low in silica, like Earth's continents, indicating the presence of abundant water? Does the plains volcanism cover an earlier tectonic surface, or perhaps cover ancient impact basins? Was there an abrupt transition in tectonic style, perhaps due to degassing of the crust or a more gradual shift? What is the nature of Venus' modern tectonics? Is the lithosphere still deforming? Is there recent or active volcanism? Is volcanism confined to hotspots, areas above mantle plumes? Has plains volcanism ceased? What are the implications for volatile history? These questions can be addressed via a combination of high resolution altimetry, imaging, and surface emissivity mapping.

The Venus Emissivity Mapper - gaining a global perspective on the surface composition of Venus

NASA Astrophysics Data System (ADS)

Helbert, Joern; Dyar, Melinda; Widemann, Thomas; Marcq, Emmanuel; Maturilli, Alessandro; Mueller, Nils; Kappel, David; Ferrari, Sabrina; D'Amore, Mario; Tsang, Constantine; Arnold, Gabriele; Smrekar, Suzanne; VEM Team

2017-10-01

The permanent cloud cover of Venus prohibits observations of the surface with traditional imaging techniques over much of the EM spectral range, leading to the false notion that information about the composition of Venus’ surface could only be derived from lander missions. However, harsh environmental conditions on the surface cause landed missions to be sole site, highly complex, and riskier than orbiting missions.It is now known that 5 transparency windows occur in the Venus atmosphere, ranging from 0.86 µm to 1.18 µm. Recent advances in high temperature laboratory spectroscopy at the PSL at DLR these windows are highly diagnostic for surface mineralogy. Mapping of the southern hemisphere of Venus with VIRTIS on VEX in the 1.02 µm band was a proof-of-concept for an orbital remote sensing approach to surface composition and weathering studies[1-3]. The Venus Emissivity Mapper [4] proposed for the NASA’s Venus Origins Explorer (VOX) and the ESA EnVision proposal builds on these recent advances. It is the first flight instrument specially designed with a sole focus on mapping the surface of Venus using the narrow atmospheric windows around 1 µm. Operating in situ from Venus orbit, VEM will provide a global map of surface composition as well as redox state of the surface, providing a comprehensive picture of surface-atmosphere interaction and support for landing site selection. Continuous observation of the thermal emission of the Venus will provide tight constraints on the current day volcanic activity[5]. This is complemented by measurements of atmospheric water vapor abundance as well as cloud microphysics and dynamics. These data will allow for accurate correction of atmospheric interference on the surface measurements, which provide highly valuable science on their own. A mission combining VEM with a high-resolution radar mapper such as VOX or EnVision in a low circular orbit will provide key insights into the divergent evolution of Venus.1. Smrekar, S.E., et al., Science, 2010. 328(5978): p. 605-8.2. Helbert, J., et al., GRL, 2008. 35(11).3. Mueller, N., et al., JGR, 2008. 113.4. Helbert, J., et al. 2016. San Diego, CA: SPIE.5. Mueller, N.T., et al., JGR, 2017.

Coordinated Hubble Space Telescope and Venus Express Observations of Venus' upper cloud deck

NASA Astrophysics Data System (ADS)

Jessup, Kandis Lea; Marcq, Emmanuel; Mills, Franklin; Mahieux, Arnaud; Limaye, Sanjay; Wilson, Colin; Allen, Mark; Bertaux, Jean-Loup; Markiewicz, Wojciech; Roman, Tony; Vandaele, Ann-Carine; Wilquet, Valerie; Yung, Yuk

2015-09-01

Hubble Space Telescope Imaging Spectrograph (HST/STIS) UV observations of Venus' upper cloud tops were obtained between 20N and 40S latitude on December 28, 2010; January 22, 2011 and January 27, 2011 in coordination with the Venus Express (VEx) mission. The high spectral (0.27 nm) and spatial (40-60 km/pixel) resolution HST/STIS data provide the first direct and simultaneous record of the latitude and local time distribution of Venus' 70-80 km SO and SO2 (SOx) gas density on Venus' morning quadrant. These data were obtained simultaneously with (a) VEx/SOIR occultation and/or ground-based James Clerk Maxwell Telescope sub-mm observations that record respectively, Venus' near-terminator SO2 and dayside SOx vertical profiles between ∼75 and 100 km; and (b) 0.36 μm VEx/VMC images of Venus' cloud-tops. Updating the (Marcq, E. et al. [2011]. Icarus 211, 58-69) radiative transfer model SO2 gas column densities of ∼2-10 μm-atm and ∼0.4-1.8 μm-atm are retrieved from the December 2010 and January 2011 HST observations, respectively on Venus' dayside (i.e., at solar zenith angles (SZA) < 60°); SO gas column densities of 0.1-0.11 μm-atm, 0.03-0.31 μm-atm and 0.01-0.13 μm-atm are also retrieved from the respective December 28, 2010, January 22, 2011 and January 27, 2011 HST observations. A decline in the observed low-latitude 0.24 and 0.36 μm cloud top brightness paralleled the declining SOx gas densities. On December 28, 2010 SO2 VMR values ∼280-290 ppb are retrieved between 74 and 81 km from the HST and SOIR data obtained near Venus' morning terminator (at SZAs equal to 70° and 90°, respectively); these values are 10× higher than the HST-retrieved January 2011 near terminator values. Thus, the cloud top SO2 gas abundance declined at all local times between the three HST observing dates. On all dates the average dayside SO2/SO ratio inferred from HST between 70 and 80 km is higher than that inferred from the sub-mm the JCMT data above 84 km confirming that SOx photolysis is more efficient at higher altitudes. The direct correlation of the SOx gases provides the first clear evidence that SOx photolysis is not the only source for Venus' 70-80 km sulfur reservoir. The cloud top SO2 gas density is dependent in part on the vertical transport of the gas from the lower atmosphere; and the 0.24 μm cloud top brightness levels are linked to the density of the sub-micron haze. Thus, the new results may suggest a correlation between Venus' cloud-top sub-micron haze density and the vertical transport rate. These new results must be considered in models designed to simulate and explore the relationship between Venus' sulfur chemistry cycle, H2SO4 cloud formation rate and climate evolution. Additionally, we present the first photochemical model that uniquely tracks the transition of the SO2 atmosphere from steady to non-steady state with increasing SZA, as function of altitude within Venus' mesosphere, showing the photochemical and dynamical basis for the factor of ∼2 enhancements in the SOx gas densities observed by HST near the terminator above that observed at smaller SZA. These results must also be considered when modeling the long-term evolution of Venus' atmospheric chemistry and dynamics.

Improving the color fidelity of cameras for advanced television systems

NASA Astrophysics Data System (ADS)

Kollarits, Richard V.; Gibbon, David C.

1992-08-01

In this paper we compare the accuracy of the color information obtained from television cameras using three and five wavelength bands. This comparison is based on real digital camera data. The cameras are treated as colorimeters whose characteristics are not linked to that of the display. The color matrices for both cameras were obtained by identical optimization procedures that minimized the color error The color error for the five band camera is 2. 5 times smaller than that obtained from the three band camera. Visual comparison of color matches on a characterized color monitor indicate that the five band camera is capable of color measurements that produce no significant visual error on the display. Because the outputs from the five band camera are reduced to the normal three channels conventionally used for display there need be no increase in signal handling complexity outside the camera. Likewise it is possible to construct a five band camera using only three sensors as in conventional cameras. The principal drawback of the five band camera is the reduction in effective camera sensitivity by about 3/4 of an I stop. 1.

Using digital time-lapse cameras to monitor species-specific understorey and overstorey phenology in support of wildlife habitat assessment.

PubMed

Bater, Christopher W; Coops, Nicholas C; Wulder, Michael A; Hilker, Thomas; Nielsen, Scott E; McDermid, Greg; Stenhouse, Gordon B

2011-09-01

Critical to habitat management is the understanding of not only the location of animal food resources, but also the timing of their availability. Grizzly bear (Ursus arctos) diets, for example, shift seasonally as different vegetation species enter key phenological phases. In this paper, we describe the use of a network of seven ground-based digital camera systems to monitor understorey and overstorey vegetation within species-specific regions of interest. Established across an elevation gradient in western Alberta, Canada, the cameras collected true-colour (RGB) images daily from 13 April 2009 to 27 October 2009. Fourth-order polynomials were fit to an RGB-derived index, which was then compared to field-based observations of phenological phases. Using linear regression to statistically relate the camera and field data, results indicated that 61% (r (2) = 0.61, df = 1, F = 14.3, p = 0.0043) of the variance observed in the field phenological phase data is captured by the cameras for the start of the growing season and 72% (r (2) = 0.72, df = 1, F = 23.09, p = 0.0009) of the variance in length of growing season. Based on the linear regression models, the mean absolute differences in residuals between predicted and observed start of growing season and length of growing season were 4 and 6 days, respectively. This work extends upon previous research by demonstrating that specific understorey and overstorey species can be targeted for phenological monitoring in a forested environment, using readily available digital camera technology and RGB-based vegetation indices.

Studies of radiative transfer in planetary atmospheres

NASA Technical Reports Server (NTRS)

Irvine, W. M.; Schloerb, F. P.

1984-01-01

Progress is reported in modeling cometary emission in the 18-cm OH transition with specific application and predictions for Comet Halley. Radiative transfer is also being studied in rough and porous media. The kinematics of the cold, dark interstellar cloud Li34N were examined, and CO monitoring of Venus and Mars continues. Analysis of 3.4 mm maps of the lunar surface shows thermal anomalies associated with such surface features as the Crater Copernicus, Mare Imbrium, Mare Nubium, Mare Serenitatis, and Mare Tranquillatis.

Potential and Limitations of Low-Cost Unmanned Aerial Systems for Monitoring Altitudinal Vegetation Phenology in the Tropics

NASA Astrophysics Data System (ADS)

Silva, T. S. F.; Torres, R. S.; Morellato, P.

2017-12-01

Vegetation phenology is a key component of ecosystem function and biogeochemical cycling, and highly susceptible to climatic change. Phenological knowledge in the tropics is limited by lack of monitoring, traditionally done by laborious direct observation. Ground-based digital cameras can automate daily observations, but also offer limited spatial coverage. Imaging by low-cost Unmanned Aerial Systems (UAS) combines the fine resolution of ground-based methods with and unprecedented capability for spatial coverage, but challenges remain in producing color-consistent multitemporal images. We evaluated the applicability of multitemporal UAS imaging to monitor phenology in tropical altitudinal grasslands and forests, answering: 1) Can very-high resolution aerial photography from conventional digital cameras be used to reliably monitor vegetative and reproductive phenology? 2) How is UAS monitoring affected by changes in illumination and by sensor physical limitations? We flew imaging missions monthly from Feb-16 to Feb-17, using a UAS equipped with an RGB Canon SX260 camera. Flights were carried between 10am and 4pm, at 120-150m a.g.l., yielding 5-10cm spatial resolution. To compensate illumination changes caused by time of day, season and cloud cover, calibration was attempted using reference targets and empirical models, as well as color space transformations. For vegetative phenological monitoring, multitemporal response was severely affected by changes in illumination conditions, strongly confounding the phenological signal. These variations could not be adequately corrected through calibration due to sensor limitations. For reproductive phenology, the very-high resolution of the acquired imagery allowed discrimination of individual reproductive structures for some species, and its stark colorimetric differences to vegetative structures allowed detection of the reproductive timing on the HSV color space, despite illumination effects. We conclude that reliable vegetative phenology monitoring may exceed the capabilities of consumer cameras, but reproductive phenology can be successfully monitored for species with conspicuous reproductive structures. Further research is being conducted to improve calibration methods and information extraction through machine learning.

STS-70 Post Flight Presentation

NASA Technical Reports Server (NTRS)

Peterson, Glen (Editor)

1995-01-01

In this post-flight overview, the flight crew of the STS-70 mission, Tom Henricks (Cmdr.), Kevin Kregel (Pilot), Major Nancy Currie (MS), Dr. Mary Ellen Weber (MS), and Dr. Don Thomas (MS), discuss their mission and accompanying experiments. Pre-flight, launch, and orbital footage is followed by the in-orbit deployment of the Tracking and Data Relay Satellite (TDRS) and a discussion of the following spaceborne experiments: a microgravity bioreactor experiment to grow 3D body-like tissue; pregnant rat muscular changes in microgravity; embryonic development in microgravity; Shuttle Amateur Radio Experiment (SAREX); terrain surface imagery using the HERCULES camera; and a range of other physiological tests, including an eye and vision test. Views of Earth include: tropical storm Chantal; the Nile River and Red Sea; lightning over Brazil. A three planet view (Earth, Mars, and Venus) was taken right before sunrise. The end footage shows shuttle pre-landing checkout, entry, and landing, along with a slide presentation of the flight.

Rapid-cadence optical monitoring for short-period variability of ɛ Aurigae

NASA Astrophysics Data System (ADS)

Billings, Gary

2013-07-01

ɛ Aurigae was observed with CCD cameras and 35 mm SLR camera lenses, at rapid cadence (>1/minute), for long runs (up to 11 hours), on multiple occasions during 2009 - 2011, to monitor for variability of the system at scales of minutes to hours. The lens and camera were changed during the period to improve results, finalizing on a 135 mm focal length Canon f/2 lens (at f/2.8), an ND8 neutral density filter, a Johnson V filter, and an SBIG ST-8XME camera (Kodak KAF-1603ME microlensed chip). Differential photometry was attempted, but because of the large separation between the variable and comparison star (η Aur), noise caused by transient extinction variations was not consistently eliminated. The lowest-noise time series for searching for short-period variability proved to be the extinction-corrected instrumental magnitude of ɛ Aur obtained on "photometric nights", with η Aur used to determine and monitor the extinction coefficient for the night. No flares or short-period variations of ɛ Aur were detected by visual inspection of the light curves from observing runs with noise levels as low as 0.008 magnitudes rms.

Active landslide monitoring using remote sensing data, GPS measurements and cameras on board UAV

NASA Astrophysics Data System (ADS)

Nikolakopoulos, Konstantinos G.; Kavoura, Katerina; Depountis, Nikolaos; Argyropoulos, Nikolaos; Koukouvelas, Ioannis; Sabatakakis, Nikolaos

2015-10-01

An active landslide can be monitored using many different methods: Classical geotechnical measurements like inclinometer, topographical survey measurements with total stations or GPS and photogrammetric techniques using airphotos or high resolution satellite images. As the cost of the aerial photo campaign and the acquisition of very high resolution satellite data is quite expensive the use of cameras on board UAV could be an identical solution. Small UAVs (Unmanned Aerial Vehicles) have started their development as expensive toys but they currently became a very valuable tool in remote sensing monitoring of small areas. The purpose of this work is to demonstrate a cheap but effective solution for an active landslide monitoring. We present the first experimental results of the synergistic use of UAV, GPS measurements and remote sensing data. A six-rotor aircraft with a total weight of 6 kg carrying two small cameras has been used. Very accurate digital airphotos, high accuracy DSM, DGPS measurements and the data captured from the UAV are combined and the results are presented in the current study.

Meeting Venus

NASA Astrophysics Data System (ADS)

Sterken, Christiaan; Aspaas, Per Pippin

2013-06-01

On 2-3 June 2012, the University of Tromsoe hosted a conference about the cultural and scientific history of the transits of Venus. The conference took place in Tromsoe for two very specific reasons. First and foremost, the last transit of Venus of this century lent itself to be observed on the disc of the Midnight Sun in this part of Europe during the night of 5 to 6 June 2012. Second, several Venus transit expeditions in this region were central in the global enterprise of measuring the scale of the solar system in the eighteenth century. The site of the conference was the Nordnorsk Vitensenter (Science Centre of Northern Norway), which is located at the campus of the University of Tromsoe. After the conference, participants were invited to either stay in Tromsoe until the midnight of 5-6 June, or take part in a Venus transit voyage in Finnmark, during which the historical sites Vardoe, Hammerfest, and the North Cape were to be visited. The post-conference program culminated with the participants observing the transit of Venus in or near Tromsoe, Vardoe and even from a plane near Alta. These Proceedings contain a selection of the lectures delivered on 2-3 June 2012, and also a narrative description of the transit viewing from Tromsoe, Vardoe and Alta. The title of the book, Meeting Venus, refers the title of a play by the Hungarian film director, screenwriter and opera director Istvan Szabo (1938-). The autobiographical movie Meeting Venus (1991) directed by him is based on his experience directing Tannhauser at the Paris Opera in 1984. The movie brings the story of an imaginary international opera company that encounters a never ending series of difficulties and pitfalls that symbolise the challenges of any multicultural and international endeavour. As is evident from the many papers presented in this book, Meeting Venus not only contains the epic tales of the transits of the seventeenth, eighteenth and nineteenth centuries, it also covers the conference participants' encounter with "Venus on the Sun" in historical archives as well as face-to-face at several locations in the Troms and Finnmark counties.

