241. BUILDINGS 455, 456, 509, 510 AND 457 (CELESTIAL NAVIGATION ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

241. BUILDINGS 455, 456, 509, 510 AND 457 (CELESTIAL NAVIGATION COMPLEX), 1942-43. BUREAU OF YARDS AND DOCKS STANDARD PLANS. VIEW NORTH ACROSS WASP ST. SHOWING THE 4 TRAINING SILOS FROM LEFT TO RIGHT: BUILDINGS 455, 456, 509, AND 510; AND, BESIDE THEM, BUILDING 457. - Quonset Point Naval Air Station, Roger Williams Way, North Kingstown, Washington County, RI

Relative Navigation of Formation-Flying Satellites

NASA Technical Reports Server (NTRS)

Long, Anne; Kelbel, David; Lee, Taesul; Leung, Dominic; Carpenter, J. Russell; Grambling, Cheryl

2002-01-01

This paper compares autonomous relative navigation performance for formations in eccentric, medium and high-altitude Earth orbits using Global Positioning System (GPS) Standard Positioning Service (SPS), crosslink, and celestial object measurements. For close formations, the relative navigation accuracy is highly dependent on the magnitude of the uncorrelated measurement errors. A relative navigation position accuracy of better than 10 centimeters root-mean-square (RMS) can be achieved for medium-altitude formations that can continuously track at least one GPS signal. A relative navigation position accuracy of better than 15 meters RMS can be achieved for high-altitude formations that have sparse tracking of the GPS signals. The addition of crosslink measurements can significantly improve relative navigation accuracy for formations that use sparse GPS tracking or celestial object measurements for absolute navigation.

Celestial Navigation in the USA, Fiji, and Tunisia

NASA Astrophysics Data System (ADS)

Holbrook, Jarita C.

2015-05-01

Today there are many coastal communities that are home to navigators who use stars for position finding at night; I was, however, unaware of this fact when I began researching celestial navigation practices in 1997. My project focused on three communities: the Moce Islanders of Fiji, the Kerkennah Islanders in Tunisia, and the U.S. Navy officers and students at the United States Naval Academy, Annapolis, Maryland. My goal was to answer the question of why people continue to navigate by the stars, but also to understand the role of technology in their navigation practices. Using anthropology techniques of ethnography including participant observation, formal and informal interviews, audio and videotaping, I gathered data over five years at the three communities. I began by learning the details of how they use the stars for navigation. Next, I learned about who did the navigation and where they learned to navigate. I gathered opinions on various navigation aids and instruments, and opinions about the future of using the stars for navigation. I listened to the stories that they told about navigating. In the United States I worked in English, in Fiji, in Fijian and English, and in Tunisia, French and English. For the formal interviews I worked with translators. The navigators use stars for navigating today but the future of their techniques is not certain. Though practiced today, these celestial navigation traditions have undergone and continue to undergo changes. New navigational technologies are part of the stimulation for change, thus 'a meeting of different worlds' is symbolized by peoples encounters with these technologies.

Vector navigation in desert ants, Cataglyphis fortis: celestial compass cues are essential for the proper use of distance information.

PubMed

Sommer, Stefan; Wehner, Rüdiger

2005-10-01

Foraging desert ants navigate primarily by path integration. They continually update homing direction and distance by employing a celestial compass and an odometer. Here we address the question of whether information about travel distance is correctly used in the absence of directional information. By using linear channels that were partly covered to exclude celestial compass cues, we were able to test the distance component of the path-integration process while suppressing the directional information. Our results suggest that the path integrator cannot process the distance information accumulated by the odometer while ants are deprived of celestial compass information. Hence, during path integration directional cues are a prerequisite for the proper use of travel-distance information by ants.

Satellite Ephemeris Correction via Remote Site Observation for Star Tracker Navigation Performance Improvement

DTIC Science & Technology

2016-03-01

squared RMS root mean squared GCRF Geocentric Celestial Reference Frame xi List of Figures Figure Page 1 Geometry of single observation...RA and DEC in the celestial sphere. The Geocentric Celestial Reference Frame (GCRF) is the standard geocentric frame that measures the RA east in the...Figure 2. Right ascension (α) and declination (δ) in the celestial sphere[6] 7 made between geocentric and topocentric angles. Geocentric is referred to

A novel navigation method used in a ballistic missile

NASA Astrophysics Data System (ADS)

Qian, Hua-ming; Sun, Long; Cai, Jia-nan; Peng, Yu

2013-10-01

The traditional strapdown inertial/celestial integrated navigation method used in a ballistic missile cannot accurately estimate the accelerometer bias. It might cause a divergence of navigation errors. To solve this problem, a new navigation method named strapdown inertial/starlight refractive celestial integrated navigation is proposed. To verify the feasibility of the proposed method, a simulated program of a ballistic missile is presented. The simulation results indicated that, when multiple refraction stars are used, the proposed method can accurately estimate the accelerometer bias, and suppress the divergence of navigation errors completely. Specifically, in order to apply this method to a ballistic missile, a novel measurement equation based on stellar refraction was developed. Furthermore a method to calculate the number of refraction stars observed by the stellar sensor was given. Finally, the relationship between the number of refraction stars used and the navigation accuracy is analysed.

Method and System for Gamma-Ray Localization Induced Spacecraft Navigation Using Celestial Gamma-Ray Sources

NASA Technical Reports Server (NTRS)

Hisamoto, Chuck (Inventor); Arzoumanian, Zaven (Inventor); Sheikh, Suneel I. (Inventor)

2015-01-01

A method and system for spacecraft navigation using distant celestial gamma-ray bursts which offer detectable, bright, high-energy events that provide well-defined characteristics conducive to accurate time-alignment among spatially separated spacecraft. Utilizing assemblages of photons from distant gamma-ray bursts, relative range between two spacecraft can be accurately computed along the direction to each burst's source based upon the difference in arrival time of the burst emission at each spacecraft's location. Correlation methods used to time-align the high-energy burst profiles are provided. The spacecraft navigation may be carried out autonomously or in a central control mode of operation.

Use of Reference Frames for Interplanetary Navigation at JPL

NASA Technical Reports Server (NTRS)

Heflin, Michael; Jacobs, Chris; Sovers, Ojars; Moore, Angelyn; Owen, Sue

2010-01-01

Navigation of interplanetary spacecraft is typically based on range, Doppler, and differential interferometric measurements made by ground-based telescopes. Acquisition and interpretation of these observations requires accurate knowledge of the terrestrial reference frame and its orientation with respect to the celestial frame. Work is underway at JPL to reprocess historical VLBI and GPS data to improve realizations of the terrestrial and celestial frames. Improvements include minimal constraint alignment, improved tropospheric modeling, better orbit determination, and corrections for antenna phase center patterns.

Sensory bases of navigation.

PubMed

Gould, J L

1998-10-08

Navigating animals need to know both the bearing of their goal (the 'map' step), and how to determine that direction (the 'compass' step). Compasses are typically arranged in hierarchies, with magnetic backup as a last resort when celestial information is unavailable. Magnetic information is often essential to calibrating celestial cues, though, and repeated recalibration between celestial and magnetic compasses is important in many species. Most magnetic compasses are based on magnetite crystals, but others make use of induction or paramagnetic interactions between short-wavelength light and visual pigments. Though odors may be used in some cases, most if not all long-range maps probably depend on magnetite. Magnetitebased map senses are used to measure only latitude in some species, but provide the distance and direction of the goal in others.

Optimization design about gimbal structure of high-precision autonomous celestial navigation tracking mirror system

NASA Astrophysics Data System (ADS)

Huang, Wei; Yang, Xiao-xu; Han, Jun-feng; Wei, Yu; Zhang, Jing; Xie, Mei-lin; Yue, Peng

2016-01-01

High precision tracking platform of celestial navigation with control mirror servo structure form, to solve the disadvantages of big volume and rotational inertia, slow response speed, and so on. It improved the stability and tracking accuracy of platform. Due to optical sensor and mirror are installed on the middle-gimbal, stiffness and resonant frequency requirement for high. Based on the application of finite element modality analysis theory, doing Research on dynamic characteristics of the middle-gimbal, and ANSYS was used for the finite element dynamic emulator analysis. According to the result of the computer to find out the weak links of the structure, and Put forward improvement suggestions and reanalysis. The lowest resonant frequency of optimization middle-gimbal avoid the bandwidth of the platform servo mechanism, and much higher than the disturbance frequency of carrier aircraft, and reduces mechanical resonance of the framework. Reaching provides a theoretical basis for the whole machine structure optimization design of high-precision of autonomous Celestial navigation tracking mirror system.

Investigation on navigation patterns of inertial/celestial integrated systems

NASA Astrophysics Data System (ADS)

Luo, Dacheng; Liu, Yan; Liu, Zhiguo; Jiao, Wei; Wang, Qiuyan

2014-11-01

It is known that Strapdown Inertial Navigation System (SINS), Global Navigation Satellite System (GNSS) and Celestial Navigation System (CNS) can complement each other's advantages. The SINS/CNS integrated system, which has the characteristics of strong autonomy, high accuracy and good anti-jamming, is widely used in military and civilian applications. Similar to SINS/GNSS integrated system, the SINS/CNS integrated system can also be divided into three kinds according to the difference of integrating depth, i.e., loosely coupled pattern, tightly coupled pattern and deeply coupled pattern. In this paper, the principle and characteristics of each pattern of SINS/CNS system are analyzed. Based on the comparison of these patterns, a novel deeply coupled SINS/CNS integrated navigation scheme is proposed. The innovation of this scheme is that a new star pattern matching method aided by SINS information is put forward. Thus the complementary features of these two subsystems are reflected.

Technologies Old and New: Teaching Ancient Navigation.

ERIC Educational Resources Information Center

Spalding, Simon

1995-01-01

One educator presents maritime history to students using technologies available to ancient seafarers. Techniques include dead reckoning, the sandglass, the magnetic compass, celestial navigation, and various navigation techniques of precontact Polynesia that depended upon oral transmission of knowledge. The paper notes differences between…

It All Depends on Your Attitude.

ERIC Educational Resources Information Center

Kastner, Bernice

1992-01-01

Presents six learning exercises that introduce students to the mathematics used to control and track spacecraft attitude. Describes the geocentric system used for Earthbound location and navigation, the celestial sphere, the spacecraft-based celestial system, time-dependent angles, observer-fixed coordinate axes, and spacecraft rotational axes.…

Ocelli contribute to the encoding of celestial compass information in the Australian desert ant Melophorus bagoti.

PubMed

Schwarz, Sebastian; Albert, Laurence; Wystrach, Antoine; Cheng, Ken

2011-03-15

Many animal species, including some social hymenoptera, use the visual system for navigation. Although the insect compound eyes have been well studied, less is known about the second visual system in some insects, the ocelli. Here we demonstrate navigational functions of the ocelli in the visually guided Australian desert ant Melophorus bagoti. These ants are known to rely on both visual landmark learning and path integration. We conducted experiments to reveal the role of ocelli in the perception and use of celestial compass information and landmark guidance. Ants with directional information from their path integration system were tested with covered compound eyes and open ocelli on an unfamiliar test field where only celestial compass cues were available for homing. These full-vector ants, using only their ocelli for visual information, oriented significantly towards the fictive nest on the test field, indicating the use of celestial compass information that is presumably based on polarised skylight, the sun's position or the colour gradient of the sky. Ants without any directional information from their path-integration system (zero-vector) were tested, also with covered compound eyes and open ocelli, on a familiar training field where they have to use the surrounding panorama to home. These ants failed to orient significantly in the homeward direction. Together, our results demonstrated that M. bagoti could perceive and process celestial compass information for directional orientation with their ocelli. In contrast, the ocelli do not seem to contribute to terrestrial landmark-based navigation in M. bagoti.

Navigation Concepts for the James Webb Space Telescope

NASA Technical Reports Server (NTRS)

Long, Anne; Leung, Dominic; Kelbel, David; Beckman, Mark; Grambling, Cheryl

2003-01-01

This paper evaluates the performance that can be achieved using candidate ground and onboard navigation approaches for operation of the James Webb Space Telescope, which will be in an orbit about the Sun-Earth L2 libration point. The ground navigation approach processes standard range and Doppler measurements from the Deep Space Network The onboard navigation approach processes celestial object measurements and/or ground-to- spacecraft Doppler measurements to autonomously estimate the spacecraft s position and velocity and Doppler reference frequency. Particular attention is given to assessing the absolute position and velocity accuracy that can be achieved in the presence of the frequent spacecraft reorientations and momentum unloads planned for this mission. The ground navigation approach provides stable navigation solutions using a tracking schedule of one 30-minute contact per day. The onboard navigation approach that uses only optical quality celestial object measurements provides stable autonomous navigation solutions. This study indicates that unmodeled changes in the solar radiation pressure cross-sectional area and modeled momentum unload velocity changes are the major error sources. These errors can be mitigated by modeling these changes, by estimating corrections to compensate for the changes, or by including acceleration measurements.

A novel interplanetary optical navigation algorithm based on Earth-Moon group photos by Chang'e-5T1 probe

NASA Astrophysics Data System (ADS)

Bu, Yanlong; Zhang, Qiang; Ding, Chibiao; Tang, Geshi; Wang, Hang; Qiu, Rujin; Liang, Libo; Yin, Hejun

2017-02-01

This paper presents an interplanetary optical navigation algorithm based on two spherical celestial bodies. The remarkable characteristic of the method is that key navigation parameters can be estimated depending entirely on known sizes and ephemerides of two celestial bodies, especially positioning is realized through a single image and does not rely on traditional terrestrial radio tracking any more. Actual Earth-Moon group photos captured by China's Chang'e-5T1 probe were used to verify the effectiveness of the algorithm. From 430,000 km away from the Earth, the camera pointing accuracy reaches 0.01° (one sigma) and the inertial positioning error is less than 200 km, respectively; meanwhile, the cost of the ground control and human resources are greatly reduced. The algorithm is flexible, easy to implement, and can provide reference to interplanetary autonomous navigation in the solar system.

Research of autonomous celestial navigation based on new measurement model of stellar refraction

NASA Astrophysics Data System (ADS)

Yu, Cong; Tian, Hong; Zhang, Hui; Xu, Bo

2014-09-01

Autonomous celestial navigation based on stellar refraction has attracted widespread attention for its high accuracy and full autonomy．In this navigation method, establishment of accurate stellar refraction measurement model is the fundament and key issue to achieve high accuracy navigation. However, the existing measurement models are limited due to the uncertainty of atmospheric parameters. Temperature, pressure and other factors which affect the stellar refraction within the height of earth's stratosphere are researched, and the varying model of atmosphere with altitude is derived on the basis of standard atmospheric data. Furthermore, a novel measurement model of stellar refraction in a continuous range of altitudes from 20 km to 50 km is produced by modifying the fixed altitude (25 km) measurement model, and equation of state with the orbit perturbations is established, then a simulation is performed using the improved Extended Kalman Filter. The results show that the new model improves the navigation accuracy, which has a certain practical application value.

Polarization transition between sunlit and moonlit skies with possible implications for animal orientation and Viking navigation: anomalous celestial twilight polarization at partial moon.

PubMed

Barta, András; Farkas, Alexandra; Száz, Dénes; Egri, Ádám; Barta, Pál; Kovács, József; Csák, Balázs; Jankovics, István; Szabó, Gyula; Horváth, Gábor

2014-08-10

Using full-sky imaging polarimetry, we measured the celestial distribution of polarization during sunset and sunrise at partial (78% and 72%) and full (100%) moon in the red (650 nm), green (550 nm), and blue (450 nm) parts of the spectrum. We investigated the temporal change of the patterns of degree p and angle α of linear polarization of sunlit and moonlit skies at dusk and dawn. We describe here the position change of the neutral points of sky polarization, and present video clips about the celestial polarization transition at moonlit twilight. We found that at partial moon and at a medium latitude (47° 15.481' N) during this transition there is a relatively short (10-20 min) period when (i) the maximum of p of skylight decreases, and (ii) from the celestial α pattern neither the solar-antisolar nor the lunar-antilunar meridian can be unambiguously determined. These meridians can serve as reference directions of animal orientation and Viking navigation based on sky polarization. The possible influence of these atmospheric optical phenomena during the polarization transition between sunlit and moonlit skies on the orientation of polarization-sensitive crepuscular/nocturnal animals and the hypothesized navigation of sunstone-aided Viking seafarers is discussed.

Relative Navigation of Formation Flying Satellites

NASA Technical Reports Server (NTRS)

Long, Anne; Kelbel, David; Lee, Taesul; Leung, Dominic; Carpenter, Russell; Gramling, Cheryl; Bauer, Frank (Technical Monitor)

2002-01-01

The Guidance, Navigation, and Control Center (GNCC) at Goddard Space Flight Center (GSFC) has successfully developed high-accuracy autonomous satellite navigation systems using the National Aeronautics and Space Administration's (NASA's) space and ground communications systems and the Global Positioning System (GPS). In addition, an autonomous navigation system that uses celestial object sensor measurements is currently under development and has been successfully tested using real Sun and Earth horizon measurements.The GNCC has developed advanced spacecraft systems that provide autonomous navigation and control of formation flyers in near-Earth, high-Earth, and libration point orbits. To support this effort, the GNCC is assessing the relative navigation accuracy achievable for proposed formations using GPS, intersatellite crosslink, ground-to-satellite Doppler, and celestial object sensor measurements. This paper evaluates the performance of these relative navigation approaches for three proposed missions with two or more vehicles maintaining relatively tight formations. High-fidelity simulations were performed to quantify the absolute and relative navigation accuracy as a function of navigation algorithm and measurement type. Realistically-simulated measurements were processed using the extended Kalman filter implemented in the GPS Enhanced Inboard Navigation System (GEONS) flight software developed by GSFC GNCC. Solutions obtained by simultaneously estimating all satellites in the formation were compared with the results obtained using a simpler approach based on differencing independently estimated state vectors.

Evaluation of optical data for Mars approach navigation.

NASA Technical Reports Server (NTRS)

Jerath, N.

1972-01-01

Investigation of several optical data types which can be obtained from science and engineering instruments normally aboard interplanetary spacecraft. TV cameras are assumed to view planets or satellites and stars for celestial references. Also, spacecraft attitude sensors are assumed to yield celestial references. The investigation of approach phases of typical Mars missions showed that the navigation accuracy was greatly enhanced with the addition of optical data to radio data. Viewing stars and the planet Mars was found most advantageous ten days before Mars encounter, and viewing Deimos or Phobos and stars was most advantageous within ten days of encounter.

Accuracy of sun localization in the second step of sky-polarimetric Viking navigation for north determination: a planetarium experiment.

PubMed

Farkas, Alexandra; Száz, Dénes; Egri, Ádám; Blahó, Miklós; Barta, András; Nehéz, Dóra; Bernáth, Balázs; Horváth, Gábor

2014-07-01

It is a widely discussed hypothesis that Viking seafarers might have been able to locate the position of the occluded sun by means of dichroic or birefringent crystals, the mysterious sunstones, with which they could analyze skylight polarization. Although the atmospheric optical prerequisites and certain aspects of the efficiency of this sky-polarimetric Viking navigation have been investigated, the accuracy of the main steps of this method has not been quantitatively examined. To fill in this gap, we present here the results of a planetarium experiment in which we measured the azimuth and elevation errors of localization of the invisible sun. In the planetarium sun localization was performed in two selected celestial points on the basis of the alignments of two small sections of two celestial great circles passing through the sun. In the second step of sky-polarimetric Viking navigation the navigator needed to determine the intersection of two such celestial circles. We found that the position of the sun (solar elevation θ(S), solar azimuth φ(S)) was estimated with an average error of +0.6°≤Δθ≤+8.8° and -3.9°≤Δφ≤+2.0°. We also calculated the compass direction error when the estimated sun position is used for orienting with a Viking sun-compass. The northern direction (ω(North)) was determined with an error of -3.34°≤Δω(North)≤+6.29°. The inaccuracy of the second step of this navigation method was high (Δω(North)=-16.3°) when the solar elevation was 5°≤θ(S)≤25°, and the two selected celestial points were far from the sun (at angular distances 95°≤γ(1), γ(2)≤115°) and each other (125°≤δ≤145°). Considering only this second step, the sky-polarimetric navigation could be more accurate in the mid-summer period (June and July), when in the daytime the sun is high above the horizon for long periods. In the spring (and autumn) equinoctial period, alternative methods (using a twilight board, for example) might be more appropriate. Since Viking navigators surely also committed further errors in the first and third steps, the orientation errors presented here underestimate the net error of the whole sky-polarimetric navigation.

Relative optical navigation around small bodies via Extreme Learning Machine

NASA Astrophysics Data System (ADS)

Law, Andrew M.

To perform close proximity operations under a low-gravity environment, relative and absolute positions are vital information to the maneuver. Hence navigation is inseparably integrated in space travel. Extreme Learning Machine (ELM) is presented as an optical navigation method around small celestial bodies. Optical Navigation uses visual observation instruments such as a camera to acquire useful data and determine spacecraft position. The required input data for operation is merely a single image strip and a nadir image. ELM is a machine learning Single Layer feed-Forward Network (SLFN), a type of neural network (NN). The algorithm is developed on the predicate that input weights and biases can be randomly assigned and does not require back-propagation. The learned model is the output layer weights which are used to calculate a prediction. Together, Extreme Learning Machine Optical Navigation (ELM OpNav) utilizes optical images and ELM algorithm to train the machine to navigate around a target body. In this thesis the asteroid, Vesta, is the designated celestial body. The trained ELMs estimate the position of the spacecraft during operation with a single data set. The results show the approach is promising and potentially suitable for on-board navigation.

Reclaiming Celestial Navigation Using a Contemporary Hawaiian Worldview of the Heavens

NASA Astrophysics Data System (ADS)

Dye, Ahia G.; Ha`o, Celeste; Slater, Timothy F.; Slater, Stephanie J.

2015-08-01

The immense challenges of successfully navigating the vast Pacific basin without modern instruments are well-known. At the same time, the precise methods used by ancient Polynesian wayfinders are largely undocumented, the strategies being wholly unfamiliar to early European navigators from higher latitudes with formal training in charts and tables. Leading the wave of a Hawaiian-Renaissance, contemporary Hawaiian seafarers are boldly reclaiming their heritage by recreating and sailing double hulled canoes by instrument-free, navigation techniques. Many of these navigational techniques are probably reminiscent of earlier strategies, and are proving to be highly successful. The result is that numerous canoes are now making repeated trips throughout the Polynesian Triangle, and reaching beyond to soon circumnavigate the globe. Not surprisingly, a vital component of any navigational system far from terrestrial landmarks is based on the changing positions and predictable motions of the Sun and stars. Although many of the indigenous star names are lost to history, some of the most important star names for celestial navigation have been painstakingly re-claimed. Other critically important navigational stars are being named by the respected Hawaiian Guild Navigators and their teams of educators who are conducting navigation training for Hawaiian sailing crews. The authors are collecting and documenting these new star names along-with their identifiable asterisms-in the service of educating both the public and the next generation of navigators.

Celestial Navigation for High School Students.

ERIC Educational Resources Information Center

Bell, Carroll Wilson

Reported is a study of a syllabus designed to teach students how to determine a position by celestial means. The syllabus was intended to augment existing curricula and be a topic for special interest groups and not designed as a semester-long course in itself. Each of the 14 lessons included was preceded by specific objectives written in…

Two odometers in honeybees?

PubMed

Dacke, M; Srinivasan, M V

2008-10-01

Although several studies have examined how honeybees gauge and report the distance and direction of a food source to their nestmates, relatively little is known about how this information is combined to obtain a representation of the position of the food source. In this study we manipulate the amount of celestial compass information available to the bee during flight, and analyse the encoding of spatial information in the waggle dance as well as in the navigation of the foraging bee. We find that the waggle dance encodes information about the total distance flown to the food source, even when celestial compass cues are available only for a part of the journey. This stands in contrast to how a bee gauges distance flown when it navigates back to a food source that it already knows. When bees were trained to find a feeder placed at a fixed distance in a tunnel in which celestial cues were partially occluded and then tested in a tunnel that was fully open to the sky, they searched for the feeder at a distance that corresponds closely to the distance that was flown under the open sky during the training. Thus, when navigating back to a food source, information about distance travelled is disregarded when there is no concurrent input from the celestial compass. We suggest that bees may possess two different odometers - a 'community' odometer that is used to provide information to nestmates via the dance, and a 'personal' odometer that is used by an experienced individual to return to a previously visited source.

"Bridging the Gap" through Australian Cultural Astronomy

NASA Astrophysics Data System (ADS)

Hamacher, Duane W.; Norris, Ray P.

2011-01-01

For more than 50,000 years, Indigenous Australians have incorporated celestial events into their oral traditions and used the motions of celestial bodies for navigation, time-keeping, food economics, and social structure. In this paper, we explore the ways in which Aboriginal people made careful observations of the sky, measurements of celestial bodies, and incorporated astronomical events into complex oral traditions by searching for written records of time-keeping using celestial bodies, the use of rising and setting stars as indicators of special events, recorded observations of variable stars, the solar cycle, and lunar phases (including ocean tides and eclipses) in oral tradition, as well as astronomical measurements of the equinox, solstice, and cardinal points.

Celestial Navigation with the Stereographic Projection

ERIC Educational Resources Information Center

Hutton, D. R.

1977-01-01

Presented is an exercise in the ability to navigate by the stars. It applies difficult concepts of positional astronomy concerning coordinate systems and time. Stereographic projection is utilized because it allows rapid completion of calculations and measurements and keeps the concepts clear to the students. (MA)

Autonomous celestial navigation based on Earth ultraviolet radiance and fast gradient statistic feature extraction

NASA Astrophysics Data System (ADS)

Lu, Shan; Zhang, Hanmo

2016-01-01

To meet the requirement of autonomous orbit determination, this paper proposes a fast curve fitting method based on earth ultraviolet features to obtain accurate earth vector direction, in order to achieve the high precision autonomous navigation. Firstly, combining the stable characters of earth ultraviolet radiance and the use of transmission model software of atmospheric radiation, the paper simulates earth ultraviolet radiation model on different time and chooses the proper observation band. Then the fast improved edge extracting method combined Sobel operator and local binary pattern (LBP) is utilized, which can both eliminate noises efficiently and extract earth ultraviolet limb features accurately. And earth's centroid locations on simulated images are estimated via the least square fitting method using part of the limb edges. Taken advantage of the estimated earth vector direction and earth distance, Extended Kalman Filter (EKF) is applied to realize the autonomous navigation finally. Experiment results indicate the proposed method can achieve a sub-pixel earth centroid location estimation and extremely enhance autonomous celestial navigation precision.

Visual navigation in desert ants Cataglyphis fortis: are snapshots coupled to a celestial system of reference?

PubMed

Akesson, Susanne; Wehner, Rüdiger

2002-07-01

Central-place foraging insects such as desert ants of the genus Cataglyphis use both path integration and landmarks to navigate during foraging excursions. The use of landmark information and a celestial system of reference for nest location was investigated by training desert ants returning from an artificial feeder to find the nest at one of four alternative positions located asymmetrically inside a four-cylinder landmark array. The cylindrical landmarks were all of the same size and arranged in a square, with the nest located in the southeast corner. When released from the compass direction experienced during training (southeast), the ants searched most intensely at the fictive nest position. When instead released from any of the three alternative directions of approach (southwest, northwest or northeast), the same individuals instead searched at two of the four alternative positions by initiating their search at the position closest to the direction of approach when entering the landmark square and then returning to the position at which snapshot, current landmark image and celestial reference information were in register. The results show that, in the ants' visual snapshot memory, a memorized landmark scene can temporarily be decoupled from a memorized celestial system of reference.

A Ka-Band Celestial Reference Frame with Applications to Deep Space Navigation

NASA Technical Reports Server (NTRS)

Jacobs, Christopher S.; Clark, J. Eric; Garcia-Miro, Cristina; Horiuchi, Shinji; Sotuela, Ioana

2011-01-01

The Ka-band radio spectrum is now being used for a wide variety of applications. This paper highlights the use of Ka-band as a frequency for precise deep space navigation based on a set of reference beacons provided by extragalactic quasars which emit broadband noise at Ka-band. This quasar-based celestial reference frame is constructed using X/Ka-band (8.4/32 GHz) from fifty-five 24-hour sessions with the Deep Space Network antennas in California, Australia, and Spain. We report on observations which have detected 464 sources covering the full 24 hours of Right Ascension and declinations down to -45 deg. Comparison of this X/Ka-band frame to the international standard S/X-band (2.3/8.4 GHz) ICRF2 shows wRMS agreement of approximately 200 micro-arcsec in alpha cos(delta) and approximately 300 micro-arcsec in delta. There is evidence for systematic errors at the 100 micro-arcsec level. Known errors include limited SNR, lack of instrumental phase calibration, tropospheric refraction mis-modeling, and limited southern geometry. The motivation for extending the celestial reference frame to frequencies above 8 GHz is to access more compact source morphology for improved frame stability and to support spacecraft navigation for Ka-band based NASA missions.

Spatial water maze learning using celestial cues by the meadow vole, Microtus pennsylvanicus.

PubMed

Kavaliers, M; Galea, L A

1994-03-31

The Morris water maze is widely used to evaluate to evaluate the spatial learning ability of rodents under laboratory settings. The present study demonstrates that reproductive male meadow voles, Microtus pennsylvanicus, are able to acquire and retain a spatial water maze task using celestial cues. Voles were able to acquire a modified outdoor Morris water maze task over 4 trials per day, whereby they had to learn and remember the location of a submerged hidden platform, using the position of the sun and associated celestial cues. Their proficiency on this task was related to the availability of the celestial cues, with voles displaying significantly poorer spatial navigation on overcast than clear days and when the testing time (and position of the sun and associated celestial cues) was shifted from morning to afternoon. These findings with meadow voles support the ecological relevance of the water maze task.

Visual Navigation in Nocturnal Insects.

PubMed

Warrant, Eric; Dacke, Marie

2016-05-01

Despite their tiny eyes and brains, nocturnal insects have evolved a remarkable capacity to visually navigate at night. Whereas some use moonlight or the stars as celestial compass cues to maintain a straight-line course, others use visual landmarks to navigate to and from their nest. These impressive abilities rely on highly sensitive compound eyes and specialized visual processing strategies in the brain. ©2016 Int. Union Physiol. Sci./Am. Physiol. Soc.

Kilohoku Ho`okele Wa`a : Astronomy of the Hawaiian Navigators

NASA Astrophysics Data System (ADS)

Slater, Stephanie; Slater, Timothy F.; Baybayan, Kalepa C.

2016-01-01

This poster provides an introduction to the astronomy of the Hawaiian wayfinders, Kilohoku Ho`okele Wa`a. Rooted in a legacy of navigation across the Polynesian triangle, wayfinding astronomy has been part of a suite of skills that allows navigators to deliberately hop between the small islands of the Pacific, for thousands of years. Forty years ago, in one manifestation of the Hawaiian Renaissance, our teachers demonstrated that ancient Hawaiians were capable of traversing the wide Pacific to settle and trade on islands separated by thousands of miles. Today those same mentors train a new generation of navigators, making Hawaiian voyaging a living, evolving, sustainable endeavor. This poster presents two components of astronomical knowledge that all crewmen, but particularly those in training to become navigators, learn early in their training. Na Ohana Hoku, the Hawaiian Star Families constitute the basic units of the Hawaiian sky. In contrast to the Western system of 88 constellations, Na Ohana Hoku divides the sky into four sections that each run from the northern to the southern poles. This configuration reduces cognitive load, allowing the navigator to preserve working memory for other complex tasks. In addition, these configurations of stars support the navigator in finding and generatively using hundreds of individual, and navigationally important pairs of stars. The Hawaiian Star Compass divides the celestial sphere into a directional system that uses 32 rather than 8 cardinal points. Within the tropics, the rising and setting of celestial objects are consistent within the Hawaiian Star Compass, providing for extremely reliable direction finding. Together, Na Ohana Hoku and the Hawaiian Star Compass provide the tropical navigator with astronomical assistance that is not available to, and would have been unknown to Western navigators trained at higher latitudes.

A School Looks to the Sea.

ERIC Educational Resources Information Center

Eastman, Charles, Jr.