Hot climate inhibits volcanism on Venus: Constraints from rock deformation experiments and argon isotope geochemistry

NASA Astrophysics Data System (ADS)

Mikhail, Sami; Heap, Michael J.

2017-07-01

The disparate evolution of sibling planets Earth and Venus has left them markedly different. Venus' hot (460 °C) surface is dry and has a hypsometry with a very low standard deviation, whereas Earth's average temperature is 4 °C and the surface is wet and has a pronounced bimodal hypsometry. Counterintuitively, despite the hot Venusian climate, the rate of intraplate volcano formation is an order of magnitude lower than that of Earth. Here we compile and analyse rock deformation and atmospheric argon isotope data to offer an explanation for the relative contrast in volcanic flux between Earth and Venus. By collating high-temperature, high-pressure rock deformation data for basalt, we provide a failure mechanism map to assess the depth of the brittle-ductile transition (BDT). These data suggest that the Venusian BDT likely exists between 2 and 12 km depth (for a range of thermal gradients), in stark contrast to the BDT for Earth, which we find to be at a depth of ∼25-27 km using the same method. The implications for planetary evolution are twofold. First, downflexing and sagging will result in the sinking of high-relief structures, due to the low flexural rigidity of the predominantly ductile Venusian crust, offering an explanation for the curious coronae features on the Venusian surface. Second, magma delivery to the surface-the most efficient mechanism for which is flow along fractures (dykes; i.e., brittle deformation)-will be inhibited on Venus. Instead, we infer that magmas must stall and pond in the ductile Venusian crust. If true, a greater proportion of magmatism on Venus should result in intrusion rather than extrusion, relative to Earth. This predicted lower volcanic flux on Venus, relative to Earth, is supported by atmospheric argon isotope data: we argue here that the anomalously unradiogenic present-day atmospheric 40Ar/36Ar ratio for Venus (compared with Earth) must reflect major differences in 40Ar degassing, primarily driven by volcanism. Indeed, these argon data suggest that the volcanic flux on Venus has been three times lower than that on Earth over its 4.56 billion year history. We conclude that Venus' hot climate inhibits volcanism.

SAEVe: A Long Duration Small Sat Class Venus Lander - Seismic and Atmospheric Exploration of Venus

NASA Technical Reports Server (NTRS)

Kremic, Tibor; Ghail, Richard; Gilmore, Martha; Hunter, Gary; Kiefer, Walter; Limaye, Sanjay; Pauken, Michael; Tolbert, Carol; Wilson, Colin

2017-01-01

NASA's science mission directorate has put increasing emphasis on innovative, smaller, and lower cost missions to achieve their science objectives. One example of this was the recent call by the Planetary Science Division for cube and small satellite concepts expected to cost $100M or less, not including launch and weighing less than 180kg. Over 100 proposals were submitted suggesting that indeed this is a size of mission worthy of being considered in future planning. Nineteen missions were selected for study, one being a long-lived Venus mission called SAEVe, for Seismic and Atmospheric Exploration of Venus. The science objectives and relevance of SAEVe include: Is Venus seismically active? What can we learn about its crust (thickness and composition) and its interior (lithosphere, mantle, and core)? What can be learned about its evolutionary history or about the planet / atmosphere interactions? SAEVe begins to address these science questions with simple, but capable, instrumented probes that can survive on the surface of Venus and take temporal measurements over months something never attempted before. The data returned will further our understanding of the solar system and Earth, and aid in meeting the NASA Science Plan goal to ascertain the content, origin, and evolution of the solar system and the chemical and physical processes in our solar system. SAEVe is delivered to Venus as a ride-along on another mission to Venus. Its two small probes are placed into the Venus atmosphere via a single Stardust-like entry capsule, are ejected at different times, free fall, and decelerate in the thickening atmosphere to touchdown under 8 m/s2 or less. The probes will begin taking measurements and transmitting important parameters at or near the surface and will focus on measurements like seismic activity, heat flux, wind speed and direction, basic chemical abundances, temperature, and pressure. At preset intervals, the probes acquire the science measurements and beam the data to the orbiting host spacecraft. SAEVe will serve as a highly capable precursor and pave the way for larger and more complex lander missions to explore Venus.

Image quality analysis of a color LCD as well as a monochrome LCD using a Foveon color CMOS camera

NASA Astrophysics Data System (ADS)

Dallas, William J.; Roehrig, Hans; Krupinski, Elizabeth A.

2007-09-01

We have combined a CMOS color camera with special software to compose a multi-functional image-quality analysis instrument. It functions as a colorimeter as well as measuring modulation transfer functions (MTF) and noise power spectra (NPS). It is presently being expanded to examine fixed-pattern noise and temporal noise. The CMOS camera has 9 μm square pixels and a pixel matrix of 2268 x 1512 x 3. The camera uses a sensor that has co-located pixels for all three primary colors. We have imaged sections of both a color and a monochrome LCD monitor onto the camera sensor with LCD-pixel-size to camera-pixel-size ratios of both 12:1 and 17.6:1. When used as an imaging colorimeter, each camera pixel is calibrated to provide CIE color coordinates and tristimulus values. This capability permits the camera to simultaneously determine chromaticity in different locations on the LCD display. After the color calibration with a CS-200 colorimeter the color coordinates of the display's primaries determined from the camera's luminance response are very close to those found from the CS-200. Only the color coordinates of the display's white point were in error. For calculating the MTF a vertical or horizontal line is displayed on the monitor. The captured image is color-matrix preprocessed, Fourier transformed then post-processed. For NPS, a uniform image is displayed on the monitor. Again, the image is pre-processed, transformed and processed. Our measurements show that the horizontal MTF's of both displays have a larger negative slope than that of the vertical MTF's. This behavior indicates that the horizontal MTF's are poorer than the vertical MTF's. However the modulations at the Nyquist frequency seem lower for the color LCD than for the monochrome LCD. The spatial noise of the color display in both directions is larger than that of the monochrome display. Attempts were also made to analyze the total noise in terms of spatial and temporal noise by applying subtractions of images taken at exactly the same exposure. Temporal noise seems to be significantly lower than spatial noise.

Helium on Venus - Implications for uranium and thorium

NASA Technical Reports Server (NTRS)

Prather, M. J.; Mcelroy, M. B.

1983-01-01

Helium is removed at an average rate of 10 to the 6th atoms per square centimeter per second from Venus's atmosphere by the solar wind following ionization above the plasmapause. The surface source of helium-4 on Venus is similar to that on earth, suggesting comparable abundances of crustal uranium and thorium.

Venus in Violet and Near Infrared Light

NASA Image and Video Library

1996-02-01

These images of the Venus clouds were taken by NASA Galileo Solid State Imaging System February 13,1990, at a range of about 1 million miles. The smallest detail visible is about 20 miles. They show the state of the clouds near the top of Venus cloud. http://photojournal.jpl.nasa.gov/catalog/PIA00071

Nightside temperature measurements at 95 km from OH nightglow in the Venus atmosphere

NASA Astrophysics Data System (ADS)

Migliorini, A.; Snels, M.; Gérard, J.-C.; Soret, L.; Piccioni, G.; Drossart, P.

2017-09-01

Temperature estimations at an altitude of about 95 km on the night side of Venus are provided. They are derived from hydroxyl nightglow emissions, observed in the infrared spectral range at 2.7-3.5 micron, using the Visible and Infrared Thermal Imaging Spectrometer on board Venus Express.

Pioneer Venus: Report of a study by the Science Steering Group, June 1972. [concerning 1976, 77, 78 and 80 missions

NASA Technical Reports Server (NTRS)

1974-01-01

The 1976/77 multiple probe mission of the Pioneer Venus spacecraft is discussed, along with the 1978 and 1980 missions. Various questions about Venus are answered; velocities and temperatures expected in the atmosphere, atmospheric chemistry, magnetic measurements, and model atmospheres are included.

A statistical study of ionopause perturbation and associated boundary wave formation at Venus.

NASA Astrophysics Data System (ADS)

Chong, G. S.; Pope, S. A.; Walker, S. N.; Zhang, T.; Balikhin, M. A.

2017-12-01

In contrast to Earth, Venus does not possess an intrinsic magnetic field. Hence the interaction between solar wind and Venus is significantly different when compared to Earth, even though these two planets were once considered similar. Within the induced magnetosphere and ionosphere of Venus, previous studies have shown the existence of ionospheric boundary waves. These structures may play an important role in the atmospheric evolution of Venus. By using Venus Express data, the crossings of the ionopause boundary are determined based on the observations of photoelectrons during 2011. Pulses of dropouts in the electron energy spectrometer were observed in 92 events, which suggests potential perturbations of the boundary. Minimum variance analysis of the 1Hz magnetic field data for the perturbations is conducted and used to confirm the occurrence of the boundary waves. Statistical analysis shows that they were propagating mainly in the ±VSO-Y direction in the polar north terminator region. The generation mechanisms of boundary waves and their evolution into the potential nonlinear regime are discussed and analysed.

The Soviet maps of Venus

NASA Astrophysics Data System (ADS)

Robertson, D. F.

1990-02-01

The USSR began mapping parts of Venus almost six years ago and have published a series of scientific results, reaching a few limited conclusions about Venus. While based on the traditional second generation Venera orbiter design, Veneras 15 and 16 carried Polyus-V sidelooking synthetic-aperture radars which used the orbiter's motion over Venus to 'synthesize' an antenna of far larger size than could practically be carried to the planet. The resolution and coverage achieved is better than one kilometer over most of the surface compared with one tenth of a kilometer partial cover expected from the Venus Radar Mapper. The radar data will take years to analyze completely, but initial results have been released and the Soviet Union has compiled an atlas of radar images. Cartographers named two craters after American astronauts Judith Resnik and Sharon Christa McAuliffe. One of the conclusions is that Venus is not a 'single plate' planet, like the earth's moon or Mercury; its crust is distinctly broken into individual blocks with independent movements. It appears that extensive volcanism is a universal factor in the evolution of planets in the inner solar system.

Radially fractured domes: A comparison of Venus and the Earth

NASA Technical Reports Server (NTRS)

Janes, Daniel M.; Squyres, Steven W.

1993-01-01

Radially fractured domes are large, tectonic and topographic features discovered on the surface of Venus by the Magellan spacecraft. They are thought to be due to uplift over mantle diapirism, and to date are known to occur only on Venus. Since Venus and the Earth are grossly similar in size, composition and structure, we seek to understand why these features have not been seen on the Earth. We model the uplift and fracturing over a mantle diapir as functions of lithospheric thickness and diapir size and depth. We find that lithospheres of the same thickness on the Earth and Venus should respond similarly to the same sized diapir, and that radially fractured domes should form most readily in thin oceanic lithospheres on Earth if diapiric activity is similar on the two planets. However, our current knowledge of the Earth's oceanic floors is insufficient to confirm or deny the presence of radially fractured domes. We compute the expected dimensions for these features on the Earth and suggest a search for them to determine whether mantle diapirism operates similarly on the Earth and Venus.

Investigating the Origin and Evolution of Venus with In Situ Mass Spectrometry

NASA Technical Reports Server (NTRS)

Trainer, M. G.; Mahaffy, P. R.; Brinckerhoff, W. B.; Johnson, N. M.; Glaze, L. S.

2014-01-01

The exploration of Venus continues to be a top priority of planetary science. The Planetary Decadal Survey goals for inner-planet exploration seek to discern the origin and diversity of terrestrial planets, understand how the evolution of terrestrial planets relates to the evolution of life, and explore the processes that control climate on Earth-like planets [1]. These goals can only be realized through continued and extensive exploration of Venus, the most mysterious of the terrestrial planets, remarkably different from the Earth despite the gross similarities between these twin planets. It is unknown if this apparent divergence was intrinsic, programmed during accretion from distinct nebular reservoirs, or a consequence of either measured or catastrophic processes during planetary evolution. Even if the atmosphere of Venus is a more recent development, its relationship to the resurfacing of the planets enigmatic surface is not well understood. Resolving such uncertainties directly addresses the hypothesis of a more clement, possibly water-rich era in Venus past as well as whether Earth could become more Venus-like in the future.

Investigating the Origin and Evolution of Venus with In Situ Mass Spectrometry

NASA Technical Reports Server (NTRS)

Trainer, M. G.; Mahaffy, P. R.; Brinckerhoff, W. B.; Johnson, N. M.; Glaze, L. S.

2015-01-01

The exploration of Venus continues to be a top priority of planetary science. The Planetary Decadal Survey goals for inner-planet exploration seek to discern the origin and diversity of terrestrial planets, understand how the evolution of terrestrial planets relates to the evolution of life, and explore the processes that control climate on Earth-like planets. These goals can only be realized through continued and extensive exploration of Venus, the most mysterious of the terrestrial planets, remarkably different from the Earth despite the gross similarities between these "twin planets". It is unknown if this apparent divergence was intrinsic, programmed during accretion from distinct nebular reservoirs, or a consequence of either measured or catastrophic processes during planetary evolution. Even if the atmosphere of Venus is a more "recent" development, its relationship to the resurfacing of the planet's enigmatic surface is not well understood. Resolving such uncertainties directly addresses the hypothesis of a more clement, possibly water-rich era in Venus' past as well as whether Earth could become more Venus-like in the future.

Incorporating Planetary-Scale Waves Into the VTGCM: Understanding the Waves Impact on the Upper Atmosphere of Venus.

NASA Technical Reports Server (NTRS)

Brecht, A. S.; Bougher, S. W.; Shields, D.; Liu, H.

2017-01-01

Venus has proven to have a very dynamic upper atmosphere. The upper atmosphere of Venus has been observed for many decades by multiple means of observation (e.g. ground-based, orbiters, probes, fly-by missions going to other planets). As of late, the European Space Agency Venus Express (VEX) orbiter has been a main observer of the Venusian atmosphere. Specifically, observations of Venus' O2 IR nightglow emission have been presented to show its variability. Nightglow emission is directly connected to Venus' circulation and is utilized as a tracer for the atmospheric global wind system. More recent observations are adding and augmenting temperature and density (e.g. CO, CO2, SO2) datasets. These additional datasets provide a means to begin analyzing the variability and study the potential drivers of the variability. A commonly discussed driver of variability is wave deposition. Evidence of waves has been observed, but these waves have not been completely analyzed to understand how and where they are important. A way to interpret the observations and test potential drivers is by utilizing numerical models.

[Comment on “Is Venus alive?”

NASA Astrophysics Data System (ADS)

Scarf, Frederick

The June 3, 1986 issue of Eos contains a Forum by Harry Taylor (National Aeronautics and Space Administration Goddard Space Flight Laboratory, Greenbelt, Md.) with a report on his latest speculations regarding Venus lightning and on his interpretation of certain measurements from the plasma wave investigation on the Pioneer Venus Orbiter. The same views have also been announced as recent discoveries by Taylor and an associate in interviews in Science News (April 5, 1986) and in New Scientist (May 15, 1986). In fact, many of the statements and interpretations in Taylor's letter (and in the interviews) are demonstrably wrong, and I want to correct the record for Eos readers.Taylor's discussion refers to a number of Pioneer Venus publications that appeared in various journals between 1979 and 1986. In these papers, my colleagues and I identified as whistler mode plasma waves certain low-frequency impulses detected with an electric antenna at low altitudes during the Venus night. These Venus noise bursts have all the characteristics of whistlers from lightning, and this connection was discussed in all of the published papers.

Greenhouse models of Venus' high surface temperature, as constrained by Pioneer Venus measurements

NASA Technical Reports Server (NTRS)

Pollack, J. B.; Toon, O. B.; Boese, R.

1980-01-01

Recent measurements conducted from the Pioneer Venus probes and orbiter have provided a significantly improved definition of the solar net flux profile, the gaseous composition, temperature structure, and cloud properties of Venus' lower atmosphere. Using these data, we have carried out a series of one-dimensional radiative-convective equilibrium calculations to determine the viability of the greenhouse model of Venus' high surface temperature and to assess the chief contributors to the greenhouse effect. New sources of infrared opacity include the permitted transitions of SO2, CO, and HCl as well as opacity due to several pressure-induced transitions of CO2. We find that the observed surface temperature and lapse rate structure of the lower atmosphere can be reproduced quite closely with a greenhouse model that contains the water vapor abundance reported by the Venera spectrophotometer experiment. Thus the greenhouse effect can account for essentially all of Venus' high surface temperature. The prime sources of infrared opacity are, in order of importance, CO2, H2O, cloud particles, and SO2, with CO and HCl playing very minor roles.

Investigating the Origin and Evolution of Venus with in Situ Mass Spectrometry

NASA Technical Reports Server (NTRS)

Trainer, M. G.; Mahaffy, P. R.; Brinckerhoff, W. B.; Johnson, N. M.; Glaze, L. S.

2016-01-01

The exploration of Venus continues to be a top priority of planetary science. The Planetary Decadal Survey goals for inner-planet exploration seek to discern the origin and diversity of terrestrial planets, understand how the evolution of terrestrial planets relates to the evolution of life, and explore the processes that control climate on Earth-like planets. These goals can only be realized through continued and extensive exploration of Venus, the most mysterious of the terrestrial planets, remarkably different from the Earth despite the gross similarities between these "twin planets". It is unknown if this apparent divergence was intrinsic, programmed during accretion from distinct nebular reservoirs, or a consequence of either measured or catastrophic processes during planetary evolution. Even if the atmosphere of Venus is a more "recent" development, its relationship to the resurfacing of the planet's enigmatic surface is not well understood. Resolving such uncertainties directly addresses the hypothesis of a more clement, possibly water-rich era in Venus' past as well as whether Earth could become more Venus-like in the future.

An improved camera trap for amphibians, reptiles, small mammals, and large invertebrates

PubMed Central

2017-01-01

Camera traps are valuable sampling tools commonly used to inventory and monitor wildlife communities but are challenged to reliably sample small animals. We introduce a novel active camera trap system enabling the reliable and efficient use of wildlife cameras for sampling small animals, particularly reptiles, amphibians, small mammals and large invertebrates. It surpasses the detection ability of commonly used passive infrared (PIR) cameras for this application and eliminates problems such as high rates of false triggers and high variability in detection rates among cameras and study locations. Our system, which employs a HALT trigger, is capable of coupling to digital PIR cameras and is designed for detecting small animals traversing small tunnels, narrow trails, small clearings and along walls or drift fencing. PMID:28981533

Camera systems in human motion analysis for biomedical applications

NASA Astrophysics Data System (ADS)

Chin, Lim Chee; Basah, Shafriza Nisha; Yaacob, Sazali; Juan, Yeap Ewe; Kadir, Aida Khairunnisaa Ab.

2015-05-01

Human Motion Analysis (HMA) system has been one of the major interests among researchers in the field of computer vision, artificial intelligence and biomedical engineering and sciences. This is due to its wide and promising biomedical applications, namely, bio-instrumentation for human computer interfacing and surveillance system for monitoring human behaviour as well as analysis of biomedical signal and image processing for diagnosis and rehabilitation applications. This paper provides an extensive review of the camera system of HMA, its taxonomy, including camera types, camera calibration and camera configuration. The review focused on evaluating the camera system consideration of the HMA system specifically for biomedical applications. This review is important as it provides guidelines and recommendation for researchers and practitioners in selecting a camera system of the HMA system for biomedical applications.

Mixed-valence iron minerals on Venus: Fe(2+)-Fe(3+) oxides and oxy-silicates formed by surface-atmosphere interactions

NASA Technical Reports Server (NTRS)

Burns, Roger G.; Straub, Darcy W.

1992-01-01

Inferences from these investigations are that Fe(3+)-bearing minerals such as hematite magnesioferrite, acmite, and epidote are thermodynamically unstable, and that magnetite is the predominant mixed-valence iron oxide mineral on venus. Recently, the Fe(2+)-Fe(3+) silicate mineral laihunite was proposed to be a reaction product of olivine with the venusian atmosphere. This possibility is discussed further here. We suggest that other mixed-valence Fe(2+)-Fe(3+)-Oz-OH(-) silicates could also result from surface-atmosphere interactions on Venus. Topics discussed include the following: (1) conversion of hematite to magnetite; (2) stability of laihunite; (3) the possible existence of oxy-amphiboles and oxy-micas on Venus; and (4) other mixed-valence Fe(2+)-Fe(3+) silicates likely to exist on Venus.

Nekton Interaction Monitoring System

DOE Office of Scientific and Technical Information (OSTI.GOV)

2017-03-15

The software provides a real-time processing system for sonar to detect and track animals, and to extract water column biomass statistics in order to facilitate continuous monitoring of an underwater environment. The Nekton Interaction Monitoring System (NIMS) extracts and archives tracking and backscatter statistics data from a real-time stream of data from a sonar device. NIMS also sends real-time tracking messages over the network that can be used by other systems to generate other metrics or to trigger instruments such as an optical video camera. A web-based user interface provides remote monitoring and control. NIMS currently supports three popular sonarmore » devices: M3 multi-beam sonar (Kongsberg), EK60 split-beam echo-sounder (Simrad) and BlueView acoustic camera (Teledyne).« less

Precise and low-cost monitoring of plum curculio (Coleoptera: Curculionidae) pest activity in pyramid traps with cameras.

PubMed

Selby, R D; Gage, S H; Whalon, M E

2014-04-01

Incorporating camera systems into insect traps potentially benefits insect phenology modeling, nonlethal insect monitoring, and research into the automated identification of traps counts. Cameras originally for monitoring mammals were instead adapted to monitor the entrance to pyramid traps designed to capture the plum curculio, Conotrachelus nenuphar (Herbst) (Coleoptera: Curculionidae). Using released curculios, two new trap designs (v.I and v.II) were field-tested alongside conventional pyramid traps at one site in autumn 2010 and at four sites in autumn 2012. The traps were evaluated on the basis of battery power, ease-of-maintenance, adaptability, required-user-skills, cost (including labor), and accuracy-of-results. The v.II design fully surpassed expectations, except that some trapped curculios were not photographed. In 2012, 13 of the 24 traps recorded every curculio entering the traps during the 18-d study period, and in traps where some curculios were not photographed, over 90% of the omissions could be explained by component failure or external interference with the motion sensor. Significantly more curculios entered the camera traps between 1800 and 0000 hours. When compared with conventional pyramid traps, the v.I traps collected a similar number of curculios. Two observed but not significant trends were that the v.I traps collected twice as many plum curculios as the v.II traps, while at the same time the v.II traps collected more than twice as many photos per plum curculio as the v.I traps. The research demonstrates that low-cost, precise monitoring of field insect populations is feasible without requiring extensive technical expertise.

The SPICAV-SOIR instrument probing the atmosphere of Venus: an overview

NASA Astrophysics Data System (ADS)

Trompet, Loïc; Mahieux, Arnaud; Wilquet, Valérie; Robert, Séverine; Chamberlain, Sarah; Thomas, Ian; Carine Vandaele, Ann; Bertaux, Jean-Loup

2016-04-01

The Solar Occultation in the Infrared (SOIR) channel mounted on top of the SPICAV instrument of the ESA's Venus Express mission has observed the atmosphere of Venus during more than eight years. This IR spectrometer (2.2-4.3 μm) with a high spectral resolution (0.12 cm-1) combined an echelle grating with an acousto-optic tunable filter for order selection. SOIR performed more than 1500 solar occultation measurements leading to about two millions spectra. The Royal Belgian Institute for Space Aeronomy (BIRA-IASB) was in charge of SOIR's development and operations as well as its data pipeline. BIRA-IASB carried out several studies on the composition of Venus mesosphere and lower thermosphere: carbon dioxide, carbon monoxide, hydrogen halide (HF, HCl, DF, DCl), sulfur dioxide, water (H2O, HDO) as well as sulphuric acid aerosols in the upper haze of Venus. Density and temperature profiles of the upper atmosphere of Venus (60 km to 170 km) at the terminator have been retrieved from SOIR's spectra using different assumptions, wherein the hydrostatic equilibrium and the local thermodynamical equilibrium in the radiative transfer calculations. These results allow us to produce an Atmospheric model of Venus called Venus Atmosphere from SOIR measurements at the Terminator (VAST). Data obtained by SOIR will also contribute to update the Venus International Reference Atmosphere (VIRA). Recently, the treatment of the raw data to transmittance has been optimized, and a new dataset of spectra has been produced. All raw spectra (PSA level 2) as well as calibrated spectra (PSA level 3) have been delivered to ESA's Planetary Science Archive (PDSPSA). Consequently the re-analysis of all spectra has been undergone. We will briefly present the improvements implemented in the data pipeline. We will also show a compilation of results obtained by the instrument considering the complete mission duration.

Venus Atmospheric Maneuverable Platform (VAMP)

NASA Astrophysics Data System (ADS)

Shapiro Griffin, Kristen L.; Sokol, D.; Dailey, D.; Lee, G.; Polidan, R.

2013-10-01

We have explored a possible new approach to Venus upper atmosphere exploration by applying Northrop Grumman (non-NASA) development programs to the challenges associated with Venus upper atmosphere science missions. Our concept is a low ballistic coefficient (<50 Pa), semi-buoyant aircraft that deploys prior to entering the Venus atmosphere, enters the atmosphere without an aeroshell, and provides a long-lived (months to years), maneuverable vehicle capable of carrying science payloads to explore the Venus upper atmosphere. In this presentation we report results from our ongoing study and plans for future analyses and prototyping. We discuss the overall mission architecture and concept of operations from launch through Venus arrival, orbit, entry, and atmospheric science operations. We present a strawman concept of VAMP, including ballistic coefficient, planform area, percent buoyancy, inflation gas, wing span, vehicle mass, power supply, propulsion, materials considerations, structural elements, subsystems, and packaging. The interaction between the VAMP vehicle and the supporting orbiter will also be discussed. In this context, we specifically focus upon four key factors impacting the design and performance of VAMP: 1. Feasibility of and options for the deployment of the vehicle in space 2. Entry into the Venus atmosphere, including descent profile, heat rate, total heat load, stagnation temperature, control, and entry into level flight 3. Characteristics of flight operations and performance in the Venus atmosphere: altitude range, latitude and longitude access, day/night performance, aircraft performance (aerodynamics, power required vs. power available, propulsion, speed, percent buoyancy), performance sensitivity to payload weight 4. Science payload accommodation, constraints, and opportunities We discuss interdependencies of the above factors and the manner in which the VAMP strawman’s characteristics affect the CONOPs and the science objectives. We show how these factors provide constraints as well as enable opportunities for novel long duration scientific studies of the Venus upper atmosphere that support VEXAG goals 2 and 3.

Transits of Venus and Mercury: Exoplanet Analogs in Our Solar System

NASA Astrophysics Data System (ADS)

Pasachoff, Jay M.

2012-05-01

Since Johannes Kepler's predictions of transits of Mercury and Venus in 1631, and observations by Jeremiah Horrocks and William Crabtree of the 1639 transit of Venus, only 5 other transits of Venus have been observed: in 1761 and 1769, 1874 and 1882, and 2004. Expeditions were sent all over the world for the 18th and 19th century transits to follow the methods of Halley and others to determine the Astronomical Unit, giving the size and scale of the solar system, arguably the most important problem in astronomy for centuries. I will discuss how the infamous black-drop effect bedeviled astronomers in that quest for an accurate A.U., and how Glenn Schneider and I explained the effect through satellite observations of transits of Mercury, showing that it was not simply caused by the Cytherean atmosphere. During the 2004 transit, we worked with Richard Willson of ACRIMsat to detect the 0.1% drop in the Total Solar Irradiance, showing the effect of solar limb darkening, positioning such observations of transits of Venus and of Mercury as analogs to exoplanet transits. Our observations of the atmosphere of Venus with NASA's Transition Region and Coronal Explorer in 2004 led us to plan extensive observations of Venus's atmosphere and other phenomena during the June 5, 2012, transit of Venus, the last to be visible from Earth until 2117. We will have used NASA's Solar Dynamics Observatory, Hinode, ACRIMsat, and other spacecraft, and ground-based solar telescopes at Sacramento Peak, Kitt Peak, Big Bear, and Haleakala to observe the transit; I hope to give preliminary reports on these observations during this talk. Further, I will discuss the plans of Ehrenreich and colleagues for Hubble observations of this transit and our hopes of detecting transits of Venus and Earth as seen from Jupiter and Saturn over the next few years.

Venus' Chasmata and Earth's Spreading Centers: A Topographic Comparison

NASA Astrophysics Data System (ADS)

Stoddard, P. R.; Jurdy, D. M.

2008-12-01

Like the Earth, Venus has a global rift system, which has been cited as evidence of tectonic activity, despite the apparent lack of Earth-style plate tectonics. Both systems are marked by large ridges, usually with central grabens. On Earth, the topography of the rifts can be modeled well by a cooling half-space and the spreading of two divergent plates. The origin of the topographic signature on Venus, however, remains enigmatic. Venus' rift zones (termed "chasmata") can be fit by four great circle arcs extending 1000s of kilometers. The Venus chasmata system measures 54,464 km, which when corrected for the smaller size of the planet, nearly matches the 59,200-km total length of the spreading ridges determined for Earth. As on Earth, the chasmata with the greatest relief (7 km in just a 30-km run for Venus) represent the most recent tectonic activity. We use topographic profiles to look for well-understood terrestrial analogs to Venusian features. Focusing on mid-ocean ridge systems on Earth, we examine the variation along individual ridges, or rises, due to the gradual change in spreading rate (and thus cooling times). We then analyze the difference between fast and slow ridges, and propose that this technique may also be used to pick plate boundaries along spreading centers (SAM/AFR vs. NAM/AFR, e.g.). These profiles are then compared to those for Venus' rifts. Topographic profiles are based on the Magellan (Venus) and ETOPO5 (Earth) data sets. Long wavelength features appear similar to spreading systems on Earth, suggesting a deep, thermal cause. Short wavelength features, such as rift troughs and constructional edifices, are quite different, however, as expected from the vastly different surface conditions. Comparison of topographic profiles from Venus and Earth may lend insight into tectonic features and activity on our sister planet.

Chemistry of atmosphere-surface interactions on Venus and Mars

NASA Astrophysics Data System (ADS)

Fegley, Bruce, Jr.; Treiman, Allan H.

Earth-based, earth-orbital, and spacecraft observational data are used in the present evaluation of Venus atmosphere-surface interactions to quantitatively characterize the reactions between C, H, S, Cl, F, and N gases and plausible surface minerals. Calculation results are used to predict stable minerals and mineral assemblages on the Venus surface, in order to ascertain which (if any) of the atmospheric gases are buffeted by mineral assemblages. Chemical equilibrium calculations using extant thermodynamic data on scapolite minerals predict that carbonate-bearing scapolite and sulfate meionite are unstable on the surface of Venus, while chloride-bearing scapolite is stable.

Venus geology, geochemistry, and geophysics - Research results from the USSR

NASA Astrophysics Data System (ADS)

Barsukov, V. L.; Basilevsky, A. T.; Volkov, V. P.; Zharkov, V. N.

The book includes papers on the Venusian volcanism, hot-spot structures, the Lakshmi phenomenon, tesserae, ridge belts on plains, impact craters, evidence on the crustal dichotomy, the global tectonic style, resurfacing, and Venusian igneous rocks. Special attention is given to volatiles in the atmosphere and crust, the expansion of topography into spherical harmonics, rotation, statistical properties of topography and the gravity field, a physical model of Venus, and models of the thermal evolution of Venus. Also presented are an atlas of Venusian surface images and a table listing topographic features on Venus and their coordinates.

Elevation and igneous crater modification on Venus: Implications for magmatic volatile content

NASA Technical Reports Server (NTRS)

Wichman, R. W.

1993-01-01

Although most impact craters on Venus preserve nearly pristine crater rim and ejecta features, a small number of craters have been identified showing clear evidence of either igneous intrusion emplacement (floor-fracturing) beneath the crater floor or of volcanically embayed exterior ejecta deposits. Since the volcanically embayed craters consistently occur at higher elevations than the identified floor-fractured craters, this report proposes that igneous crater modification on Venus is elevation dependent. This report describes how regional variations in magmatic neutral buoyancy could produce such elevation dependent crater modification and considers the implications for typical magmatic volatile contents on Venus.

Oxygen ionization rates at Mars and Venus - Relative contributions of impact ionization and charge exchange

NASA Astrophysics Data System (ADS)

Zhang, M. H. G.; Luhmann, J. G.; Nagy, A. F.; Spreiter, J. R.; Stahara, S. S.