1980-01-01

Describes an educational program at a secondary school in Massachusetts in which students explore whaling, celestial and terrestrial navigation, marine biology, commercial fishing methods, and the ecology of marine nurseries. (DB)

A Snapshot-Based Mechanism for Celestial Orientation.

PubMed

El Jundi, Basil; Foster, James J; Khaldy, Lana; Byrne, Marcus J; Dacke, Marie; Baird, Emily

2016-06-06

In order to protect their food from competitors, ball-rolling dung beetles detach a piece of dung from a pile, shape it into a ball, and roll it away along a straight path [1]. They appear to rely exclusively on celestial compass cues to maintain their bearing [2-8], but the mechanism that enables them to use these cues for orientation remains unknown. Here, we describe the orientation strategy that allows dung beetles to use celestial cues in a dynamic fashion. We tested the underlying orientation mechanism by presenting beetles with a combination of simulated celestial cues (sun, polarized light, and spectral cues). We show that these animals do not rely on an innate prediction of the natural geographical relationship between celestial cues, as other navigating insects seem to [9, 10]. Instead, they appear to form an internal representation of the prevailing celestial scene, a "celestial snapshot," even if that scene represents a physical impossibility for the real sky. We also find that the beetles are able to maintain their bearing with respect to the presented cues only if the cues are visible when the snapshot is taken. This happens during the "dance," a behavior in which the beetle climbs on top of its ball and rotates about its vertical axis [11]. This strategy for reading celestial signals is a simple but efficient mechanism for straight-line orientation. Copyright © 2016 Elsevier Ltd. All rights reserved.

A SINS/SRS/GNS Autonomous Integrated Navigation System Based on Spectral Redshift Velocity Measurements.

PubMed

Wei, Wenhui; Gao, Zhaohui; Gao, Shesheng; Jia, Ke

2018-04-09

In order to meet the requirements of autonomy and reliability for the navigation system, combined with the method of measuring speed by using the spectral redshift information of the natural celestial bodies, a new scheme, consisting of Strapdown Inertial Navigation System (SINS)/Spectral Redshift (SRS)/Geomagnetic Navigation System (GNS), is designed for autonomous integrated navigation systems. The principle of this SINS/SRS/GNS autonomous integrated navigation system is explored, and the corresponding mathematical model is established. Furthermore, a robust adaptive central difference particle filtering algorithm is proposed for this autonomous integrated navigation system. The simulation experiments are conducted and the results show that the designed SINS/SRS/GNS autonomous integrated navigation system possesses good autonomy, strong robustness and high reliability, thus providing a new solution for autonomous navigation technology.

Kilohoku Ho`okele Wa`a : Astronomy of the Modern Hawaiian Wayfinders

NASA Astrophysics Data System (ADS)

Ha`o, Celeste; Dye, Ahia G.; Slater, Stephanie J.; Slater, Timothy F.; Baybayan, Kalepa

2015-08-01

This paper provides an introduction to Kilohoku Ho`okele Wa`a, the astronomy of the Hawaiian wayfinders. Rooted in a legacy of navigation across the Polynesian triangle, wayfinding astronomy has been part of a suite of skills that allows navigators to deliberately hop between the small islands of the Pacific, for thousands of years. Forty years ago, in one manifestation of the Hawaiian Renaissance, our teachers demonstrated that ancient Hawaiians were capable of traversing the wide Pacific to settle and trade on islands separated by thousands of miles. Today those same mentors train a new generation of navigators, making Hawaiian voyaging a living, evolving, sustainable endeavor. This paper presents two components of astronomical knowledge that all crewmen, but particularly those in training to become navigators, learn early in their training. Na Ohana Hoku, the Hawaiian Star Families constitute the basic units of the Hawaiian sky. In contrast to the Western system of 88 constellations, Na Ohana Hoku divides the sky into four sections that each run from the northern to the southern poles. This configuration reduces cognitive load, allowing the navigator to preserve working memory for other complex tasks. In addition, these configurations of stars support the navigator in finding and generatively using hundreds of individual, and navigationally important pairs of stars. The Hawaiian Star Compass divides the celestial sphere into a directional system that uses 32 rather than 8 cardinal points. Within the tropics, the rising and setting of celestial objects are consistent within the Hawaiian Star Compass, providing for extremely reliable direction finding. Together, Na Ohana Hoku and the Hawaiian Star Compass provide the tropical navigator with astronomical assistance that is not available to, and would have been unknown to Western navigators trained at higher latitudes.

How well does the Rayleigh model describe the E-vector distribution of skylight in clear and cloudy conditions? A full-sky polarimetric study.

PubMed

Suhai, Bence; Horváth, Gábor

2004-09-01

We present the first high-resolution maps of Rayleigh behavior in clear and cloudy sky conditions measured by full-sky imaging polarimetry at the wavelengths of 650 nm (red), 550 nm (green), and 450 nm (blue) versus the solar elevation angle thetas. Our maps display those celestial areas at which the deviation deltaalpha = /alphameas - alphaRyleigh/ is below the threshold alphathres = 5 degrees, where alphameas is the angle of polarization of skylight measured by full-sky imaging polarimetry, and alphaRayleigh is the celestial angle of polarization calculated on the basis of the single-scattering Rayleigh model. From these maps we derived the proportion r of the full sky for which the single-scattering Rayleigh model describes well (with an accuracy of deltaalpha = 5 degrees) the E-vector alignment of skylight. Depending on thetas, r is high for clear skies, especially for low solar elevations (40% < r < 70% for thetas < or = 13 degrees). Depending on the cloud cover and the solar illumination, r decreases more or less under cloudy conditions, but sometimes its value remains remarkably high, especially at low solar elevations (rmax = 69% for thetas = 0 degrees). The proportion r of the sky that follows the Rayleigh model is usually higher for shorter wavelengths under clear as well as cloudy sky conditions. This partly explains why the shorter wavelengths are generally preferred by animals navigating by means of the celestial polarization. We found that the celestial E-vector pattern generally follows the Rayleigh pattern well, which is a fundamental hypothesis in the studies of animal orientation and human navigation (e.g., in aircraft flying near the geomagnetic poles and using a polarization sky compass) with the use of the celestial alpha pattern.

46 CFR 11.903 - Officer endorsements requiring examinations.

Code of Federal Regulations, 2014 CFR

2014-10-01

... self-propelled vessels of less than 200 GRT would, however, require an examination in celestial navigation. (4) Second mate of oceans or near-coastal vessels when upgrading from third mate of oceans or...

Harbour seals (Phoca vitulina) can steer by the stars.

PubMed

Mauck, Björn; Gläser, Nele; Schlosser, Wolfhard; Dehnhardt, Guido

2008-10-01

Offshore orientation in marine mammals is still a mystery. For visual orientation during night-time foraging and travelling in the open seas, seals cannot rely on distant terrestrial landmarks, and thus might use celestial cues as repeatedly shown for nocturnally migrating birds. Although seals detect enough stars to probably allow for astronavigation, it was unclear whether they can orient by the night sky. The widely accepted cognitive mechanism for bird night-time orientation by celestial cues is a time-independent star compass with learned geometrical star configurations used to pinpoint north as the rotational centre of the starry sky while there is no conclusive evidence for a time-compensated star compass or true star navigation. Here, we present results for two harbour seals orienting in a custom made swimming planetarium. Both seals learned to highly accurately identify a lodestar out of a pseudo-randomly oriented, realistic projection of the northern hemisphere night sky. Providing the first evidence for star orientation capability in a marine mammal, our seals' outstanding directional precision would allow them to steer by following lodestars of learned star courses, a celestial orientation mechanism that has been known to be used by Polynesian navigators but has not been considered for animals yet.

Kilohoku - Ho‘okele Wa‘a: Hawaiian Navigational Astronomy

NASA Astrophysics Data System (ADS)

Dye, Ahia; Ha'o, Celeste; Slater, Timothy F.; Slater, Stephanie

2015-01-01

Over thousands of years of Pacific Basin settlement, Polynesians developed a complex, scientific understanding of the cosmos, including a generative view of the celestial sphere. Memorizing the location and spatial relationships of hundreds of stars, across changing latitudes, this astronomy was one of the four scientific knowledge bases Polynesians used to navigate thousands of miles, across open water, without instrumentation. After Western colonization, this large body of knowledge was nearly lost to Hawaiians. Since the Hawaiian Renaissance, much of this knowledge has been reconstructed, and is again in use in open oceanic navigation. While some of this knowledge has been shared with the broader public, much of what we know has been unavailable to those beyond the family of navigators. This paper represents an attempt to begin sharing this catalog of knowledge with the outside world, with the hopes that the larger community will appreciate the complexity of astronomical knowledge possessed by navigators, and that the international body of astronomy historians will help insure that this knowledge will not be lost again. This paper will present, Na ´Ohanahōkū, the Hawaiian star families that divide the celestial sphere into four wedges, running from the circumpolar north, beyond the horizon to the south. Na Hoku Huihui, or Hawaiian constellations will be discussed, in addition to a brief introduction to the setting and rising pairs that are used to determine direction and latitude.

A SINS/SRS/GNS Autonomous Integrated Navigation System Based on Spectral Redshift Velocity Measurements

PubMed Central

Wei, Wenhui; Gao, Zhaohui; Gao, Shesheng; Jia, Ke

2018-01-01

In order to meet the requirements of autonomy and reliability for the navigation system, combined with the method of measuring speed by using the spectral redshift information of the natural celestial bodies, a new scheme, consisting of Strapdown Inertial Navigation System (SINS)/Spectral Redshift (SRS)/Geomagnetic Navigation System (GNS), is designed for autonomous integrated navigation systems. The principle of this SINS/SRS/GNS autonomous integrated navigation system is explored, and the corresponding mathematical model is established. Furthermore, a robust adaptive central difference particle filtering algorithm is proposed for this autonomous integrated navigation system. The simulation experiments are conducted and the results show that the designed SINS/SRS/GNS autonomous integrated navigation system possesses good autonomy, strong robustness and high reliability, thus providing a new solution for autonomous navigation technology. PMID:29642549

Smoothing and Predicting Celestial Pole Offsets using a Kalman Filter and Smoother

NASA Astrophysics Data System (ADS)

Nastula, J.; Chin, T. M.; Gross, R. S.; Winska, M.; Winska, J.

2017-12-01

Since the early days of interplanetary spaceflight, accounting for changes in the Earth's rotation is recognized to be critical for accurate navigation. In the 1960s, tracking anomalies during the Ranger VII and VIII lunar missions were traced to errors in the Earth orientation parameters. As a result, Earth orientation calibration methods were improved to support the Mariner IV and V planetary missions. Today, accurate Earth orientation parameters are used to track and navigate every interplanetary spaceflight mission. The interplanetary spacecraft tracking and navigation teams at JPL require the UT1 and polar motion parameters, and these Earth orientation parameters are estimated by the use of a Kalman filter to combine past measurements of these parameters and predict their future evolution. A model was then used to provide the nutation/precession components of the Earth's orientation separately. As a result, variations caused by the free core nutation were not taken into account. But for the highest accuracy, these variations must be considered. So JPL recently developed an approach based upon the use of a Kalman filter and smoother to provide smoothed and predicted celestial pole offsets (CPOs) to the interplanetary spacecraft tracking and navigation teams. The approach used at JPL to do this and an evaluation of the accuracy of the predicted CPOs will be given here.

The significance of direct sunlight and polarized skylight in the ant's celestial system of navigation.

PubMed

Wehner, Rüdiger; Müller, Martin

2006-08-15

As textbook knowledge has it, bees and ants use polarized skylight as a backup cue whenever the main compass cue, the sun, is obscured by clouds. Here we show, by employing a unique experimental paradigm, that the celestial compass system of desert ants, Cataglyphis, relies predominantly on polarized skylight. If ants experience only parts of the polarization pattern during training but the full pattern in a subsequent test situation, they systematically deviate from their true homeward courses, with the systematics depending on what parts of the skylight patterns have been presented during training. This "signature" of the polarization compass remains unaltered, even if the ants can simultaneously experience the sun, which, if presented alone, enables the ants to select their true homeward courses. Information provided by direct sunlight and polarized skylight is picked up by different parts of the ant's compound eyes and is channeled into two rather separate systems of navigation.

Animal navigation: a galaxy of cues.

PubMed

Gould, James L

2013-02-18

Elegant new experiments show that on clear nights and in the absence of other celestial cues, dung beetles can orient their routes to the band of stars known as the Milky Way. Copyright © 2013 Elsevier Ltd. All rights reserved.

Optimal scheme of star observation of missile-borne inertial navigation system/stellar refraction integrated navigation

NASA Astrophysics Data System (ADS)

Lu, Jiazhen; Yang, Lie

2018-05-01

To achieve accurate and completely autonomous navigation for spacecraft, inertial/celestial integrated navigation gets increasing attention. In this study, a missile-borne inertial/stellar refraction integrated navigation scheme is proposed. Position Dilution of Precision (PDOP) for stellar refraction is introduced and the corresponding equation is derived. Based on the condition when PDOP reaches the minimum value, an optimized observation scheme is proposed. To verify the feasibility of the proposed scheme, numerical simulation is conducted. The results of the Extended Kalman Filter (EKF) and Unscented Kalman Filter (UKF) are compared and impact factors of navigation accuracy are studied in the simulation. The simulation results indicated that the proposed observation scheme has an accurate positioning performance, and the results of EKF and UKF are similar.

Optimal scheme of star observation of missile-borne inertial navigation system/stellar refraction integrated navigation.

PubMed

Lu, Jiazhen; Yang, Lie

2018-05-01

To achieve accurate and completely autonomous navigation for spacecraft, inertial/celestial integrated navigation gets increasing attention. In this study, a missile-borne inertial/stellar refraction integrated navigation scheme is proposed. Position Dilution of Precision (PDOP) for stellar refraction is introduced and the corresponding equation is derived. Based on the condition when PDOP reaches the minimum value, an optimized observation scheme is proposed. To verify the feasibility of the proposed scheme, numerical simulation is conducted. The results of the Extended Kalman Filter (EKF) and Unscented Kalman Filter (UKF) are compared and impact factors of navigation accuracy are studied in the simulation. The simulation results indicated that the proposed observation scheme has an accurate positioning performance, and the results of EKF and UKF are similar.

JPL VLBI Analysis Center IVS Annual Report for 2004

NASA Technical Reports Server (NTRS)

Jacobs, Chris

2005-01-01

This report describes the activities of the JPL VLBI analysis center for the year 2004. We continue to be celestial reference frame, terrestrial reference frame, earth orientation, and spacecraft navigation work using the VLBI technique. There are several areas of our work that are undergoing active development. In 2004 we demonstrated 1 mm level troposphere calibration on an intercontinental baseline. We detected our first X/Ka (8.4/32 GHz) VLBI fringes. We began to deploy Mark 5 recorders and to interface the Mark 5 units to our software correlator. We also have actively participated in the international VLBI community through our involvement in six papers at the February IVS meeting and by collaborating on a number of projects such as densifying the S/X celestial frame creating celestial frames at K (24 GHz) and Q-bands ($# GHz)>

The bee's map of the e-vector pattern in the sky.

PubMed

Rossel, S; Wehner, R

1982-07-01

It has long been known that bees can use the pattern of polarized light in the sky as a compass cue even if they can see only a small part of the whole pattern. How they solve this problem has remained enigmatic. Here we show that the bees rely on a generalized celestial map that is used invariably throughout the day. We reconstruct this map by analyzing the navigation errors made by bees to which single e-vectors are displayed. In addition, we demonstrate how the bee's celestial map can be derived from the e-vector patterns in the sky.

On-Board Perception System For Planetary Aerobot Balloon Navigation

NASA Technical Reports Server (NTRS)

Balaram, J.; Scheid, Robert E.; T. Salomon, Phil

1996-01-01

NASA's Jet Propulsion Laboratory is implementing the Planetary Aerobot Testbed to develop the technology needed to operate a robotic balloon aero-vehicle (Aerobot). This earth-based system would be the precursor for aerobots designed to explore Venus, Mars, Titan and other gaseous planetary bodies. The on-board perception system allows the aerobot to localize itself and navigate on a planet using information derived from a variety of celestial, inertial, ground-imaging, ranging, and radiometric sensors.

The AFJROTC Program at Hopewell High School

ERIC Educational Resources Information Center

Schultes, Charles R., Jr.

1975-01-01

Describes the textbooks, the curricular, and co-curricular activities in the AFJROTC program at Hopewell High School. Includes a description of a specialized, fourth-year course extension which includes celestial navigation, communicative techniques, computer systems, meteorology, and Air Force Role in National Defense. (MLH)

VisiOmatic: Celestial image viewer

NASA Astrophysics Data System (ADS)

Bertin, Emmanuel; Marmo, Chiara; Pillay, Ruven

2014-08-01

VisiOmatic is a web client for IIPImage (ascl:1408.009) and is used to visualize and navigate through large science images from remote locations. It requires STIFF (ascl:1110.006), is based on the Leaflet Javascript library, and works on both touch-based and mouse-based devices.

The significance of direct sunlight and polarized skylight in the ant’s celestial system of navigation

PubMed Central

Wehner, Rüdiger; Müller, Martin

2006-01-01

As textbook knowledge has it, bees and ants use polarized skylight as a backup cue whenever the main compass cue, the sun, is obscured by clouds. Here we show, by employing a unique experimental paradigm, that the celestial compass system of desert ants, Cataglyphis, relies predominantly on polarized skylight. If ants experience only parts of the polarization pattern during training but the full pattern in a subsequent test situation, they systematically deviate from their true homeward courses, with the systematics depending on what parts of the skylight patterns have been presented during training. This “signature” of the polarization compass remains unaltered, even if the ants can simultaneously experience the sun, which, if presented alone, enables the ants to select their true homeward courses. Information provided by direct sunlight and polarized skylight is picked up by different parts of the ant’s compound eyes and is channeled into two rather separate systems of navigation. PMID:16888039

The consistency of the current conventional celestial and terrestrial reference frames and the conventional EOP series

NASA Astrophysics Data System (ADS)

Heinkelmann, R.; Belda-Palazon, S.; Ferrándiz, J.; Schuh, H.

2015-08-01

For applications in Earth sciences, navigation, and astronomy the celestial (ICRF) and terrestrial (ITRF) reference frames as well as the orientation among them, the Earth orientation parameters (EOP), have to be consistent at the level of 1 mm and 0.1 mm/yr (GGOS recommendations). We assess the effect of unmodelled geophysical signals in the regularized coordinates and the sensitivity with respect to different a priori EOP and celestial reference frames. The EOP are determined using the same VLBI data but with station coordinates fixed on different TRFs. The conclusion is that within the time span of data incorporated into ITRF2008 (Altamimi, et al., 2011) the ITRF2008 and the IERS 08 C04 are consistent. This consistency involves that non-linear station motion such as unmodelled geophysical signals partly affect the IERS 08 C04 EOP. There are small but not negligible inconsistencies between the conventional celestial reference frame, ICRF2 (Fey, et al., 2009), the ITRF2008 and the conventional EOP that are quantified by comparing VTRF2008 (Böckmann, et al., 2010) and ITRF2008.

Insect Responses to Linearly Polarized Reflections: Orphan Behaviors Without Neural Circuits.

PubMed

Heinloth, Tanja; Uhlhorn, Juliane; Wernet, Mathias F

2018-01-01

The e-vector orientation of linearly polarized light represents an important visual stimulus for many insects. Especially the detection of polarized skylight by many navigating insect species is known to improve their orientation skills. While great progress has been made towards describing both the anatomy and function of neural circuit elements mediating behaviors related to navigation, relatively little is known about how insects perceive non-celestial polarized light stimuli, like reflections off water, leaves, or shiny body surfaces. Work on different species suggests that these behaviors are not mediated by the "Dorsal Rim Area" (DRA), a specialized region in the dorsal periphery of the adult compound eye, where ommatidia contain highly polarization-sensitive photoreceptor cells whose receptive fields point towards the sky. So far, only few cases of polarization-sensitive photoreceptors have been described in the ventral periphery of the insect retina. Furthermore, both the structure and function of those neural circuits connecting to these photoreceptor inputs remain largely uncharacterized. Here we review the known data on non-celestial polarization vision from different insect species (dragonflies, butterflies, beetles, bugs and flies) and present three well-characterized examples for functionally specialized non-DRA detectors from different insects that seem perfectly suited for mediating such behaviors. Finally, using recent advances from circuit dissection in Drosophila melanogaster , we discuss what types of potential candidate neurons could be involved in forming the underlying neural circuitry mediating non-celestial polarization vision.

Archaic artifacts resembling celestial spheres

NASA Astrophysics Data System (ADS)

Dimitrakoudis, S.; Papaspyrou, P.; Petoussis, V.; Moussas, X.

We present several bronze artifacts from the Archaic Age in Greece (750-480 BC) that resemble celestial spheres or forms of other astronomical significance. They are studied in the context of the Dark Age transition from Mycenaean Age astronomical themes to the philosophical and practical revival of astronomy in the Classical Age with its plethora of astronomical devices. These artifacts, mostly votive in nature are spherical in shape and appear in a variety of forms their most striking characteristic being the depiction of meridians and/or an equator. Most of those artifacts come from Thessaly, and more specifically from the temple of Itonia Athena at Philia, a religious center of pan-Hellenic significance. Celestial spheres, similar in form to the small artifacts presented in this study, could be used to measure latitudes, or estimate the time at a known place, and were thus very useful in navigation.

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.

Beacons for supporting lunar landing navigation

NASA Astrophysics Data System (ADS)

Theil, Stephan; Bora, Leonardo

2017-03-01

Current and future planetary exploration missions involve a landing on the target celestial body. Almost all of these landing missions are currently relying on a combination of inertial and optical sensor measurements to determine the current flight state with respect to the target body and the desired landing site. As soon as an infrastructure at the landing site exists, the requirements as well as conditions change for vehicles landing close to this existing infrastructure. This paper investigates the options for ground-based infrastructure supporting the onboard navigation system and analyzes the impact on the achievable navigation accuracy. For that purpose, the paper starts with an existing navigation architecture based on optical navigation and extends it with measurements to support navigation with ground infrastructure. A scenario of lunar landing is simulated and the provided functions of the ground infrastructure as well as the location with respect to the landing site are evaluated. The results are analyzed and discussed.

Analysis of a novel device-level SINS/ACFSS deeply integrated navigation method

NASA Astrophysics Data System (ADS)

Zhang, Hao; Qin, Shiqiao; Wang, Xingshu; Jiang, Guangwen; Tan, Wenfeng; Wu, Wei

2017-02-01

The combination of the strap-down inertial navigation system(SINS) and the celestial navigation system(CNS) is one of the popular measures to constitute the integrated navigation system. A star sensor(SS) is used as a precise attitude determination device in CNS. To solve the problem that the star image obtained by SS is motion-blurred under dynamic conditions, the attitude-correlated frames(ACF) approach is presented and the star sensor which works based on ACF approach is named ACFSS. Depending on the ACF approach, a novel device-level SINS/ACFSS deeply integrated navigation method is proposed in this paper. Feedback to the ACF process from the error of the gyro is one of the typical characters of the SINS/CNS deeply integrated navigation method. Herein, simulation results have verified its validity and efficiency in improving the accuracy of gyro and it can be proved that this method is feasible.

The sensory ecology of ocean navigation.

PubMed

Lohmann, Kenneth J; Lohmann, Catherine M F; Endres, Courtney S

2008-06-01

How animals guide themselves across vast expanses of open ocean, sometimes to specific geographic areas, has remained an enduring mystery of behavioral biology. In this review we briefly contrast underwater oceanic navigation with terrestrial navigation and summarize the advantages and constraints of different approaches used to analyze animal navigation in the sea. In addition, we highlight studies and techniques that have begun to unravel the sensory cues that underlie navigation in sea turtles, salmon and other ocean migrants. Environmental signals of importance include geomagnetic, chemical and hydrodynamic cues, perhaps supplemented in some cases by celestial cues or other sources of information that remain to be discovered. An interesting similarity between sea turtles and salmon is that both have been hypothesized to complete long-distance reproductive migrations using navigational systems composed of two different suites of mechanisms that function sequentially over different spatial scales. The basic organization of navigation in these two groups of animals may be functionally similar, and perhaps also representative of other long-distance ocean navigators.

Deep data fusion method for missile-borne inertial/celestial system

NASA Astrophysics Data System (ADS)

Zhang, Chunxi; Chen, Xiaofei; Lu, Jiazhen; Zhang, Hao

2018-05-01

Strap-down inertial-celestial integrated navigation system has the advantages of autonomy and high precision and is very useful for ballistic missiles. The star sensor installation error and inertial measurement error have a great influence for the system performance. Based on deep data fusion, this paper establishes measurement equations including star sensor installation error and proposes the deep fusion filter method. Simulations including misalignment error, star sensor installation error, IMU error are analyzed. Simulation results indicate that the deep fusion method can estimate the star sensor installation error and IMU error. Meanwhile, the method can restrain the misalignment errors caused by instrument errors.

Interplanetary approach optical navigation with applications

NASA Technical Reports Server (NTRS)

Jerath, N.

1978-01-01

The use of optical data from onboard television cameras for the navigation of interplanetary spacecraft during the planet approach phase is investigated. Three optical data types were studied: the planet limb with auxiliary celestial references, the satellite-star, and the planet-star two-camera methods. Analysis and modelling issues related to the nature and information content of the optical methods were examined. Dynamic and measurement system modelling, data sequence design, measurement extraction, model estimation and orbit determination, as relating optical navigation, are discussed, and the various error sources were analyzed. The methodology developed was applied to the Mariner 9 and the Viking Mars missions. Navigation accuracies were evaluated at the control and knowledge points, with particular emphasis devoted to the combined use of radio and optical data. A parametric probability analysis technique was developed to evaluate navigation performance as a function of system reliabilities.

Sensory integration: neuronal filters for polarized light patterns.

PubMed

Krapp, Holger G

2014-09-22

Animal and human behaviour relies on local sensory signals that are often ambiguous. A new study shows how tuning neuronal responses to celestial cues helps locust navigation, demonstrating a common principle of sensory information processing: the use of matched filters. Copyright © 2014 Elsevier Ltd. All rights reserved.

Study Stars - Morehead Planetarium

NASA Image and Video Library

1965-05-07

S65-29652 (7 May 1965) --- Astronauts James A. McDivitt (right) and Edward H. White II are shown at the Morehead Planetarium in North Carolina, checking out celestial navigation equipment as part of their training for the Gemini-Titan 4 mission. The NASA Headquarters alternative photo number is 65-H-277.

Celestial Navigation, with a Moral Compass.

ERIC Educational Resources Information Center

Donovan, Aine

1999-01-01

Kantian reasoning fails to address the needs of a mixed-gender peace-keeping force. A philosophy professor at the U.S. Naval Academy proposes a normative-ethics instructional model based on acceptance of duty and obedience (justice) and cultivation of reflective concern for individual choice and responsibility (caring). (24 references) (MLH)

Performance analysis of device-level SINS/ACFSS deeply integrated navigation method

NASA Astrophysics Data System (ADS)

Zhang, Hao; Qin, Shiqiao; Wang, Xingshu; Jiang, Guangwen; Tan, Wenfeng

2016-10-01

The Strap-Down Inertial Navigation System (SINS) is a widely used navigation system. The combination of SINS and the Celestial Navigation System (CNS) is one of the popular measures to constitute the integrated navigation system. A Star Sensor (SS) is used as a precise attitude determination device in CNS. To solve the problem that the star image obtained by SS under dynamic conditions is motion-blurred, the Attitude Correlated Frames (ACF) is presented and the star sensor which works based on ACF approach is named ACFSS. Depending on the ACF approach, a novel device-level SINS/ACFSS deeply integrated navigation method is proposed in this paper. Feedback to the ACF process from the error of the gyro is one of the typical characters of the SINS/CNS deeply integrated navigation method. Herein, simulation results have verified its validity and efficiency in improving the accuracy of gyro and it can be proved that this method is feasible in theory.

Daytime Celestial Navigation for the Novice

NASA Astrophysics Data System (ADS)

Sadler, Philip M.; Night, Christopher

2010-03-01

What kinds of astronomical lab activities can high school and college astronomy students carry out easily in daytime? The most impressive is the determination of latitude and longitude from observations of the Sun. The ``shooting of a noon sight'' and its ``reduction to a position'' grew to become a daily practice at the start of the 19th century1 following the perfection of the marine chronometer by John Harrison and its mass production.2 This technique is still practiced by navigators in this age of GPS. Indeed, the U.S. Coast Guard exams for ocean-going licenses include celestial navigation.3 These techniques continue to be used by the military and by private sailors as a backup to all-too-fallible and jammable electronic navigation systems. A sextant, a nautical almanac,4 special sight reduction tables,5 and involved calculations are needed to determine position to the nearest mile using the Sun, Moon, stars, or planets. Yet, finding latitude and longitude to better than 30 miles from measurements of the Sun's altitude is easily within the capability of those taking astronomy or physics for the first time by applying certain basic principles. Moreover, it shows a practical application of astronomy in use the world over. The streamlined method described here takes advantage of the similar level of accuracy of its three components: 1.Observations using a homemade quadrant6 (instead of a sextant), 2. Student-made graphs of the altitude of the Sun over a day7 (replacing lengthy calculation using sight reduction tables), and 3. An averaged 20-year analemma used to find the Sun's navigational coordinates8,9 (rather than the 300+ page Nautical Almanac updated yearly).

Autonomous optical navigation using nanosatellite-class instruments: a Mars approach case study

NASA Astrophysics Data System (ADS)

Enright, John; Jovanovic, Ilija; Kazemi, Laila; Zhang, Harry; Dzamba, Tom

2018-02-01

This paper examines the effectiveness of small star trackers for orbital estimation. Autonomous optical navigation has been used for some time to provide local estimates of orbital parameters during close approach to celestial bodies. These techniques have been used extensively on spacecraft dating back to the Voyager missions, but often rely on long exposures and large instrument apertures. Using a hyperbolic Mars approach as a reference mission, we present an EKF-based navigation filter suitable for nanosatellite missions. Observations of Mars and its moons allow the estimator to correct initial errors in both position and velocity. Our results show that nanosatellite-class star trackers can produce good quality navigation solutions with low position (<300 {m}) and velocity (<0.15 {m/s}) errors as the spacecraft approaches periapse.

JPL VLBI Analysis Center Report for 2012

NASA Technical Reports Server (NTRS)

Jacobs, Chris

2013-01-01

This report describes the activities of the JPL VLBI Analysis Center for the year 2012. The highlight of the year was the successful MSL rover Mars landing, which was supported by VLBI-based navigation using our combined spacecraft, celestial reference frame, terrestrial reference frame, earth orientation, and planetary ephemeris VLBI systems. We also supported several other missions with VLBI navigation measurements. A combined NASA-ESA network was demonstrated with first Ka-band fringes to ESA's Malargue, Argentina 35 m. We achieved first fringes with our new digital back end and Mark 5C recorders.

Conflicting evidence about long-distance animal navigation.

PubMed

Alerstam, Thomas

2006-08-11

Because of conflicting evidence about several fundamental issues, long-distance animal navigation has yet to be satisfactorily explained. Among the unsolved problems are the nature of genetic spatial control of migration and the relationships between celestial and magnetic compass mechanisms and between different map-related cues in orientation and homing, respectively. In addition, navigation is expected to differ between animal groups depending on sensory capabilities and ecological conditions. Evaluations based on modern long-term tracking techniques of the geometry of migration routes and individual migration history, combined with behavioral experiments and exploration of the sensory and genetic mechanisms, will be crucial for understanding the spatial principles that guide animals on their global journeys.

Insect Responses to Linearly Polarized Reflections: Orphan Behaviors Without Neural Circuits

PubMed Central

Heinloth, Tanja; Uhlhorn, Juliane; Wernet, Mathias F.

2018-01-01

The e-vector orientation of linearly polarized light represents an important visual stimulus for many insects. Especially the detection of polarized skylight by many navigating insect species is known to improve their orientation skills. While great progress has been made towards describing both the anatomy and function of neural circuit elements mediating behaviors related to navigation, relatively little is known about how insects perceive non-celestial polarized light stimuli, like reflections off water, leaves, or shiny body surfaces. Work on different species suggests that these behaviors are not mediated by the “Dorsal Rim Area” (DRA), a specialized region in the dorsal periphery of the adult compound eye, where ommatidia contain highly polarization-sensitive photoreceptor cells whose receptive fields point towards the sky. So far, only few cases of polarization-sensitive photoreceptors have been described in the ventral periphery of the insect retina. Furthermore, both the structure and function of those neural circuits connecting to these photoreceptor inputs remain largely uncharacterized. Here we review the known data on non-celestial polarization vision from different insect species (dragonflies, butterflies, beetles, bugs and flies) and present three well-characterized examples for functionally specialized non-DRA detectors from different insects that seem perfectly suited for mediating such behaviors. Finally, using recent advances from circuit dissection in Drosophila melanogaster, we discuss what types of potential candidate neurons could be involved in forming the underlying neural circuitry mediating non-celestial polarization vision. PMID:29615868

Skylore of the Indigenous Peoples of Northern Eurasia

NASA Astrophysics Data System (ADS)

Frank, Roslyn M.

This chapter examines the skylore of the indigenous peoples of northern Eurasia, paying particular attention to the commonalities found among them as well as the differences. Special attention is placed on the motif of the Cosmic Hunt and its diverse manifestations across the study area as well as on the oral nature of the celestial beliefs of these groups. The stars of a variety of "Western" constellation figures are implicated in the narratives and in some cases are clearly utilized in social practice for celestial navigation. The role played by the underlying hunter-gatherer mode of subsistence in shaping their cultural conceptualizations, their skyscapes, and the overarching cosmology of these peoples is also addressed.

Celestial dynamics and astrometry in expanding universe

NASA Astrophysics Data System (ADS)

Kopeikin, Sergei

2012-08-01

Post - Newtonian theory of motion of celestial bodies and propagation of light was instrumental in conducting the critical experimental tests of general relativity and in building the astronomical ephemerides of celestial bodies in the solar system with an unparalleled precision. The cornerstone of the theory is the postulate that the solar system is gravitationally isolated from the rest of the universe and the background spacetime is asymptotically flat. The present talk abolishes this postulate and lays down the principles of celestial dynamics of particles and light moving in gravitational field of a localized astronomical system embedded to the expanding universe. We formulate the precise mathematical concept of the Newtonian limit of Einstein ’s field equations in the conformally - flat spacetime and analyse the geodesic equations of motion o f particles and light in this limit. We demonstrate that the equations of motion of particles and light can be reduced to their Newtonian counterparts by doing conformal transformations of time and space coordinates. However, the Newtonian equations for particles and light differ by terms of the first order in the Hubble constant. This leads to the important conclusion that the equations of motion used currently by Space Navigation Centres and Astronomical Observatories for calculating orbits of celestial bodies, are incomplete and missing some terms of cosmological origin. We explicitly identify the missing terms and demonstrate that they bring about a noticeable discrepancy between the observed and calculated astronomical ephemerides. We argue that a number of observed celestial anomalies in the solar system can be explained as caused by the Hubble expansion of the universe.

The Role of Celestial Compass Information in Cataglyphis Ants during Learning Walks and for Neuroplasticity in the Central Complex and Mushroom Bodies

PubMed Central

Grob, Robin; Fleischmann, Pauline N.; Grübel, Kornelia; Wehner, Rüdiger; Rössler, Wolfgang

2017-01-01

Central place foragers are faced with the challenge to learn the position of their nest entrance in its surroundings, in order to find their way back home every time they go out to search for food. To acquire navigational information at the beginning of their foraging career, Cataglyphis noda performs learning walks during the transition from interior worker to forager. These small loops around the nest entrance are repeatedly interrupted by strikingly accurate back turns during which the ants stop and precisely gaze back to the nest entrance—presumably to learn the landmark panorama of the nest surroundings. However, as at this point the complete navigational toolkit is not yet available, the ants are in need of a reference system for the compass component of the path integrator to align their nest entrance-directed gazes. In order to find this directional reference system, we systematically manipulated the skylight information received by ants during learning walks in their natural habitat, as it has been previously suggested that the celestial compass, as part of the path integrator, might provide such a reference system. High-speed video analyses of distinct learning walk elements revealed that even exclusion from the skylight polarization pattern, UV-light spectrum and the position of the sun did not alter the accuracy of the look back to the nest behavior. We therefore conclude that C. noda uses a different reference system to initially align their gaze directions. However, a comparison of neuroanatomical changes in the central complex and the mushroom bodies before and after learning walks revealed that exposure to UV light together with a naturally changing polarization pattern was essential to induce neuroplasticity in these high-order sensory integration centers of the ant brain. This suggests a crucial role of celestial information, in particular a changing polarization pattern, in initially calibrating the celestial compass system. PMID:29184487

The Role of Celestial Compass Information in Cataglyphis Ants during Learning Walks and for Neuroplasticity in the Central Complex and Mushroom Bodies.

PubMed

Grob, Robin; Fleischmann, Pauline N; Grübel, Kornelia; Wehner, Rüdiger; Rössler, Wolfgang

2017-01-01

Central place foragers are faced with the challenge to learn the position of their nest entrance in its surroundings, in order to find their way back home every time they go out to search for food. To acquire navigational information at the beginning of their foraging career, Cataglyphis noda performs learning walks during the transition from interior worker to forager. These small loops around the nest entrance are repeatedly interrupted by strikingly accurate back turns during which the ants stop and precisely gaze back to the nest entrance-presumably to learn the landmark panorama of the nest surroundings. However, as at this point the complete navigational toolkit is not yet available, the ants are in need of a reference system for the compass component of the path integrator to align their nest entrance-directed gazes. In order to find this directional reference system, we systematically manipulated the skylight information received by ants during learning walks in their natural habitat, as it has been previously suggested that the celestial compass, as part of the path integrator, might provide such a reference system. High-speed video analyses of distinct learning walk elements revealed that even exclusion from the skylight polarization pattern, UV-light spectrum and the position of the sun did not alter the accuracy of the look back to the nest behavior. We therefore conclude that C. noda uses a different reference system to initially align their gaze directions. However, a comparison of neuroanatomical changes in the central complex and the mushroom bodies before and after learning walks revealed that exposure to UV light together with a naturally changing polarization pattern was essential to induce neuroplasticity in these high-order sensory integration centers of the ant brain. This suggests a crucial role of celestial information, in particular a changing polarization pattern, in initially calibrating the celestial compass system.

How the clear-sky angle of polarization pattern continues underneath clouds: full-sky measurements and implications for animal orientation.

PubMed

Pomozi, I; Horváth, G; Wehner, R

2001-09-01

One of the biologically most important parameters of the cloudy sky is the proportion P of the celestial polarization pattern available for use in animal navigation. We evaluated this parameter by measuring the polarization patterns of clear and cloudy skies using 180 degrees (full-sky) imaging polarimetry in the red (650 nm), green (550 nm) and blue (450 nm) ranges of the spectrum under clear and partly cloudy conditions. The resulting data were compared with the corresponding celestial polarization patterns calculated using the single-scattering Rayleigh model. We show convincingly that the pattern of the angle of polarization (e-vectors) in a clear sky continues underneath clouds if regions of the clouds and parts of the airspace between the clouds and the earth surface (being shady at the position of the observer) are directly lit by the sun. The scattering and polarization of direct sunlight on the cloud particles and in the air columns underneath the clouds result in the same e-vector pattern as that present in clear sky. This phenomenon can be exploited for animal navigation if the degree of polarization is higher than the perceptual threshold of the visual system, because the angle rather than the degree of polarization is the most important optical cue used in the polarization compass. Hence, the clouds reduce the extent of sky polarization pattern that is useful for animal orientation much less than has hitherto been assumed. We further demonstrate quantitatively that the shorter the wavelength, the greater the proportion of celestial polarization that can be used by animals under cloudy-sky conditions. As has already been suggested by others, this phenomenon may solve the ultraviolet paradox of polarization vision in insects such as hymenopterans and dipterans. The present study extends previous findings by using the technique of 180 degrees imaging polarimetry to measure and analyse celestial polarization patterns.

Maximum Correntropy Unscented Kalman Filter for Ballistic Missile Navigation System based on SINS/CNS Deeply Integrated Mode.

PubMed

Hou, Bowen; He, Zhangming; Li, Dong; Zhou, Haiyin; Wang, Jiongqi

2018-05-27

Strap-down inertial navigation system/celestial navigation system ( SINS/CNS) integrated navigation is a high precision navigation technique for ballistic missiles. The traditional navigation method has a divergence in the position error. A deeply integrated mode for SINS/CNS navigation system is proposed to improve the navigation accuracy of ballistic missile. The deeply integrated navigation principle is described and the observability of the navigation system is analyzed. The nonlinearity, as well as the large outliers and the Gaussian mixture noises, often exists during the actual navigation process, leading to the divergence phenomenon of the navigation filter. The new nonlinear Kalman filter on the basis of the maximum correntropy theory and unscented transformation, named the maximum correntropy unscented Kalman filter, is deduced, and the computational complexity is analyzed. The unscented transformation is used for restricting the nonlinearity of the system equation, and the maximum correntropy theory is used to deal with the non-Gaussian noises. Finally, numerical simulation illustrates the superiority of the proposed filter compared with the traditional unscented Kalman filter. The comparison results show that the large outliers and the influence of non-Gaussian noises for SINS/CNS deeply integrated navigation is significantly reduced through the proposed filter.

Experiment T002: Manual navigation sightings

NASA Technical Reports Server (NTRS)

Smith, D.

1971-01-01

Navigation-type measurements through the window of the stabilized Gemini 12 spacecraft by the use of a hand-held sextant are reported. The major objectives were as follows: (1) to evaluate the ability of the crewmen to make accurate navigational measurements by the use of simple instruments in an authentic space flight environment; (2) to evaluate the operational feasibility of the measurement techniques by the use of the pressure suit with the helmet off and with the helmet on and the visor closed; (3) to evaluate operational problems associated with the spacecraft environment; and (4) to validate ground based simulation techniques by comparison of the inflight results with base line data obtained by the pilot by the use of simulators and celestial targets from ground based observatories.

Daytime Celestial Navigation for the Novice

ERIC Educational Resources Information Center

Sadler, Philip M.; Night, Christopher

2010-01-01

What kinds of astronomical lab activities can high school and college astronomy students carry out easily in daytime? The most impressive is the determination of latitude and longitude from observations of the Sun. The "shooting of a noon sight" and its "reduction to a position" grew to become a daily practice at the start of the 19th century…

Astrodynamics. Volume 1 - Orbit determination, space navigation, celestial mechanics.

NASA Technical Reports Server (NTRS)

Herrick, S.

1971-01-01

Essential navigational, physical, and mathematical problems of space exploration are covered. The introductory chapters dealing with conic sections, orientation, and the integration of the two-body problem are followed by an introduction to orbit determination and design. Systems of units and constants, as well as ephemerides, representations, reference systems, and data are then dealt with. A detailed attention is given to rendezvous problems and to differential processes in observational orbit correction, and in rendezvous or guidance correction. Finally, the Laplacian methods for determining preliminary orbits, and the orbit methods of Lagrange, Gauss, and Gibbs are reviewed.

A Celestial Reference Frame at X/ka-Band (8.4/32 Ghz) for Deep Space Navigation

NASA Technical Reports Server (NTRS)

Jacobs, C. S.; Clark, J. E.; Garcia-Miro, C.; Horiuchi, S.; Romero-Wolf, A.; Snedeker, L.; Sotuela, I.

2012-01-01

Deep space tracking and navigation are done in a quasi-inertial reference frame based upon the angular positions of distant active galactic nuclei (AGN). These objects, which are found at extreme distances characterized by median redshifts of z = 1, are ideal for reference frame definition because they exhibit no measurable parallax or proper motion. They are thought to be powered by super massive black holes whose gravitational energy drives galactic sized relativistic jets. These jets produce synchrotron emissions which are detectable by modern radio techniques such as Very Long baseline Interferometry (VLBI).

In-motion initial alignment and positioning with INS/CNS/ODO integrated navigation system for lunar rovers

NASA Astrophysics Data System (ADS)

Lu, Jiazhen; Lei, Chaohua; Yang, Yanqiang; Liu, Ming

2017-06-01

Many countries have been paying great attention to space exploration, especially about the Moon and the Mars. Autonomous and high-accuracy navigation systems are needed for probers and rovers to accomplish missions. Inertial navigation system (INS)/celestial navigation system (CNS) based navigation system has been used widely on the lunar rovers. Initialization is a particularly important step for navigation. This paper presents an in-motion alignment and positioning method for lunar rovers by INS/CNS/odometer integrated navigation. The method can estimate not only the position and attitude errors, but also the biases of the accelerometers and gyros using the standard Kalman filter. The differences between the platform star azimuth, elevation angles and the computed star azimuth, elevation angles, and the difference between the velocity measured by odometer and the velocity measured by inertial sensors are taken as measurements. The semi-physical experiments are implemented to demonstrate that the position error can reduce to 10 m and attitude error is within 2″ during 5 min. The experiment results prove that it is an effective and attractive initialization approach for lunar rovers.

Stereotaxy, navigation and the temporal concatenation.

PubMed

Apuzzo, M L; Chen, J C

1999-01-01

Nautical and cerebral navigation share similar elements of functional need and similar developmental pathways. The need for orientation necessitates the development of appropriate concepts, and such concepts are dependent on technology for practical realization. Occasionally, a concept precedes technology in time and requires periods of delay for appropriate development. A temporal concatenation exists where time allows the additive as need, concept and technology ultimately provide an endpoint of elegant solution. Nautical navigation has proceeded through periods of dead reckoning and celestial navigation to satellite orientation with associated refinements of instrumentation and charts for guidance. Cerebral navigation has progressed from craniometric orientation and burr hole mounted guidance systems to simple rectolinear and arc-centered devices based on radiographs to guidance by complex anatomical and functional maps provided as an amalgam of modern imaging modes. These maps are now augmented by complex frame and frameless systems which allow not only precise orientation, but also point and volumetric action. These complex technical modalities required and developed in part from elements of maritime navigation that have been translated to cerebral navigation in a temporal concatenation. Copyright 2000 S. Karger AG, Basel

Spatial memory and navigation by honeybees on the scale of the foraging range

PubMed

Dyer

1996-01-01

Honeybees and other nesting animals face the problem of finding their way between their nest and distant feeding sites. Many studies have shown that insects can learn foraging routes in reference to both landmarks and celestial cues, but it is a major puzzle how spatial information obtained from these environmental features is encoded in memory. This paper reviews recent progress by my colleagues and me towards understanding three specific aspects of this problem in honeybees: (1) how bees learn the spatial relationships among widely separated locations in a familiar terrain; (2) how bees learn the pattern of movement of the sun over the day; and (3) whether, and if so how, bees learn the relationships between celestial cues and landmarks.

Polarised skylight and the landmark panorama provide night-active bull ants with compass information during route following.

PubMed

Reid, Samuel F; Narendra, Ajay; Hemmi, Jan M; Zeil, Jochen

2011-02-01

Navigating animals are known to use a number of celestial and terrestrial compass cues that allow them to determine and control their direction of travel. Which of the cues dominate appears to depend on their salience. Here we show that night-active bull ants attend to both the pattern of polarised skylight and the landmark panorama in their familiar habitat. When the two directional cues are in conflict, ants choose a compromise direction. However, landmark guidance appears to be the primary mechanism of navigation used by forager ants, with those cues in the direction of heading having the greatest influence on navigation. Different colonies respond to the removal of these cues to different degrees, depending on the directional information provided by the local landmark panorama. Interestingly, other parts of the surrounding panorama also influence foraging speed and accuracy, suggesting that they too play a role in navigation.

The search for reference sources for delta VLBI navigation of the Galileo spacecraft

NASA Technical Reports Server (NTRS)

Ulvestad, J. S.; Linfield, R. P.

1986-01-01

A comprehensive search was made in order to identify celestial radio sources that can be used as references for navigation of the Galileo spacecraft by means of VLBI observations. The astronomical literature was seached for potential navigation sources, and several VLBI experiments were performed to determine the suitability of those sources for navigation. The results of such work performed since mid-1983 is reported. A summary is presented of the source properties required, the procedures used to identify candidate sources, and the results of the observations of these sources. The lists of souces presented are not meant to be taken directly and used for VLBI navigation, but they do provide a means of identifying the radio sources that could be used at various positions along the Galileo trajectory. Since the reference sources nearest the critical points of Jupiter encounter and probe release are rather weak, it would be extremely beneficial to use a pair of 70-m antennas for the VLBI measurements.

The Development of a Simulator System and Hardware Test Bed for Deep Space X-Ray Navigation

NASA Astrophysics Data System (ADS)

Doyle, Patrick T.

2013-03-01

Currently, there is a considerable interest in developing technologies that will allow using photon measurements from celestial x-ray sources for deep space navigation. The impetus for this is that many envisioned future space missions will require spacecraft to have autonomous navigation capabilities. For missions close to Earth, Global Navigation Satellite Systems (GNSS) such as GPS are readily available for use, but for missions far from Earth, other alternatives must be provided. While existing systems such as the Deep Space Network (DSN) can be used, latencies associated with servicing a fleet of vehicles may not be compatible with some autonomous operations requiring timely updates of their navigation solution. Because of their somewhat predictable emissions, pulsars are the ideal candidates for x-ray sources that can be used to provide key parameters for navigation. Algorithms and simulation tools that will enable designing and analyzing x-ray navigation concepts are presented. The development of a compact x-ray detector system is pivotal to the eventual deployment of such navigation systems. Therefore, results of a high altitude balloon test to evaluate the design of a compact x-ray detector system are described as well.

Navigation.

PubMed

Wiltschko, Roswitha

2017-07-01

Experiments with migrating birds displaced during autumn migration outside their normal migration corridor reveal two different navigational strategies: adult migrants compensate for the displacement, and head towards their traditional wintering areas, whereas young first-time migrants continue in their migratory direction. Young birds are guided to their still unknown goal by a genetically coded migration program that indicates duration and direction(s) of the migratory flight by controlling the amount of migratory restlessness and the compass course(s) with respect to the geomagnetic field and celestial rotation. Adult migrants that have already wintered and are familiar with the goal area approach the goal by true navigation, specifically heading towards it and changing their course correspondingly after displacement. During their first journey, young birds experience the distribution of potential navigational factors en route and in their winter home, which allows them to truly navigate on their next migrations. The navigational factors used appear to include magnetic intensity as a component in their multi-modal navigational 'map'; olfactory input is also involved, even if it is not yet entirely clear in what way. The mechanisms of migratory birds for true navigation over long distances appear to be in principle similar to those discussed for by homing pigeons.

Gravity

NASA Astrophysics Data System (ADS)

Poisson, Eric; Will, Clifford M.

2014-05-01

Preface; 1. Foundations of Newtonian gravity; 2. Structure of self-gravitating bodies; 3. Newtonian orbital dynamics; 4. Minkowski spacetime; 5. Curved spacetime; 6. Post-Minkowskian theory: formulation; 7. Post-Minkowskian theory: implementation; 8. Post-Newtonian theory: fundamentals; 9. Post-Newtonian theory: system of isolated bodies; 10. Post-Newtonian celestial mechanics, astrometry and navigation; 11. Gravitational waves; 12. Radiative losses and radiation reaction; 13. Alternative theories of gravity; References; Index.

Celestial Navigation in the 21st Century

NASA Astrophysics Data System (ADS)

Kaplan, George H.

2014-05-01

Despite the ubiquity of GPS receivers in modern life for both timekeeping and geolocation, other forms of navigation remain important because of the weakness of the GPS signals (and those from similar sat-nav systems) and the ease with which they can be jammed. GPS jammers are available for sale on the Internet. The defense and civil aviation communities are particularly concerned about “GPS denial”, whether intentional or accidental, during critical operations.Automated star trackers for navigation have been available since the 1950s. Modern compact observing systems, operating in the far-red and near-IR bands, can detect useful numbers of stars even in the daytime at sea level. A capability to measure the directions of stars relative to some local set of coordinate axes is advantageous for many types of vehicles, whether on the ground, at sea, in the air, or in space, because it provides a direct connection to the inertial reference system represented by current star catalogs. Such a capability can yield precise absolute orientation information not available in any other way. Automated celestial observing systems can be effectively coupled to inertial navigation systems (INS), providing “truth” data for constraining the drift in the INS navigation solution, even if stellar observations are not continuously available due to weather. However, obtaining precise latitude and longitude from stellar observations alone, on a moving platform, remains a challenge, because it requires a determination of the direction to the center of the Earth, i.e., the gravity vertical. General relativity tells us that on-board (“lab”) measurements cannot separate the acceleration of gravity from the acceleration of the platform. Various schemes for overcoming this fundamental problem have been used in the past, at low accuracy, and better ones have been proposed for modern applications. This paper will review some recent developments in this rapidly advancing field.

A novel autonomous real-time position method based on polarized light and geomagnetic field.

PubMed

Wang, Yinlong; Chu, Jinkui; Zhang, Ran; Wang, Lu; Wang, Zhiwen

2015-04-08

Many animals exploit polarized light in order to calibrate their magnetic compasses for navigation. For example, some birds are equipped with biological magnetic and celestial compasses enabling them to migrate between the Western and Eastern Hemispheres. The Vikings' ability to derive true direction from polarized light is also widely accepted. However, their amazing navigational capabilities are still not completely clear. Inspired by birds' and Vikings' ancient navigational skills. Here we present a combined real-time position method based on the use of polarized light and geomagnetic field. The new method works independently of any artificial signal source with no accumulation of errors and can obtain the position and the orientation directly. The novel device simply consists of two polarized light sensors, a 3-axis compass and a computer. The field experiments demonstrate device performance.

A novel autonomous real-time position method based on polarized light and geomagnetic field

PubMed Central

Wang, Yinlong; Chu, Jinkui; Zhang, Ran; Wang, Lu; Wang, Zhiwen

2015-01-01

Many animals exploit polarized light in order to calibrate their magnetic compasses for navigation. For example, some birds are equipped with biological magnetic and celestial compasses enabling them to migrate between the Western and Eastern Hemispheres. The Vikings' ability to derive true direction from polarized light is also widely accepted. However, their amazing navigational capabilities are still not completely clear. Inspired by birds' and Vikings' ancient navigational skills. Here we present a combined real-time position method based on the use of polarized light and geomagnetic field. The new method works independently of any artificial signal source with no accumulation of errors and can obtain the position and the orientation directly. The novel device simply consists of two polarized light sensors, a 3-axis compass and a computer. The field experiments demonstrate device performance. PMID:25851793

A novel autonomous real-time position method based on polarized light and geomagnetic field

NASA Astrophysics Data System (ADS)

Wang, Yinlong; Chu, Jinkui; Zhang, Ran; Wang, Lu; Wang, Zhiwen

2015-04-01

Many animals exploit polarized light in order to calibrate their magnetic compasses for navigation. For example, some birds are equipped with biological magnetic and celestial compasses enabling them to migrate between the Western and Eastern Hemispheres. The Vikings' ability to derive true direction from polarized light is also widely accepted. However, their amazing navigational capabilities are still not completely clear. Inspired by birds' and Vikings' ancient navigational skills. Here we present a combined real-time position method based on the use of polarized light and geomagnetic field. The new method works independently of any artificial signal source with no accumulation of errors and can obtain the position and the orientation directly. The novel device simply consists of two polarized light sensors, a 3-axis compass and a computer. The field experiments demonstrate device performance.

Integrated Navigation System Design for Micro Planetary Rovers: Comparison of Absolute Heading Estimation Algorithms and Nonlinear Filtering

PubMed Central

Ilyas, Muhammad; Hong, Beomjin; Cho, Kuk; Baeg, Seung-Ho; Park, Sangdeok

2016-01-01

This paper provides algorithms to fuse relative and absolute microelectromechanical systems (MEMS) navigation sensors, suitable for micro planetary rovers, to provide a more accurate estimation of navigation information, specifically, attitude and position. Planetary rovers have extremely slow speed (~1 cm/s) and lack conventional navigation sensors/systems, hence the general methods of terrestrial navigation may not be applicable to these applications. While relative attitude and position can be tracked in a way similar to those for ground robots, absolute navigation information is hard to achieve on a remote celestial body, like Moon or Mars, in contrast to terrestrial applications. In this study, two absolute attitude estimation algorithms were developed and compared for accuracy and robustness. The estimated absolute attitude was fused with the relative attitude sensors in a framework of nonlinear filters. The nonlinear Extended Kalman filter (EKF) and Unscented Kalman filter (UKF) were compared in pursuit of better accuracy and reliability in this nonlinear estimation problem, using only on-board low cost MEMS sensors. Experimental results confirmed the viability of the proposed algorithms and the sensor suite, for low cost and low weight micro planetary rovers. It is demonstrated that integrating the relative and absolute navigation MEMS sensors reduces the navigation errors to the desired level. PMID:27223293

Navigating oceans and cultures: Polynesian and European navigation systems in the late eighteenth century

NASA Astrophysics Data System (ADS)

Walker, M.

2012-05-01

Significant differences in the rotation of the celestial dome between the tropical and temperate zones did not stop the peoples of either the tropical Pacific or temperate Europe from using geocentric astronomy to guide exploration of the oceans. Although the differences in the night sky contributed to differences between the Pacific Island and European systems for navigation at sea, the two navigation systems exhibit substantial similarities. Both systems define positions on the surface of the Earth using two coordinates that vary at right angles to each other and use stars, and to a lesser extent the sun, to determine directions. This essay explores similarities and differences in the use of geocentric astronomy for navigation at sea by the peoples of Polynesia and Europe in the late eighteenth century. Captain Cook's orders to discover the unknown southern continent after observing the transit of Venus combined with differences in language and culture to obscure the deeper similarities between the navigation systems used by Cook and the Polynesians. Although it was a further 200 years before anthropologists studied Pacific navigation, collaborations in voyaging with communities in Oceania demonstrated the effectiveness of Pacific navigation systems, revived interest in traditional voyaging in island communities around the Pacific, and potentially open the way for further collaborations in other areas.

Integrated Navigation System Design for Micro Planetary Rovers: Comparison of Absolute Heading Estimation Algorithms and Nonlinear Filtering.

PubMed

Ilyas, Muhammad; Hong, Beomjin; Cho, Kuk; Baeg, Seung-Ho; Park, Sangdeok

2016-05-23

This paper provides algorithms to fuse relative and absolute microelectromechanical systems (MEMS) navigation sensors, suitable for micro planetary rovers, to provide a more accurate estimation of navigation information, specifically, attitude and position. Planetary rovers have extremely slow speed (~1 cm/s) and lack conventional navigation sensors/systems, hence the general methods of terrestrial navigation may not be applicable to these applications. While relative attitude and position can be tracked in a way similar to those for ground robots, absolute navigation information is hard to achieve on a remote celestial body, like Moon or Mars, in contrast to terrestrial applications. In this study, two absolute attitude estimation algorithms were developed and compared for accuracy and robustness. The estimated absolute attitude was fused with the relative attitude sensors in a framework of nonlinear filters. The nonlinear Extended Kalman filter (EKF) and Unscented Kalman filter (UKF) were compared in pursuit of better accuracy and reliability in this nonlinear estimation problem, using only on-board low cost MEMS sensors. Experimental results confirmed the viability of the proposed algorithms and the sensor suite, for low cost and low weight micro planetary rovers. It is demonstrated that integrating the relative and absolute navigation MEMS sensors reduces the navigation errors to the desired level.

32 GHz Celestial Reference Frame Survey for Dec < -45 deg.

NASA Astrophysics Data System (ADS)

Horiuchi, Shinji; Phillips, Chris; Stevens, Jamie; Jacobs, Christopher; Sotuela, Ioana; Garcia miro, Cristina

2013-04-01

(We resubmit this proposal to extend from the previous semester. The 24 hour blocks for ATCA and Mopra were granted in May 2012 but canceled because fringe test before the scheduled experiment failed although fringes were detected between Mopra and Tidbinbilla. As it turned out ATCA had an issue with frequency standard, which has now been resolved.) We propose to conduct a LBA survey of compact radio sources at 32 GHz near the south pole region. This is the first attempt to fill the gap in the existing 32 GHz catalogue establish by NASA Deep Space Network toward completing the full sky celestial reference frame at 32 GHz. The catalogue will be used for future spacecraft navigation by NASA and other space agencies as well as for radio astronomical observations with southern radio telescope arrays such as ATCA and LBA.

Apollo 13 - Prime Crew Portrait

NASA Image and Video Library

1969-12-11

S69-62224 (December 1969) --- The members of the prime crew of the Apollo 13 lunar landing mission (left to right) are astronauts James A. Lovell Jr., commander; Thomas K. Mattingly II, command module pilot; and Fred W. Haise Jr., lunar module pilot. They are seated in front of a scene of the Lagoon Nebula, with the mission insignia and two items of early navigation in the foreground. Represented in the Apollo 13 emblem (center) is Apollo, the sun god of Greek mythology, symbolizing that the Apollo flights have extended the light of knowledge to all mankind. The Latin phrase Ex Luna, Scientia means "From the Moon, Knowledge." The Hindu astrolabe in Sanskrit (on right) was used to predict the position of celestial bodies before the invention of the octant (on left) was used in 1790 to determine the altitude of celestial bodies from aboard ship.

How Ants Use Vision When Homing Backward.

PubMed

Schwarz, Sebastian; Mangan, Michael; Zeil, Jochen; Webb, Barbara; Wystrach, Antoine

2017-02-06

Ants can navigate over long distances between their nest and food sites using visual cues [1, 2]. Recent studies show that this capacity is undiminished when walking backward while dragging a heavy food item [3-5]. This challenges the idea that ants use egocentric visual memories of the scene for guidance [1, 2, 6]. Can ants use their visual memories of the terrestrial cues when going backward? Our results suggest that ants do not adjust their direction of travel based on the perceived scene while going backward. Instead, they maintain a straight direction using their celestial compass. This direction can be dictated by their path integrator [5] but can also be set using terrestrial visual cues after a forward peek. If the food item is too heavy to enable body rotations, ants moving backward drop their food on occasion, rotate and walk a few steps forward, return to the food, and drag it backward in a now-corrected direction defined by terrestrial cues. Furthermore, we show that ants can maintain their direction of travel independently of their body orientation. It thus appears that egocentric retinal alignment is required for visual scene recognition, but ants can translate this acquired directional information into a holonomic frame of reference, which enables them to decouple their travel direction from their body orientation and hence navigate backward. This reveals substantial flexibility and communication between different types of navigational information: from terrestrial to celestial cues and from egocentric to holonomic directional memories. VIDEO ABSTRACT. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

A high-accuracy two-position alignment inertial navigation system for lunar rovers aided by a star sensor with a calibration and positioning function

NASA Astrophysics Data System (ADS)

Lu, Jiazhen; Lei, Chaohua; Yang, Yanqiang; Liu, Ming

2016-12-01

An integrated inertial/celestial navigation system (INS/CNS) has wide applicability in lunar rovers as it provides accurate and autonomous navigational information. Initialization is particularly vital for a INS. This paper proposes a two-position initialization method based on a standard Kalman filter. The difference between the computed star vector and the measured star vector is measured. With the aid of a star sensor and the two positions, the attitudinal and positional errors can be greatly reduced, and the biases of three gyros and accelerometers can also be estimated. The semi-physical simulation results show that the positional and attitudinal errors converge within 0.07″ and 0.1 m, respectively, when the given initial positional error is 1 km and the attitudinal error is 10°. These good results show that the proposed method can accomplish alignment, positioning and calibration functions simultaneously. Thus the proposed two-position initialization method has the potential for application in lunar rover navigation.

Integrated communications and optical navigation system

NASA Astrophysics Data System (ADS)

Mueller, J.; Pajer, G.; Paluszek, M.

2013-12-01

The Integrated Communications and Optical Navigation System (ICONS) is a flexible navigation system for spacecraft that does not require global positioning system (GPS) measurements. The navigation solution is computed using an Unscented Kalman Filter (UKF) that can accept any combination of range, range-rate, planet chord width, landmark, and angle measurements using any celestial object. Both absolute and relative orbit determination is supported. The UKF employs a full nonlinear dynamical model of the orbit including gravity models and disturbance models. The ICONS package also includes attitude determination algorithms using the UKF algorithm with the Inertial Measurement Unit (IMU). The IMU is used as the dynamical base for the attitude determination algorithms. This makes the sensor a more capable plug-in replacement for a star tracker, thus reducing the integration and test cost of adding this sensor to a spacecraft. Recent additions include an integrated optical communications system which adds communications, and integrated range and range rate measurement and timing. The paper includes test results from trajectories based on the NASA New Horizons spacecraft.