1993-02-01

Oxygen ion production rates above the ionopauses of Venus and Mars are calculated for photoionization, charge exchange, and solar wind electron impact ionization processes. The latter two require the use of the Spreiter and Stahara (1980) gas dynamic model to estimate magnetosheath velocities, densities, and temperatures. The results indicate that impact ionization is the dominant mechanism for the production of O(+) ions at both Venus and Mars. This finding might explain both the high ion escape rates measured by Phobos 2 and the greater mass loading rate inferred for Venus from the bow shock positions.

Mass-loading and the formation of the Venus tail

NASA Technical Reports Server (NTRS)

Russell, C. T.; Luhmann, J. G.; Saunders, M. A.

1985-01-01

Despite its lack of intrinsic magnetic field Venus has a well defined magnetotail, containing about 3 megawebers of magnetic flux in a tail about 4 Venus radii across with perhaps a slightly elliptical cross section. This tail arises through the mass-loading of magnetic flux tubes passing by the planet. Mass-loading can occur due to charge exchange and photoionization as well as from the diffusion of magnetic field into the ionosphere. Various evidence exists for the mass-loading process, including the direct observation of the picked up ions with both the Venera and Pioneer Venus plasma analyzers.

Venus Transit

NASA Image and Video Library

2012-06-05

It appeared that New Yorkers were not going to be able to see the transit of the planet Venus across the Sun, but just before the transit was over the sun broke through the clouds and Yvette Lee Kang was able to catch a glimpse of the transit on Tuesday, June 5, 2012 in New York. A transit of Venus occurs when the planet passes directly between the sun and earth. This alignment is rare, coming in pairs that are eight years apart but separated by over a century. The next Venus transit will be in December 2117. Photo Credit: (NASA/Bill Ingalls)

Geoid, topography, and convection-driven crustal deformation on Venus

NASA Technical Reports Server (NTRS)

Simons, Mark; Hager, Bradford H.; Solomon, Sean C.

1992-01-01

High-resolution Magellan images and altimetry of Venus reveal a wide range of styles and scales of surface deformation that cannot readily be explained within the classical terrestrial plate tectonic paradigm. The high correlation of long-wavelength topography and gravity and the large apparent depths of compensation suggest that Venus lacks an upper-mantle low-viscosity zone. A key difference between Earth and Venus may be the degree of coupling between the convecting mantle and the overlying lithosphere. Mantle flow should then have recognizable signatures in the relationships between surface topography, crustal deformation, and the observed gravity field.

The dayside ionospheres of Mars and Venus: Comparing a one-dimensional photochemical model with MaRS (Mars Express) and VeRa (Venus Express) observations

NASA Astrophysics Data System (ADS)

Peter, Kerstin; Pätzold, Martin; Molina-Cuberos, Gregorio; Witasse, Olivier; González-Galindo, F.; Withers, Paul; Bird, Michael K.; Häusler, Bernd; Hinson, David P.; Tellmann, Silvia; Tyler, G. Leonard

2014-05-01

The electron density distributions of the lower ionospheres of Mars and Venus are mainly dependent on the solar X-ray and EUV flux and the solar zenith angle. The influence of an increasing solar flux is clearly seen in the increase of the observed peak electron density and total electron content (TEC) of the main ionospheric layers. The model “Ionization in Atmospheres” (IonA) was developed to compare ionospheric radio sounding observations, which were performed with the radio science experiments MaRS on Mars Express and VeRa on Venus Express, with simulated electron density profiles of the Mars and Venus ionospheres. This was done for actual observation conditions (solar flux, solar zenith angle, planetary coordinates) from the bases of the ionospheres to ∼160 km altitude. IonA uses models of the neutral atmospheres at ionospheric altitudes (Mars Climate Database (MCD) v4.3 for Mars; VenusGRAM/VIRA for Venus) and solar flux information in the 0.5-95 nm wavelength range (X-ray to EUV) from the SOLAR2000 data base. The comparison between the observed electron density profiles and the IonA profiles for Mars, simulated for a selected MCD scenario (background atmosphere), shows that the general behavior of the Mars ionosphere is reproduced by all scenarios. The MCD “low solar flux/clear atmosphere” and “low solar flux/MY24” scenarios agree best (on average) with the MaRS set of observations, although the actual Mars atmosphere seemed to be still slightly colder at ionospheric altitudes. For Venus, the VenusGRAM model, based on VIRA, is too limited to be used for the IonA simulation of electron density profiles. The behavior of the V2 peak electron density and TEC as a function of solar zenith angle are in general reproduced, but the peak densities and the TEC are either over- or underestimated for low or high solar EUV fluxes, respectively. The simulated V2 peak altitudes are systematically underestimated by 5 km on average for solar zenith angles less than 45° and the peak altitudes rise for zenith angles larger than 60°. The latter is the opposite of the observed behavior. The explanation is that VIRA and VenusGRAM are valid only for high solar activity, although there is also very poor agreement with VeRa observations from the recent solar cycle, in which the solar activity increases to high values. The disagreement between the observation and simulation of the Venus electron density profiles proves, that the true encountered Venus atmosphere at ionospheric altitudes was denser but locally cooler than predicted by VIRA.

A risk-based coverage model for video surveillance camera control optimization

NASA Astrophysics Data System (ADS)

Zhang, Hongzhou; Du, Zhiguo; Zhao, Xingtao; Li, Peiyue; Li, Dehua

2015-12-01

Visual surveillance system for law enforcement or police case investigation is different from traditional application, for it is designed to monitor pedestrians, vehicles or potential accidents. Visual surveillance risk is defined as uncertainty of visual information of targets and events monitored in present work and risk entropy is introduced to modeling the requirement of police surveillance task on quality and quantity of vide information. the prosed coverage model is applied to calculate the preset FoV position of PTZ camera.

Innovative Seismological Techniques for Investigating the Interior Structure of Venus

NASA Astrophysics Data System (ADS)

Stevenson, D. J.; Cutts, J. A.; Mimoun, D.

2014-12-01

The formation, evolution and structure of Venus remain a mystery more than fifty years after the first visit by a robotic spacecraft. Radar images have revealed a surface that is much younger than those of the Moon, Mercury and Mars as well as a variety of enigmatic volcanic and tectonic features quite unlike those generated by plate tectonics on Earth. To understand how Venus works as a planet it is necessary to probe the interior of Venus. To accomplish this seismology must play a key role. Conventional seismology employs sensors in contact with the planetary surface but for Venus theses sensors must tolerate the Venus environment (460oC and 90 bars) for up to a year. The dense atmosphere of Venus, which efficiently couples seismic energy into the atmosphere as infrasonic waves, enables an alternative: detection of infrasonic waves in the upper atmosphere using either high altitude balloons or orbiting spacecraft. In June 2014, the Keck Institute for Space Studies (KISS) at the California Institute of Technology sponsored a one week workshop with 30 specialists in the key techniques and technologies that can bring these technique to readiness. In this paper, we describe the key synergies with earth science drawing on methods from terrestrial seismology and oceanography and identify key technical issues that need to be solved as well as important precursor measurements that should be made.

Understanding the variation in the millimeter-wave emission of Venus

NASA Technical Reports Server (NTRS)

Fahd, Antoine K.; Steffes, Paul G.

1992-01-01

Recent observations of the millimeter-wave emission from Venus at 112 GHz (2.6 mm) have shown significant variations in the continuum flux emission that may be attributed to the variability in the abundances of absorbing constituents in the Venus atmosphere. Such constituents include gaseous H2SO4, SO2, and liquid sulfuric acid (cloud condensates). Recently, Fahd and Steffes have shown that the effects of liquid H, SO4, and gaseous SO2 cannot completely account for this measured variability in the millimeter-wave emission of Venus. Thus, it is necessary to study the effect of gaseous H2SO4 on the millimeter-wave emission of Venus. This requires knowledge of the millimeter-wavelength (MMW) opacity of gaseous H2SO4, which unfortunately has never been determined for Venus-like conditions. We have measured the opacity of gaseous H2SO4 in a CO2 atmosphere at 550, 570, and 590 K, at 1 and 2 atm total pressure, and at a frequency of 94.1 GHz. Our results, in addition to previous centimeter-wavelength results are used to verify a modeling formalism for calculating the expected opacity of this gaseous mixture at other frequencies. This formalism is incorporated into a radiative transfer model to study the effect of gaseous H2SO4 on the MMW emission of Venus.

Monitoring the spatial and temporal evolution of slope instability with Digital Image Correlation

NASA Astrophysics Data System (ADS)

Manconi, Andrea; Glueer, Franziska; Loew, Simon

2017-04-01

The identification and monitoring of ground deformation is important for an appropriate analysis and interpretation of unstable slopes. Displacements are usually monitored with in-situ techniques (e.g., extensometers, inclinometers, geodetic leveling, tachymeters and D-GPS), and/or active remote sensing methods (e.g., LiDAR and radar interferometry). In particular situations, however, the choice of the appropriate monitoring system is constrained by site-specific conditions. Slope areas can be very remote and/or affected by rapid surface changes, thus hardly accessible, often unsafe, for field installations. In many cases the use of remote sensing approaches might be also hindered because of unsuitable acquisition geometries, poor spatial resolution and revisit times, and/or high costs. The increasing availability of digital imagery acquired from terrestrial photo and video cameras allows us nowadays for an additional source of data. The latter can be exploited to visually identify changes of the scene occurring over time, but also to quantify the evolution of surface displacements. Image processing analyses, such as Digital Image Correlation (known also as pixel-offset or feature-tracking), have demonstrated to provide a suitable alternative to detect and monitor surface deformation at high spatial and temporal resolutions. However, a number of intrinsic limitations have to be considered when dealing with optical imagery acquisition and processing, including the effects of light conditions, shadowing, and/or meteorological variables. Here we propose an algorithm to automatically select and process images acquired from time-lapse cameras. We aim at maximizing the results obtainable from large datasets of digital images acquired with different light and meteorological conditions, and at retrieving accurate information on the evolution of surface deformation. We show a successful example of application of our approach in the Swiss Alps, more specifically in the Great Aletsch area, where slope instability was recently reactivated due to the progressive glacier retreat. At this location, time-lapse cameras have been installed during the last two years, ranging from low-cost and low-resolution webcams to more expensive high-resolution reflex cameras. Our results confirm that time-lapse cameras provide quantitative and accurate measurements of surface deformation evolution over space and time, especially in situations when other monitoring instruments fail.

Unmanned Aerial Vehicles for Environmental Monitoring with Special Reference to Heat Loss

NASA Astrophysics Data System (ADS)

Anweiler, Stanisław; Piwowarski, Dawid; Ulbrich, Roman

2017-10-01

This paper presents the design and implementation of device for remote and automatic monitoring of temperature field of large objects. The project aimed to create a quadcopter flying platform equipped with a thermal imaging camera. The object of the research was district heating installations above ground and underground. The results of the work on the implementation of low-cost (below 750 EUR) and efficient heat loss monitoring system. The system consists of a small (<2kg) multirotor platform. To perform thermal images micro camera FlirOne with microcomputer Raspberry Pi3 was used. Exploitation of UAVs in temperature field monitoring reveals only a fraction of their capabilities. The fast-growing multirotor platform market continues to deliver new solutions and improvements. Their use in monitoring the environment is limited only by the imagination of the user.

Availability Issues in Wireless Visual Sensor Networks

PubMed Central

Costa, Daniel G.; Silva, Ivanovitch; Guedes, Luiz Affonso; Vasques, Francisco; Portugal, Paulo

2014-01-01

Wireless visual sensor networks have been considered for a large set of monitoring applications related with surveillance, tracking and multipurpose visual monitoring. When sensors are deployed over a monitored field, permanent faults may happen during the network lifetime, reducing the monitoring quality or rendering parts or the entire network unavailable. In a different way from scalar sensor networks, camera-enabled sensors collect information following a directional sensing model, which changes the notions of vicinity and redundancy. Moreover, visual source nodes may have different relevancies for the applications, according to the monitoring requirements and cameras' poses. In this paper we discuss the most relevant availability issues related to wireless visual sensor networks, addressing availability evaluation and enhancement. Such discussions are valuable when designing, deploying and managing wireless visual sensor networks, bringing significant contributions to these networks. PMID:24526301

Large scale atmospheric waves in the Venus mesosphere as seen by the VeRa Radio Science instrument on Venus Express

NASA Astrophysics Data System (ADS)

Tellmann, S.; Häusler, B.; Hinson, D. P.; Tyler, G. L.; Andert, T. P.; Bird, M. K.; Imamura, T.; Pätzold, M.; Remus, S.

2014-04-01

Atmospheric waves on almost all spatial scales have been observed in the Venus atmosphere in various atmospheric regions. They play a crucial role in the redistribution of energy, momentum, and atmospheric constituent and are thought to be involved in the development and maintenance of the atmospheric superrotation.

Venus - Ishtar gravity anomaly

NASA Technical Reports Server (NTRS)

Sjogren, W. L.; Bills, B. G.; Mottinger, N. A.

1984-01-01

The gravity anomaly associated with Ishtar Terra on Venus is characterized, comparing line-of-sight acceleration profiles derived by differentiating Pioneer Venus Orbiter Doppler residual profiles with an Airy-compensated topographic model. The results are presented in graphs and maps, confirming the preliminary findings of Phillips et al. (1979). The isostatic compensation depth is found to be 150 + or - 30 km.

High-oleic Virginia peanuts in the Southwestern US: A summary of data supporting the release of 'VENUS'

USDA-ARS?s Scientific Manuscript database

'VENUS' is a large-seeded high-oleic Virginia-type peanut (Arachis hypogaea L. subsp. hypogaea var. hypogaea) that has enhanced Sclerotinia blight and pod rot tolerance when compared to the cultivar Jupiter. 'VENUS' is the first high-oleic Virginia peanut developed for and proposed for release in t...

Coherent infrared imaging camera (CIRIC)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hutchinson, D.P.; Simpson, M.L.; Bennett, C.A.

1995-07-01

New developments in 2-D, wide-bandwidth HgCdTe (MCT) and GaAs quantum-well infrared photodetectors (QWIP) coupled with Monolithic Microwave Integrated Circuit (MMIC) technology are now making focal plane array coherent infrared (IR) cameras viable. Unlike conventional IR cameras which provide only thermal data about a scene or target, a coherent camera based on optical heterodyne interferometry will also provide spectral and range information. Each pixel of the camera, consisting of a single photo-sensitive heterodyne mixer followed by an intermediate frequency amplifier and illuminated by a separate local oscillator beam, constitutes a complete optical heterodyne receiver. Applications of coherent IR cameras are numerousmore » and include target surveillance, range detection, chemical plume evolution, monitoring stack plume emissions, and wind shear detection.« less

Brownian Movement and Avogadro's Number: A Laboratory Experiment.

ERIC Educational Resources Information Center

Kruglak, Haym

1988-01-01

Reports an experimental procedure for studying Einstein's theory of Brownian movement using commercially available latex microspheres and a video camera. Describes how students can monitor sphere motions and determine Avogadro's number. Uses a black and white video camera, microscope, and TV. (ML)

Remote camera observations of lava dome growth at Mount St. Helens, Washington, October 2004 to February 2006: Chapter 11 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

USGS Publications Warehouse

Poland, Michael P.; Dzurisin, Daniel; LaHusen, Richard G.; Major, John J.; Lapcewich, Dennis; Endo, Elliot T.; Gooding, Daniel J.; Schilling, Steve P.; Janda, Christine G.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

2008-01-01

Images from a Web-based camera (Webcam) located 8 km north of Mount St. Helens and a network of remote, telemetered digital cameras were used to observe eruptive activity at the volcano between October 2004 and February 2006. The cameras offered the advantages of low cost, low power, flexibility in deployment, and high spatial and temporal resolution. Images obtained from the cameras provided important insights into several aspects of dome extrusion, including rockfalls, lava extrusion rates, and explosive activity. Images from the remote, telemetered digital cameras were assembled into time-lapse animations of dome extrusion that supported monitoring, research, and outreach efforts. The wide-ranging utility of remote camera imagery should motivate additional work, especially to develop the three-dimensional quantitative capabilities of terrestrial camera networks.

Comparing Volcanic Terrains on Venus and Earth: How Prevalent are Pyroclastic Deposits on Venus?

NASA Technical Reports Server (NTRS)

Carter, Lynn M.; Campbell, B. A.; Glaze, L. S.

2012-01-01

In the last several years, astronomers have discovered several exoplanets with masses less than 10 times that of the Earth [1]. Despite the likely abundance of Earth-sized planets, little is known about the pathways through which these planets evolve to become habitable or uninhabitable. Venus and Earth have similar planetary radii and solar orbital distance, and therefore offer a chance to study in detail the divergent evolution of two objects that now have radically different climates. Understanding the extent, duration, and types of volcanism present on Venus is an important step towards understanding how volatiles released from the interior of Venus have influenced the development of the atmosphere. Placing constraints on the extent of explosive volcanism on Venus can provide boundary conditions for timing, volumes, and altitudes for atmospheric injection of volatiles. In addition, atmospheric properties such as near-surface temperature and density affect how interior heat and volatiles are released. Radar image data for Venus can be used to determine the physical properties of volcanic deposits, and in particular, they can be used to search for evidence of pyroclastic deposits that may result from explosive outgassing of volatiles. For explosive volcanism to occur with the current high atmospheric pressure, magma volatile contents must be higher than is typical on Earth (at least 2-4% by weight) [2,3]. In, addition, pyroclastic flows should be more prevalent on Venus than convective plumes and material may not travel as far from the vent source as it would on Earth [3]. Areas of high radar backscatter with wispy margins that occur near concentric fractures on Sapho Patera [4] and several coronae in Eastern Eistla Regio [5] have been attributed to collapse of eruption columns and runout of rough materials.

Methane measurement by the Pioneer Venus large probe neutral mass spectrometer

NASA Technical Reports Server (NTRS)

Donahue, T. M.; Hodges, R. R., Jr.

1992-01-01

The Pioneer Venus Large Probe Mass Spectrometer detected a large quantity of methane as it descended below 20 km in the atmosphere of Venus. Terrestrial methane and Xe-136, both originating in the same container and flowing through the same plumbing, were deliberately released inside the mass spectrometer for instrumental reasons. However, the Xe-136 did not exhibit behavior similar to methane during Venus entry, nor did CH4 in laboratory simulations. The CH4 was deuterium poor compared to Venus water and hydrogen. While the inlet to the mass spectrometer was clogged with sulfuric acid droplets, significant deuteration of CH4 and its H2 progeny was observed. Since the only source of deuterium identifiable was water from sulfuric acid, we have concluded that we should correct the HDO/H2O ratio in Venus water from 3.2 x 10(exp -2) to (5 plus or minus 0.7) x 10(exp -2). When the probe was in the lower atmosphere, transfer of deuterium from Venus HDO and HD to CH4 can account quantitatively for the deficiencies recorded in HDO and HD below 10 km, and consequently, the mysterious gradients in water vapor and hydrogen mixing ratios we have reported. The revision in the D/H ratio reduces the mixing ratio of water vapor (and H2) reported previously by a factor of 3.2/5. We are not yet able to say whether the methane detected was atmospheric or an instrumental artifact. If it was atmospheric, its release must have been episodic and highly localized. Otherwise, the large D/H ratio in Venus water and hydrogen could not be maintained.

Methane measurement by the Pioneer Venus large probe neutral mass spectrometer

NASA Astrophysics Data System (ADS)

Donahue, T. M.; Hodges, R. R., Jr.

1992-12-01

The Pioneer Venus Large Probe Mass Spectrometer detected a large quantity of methane as it descended below 20 km in the atmosphere of Venus. Terrestrial methane and Xe-136, both originating in the same container and flowing through the same plumbing, were deliberately released inside the mass spectrometer for instrumental reasons. However, the Xe-136 did not exhibit behavior similar to methane during Venus entry, nor did CH4 in laboratory simulations. The CH4 was deuterium poor compared to Venus water and hydrogen. While the inlet to the mass spectrometer was clogged with sulfuric acid droplets, significant deuteration of CH4 and its H2 progeny was observed. Since the only source of deuterium identifiable was water from sulfuric acid, we have concluded that we should correct the HDO/H2O ratio in Venus water from 3.2 x 10-2 to (5 plus or minus 0.7) x 10-2. When the probe was in the lower atmosphere, transfer of deuterium from Venus HDO and HD to CH4 can account quantitatively for the deficiencies recorded in HDO and HD below 10 km, and consequently, the mysterious gradients in water vapor and hydrogen mixing ratios we have reported. The revision in the D/H ratio reduces the mixing ratio of water vapor (and H2) reported previously by a factor of 3.2/5. We are not yet able to say whether the methane detected was atmospheric or an instrumental artifact. If it was atmospheric, its release must have been episodic and highly localized. Otherwise, the large D/H ratio in Venus water and hydrogen could not be maintained.

Insect haptoelectrical stimulation of Venus flytrap triggers exocytosis in gland cells.

PubMed

Scherzer, Sönke; Shabala, Lana; Hedrich, Benjamin; Fromm, Jörg; Bauer, Hubert; Munz, Eberhard; Jakob, Peter; Al-Rascheid, Khaled A S; Kreuzer, Ines; Becker, Dirk; Eiblmeier, Monika; Rennenberg, Heinz; Shabala, Sergey; Bennett, Malcolm; Neher, Erwin; Hedrich, Rainer

2017-05-02

The Venus flytrap Dionaea muscipula captures insects and consumes their flesh. Prey contacting touch-sensitive hairs trigger traveling electrical waves. These action potentials (APs) cause rapid closure of the trap and activate secretory functions of glands, which cover its inner surface. Such prey-induced haptoelectric stimulation activates the touch hormone jasmonate (JA) signaling pathway, which initiates secretion of an acidic hydrolase mixture to decompose the victim and acquire the animal nutrients. Although postulated since Darwin's pioneering studies, these secretory events have not been recorded so far. Using advanced analytical and imaging techniques, such as vibrating ion-selective electrodes, carbon fiber amperometry, and magnetic resonance imaging, we monitored stimulus-coupled glandular secretion into the flytrap. Trigger-hair bending or direct application of JA caused a quantal release of oxidizable material from gland cells monitored as distinct amperometric spikes. Spikes reminiscent of exocytotic events in secretory animal cells progressively increased in frequency, reaching steady state 1 d after stimulation. Our data indicate that trigger-hair mechanical stimulation evokes APs. Gland cells translate APs into touch-inducible JA signaling that promotes the formation of secretory vesicles. Early vesicles loaded with H + and Cl - fuse with the plasma membrane, hyperacidifying the "green stomach"-like digestive organ, whereas subsequent ones carry hydrolases and nutrient transporters, together with a glutathione redox moiety, which is likely to act as the major detected compound in amperometry. Hence, when glands perceive the haptoelectrical stimulation, secretory vesicles are tailored to be released in a sequence that optimizes digestion of the captured animal.

Planetcam: A Visible And Near Infrared Lucky-imaging Camera To Study Planetary Atmospheres And Solar System Objects

NASA Astrophysics Data System (ADS)

Sanchez-Lavega, Agustin; Rojas, J.; Hueso, R.; Perez-Hoyos, S.; de Bilbao, L.; Murga, G.; Ariño, J.; Mendikoa, I.

2012-10-01

PlanetCam is a two-channel fast-acquisition and low-noise camera designed for a multispectral study of the atmospheres of the planets (Venus, Mars, Jupiter, Saturn, Uranus and Neptune) and the satellite Titan at high temporal and spatial resolutions simultaneously invisible (0.4-1 μm) and NIR (1-2.5 μm) channels. This is accomplished by means of a dichroic beam splitter that separates both beams directing them into two different detectors. Each detector has filter wheels corresponding to the characteristic absorption bands of each planetary atmosphere. Images are acquired and processed using the “lucky imaging” technique in which several thousand images of the same object are obtained in a short time interval, coregistered and ordered in terms of image quality to reconstruct a high-resolution ideally diffraction limited image of the object. Those images will be also calibrated in terms of intensity and absolute reflectivity. The camera will be tested at the 50.2 cm telescope of the Aula EspaZio Gela (Bilbao) and then commissioned at the 1.05 m at Pic-duMidi Observatory (Franca) and at the 1.23 m telescope at Calar Alto Observatory in Spain. Among the initially planned research targets are: (1) The vertical structure of the clouds and hazes in the planets and their scales of variability; (2) The meteorology, dynamics and global winds and their scales of variability in the planets. PlanetCam is also expected to perform studies of other Solar System and astrophysical objects. Acknowledgments: This work was supported by the Spanish MICIIN project AYA2009-10701 with FEDER funds, by Grupos Gobierno Vasco IT-464-07 and by Universidad País Vasco UPV/EHU through program UFI11/55.

Superrotation on Venus, on Titan, and Elsewhere

NASA Astrophysics Data System (ADS)

Read, Peter L.; Lebonnois, Sebastien

2018-05-01

The superrotation of the atmospheres of Venus and Titan has puzzled dynamicists for many years and seems to put these planets in a very different dynamical regime from most other planets. In this review, we consider how to define superrotation objectively and explore the constraints that determine its occurrence. Atmospheric superrotation also occurs elsewhere in the Solar System and beyond, and we compare Venus and Titan with Earth and other planets for which wind estimates are available. The extreme superrotation on Venus and Titan poses some difficult challenges for numerical models of atmospheric circulation, much more difficult than for more rapidly rotating planets such as Earth or Mars. We consider mechanisms for generating and maintaining a superrotating state, all of which involve a global meridional overturning circulation. The role of nonaxisymmetric eddies is crucial, however, but the detailed mechanisms may differ between Venus, Titan, and other planets.

Venus geology

NASA Astrophysics Data System (ADS)

McLaughlin, W. I.

1991-05-01

The Magellan mission to Venus is reviewed. The scientific investigations conducted by 243-day cycles encompass mapping with a constant incidence angle for the radar, observing surface changes from one cycle to the next, and targeting young-looking volcanos. The topography of Venus is defined by the upper boundary of the crust and upwelling from lower domains. Tectonic features such as rift zones, linear mountain belts, ridge belts, and tesserae are described. The zones of tesserae are unique to the planet. Volcanism accounts for about 80 percent of the observed surface, the remainder being volcanic deposits which have been reworked by tectonism or impacts. Magellan data reveal about 900 impact craters with flow-like ejecta resulting from the fall of meteoroids. It is concluded that the age of the Venusian surface varies between 0 and 800 million years. Tectonic and volcanic activities dominate the formation of the Venus topography; such processes as weathering and erosion are relatively unimportant on Venus.

Venus Interior Probe Using In-Situ Power and Propulsion (VIP-INSPR)

NASA Technical Reports Server (NTRS)

Bugga, Ratnakumar V.

2016-01-01

Venus, despite being our closest neighboring planet, is under-explored due to its hostile and extreme environment, with a 92 bar pressure and 467 C temperature at the surface. The temperature decreases at higher altitudes, almost at the rate of 7.9 C/km, reaching the Earth surface conditions at 65 km. Due to the less extreme conditions, balloon missions could survive as long as 46 h at an altitude of 54 km. However, because of the opacity of the Venus atmosphere filled with clouds of sulfuric acid and CO2, orbiter or balloon missions are not as revealing and informative in characterizing the surface, as similar missions on Moon and Mars. To understand the evolutionary paths of Venus in relation to Earth, it is imperative to gather basic information on the crust, mantle, core, atmosphere/exosphere and bulk composition of Venus, through in-situ investigations using landers, probes and variable altitude areal platforms.

A 3D Multi-fluid MHD Study of the Interaction of the Solar Wind with the Ionosphere/Atmosphere System of Venus.

NASA Astrophysics Data System (ADS)

Najib, D.; Nagy, A.; Toth, G.; Ma, Y.-J.

2011-10-01

We use the latest version of our four species multifluid model to study the interaction of the solar wind with Venus. The model solves simultaneously the continuity, momentum and energy equations of the different ions. The lower boundary of our model is at 100 km, below the main ionospheric peak, and the radial resolution is about 10 km in the ionosphere, thus the model does a very good job in reproducing the ionosphere and the associated processes. We carry out calculations for high and low solar activity conditions and establish the importance of mass loading by the extended exosphere of Venus. We demonstrate the importance of using the multi-fluid rather than a single fluid model. We also calculate the atmospheric escape of the ionospheric species and compare our model results with the observed parameters from Pioneer Venus and Venus Express.

The thermal balance of the lower atmosphere of Venus

NASA Technical Reports Server (NTRS)

Tomasko, M. G.

1981-01-01

The temperature near the surface of Venus (now established at 730 K) is remarkably high in view of Venus's cloud cover which causes the planet to absorb even less sunlight than does Earth. Early attempts to understand the thermal balance that leads to this unusual state were hindered by the lack of basic information regarding the composition, temperature-pressure structure, cloud properties, and wind field of the lower atmosphere. A series of successful space missions have measured many of the above quantities that control the transfer of heat in Venus's lower atmosphere. The relevant observational data are summarized and the attempts to understand the thermal balance of Venus's atmosphere below the cloud tops are reviewed. The data indicate that sufficient sunlight penetrates to deep atmospheric levels and is trapped by the large thermal opacity of the atmosphere to essentially account for the high temperatures observed.

Neutral Mass Spectrometry for Venus Atmosphere and Surface

NASA Technical Reports Server (NTRS)

Mahaffy, Paul

2004-01-01

The nature of the divergent evolution of the terrestrial planets Venus, Earth, and Mars is a fundamental problem in planetary science that is most relevant to understanding the characteristics of small planets we are likely to discover in extrasolar systems and the number of such systems that may support habitable environments. For this reason, the National Research Council's Decadal Survey gives Venus exploration high priority. That report was the basis of the NASA selection of Venus as one of four prime mission targets for the recently initiated New Frontiers Program. If the Decadal Survey priorities are to be realized, in situ Venus exploration must remain a high priority. Remote sensing orbital and in situ atmospheric measurements from entry probe or balloon platforms might be realized under the low cost Discovery missions while both atmospheric and landed surface measurements are envisioned with the intermediate class missions of the New Frontiers Program.

Visual aid titled 'The Magellan Mission to Venus'

NASA Technical Reports Server (NTRS)

1988-01-01

Visual aid titled 'The Magellan Mission to Venus' describes data that will be collected and science objectives. Images and brightness temperatures will be obtained for 70-90% of the surface, with a radar resolution of 360 meters or better. The global gravity field model will be refined by combining Magellan and Pioneer-Venus doppler data. Altimetry data will be used to measure the topography of 70-90% of the surface with a vertical accuracy of 120-360 meters. Science objectives include: to improve the knowledge of the geological history of Venus by analysis of the surface morphology and electrical properties and the processes that control them; and to improve the knowledge of the geophysics of Venus, principally its density distribution and dynamics. Magellan, named for the 16th century Portuguese explorer, will be deployed from the payload bay (PLB) of Atlantis, Orbiter Vehicle (OV) 104, during mission STS-30.

Experimental Investigation into the Radar Anomalies on the Surface of Venus

NASA Technical Reports Server (NTRS)

Kohler, E.; Gavin, P.; Chevrier, V.; Johnson, Natasha M.

2012-01-01

Radar mapping of thc surface of Venus shows areas of high reflectivity (low emissivity) in the Venusian highlands at altitudes between 2.5-4.75 kilometers. The origin of the radar anomalies found in the Venusian highlands remains unclear. Most explanations of the potential causes for these radar anomalies come from theoretical work. Previous studies suggest increased surface roughness or materials with higher dielectric constants as well as surface atmospheric interactions. Several possible candidates of high-dielectric materials are tellurium) ferroelectric materials, and lead or bismuth sulfides. While previous studies have been influential in determining possible sources for the Venus anomalies, only a very few hypotheses have been verified via experimentation. This work intends to experimentally constrain the source of the radar anomalies on Venus. This study proposes to investigate four possible materials that could potentially cause the high reflectivities on the surface of Venus and tests their behavior under simulated Venusian conditions.

Effects of turbulence in the atmosphere of Venus on Pioneer Venus radio, phase 1

NASA Technical Reports Server (NTRS)

Woo, R.; Kendall, W.; Ishimaru, A.; Berwin, R.

1973-01-01

The prediction of the turbulence effects in the Venus atmosphere on Pioneer Venus radio was investigated. A careful investigation based on a theoretical and experimental study of the power spectrum of the Mariner 5 amplitude fluctuations is carried out and the results contribute considerably to our scientific knowledge of turbulence in the atmosphere of Venus. Fully developed turbulence is seen to exist predominantly in the altitude range of 41 - 49 km. This result is consistent with the high wind shear and wind velocities observed by Venera 4 for altitudes higher than 40 km. The outer scale size of turbulence is on the order of 100 m, the structure constant for the dayside atmosphere 3.9 x 10 to the -7 power m to the -1/3rd power, and that for the nightside atmosphere 2.9 x 10 to the -7 power m to the -1/3rd power.