Receptive fields of locust brain neurons are matched to polarization patterns of the sky.

PubMed

Bech, Miklós; Homberg, Uwe; Pfeiffer, Keram

2014-09-22

Many animals, including insects, are able to use celestial cues as a reference for spatial orientation and long-distance navigation [1]. In addition to direct sunlight, the chromatic gradient of the sky and its polarization pattern are suited to serve as orientation cues [2-5]. Atmospheric scattering of sunlight causes a regular pattern of E vectors in the sky, which are arranged along concentric circles around the sun [5, 6]. Although certain insects rely predominantly on sky polarization for spatial orientation [7], it has been argued that detection of celestial E vector orientation may not suffice to differentiate between solar and antisolar directions [8, 9]. We show here that polarization-sensitive (POL) neurons in the brain of the desert locust Schistocerca gregaria can overcome this ambiguity. Extracellular recordings from POL units in the central complex and lateral accessory lobes revealed E vector tunings arranged in concentric circles within large receptive fields, matching the sky polarization pattern at certain solar positions. Modeling of neuronal responses under an idealized sky polarization pattern (Rayleigh sky) suggests that these "matched filter" properties allow locusts to unambiguously determine the solar azimuth by relying solely on the sky polarization pattern for compass navigation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Common features in diverse insect clocks.

PubMed

Numata, Hideharu; Miyazaki, Yosuke; Ikeno, Tomoko

2015-01-01

This review describes common features among diverse biological clocks in insects, including circadian, circatidal, circalunar/circasemilunar, and circannual clocks. These clocks control various behaviors, physiological functions, and developmental events, enabling adaptation to periodic environmental changes. Circadian clocks also function in time-compensation for celestial navigation and in the measurement of day or night length for photoperiodism. Phase response curves for such clocks reported thus far exhibit close similarities; specifically, the circannual clock in Anthrenus verbasci shows striking similarity to circadian clocks in its phase response. It is suggested that diverse biological clocks share physiological properties in their phase responses irrespective of period length. Molecular and physiological mechanisms are best understood for the optic-lobe and mid-brain circadian clocks, although there is no direct evidence that these clocks are involved in rhythmic phenomena other than circadian rhythms in daily events. Circadian clocks have also been localized in peripheral tissues, and research on their role in various rhythmic phenomena has been started. Although clock genes have been identified as controllers of circadian rhythms in daily events, some of these genes have also been shown to be involved in photoperiodism and possibly in time-compensated celestial navigation. In contrast, there is no experimental evidence indicating that any known clock gene is involved in biological clocks other than circadian clocks.

Dramatic orientation shift of white-crowned sparrows displaced across longitudes in the high Arctic.

PubMed

Akesson, Susanne; Morin, Jens; Muheim, Rachel; Ottosson, Ulf

2005-09-06

Advanced spatial-learning adaptations have been shown for migratory songbirds, but it is not well known how the simple genetic program encoding migratory distance and direction in young birds translates to a navigation mechanism used by adults. A number of convenient cues are available to define latitude on the basis of geomagnetic and celestial information, but very few are useful to defining longitude. To investigate the effects of displacements across longitudes on orientation, we recorded orientation of adult and juvenile migratory white-crowned sparrows, Zonotrichia leucophrys gambelii, after passive longitudinal displacements, by ship, of 266-2862 km across high-arctic North America. After eastward displacement to the magnetic North Pole and then across the 0 degrees declination line, adults and juveniles abruptly shifted their orientation from the migratory direction to a direction that would lead back to the breeding area or to the normal migratory route, suggesting that the birds began compensating for the displacement by using geomagnetic cues alone or together with solar cues. In contrast to predictions by a simple genetic migration program, our experiments suggest that both adults and juveniles possess a navigation system based on a combination of celestial and geomagnetic information, possibly declination, to correct for eastward longitudinal displacements.

Neural mechanisms in insect navigation: polarization compass and odometer.

PubMed

Labhart, Thomas; Meyer, Eric P

2002-12-01

Insect navigation relies on path integration, a procedure by which information about compass bearings pursued and distances travelled are combined to calculate position. Three neural levels of the polarization compass, which uses the polarization of skylight as a reference, have been analyzed in orthopteran insects. A group of dorsally directed, highly specialized ommatidia serve as polarization sensors. Polarization-opponent neurons in the optic lobe condition the polarization signal by removing unreliable and irrelevant components of the celestial stimulus. Neurons found in the central complex of the brain possibly represent elements of the compass output. The odometer for measuring travelling distances in honeybees relies on optic flow experienced during flight, whereas desert ants most probably use proprioreceptive cues.

Coupled solar-magnetic orientation during leatherback turtle (Dermochelys coriacea), great white shark (Carcharodon carcharias), arctic tern (Sterna paradisaea), and humpback whale (Megaptera novaeangliae) long-distance migration

NASA Astrophysics Data System (ADS)

Horton, T. W.; Holdaway, R. N.; Zerbini, A.; Andriolo, A.; Clapham, P. J.

2010-12-01

Determining how animals perform long-distance animal migration remains one of the most enduring and fundamental mysteries of behavioural ecology. It is widely accepted that navigation relative to a reference datum is a fundamental requirement of long-distance return migration between seasonal habitats, and significant experimental research has documented a variety of viable orientation and navigation cues. However, relatively few investigations have attempted to reconcile experimentally determined orientation and navigation capacities of animals with empirical remotely sensed animal track data, leaving most theories of navigation and orientation untested. Here we show, using basic hypothesis testing, that leatherback turtle (Dermochelys coriacea), great white shark (Carcharodon carcharias), arctic tern (Sterna paradisaea), and humpback whale (Megaptera novaeangliae) migration paths are non-randomly distributed in magnetic coordinate space, with local peaks in magnetic coordinate distributions equal to fractional multiples of the angular obliquity of Earth’s axis of rotation. Time series analysis of humpback whale migratory behaviours, including migration initiation, changes in course, and migratory stop-overs, further demonstrate coupling of magnetic and celestial orientation cues during long-distance migration. These unexpected and highly novel results indicate that diverse taxa integrate magnetic and celestial orientation cues during long-distance migration. These results are compatible with a 'map and compass' orientation and navigation system. Humpback whale migration track geometries further indicate a map and compass orientation system is used. Several humpback whale tracks include highly directional segments (Mercator latitude vs. longitude r2>0.99) exceeding 2000 km in length, despite exposure to variable strength (c. 0-1 km/hr) surface cross-currents. Humpback whales appear to be able to compensate for surface current drift. The remarkable directional precision of these humpback whale track segments is far better than the ±25°-40° precision of the avian magnetic compass. The positional and directional orientation data presented suggests signal transduction provides spatial information to migrating animals with better than 1° precision.

Time References in US and UK Astronomical and Navigational Almanacs

DTIC Science & Technology

2011-01-01

are also compatible with Teph and TDB. 2.4. Terrestrial and Barycentric Dynamic Times An apparent place, or equivalently the geocentric intermediate...right ascension and declination with respect to the CIO and equator of date, is defined in the Geocentric Celestial Reference System where the... Geocentric Coordinate Time (TCG) nor Barycentric Coordinate Time (TCB) is used in the US and UK almanacs for different reasons. TCG is a coordinate time

Celestial Pattern Recognition Allowing Autonomous Earth-Surface or Deep-Space Positioning.

DTIC Science & Technology

1983-12-01

viii :% -7 .2 I. INTRODUCTION AND BACKGROUND Background of the Project This research project is conceptual and opportunistic. It is conceptual in that...alternative approaches and the usefulness of a device in different navigation regimes. Both the research and this report have tried to follow these...Packard, Potter, and Viglione (Ref 2; 7; 15; 17; 23) have published papers (most of these 20 years ago) suggesting that some form of star

32 GHz Celestial Reference Frame Survey for Dec < -45 deg.

NASA Astrophysics Data System (ADS)

Horiuchi, Shinji; Phillips, Chris; Stevens, Jamie; Jacobs, Christopher; Sotuela, Ioana; Garcia miro, Cristina

2014-04-01

(We resubmit this proposal to extend from the previous semester. The 24 hour blocks for ATCA and Mopra were granted in May 2012 but canceled because fringe test before the scheduled experiment failed although fringes were detected between Mopra and Tidbinbilla. During the last scheduled LBA session for this project we discovered ATCA/Mopra had an issue with frequency standard, which has now been resolved.) We propose to conduct a LBA survey of compact radio sources at 32 GHz near the south pole region. This is the first attempt to fill the gap in the existing 32 GHz catalogue establish by NASA Deep Space Network toward completing the full sky celestial reference frame at 32 GHz. The catalogue will be used for future spacecraft navigation by NASA and other space agencies as well as for radio astronomical observations with southern radio telescope arrays such as ATCA and LBA.

The Celestial Reference Frame at X/Ka-band (8.4/32 GHz)

NASA Technical Reports Server (NTRS)

Jacobs, C. S.; Clark, J. E.; Heflin, M. B.; Skjerve, L. J.; Sovers, O. J.; Garcia-Miro, C.; Moll, V. E.; Horiuchi, S.

2011-01-01

A celestial reference frame at X/Ka-band (8.4/32 GHz) has been constructed using fifty-one 24-hour sessions with the Deep Space Network. We report on observations which have detected 436 sources covering the full 24 hours of right ascension and declinations down to -45 deg. Comparison of this X/Ka-band frame to the S/X-band (2.3/8.4 GHz) ICRF2 shows wRMS agreement of 200 micro-arcsec in a cos delta and 290 micro-arcsec in delta. There is evidence for zonal errors at the 100 micro-arcsec level. Known errors include limited SNR, lack of phase calibration, troposphere mismodelling, and limited southern geometry. The motivations for extending the ICRF to frequencies above 8 GHz are to access more compact source morphology for improved frame stability, to provide calibrators for phase referencing, and to support spacecraft navigation at Ka-band.

The Celestial Reference Frame at X/Ka-band (8.4/32 GHz)

NASA Technical Reports Server (NTRS)

Jacobs, C. S.; Clark, J. E.; Heflin, M. B.; Skjerve, L. J.; Sovers, O. J.; Garcia-Miro, C.; Moll, V. E.; Horiuchi, S.

2010-01-01

A celestial reference frame at X/Kaband (8.4/32 GHz) has been constructed using fiftyone 24-hour sessions with the Deep Space Network. We report on observations which have detected 436 sources covering the full 24 hours of right ascension and declinations down to -45 deg. Comparison of this X/Ka-band frame to the S/X-band (2.3/8.4 GHz) ICRF2 shows wRMS agreement of 200 micro-arcsec ( mu as) in alpha cos delta and 290 mu as in delta. There is evidence for zonal errors at the 100 mu as level. Known errors include limited SNR, lack of phase calibration, troposphere mismodelling, and limited southern geometry. The motivations for extending the ICRF to frequencies above 8 GHz are to access more compact source morphology for improved frame stability, to provide calibrators for phase referencing, and to support spacecraft navigation at Ka-band.

Visual orientation and navigation in nocturnal arthropods.

PubMed

Warrant, Eric; Dacke, Marie

2010-01-01

With their highly sensitive visual systems, the arthropods have evolved a remarkable capacity to orient and navigate at night. Whereas some navigate under the open sky, and take full advantage of the celestial cues available there, others navigate in more difficult conditions, such as through the dense understory of a tropical rainforest. Four major classes of orientation are performed by arthropods at night, some of which involve true navigation (i.e. travel to a distant goal that lies beyond the range of direct sensory contact): (1) simple straight-line orientation, typically for escape purposes; (2) nightly short-distance movements relative to a shoreline, typically in the context of feeding; (3) long-distance nocturnal migration at high altitude in the quest to locate favorable feeding or breeding sites, and (4) nocturnal excursions to and from a fixed nest or food site (i.e. homing), a task that in most species involves path integration and/or the learning and recollection of visual landmarks. These four classes of orientation--and their visual basis--are reviewed here, with special emphasis given to the best-understood animal systems that are representative of each. 2010 S. Karger AG, Basel.

The ontogenetic development of orientation capabilities

NASA Technical Reports Server (NTRS)

Emlen, S. T.

1972-01-01

The effects of celestial references on the navigation ability of birds are discussed. Tests were conducted in a planetarium with indigo buntings to determine the amount of stellar pattern which could be removed before disorientation occurred. It was determined that young birds have a predisposition to respond to the apparent rotational motion of the night sky. It was concluded that the peak in responsiveness to rotational information is presented during the first summer of life, prior to the first migration season.

Determination of the Beagle2 landing site

NASA Astrophysics Data System (ADS)

Trautner, R.; Manaud, N.; Michael, G.; Griffiths, A.; Beauvivre, S.; Koschny, D.; Coates, A.; Josset, J.-L.

2004-02-01

Beagle2 is the UK-led lander element on ESA's Mars Express mission, which will reach Mars in late December 2003. After separation from the Mars Express orbiter 6 days before the atmospheric entry, Beagle2 will descend to the Martian surface by means of ablative heat shields and parachutes. The impact will be cushioned by a set of airbags. The selected landing site at 11.6 deg N/90.75 deg E (IAU 2000 coordinates) is situated in the south-east of the center of Isidis Planitia, a sedimentary basin which is expected to meet the requirements of Beagle's scientific mission, the lander operations, and the entry, descent and landing systems. The exact determination of the Beagle2 landing site is important not only for the Beagle2 and MEX orbiter science investigations, but also for the reconstruction of Beagle's entry and descent trajectory. A precise determination of the Beagle2 position is not possible via the MELACOM radio link. Instead, a novel method based on celestial navigation is employed, which utilizes the Stereo Camera System on the lander for imaging the Martian night sky. The position data is then refined by comparing the landing site panorama images with high resolution orbiter images and laser altimeter data. This combination of celestial navigation with image data analysis for precision position determination will be applicable for many future missions as well.

Multi-Sensor Optimal Data Fusion Based on the Adaptive Fading Unscented Kalman Filter

PubMed Central

Gao, Bingbing; Hu, Gaoge; Gao, Shesheng; Gu, Chengfan

2018-01-01

This paper presents a new optimal data fusion methodology based on the adaptive fading unscented Kalman filter for multi-sensor nonlinear stochastic systems. This methodology has a two-level fusion structure: at the bottom level, an adaptive fading unscented Kalman filter based on the Mahalanobis distance is developed and serves as local filters to improve the adaptability and robustness of local state estimations against process-modeling error; at the top level, an unscented transformation-based multi-sensor optimal data fusion for the case of N local filters is established according to the principle of linear minimum variance to calculate globally optimal state estimation by fusion of local estimations. The proposed methodology effectively refrains from the influence of process-modeling error on the fusion solution, leading to improved adaptability and robustness of data fusion for multi-sensor nonlinear stochastic systems. It also achieves globally optimal fusion results based on the principle of linear minimum variance. Simulation and experimental results demonstrate the efficacy of the proposed methodology for INS/GNSS/CNS (inertial navigation system/global navigation satellite system/celestial navigation system) integrated navigation. PMID:29415509

Multi-Sensor Optimal Data Fusion Based on the Adaptive Fading Unscented Kalman Filter.

PubMed

Gao, Bingbing; Hu, Gaoge; Gao, Shesheng; Zhong, Yongmin; Gu, Chengfan

2018-02-06

This paper presents a new optimal data fusion methodology based on the adaptive fading unscented Kalman filter for multi-sensor nonlinear stochastic systems. This methodology has a two-level fusion structure: at the bottom level, an adaptive fading unscented Kalman filter based on the Mahalanobis distance is developed and serves as local filters to improve the adaptability and robustness of local state estimations against process-modeling error; at the top level, an unscented transformation-based multi-sensor optimal data fusion for the case of N local filters is established according to the principle of linear minimum variance to calculate globally optimal state estimation by fusion of local estimations. The proposed methodology effectively refrains from the influence of process-modeling error on the fusion solution, leading to improved adaptability and robustness of data fusion for multi-sensor nonlinear stochastic systems. It also achieves globally optimal fusion results based on the principle of linear minimum variance. Simulation and experimental results demonstrate the efficacy of the proposed methodology for INS/GNSS/CNS (inertial navigation system/global navigation satellite system/celestial navigation system) integrated navigation.

Polarized light use in the nocturnal bull ant, Myrmecia midas.

PubMed

Freas, Cody A; Narendra, Ajay; Lemesle, Corentin; Cheng, Ken

2017-08-01

Solitary foraging ants have a navigational toolkit, which includes the use of both terrestrial and celestial visual cues, allowing individuals to successfully pilot between food sources and their nest. One such celestial cue is the polarization pattern in the overhead sky. Here, we explore the use of polarized light during outbound and inbound journeys and with different home vectors in the nocturnal bull ant, Myrmecia midas . We tested foragers on both portions of the foraging trip by rotating the overhead polarization pattern by ±45°. Both outbound and inbound foragers responded to the polarized light change, but the extent to which they responded to the rotation varied. Outbound ants, both close to and further from the nest, compensated for the change in the overhead e-vector by about half of the manipulation, suggesting that outbound ants choose a compromise heading between the celestial and terrestrial compass cues. However, ants returning home compensated for the change in the e-vector by about half of the manipulation when the remaining home vector was short (1-2 m) and by more than half of the manipulation when the remaining vector was long (more than 4 m). We report these findings and discuss why weighting on polarization cues change in different contexts.

Polarized light use in the nocturnal bull ant, Myrmecia midas

PubMed Central

Lemesle, Corentin; Cheng, Ken

2017-01-01

Solitary foraging ants have a navigational toolkit, which includes the use of both terrestrial and celestial visual cues, allowing individuals to successfully pilot between food sources and their nest. One such celestial cue is the polarization pattern in the overhead sky. Here, we explore the use of polarized light during outbound and inbound journeys and with different home vectors in the nocturnal bull ant, Myrmecia midas. We tested foragers on both portions of the foraging trip by rotating the overhead polarization pattern by ±45°. Both outbound and inbound foragers responded to the polarized light change, but the extent to which they responded to the rotation varied. Outbound ants, both close to and further from the nest, compensated for the change in the overhead e-vector by about half of the manipulation, suggesting that outbound ants choose a compromise heading between the celestial and terrestrial compass cues. However, ants returning home compensated for the change in the e-vector by about half of the manipulation when the remaining home vector was short (1−2 m) and by more than half of the manipulation when the remaining vector was long (more than 4 m). We report these findings and discuss why weighting on polarization cues change in different contexts. PMID:28879002

The use of x-ray pulsar-based navigation method for interplanetary flight

NASA Astrophysics Data System (ADS)

Yang, Bo; Guo, Xingcan; Yang, Yong

2009-07-01

As interplanetary missions are increasingly complex, the existing unique mature interplanetary navigation method mainly based on radiometric tracking techniques of Deep Space Network can not meet the rising demands of autonomous real-time navigation. This paper studied the applications for interplanetary flights of a new navigation technology under rapid development-the X-ray pulsar-based navigation for spacecraft (XPNAV), and valued its performance with a computer simulation. The XPNAV is an excellent autonomous real-time navigation method, and can provide comprehensive navigation information, including position, velocity, attitude, attitude rate and time. In the paper the fundamental principles and time transformation of the XPNAV were analyzed, and then the Delta-correction XPNAV blending the vehicles' trajectory dynamics with the pulse time-of-arrival differences at nominal and estimated spacecraft locations within an Unscented Kalman Filter (UKF) was discussed with a background mission of Mars Pathfinder during the heliocentric transferring orbit. The XPNAV has an intractable problem of integer pulse phase cycle ambiguities similar to the GPS carrier phase navigation. This article innovatively proposed the non-ambiguity assumption approach based on an analysis of the search space array method to resolve pulse phase cycle ambiguities between the nominal position and estimated position of the spacecraft. The simulation results show that the search space array method are computationally intensive and require long processing time when the position errors are large, and the non-ambiguity assumption method can solve ambiguity problem quickly and reliably. It is deemed that autonomous real-time integrated navigation system of the XPNAV blending with DSN, celestial navigation, inertial navigation and so on will be the development direction of interplanetary flight navigation system in the future.

Celestial ephemerides in an expanding universe

NASA Astrophysics Data System (ADS)

Kopeikin, Sergei M.

2012-09-01

The post-Newtonian theory of motion of celestial bodies and propagation of light was instrumental in conducting the critical experimental tests of general relativity and in building the astronomical ephemerides of celestial bodies in the Solar System with unparalleled precision. The cornerstone of the theory is the postulate that the Solar System is gravitationally isolated from the rest of the Universe and the background spacetime is asymptotically flat. The present article extends this theoretical concept and formulates the principles of celestial dynamics of particles and light moving in the gravitational field of a localized astronomical system embedded to the expanding Friedmann-Lemaître-Robertson-Walker universe. We formulate the precise mathematical concept of the Newtonian limit of Einstein’s field equations in the conformally flat Friedmann-Lemaître-Robertson-Walker spacetime and analyze the geodesic motion of massive particles and light in this limit. We prove that by doing conformal spacetime transformations, one can reduce the equations of motion of particles and light to the classical form of the Newtonian theory. However, the time arguments in the equations of motion of particles and light differ from each other in terms being proportional to the Hubble constant H. This leads to the important conclusion that the equations of light propagation used currently by space navigation centers for fitting range and Doppler-tracking observations of celestial bodies are missing some terms of the cosmological origin that are proportional to the Hubble constant H. We also analyze the effect of the cosmological expansion on motion of electrons in atoms. We prove that the Hubble expansion does not affect the atomic frequencies and hence does not affect the atomic time scale used in the creation of astronomical ephemerides. We derive the cosmological correction to the light travel time equation and argue that its measurement opens an exciting opportunity to determine the local value of the Hubble constant H in the Solar System independently of cosmological observations.

Astronomical fire: Richard Carrington and the solar flare of 1859.

PubMed

Clark, Stuart

2007-09-01

An explosion on the Sun in 1859, serendipitously witnessed by amateur astronomer Richard Carrington, plunged telegraphic communications into chaos and bathed two thirds of the Earth's skies in aurorae. Explaining what happened to the Sun and how it could affect Earth, 93 million miles away, helped change the direction of astronomy. From being concerned principally with charting the stars to aid navigation, astronomers became increasingly concerned with what the celestial objects were, how they behaved and how they might affect life on Earth.

Application of the Deep Space Network (DSN) to the testing of general relativity

NASA Technical Reports Server (NTRS)

Anderson, J. D.; Levy, G. S.; Renzetti, N. A.

1986-01-01

The NASA Deep Space Network, a precision telecommunications and radio navigation facility, is described in detail. The first spacecraft relativity test with Mariner 6 and Mariner 7 at solar conjunction is discussed as well as more accurate tests using the Mariner 9 anchored to Mars. Consideration is also given to solar system tests of relativistic celestial mechanics and future prospects. It is noted that the NASA Mars Observer orbital mission is under development and is expected to reach Mars in 1991.

Chaos in navigation satellite orbits caused by the perturbed motion of the Moon

NASA Astrophysics Data System (ADS)

Rosengren, Aaron J.; Alessi, Elisa Maria; Rossi, Alessandro; Valsecchi, Giovanni B.

2015-06-01

Numerical simulations carried out over the past decade suggest that the orbits of the Global Navigation Satellite Systems are unstable, resulting in an apparent chaotic growth of the eccentricity. Here, we show that the irregular and haphazard character of these orbits reflects a similar irregularity in the orbits of many celestial bodies in our Solar system. We find that secular resonances, involving linear combinations of the frequencies of nodal and apsidal precession and the rate of regression of lunar nodes, occur in profusion so that the phase space is threaded by a devious stochastic web. As in all cases in the Solar system, chaos ensues where resonances overlap. These results may be significant for the analysis of disposal strategies for the four constellations in this precarious region of space.

Balloon platform for extended-life astronomy research

NASA Technical Reports Server (NTRS)

Ostwald, L. T.

1974-01-01

A configuration has been developed for a long-life balloon platform to carry pointing telescopes weighing as much as 80 pounds (36 kg) to point at selected celestial targets. A platform of this configuration weighs about 375 pounds (170 kg) gross and can be suspended from a high altitude super pressure balloon for a lifetime of several months. The balloon platform contains a solar array and storage batteries for electrical power, up and down link communications equipment, and navigational and attitude control systems for orienting the scientific instrument. A biaxial controller maintains the telescope attitude in response to look-angle data stored in an on-board computer memory which is updated periodically by ground command. Gimbal angles are computed by using location data derived by an on-board navigational receiver.

ATON (Autonomous Terrain-based Optical Navigation) for exploration missions: recent flight test results

NASA Astrophysics Data System (ADS)

Theil, S.; Ammann, N.; Andert, F.; Franz, T.; Krüger, H.; Lehner, H.; Lingenauber, M.; Lüdtke, D.; Maass, B.; Paproth, C.; Wohlfeil, J.

2018-03-01

Since 2010 the German Aerospace Center is working on the project Autonomous Terrain-based Optical Navigation (ATON). Its objective is the development of technologies which allow autonomous navigation of spacecraft in orbit around and during landing on celestial bodies like the Moon, planets, asteroids and comets. The project developed different image processing techniques and optical navigation methods as well as sensor data fusion. The setup—which is applicable to many exploration missions—consists of an inertial measurement unit, a laser altimeter, a star tracker and one or multiple navigation cameras. In the past years, several milestones have been achieved. It started with the setup of a simulation environment including the detailed simulation of camera images. This was continued by hardware-in-the-loop tests in the Testbed for Robotic Optical Navigation (TRON) where images were generated by real cameras in a simulated downscaled lunar landing scene. Data were recorded in helicopter flight tests and post-processed in real-time to increase maturity of the algorithms and to optimize the software. Recently, two more milestones have been achieved. In late 2016, the whole navigation system setup was flying on an unmanned helicopter while processing all sensor information onboard in real time. For the latest milestone the navigation system was tested in closed-loop on the unmanned helicopter. For that purpose the ATON navigation system provided the navigation state for the guidance and control of the unmanned helicopter replacing the GPS-based standard navigation system. The paper will give an introduction to the ATON project and its concept. The methods and algorithms of ATON are briefly described. The flight test results of the latest two milestones are presented and discussed.

Autonomous satellite navigation using starlight refraction angle measurements

NASA Astrophysics Data System (ADS)

Ning, Xiaolin; Wang, Longhua; Bai, Xinbei; Fang, Jiancheng

2013-05-01

An on-board autonomous navigation capability is required to reduce the operation costs and enhance the navigation performance of future satellites. Autonomous navigation by stellar refraction is a type of autonomous celestial navigation method that uses high-accuracy star sensors instead of Earth sensors to provide information regarding Earth's horizon. In previous studies, the refraction apparent height has typically been used for such navigation. However, the apparent height cannot be measured directly by a star sensor and can only be calculated by the refraction angle and an atmospheric refraction model. Therefore, additional errors are introduced by the uncertainty and nonlinearity of atmospheric refraction models, which result in reduced navigation accuracy and reliability. A new navigation method based on the direct measurement of the refraction angle is proposed to solve this problem. Techniques for the determination of the refraction angle are introduced, and a measurement model for the refraction angle is established. The method is tested and validated by simulations. When the starlight refraction height ranges from 20 to 50 km, a positioning accuracy of better than 100 m can be achieved for a low-Earth-orbit (LEO) satellite using the refraction angle, while the positioning accuracy of the traditional method using the apparent height is worse than 500 m under the same conditions. Furthermore, an analysis of the factors that affect navigation accuracy, including the measurement accuracy of the refraction angle, the number of visible refracted stars per orbit and the installation azimuth of star sensor, is presented. This method is highly recommended for small satellites in particular, as no additional hardware besides two star sensors is required.

Performance Enhancement of a USV INS/CNS/DVL Integration Navigation System Based on an Adaptive Information Sharing Factor Federated Filter

PubMed Central

Wang, Qiuying; Cui, Xufei; Li, Yibing; Ye, Fang

2017-01-01

To improve the ability of autonomous navigation for Unmanned Surface Vehicles (USVs), multi-sensor integrated navigation based on Inertial Navigation System (INS), Celestial Navigation System (CNS) and Doppler Velocity Log (DVL) is proposed. The CNS position and the DVL velocity are introduced as the reference information to correct the INS divergence error. The autonomy of the integrated system based on INS/CNS/DVL is much better compared with the integration based on INS/GNSS alone. However, the accuracy of DVL velocity and CNS position are decreased by the measurement noise of DVL and bad weather, respectively. Hence, the INS divergence error cannot be estimated and corrected by the reference information. To resolve the problem, the Adaptive Information Sharing Factor Federated Filter (AISFF) is introduced to fuse data. The information sharing factor of the Federated Filter is adaptively adjusted to maintaining multiple component solutions usable as back-ups, which can improve the reliability of overall system. The effectiveness of this approach is demonstrated by simulation and experiment, the results show that for the INS/CNS/DVL integrated system, when the DVL velocity accuracy is decreased and the CNS cannot work under bad weather conditions, the INS/CNS/DVL integrated system can operate stably based on the AISFF method. PMID:28165369

Performance Enhancement of a USV INS/CNS/DVL Integration Navigation System Based on an Adaptive Information Sharing Factor Federated Filter.

PubMed

Wang, Qiuying; Cui, Xufei; Li, Yibing; Ye, Fang

2017-02-03

To improve the ability of autonomous navigation for Unmanned Surface Vehicles (USVs), multi-sensor integrated navigation based on Inertial Navigation System (INS), Celestial Navigation System (CNS) and Doppler Velocity Log (DVL) is proposed. The CNS position and the DVL velocity are introduced as the reference information to correct the INS divergence error. The autonomy of the integrated system based on INS/CNS/DVL is much better compared with the integration based on INS/GNSS alone. However, the accuracy of DVL velocity and CNS position are decreased by the measurement noise of DVL and bad weather, respectively. Hence, the INS divergence error cannot be estimated and corrected by the reference information. To resolve the problem, the Adaptive Information Sharing Factor Federated Filter (AISFF) is introduced to fuse data. The information sharing factor of the Federated Filter is adaptively adjusted to maintaining multiple component solutions usable as back-ups, which can improve the reliability of overall system. The effectiveness of this approach is demonstrated by simulation and experiment, the results show that for the INS/CNS/DVL integrated system, when the DVL velocity accuracy is decreased and the CNS cannot work under bad weather conditions, the INS/CNS/DVL integrated system can operate stably based on the AISFF method.

Dawes Review 5: Australian Aboriginal Astronomy and Navigation

NASA Astrophysics Data System (ADS)

Norris, Ray P.

2016-08-01

The traditional cultures of Aboriginal Australians include a significant astronomical component, perpetuated through oral tradition, ceremony, and art. This astronomical knowledge includes a deep understanding of the motion of objects in the sky, which was used for practical purposes such as constructing calendars and for navigation. There is also evidence that traditional Aboriginal Australians made careful records and measurements of cyclical phenomena, recorded unexpected phenomena such as eclipses and meteorite impacts, and could determine the cardinal points to an accuracy of a few degrees. Putative explanations of celestial phenomena appear throughout the oral record, suggesting traditional Aboriginal Australians sought to understand the natural world around them, in the same way as modern scientists, but within their own cultural context. There is also a growing body of evidence for sophisticated navigational skills, including the use of astronomically based songlines. Songlines are effectively oral maps of the landscape, and are an efficient way of transmitting oral navigational skills in cultures that do not have a written language. The study of Aboriginal astronomy has had an impact extending beyond mere academic curiosity, facilitating cross-cultural understanding, demonstrating the intimate links between science and culture, and helping students to engage with science.

Vision and visual navigation in nocturnal insects.

PubMed

Warrant, Eric; Dacke, Marie

2011-01-01

With their highly sensitive visual systems, nocturnal insects have evolved a remarkable capacity to discriminate colors, orient themselves using faint celestial cues, fly unimpeded through a complicated habitat, and navigate to and from a nest using learned visual landmarks. Even though the compound eyes of nocturnal insects are significantly more sensitive to light than those of their closely related diurnal relatives, their photoreceptors absorb photons at very low rates in dim light, even during demanding nocturnal visual tasks. To explain this apparent paradox, it is hypothesized that the necessary bridge between retinal signaling and visual behavior is a neural strategy of spatial and temporal summation at a higher level in the visual system. Exactly where in the visual system this summation takes place, and the nature of the neural circuitry that is involved, is currently unknown but provides a promising avenue for future research.