Optimization and verification of image reconstruction for a Compton camera towards application as an on-line monitor for particle therapy

NASA Astrophysics Data System (ADS)

Taya, T.; Kataoka, J.; Kishimoto, A.; Tagawa, L.; Mochizuki, S.; Toshito, T.; Kimura, M.; Nagao, Y.; Kurita, K.; Yamaguchi, M.; Kawachi, N.

2017-07-01

Particle therapy is an advanced cancer therapy that uses a feature known as the Bragg peak, in which particle beams suddenly lose their energy near the end of their range. The Bragg peak enables particle beams to damage tumors effectively. To achieve precise therapy, the demand for accurate and quantitative imaging of the beam irradiation region or dosage during therapy has increased. The most common method of particle range verification is imaging of annihilation gamma rays by positron emission tomography. Not only 511-keV gamma rays but also prompt gamma rays are generated during therapy; therefore, the Compton camera is expected to be used as an on-line monitor for particle therapy, as it can image these gamma rays in real time. Proton therapy, one of the most common particle therapies, uses a proton beam of approximately 200 MeV, which has a range of ~ 25 cm in water. As gamma rays are emitted along the path of the proton beam, quantitative evaluation of the reconstructed images of diffuse sources becomes crucial, but it is far from being fully developed for Compton camera imaging at present. In this study, we first quantitatively evaluated reconstructed Compton camera images of uniformly distributed diffuse sources, and then confirmed that our Compton camera obtained 3 %(1 σ) and 5 %(1 σ) uniformity for line and plane sources, respectively. Based on this quantitative study, we demonstrated on-line gamma imaging during proton irradiation. Through these studies, we show that the Compton camera is suitable for future use as an on-line monitor for particle therapy.

A new concept of real-time security camera monitoring with privacy protection by masking moving objects

NASA Astrophysics Data System (ADS)

Yabuta, Kenichi; Kitazawa, Hitoshi; Tanaka, Toshihisa

2006-02-01

Recently, monitoring cameras for security have been extensively increasing. However, it is normally difficult to know when and where we are monitored by these cameras and how the recorded images are stored and/or used. Therefore, how to protect privacy in the recorded images is a crucial issue. In this paper, we address this problem and introduce a framework for security monitoring systems considering the privacy protection. We state requirements for monitoring systems in this framework. We propose a possible implementation that satisfies the requirements. To protect privacy of recorded objects, they are made invisible by appropriate image processing techniques. Moreover, the original objects are encrypted and watermarked into the image with the "invisible" objects, which is coded by the JPEG standard. Therefore, the image decoded by a normal JPEG viewer includes the objects that are unrecognized or invisible. We also introduce in this paper a so-called "special viewer" in order to decrypt and display the original objects. This special viewer can be used by limited users when necessary for crime investigation, etc. The special viewer allows us to choose objects to be decoded and displayed. Moreover, in this proposed system, real-time processing can be performed, since no future frame is needed to generate a bitstream.

High-Performance Solid-State and Fiber Lasers Controlled by Volume Bragg Gratings

DTIC Science & Technology

2013-09-01

Glebov: Proc. SPIE 8237 (2012) 823705. 12） I. Divliansky, D. Ott, B. Anderson, G. Venus, and L. Glebov: To be published in Opt. Express. 13） A. Jain...B. Anderson, D. Drachenberg, V. Rotar, G. Venus, and L. Glebov: Proc. SPIE 8237 (2012) 823705. 47） B. Anderson, S. Kaim, G. B. Venus, J. Lumeau, V

Lunar and Planetary Science XXXV: Venus

NASA Technical Reports Server (NTRS)

2004-01-01

The session"Venus" included the following reports:Venera-Vega Geochemical Analyses: What Geologic Units are the Source of the Analyzed Material?; Mapping of Rift Zones on Venus, Preliminary Results: Spatial Distribution, Relationship with Regional Plains, Morphology of Fracturing, Topography and Style of Volcanism; An Effect of Stimulated Radiation Processes on Radio Emission from Major Planets; and Venusian Craters and the Origin of Coronae.

Taking Venus models to new dimensions.

NASA Astrophysics Data System (ADS)

Murawski, K.

1997-11-01

Space plasma physicists in Poland and Japan have gained new insights into the interaction between the solar wind and Venus. Computer simulations of this 3D global interaction between the solar wind and nonmagnetized bodies have enabled greater understanding of the large-scale processes involved in such phenomena. A model that offers improved understanding of the solar wind interaction with Venus (as well as other nonmagnetized bodies impacted by the solar wind) has been developed. In this model, the interaction of the solar wind with the ionosphere of Venus is studied by calculating numerical solutions of the 3D MHD equations for two-component, chemically reactive plasma. The author describes the innovative model.

Quantitative analysis of terrain units mapped in the northern quarter of Venus from Venera 15/16 data

NASA Technical Reports Server (NTRS)

Schaber, G. G.

1991-01-01

The contacts between 34 geological/geomorphic terrain units in the northern quarter of Venus mapped from Venera 15/16 data were digitized and converted to a Sinusoidal Equal-Area projection. The result was then registered with a merged Pioneer Venus/Venera 15/16 altimetric database, root mean square (rms) slope values, and radar reflectivity values derived from Pioneer Venus. The resulting information includes comparisons among individual terrain units and terrain groups to which they are assigned in regard to percentage of map area covered, elevation, rms slopes, distribution of suspected craters greater than 10 km in diameter.

Does Venus wobble

NASA Technical Reports Server (NTRS)

Yoder, C. F.; Ward, W. R.

1979-01-01

The free wobble damping time for Venus due to solar tides and rotational flexing is found to be approximately 700,000 times Q sub omega years, where Q sub omega is the dissipation function associated with the wobble frequency. The slow spin and expected small (nonhydrostatic) J2 predict a very long wobble period of about 100,000 years. As a result, a simple scaling of the earth's Chandler wobble excitation rate to that of Venus suggests that an appreciable wobble could exist. Detection (or lack thereof) of a free wobble may thus place constraints on the dynamic activity (e.g., mantle convection, Venusquakes, etc.) of the Venus interior.

Analysis of Solar Cell Efficiency for Venus Atmosphere and Surface Missions

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A.; Haag, Emily

2013-01-01

A simplified model of solar power in the Venus environment is developed, in which the solar intensity, solar spectrum, and temperature as a function of altitude is applied to a model of photovoltaic performance, incorporating the temperature and intensity dependence of the open-circuit voltage and the temperature dependence of the bandgap and spectral response of the cell. We use this model to estimate the performance of solar cells for both the surface of Venus and for atmospheric probes at altitudes from the surface up to 60 km. The model shows that photovoltaic cells will produce power even at the surface of Venus.

Regional mantle upwelling on Venus: The Beta-Atla-Themis anomaly and correlation with global tectonic patterns

NASA Technical Reports Server (NTRS)

Crumpler, L. S.; Head, J. W.; Aubele, Jayne C.

1993-01-01

The morphology and global distribution of volcanic centers and their association with other geological characteristics offers significant insight into the global patterns of geology, tectonic style, thermal state, and interior dynamics of Venus. Magellan data permit the detailed geological interpretation necessary to address questions about interior dynamics of Venus particularly as they reflect relatively physical, chemical, and thermal conditions of the interior. This paper focuses on the distribution of anomalous concentrations of volcanic centers on Venus and regional patterns of tectonic deformation as it may relate to the identification of global internal anomalies, including mantle dynamic, petrological, or thermal patterns.

Venus: The First Habitable World of Our Solar System?

NASA Technical Reports Server (NTRS)

Way, Michael Joseph; Del Genio, Anthony; Kiang, Nancy; Sohl, Linda; Clune, Tom; Aleinov, Igor; Kelley, Maxwell

2015-01-01

A great deal of effort in the search for life off-Earth in the past 20+ years has focused on Mars via a plethora of space and ground based missions. While there is good evidence that surface liquid water existed on Mars in substantial quantities, it is not clear how long such water existed. Most studies point to this water existing billions of years ago. However,those familiar with the Faint Young Sun hypothesis for Earth will quickly realize that this problem is even more pronounced for Mars. In this context recent simulations have been completed with the GISS 3-D GCM (1) of paleo Venus (approx. 3 billion years ago) when the sun was approx. 25 less luminous than today. A combination of a less luminous Sun and a slow rotation rate reveal that Venus could have had conditions on its surface amenable to surface liquid water. Previous work has also provided bounds on how much water Venus could have had using measured DH ratios. It is possible that less assumptions have to be made to make Venus an early habitable world than have to be made for Mars, even thoughVenus is a much tougher world on which to confirm this hypothesis.

Advancing Venus Geophysics with the NF4 VOX Gravity Investigation.

NASA Astrophysics Data System (ADS)

Iess, L.; Mazarico, E.; Andrews-Hanna, J. C.; De Marchi, F.; Di Achille, G.; Di Benedetto, M.; Smrekar, S. E.

2017-12-01

The Venus Origins Explorer is a JPL-led New Frontiers 4 mission proposal to Venus to answer critical questions about the origin and evolution of Venus. Venus stands out among other planets as Earth's twin planet, and is a natural target to better understand our own planet's place, in our own Solar System but also among the ever-increasing number of exoplanetary systems. The VOX radio science investigation will make use of an innovative Ka-band transponder provided by the Italian Space Agency (ASI) to map the global gravity field of Venus to much finer resolution and accuracy than the current knowledge, based on the NASA Magellan mission. We will present the results of comprehensive simulations performed with the NASA GSFC orbit determination and geodetic parameter estimation software `GEODYN', based on a realistic mission scenario, tracking schedule, and high-fidelity Doppler tracking noise model. We will show how the achieved resolution and accuracy help fulfill the geophysical goals of the VOX mission, in particular through the mapping of subsurface crustal density or thickness variations that will inform the composition and origin of the tesserae and help ascertain the heat loss and importance of tectonism and subduction.

Initial observations of the nightside ionosphere of venus from pioneer venus orbiter radio occultations.

PubMed

Kliore, A J; Patel, I R; Nagy, A F; Cravens, T E; Gombosi, T I

1979-07-06

Pioneer Venus orbiter dual-frequency radio occultation measurements have produced many electron density profiles of the nightside ionosphere of Venus. Thirty-six of these profiles, measured at solar zenith angles (chi) from 90.60 degrees to 163.5 degrees , are discussed here. In the "deep" nightside ionosphere (chi > 110 degrees ), the structure and magnitude of the ionization peak are highly variable; the mean peak electron density is 16,700 +/- 7,200 (standard deviation) per cubic centimeter. In contrast, the altitude of the peak remains fairly constant with a mean of 142.2 +/- 4.1 kilometers, virtually identical to the altitude of the main peak of the dayside terminator ionosphere. The variations in the peak ionization are not directly related to contemporal variations in the solar wind speed. It is shown that electron density distributions similar to those observed in both magnitude and structure can be produced by the precipitation on the nightside of Venus of electron fluxes of about 108 per square centimeter per second with energies less than 100 electron volts. This mechanism could very likely be responsible for the maintenance of the persistent nightside ionosphere of Venus, although transport processes may also be important.

Giant radiating dyke swarms on Earth and Venus

NASA Technical Reports Server (NTRS)

Ernst, Richard E.; Head, James W.; Parfitt, Elisabeth; Wilson, Lionel; Grosfils, Eric

1993-01-01

On Earth, giant radiating dyke swarms are usually preserved as fan-shaped fragments which have been dismembered from their original configuration by subsequent plate tectonic rifting events. Analysis of the largest fragments and consideration of their original configuration has led to the idea that many swarms are plume related, and that dyke swarms radiate away from plume centers. Magellan radar data reveal abundant intact giant radiating swarms on Venus which are similar in scale and pattern to those on Earth. The absence of intense weathering and plate tectonic processes on Venus accounts for the preservation of the primary radiating patterns. It is characteristic of both Earth and Venus that giant radiating dikes are emplaced laterally for distances of at least 2000 km away from plume centers. At distances beyond the influence of the plume on both Earth and Venus, the radiating dyke pattern is often swept into a linear pattern aligned with the regional stress field. There is tremendous potential synergism between the characterization and analysis of terrestrial dyke swarms (where significant erosion has revealed their structure and emplacement directions at depth) and the giant swarms of Venus (where the complete circumferential structure is preserved, and the surface fracture systems above near surface dikes and the nature of the central source regions are revealed). In this study, we report on the characteristics of radial dyke swarms on Earth and Venus and draw some preliminary comparisons from the two perspectives. In summary, on both planets there is evidence for plume-related magmatic centers associated with vertical and lateral injection of magma over considerable distances (up to at least 2000 km). The abundance of very broadly radiating swarms on Venus supports the notion that the swarms on Earth were radiating over broad sectors at the time of intrusion but were dissected by later events. The Venus data show that a swarm can change from radiating (proximal) to regional (distal) subparallel orientations. An implication for Earth is that many regional linear swarms which do not have a radiating pattern may be due to fragmentation of the swarm during later plate tectonic rifting. Completion of the global classification and census of Venus features, comparison to the terrestrial synthesis, and documentation of the mode of emplacement of dikes in these environments (buffered and unbuffered conditions) should lead to additional general insight into mechanisms of formation and evolution and their relation to plumes.

Regional tectonic analysis of Venus as part of the Pioneer Venus guest investigator project

NASA Technical Reports Server (NTRS)

Williams, David R.

1991-01-01

Over the past year, much of the tectonic analysis of Venus we have done has centered on global properties of the planet, in order to understand fundamental aspects of the dynamics of the mantle and lithosphere of Venus. We have developed convection models of the Earth and Venus. These models assume whole mantle internally-heated convection. The viscosity is temperature, volatile-content, and stress dependent. An initial temperature and volatile content is assumed, and the thermal evolution is tracked for 4.6 billion years. During this time, heating occurs by decay of radiogenic elements in the mantle, and degassing and regassing of volatiles takes place at the surface. For a model assuming plate tectonics as the primary heat loss mechanism, representing the Earth through most of it's history and perhaps Venus' earlier history, degassing of the mantle was found to occur rapidly (approximately 200 My) over a large range of parameters. Even for parameters chosen to represent extreme cases of an initially cool planet, low radiogenic heating, and large initial volatile complement, the mantle water content was degassed to an equilibrium value in about 2 By. These values may be applicable to the early Venus, if a large, Moon-forming impact on Earth resulted in efficient heating and loss of water, leaving Venus with a comparably greater volatile budget and less vigorous early convection. It may therefore be impossible to retain large amounts of water in the interior of Venus until the planet cools down enough for the 'cold-trap' effect to take place. This effect traps crust forming melts within the mantle due to a cusp in the solidus, causing these melts to refreeze at depth into a dense eclogite phase, which will inhibit ascent of this material to the surface. This effect, however, requires a hydrous mantle, so early loss of water might prevent it from taking place. Since without plate tectonics there is no mechanism for regassing volatiles into the mantle, as occurs on Earth at subduction zones, this means the interior of Venus would at present be almost completely dry. We have also calculated argon degassing, and mantle flow velocities. viscosities, and cooling rates in these models, and these values can provide constraints on present day mantle dynamics.

Monitoring environmental change with color slides

Treesearch

Arthur W. Magill

1989-01-01

Monitoring human impact on outdoor recreation sites and view landscapes is necessary to evaluate influences which may require corrective action and to determine if management is achieving desired goals. An inexpensive method to monitor environmental change is to establish camera points and use repeat color slides. Successful monitoring from slides requires the observer...

Characterization of a multi-user indoor positioning system based on low cost depth vision (Kinect) for monitoring human activity in a smart home.

PubMed

Sevrin, Loïc; Noury, Norbert; Abouchi, Nacer; Jumel, Fabrice; Massot, Bertrand; Saraydaryan, Jacques

2015-01-01

An increasing number of systems use indoor positioning for many scenarios such as asset tracking, health care, games, manufacturing, logistics, shopping, and security. Many technologies are available and the use of depth cameras is becoming more and more attractive as this kind of device becomes affordable and easy to handle. This paper contributes to the effort of creating an indoor positioning system based on low cost depth cameras (Kinect). A method is proposed to optimize the calibration of the depth cameras, to describe the multi-camera data fusion and to specify a global positioning projection to maintain the compatibility with outdoor positioning systems. The monitoring of the people trajectories at home is intended for the early detection of a shift in daily activities which highlights disabilities and loss of autonomy. This system is meant to improve homecare health management at home for a better end of life at a sustainable cost for the community.

Monitoring the Status and Trends of Tropical Forest Terrestrial Vertebrate Communities from Camera Trap Data: A Tool for Conservation

PubMed Central

Ahumada, Jorge A.; Hurtado, Johanna; Lizcano, Diego

2013-01-01

Reducing the loss of biodiversity is key to ensure the future well being of the planet. Indicators to measure the state of biodiversity should come from primary data that are collected using consistent field methods across several sites, longitudinal, and derived using sound statistical methods that correct for observation/detection bias. In this paper we analyze camera trap data collected between 2008 and 2012 at a site in Costa Rica (Volcan Barva transect) as part of an ongoing tropical forest global monitoring network (Tropical Ecology Assessment and Monitoring Network). We estimated occupancy dynamics for 13 species of mammals, using a hierarchical modeling approach. We calculated detection-corrected species richness and the Wildlife Picture Index, a promising new indicator derived from camera trap data that measures changes in biodiversity from the occupancy estimates of individual species. Our results show that 3 out of 13 species showed significant declines in occupancy over 5 years (lowland paca, Central American agouti, nine-banded armadillo). We hypothesize that hunting, competition and/or increased predation for paca and agouti might explain these patterns. Species richness and the Wildlife Picture Index are relatively stable at the site, but small herbivores that are hunted showed a decline in diversity of about 25%. We demonstrate the usefulness of longitudinal camera trap deployments coupled with modern statistical methods and advocate for the use of this approach in monitoring and developing global and national indicators for biodiversity change. PMID:24023898

A Camera and Multi-Sensor Automated Station Design for Polar Physical and Biological Systems Monitoring: AMIGOS

NASA Astrophysics Data System (ADS)

Bohlander, J. A.; Ross, R.; Scambos, T.; Haran, T. M.; Bauer, R. J.

2012-12-01

The Automated Meteorology - Ice/Indigenous species - Geophysics Observation System (AMIGOS) consists of a set of measurement instruments and camera(s) controlled by a single-board computer with a simplified Linux operating system and an Iridium satellite modem supporting two-way communication. Primary features of the system relevant to polar operations are low power requirements, daily data uploading, reprogramming, tolerance for low temperatures, and various approaches for automatic resets and recovery from low power or cold shut-down. Instruments include a compact weather station, C/A or dual-frequency GPS, solar flux and reflectivity sensors, sonic snow gages, simplified radio-echo-sounder, and resistance thermometer string in the firn column. In the current state of development, there are two basic designs. One is intended for in situ observations of glacier conditions. The other design supports a high-resolution camera for monitoring biological or geophysical systems from short distances (100 m to 20 km). The stations have been successfully used in several locations for operational support, monitoring rapid ice changes in response to climate change or iceberg drift, and monitoring penguin colony activity. As of June, 2012, there are 9 AMIGOS systems installed, all on the Antarctic continent. The stations are a working prototype for a planned series of upgraded stations, currently termed 'Sentinels'. These stations would carry further instrumentation, communications, and processing capability to investigate ice - ocean interaction from ice tongue, ice shelf, or fjord coastline areas.

Nature of the Venus thermosphere derived from satellite drag measurements (solicited paper)

NASA Astrophysics Data System (ADS)

Keating, G.; Theriot, M.; Bougher, S.

2008-09-01

From drag measurements obtained by Pioneer Venus and Magellan, the Venus upper atmosphere was discovered to be much colder than Earth's, even though Venus is much closer to the Sun than the Earth. On the dayside, exospheric temperatures are near 300K compared to Earth's of near 1200K [1]. This is thought to result principally from 15 micron excitation of carbon dioxide by atomic oxygen resulting in very strong 15 micron emission to space, cooling off the upper atmosphere [2]. On the nightside the Venus upper atmosphere is near 100K [3], compared to Earth where temperatures are near 900K. The nightside Venus temperatures drop with altitude contrary to a thermosphere where temperatures rise with altitude. As a result, the very cold nightside is called a "cryosphere" rather than a thermosphere. This is the first cryosphere discovered in the solar system [1]. Temperatures sharply drop near the terminator. Apparently, heat is somehow blocked near the terminator from being significantly transported to the nightside [4]. Recently, drag studies were performed on a number of Earth satellites to establish whether the rise of carbon dioxide on Earth was cooling the Earth's thermosphere similar to the dayside of Venus. Keating et al. [5] discovered that a 10 percent drop in density near 350km at solar minimum occurred globally over a period of 20 years with a 10 per cent rise in carbon dioxide. This should result in about a factor of 2 decline in density from 1976 values, by the end of the 21st century brought on by thermospheric cooling. Subsequent studies have confirmed these results. Thus we are beginning to see the cooling of Earth's upper atmosphere apparently from the same process cooling the Venus thermosphere. Fig. 1 VIRA Exospheric Temperatures Atmospheric drag data from the Pioneer Venus Orbiter and Magellan were combined to generate an improved version of the Venus International Reference Atmosphere (VIRA) [6], [7]. A "fountain effect" was discovered where the atmosphere rises on the dayside producing adiabatic cooling and drops on the nightside producing some adiabatic heating. (See figure 1). The thermosphere was discovered from drag measurements to respond to the near 27-day period of the rotating Sun, for which regions of maximum solar activity reappear every 27 days. The increased euv emission from active regions increased temperatures and thermospheric density, (See Figure 2). Fig. 2 Exospheric Temperatures Compared to 10.7cm Solar Index Second diurnal survey (12/5/79 - 3/6/80) Pioneer Venus Orbiter measurements (OAD) 11 day running means [2] Estimates were also made of the response to the 11- year Solar Cycle by combining the Pioneer Venus and Magellan data. Dayside exospheric temperatures changed about 80K over the solar cycle, [8]. Earlier estimates of temperature change gave 70K based on Lyman alpha measurements. The responses to solar variability were much weaker than on Earth due apparently to the much stronger O/CO2 cooling on Venus which tended to act as a thermostat on thermospheric temperatures. Another discovery from drag measurements was the 4 to 5 day oscillation of the Venus thermosphere [3], (See figure 3). These oscillations are interpreted as resulting from the 4-day super-rotation of the atmosphere near the cloud tops. Other indications of the super-rotation of the thermosphere come from displacement of the helium bulge and atomic hydrogen bulge from midnight to near 4AM. Fig. 3 Four to Five Day Oscillations in Thermospheric Densities Magellan 1992. During 2008, the Venus Express periapsis will be dropped from 250km down to approximately 180km to allow drag measurements to be made in the North Polar Region, [9]. Drag measurements above 200km have already been obtained from both Pioneer Venus and Magellan so measurements near 180km should be accurate. In 2009, the periapsis may be decreased to a lower altitude allowing accelerometer measurements to be obtained of drag as a function of altitude, to determine density, scale height, inferred temperature, pressure, and other parameters as a function of altitude. The risk involved in the orbital decay and accelerometer measurements is minimal. We have not lost any spacecraft orbiting Venus or Mars due to unexpected thermospheric drag effects in over 30 years. The Venus Express accelerometer drag experiment is very similar to accelerometer experiments aboard Mars Global Surveyor, Mars Odyssey, and Mars Reconnaissance Orbiter which orbit Mars. The Venus Express drag measurements of the polar region will allow a global empirical model of the thermosphere to emerge. Previous drag measurements have been made principally near the equator. The experiment may help us understand on a global scale, tides, winds, gravity waves, planetary waves, and the damping of waves. Comparisons will be made between low and high latitude results; between the middle and upper atmosphere; and with other instruments that provide information from current and previous measurements. The character of the sharp temperature gradient near the day/night terminator needs to be studied at all latitudes. The cryosphere we discovered on the nightside needs to be studied at high latitudes. The rotating vortex dipole over the North Pole surrounded by a colder "collar" needs to be analyzed to identify how wave activity extends into the polar thermosphere. We have already discovered super-rotation in the equatorial thermosphere, but we need to study 4-day super-rotation at higher latitudes to obtain a global picture of the thermosphere. The super-rotation may affect escape rates and the evolution of the atmosphere. References: [1] Keating, G. M., et al: Venus Thermosphere and Exosphere: First Satellite Drag Measurements of an Extraterrestrial Atmosphere. Science, Vol. 203, No. 4382, 772-774, Feb. 23, 1979. [2] Keating, G. M. and Bougher, S.W.: Isolation of Major Venus Cooling Mechanism and Implications for Earth and Mars, Journal of Geophysical Research, Vol. 97, 4189-4197, 1992. [3] Keating, G.M.; Taylor, F.W.; Nicholson, J. V. II; and Hinson, E.W. : Short-Term Cyclic Variations and Diurnal Variations of the Venus Upper Atmosphere, Science, Vol. 205, No. 4401, 62-64, July 6, 1979. [4] Bougher, S. W.; Dickinson, R. E.; Ridley, E. C.; Roble, R. G.; Nagy, A. F.; and Cravens, T. E.: Venus mesosphere and thermosphere, II, Global circulation, temperature, and density variations, Icarus, Vol. 68, 284-312, 1986. [5] Keating, G. M. et al.: Evidence of Long-Term Global Decline in the Earth's Thermospheric Densities Apparently Related to Anthropogenic Effects, Geophysical Research Letters, Vol. 27, No. 10, 1522-1526, 2000. [6] Keating, G. M. et al.: Models of Venus Neutral Upper Atmosphere Structure and Composition: The Venus International Reference Atmosphere (Edited by A. L. Kliore, V. I. Moros, and G. M. Keating) Advances in Space Research, Vol. 5, No. 11, 117-171,1985. [7] Keating, G. M.; Hsu, N.C., and Lyu, J.: Improved Thermospheric Model for the Venus International Reference Atmosphere, Proceedings of the 31st Scientific Assembly of COSPAR, Birmingham, England, 139, 1996 (Invited) [8] Keating, G. M. and Hsu, N. C.: The Venus Atmospheric Response to Solar Cycle Variations, Geophysical Research Letters, Vol. 20, 2751-2754, 1993. [9] Keating, G.M. et al: Future drag measurements from Venus Express. Adv

Prototype of microbolometer thermal infrared camera for forest fire detection from space

NASA Astrophysics Data System (ADS)

Guerin, Francois; Dantes, Didier; Bouzou, Nathalie; Chorier, Philippe; Bouchardy, Anne-Marie; Rollin, Joël.

2017-11-01

The contribution of the thermal infrared (TIR) camera to the Earth observation FUEGO mission is to participate; to discriminate the clouds and smoke; to detect the false alarms of forest fires; to monitor the forest fires. Consequently, the camera needs a large dynamic range of detectable radiances. A small volume, low mass and power are required by the small FUEGO payload. These specifications can be attractive for other similar missions.

Distribution of sulphuric acid aerosols in the clouds and upper haze of Venus using Venus Express VAST and VeRa temperature profiles

NASA Astrophysics Data System (ADS)

Parkinson, Christopher D.; Gao, Peter; Schulte, Rick; Bougher, Stephen W.; Yung, Yuk L.; Bardeen, Charles G.; Wilquet, Valérie; Vandaele, Ann Carine; Mahieux, Arnaud; Tellmann, Silvia; Pätzold, Martin

2015-08-01

Observations from Pioneer Venus and from SPICAV/SOIR aboard Venus Express (VEx) have shown the upper haze (UH) of Venus to be highly spatially and temporally variable, and populated by multiple particle size modes. Previous models of this system (e.g., Gao et al., 2014. Icarus 231, 83-98), using a typical temperature profile representative of the atmosphere (viz., equatorial VIRA profile), did not investigate the effect of temperature on the UH particle distributions. We show that the inclusion of latitude-dependent temperature profiles for both the morning and evening terminators of Venus helps to explain how the atmospheric aerosol distributions vary spatially. In this work we use temperature profiles obtained by two instruments onboard VEx, VeRa and SPICAV/SOIR, to represent the latitudinal temperature dependence. We find that there are no significant differences between results for the morning and evening terminators at any latitude and that the cloud base moves downwards as the latitude increases due to decreasing temperatures. The UH is not affected much by varying the temperature profiles; however, the haze does show some periodic differences, and is slightly thicker at the poles than at the equator. We also find that the sulphuric acid "rain" seen in previous models may be restricted to the equatorial regions of Venus, such that the particle size distribution is relatively stable at higher latitudes and at the poles.

A New View of the Stratigraphic History of Venus

NASA Astrophysics Data System (ADS)

Guest, John E.; Stofan, Ellen R.

1999-05-01

Studies of Venus using Magellan data have so far generated two views about the way Venus has evolved. On the one hand, Venus has been suggested to have had a history in which there was a series of epochs, each represented by a different volcanic or tectonic process on a global scale (Basilevsky and Head 1995; J. W. Headet al.1996,Lunar Planet Sci. 27th, 525-526; P. T. Basilevskyet al.1997, InVenus II, Univ. of Arizona Press, Tucson). This we define as a directional history. On the other hand, there is evidence to suggest that coronae, rifts, wrinkle ridges, small and large edifices, and large flow fields have each formed throughout the portion of Venus' history revealed by presently exposed rock units. We propose that the plains have been built up by lavas erupted in a number of different styles, each occurring throughout the history represented by the exposed stratigraphy of the planet. Dates derived from crater counts accumulated from the combined area of specific types of feature such as coronae (e.g., M. H. Priceet al.1996,J. Geophys. Res.101, 4657-4672) must be interpreted with care as the method is based upon the assumption that features of like morphology have the same age. Detailed studies from full resolution Magellan data indicate that Venus has had a complex history in which most geologic processes have operated in a nondirectional fashion to a greater or lesser extent throughout the planet's history.

Effects of variation in coagulation and photochemistry parameters on the particle size distributions in the Venus clouds

NASA Astrophysics Data System (ADS)

McGouldrick, Kevin

2017-12-01

This paper explores the effects that variation in the coalescence efficiency of the Venus cloud particles can have on the structure of the Venus cloud. It is motivated by the acknowledgment of uncertainties in the measured parameters—and the assumptions made to account for them—that define our present knowledge of the particle characteristics. Specifically, we explore the consequence of allowing the coalescence efficiency of supercooled sulfuric acid in the upper clouds to tend to zero. This produces a cloud that occasionally exhibits an enhancement of small particles at altitude (similar to the upper hazes observed by Pioneer Venus and subsequently shown to be somewhat transient). This simulated cloud occasionally exhibits a rapid growth of particle size near cloud base, exhibiting characteristics similar to those seen in the controversial Mode 3 particles. These results demonstrate that a subset of the variations observed as near-infrared opacity variations in the lower and middle clouds of Venus can be explained by microphysical, in addition to dynamical, variations. Furthermore, the existence of a population of particles exhibiting less efficient coalescence efficiencies would support the likelihood of conditions suitable for charge exchange, hence lightning, in the Venus clouds. We recommend future laboratory studies on the coalescence properties of sulfuric acid under the range of conditions experienced in the Venus clouds. We also recommend future in situ measurements to better characterize the properties of the cloud particles themselves, especially composition and particle habits (shapes).[Figure not available: see fulltext.

Venus and Mars Obstacles in the Solar Wind

NASA Astrophysics Data System (ADS)

Luhmann, J. G.; Mitchell, D. L.; Acuna, M. H.; Russell, C. T.; Brecht, S. H.; Lyon, J. G.

2000-10-01

Comparisons of the magnetosheaths of Venus and Mars contrast the relative simplicity of the Venus solar wind interaction and the ``Jekyll and Hyde" nature of the Mars interaction. Magnetometer observations from Mars Global Surveyor during the elliptical science phasing orbits and Pioneer Venus Orbiter in its normally elliptical orbit are compared, with various models used to compensate for the different near-polar periapsis of MGS and near-equator periapsis of PVO. Gasdynamic or MHD fluid models of flow around a conducting sphere provide a remarkably good desciption of the Venus case, and the Mars case when the strong Martian crustal magnetic anomalies are in the flow wake. In the case of Venus, large magnetosheath field fluctuations can be reliably tied to occurrence of a subsolar quasiparallel bow shock resulting from a small interplanetary field cone angle (angle between flow and field) upstream. At Mars one must also contend with such large fluctuations from the bow shock, but also from unstable solar wind proton distributions due to finite ion gyroradius effects, and from the complicated obstacle presented to the solar wind when the crustal magnetic anomalies are on the ram face or terminator. We attempt to distinguish between these factors at Mars, which are important for interpretation of the upcoming NOZOMI and Mars Express mission measurements. The results also provide more insights into a uniquely complex type of solar system solar wind interaction involving crustal fields akin to the Moon's, combined with a Venus-like ionospheric obstacle.