Application of X-Ray Pulsar Navigation: A Characterization of the Earth Orbit Trade Space

NASA Technical Reports Server (NTRS)

Yu, Wayne

2016-01-01

The potential for pulsars as a navigation source has been studied since their discovery in 1967. X-ray pulsar navigation (XNAV) is a celestial navigation system that uses the consistent timing nature of x-ray photons from milli-second pulsars (MSP) to perform space navigation. By comparing the detected arrival of x-ray photons to a reference database of expected pulsar lightcurve timing models, one can infer a range and range rate measurement based on light time delay. Much of the challenge of XNAV comes from the faint signal, availability, and distant nature of pulsars. This is a study of potential pulsar XNAV measurements to measure extended Kalman filter (EKF) tracking performance with a wide trade space of bounded Earth orbits, using a simulation of existing x-ray detector space hardware. An example of an x-ray detector for XNAV is the NASA Station Explorer for X-ray Timing and Navigation (SEXTANT) mission, a technology demonstration of XNAV set to perform on the International Space Station (ISS) in late 2016early 2017. XNAV hardware implementation is driven by trajectory and environmental influences which add noise to the x-ray pulse signal. In a closed Earth orbit, the radiation environment can exponentially increase the signal noise from x-ray pulsar sources, decreasing the quality and frequency of measurements. The SEXTANT mission in particular improves on the signal to noise ratio by focusing an array of 56 x-ray silicon drift detectors at one pulsar target at a time. This reduces timing glitches and other timing noise contributions from ambient x-ray sources to within a 100 nanosecond resolution. This study also considers the SEXTANT scheduling challenges inherent in a single target observation. Finally, as the navigation sources are now relatively inertial targets, XNAV measurements are also subject to periods of occultation from various celestial bodies. This study focuses on the characterization of these drivers in closed Earth orbits and is not a tuning analysis of the EKF. The study shows that the closed Earth orbit for XNAV performance is reliant on the orbit semi-major axis and eccentricity as well as orbit inclination. These parameters are the primary drivers of pulsar measurement availability and significantly influence the natural spacecraft orbit dynamics. Sensitivity to initial orbit determination error growth due to the scarcity of XNAV measurements within an orbital period require appropriate timing of initial XNAV measurements. The orbit angles of argument of perigee and right ascension of the ascending node, alongside the other orbit parameters, complete the initial cadence of XNAV measurements. The performance of initial XNAV measurements then propagates throughout the experimental period. The study provides a basis to missions who wish to consider XNAV as a potential navigation source in a closed Earth orbit design. It provides a family of orbit trajectories as well as other modeling considerations needed to effectively evaluate if XNAV is an effective navigation source for a potential mission. As an EKF is sensitive to a linearized estimated state, this study has a direct benefit of providing effective XNAV measurements to maintain spacecraft tracking, independent of other navigation sources. In the particular use case of the SEXTANT mission, it also provides a novel scheduling algorithm which addresses the need to prioritize and manage pulsar observations for effective navigation.

Application of X-Ray Pulsar Navigation: A Characterization of the Earth Orbit Trade Space

NASA Technical Reports Server (NTRS)

Yu, Wayne Hong

2016-01-01

The potential for pulsars as a navigation source has been studied since their discovery in 1967. X-ray pulsar navigation (XNAV) is a celestial navigation system that uses the consistent timing nature of x-ray photons from millisecond pulsars (MSP) to perform space navigation. By comparing the detected arrival of x-ray photons to a reference database of expected pulsar light-curve timing models, one can infer a range and range rate measurement based on light time delay. Much of the challenge of XNAV comes from the faint signal, availability, and distant nature of pulsars. This is a study of potential pulsar XNAV measurements to measure extended Kalman filter (EKF) tracking performance with a wide trade space of bounded Earth orbits, using a simulation of existing x-ray detector space hardware. An example of an x-ray detector for XNAV is the NASA Station Explorer for X-ray Timing and Navigation (SEXTANT) mission, a technology demonstration of XNAV set to perform on the International Space Station (ISS) in late 2016early 2017. XNAV hardware implementation is driven by trajectory and environmental influences which add noise to the x-ray pulse signal. In a closed Earth orbit, the radiation environment can exponentially increase the signal noise from x-ray pulsar sources, decreasing the quality and frequency of measurements. The SEXTANT mission in particular improves on the signal to noise ratio by focusing an array of 56 x-ray silicon drift detectors at one pulsar target at a time. This reduces timing glitches and other timing noise contributions from ambient x-ray sources to within a 100 nanosecond resolution. This study also considers the SEXTANT scheduling challenges inherent in a single target observation. Finally, as the navigation sources are now relatively inertial targets, XNAV measurements are also subject to periods of occultation from various celestial bodies. This study focuses on the characterization of these drivers in closed Earth orbits and is not a tuning analysis of the EKF. The study shows that the closed Earth orbit for XNAV performance is reliant on the orbit semi-major axis and eccentricity as well as orbit inclination. These parameters are the primary drivers of pulsar measurement availability and significantly influence the natural spacecraft orbit dynamics. Sensitivity to initial orbit determination error growth due to the scarcity of XNAV measurements within an orbital period require appropriate timing of initial XNAV measurements. The orbit angles of argument of perigee and right ascension of the ascending node, alongside the other orbit parameters, complete the initial cadence of XNAV measurements. The performance of initial XNAV measurements then propagates throughout the experimental period. The study provides a basis to missions who wish to consider XNAV as a potential navigation source in a closed Earth orbit design. It provides a family of orbit trajectories as well as other modeling considerations needed to effectively evaluate if XNAV is an effective navigation source for a potential mission. As an EKF is sensitive to a linearized estimated state, this study has a direct benefit of providing effective XNAV measurements to maintain spacecraft tracking, independent of other navigation sources. In the particular use case of the SEXTANT mission, it also provides a novel scheduling algorithm which addresses the need to prioritize and manage pulsar observations for effective navigation.

A Novel Robust H∞ Filter Based on Krein Space Theory in the SINS/CNS Attitude Reference System.

PubMed

Yu, Fei; Lv, Chongyang; Dong, Qianhui

2016-03-18

Owing to their numerous merits, such as compact, autonomous and independence, the strapdown inertial navigation system (SINS) and celestial navigation system (CNS) can be used in marine applications. What is more, due to the complementary navigation information obtained from two different kinds of sensors, the accuracy of the SINS/CNS integrated navigation system can be enhanced availably. Thus, the SINS/CNS system is widely used in the marine navigation field. However, the CNS is easily interfered with by the surroundings, which will lead to the output being discontinuous. Thus, the uncertainty problem caused by the lost measurement will reduce the system accuracy. In this paper, a robust H∞ filter based on the Krein space theory is proposed. The Krein space theory is introduced firstly, and then, the linear state and observation models of the SINS/CNS integrated navigation system are established reasonably. By taking the uncertainty problem into account, in this paper, a new robust H∞ filter is proposed to improve the robustness of the integrated system. At last, this new robust filter based on the Krein space theory is estimated by numerical simulations and actual experiments. Additionally, the simulation and experiment results and analysis show that the attitude errors can be reduced by utilizing the proposed robust filter effectively when the measurements are missing discontinuous. Compared to the traditional Kalman filter (KF) method, the accuracy of the SINS/CNS integrated system is improved, verifying the robustness and the availability of the proposed robust H∞ filter.

Extending the ICRF to Higher Radio Frequencies

NASA Technical Reports Server (NTRS)

Jacobs, C. S.; Jones, D. L.; Lanyi, G. E.; Lowe, S. T.; Naudet, C. J.; Resch, G. M.; Steppe, J. A.; Zhang, L. D.; Ulvestad, J. S.; Taylor, G. B.

2002-01-01

The ICRF forms the basis for all astrometry including use as the inertial coordinate system for navigating deep space missions. This frame was defined using S/X-band observations over the past 20+ years. In January 2002, the VLBA approved our proposal for observing time to extend the ICRF to K-band (24 GHz) and Q-band (43 GHz). The first step will be observations at K- and Q-bands on a subset of ICRF sources. Eventually, K- and Q-band multi-epoch observations will be used to estimate positions, flux density and source structure for a large fraction of the current S/X-band ICRF source list. This work will benefit the radio astronomy community by extending the VLBA calibrator list at these bands. In the longer term, we would also like to extend the ICRF to Ka-band (32 GHz). A celestial reference frame will be needed at this frequency to support deep space navigation. A navigation demonstration is being considered for NASA's Mars 2005 mission. The initial K- and Q-band work will serve to identify candidate sources at Ka-band for use with that mission.

Experiment D005: Star occultation navigation

NASA Technical Reports Server (NTRS)

Silva, R. M.; Jorris, T. R.; Vallerie, E. M., III

1971-01-01

The usefulness of star occultation measurements for space navigation and the determination of a horizon density profile which could be used to update atmospheric models for horizon-based measurement systems were studied. The time of occultation of a known star by a celestial body, as seen by an orbiting observer, determines a cylinder of position, the axis of which is the line through the star and the body center, and the radius of which is equal to the occulting-body radius. The dimming percentage, with respect to the altitude of this grazing ray from the star to the observer, is a percentage altitude for occultation. That is, the star can be assumed to be occulted when it reaches a predetermined percentage of its unattenuated value. The procedure used was to measure this attenuation with respect to time to determine the usefulness of the measurements for autonomous space navigation. In this experiment, the crewmembers had to accomplish star acquisition, identification, calibration, and tracking. Instrumentation was required only for measurement of the relative intensity of the star as it set into the atmosphere.

Optimal multiguidance integration in insect navigation.

PubMed

Hoinville, Thierry; Wehner, Rüdiger

2018-03-13

In the last decades, desert ants have become model organisms for the study of insect navigation. In finding their way, they use two major navigational routines: path integration using a celestial compass and landmark guidance based on sets of panoramic views of the terrestrial environment. It has been claimed that this information would enable the insect to acquire and use a centralized cognitive map of its foraging terrain. Here, we present a decentralized architecture, in which the concurrently operating path integration and landmark guidance routines contribute optimally to the directions to be steered, with "optimal" meaning maximizing the certainty (reliability) of the combined information. At any one time during its journey, the animal computes a path integration (global) vector and landmark guidance (local) vector, in which the length of each vector is proportional to the certainty of the individual estimates. Hence, these vectors represent the limited knowledge that the navigator has at any one place about the direction of the goal. The sum of the global and local vectors indicates the navigator's optimal directional estimate. Wherever applied, this decentralized model architecture is sufficient to simulate the results of quite a number of diverse cue-conflict experiments, which have recently been performed in various behavioral contexts by different authors in both desert ants and honeybees. They include even those experiments that have deliberately been designed by former authors to strengthen the evidence for a metric cognitive map in bees.

On the trail of Vikings with polarized skylight: experimental study of the atmospheric optical prerequisites allowing polarimetric navigation by Viking seafarers.

PubMed

Horváth, Gábor; Barta, András; Pomozi, István; Suhai, Bence; Hegedüs, Ramón; Akesson, Susanne; Meyer-Rochow, Benno; Wehner, Rüdiger

2011-03-12

Between AD 900 and AD 1200 Vikings, being able to navigate skillfully across the open sea, were the dominant seafarers of the North Atlantic. When the Sun was shining, geographical north could be determined with a special sundial. However, how the Vikings could have navigated in cloudy or foggy situations, when the Sun's disc was unusable, is still not fully known. A hypothesis was formulated in 1967, which suggested that under foggy or cloudy conditions, Vikings might have been able to determine the azimuth direction of the Sun with the help of skylight polarization, just like some insects. This hypothesis has been widely accepted and is regularly cited by researchers, even though an experimental basis, so far, has not been forthcoming. According to this theory, the Vikings could have determined the direction of the skylight polarization with the help of an enigmatic birefringent crystal, functioning as a linearly polarizing filter. Such a crystal is referred to as 'sunstone' in one of the Viking's sagas, but its exact nature is unknown. Although accepted by many, the hypothesis of polarimetric navigation by Vikings also has numerous sceptics. In this paper, we summarize the results of our own celestial polarization measurements and psychophysical laboratory experiments, in which we studied the atmospheric optical prerequisites of possible sky-polarimetric navigation in Tunisia, Finland, Hungary and the high Arctic.

On the trail of Vikings with polarized skylight: experimental study of the atmospheric optical prerequisites allowing polarimetric navigation by Viking seafarers

PubMed Central

Horváth, Gábor; Barta, András; Pomozi, István; Suhai, Bence; Hegedüs, Ramón; Åkesson, Susanne; Meyer-Rochow, Benno; Wehner, Rüdiger

2011-01-01

Between AD 900 and AD 1200 Vikings, being able to navigate skillfully across the open sea, were the dominant seafarers of the North Atlantic. When the Sun was shining, geographical north could be determined with a special sundial. However, how the Vikings could have navigated in cloudy or foggy situations, when the Sun's disc was unusable, is still not fully known. A hypothesis was formulated in 1967, which suggested that under foggy or cloudy conditions, Vikings might have been able to determine the azimuth direction of the Sun with the help of skylight polarization, just like some insects. This hypothesis has been widely accepted and is regularly cited by researchers, even though an experimental basis, so far, has not been forthcoming. According to this theory, the Vikings could have determined the direction of the skylight polarization with the help of an enigmatic birefringent crystal, functioning as a linearly polarizing filter. Such a crystal is referred to as ‘sunstone’ in one of the Viking's sagas, but its exact nature is unknown. Although accepted by many, the hypothesis of polarimetric navigation by Vikings also has numerous sceptics. In this paper, we summarize the results of our own celestial polarization measurements and psychophysical laboratory experiments, in which we studied the atmospheric optical prerequisites of possible sky-polarimetric navigation in Tunisia, Finland, Hungary and the high Arctic. PMID:21282181

Autonomous orbital navigation using Kepler's equation

NASA Technical Reports Server (NTRS)

Boltz, F. W.

1974-01-01

A simple method of determining the six elements of elliptic satellite orbits has been developed for use aboard manned and unmanned spacecraft orbiting the earth, moon, or any planet. The system requires the use of a horizon sensor or other device for determining the local vertical, a precision clock or timing device, and Apollo-type navigation equipment including an inertial measurement unit (IMU), a digital computer, and a coupling data unit. The three elements defining the in-plane motion are obtained from simultaneous measurements of central angle traversed around the planet and elapsed flight time using a linearization of Kepler's equation about a reference orbit. It is shown how Kalman filter theory may also be used to determine the in-plane orbital elements. The three elements defining the orbit orientation are obtained from position angles in celestial coordinates derived from the IMU with the spacecraft vertically oriented after alignment of the IMU to a known inertial coordinate frame.

Infrasound and the avian navigational map

USGS Publications Warehouse

Hagstrum, J.T.

2001-01-01

Birds can accurately navigate over hundreds to thousands of kilometres, and use celestial and magnetic compass senses to orient their flight. How birds determine their location in order to select the correct homeward bearing (map sense) remains controversial, and has been attributed to their olfactory or magnetic senses. Pigeons can hear infrasound down to 0??05 Hz, and an acoustic avian map is proposed consisting of infrasonic cues radiated from steep-sided topographic features. The source of these infrasonic signals is microseisms continuously generated by interfering oceanic waves. Atmospheric processes affecting the infrasonic map cues can explain perplexing experimental results from pigeon releases. Moreover, four recent disrupted pigeon races in Europe and the north-eastern USA intersected infrasonic shock waves from the Concorde supersonic transport. Having an acoustic map might also allow clock-shifted birds to test their homeward progress and select between their magnetic and solar compasses.

Achieving Real-Time Tracking Mobile Wireless Sensors Using SE-KFA

NASA Astrophysics Data System (ADS)

Kadhim Hoomod, Haider, Dr.; Al-Chalabi, Sadeem Marouf M.

2018-05-01

Nowadays, Real-Time Achievement is very important in different fields, like: Auto transport control, some medical applications, celestial body tracking, controlling agent movements, detections and monitoring, etc. This can be tested by different kinds of detection devices, which named "sensors" as such as: infrared sensors, ultrasonic sensor, radars in general, laser light sensor, and so like. Ultrasonic Sensor is the most fundamental one and it has great impact and challenges comparing with others especially when navigating (as an agent). In this paper, concerning to the ultrasonic sensor, sensor(s) detecting and delimitation by themselves then navigate inside a limited area to estimating Real-Time using Speed Equation with Kalman Filter Algorithm as an intelligent estimation algorithm. Then trying to calculate the error comparing to the factual rate of tracking. This paper used Ultrasonic Sensor HC-SR04 with Arduino-UNO as Microcontroller.

The Determination of Earth Orientation by VLBI and GNSS: Principles and Results

NASA Astrophysics Data System (ADS)

Capitaine, Nicole

2017-10-01

The Earth Orientation Parameters (EOP) connect the International Terrestrial Reference System (ITRS) to the Geocentric Celestial Reference System (GCRS). These parameters, i.e., Universal Time, UT1, and pole coordinates in the ITRS and in the GCRS, describe the irregularities of the Earth's rotation. They are mainly determined by two modern astro-geodetic techniques, VLBI (Very Long Baseline Radio Interferometry) on extragalactic radio sources, which is used to realize and maintain the International Celestial Reference System (ICRS), and Global Navigation Satellite System (GNSS), especially GPS (Global Positioning System), which has an important contribution to the realization of the ITRS. The aim of this presentation is twofold: to present the modern bases for the consider- ation of Earth orientation and to discuss how the principles of VLBI and GPS give access to the measure of different components of the EOP variations, especially UT1. The accuracy that can be achieved is based on the improved concepts, definitions, and models that have been adopted by IAU/IUGG resolutions on reference systems and Earth's rotation, as well as on the refined strategy of the observations.

Orbital motion (3rd revised and enlarged edition)

NASA Astrophysics Data System (ADS)

Roy, A. E.

The fundamental principles of celestial mechanics are discussed in an introduction for students of astronomy, aerospace engineering, and geography. Chapters are devoted to the dynamic structure of the universe, coordinate and timekeeping systems, the reduction of observational data, the two-body problem, the many-body problem, general and special perturbations, and the stability and evolution of the solar system. Consideration is given to lunar theory, artificial satellites, rocket dynamics and transfer orbits, interplanetary and lunar trajectories, orbit determination and interplanetary navigation, binaries and other few-body systems, and many-body systems of stars. Diagrams, graphs, tables, and problems with solutions are provided.

Maplike representation of celestial E-vector orientations in the brain of an insect.

PubMed

Heinze, Stanley; Homberg, Uwe

2007-02-16

For many insects, the polarization pattern of the blue sky serves as a compass cue for spatial navigation. E-vector orientations are detected by photoreceptors in a dorsal rim area of the eye. Polarized-light signals from both eyes are finally integrated in the central complex, a brain area consisting of two subunits, the protocerebral bridge and the central body. Here we show that a topographic representation of zenithal E-vector orientations underlies the columnar organization of the protocerebral bridge in a locust. The maplike arrangement is highly suited to signal head orientation under the open sky.

KSC-98pc1087

NASA Image and Video Library

1998-09-17

KENNEDY SPACE CENTER, FLA. -- Workers in the Payload Hazardous Servicing Facility prepare Deep Space 1 for launch aboard a Boeing Delta 7326 rocket in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Most of its mission objectives will be completed within the first two months. A near-Earth asteroid, 1992 KD, has also been selected for a possible flyby

Deep Space 1 is prepared for launch

NASA Technical Reports Server (NTRS)

1998-01-01

Workers in the Payload Hazardous Servicing Facility prepare Deep Space 1 for launch aboard a Boeing Delta 7326 rocket in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Most of its mission objectives will be completed within the first two months. A near- Earth asteroid, 1992 KD, has also been selected for a possible flyby.

SEAC 2011 Stars and Stones: Voyages in Archaeoastronomy and Cultural Astronomy

NASA Astrophysics Data System (ADS)

Pimenta, F.; Ribeiro, N.; Silva, F.; Campion, N.; Joaquinito, A.; Tirapicos, L.

2015-05-01

Since Prehistory the sky has always been integrated as part of the cosmovision of human societies. The sky played a fundamental role not only in the orientation in space, time organization, ritual practices or celestial divination but also as an element of power. Migrations and voyages are intrinsic to humankind, they opened the routes for cultural diffusion and trade, but also for power dominance. Following these routes is also to follow cultural diversity and how human societies met or clashed. The sky and astronomical phenomena provided the tools for time reckoning, calendar organization and celestial navigation that supported those voyages. Astronomy gives us today the capacity to reproduce the sky, opening a window through which we can glimpse how those societies perceived, integrated and manipulated the sky into their world-views and their myths and, ultimately, into their social organization. A voyage is always a meeting of different worlds and eventually a process to accept diversity and thus we challenged the participants of the 19th meeting of the European Society for Astronomy in Culture to present their papers in the form of a voyage or an encounter for the following topics: - Techniques of celestial navigation and orientation of the past. Astronomical navigation and nautical instruments in the XIVth, XVth and XVIth centuries; - Expressions of astronomical knowledge in architecture and monuments, rock art, archaeology and landscape. People migration, a meeting between different cultures; - History of astronomy. An encounter between different conceptions; - Astronomy and the Jesuits. A meeting between different worlds; - Astronomy in antiquity. A meeting between different knowledge; - Ethno-astronomy, Cultural Astronomy and myths, voyages in space and in time through different cultures; - To where is Archaeoastronomy voyaging? A round table about Archaeoastronomy, Cultural Astronomy and Education. The 19th meeting of the European Society for Astronomy in Culture was held in Évora, Portugal, from September 19th to 23th, 2011, and was attended by 85 participants from 29 countries. A total number of 71 talks and 4 posters were presented. Among them 20 invited lectures given by Michael Rappenglüück, José Manuel Malhão Pereira, Jarita Holbrook, Giulio Magli, Nicholas Campion, J. Kim Malville, David Pankenier, Alejandro Martín López, Ivan Sprajc, Mariusz Ziólkowski, Marciano da Silva, Lionel Sims, Emilia Pasztor, Frank Prendergast, Fernando Pimenta, A. César González-Garcia, Henrique Leitão, Shi Yunli and Stanislaw Iwaniszewski and 3 public lectures given by Luísa Pereira, Juan Belmonte Avilés and Clive Ruggles. Most of the contributions were submitted for publication and went through a peer-review process. The present volume is the result of this process, arranged in the same thematic sections as the Conference was organised.

Moving in Dim Light: Behavioral and Visual Adaptations in Nocturnal Ants.

PubMed

Narendra, Ajay; Kamhi, J Frances; Ogawa, Yuri

2017-11-01

Visual navigation is a benchmark information processing task that can be used to identify the consequence of being active in dim-light environments. Visual navigational information that animals use during the day includes celestial cues such as the sun or the pattern of polarized skylight and terrestrial cues such as the entire panorama, canopy pattern, or significant salient features in the landscape. At night, some of these navigational cues are either unavailable or are significantly dimmer or less conspicuous than during the day. Even under these circumstances, animals navigate between locations of importance. Ants are a tractable system for studying navigation during day and night because the fine scale movement of individual animals can be recorded in high spatial and temporal detail. Ant species range from being strictly diurnal, crepuscular, and nocturnal. In addition, a number of species have the ability to change from a day- to a night-active lifestyle owing to environmental demands. Ants also offer an opportunity to identify the evolution of sensory structures for discrete temporal niches not only between species but also within a single species. Their unique caste system with an exclusive pedestrian mode of locomotion in workers and an exclusive life on the wing in males allows us to disentangle sensory adaptations that cater for different lifestyles. In this article, we review the visual navigational abilities of nocturnal ants and identify the optical and physiological adaptations they have evolved for being efficient visual navigators in dim-light. © The Author 2017. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

A Novel Robust H∞ Filter Based on Krein Space Theory in the SINS/CNS Attitude Reference System

PubMed Central

Yu, Fei; Lv, Chongyang; Dong, Qianhui

2016-01-01

Owing to their numerous merits, such as compact, autonomous and independence, the strapdown inertial navigation system (SINS) and celestial navigation system (CNS) can be used in marine applications. What is more, due to the complementary navigation information obtained from two different kinds of sensors, the accuracy of the SINS/CNS integrated navigation system can be enhanced availably. Thus, the SINS/CNS system is widely used in the marine navigation field. However, the CNS is easily interfered with by the surroundings, which will lead to the output being discontinuous. Thus, the uncertainty problem caused by the lost measurement will reduce the system accuracy. In this paper, a robust H∞ filter based on the Krein space theory is proposed. The Krein space theory is introduced firstly, and then, the linear state and observation models of the SINS/CNS integrated navigation system are established reasonably. By taking the uncertainty problem into account, in this paper, a new robust H∞ filter is proposed to improve the robustness of the integrated system. At last, this new robust filter based on the Krein space theory is estimated by numerical simulations and actual experiments. Additionally, the simulation and experiment results and analysis show that the attitude errors can be reduced by utilizing the proposed robust filter effectively when the measurements are missing discontinuous. Compared to the traditional Kalman filter (KF) method, the accuracy of the SINS/CNS integrated system is improved, verifying the robustness and the availability of the proposed robust H∞ filter. PMID:26999153

Study on UKF based federal integrated navigation for high dynamic aviation

NASA Astrophysics Data System (ADS)

Zhao, Gang; Shao, Wei; Chen, Kai; Yan, Jie

2011-08-01

High dynamic aircraft is a very attractive new generation vehicles, in which provides near space aviation with large flight envelope both speed and altitude, for example the hypersonic vehicles. The complex flight environments for high dynamic vehicles require high accuracy and stability navigation scheme. Since the conventional Strapdown Inertial Navigation System (SINS) and Global Position System (GPS) federal integrated scheme based on EKF (Extended Kalman Filter) is invalidation in GPS single blackout situation because of high speed flight, a new high precision and stability integrated navigation approach is presented in this paper, in which the SINS, GPS and Celestial Navigation System (CNS) is combined as a federal information fusion configuration based on nonlinear Unscented Kalman Filter (UKF) algorithm. Firstly, the new integrated system state error is modeled. According to this error model, the SINS system is used as the navigation solution mathematic platform. The SINS combine with GPS constitute one error estimation filter subsystem based on UKF to obtain local optimal estimation, and the SINS combine with CNS constitute another error estimation subsystem. A non-reset federated configuration filter based on partial information is proposed to fuse two local optimal estimations to get global optimal error estimation, and the global optimal estimation is used to correct the SINS navigation solution. The χ 2 fault detection method is used to detect the subsystem fault, and the fault subsystem is isolation through fault interval to protect system away from the divergence. The integrated system takes advantages of SINS, GPS and CNS to an immense improvement for high accuracy and reliably high dynamic navigation application. Simulation result shows that federated fusion of using GPS and CNS to revise SINS solution is reasonable and availably with good estimation performance, which are satisfied with the demands of high dynamic flight navigation. The UKF is superior than EKF based integrated scheme, in which has smaller estimation error and quickly convergence rate.

Autonomous Navigation Using Celestial Objects

NASA Technical Reports Server (NTRS)

Folta, David; Gramling, Cheryl; Leung, Dominic; Belur, Sheela; Long, Anne

1999-01-01

In the twenty-first century, National Aeronautics and Space Administration (NASA) Enterprises envision frequent low-cost missions to explore the solar system, observe the universe, and study our planet. Satellite autonomy is a key technology required to reduce satellite operating costs. The Guidance, Navigation, and Control Center (GNCC) at the Goddard Space Flight Center (GSFC) currently sponsors several initiatives associated with the development of advanced spacecraft systems to provide autonomous navigation and control. Autonomous navigation has the potential both to increase spacecraft navigation system performance and to reduce total mission cost. By eliminating the need for routine ground-based orbit determination and special tracking services, autonomous navigation can streamline spacecraft ground systems. Autonomous navigation products can be included in the science telemetry and forwarded directly to the scientific investigators. In addition, autonomous navigation products are available onboard to enable other autonomous capabilities, such as attitude control, maneuver planning and orbit control, and communications signal acquisition. Autonomous navigation is required to support advanced mission concepts such as satellite formation flying. GNCC has successfully developed high-accuracy autonomous navigation systems for near-Earth spacecraft using NASA's space and ground communications systems and the Global Positioning System (GPS). Recently, GNCC has expanded its autonomous navigation initiative to include satellite orbits that are beyond the regime in which use of GPS is possible. Currently, GNCC is assessing the feasibility of using standard spacecraft attitude sensors and communication components to provide autonomous navigation for missions including: libration point, gravity assist, high-Earth, and interplanetary orbits. The concept being evaluated uses a combination of star, Sun, and Earth sensor measurements along with forward-link Doppler measurements from the command link carrier to autonomously estimate the spacecraft's orbit and reference oscillator's frequency. To support autonomous attitude determination and control and maneuver planning and control, the orbit determination accuracy should be on the order of kilometers in position and centimeters per second in velocity. A less accurate solution (one hundred kilometers in position) could be used for acquisition purposes for command and science downloads. This paper provides performance results for both libration point orbiting and high Earth orbiting satellites as a function of sensor measurement accuracy, measurement types, measurement frequency, initial state errors, and dynamic modeling errors.

Transmission of linearly polarized light in seawater: implications for polarization signaling.

PubMed

Shashar, Nadav; Sabbah, Shai; Cronin, Thomas W

2004-09-01

Partially linearly polarized light is abundant in the oceans. The natural light field is partially polarized throughout the photic range, and some objects and animals produce a polarization pattern of their own. Many polarization-sensitive marine animals take advantage of the polarization information, using it for tasks ranging from navigation and finding food to communication. In such tasks, the distance to which the polarization information propagates is of great importance. Using newly designed polarization sensors, we measured the changes in linear polarization underwater as a function of distance from a standard target. In the relatively clear waters surrounding coral reefs, partial (%) polarization decreased exponentially as a function of distance from the target, resulting in a 50% reduction of partial polarization at a distance of 1.25-3 m, depending on water quality. Based on these measurements, we predict that polarization sensitivity will be most useful for short-range (in the order of meters) visual tasks in water and less so for detecting objects, signals, or structures from far away. Navigation and body orientation based on the celestial polarization pattern are predicted to be limited to shallow waters as well, while navigation based on the solar position is possible through a deeper range.

Estimating Uncertainties of Ship Course and Speed in Early Navigations using ICOADS3.0

NASA Astrophysics Data System (ADS)

Chan, D.; Huybers, P. J.

2017-12-01

Information on ship position and its uncertainty is potentially important for mapping out climatologists and changes in SSTs. Using the 2-hourly ship reports from the International Comprehensive Ocean Atmosphere Dataset 3.0 (ICOADS 3.0), we estimate the uncertainties of ship course, ship speed, and latitude/longitude corrections during 1870-1900. After reviewing the techniques used in early navigations, we build forward navigation model that uses dead reckoning technique, celestial latitude corrections, and chronometer longitude corrections. The modeled ship tracks exhibit jumps in longitude and latitude, when a position correction is applied. These jumps are also seen in ICOADS3.0 observations. In this model, position error at the end of each day increases following a 2D random walk; the latitudinal/longitude errors are reset when a latitude/longitude correction is applied.We fit the variance of the magnitude of latitude/longitude corrections in the observation against model outputs, and estimate that the standard deviation of uncertainty is 5.5 degree for ship course, 32% for ship speed, 22km for latitude correction, and 27km for longitude correction. The estimates here are informative priors for Bayesian methods that quantify position errors of individual tracks.

Local Observability Analysis of Star Sensor Installation Errors in a SINS/CNS Integration System for Near-Earth Flight Vehicles.