Networked web-cameras monitor congruent seasonal development of birches with phenological field observations

NASA Astrophysics Data System (ADS)

Peltoniemi, Mikko; Aurela, Mika; Böttcher, Kristin; Kolari, Pasi; Loehr, John; Karhu, Jouni; Kubin, Eero; Linkosalmi, Maiju; Melih Tanis, Cemal; Nadir Arslan, Ali

2017-04-01

Ecosystems' potential to provide services, e.g. to sequester carbon is largely driven by the phenological cycle of vegetation. Timing of phenological events is required for understanding and predicting the influence of climate change on ecosystems and to support various analyses of ecosystem functioning. We established a network of cameras for automated monitoring of phenological activity of vegetation in boreal ecosystems of Finland. Cameras were mounted on 14 sites, each site having 1-3 cameras. In this study, we used cameras at 11 of these sites to investigate how well networked cameras detect phenological development of birches (Betula spp.) along the latitudinal gradient. Birches are interesting focal species for the analyses as they are common throughout Finland. In our cameras they often appear in smaller quantities within dominant species in the images. Here, we tested whether small scattered birch image elements allow reliable extraction of color indices and changes therein. We compared automatically derived phenological dates from these birch image elements to visually determined dates from the same image time series, and to independent observations recorded in the phenological monitoring network from the same region. Automatically extracted season start dates based on the change of green color fraction in the spring corresponded well with the visually interpreted start of season, and field observed budburst dates. During the declining season, red color fraction turned out to be superior over green color based indices in predicting leaf yellowing and fall. The latitudinal gradients derived using automated phenological date extraction corresponded well with gradients based on phenological field observations from the same region. We conclude that already small and scattered birch image elements allow reliable extraction of key phenological dates for birch species. Devising cameras for species specific analyses of phenological timing will be useful for explaining variation of time series of satellite based indices, and it will also benefit models describing ecosystem functioning at species or plant functional type level. With the contribution of the LIFE+ financial instrument of the European Union (LIFE12 ENV/FI/000409 Monimet, http://monimet.fmi.fi)

High spatial resolution infrared camera as ISS external experiment

NASA Astrophysics Data System (ADS)

Eckehard, Lorenz; Frerker, Hap; Fitch, Robert Alan

High spatial resolution infrared camera as ISS external experiment for monitoring global climate changes uses ISS internal and external resources (eg. data storage). The optical experiment will consist of an infrared camera for monitoring global climate changes from the ISS. This technology was evaluated by the German small satellite mission BIRD and further developed in different ESA projects. Compared to BIRD the presended instrument uses proven sensor advanced technologies (ISS external) and ISS on board processing and storage capabili-ties (internal). The instrument will be equipped with a serial interfaces for TM/TC and several relay commands for the power supply. For data processing and storage a mass memory is re-quired. The access to actual attitude data is highly desired to produce geo referenced maps-if possible by an on board processing.

What are we missing? Advantages of more than one viewpoint to estimate fish assemblages using baited video

PubMed Central

Huveneers, Charlie; Fairweather, Peter G.

2018-01-01

Counting errors can bias assessments of species abundance and richness, which can affect assessments of stock structure, population structure and monitoring programmes. Many methods for studying ecology use fixed viewpoints (e.g. camera traps, underwater video), but there is little known about how this biases the data obtained. In the marine realm, most studies using baited underwater video, a common method for monitoring fish and nekton, have previously only assessed fishes using a single bait-facing viewpoint. To investigate the biases stemming from using fixed viewpoints, we added cameras to cover 360° views around the units. We found similar species richness for all observed viewpoints but the bait-facing viewpoint recorded the highest fish abundance. Sightings of infrequently seen and shy species increased with the additional cameras and the extra viewpoints allowed the abundance estimates of highly abundant schooling species to be up to 60% higher. We specifically recommend the use of additional cameras for studies focusing on shyer species or those particularly interested in increasing the sensitivity of the method by avoiding saturation in highly abundant species. Studies may also benefit from using additional cameras to focus observation on the downstream viewpoint. PMID:29892386

Developing a multi-Kinect-system for monitoring in dairy cows: object recognition and surface analysis using wavelets.

PubMed

Salau, J; Haas, J H; Thaller, G; Leisen, M; Junge, W

2016-09-01

Camera-based systems in dairy cattle were intensively studied over the last years. Different from this study, single camera systems with a limited range of applications were presented, mostly using 2D cameras. This study presents current steps in the development of a camera system comprising multiple 3D cameras (six Microsoft Kinect cameras) for monitoring purposes in dairy cows. An early prototype was constructed, and alpha versions of software for recording, synchronizing, sorting and segmenting images and transforming the 3D data in a joint coordinate system have already been implemented. This study introduced the application of two-dimensional wavelet transforms as method for object recognition and surface analyses. The method was explained in detail, and four differently shaped wavelets were tested with respect to their reconstruction error concerning Kinect recorded depth maps from different camera positions. The images' high frequency parts reconstructed from wavelet decompositions using the haar and the biorthogonal 1.5 wavelet were statistically analyzed with regard to the effects of image fore- or background and of cows' or persons' surface. Furthermore, binary classifiers based on the local high frequencies have been implemented to decide whether a pixel belongs to the image foreground and if it was located on a cow or a person. Classifiers distinguishing between image regions showed high (⩾0.8) values of Area Under reciever operation characteristic Curve (AUC). The classifications due to species showed maximal AUC values of 0.69.

Preliminary Study of UAS Equipped with Thermal Camera for Volcanic Geothermal Monitoring in Taiwan

PubMed Central

Chio, Shih-Hong; Lin, Cheng-Horng

2017-01-01

Thermal infrared cameras sense the temperature information of sensed scenes. With the development of UASs (Unmanned Aircraft Systems), thermal infrared cameras can now be carried on a quadcopter UAV (Unmanned Aircraft Vehicle) to appropriately collect high-resolution thermal images for volcanic geothermal monitoring in a local area. Therefore, the quadcopter UAS used to acquire thermal images for volcanic geothermal monitoring has been developed in Taiwan as part of this study to overcome the difficult terrain with highly variable topography and extreme environmental conditions. An XM6 thermal infrared camera was employed in this thermal image collection system. The Trimble BD970 GNSS (Global Navigation Satellite System) OEM (Original Equipment Manufacturer) board was also carried on the quadcopter UAV to gather dual-frequency GNSS observations in order to determine the flying trajectory data by using the Post-Processed Kinematic (PPK) technique; this will be used to establish the position and orientation of collected thermal images with less ground control points (GCPs). The digital surface model (DSM) and thermal orthoimages were then produced from collected thermal images. Tests conducted in the Hsiaoyukeng area of Taiwan’s Yangmingshan National Park show that the difference between produced DSM and airborne LIDAR (Light Detection and Ranging) data are about 37% between −1 m and 1 m, and 66% between −2 m and 2 m in the area surrounded by GCPs. As the accuracy of thermal orthoimages is about 1.78 m, it is deemed sufficient for volcanic geothermal monitoring. In addition, the thermal orthoimages show some phenomena not only more globally than do the traditional methods for volcanic geothermal monitoring, but they also show that the developed system can be further employed in Taiwan in the future. PMID:28718790

Preliminary Study of UAS Equipped with Thermal Camera for Volcanic Geothermal Monitoring in Taiwan.

PubMed

Chio, Shih-Hong; Lin, Cheng-Horng

2017-07-18

Thermal infrared cameras sense the temperature information of sensed scenes. With the development of UASs (Unmanned Aircraft Systems), thermal infrared cameras can now be carried on a quadcopter UAV (Unmanned Aircraft Vehicle) to appropriately collect high-resolution thermal images for volcanic geothermal monitoring in a local area. Therefore, the quadcopter UAS used to acquire thermal images for volcanic geothermal monitoring has been developed in Taiwan as part of this study to overcome the difficult terrain with highly variable topography and extreme environmental conditions. An XM6 thermal infrared camera was employed in this thermal image collection system. The Trimble BD970 GNSS (Global Navigation Satellite System) OEM (Original Equipment Manufacturer) board was also carried on the quadcopter UAV to gather dual-frequency GNSS observations in order to determine the flying trajectory data by using the Post-Processed Kinematic (PPK) technique; this will be used to establish the position and orientation of collected thermal images with less ground control points (GCPs). The digital surface model (DSM) and thermal orthoimages were then produced from collected thermal images. Tests conducted in the Hsiaoyukeng area of Taiwan's Yangmingshan National Park show that the difference between produced DSM and airborne LIDAR (Light Detection and Ranging) data are about 37% between -1 m and 1 m, and 66% between -2 m and 2 m in the area surrounded by GCPs. As the accuracy of thermal orthoimages is about 1.78 m, it is deemed sufficient for volcanic geothermal monitoring. In addition, the thermal orthoimages show some phenomena not only more globally than do the traditional methods for volcanic geothermal monitoring, but they also show that the developed system can be further employed in Taiwan in the future.

PBF (PER620) north facade. Camera facing south. Small metal shed ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF (PER-620) north facade. Camera facing south. Small metal shed at right is Stack Gas Monitor Building, PER-629. Date: March 2004. INEEL negative no. HD-41-2-4 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

Pioneer Venus observations during Comet Halley's inferior conjunction

NASA Technical Reports Server (NTRS)

Russell, C. T.; Luhmann, J. G.; Scarf, F. L.

1985-01-01

On Feb. 4, 1986, Halley passed through inferior conjunction with Venus but was at high latitudes. Not all data for this time period have been received. However, the data that are available suggest that at most only weak effects associated with Halley were seen at Pioneer Venus. The data during this time, however, are useful for correlating with the behavior of the plasma tail.

Plate tectonics on Venus

NASA Technical Reports Server (NTRS)

Anderson, D. L.

1981-01-01

The high surface temperature of Venus implies a permanently buoyant lithosphere and a thick basaltic crust. Terrestrial-style tectonics with deep subduction and crustal recycling is not possible. Overthickened basaltic crust partially melts instead of converting to eclogite. Because mantle magmas do not have convenient access to the surface the Ar-40 abundance in the atmosphere should be low. Venus may provide an analog to Archean tectonics on the earth.

Hybrid simulations of Venus' ionospheric magnetization states

NASA Astrophysics Data System (ADS)

Wiehle, Stefan; Motschmann, Uwe; Fränz, Markus

2013-04-01

The solar wind interaction with the plasma environment of Venus is studied with focus on ionospheric magnetization states using a 3D hybrid simulation code. The plasma environment of Venus was investigated mainly by Pioneer Venus Orbiter (PVO) and the still ongoing Venus Express (VEX) mission. Unlike many other planets, Venus' ionosphere is not shielded by a strong magnetosphere. Hence, data measured by spacecraft like PVO and VEX close to the planet are highly sensitive to solar wind and IMF upstream conditions, which cannot be measured while the spacecraft is inside the magnetosheath region about one hour before and after the closest approach. However, solar wind and IMF are known to change within minutes; ionospheric magnetization states, found by PVO and VEX, are highly dependent on the solar wind upstream pressure and also the magnetic field direction may change rapidly in case of a magnetic sector boundary crossing. When these solar wind induced transition effects occur, the causal change in the solar wind cannot be determined from ionospheric in-situ data. Additionally, with an orbital period of 24 hours, measuring transition timescales of solar wind triggered events is not possible. Our self-consistent simulations aim to provide a global picture of the solar wind interaction with Venus focusing on the effects of upstream fluctuations to the magnetic field in the vicinity of the planet. We use the A.I.K.E.F. (Adaptive Ion Kinetic Electron Fluid) 3D hybrid simulation code to model the entire Venus plasma environment. The simulation grid is refined within the ionosphere in order to resolve strong small-scale gradients of the magnetic field and ion density, a necessity to describe the magnetic field depletion inside the Venus' ionosphere. In contrast to other simulation studies, we apply no boundary conditions for the magnetic field at the planetary surface. Furthermore, we include varying upstream conditions like solar wind velocity and density as well as IMF strength and direction by adjusting these parameters after a first, quasi-stationary state has been reached. This allows for a simulation of dynamic processes like the transition between the magnetized and unmagnetized ionospheric state and fossil fields.

Eye gaze tracking for endoscopic camera positioning: an application of a hardware/software interface developed to automate Aesop.

PubMed

Ali, S M; Reisner, L A; King, B; Cao, A; Auner, G; Klein, M; Pandya, A K

2008-01-01

A redesigned motion control system for the medical robot Aesop allows automating and programming its movements. An IR eye tracking system has been integrated with this control interface to implement an intelligent, autonomous eye gaze-based laparoscopic positioning system. A laparoscopic camera held by Aesop can be moved based on the data from the eye tracking interface to keep the user's gaze point region at the center of a video feedback monitor. This system setup provides autonomous camera control that works around the surgeon, providing an optimal robotic camera platform.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, while Greg Harlow, with United Space Alliance (USA) (above) threads a camera under the tiles of the orbiter Endeavour, Peggy Ritchie, USA, (behind the stand) and NASA’s Richard Parker (seated) watch the images on a monitor to inspect for corrosion.

NASA Image and Video Library

2003-09-04

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, while Greg Harlow, with United Space Alliance (USA) (above) threads a camera under the tiles of the orbiter Endeavour, Peggy Ritchie, USA, (behind the stand) and NASA’s Richard Parker (seated) watch the images on a monitor to inspect for corrosion.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, while Greg Harlow, with United Space Alliance (USA), (above) threads a camera under the tiles of the orbiter Endeavour, NASA’s Richard Parker (below left) and Peggy Ritchie, with USA, (at right) watch the images on a monitor to inspect for corrosion.

NASA Image and Video Library

2003-09-04

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, while Greg Harlow, with United Space Alliance (USA), (above) threads a camera under the tiles of the orbiter Endeavour, NASA’s Richard Parker (below left) and Peggy Ritchie, with USA, (at right) watch the images on a monitor to inspect for corrosion.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, while Greg Harlow, with United Space Alliance (USA), (above) threads a camera under the tiles of the orbiter Endeavour, Peggy Ritchie, with USA, (behind the stand) and NASA’s Richard Parker watch the images on a monitor to inspect for corrosion.

NASA Image and Video Library

2003-09-04

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, while Greg Harlow, with United Space Alliance (USA), (above) threads a camera under the tiles of the orbiter Endeavour, Peggy Ritchie, with USA, (behind the stand) and NASA’s Richard Parker watch the images on a monitor to inspect for corrosion.

Dynamic interpretation of geoid anomalies

NASA Technical Reports Server (NTRS)

Hager, Bradford H.

1988-01-01

The NASA Geodynamics program has as two of its missions precise determination of spatial variations in earth's geopotential (or geoid) and highly accurate monitoring of polar motion, including changes in the length of day (LOD). For the past several years, data sets provided by NASA, along with data and models from other areas of geophysic were used to place fundamental contraints on the large scale dynamics of earth and her sister planet Venus. The main approach was using fluid mechanical models of mantle flow to predict the long-wavelength variations in the geoid.

Camera traps can be heard and seen by animals.

PubMed

Meek, Paul D; Ballard, Guy-Anthony; Fleming, Peter J S; Schaefer, Michael; Williams, Warwick; Falzon, Greg

2014-01-01

Camera traps are electrical instruments that emit sounds and light. In recent decades they have become a tool of choice in wildlife research and monitoring. The variability between camera trap models and the methods used are considerable, and little is known about how animals respond to camera trap emissions. It has been reported that some animals show a response to camera traps, and in research this is often undesirable so it is important to understand why the animals are disturbed. We conducted laboratory based investigations to test the audio and infrared optical outputs of 12 camera trap models. Camera traps were measured for audio outputs in an anechoic chamber; we also measured ultrasonic (n = 5) and infrared illumination outputs (n = 7) of a subset of the camera trap models. We then compared the perceptive hearing range (n = 21) and assessed the vision ranges (n = 3) of mammals species (where data existed) to determine if animals can see and hear camera traps. We report that camera traps produce sounds that are well within the perceptive range of most mammals' hearing and produce illumination that can be seen by many species.

Numerical Simulations of Mass Loading in the Solar Wind Interaction with Venus

NASA Technical Reports Server (NTRS)

Murawski, K.; Steinolfson, R. S.

1996-01-01

Numerical simulations are performed in the framework of nonlinear two-dimensional magnetohydrodynamics to investigate the influence of mass loading on the solar wind interaction with Venus. The principal physical features of the interaction of the solar wind with the atmosphere of Venus are presented. The formation of the bow shock, the magnetic barrier, and the magnetotail are some typical features of the interaction. The deceleration of the solar wind due to the mass loading near Venus is an additional feature. The effect of the mass loading is to push the shock farther outward from the planet. The influence of different values of the magnetic field strength on plasma evolution is considered.