PubMed

Yang, Yanqiang; Zhang, Chunxi; Lu, Jiazhen

2017-01-16

Strapdown inertial navigation system/celestial navigation system (SINS/CNS) integrated navigation is a fully autonomous and high precision method, which has been widely used to improve the hitting accuracy and quick reaction capability of near-Earth flight vehicles. The installation errors between SINS and star sensors have been one of the main factors that restrict the actual accuracy of SINS/CNS. In this paper, an integration algorithm based on the star vector observations is derived considering the star sensor installation error. Then, the star sensor installation error is accurately estimated based on Kalman Filtering (KF). Meanwhile, a local observability analysis is performed on the rank of observability matrix obtained via linearization observation equation, and the observable conditions are presented and validated. The number of star vectors should be greater than or equal to 2, and the times of posture adjustment also should be greater than or equal to 2. Simulations indicate that the star sensor installation error could be readily observable based on the maneuvering condition; moreover, the attitude errors of SINS are less than 7 arc-seconds. This analysis method and conclusion are useful in the ballistic trajectory design of near-Earth flight vehicles.

Honeybees as a model for the study of visually guided flight, navigation, and biologically inspired robotics.

PubMed

Srinivasan, Mandyam V

2011-04-01

Research over the past century has revealed the impressive capacities of the honeybee, Apis mellifera, in relation to visual perception, flight guidance, navigation, and learning and memory. These observations, coupled with the relative ease with which these creatures can be trained, and the relative simplicity of their nervous systems, have made honeybees an attractive model in which to pursue general principles of sensorimotor function in a variety of contexts, many of which pertain not just to honeybees, but several other animal species, including humans. This review begins by describing the principles of visual guidance that underlie perception of the world in three dimensions, obstacle avoidance, control of flight speed, and orchestrating smooth landings. We then consider how navigation over long distances is accomplished, with particular reference to how bees use information from the celestial compass to determine their flight bearing, and information from the movement of the environment in their eyes to gauge how far they have flown. Finally, we illustrate how some of the principles gleaned from these studies are now being used to design novel, biologically inspired algorithms for the guidance of unmanned aerial vehicles.

Celestial polarization patterns sufficient for Viking navigation with the naked eye: detectability of Haidinger's brushes on the sky versus meteorological conditions

NASA Astrophysics Data System (ADS)

Horváth, Gábor; Takács, Péter; Kretzer, Balázs; Szilasi, Szilvia; Száz, Dénes; Farkas, Alexandra; Barta, András

2017-02-01

If a human looks at the clear blue sky from which light with high enough degree of polarization d originates, an 8-shaped bowtie-like figure, the yellow Haidinger's brush can be perceived, the long axis of which points towards the sun. A band of high d arcs across the sky at 90° from the sun. A person can pick two points on that band, observe the yellow brushes and triangulate the position of the sun based on the orientation of the two observed brushes. This method has been suggested to have been used on the open sea by Viking navigators to determine the position of the invisible sun occluded by cloud or fog. Furthermore, Haidinger's brushes can also be used to locate the sun when it is below the horizon or occluded by objects on the horizon. To determine the position of the sun using the celestial polarization pattern, the d of the portion of the sky used must be greater than the viewer's degree of polarization threshold d* for perception of Haidinger's brushes. We studied under which sky conditions the prerequisite d > d* is satisfied. Using full-sky imaging polarimetry, we measured the d-pattern of skylight in the blue (450 nm) spectral range for 1296 different meteorological conditions with different solar elevation angles θ and per cent cloud cover ρ. From the measured d-patterns of a given sky we determined the proportion P of the sky for which d > d*. We obtained that P is the largest at low solar elevations θ ≈ 0° and under totally or nearly clear skies with cloud coverage ρ = 0%, when the sun's position is already easily determined. If the sun is below the horizon (-5° ≤ θ < 0°) during twilight, P = 76.17 ± 4.18% for dmin∗=23 % under clear sky conditions. Consequently, the sky-polarimetric Viking navigation based on Haidinger's brushes is most useful after sunset and prior to sunrise, when the sun is not visible and large sky regions are bright, clear and polarized enough for perception of Haidinger's brushes.

Multi-Sensor Fusion with Interaction Multiple Model and Chi-Square Test Tolerant Filter.

PubMed

Yang, Chun; Mohammadi, Arash; Chen, Qing-Wei

2016-11-02

Motivated by the key importance of multi-sensor information fusion algorithms in the state-of-the-art integrated navigation systems due to recent advancements in sensor technologies, telecommunication, and navigation systems, the paper proposes an improved and innovative fault-tolerant fusion framework. An integrated navigation system is considered consisting of four sensory sub-systems, i.e., Strap-down Inertial Navigation System (SINS), Global Navigation System (GPS), the Bei-Dou2 (BD2) and Celestial Navigation System (CNS) navigation sensors. In such multi-sensor applications, on the one hand, the design of an efficient fusion methodology is extremely constrained specially when no information regarding the system's error characteristics is available. On the other hand, the development of an accurate fault detection and integrity monitoring solution is both challenging and critical. The paper addresses the sensitivity issues of conventional fault detection solutions and the unavailability of a precisely known system model by jointly designing fault detection and information fusion algorithms. In particular, by using ideas from Interacting Multiple Model (IMM) filters, the uncertainty of the system will be adjusted adaptively by model probabilities and using the proposed fuzzy-based fusion framework. The paper also addresses the problem of using corrupted measurements for fault detection purposes by designing a two state propagator chi-square test jointly with the fusion algorithm. Two IMM predictors, running in parallel, are used and alternatively reactivated based on the received information form the fusion filter to increase the reliability and accuracy of the proposed detection solution. With the combination of the IMM and the proposed fusion method, we increase the failure sensitivity of the detection system and, thereby, significantly increase the overall reliability and accuracy of the integrated navigation system. Simulation results indicate that the proposed fault tolerant fusion framework provides superior performance over its traditional counterparts.

Multi-Sensor Fusion with Interaction Multiple Model and Chi-Square Test Tolerant Filter

PubMed Central

Yang, Chun; Mohammadi, Arash; Chen, Qing-Wei

2016-01-01

Motivated by the key importance of multi-sensor information fusion algorithms in the state-of-the-art integrated navigation systems due to recent advancements in sensor technologies, telecommunication, and navigation systems, the paper proposes an improved and innovative fault-tolerant fusion framework. An integrated navigation system is considered consisting of four sensory sub-systems, i.e., Strap-down Inertial Navigation System (SINS), Global Navigation System (GPS), the Bei-Dou2 (BD2) and Celestial Navigation System (CNS) navigation sensors. In such multi-sensor applications, on the one hand, the design of an efficient fusion methodology is extremely constrained specially when no information regarding the system’s error characteristics is available. On the other hand, the development of an accurate fault detection and integrity monitoring solution is both challenging and critical. The paper addresses the sensitivity issues of conventional fault detection solutions and the unavailability of a precisely known system model by jointly designing fault detection and information fusion algorithms. In particular, by using ideas from Interacting Multiple Model (IMM) filters, the uncertainty of the system will be adjusted adaptively by model probabilities and using the proposed fuzzy-based fusion framework. The paper also addresses the problem of using corrupted measurements for fault detection purposes by designing a two state propagator chi-square test jointly with the fusion algorithm. Two IMM predictors, running in parallel, are used and alternatively reactivated based on the received information form the fusion filter to increase the reliability and accuracy of the proposed detection solution. With the combination of the IMM and the proposed fusion method, we increase the failure sensitivity of the detection system and, thereby, significantly increase the overall reliability and accuracy of the integrated navigation system. Simulation results indicate that the proposed fault tolerant fusion framework provides superior performance over its traditional counterparts. PMID:27827832

THE CELESTIAL REFERENCE FRAME AT 24 AND 43 GHz. I. ASTROMETRY

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

Lanyi, G. E.; Jacobs, C. S.; Naudet, C. J.

2010-05-15

We present astrometric results for compact extragalactic objects observed with the Very Long Baseline Array at radio frequencies of 24 and 43 GHz. Data were obtained from ten 24 hr observing sessions made over a five-year period. These observations were motivated by the need to extend the International Celestial Reference Frame (ICRF) to higher radio frequencies to enable improved deep space navigation after 2016 and to improve state-of-the-art astrometry. Source coordinates for 268 sources were estimated at 24 GHz and for 131 sources at 43 GHz. The median formal uncertainties of right ascension and declination at 24 GHz are 0.08more » and 0.15 mas, respectively. Median formal uncertainties at 43 GHz are 0.20 and 0.35 mas, respectively. Weighted root-mean-square differences between the 24 and 43 GHz positions and astrometric positions based on simultaneous 2.3 and 8.4 GHz Very Long Baseline Interferometry observations, such as the ICRF, are less than about 0.3 mas in both coordinates. With observations over five years we have achieved a precision at 24 GHz approaching that of the ICRF but unaccounted systematic errors limit the overall accuracy of the catalogs.« less

Haze, clouds and limited sky visibility: polarotactic orientation of crickets under difficult stimulus conditions.

PubMed

Henze, Miriam J; Labhart, Thomas

2007-09-01

Field crickets (Gryllus campestris L.) are able to detect the orientation of the electric vector (e-vector) of linearly polarized light. They presumably use this sense to exploit the celestial polarization pattern for course control or navigation. Polarization vision in crickets can be tested by eliciting a spontaneous polarotactic response. Previously, wide and 100% polarized stimuli were employed to induce this behavior. However, field crickets live on meadows where the observation of the sky is strongly limited by surrounding vegetation. Moreover, degrees of polarization (d) in the natural sky are much lower than 100%. We have therefore investigated thresholds for the behavioral response to polarized light under conditions mimicking those experienced by the insects in the field. We show that crickets are able to rely on polarized stimuli of just 1 degrees diameter. We also provide evidence that they exploit polarization down to an (average) polarization level of less than 7%, irrespective of whether the stimulus is homogeneous, such as under haze, or patched, such as a sky spotted by clouds. Our data demonstrate that crickets can rely on skylight polarization even under unfavorable celestial conditions, emphasizing the significance of polarized skylight orientation for insects.

Interactions of the polarization and the sun compass in path integration of desert ants.

PubMed

Lebhardt, Fleur; Ronacher, Bernhard

2014-08-01

Desert ants, Cataglyphis fortis, perform large-scale foraging trips in their featureless habitat using path integration as their main navigation tool. To determine their walking direction they use primarily celestial cues, the sky's polarization pattern and the sun position. To examine the relative importance of these two celestial cues, we performed cue conflict experiments. We manipulated the polarization pattern experienced by the ants during their outbound foraging excursions, reducing it to a single electric field (e-)vector direction with a linear polarization filter. The simultaneous view of the sun created situations in which the directional information of the sun and the polarization compass disagreed. The heading directions of the homebound runs recorded on a test field with full view of the natural sky demonstrate that none of both compasses completely dominated over the other. Rather the ants seemed to compute an intermediate homing direction to which both compass systems contributed roughly equally. Direct sunlight and polarized light are detected in different regions of the ant's compound eye, suggesting two separate pathways for obtaining directional information. In the experimental paradigm applied here, these two pathways seem to feed into the path integrator with similar weights.

Deep Space 1 is prepared for launch

NASA Technical Reports Server (NTRS)

1998-01-01

Workers in the Payload Hazardous Servicing Facility test equipment on Deep Space 1 to prepare it for launch aboard a Boeing Delta 7326 rocket in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Most of its mission objectives will be completed within the first two months. A near-Earth asteroid, 1992 KD, has also been selected for a possible flyby.

Some Aspects of Artificial Bodies Stabilization and Orientation

NASA Astrophysics Data System (ADS)

Samardzija, B.; Segan, S.

2012-12-01

To increase energy resources, and thus the overall possibility of modern cosmic aircrafts, power supply was expanded by adding the (moving) wing area and antenna with complex orientation and design. It is clear that all of this, when there is a need to conduct a very accurate account of orbital elements of satellites, is a nightmare for the experts and scientists. In this paper we will give special attention to the system of stabilization and orientation of satellites, as well as to the importance of gyroscopic effects and the navigation systems of the artificial celestial bodies. Development of modified practical solutions based on knowledge and experience with gyroscopic effects is immeasurable.

Deep Space 1 is prepared for launch

NASA Technical Reports Server (NTRS)

1998-01-01

Workers in the Payload Hazardous Servicing Facility check equipment on Deep Space 1 to prepare it for launch aboard a Boeing Delta 7326 rocket in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Most of its mission objectives will be completed within the first two months. A near-Earth asteroid, 1992 KD, has also been selected for a possible flyby.

Deep Space 1 is prepared for launch

NASA Technical Reports Server (NTRS)

1998-01-01

Workers in the Payload Hazardous Servicing Facility remove a solar panel from Deep Space 1 as part of the preparations for launch aboard a Boeing Delta 7326 rocket in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Most of its mission objectives will be completed within the first two months. A near- Earth asteroid, 1992 KD, has also been selected for a possible flyby.

Deep Space 1 is prepared for launch

NASA Technical Reports Server (NTRS)

1998-01-01

Workers in the Payload Hazardous Servicing Facility check out Deep Space 1 to prepare it for launch aboard a Boeing Delta 7326 rocket in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Most of its mission objectives will be completed within the first two months. A near-Earth asteroid, 1992 KD, has also been selected for a possible flyby.

KSC-98pc1088

NASA Image and Video Library

1998-09-17

KENNEDY SPACE CENTER, FLA. -- Workers in the Payload Hazardous Servicing Facility remove a solar panel from Deep Space 1 as part of the preparations for launch aboard a Boeing Delta 7326 rocket in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Most of its mission objectives will be completed within the first two months. A near-Earth asteroid, 1992 KD, has also been selected for a possible flyby

KSC-98pc1090

NASA Image and Video Library

1998-09-17

KENNEDY SPACE CENTER, FLA. -- Workers in the Payload Hazardous Servicing Facility check equipment on Deep Space 1 to prepare it for launch aboard a Boeing Delta 7326 rocket in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Most of its mission objectives will be completed within the first two months. A near-Earth asteroid, 1992 KD, has also been selected for a possible flyby

KSC-98pc1089

NASA Image and Video Library

1998-09-17

KENNEDY SPACE CENTER, FLA. -- Workers in the Payload Hazardous Servicing Facility check out Deep Space 1 to prepare it for launch aboard a Boeing Delta 7326 rocket in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Most of its mission objectives will be completed within the first two months. A near-Earth asteroid, 1992 KD, has also been selected for a possible flyby

KSC-98pc1091

NASA Image and Video Library

1998-09-17

KENNEDY SPACE CENTER, FLA. -- Workers in the Payload Hazardous Servicing Facility test equipment on Deep Space 1 to prepare it for launch aboard a Boeing Delta 7326 rocket in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Most of its mission objectives will be completed within the first two months. A near-Earth asteroid, 1992 KD, has also been selected for a possible flyby

Navigation of the space VLBI mission-HALCA

NASA Technical Reports Server (NTRS)

You, Tung Han; Ellis, Jordan; Mottinger, Neil

1998-01-01

In February 1997, the Japanese Space Agency ISAS launched the first space VLBI satellite, HALCA, with an 8 meter diameter wire mesh antenna and radio astronomy receivers capable of observing at 1.6, 4.8, and 22 Ghz. In a 560 by 21000 km orbit with a 6 hour period and 31 degree inclination, it observes celestial radio sources in conjunction with a world wide network of ground radio telescopes as part of an international collaborative effort which includes facilities in Japan, the U.S., Canada, Australia, and Europe. JPL is providing tracking and navigation support using a dedicated subnet of 11 meter antennas as well as co-observations using the DSN 70 meter antennas. This paper describes the spacecraft dynamics model and orbit determination strategies developed to meet the stringent trajectory accuracy requirements for generating predictions for the transfer of a stable uplink frequency to the spacecraft and for determining reconstructed orbits for delivery to the NRAO VLBI correlator and the international VLBI science community.

Honeybees use the skyline in orientation.

PubMed

Towne, William F; Ritrovato, Antoinette E; Esposto, Antonina; Brown, Duncan F

2017-07-01

In view-based navigation, animals acquire views of the landscape from various locations and then compare the learned views with current views in order to orient in certain directions or move toward certain destinations. One landscape feature of great potential usefulness in view-based navigation is the skyline, the silhouette of terrestrial objects against the sky, as it is distant, relatively stable and easy to detect. The skyline has been shown to be important in the view-based navigation of ants, but no flying insect has yet been shown definitively to use the skyline in this way. Here, we show that honeybees do indeed orient using the skyline. A feeder was surrounded with an artificial replica of the natural skyline there, and the bees' departures toward the nest were recorded from above with a video camera under overcast skies (to eliminate celestial cues). When the artificial skyline was rotated, the bees' departures were rotated correspondingly, showing that the bees oriented by the artificial skyline alone. We discuss these findings in the context of the likely importance of the skyline in long-range homing in bees, the likely importance of altitude in using the skyline, the likely role of ultraviolet light in detecting the skyline, and what we know about the bees' ability to resolve skyline features. © 2017. Published by The Company of Biologists Ltd.

Local Observability Analysis of Star Sensor Installation Errors in a SINS/CNS Integration System for Near-Earth Flight Vehicles

PubMed Central

Yang, Yanqiang; Zhang, Chunxi; Lu, Jiazhen

2017-01-01

Strapdown inertial navigation system/celestial navigation system (SINS/CNS) integrated navigation is a fully autonomous and high precision method, which has been widely used to improve the hitting accuracy and quick reaction capability of near-Earth flight vehicles. The installation errors between SINS and star sensors have been one of the main factors that restrict the actual accuracy of SINS/CNS. In this paper, an integration algorithm based on the star vector observations is derived considering the star sensor installation error. Then, the star sensor installation error is accurately estimated based on Kalman Filtering (KF). Meanwhile, a local observability analysis is performed on the rank of observability matrix obtained via linearization observation equation, and the observable conditions are presented and validated. The number of star vectors should be greater than or equal to 2, and the times of posture adjustment also should be greater than or equal to 2. Simulations indicate that the star sensor installation error could be readily observable based on the maneuvering condition; moreover, the attitude errors of SINS are less than 7 arc-seconds. This analysis method and conclusion are useful in the ballistic trajectory design of near-Earth flight vehicles. PMID:28275211

Method for deploying multiple spacecraft

NASA Technical Reports Server (NTRS)

Sharer, Peter J. (Inventor)

2007-01-01

A method for deploying multiple spacecraft is disclosed. The method can be used in a situation where a first celestial body is being orbited by a second celestial body. The spacecraft are loaded onto a single spaceship that contains the multiple spacecraft and the spacecraft is launched from the second celestial body towards a third celestial body. The spacecraft are separated from each other while in route to the third celestial body. Each of the spacecraft is then subjected to the gravitational field of the third celestial body and each of the spacecraft assumes a different, independent orbit about the first celestial body. In those situations where the spacecraft are launched from Earth, the Sun can act as the first celestial body, the Earth can act as the second celestial body and the Moon can act as the third celestial body.

The Migration Matrix: Marine Vertebrate Movements in Magnetic Coordinate Space

NASA Astrophysics Data System (ADS)

Horton, T. W.; Holdaway, R. N.; Clapham, P. J.; Zerbini, A. N.; Andriolo, A.; Hays, G. C.; Egevang, C.; Domeier, M. L.; Lucas, N.

2011-12-01

Determining how vertebrates navigate during their long-distance migrations remains one of the most enduring and fundamental challenges of behavioral ecology. It is widely accepted that spatial orientation relative to a reference datum is a fundamental requirement of long-distance return migration between seasonal habitats, and a variety of viable positional and directional orientation cues, including the sun, stars, and magnetic field, have been documented experimentally. However, a fundamental question remains unanswered: Are empirically observed migratory movements compatible with modern theoretical frameworks of spatial orientation? To address this question, we analysed leatherback turtle (Dermochelys coriacea), arctic tern (Sterna paradisaea), humpback whale (Megaptera novaeangliae), and great white shark (Carcharodon carcharias) track maps, frequency distribution diagrams and time-series plots of animal locations in spherical magnetic coordinate space. Our analyses indicates that, although individual migration tracks are spatially and temporally distinct, vertebrate movements are non-randomly distributed in all three spherical magnetic coordinates (i.e. intensity, inclination, and declination). Stop-over locations, migratory destinations, and re-orientation points occur at similar magnetic coordinate locations, relative to tagging areas, in all four species, suggesting that a common system of magnetic orientation likely informs the navigational behaviors of these phylogenetically diverse taxa. Although our analyses demonstrate that the experiment-derived 'magnetic map' goal orientation theoretical framework of animal navigation is compatible with remotely-sensed migration track data, they also indicate that magnetic information is complemented by spatially and temporally contingent celestial stimuli during navigation.

Deep Space 1 fairing arrives at pad 17A for launch

NASA Technical Reports Server (NTRS)

1998-01-01

The fairing for Deep Space 1 nears the top of the Mobile Service Tower before being attached to the Boeing Delta 7326 rocket that will launch on Oct. 15, 1998. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

Lethocerus americanus, the "toe biter".

PubMed

Huntley, A

1998-10-01

Lethocerus americanus is a large water bug commonly found in ponds and slowly moving fresh water. Also known as the "toe biter" for its encounters with swimmers, it has the reputation of inflicting painful bites when carelessly handled. It normally feeds on other pond life: insects, tadpoles, salamander, small fish, and snails. These large tan or brown bugs may leave their habitat at night in search of mates or another pond. It is thought that the relative nearness of bright lights for a creature that evolved using celestial navigation, results in disorientation, spiral flight paths, and eventual death from exhaustion. This would account for the occasional find of several dead giant water bugs underneath street lamps.

Deep Space 1 arrives at KSC and processing begins in the PHSF

NASA Technical Reports Server (NTRS)

1998-01-01

NASA's Deep Space 1 spacecraft waits in the Payload Hazardous Servicing Facility for prelaunch processing. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

KSC-98pc1150

NASA Image and Video Library

1998-09-22

KENNEDY SPACE CENTER, FLA. -- Workers in the Payload Hazardous Servicing Facility (PHSF) attach a solar panel to Deep Space 1. The payload is scheduled to fly on the Boeing Delta 7326 rocket to be launched in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1050

NASA Image and Video Library

1998-09-11

The first stage of Boeing's Delta 7326 rocket, which will be used to launch the Deep Space 1 spacecraft, arrives at Pad 17A at Cape Canaveral Air Station. Targeted for launch on Oct. 15, 1998, this first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1051

NASA Image and Video Library

1998-09-11

The first stage of Boeing's Delta 7326 rocket, which will be used to launch the Deep Space 1 spacecraft, arrives at Pad 17A at Cape Canaveral Air Station. Targeted for launch on Oct. 15, 1998, this first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1073

NASA Image and Video Library

1998-09-15

KENNEDY SPACE CENTER, FLA. -- Workers watch as the fairing for Deep Space 1 is lifted on the Mobile Service Tower to its place on the Boeing Delta 7326 rocket that will launch on Oct. 15, 1998. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1074

NASA Image and Video Library

1998-09-15

KENNEDY SPACE CENTER, FLA. -- The fairing for Deep Space 1 nears the top of the Mobile Service Tower before being attached to the Boeing Delta 7326 rocket that will launch on Oct. 15, 1998. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1072

NASA Image and Video Library

1998-09-15

KENNEDY SPACE CENTER, FLA. -- The fairing for Deep Space 1 is raised upright before being lifted on the Mobile Service Tower to its place on the Boeing Delta 7326 rocket that will launch on Oct. 15, 1998. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc933

NASA Image and Video Library

1998-08-17

KENNEDY SPACE CENTER, FLA. -- Wearing special protective suits, workers ready NASA’s Deep Space 1 spacecraft for prelaunch processing in the Payload Hazardous Servicing Facility at KSC. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA’s New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc931

NASA Image and Video Library

1998-08-17

KENNEDY SPACE CENTER, FLA. -- NASA’s Deep Space 1 spacecraft waits in the Payload Hazardous Servicing Facility for prelaunch processing. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA’s New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc934

NASA Image and Video Library

1998-08-17

KENNEDY SPACE CENTER, FLA. -- Wearing special protective suits, workers ready NASA’s Deep Space 1 spacecraft for prelaunch processing in the Payload Hazardous Servicing Facility at KSC. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA’s New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1049

NASA Image and Video Library

1998-09-11

The first stage of Boeing's Delta 7326 rocket, which will be used to launch the Deep Space 1 spacecraft, arrives at Pad 17A at Cape Canaveral Air Station. Targeted for launch on Oct. 15, 1998, this first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

How to find home backwards? Navigation during rearward homing of Cataglyphis fortis desert ants.

PubMed

Pfeffer, Sarah E; Wittlinger, Matthias

2016-07-15

Cataglyphis ants are renowned for their impressive navigation skills, which have been studied in numerous experiments during forward locomotion. However, the ants' navigational performance during backward homing when dragging large food loads has not been investigated until now. During backward locomotion, the odometer has to deal with unsteady motion and irregularities in inter-leg coordination. The legs' sensory feedback during backward walking is not just a simple reversal of the forward stepping movements: compared with forward homing, ants are facing towards the opposite direction during backward dragging. Hence, the compass system has to cope with a flipped celestial view (in terms of the polarization pattern and the position of the sun) and an inverted retinotopic image of the visual panorama and landmark environment. The same is true for wind and olfactory cues. In this study we analyze for the first time backward-homing ants and evaluate their navigational performance in channel and open field experiments. Backward-homing Cataglyphis fortis desert ants show remarkable similarities in the performance of homing compared with forward-walking ants. Despite the numerous challenges emerging for the navigational system during backward walking, we show that ants perform quite well in our experiments. Direction and distance gauging was comparable to that of the forward-walking control groups. Interestingly, we found that backward-homing ants often put down the food item and performed foodless search loops around the left food item. These search loops were mainly centred around the drop-off position (and not around the nest position), and increased in length the closer the ants came to their fictive nest site. © 2016. Published by The Company of Biologists Ltd.

Special Software for Planetary Image Processing and Research

NASA Astrophysics Data System (ADS)

Zubarev, A. E.; Nadezhdina, I. E.; Kozlova, N. A.; Brusnikin, E. S.; Karachevtseva, I. P.

2016-06-01

The special modules of photogrammetric processing of remote sensing data that provide the opportunity to effectively organize and optimize the planetary studies were developed. As basic application the commercial software package PHOTOMOD™ is used. Special modules were created to perform various types of data processing: calculation of preliminary navigation parameters, calculation of shape parameters of celestial body, global view image orthorectification, estimation of Sun illumination and Earth visibilities from planetary surface. For photogrammetric processing the different types of data have been used, including images of the Moon, Mars, Mercury, Phobos, Galilean satellites and Enceladus obtained by frame or push-broom cameras. We used modern planetary data and images that were taken over the years, shooting from orbit flight path with various illumination and resolution as well as obtained by planetary rovers from surface. Planetary data image processing is a complex task, and as usual it can take from few months to years. We present our efficient pipeline procedure that provides the possibilities to obtain different data products and supports a long way from planetary images to celestial body maps. The obtained data - new three-dimensional control point networks, elevation models, orthomosaics - provided accurate maps production: a new Phobos atlas (Karachevtseva et al., 2015) and various thematic maps that derived from studies of planetary surface (Karachevtseva et al., 2016a).

Celestial polarization patterns sufficient for Viking navigation with the naked eye: detectability of Haidinger's brushes on the sky versus meteorological conditions

PubMed Central

Takács, Péter; Kretzer, Balázs; Szilasi, Szilvia; Száz, Dénes; Farkas, Alexandra; Barta, András

2017-01-01

If a human looks at the clear blue sky from which light with high enough degree of polarization d originates, an 8-shaped bowtie-like figure, the yellow Haidinger's brush can be perceived, the long axis of which points towards the sun. A band of high d arcs across the sky at 90° from the sun. A person can pick two points on that band, observe the yellow brushes and triangulate the position of the sun based on the orientation of the two observed brushes. This method has been suggested to have been used on the open sea by Viking navigators to determine the position of the invisible sun occluded by cloud or fog. Furthermore, Haidinger's brushes can also be used to locate the sun when it is below the horizon or occluded by objects on the horizon. To determine the position of the sun using the celestial polarization pattern, the d of the portion of the sky used must be greater than the viewer's degree of polarization threshold d* for perception of Haidinger's brushes. We studied under which sky conditions the prerequisite d > d* is satisfied. Using full-sky imaging polarimetry, we measured the d-pattern of skylight in the blue (450 nm) spectral range for 1296 different meteorological conditions with different solar elevation angles θ and per cent cloud cover ρ. From the measured d-patterns of a given sky we determined the proportion P of the sky for which d > d*. We obtained that P is the largest at low solar elevations θ ≈ 0° and under totally or nearly clear skies with cloud coverage ρ = 0%, when the sun's position is already easily determined. If the sun is below the horizon (−5° ≤ θ < 0°) during twilight, P = 76.17 ± 4.18% for dmin∗=23% under clear sky conditions. Consequently, the sky-polarimetric Viking navigation based on Haidinger's brushes is most useful after sunset and prior to sunrise, when the sun is not visible and large sky regions are bright, clear and polarized enough for perception of Haidinger's brushes. PMID:28386426

Celestial polarization patterns sufficient for Viking navigation with the naked eye: detectability of Haidinger's brushes on the sky versus meteorological conditions.

PubMed

Horváth, Gábor; Takács, Péter; Kretzer, Balázs; Szilasi, Szilvia; Száz, Dénes; Farkas, Alexandra; Barta, András

2017-02-01

If a human looks at the clear blue sky from which light with high enough degree of polarization d originates, an 8-shaped bowtie-like figure, the yellow Haidinger's brush can be perceived, the long axis of which points towards the sun. A band of high d arcs across the sky at 90° from the sun. A person can pick two points on that band, observe the yellow brushes and triangulate the position of the sun based on the orientation of the two observed brushes. This method has been suggested to have been used on the open sea by Viking navigators to determine the position of the invisible sun occluded by cloud or fog. Furthermore, Haidinger's brushes can also be used to locate the sun when it is below the horizon or occluded by objects on the horizon. To determine the position of the sun using the celestial polarization pattern, the d of the portion of the sky used must be greater than the viewer's degree of polarization threshold d * for perception of Haidinger's brushes. We studied under which sky conditions the prerequisite d  >  d * is satisfied. Using full-sky imaging polarimetry, we measured the d -pattern of skylight in the blue (450 nm) spectral range for 1296 different meteorological conditions with different solar elevation angles θ and per cent cloud cover ρ . From the measured d -patterns of a given sky we determined the proportion P of the sky for which d  >  d *. We obtained that P is the largest at low solar elevations θ  ≈ 0° and under totally or nearly clear skies with cloud coverage ρ  = 0%, when the sun's position is already easily determined. If the sun is below the horizon (-5° ≤  θ  < 0°) during twilight, P  = 76.17 ± 4.18% for [Formula: see text] under clear sky conditions. Consequently, the sky-polarimetric Viking navigation based on Haidinger's brushes is most useful after sunset and prior to sunrise, when the sun is not visible and large sky regions are bright, clear and polarized enough for perception of Haidinger's brushes.

Robust sky light polarization detection with an S-wave plate in a light field camera.

PubMed

Zhang, Wenjing; Zhang, Xuanzhe; Cao, Yu; Liu, Haibo; Liu, Zejin

2016-05-01

The sky light polarization navigator has many advantages, such as low cost, no decrease in accuracy with continuous operation, etc. However, current celestial polarization measurement methods often suffer from low performance when the sky is covered by clouds, which reduce the accuracy of navigation. In this paper we introduce a new method and structure based on a handheld light field camera and a radial polarizer, composed of an S-wave plate and a linear polarizer, to detect the sky light polarization pattern across a wide field of view in a single snapshot. Each micro-subimage has a special intensity distribution. After extracting the texture feature of these subimages, stable distribution information of the angle of polarization under a cloudy sky can be obtained. Our experimental results match well with the predicted properties of the theory. Because the polarization pattern is obtained through image processing, rather than traditional methods based on mathematical computation, this method is less sensitive to errors of pixel gray value and thus has better anti-interference performance.

Star sightings by satellite for image navigation

NASA Technical Reports Server (NTRS)

Kamel, Ahmed A. (Inventor); Ekman, Donald E. (Inventor); Savides, John (Inventor); Zwirn, Gerald J. (Inventor)

1988-01-01

Stars are sensed by one or more instruments (1, 2) on board a three-axis stabilized satellite, for purposes of assisting in image navigation. A star acquistion computer (64), which may be located on the earth, commands the instrument mirror (33, 32) to slew just outside the limb of the earth or other celestial body around which the satellite is orbiting, to look for stars that have been cataloged in a star map stored within the computer (64). The instrument (1, 2) is commanded to dwell for a period of time equal to a star search window time, plus the maximum time the instrument (1, 2) takes to complete a current scan, plus the maximum time it takes for the mirror (33, 32) to slew to the star. When the satellite is first placed in orbit, and following first stationkeeping and eclipse, a special operation is performed in which the star-seeking instrument (1, 2) FOV is broadened. The elevation dimension can be broadened by performing repetitive star seeks; the azimuth dimension can be broadened by lengthening the commanded dwell times.

A demonstration of real-time connected element interferometry for spacecraft navigation

NASA Technical Reports Server (NTRS)

Edwards, C.; Rogstad, D.; Fort, D.; White, L.; Iijima, B.

1992-01-01

Connected element interferometry is a technique of observing a celestial radio source at two spatially separated antennas, and then interfering the received signals to extract the relative phase of the signal at the two antennas. The high precision of the resulting phase delay data type can provide an accurate determination of the angular position of the radio source relative to the baseline vector between the two stations. A connected element interferometer on a 21-km baseline between two antennas at the Deep Space Network's Goldstone, CA tracking complex is developed. Fiber optic links are used to transmit the data at 112 Mbit/sec to a common site for processing. A real-time correlator to process these data in real-time is implemented. The architecture of the system is described, and observational data is presented to characterize the potential performance of such a system. The real-time processing capability offers potential advantages in terms of increased reliability and improved delivery of navigational data for time-critical operations. Angular accuracies of 50-100 nrad are achievable on this baseline.

Explanatory Supplement to the Astronomical Almanac (3rd Edition)

NASA Astrophysics Data System (ADS)

Urban, Sean E.; Seidelmann, P. K.

2014-01-01

Publications and software from the the Astronomical Applications Department of the US Naval Observatory (USNO) are used throughout the world, not only in the Department of Defense for safe navigation, but by many people including other navigators, astronomers, aerospace engineers, and geodesists. Products such as The Nautical Almanac, The Astronomical Almanac, and the Multiyear Interactive Computer Almanac (MICA) are regarded as international standards. To maintain credibility, it is imperative that the methodologies employed and the data used are well documented. "The Explanatory Supplement to the Astronomical Almanac" (hereafter, "The ES") is a major source of such documentation. It is a comprehensive reference book on positional astronomy, covering the theories and algorithms used to produce The Astronomical Almanac, an annual publication produced jointly by the Nautical Almanac Office of USNO and Her Majesty's Nautical Almanac Office (HMNAO). The first edition of The ES appeared in 1961, and the second followed in 1992. Several major changes have taken place in fundamental astronomy since the second edition was published. Advances in radio observations allowed the celestial reference frame to be tied to extragalactic radio sources, thus the International Celestial Reference System replaced the FK5 system. The success of ESA's Hipparcos satellite dramatically altered observational astrometry. Improvements in Earth orientation observations lead to new precession and nutation theories. Additionally, a new positional paradigm, no longer tied to the ecliptic and equinox, was accepted. Largely because of these changes, staff at USNO and HMNAO decided the time was right for the next edition of The ES. The third edition is now available; it is a complete revision of the 1992 book. Along with subjects covered in the previous two editions, the book also contains descriptions of the major advancements in positional astronomy over the last 20 years, some of which are described above. Extensive references to online information are given. This paper will discuss this latest edition of the Explanatory Supplement.

A robust data fusion scheme for integrated navigation systems employing fault detection methodology augmented with fuzzy adaptive filtering

NASA Astrophysics Data System (ADS)

Ushaq, Muhammad; Fang, Jiancheng

2013-10-01

Integrated navigation systems for various applications, generally employs the centralized Kalman filter (CKF) wherein all measured sensor data are communicated to a single central Kalman filter. The advantage of CKF is that there is a minimal loss of information and high precision under benign conditions. But CKF may suffer computational overloading, and poor fault tolerance. The alternative is the federated Kalman filter (FKF) wherein the local estimates can deliver optimal or suboptimal state estimate as per certain information fusion criterion. FKF has enhanced throughput and multiple level fault detection capability. The Standard CKF or FKF require that the system noise and the measurement noise are zero-mean and Gaussian. Moreover it is assumed that covariance of system and measurement noises remain constant. But if the theoretical and actual statistical features employed in Kalman filter are not compatible, the Kalman filter does not render satisfactory solutions and divergence problems also occur. To resolve such problems, in this paper, an adaptive Kalman filter scheme strengthened with fuzzy inference system (FIS) is employed to adapt the statistical features of contributing sensors, online, in the light of real system dynamics and varying measurement noises. The excessive faults are detected and isolated by employing Chi Square test method. As a case study, the presented scheme has been implemented on Strapdown Inertial Navigation System (SINS) integrated with the Celestial Navigation System (CNS), GPS and Doppler radar using FKF. Collectively the overall system can be termed as SINS/CNS/GPS/Doppler integrated navigation system. The simulation results have validated the effectiveness of the presented scheme with significantly enhanced precision, reliability and fault tolerance. Effectiveness of the scheme has been tested against simulated abnormal errors/noises during different time segments of flight. It is believed that the presented scheme can be applied to the navigation system of aircraft or unmanned aerial vehicle (UAV).

Celestial mechanics - Methods of the theory of motion of 'artificial' celestial bodies

NASA Astrophysics Data System (ADS)

Duboshin, G. N.

This book is concerned with the translational motion of 'artificial' celestial bodies. The difference between natural celestial bodies, which are ordinarily considered by celestial mechanics, and 'artificial' celestial bodies is discussed, taking into account hypothetical celestial bodies introduced in connection with mathematical developments and problems, invisible celestial bodies whose existence can be assumed on the basis of some plausible hypothesis, and man-made satellites of the earth. The book consists of two parts. The first part presents introductory material, and examines a number of general mathematical questions to provide a basis for the studies conducted in the second part. Subjects considered in the first part are related to basic problems, integration methods, and perturbation theory. In the second part, attention is given to the motion of artificial celestial bodies in the gravitational field of the basic planet, external perturbations regarding the motion of these bodies, the motion of the bodies in the earth-moon system, and periodic solutions.

Deep Space 1 fairing arrives at pad 17A for launch

NASA Technical Reports Server (NTRS)

1998-01-01

The fairing for Deep Space 1 is raised upright before being lifted on the Mobile Service Tower to its place on the Boeing Delta 7326 rocket that will launch on Oct. 15, 1998. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

Realization of ETRF2000 as a New Terrestrial Reference Frame in Republic of Serbia

NASA Astrophysics Data System (ADS)

Blagojevic, D.; Vasilic, V.

2012-12-01

The International Earth Rotation and Reference Systems Service (IERS) is a joint service of the International Association of Geodesy (IAG) and the International Astronomical Union (IAU), which provides the scientific community with the means for computing the transformation from the International Celestial Reference System (ICRS) to the International Terrestrial Reference System (ITRS). It further maintains the realizations of these systems by appropriate coordinate sets called "frames". The densification of terrestrial frame usually serves as official frame for positioning and navigation tasks within the territory of particular country. One of these densifications was recently performed in order to establish new reference frame for Republic of Serbia. The paper describes related activities resulting in ETRF2000 as a new Serbian terrestrial reference frame.

Deep Space 1 fairing arrives at pad 17A for launch

NASA Technical Reports Server (NTRS)

1998-01-01

Workers watch as the fairing for Deep Space 1 is lifted on the Mobile Service Tower to its place on the Boeing Delta 7326 rocket that will launch on Oct. 15, 1998. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

Deep Space 1 fairing arrives at pad 17A for launch

NASA Technical Reports Server (NTRS)

1998-01-01

Workers check the position of the fairing for Deep Space 1 as it reaches the top of the Mobile Service Tower where it will be attached to the Boeing Delta 7326 rocket that will launch on Oct. 15, 1998. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

Deep Space 1 arrives at KSC and processing begins in the PHSF

NASA Technical Reports Server (NTRS)

1998-01-01

Wearing special protective suits, workers ready NASA's Deep Space 1 spacecraft for prelaunch processing in the Payload Hazardous Servicing Facility at KSC. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

Deep Space 1 arrives at KSC and processing begins in the PHSF

NASA Technical Reports Server (NTRS)

1998-01-01

Wearing special protective suits, workers look over NASA's Deep Space 1 spacecraft before prelaunch processing in the Payload Hazardous Servicing Facility at KSC. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

Deep Space 1 arrives at KSC and processing begins in the PHSF

NASA Technical Reports Server (NTRS)

1998-01-01

Wearing special protective suits, workers maneuver NASA's Deep Space 1 spacecraft into place for prelaunch processing in the Payload Hazardous Servicing Facility at KSC. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

Deep Space 1 arrives at KSC and processing begins in the PHSF

NASA Technical Reports Server (NTRS)

1998-01-01

Wearing special protective suits, workers move NASA's Deep Space 1 spacecraft into another room in the Payload Hazardous Servicing Facility for prelaunch processing . Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

KSC-98pc1053

NASA Image and Video Library

1998-09-11

The first stage of Boeing's Delta 7326 rocket, which will be used to launch the Deep Space 1 spacecraft, is lifted into place above the flame trench at Pad 17A at Cape Canaveral Air Station. Targeted for launch on Oct. 15, 1998, this first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1052

NASA Image and Video Library

1998-09-11

The first stage of Boeing's Delta 7326 rocket, which will be used to launch the Deep Space 1 spacecraft, is lifted into place above the surface of Pad 17A at Cape Canaveral Air Station. Targeted for launch on Oct. 15, 1998, this first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc936

NASA Image and Video Library

1998-08-17

KENNEDY SPACE CENTER, FLA. -- Wearing special protective suits, workers maneuver NASA’s Deep Space 1 spacecraft into place for prelaunch processing in the Payload Hazardous Servicing Facility at KSC. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA’s New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1075

NASA Image and Video Library

1998-09-15

KENNEDY SPACE CENTER, FLA. -- Workers check the position of the fairing for Deep Space 1 as it reaches the top of the Mobile Service Tower where it will be attached to the Boeing Delta 7326 rocket that will launch on Oct. 15, 1998. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc937

NASA Image and Video Library

1998-08-17

KENNEDY SPACE CENTER, FLA. -- Wearing special protective suits, workers look over NASA’s Deep Space 1 spacecraft before prelaunch processing in the Payload Hazardous Servicing Facility at KSC. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA’s New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1151

NASA Image and Video Library

1998-09-22

KENNEDY SPACE CENTER, FLA. -- A technician in the Payload Hazardous Servicing Facility (PHSF) places a paper signed by workers in the PHSF inside a compartment in Deep Space 1. The payload is scheduled to fly on the Boeing Delta 7326 rocket to be launched in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc932

NASA Image and Video Library

1998-08-17

KENNEDY SPACE CENTER, FLA. -- Wearing special protective suits, workers remove the protective covering from NASA’s Deep Space 1 spacecraft in the Payload Hazardous Servicing Facility at KSC to prepare it for prelaunch processing. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA’s New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc935

NASA Image and Video Library

1998-08-17

KENNEDY SPACE CENTER, FLA. -- Wearing special protective suits, workers move NASA’s Deep Space 1 spacecraft into another room in the Payload Hazardous Servicing Facility for prelaunch processing . Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA’s New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1154

NASA Image and Video Library

1998-09-22

KENNEDY SPACE CENTER, FLA. -- In the Payload Hazardous Servicing Facility, workers maneuver Deep Space 1 into place to attach the solar panels. Deep Space 1 is scheduled to fly on the Boeing Delta 7326 rocket to be launched in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

Model-based software engineering for an optical navigation system for spacecraft

NASA Astrophysics Data System (ADS)

Franz, T.; Lüdtke, D.; Maibaum, O.; Gerndt, A.

2017-09-01

The project Autonomous Terrain-based Optical Navigation (ATON) at the German Aerospace Center (DLR) is developing an optical navigation system for future landing missions on celestial bodies such as the moon or asteroids. Image data obtained by optical sensors can be used for autonomous determination of the spacecraft's position and attitude. Camera-in-the-loop experiments in the Testbed for Robotic Optical Navigation (TRON) laboratory and flight campaigns with unmanned aerial vehicle (UAV) are performed to gather flight data for further development and to test the system in a closed-loop scenario. The software modules are executed in the C++ Tasking Framework that provides the means to concurrently run the modules in separated tasks, send messages between tasks, and schedule task execution based on events. Since the project is developed in collaboration with several institutes in different domains at DLR, clearly defined and well-documented interfaces are necessary. Preventing misconceptions caused by differences between various development philosophies and standards turned out to be challenging. After the first development cycles with manual Interface Control Documents (ICD) and manual implementation of the complex interactions between modules, we switched to a model-based approach. The ATON model covers a graphical description of the modules, their parameters and communication patterns. Type and consistency checks on this formal level help to reduce errors in the system. The model enables the generation of interfaces and unified data types as well as their documentation. Furthermore, the C++ code for the exchange of data between the modules and the scheduling of the software tasks is created automatically. With this approach, changing the data flow in the system or adding additional components (e.g., a second camera) have become trivial.

The bird GPS - long-range navigation in migrants.

PubMed

Thorup, Kasper; Holland, Richard A

2009-11-01

Nowadays few people consider finding their way in unfamiliar areas a problem as a GPS (Global Positioning System) combined with some simple map software can easily tell you how to get from A to B. Although this opportunity has only become available during the last decade, recent experiments show that long-distance migrating animals had already solved this problem. Even after displacement over thousands of kilometres to previously unknown areas, experienced but not first time migrant birds quickly adjust their course toward their destination, proving the existence of an experience-based GPS in these birds. Determining latitude is a relatively simple task, even for humans, whereas longitude poses much larger problems. Birds and other animals however have found a way to achieve this, although we do not yet know how. Possible ways of determining longitude includes using celestial cues in combination with an internal clock, geomagnetic cues such as magnetic intensity or perhaps even olfactory cues. Presently, there is not enough evidence to rule out any of these, and years of studying birds in a laboratory setting have yielded partly contradictory results. We suggest that a concerted effort, where the study of animals in a natural setting goes hand-in-hand with lab-based study, may be necessary to fully understand the mechanism underlying the long-distance navigation system of birds. As such, researchers must remain receptive to alternative interpretations and bear in mind that animal navigation may not necessarily be similar to the human system, and that we know from many years of investigation of long-distance navigation in birds that at least some birds do have a GPS - but we are uncertain how it works.

Model-based software engineering for an optical navigation system for spacecraft

NASA Astrophysics Data System (ADS)

Franz, T.; Lüdtke, D.; Maibaum, O.; Gerndt, A.

2018-06-01

The project Autonomous Terrain-based Optical Navigation (ATON) at the German Aerospace Center (DLR) is developing an optical navigation system for future landing missions on celestial bodies such as the moon or asteroids. Image data obtained by optical sensors can be used for autonomous determination of the spacecraft's position and attitude. Camera-in-the-loop experiments in the Testbed for Robotic Optical Navigation (TRON) laboratory and flight campaigns with unmanned aerial vehicle (UAV) are performed to gather flight data for further development and to test the system in a closed-loop scenario. The software modules are executed in the C++ Tasking Framework that provides the means to concurrently run the modules in separated tasks, send messages between tasks, and schedule task execution based on events. Since the project is developed in collaboration with several institutes in different domains at DLR, clearly defined and well-documented interfaces are necessary. Preventing misconceptions caused by differences between various development philosophies and standards turned out to be challenging. After the first development cycles with manual Interface Control Documents (ICD) and manual implementation of the complex interactions between modules, we switched to a model-based approach. The ATON model covers a graphical description of the modules, their parameters and communication patterns. Type and consistency checks on this formal level help to reduce errors in the system. The model enables the generation of interfaces and unified data types as well as their documentation. Furthermore, the C++ code for the exchange of data between the modules and the scheduling of the software tasks is created automatically. With this approach, changing the data flow in the system or adding additional components (e.g., a second camera) have become trivial.

Processing Images of Craters for Spacecraft Navigation

NASA Technical Reports Server (NTRS)

Cheng, Yang; Johnson, Andrew E.; Matthies, Larry H.

2009-01-01

A crater-detection algorithm has been conceived to enable automation of what, heretofore, have been manual processes for utilizing images of craters on a celestial body as landmarks for navigating a spacecraft flying near or landing on that body. The images are acquired by an electronic camera aboard the spacecraft, then digitized, then processed by the algorithm, which consists mainly of the following steps: 1. Edges in an image detected and placed in a database. 2. Crater rim edges are selected from the edge database. 3. Edges that belong to the same crater are grouped together. 4. An ellipse is fitted to each group of crater edges. 5. Ellipses are refined directly in the image domain to reduce errors introduced in the detection of edges and fitting of ellipses. 6. The quality of each detected crater is evaluated. It is planned to utilize this algorithm as the basis of a computer program for automated, real-time, onboard processing of crater-image data. Experimental studies have led to the conclusion that this algorithm is capable of a detection rate >93 percent, a false-alarm rate <5 percent, a geometric error <0.5 pixel, and a position error <0.3 pixel.

Central neural coding of sky polarization in insects.

PubMed

Homberg, Uwe; Heinze, Stanley; Pfeiffer, Keram; Kinoshita, Michiyo; el Jundi, Basil

2011-03-12

Many animals rely on a sun compass for spatial orientation and long-range navigation. In addition to the Sun, insects also exploit the polarization pattern and chromatic gradient of the sky for estimating navigational directions. Analysis of polarization-vision pathways in locusts and crickets has shed first light on brain areas involved in sky compass orientation. Detection of sky polarization relies on specialized photoreceptor cells in a small dorsal rim area of the compound eye. Brain areas involved in polarization processing include parts of the lamina, medulla and lobula of the optic lobe and, in the central brain, the anterior optic tubercle, the lateral accessory lobe and the central complex. In the optic lobe, polarization sensitivity and contrast are enhanced through convergence and opponency. In the anterior optic tubercle, polarized-light signals are integrated with information on the chromatic contrast of the sky. Tubercle neurons combine responses to the UV/green contrast and e-vector orientation of the sky and compensate for diurnal changes of the celestial polarization pattern associated with changes in solar elevation. In the central complex, a topographic representation of e-vector tunings underlies the columnar organization and suggests that this brain area serves as an internal compass coding for spatial directions.

Central neural coding of sky polarization in insects

PubMed Central

Homberg, Uwe; Heinze, Stanley; Pfeiffer, Keram; Kinoshita, Michiyo; el Jundi, Basil

2011-01-01

Many animals rely on a sun compass for spatial orientation and long-range navigation. In addition to the Sun, insects also exploit the polarization pattern and chromatic gradient of the sky for estimating navigational directions. Analysis of polarization–vision pathways in locusts and crickets has shed first light on brain areas involved in sky compass orientation. Detection of sky polarization relies on specialized photoreceptor cells in a small dorsal rim area of the compound eye. Brain areas involved in polarization processing include parts of the lamina, medulla and lobula of the optic lobe and, in the central brain, the anterior optic tubercle, the lateral accessory lobe and the central complex. In the optic lobe, polarization sensitivity and contrast are enhanced through convergence and opponency. In the anterior optic tubercle, polarized-light signals are integrated with information on the chromatic contrast of the sky. Tubercle neurons combine responses to the UV/green contrast and e-vector orientation of the sky and compensate for diurnal changes of the celestial polarization pattern associated with changes in solar elevation. In the central complex, a topographic representation of e-vector tunings underlies the columnar organization and suggests that this brain area serves as an internal compass coding for spatial directions. PMID:21282171

Navigation in wood ants Formica japonica: context dependent use of landmarks.

PubMed

Fukushi, Tsukasa; Wehner, Rüdiger

2004-09-01

Wood ants Formica japonica can steer their outbound (foraging) and inbound (homing) courses without using celestial compass information, by relying exclusively on landmark cues. This is shown by training ants to run back and forth between the nest and an artificial feeder, and later displacing the trained ants either from the nest (when starting their foraging runs: outbound full-vector ants) or from the feeder (when starting their home runs: inbound full-vector ants) to various nearby release sites. In addition, ants that have already completed their foraging and homing runs are displaced after arrival either at the feeder (outbound zero-vector ants) or at the nest (inbound zero-vector ants), respectively, to the very same release sites. Upon release, the full-vector ants steer their straight courses by referring to panoramic landmark cues, while the zero-vector ants presented with the very same visual scenery immediately search for local landmark cues defining their final goal. Hence, it depends on the context, in this case on the state of the forager's round-trip cycle, what visual cues are picked out from a given set of landmarks and used for navigation.

A new navigational mechanism mediated by ant ocelli.

PubMed

Schwarz, Sebastian; Wystrach, Antoine; Cheng, Ken

2011-12-23

Many animals rely on path integration for navigation and desert ants are the champions. On leaving the nest, ants continuously integrate their distance and direction of travel so that they always know their current distance and direction from the nest and can take a direct path to home. Distance information originates from a step-counter and directional information is based on a celestial compass. So far, it has been assumed that the directional information obtained from ocelli contribute to a single global path integrator, together with directional information from the dorsal rim area (DRA) of the compound eyes and distance information from the step-counter. Here, we show that ocelli mediate a distinct compass from that mediated by the compound eyes. After travelling a two-leg outbound route, untreated foragers headed towards the nest direction, showing that both legs of the route had been integrated. In contrast, foragers with covered compound eyes but uncovered ocelli steered in the direction opposite to the last leg of the outbound route. Our findings suggest that, unlike the DRA, ocelli cannot by themselves mediate path integration. Instead, ocelli mediate a distinct directional system, which buffers the most recent leg of a journey.

IIPImage: Large-image visualization

NASA Astrophysics Data System (ADS)

Pillay, Ruven

2014-08-01

IIPImage is an advanced high-performance feature-rich image server system that enables online access to full resolution floating point (as well as other bit depth) images at terabyte scales. Paired with the VisiOmatic (ascl:1408.010) celestial image viewer, the system can comfortably handle gigapixel size images as well as advanced image features such as both 8, 16 and 32 bit depths, CIELAB colorimetric images and scientific imagery such as multispectral images. Streaming is tile-based, which enables viewing, navigating and zooming in real-time around gigapixel size images. Source images can be in either TIFF or JPEG2000 format. Whole images or regions within images can also be rapidly and dynamically resized and exported by the server from a single source image without the need to store multiple files in various sizes.

The first stage of Boeing's Delta 7326 arrives at Pad 17A, CCAS, in preparation for the Deep Space 1

NASA Technical Reports Server (NTRS)

1998-01-01

The first stage of Boeing's Delta 7326 rocket, which will be used to launch the Deep Space 1 spacecraft, arrives at Pad 17A at Cape Canaveral Air Station. Targeted for launch on Oct. 15, 1998, this first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

Deep Space 1 arrives at KSC and processing begins in the PHSF

NASA Technical Reports Server (NTRS)

1998-01-01

Wearing special protective suits, workers remove the protective covering from NASA's Deep Space 1 spacecraft in the Payload Hazardous Servicing Facility at KSC to prepare it for prelaunch processing. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

KSC-98pc1152

NASA Image and Video Library

1998-09-22

KENNEDY SPACE CENTER, FLA. -- Workers in the Payload Hazardous Servicing Facility (PHSF) place a rolled-up document inside Deep Space 1. The paper was signed by the workers in the PHSF. Deep Space 1 is scheduled to fly on the Boeing Delta 7326 rocket to be launched in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1071

NASA Image and Video Library

1998-09-15

KENNEDY SPACE CENTER, FLA. -- Arriving in the early morning hours at Pad 17A, Cape Canaveral Air Station, the fairing for Deep Space 1 is lifted from the truck before being raised to its place on the Boeing Delta 7326 rocket that will launch on Oct. 15, 1998. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1153

NASA Image and Video Library

1998-09-22

KENNEDY SPACE CENTER, FLA. -- Through the open panel of Deep Space 1 can be seen the rolled-up document (on the left) signed by the workers in the Payload Hazardous Servicing Facility. Deep Space 1 is scheduled to fly on the Boeing Delta 7326 rocket to be launched in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1382

NASA Image and Video Library

1998-10-24

KENNEDY SPACE CENTER, FLA. -- Lighting up the launch pad, a Boeing Delta II (7326) rocket propels Deep Space 1 through the morning clouds after liftoff from Launch Complex 17A, Cape Canaveral Air Station. The first flight in NASA's New Millennium Program, the spacecraft is designed to validate 12 new technologies for scientific space missions of the next century, including the ion propulsion engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

Observation of Celestial Phenomena in Ancient China

NASA Astrophysics Data System (ADS)

Sun, Xiaochun

Because of the need for calendar-making and portent astrology, the Chinese were diligent and meticulous observers of celestial phenomena. China has maintained the longest continuous historical records of celestial phenomena in the world. Extraordinary or abnormal celestial events were particularly noted because of their astrological significance. The historical records cover various types of celestial phenomena, which include solar and lunar eclipses, sunspots, "guest stars" (novae or supernovae as we understand today), comets and meteors, and all kinds of planetary phenomena. These records provide valuable historical data for astronomical studies today.

Protection of celestial environments and the law of outer space

NASA Astrophysics Data System (ADS)

Tennen, Leslie; Race, Margaret

The law of outer space expressly addresses the matter of preservation and protection of natural celestial environments from harmful contamination and disruption by mankind in the explo-ration and use of outer space, including the moon and other celestial bodies. The Outer Space Treaty, however, does not prohibit all human impact to an extraterrestrial environment, but rather permits a wide range of activities that could have significant environmental ramifications. This legal regime may be in conflict with the interests of preserving celestial environments for scientific research, especially when considered in relation to activities conducted for commercial purposes. Nevertheless, the Moon Agreement provides a mechanism by which special protective measures can be implemented to protect particular areas of the moon and other celestial bodies for scientific investigation. This paper examines the current status of the law of outer space vis-a-vis the protection and preservation of natural celestial environments. Particular emphasis is placed on the policies on which the legal obligations are based, together with consideration of the non-appropriation principle, and the commercial use of lunar and other celestial resources and areas. In addition, the concepts of international scientific preserves, special regions, keep out zones, and planetary parks are compared and evaluated as potential means to limit the disturbance to celestial environments caused by the activities of mankind.

Microarsecond models for the celestial motions of the CIP and CEO

NASA Astrophysics Data System (ADS)

Capitaine, N.

2004-09-01

The Celestial intermediate pole (CIP) and Celestial ephemeris (orintermediate) origin (CEO/CIO) have been adopted by the IAU (c.f. IAU2000 Resolution B1.8) as the celestial pole and origin, respectively,to be used for realizing the intermediate celestial system between theInternational Terrestrial System (ITRS) and Geocentric CelestialReference System (GCRS). Resolution B1.8 has also recommended that theInternational Earth Rotation and Reference Systems Service (IERS)continue to provide users with data and algorithms for the conventionaltransformation. The IAU 2000 Resolutions have been implemented in theIERS 2003 Conventions including Tables and routines that provide thecelestial motions of the CIP and the CEO with a theoretical accuracy ofone microarcsecond after one century using either the classical or thenew transformation. This paper reports on the method used for achievingthis accuracy in the positions of the CIP and CIO and on the differencebetween this rigorous procedure and the pre-2003 classical one.

Orientation and navigation during adult transport between nests in the ant Cataglypis iberica.

PubMed

Fourcassie, V; Dahbi, A; Cerdá, X

2000-08-01

Cataglyphis iberica is a polydomous ant species in which adult transports between nests are frequently observed. When pairs of workers were captured and released at the same location, the transporters (Ts) field directly towards their destination nest and reached it in most of the cases. The transportees (Te), on the other hand, fled in the opposite direction and only a third of them eventually reached their nest of departure. Additional experiments suggest that this result may be explained by the fact that the Ts ants have a memory of the compass direction of the nest they are heading to and that they adjust their course by using a sequence of memorised landmarks. As regards to the Te, the reversal of their direction of transport seems to be based essentially on celestial cues.

New International Agreements About Space Techniques Among Argentina, China and France

NASA Astrophysics Data System (ADS)

Pacheco, A. M.; Podestá, R.; Actis, E.; Adarvez, S.; Quinteros, J.; Li, J.; Saunier, J.; Podestá, F.; Ramos, F.; Aguilera, J.; Sosa, G.; Hauser, D.

2018-01-01

The International Earth Rotation and Reference Systems (IERS) is in charge of defining and materializing celestial reference systems (ICRS - ICRF) and terrestrial reference systems (ITRS - ITRF). In order to perform this task it uses data from the following techniques: Very Long Baseline Interferometry (VLBI), Satellite Laser Ranging (SLR), Global Navigation Satellite System (GNSS) and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS). Nowadays, the Observatorio Astronómico Félix Aguilar (OAFA) has two instruments with these advanced techniques: SLR and a permanent GNSS station. In the nearby future a 40 m diameter radio telescope will be available that will be operated in VLBI mode along with a DORIS buoy which will be co-localized with a SLR telescope and GNSS antennas. In this way OAFA will become a zero station, first class, of the ITRF 2014 frame.

Design and performance of the GAMMA-400 gamma-ray telescope for dark matter searches

NASA Astrophysics Data System (ADS)

Galper, A. M.; Adriani, O.; Aptekar, R. L.; Arkhangelskaja, I. V.; Arkhangelskiy, A. I.; Boezio, M.; Bonvicini, V.; Boyarchuk, K. A.; Fradkin, M. I.; Gusakov, Yu. V.; Kaplin, V. A.; Kachanov, V. A.; Kheymits, M. D.; Leonov, A. A.; Longo, F.; Mazets, E. P.; Maestro, P.; Marrocchesi, P.; Mereminskiy, I. A.; Mikhailov, V. V.; Moiseev, A. A.; Mocchiutti, E.; Mori, N.; Moskalenko, I. V.; Naumov, P. Yu.; Papini, P.; Picozza, P.; Rodin, V. G.; Runtso, M. F.; Sparvoli, R.; Spillantini, P.; Suchkov, S. I.; Tavani, M.; Topchiev, N. P.; Vacchi, A.; Vannuccini, E.; Yurkin, Yu. T.; Zampa, N.; Zverev, V. G.; Zirakashvili, V. N.

2013-02-01

The GAMMA-400 gamma-ray telescope is designed to measure the fluxes of gamma-rays and cosmic-ray electrons + positrons, which can be produced by annihilation or decay of the dark matter particles, as well as to survey the celestial sphere in order to study point and extended sources of gamma-rays, measure energy spectra of Galactic and extragalactic diffuse gamma-ray emission, gamma-ray bursts, and gamma-ray emission from the Sun. GAMMA-400 covers the energy range from 100 MeV to 3000 GeV. Its angular resolution is ~0.01° (Eγ > 100 GeV), the energy resolution ~1% (Eγ > 10 GeV), and the proton rejection factor ~106. GAMMA-400 will be installed on the Russian space platform Navigator. The beginning of observations is planned for 2018.

An adaptive filter method for spacecraft using gravity assist

NASA Astrophysics Data System (ADS)

Ning, Xiaolin; Huang, Panpan; Fang, Jiancheng; Liu, Gang; Ge, Shuzhi Sam

2015-04-01

Celestial navigation (CeleNav) has been successfully used during gravity assist (GA) flyby for orbit determination in many deep space missions. Due to spacecraft attitude errors, ephemeris errors, the camera center-finding bias, and the frequency of the images before and after the GA flyby, the statistics of measurement noise cannot be accurately determined, and yet have time-varying characteristics, which may introduce large estimation error and even cause filter divergence. In this paper, an unscented Kalman filter (UKF) with adaptive measurement noise covariance, called ARUKF, is proposed to deal with this problem. ARUKF scales the measurement noise covariance according to the changes in innovation and residual sequences. Simulations demonstrate that ARUKF is robust to the inaccurate initial measurement noise covariance matrix and time-varying measurement noise. The impact factors in the ARUKF are also investigated.

Is time enough in order to know where you are?

NASA Astrophysics Data System (ADS)

Tartaglia, Angelo

2013-09-01

This talk discusses various aspects of the structure of space-time presenting mechanisms leading to the explanation of the "rigidity" of the manifold and to the emergence of time, i.e. of the Lorentzian signature. The proposed ingredient is the analog, in four dimensions, of the deformation energy associated with the common three-dimensional elasticity theory. The inclusion of this additional term in the Lagrangian of empty space-time accounts for gravity as an emergent feature from the microscopic structure of space-time. Once time has legitimately been introduced a global positioning method based on local measurements of proper times between the arrivals of electromagnetic pulses from independent distant sources is presented. The method considers both pulsars as well as artificial emitters located on celestial bodies of the solar system as pulsating beacons to be used for navigation and positioning.

KSC-98pc1381

NASA Image and Video Library

1998-10-24

KENNEDY SPACE CENTER, FLA. -- A Boeing Delta II (7326) rocket hurls Deep Space 1 through the morning clouds after liftoff, creating sun-challenging light with its exhaust, from Launch Complex 17A, Cape Canaveral Air Station. The first flight in NASA's New Millennium Program, the spacecraft is designed to validate 12 new technologies for scientific space missions of the next century, including the ion propulsion engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1385

NASA Image and Video Library

1998-10-24

KENNEDY SPACE CENTER, FLA. -- In a view from Press Site 1 at Cape Canaveral Air Station, a Boeing Delta II (7326) rocket lights up the ground as it propels Deep Space 1 into the sky after liftoff from Launch Complex 17A. The first flight in NASA's New Millennium Program, the spacecraft is designed to validate 12 new technologies for scientific space missions of the next century, including the ion propulsion engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1383

NASA Image and Video Library

1998-10-24

KENNEDY SPACE CENTER, FLA. -- Lighting up the launch pad below, a Boeing Delta II (7326) rocket is silhouetted in the morning light as it propels Deep Space 1 into the sky after liftoff from Launch Complex 17A, Cape Canaveral Air Station. The first flight in NASA's New Millennium Program, the spacecraft is designed to validate 12 new technologies for scientific space missions of the next century, including the ion propulsion engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1384

NASA Image and Video Library

1998-10-24

KENNEDY SPACE CENTER, FLA. -- A Boeing Delta II (7326) rocket lights up the clouds of exhaust below as it propels Deep Space 1 into the sky after liftoff from Launch Complex 17A, Cape Canaveral Air Station. The first flight in NASA's New Millennium Program, the spacecraft is designed to validate 12 new technologies for scientific space missions of the next century, including the ion propulsion engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1386

NASA Image and Video Library

1998-10-24

KENNEDY SPACE CENTER, FLA. -- Photographed at Launch Complex 17, Cape Canaveral Station, just after midnight on launch day, Boeing's Delta II rocket is bathed in light as it awaits its destiny, hurling NASA's Deep Space 1 into space. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the ion propulsion engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pa001

NASA Image and Video Library

1998-10-24

In a view from Press Site 1 at Cape Canaveral Air Station, a Boeing Delta II (7326) rocket is framed between the ghostly silhouettes of two press photographers as it launches Deep Space 1 on its mission from Launch Complex 17A. The first flight in NASA's New Millennium Program, the spacecraft is designed to validate 12 new technologies for scientific space missions of the next century, including the ion propulsion engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

The first stage of Boeing's Delta 7326 arrives at Pad 17A, CCAS, in preparation for the Deep Space 1

NASA Technical Reports Server (NTRS)

1998-01-01

The first stage of Boeing's Delta 7326 rocket, which will be used to launch the Deep Space 1 spacecraft, is lifted into place above the surface of Pad 17A at Cape Canaveral Air Station. Targeted for launch on Oct. 15, 1998, this first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

Polarization-sensitive descending neurons in the locust: connecting the brain to thoracic ganglia.

PubMed

Träger, Ulrike; Homberg, Uwe

2011-02-09

Many animal species, in particular insects, exploit the E-vector pattern of the blue sky for sun compass navigation. Like other insects, locusts detect dorsal polarized light via photoreceptors in a specialized dorsal rim area of the compound eye. Polarized light information is transmitted through several processing stages to the central complex, a brain area involved in the control of goal-directed orientation behavior. To investigate how polarized light information is transmitted to thoracic motor circuits, we studied the responses of locust descending neurons to polarized light. Three sets of polarization-sensitive descending neurons were characterized through intracellular recordings from axonal fibers in the neck connectives combined with single-cell dye injections. Two descending neurons from the brain, one with ipsilaterally and the second with contralaterally descending axon, are likely to bridge the gap between polarization-sensitive neurons in the brain and thoracic motor centers. In both neurons, E-vector tuning changed linearly with daytime, suggesting that they signal time-compensated spatial directions, an important prerequisite for navigation using celestial signals. The third type connects the suboesophageal ganglion with the prothoracic ganglion. It showed no evidence for time compensation in E-vector tuning and might play a role in flight stabilization and control of head movements.

Frontiers in Relativistic Celestial Mechanics, Vol. 2, Applications and Experiments

NASA Astrophysics Data System (ADS)

Kopeikin, Sergei

2014-08-01

Relativistic celestial mechanics - investigating the motion celestial bodies under the influence of general relativity - is a major tool of modern experimental gravitational physics. With a wide range of prominent authors from the field, this two-volume series consists of reviews on a multitude of advanced topics in the area of relativistic celestial mechanics - starting from more classical topics such as the regime of asymptotically-flat spacetime, light propagation and celestial ephemerides, but also including its role in cosmology and alternative theories of gravity as well as modern experiments in this area. This second volume of a two-volume series covers applications of the theory as well as experimental verifications. From tools to determine light travel times in curved space-time to laser ranging between earth and moon and between satellites, and impacts on the definition of time scales and clock comparison techniques, a variety of effects is discussed. On the occasion of his 80-th birthday, these two volumes honor V. A. Brumberg - one of the pioneers in modern relativistic celestial mechanics. Contributions include: J. Simon, A. Fienga: Victor Brumberg and the French school of analytical celestial mechanics T. Fukushima: Elliptic functions and elliptic integrals for celestial mechanics and dynamical astronomy P. Teyssandier: New tools for determining the light travel time in static, spherically symmetric spacetimes beyond the order G2 J. Müller, L. Biskupek, F. Hofmann and E. Mai: Lunar laser ranging and relativity N. Wex: Testing relativistic celestial mechanics with radio pulsars I. Ciufolini et al.: Dragging of inertial frames, fundamental physics, and satellite laser ranging G. Petit, P. Wolf, P. Delva: Atomic time, clocks, and clock comparisons in relativistic spacetime: a review

VLBI tracking of GNSS satellites: recent achievements

NASA Astrophysics Data System (ADS)

Liu, Li; Heinkelmann, Robert; Tornatore, Vincenza; Li, Jinling; Mora-Diaz, Julian; Nilsson, Tobias; Karbon, Maria; Raposo-Pulido, Virginia; Soja, Benedikt; Xu, Minghui; Lu, Cuixian; Schuh, Harald

2014-05-01

While the ITRF (International Terrestrial Reference Frame) is realized by the combination of the various space geodetic techniques, VLBI (Very Long Baseline Interferometry) is the only technique for determining the ICRF (International Celestial Reference Frame) through its observations of extragalactic radio sources. Therefore, small inconsistencies between the two important frames do exist. According to recent comparisons of parameters derived by GNSS (Global Navigation Satellite Systems) and VLBI (e.g. troposphere delays, gradients, UT1-UTC), evidences of discrepancies obtained by the vast amounts of data become obvious. Terrestrial local ties can provide a way to interlink the otherwise independent technique-specific reference frames but only to some degree. It is evident that errors in the determination of the terrestrial ties, e.g. due to the errors when transforming the locally surveyed coordinates into global Cartesian three dimensional coordinates, introduce significant errors in the combined analysis of space geodetic techniques. A new concept for linking the space geodetic techniques might be to introduce celestial ties, e.g. realized by technique co-location on board of satellites. A small satellite carrying a variety of space geodetic techniques is under investigation at GFZ. Such a satellite would provide a new observing platform with its own additional unknowns, such as the orbit or atmospheric drag parameters. A link of the two techniques VLBI and GNSS might be achieved in a more direct way as well: by VLBI tracking of GNSS satellites. Several tests of this type of observation were already successfully carried out. This new kind of hybrid VLBI-GNSS observation would comprise a new direct inter-technique tie without the involvement of surveying methods and would enable improving the consistency of the two space geodetic techniques VLBI and GNSS, in particular of their celestial frames. Recently the radio telescopes Wettzell and Onsala have successfully observed a GNSS satellite for the first time, using also new receiver developments, done at Wettzell. In this contribution we want to develop the motivation for this kind of innovative observation and we will show first results of the test observations.

Relation between the celestial reference system and the terrestrial reference system of a rigid earth

NASA Astrophysics Data System (ADS)

Aoki, Shinko

The equations of motion for a rigid earth under the influence of the sun and moon are solved analytically up to the second-order perturbation, and the results are used to elucidate the relationship between the celestial and terrestrial reference systems. The derivations are given in detail, and consideration is given to celestial-ephemeris and instantaneous-rotation poles, wobble, the departure point as the origin of the local inertial system, the precession-nutation matrix, and techniques for improving the celestial reference system.

Psychophysical study of the visual sun location in pictures of cloudy and twilight skies inspired by Viking navigation.

PubMed

Barta, András; Horváth, Gábor; Meyer-Rochow, Victor Benno

2005-06-01

In the late 1960s it was hypothesized that Vikings had been able to navigate the open seas, even when the sun was occluded by clouds or below the sea horizon, by using the angle of polarization of skylight. To detect the direction of skylight polarization, they were thought to have made use of birefringent crystals, called "sun-stones," and a large part of the scientific community still firmly believe that Vikings were capable of polarimetric navigation. However, there are some critics who treat the usefulness of skylight polarization for orientation under partly cloudy or twilight conditions with extreme skepticism. One of their counterarguments has been the assumption that solar positions or solar azimuth directions could be estimated quite accurately by the naked eye, even if the sun was behind clouds or below the sea horizon. Thus under partly cloudy or twilight conditions there might have been no serious need for a polarimetric method to determine the position of the sun. The aim of our study was to test quantitatively the validity of this qualitative counterargument. In our psychophysical laboratory experiments, test subjects were confronted with numerous 180 degrees field-of-view color photographs of partly cloudy skies with the sun occluded by clouds or of twilight skies with the sun below the horizon. The task of the subjects was to guess the position or the azimuth direction of the invisible sun with the naked eye. We calculated means and standard deviations of the estimated solar positions and azimuth angles to characterize the accuracy of the visual sun location. Our data do not support the common belief that the invisible sun can be located quite accurately from the celestial brightness and/or color patterns under cloudy or twilight conditions. Although our results underestimate the accuracy of visual sun location by experienced Viking navigators, the mentioned counterargument cannot be taken seriously as a valid criticism of the theory of the alleged polarimetric Viking navigation. Our results, however, do not bear on the polarimetric theory itself.

Psychophysical study of the visual sun location in pictures of cloudy and twilight skies inspired by Viking navigation

NASA Astrophysics Data System (ADS)

Barta, András; Horváth, Gábor; Benno Meyer-Rochow, Victor

2005-06-01

In the late 1960s it was hypothesized that Vikings had been able to navigate the open seas, even when the sun was occluded by clouds or below the sea horizon, by using the angle of polarization of skylight. To detect the direction of skylight polarization, they were thought to have made use of birefringent crystals, called "sunstones," and a large part of the scientific community still firmly believe that Vikings were capable of polarimetric navigation. However, there are some critics who treat the usefulness of skylight polarization for orientation under partly cloudy or twilight conditions with extreme skepticism. One of their counterarguments has been the assumption that solar positions or solar azimuth directions could be estimated quite accurately by the naked eye, even if the sun was behind clouds or below the sea horizon. Thus under partly cloudy or twilight conditions there might have been no serious need for a polarimetric method to determine the position of the sun. The aim of our study was to test quantitatively the validity of this qualitative counterargument. In our psychophysical laboratory experiments, test subjects were confronted with numerous 180° field-of-view color photographs of partly cloudy skies with the sun occluded by clouds or of twilight skies with the sun below the horizon. The task of the subjects was to guess the position or the azimuth direction of the invisible sun with the naked eye. We calculated means and standard deviations of the estimated solar positions and azimuth angles to characterize the accuracy of the visual sun location. Our data do not support the common belief that the invisible sun can be located quite accurately from the celestial brightness and/or color patterns under cloudy or twilight conditions. Although our results underestimate the accuracy of visual sun location by experienced Viking navigators, the mentioned counterargument cannot be taken seriously as a valid criticism of the theory of the alleged polarimetric Viking navigation. Our results, however, do not bear on the polarimetric theory itself.

Results of PRISMA/FFIORD extended mission and applicability to future formation flying and active debris removal missions

NASA Astrophysics Data System (ADS)

Delpech, Michel; Berges, Jean-Claude; Karlsson, Thomas; Malbet, Fabien

2013-07-01

CNES performed several experiments during the extended PRISMA mission which started in August 2011. A first session in October 2011 addressed two objectives: 1) demonstrate angles-only navigation to rendezvous with a non-cooperative object; 2) exercise transitions between RF-based and vision-based control during final formation acquisition. A complementary experiment in September 2012 mimicked some future astrometry mission and implemented the manoeuvres required to point the two satellite axis to a celestial target and maintain it fixed during some observation period. In the first sections, the paper presents the experiment motivations, describes its main design features including the guidance and control algorithms evolutions and provides a synthesis of the most significant results along with a discussion of the lessons learned. In the last part, the paper evokes the applicability of these experiment results to some active debris removal mission concept that is currently being studied.

Development of a high-precision selenodetic coordinate system for the physical surface of the Moon based on LED beacons on its surface

NASA Astrophysics Data System (ADS)

Shirenin, A. M.; Mazurova, E. M.; Bagrov, A. V.

2016-11-01

The paper presents a mathematical algorithm for processing an array of angular measurements of light beacons on images of the lunar surface onboard a polar artificial lunar satellite (PALS) during the Luna-Glob mission and coordinate-time referencing of the PALS for the development of reference selenocentric coordinate systems. The algorithm makes it possible to obtain angular positions of point light beacons located on the surface of the Moon in selenocentric celestial coordinates. The operation of measurement systems that determine the position and orientation of the PALS during its active existence have been numerically simulated. Recommendations have been made for the optimal use of different types of measurements, including ground radio trajectory measurements, navigational star sensors based on the onboard star catalog, gyroscopic orientation systems, and space videos of the lunar surface.

Design and Performance of the GAMMA-400 Gamma-Ray Telescope for Dark Matter Searches

NASA Technical Reports Server (NTRS)

Galper, A.M.; Adriani, O.; Aptekar, R. L.; Arkhangelskaja, I. V.; Arkhangelskiy, A.I.; Boezio, M.; Bonvicini, V.; Boyarchuk, K. A.; Fradkin, M. I.; Gusakov, Yu. V.;

Design and Performance of the GAMMA-400 Gamma-Ray Telescope for Dark Matter Searches

NASA Technical Reports Server (NTRS)

Galper, A. M.; Adriani, O.; Aptekar, R. L.; Arkhangelskaja, I. V.; Arkhangelskiy, A. I.; Boezio, M.; Bonvicini, V.; Boyarchuk, K. A.; Fradkin, M. I.; Gusakov, Yu V.;

Apollo experience report: The application of a computerized visualization capability to lunar missions

NASA Technical Reports Server (NTRS)

Hyle, C. T.; Lunde, A. N.

1972-01-01

The development of a computerized capability to depict views from the Apollo spacecraft during a lunar mission was undertaken before the Apollo 8 mission. Such views were considered valuable because of the difficulties in visualizing the complex geometry of the Earth, Moon, Sun, and spacecraft. Such visualization capability originally was desired for spacecraft attitude verification and contingency situations. Improvements were added for later Apollo flights, and results were adopted for several real time and preflight applications. Some specific applications have included crewmember and ground control personnel familiarization, nominal and contingency mission planning, definition of secondary attitude checks for all major thrust maneuvers, and preflight star selection for navigation and for platform alinement. The use of this computerized visualization capability should prove valuable for any future space program as an aid to understanding the geometrical relationships between the spacecraft and the celestial surroundings.

KSC-98pc1182

NASA Image and Video Library

1998-09-29

KENNEDY SPACE CENTER, FLA. -- In the Payload Hazardous Servicing Facility, workers complete the insulation of Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, Cape Canaveral Air Station, in October. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches

KSC-98pc1157

NASA Image and Video Library

1998-09-22

KENNEDY SPACE CENTER, FLA. -- Workers in the Payload Hazardous Servicing Facility maneuver a second solar panel to attach it to Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, Cape Canaveral Air Station, in October. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches

KSC-98pc1178

NASA Image and Video Library

1998-09-29

KENNEDY SPACE CENTER, FLA. -- In the Payload Hazardous Servicing Facility, KSC workers place insulating blankets on Deep Space 1 to prepare it for launch. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, Cape Canaveral Air Station, in October. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches

KSC-98pc1175

NASA Image and Video Library

1998-09-29

KENNEDY SPACE CENTER, FLA. -- Workers in the Payload Hazardous Servicing Facility install blanket insulation on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, Cape Canaveral Air Station, in October. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches

KSC-98pc1158

NASA Image and Video Library

1998-09-29

KENNEDY SPACE CENTER, FLA. -- Workers in the Payload Hazardous Servicing Facility get ready to attach a second solar panel to Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta II rocket from Launch Pad 17A, Cape Canaveral Air Station, in October. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches

KSC-98pc1174

NASA Image and Video Library

1998-09-29

KENNEDY SPACE CENTER, FLA. -- Workers in the Payload Hazardous Servicing Facility begin installing blanket insulation on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, Cape Canaveral Air Station, in October. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches

KSC-98pc1176

NASA Image and Video Library

1998-09-29

KENNEDY SPACE CENTER, FLA. -- Workers in the Payload Hazardous Servicing Facility finish installing blanket insulation on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, Cape Canaveral Air Station, in October. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches

The research of the coupled orbital-attitude controlled motion of celestial body in the neighborhood of the collinear libration point L1

NASA Astrophysics Data System (ADS)

Shmyrov, A.; Shmyrov, V.; Shymanchuk, D.

2017-10-01

This article considers the motion of a celestial body within the restricted three-body problem of the Sun-Earth system. The equations of controlled coupled attitude-orbit motion in the neighborhood of collinear libration point L1 are investigated. The translational orbital motion of a celestial body is described using Hill's equations of circular restricted three-body problem of the Sun-Earth system. Rotational orbital motion is described using Euler's dynamic equations and quaternion kinematic equation. We investigate the problem of stability of celestial body rotational orbital motion in relative equilibrium positions and stabilization of celestial body rotational orbital motion with proposed control laws in the neighborhood of collinear libration point L1. To study stabilization problem, Lyapunov function is constructed in the form of the sum of the kinetic energy and special "kinematic function" of the Rodriguez-Hamiltonian parameters. Numerical modeling of the controlled rotational motion of a celestial body at libration point L1 is carried out. The numerical characteristics of the control parameters and rotational motion are given.

Celestial bodies macroscopic movement is due to the radiation

NASA Astrophysics Data System (ADS)

Yongquan, Han

2016-03-01

The star is radiate, also as the planet. In fact, all the real objects are radiate, but the strength of the radiation is different. Radiation will reduce the quality of the object, but time is not long enough to reduce the mass of the subject, so it is difficult for us to observe. Due to the large object lifecycle, to study the changing rule of the object, we must consider the radiation on the quality of the celestial bodies, and the outer space radiate particles' motion, also consider objects interact with objects of radiation. The reason Celestial bodies moves is that the radiation of those Celestial bodies Interact with each other, Celestial bodies macroscopic movement is due to the radiation. The earth's rotation and revolution is a measure of the survive ability. Author: hanyongquan TEL: 15611860790

Modelling of celestial backgrounds

NASA Astrophysics Data System (ADS)

Hickman, Duncan L.; Smith, Moira I.; Lim, Jae-Wan; Jeon, Yun-Ho

2018-05-01

For applications where a sensor's image includes the celestial background, stars and Solar System Bodies compromise the ability of the sensor system to correctly classify a target. Such false targets are particularly significant for the detection of weak target signatures which only have a small relative angular motion. The detection of celestial features is well established in the visible spectral band. However, given the increasing sensitivity and low noise afforded by emergent infrared focal plane array technology together with larger and more efficient optics, the signatures of celestial features can also impact performance at infrared wavelengths. A methodology has been developed which allows the rapid generation of celestial signatures in any required spectral band using star data from star catalogues and other open-source information. Within this paper, the radiometric calculations are presented to determine the irradiance values of stars and planets in any spectral band.

Neural coding underlying the cue preference for celestial orientation

PubMed Central

el Jundi, Basil; Warrant, Eric J.; Byrne, Marcus J.; Khaldy, Lana; Baird, Emily; Smolka, Jochen; Dacke, Marie

2015-01-01

Diurnal and nocturnal African dung beetles use celestial cues, such as the sun, the moon, and the polarization pattern, to roll dung balls along straight paths across the savanna. Although nocturnal beetles move in the same manner through the same environment as their diurnal relatives, they do so when light conditions are at least 1 million-fold dimmer. Here, we show, for the first time to our knowledge, that the celestial cue preference differs between nocturnal and diurnal beetles in a manner that reflects their contrasting visual ecologies. We also demonstrate how these cue preferences are reflected in the activity of compass neurons in the brain. At night, polarized skylight is the dominant orientation cue for nocturnal beetles. However, if we coerce them to roll during the day, they instead use a celestial body (the sun) as their primary orientation cue. Diurnal beetles, however, persist in using a celestial body for their compass, day or night. Compass neurons in the central complex of diurnal beetles are tuned only to the sun, whereas the same neurons in the nocturnal species switch exclusively to polarized light at lunar light intensities. Thus, these neurons encode the preferences for particular celestial cues and alter their weighting according to ambient light conditions. This flexible encoding of celestial cue preferences relative to the prevailing visual scenery provides a simple, yet effective, mechanism for enabling visual orientation at any light intensity. PMID:26305929

Neural coding underlying the cue preference for celestial orientation.

PubMed

el Jundi, Basil; Warrant, Eric J; Byrne, Marcus J; Khaldy, Lana; Baird, Emily; Smolka, Jochen; Dacke, Marie

2015-09-08

Diurnal and nocturnal African dung beetles use celestial cues, such as the sun, the moon, and the polarization pattern, to roll dung balls along straight paths across the savanna. Although nocturnal beetles move in the same manner through the same environment as their diurnal relatives, they do so when light conditions are at least 1 million-fold dimmer. Here, we show, for the first time to our knowledge, that the celestial cue preference differs between nocturnal and diurnal beetles in a manner that reflects their contrasting visual ecologies. We also demonstrate how these cue preferences are reflected in the activity of compass neurons in the brain. At night, polarized skylight is the dominant orientation cue for nocturnal beetles. However, if we coerce them to roll during the day, they instead use a celestial body (the sun) as their primary orientation cue. Diurnal beetles, however, persist in using a celestial body for their compass, day or night. Compass neurons in the central complex of diurnal beetles are tuned only to the sun, whereas the same neurons in the nocturnal species switch exclusively to polarized light at lunar light intensities. Thus, these neurons encode the preferences for particular celestial cues and alter their weighting according to ambient light conditions. This flexible encoding of celestial cue preferences relative to the prevailing visual scenery provides a simple, yet effective, mechanism for enabling visual orientation at any light intensity.

The Geomagnetic Field Is a Compass Cue in Cataglyphis Ant Navigation.

PubMed

Fleischmann, Pauline Nikola; Grob, Robin; Müller, Valentin Leander; Wehner, Rüdiger; Rössler, Wolfgang

2018-05-07

Desert ants (Cataglyphis) are famous insect navigators. During their foraging lives, the ants leave their underground colonies for long distances and return to their starting point with fair accuracy [1, 2]. Their incessantly running path integrator provides them with a continually updated home vector [3-5]. Directional input to their path integrator is provided by a visual compass based on celestial cues [6, 7]. However, as path integration is prone to cumulative errors, the ants additionally employ landmark guidance routines [8-11]. At the start of their foraging lives, they acquire the necessary landmark information by performing well-structured learning walks [12, 13], including turns about their vertical body axes [14]. When Cataglyphis noda performs these pirouettes, it always gazes at the nest entrance during the longest of several short stopping phases [14]. As the small nest entrance is not visible, the ants can adjust their gaze direction only by reading out their path integrator. However, recent experiments have shown that, for adjusting the goal-centered gaze directions during learning walks, skylight cues are not required [15]. A most promising remaining compass cue is the geomagnetic field, which is used for orientation in one way or the other by a variety of animal species [16-25]. Here, we show that the gaze directions during the look-back-to-the-nest behavior change in a predictable way to alterations of the horizontal component of the magnetic field. This is the first demonstration that, in insects, a geomagnetic compass cue is both necessary and sufficient for accomplishing a well-defined navigational task. Copyright © 2018 Elsevier Ltd. All rights reserved.

The onset of dynamical instability and chaos in navigation satellite orbits

NASA Astrophysics Data System (ADS)

Rosengren, Aaron Jay; Daquin, Jérôme; Alessi, Elisa Maria; Valsecchi, Giovanni B.; Rossi, Alessandro; Deleflie, Florent

2015-05-01

Orbital resonances are ubiquitous in the Solar System and are harbingers for the onset of dynamical instability and chaos. It has long been suspected that the Global Navigation Satellite Systems exist in a background of complex resonances and chaotic motion; yet, the precise dynamical character of these phenomena remains elusive. Here we will show that the same underlying physical mechanism, the overlapping of secular resonances, responsible for the eventual destabilization of Mercury and recently proposed to explain the orbital architecture of extrasolar planetary systems (Lithwick Y., Wu Y., 2014, PNAS; Batygin K., Morbidelli A., Holman M.J., 2015, ApJ) is at the heart of the orbital instabilities of seemingly more mundane celestial bodies---the Earth's navigation satellites. We will demonstrate that the occurrence and nature of the secular resonances driving these dynamics depend chiefly on one aspect of the Moon's perturbed motion, the regression of the line of nodes. This talk will present analytical models that accurately reflect the true nature of the resonant interactions, and will show how chaotic diffusion is mediated by the web-like structure of secular resonances. We will also present an atlas of FLI stability maps, showing the extent of the chaotic regions of the phase space, computed through a hierarchy of more realistic, and more complicated, models, and compare the chaotic zones in these charts with the analytical estimation of the width of the chaotic layers from the heuristic Chirikov resonance-overlap criterion. The obtained results have remarkable practical applications for space debris mitigation and for satellite technology, and are both of essential dynamical and theoretical importance, with broad implications for planetary science.

Position determination systems. [using orbital antenna scan of celestial bodies

NASA Technical Reports Server (NTRS)

Shores, P. W. (Inventor)

1976-01-01

A system for an orbital antenna, operated at a synchronous altitude, to scan an area of a celestial body is disclosed. The antenna means comprises modules which are operated by a steering signal in a repetitive function for providing a scanning beam over the area. The scanning covers the entire area in a pattern and the azimuth of the scanning beam is transmitted to a control station on the celestial body simultaneous with signals from an activated ground beacon on the celestial body. The azimuth of the control station relative to the antenna is known and the location of the ground beacon is readily determined from the azimuth determinations.

The Celestial Basis of Civilization

NASA Astrophysics Data System (ADS)

Masse, W. B.

Scholars have long puzzled over the reasons for the ubiquity of celestial images in the residue of the world's earliest civilizations: in art, myth, religious cosmology, iconography, cosmogony, eschatological beliefs, and as portents for the conduct of royal and chiefly power. The general consensus is that these images represented a need by early societies to use the fixed celestial heavens in order to regulate ritual and agricultural cycles, and to satisfy a psychological need by people to relate themselves to their surrounding Universe. Such explanations are facile and miss an important aspect of the celestial heavens. The fixed celestial heavens served as the back-drop for a large number of often spectacular temporary naked-eye visible celestial events which animated the night and sometimes the daytime sky, and which created an 'otherworld' for virtually all cultural groups. In this paper I present a model derived from the detailed analysis of Hawaiian oral traditions and culture history in relation to historic astronomical records of temporary celestial events, and then apply this model to cultural traditions from Mesoamerica and other geographic regions in order to demonstrate that novae, supernovae, variable stars, comets, great meteor showers, aurorae, solar and lunar eclipses, and impacting Solar System debris, together played a critical role in the artistic, intellectual, and political development of early civilizations. These data not only provide important insights into the development of civilization, but also provide important details and longitudinal records of astronomical events and phenomena which are otherwise not readily available for scientific scrutiny.

Do neotropical migrant butterflies navigate using a solar compass?

PubMed

Oliveira; Srygley; Dudley

1998-12-01

Many tropical butterfly species are well-known for their migratory behaviour. Although these insects can maintain a constant direction throughout the day, the physiological mechanisms of orientation are unknown. It has been argued that tropical migrant butterflies must use a time-compensated sun compass to accomplish their journey, but the crucial experimental manipulations to test this hypothesis have not been conducted. This study reports the results of clock-shift experiments performed with two species of migrating butterflies (Pieridae: Aphrissa statira and Phoebis argante) captured during flight across Lake Gatun, Panama. The observed constant flight bearing of natural controls suggests that these species are capable of performing time-compensated celestial navigation. Our clock-shift experiments suggest that a sun compass is involved. Individuals submitted to a 4 h advance shift took significantly different mean orientations on release compared with control butterflies. The direction of this difference was consistent with the use of a sun compass. The magnitude was approximately half the predicted value if the vanishing bearing of released butterflies was used as the variable to evaluate the effect of time-shifting and approximately three-quarters of that predicted if the estimated heading was the variable used. Mean vanishing bearings of control and experimental butterflies did not correspond to predicted values. This difference can be attributed largely to the combined effects of wind and handling.

The Solar system.Stars and constellations

NASA Astrophysics Data System (ADS)

Horia Minda, Octavian

2017-04-01

It is important for students to understand what is in our Solar System. The Students need to know that there are other things besides the Earth, Sun and Moon in the solar sky. The students will learn about the other eight planets and a few other celestial objects like stars and constellations. Constellations are useful because they can help people to recognize stars in the sky. By looking for patterns, the stars and locations can be much easier to spot. The constellations had uses in ancient times. They were used to help keep track of the calendar. This was very important so that people knew when to plant and harvest crops. Another important use for constellations was navigation. By finding Ursa Minor it is fairly easy to spot the North Star (Polaris). Using the height of the North Star in the sky, navigators could figure out their latitude helping ships to travel across the oceans. Objective: 1. The students will be introduced to the origin of the stars they see at night. 2. They will learn that there are groups of stars called constellations. The students will individually create their own constellations. They will be given the chance to tell the class a small story explaining their constellation. Evaluation of Children: The children will be evaluated through the creation of their constellations and ability to work in groups on the computers.

Simultaneous calibrations of Voyager celestial and inertial attitude control systems in flight

NASA Technical Reports Server (NTRS)

Jahanshahi, M. H.

1982-01-01

A mathematical description of the data reduction technique used to simultaneously calibrate the Voyager celestial and inertial attitude control subsystems is given. It is shown that knowledge of the spacecraft limit cycle motion, as measured by the celestial and the inertial sensors, is adequate to result in the estimates of a selected number of errors which adversely affect the spacecraft attitude knowledge.

Magnetic information affects the stellar orientation of young bird migrants

NASA Astrophysics Data System (ADS)

Weindler, Peter; Wiltschko, Roswitha; Wiltschko, Wolfgang

1996-09-01

WHEN young birds leave on their first migration, they are guided by innate information about their direction of migration. It is generally assumed that this direction is represented twice, namely with respect to celestial rotation and with respect to the Earth's magnetic field1,2. The interactions between the two cue systems have been analysed by exposing hand-raised young birds during the premigratory period to cue-conflict situations, in which celestial rotation and the magnetic field provided different information. Celestial rotation altered the course with respect to the magnetic field3-7, whereas conflicting magnetic information did not seem to affect the course with respect to the stars8,9. Celestial information thus seemed to dominate over magnetic information. Here we report that the interaction between the two cue systems is far more complex than this. Celestial rotation alone seems to provide only a tendency to move away from its centre (towards geographical south), which is then modified by information from the magnetic field to establish the distinctive, population-specific migratory direction.

The Second Realization of the International Celestial Reference Frame by Very Long Baseline Interferometry

NASA Astrophysics Data System (ADS)

Fey, A. L.; Gordon, D.; Jacobs, C. S.; Ma, C.; Gaume, R. A.; Arias, E. F.; Bianco, G.; Boboltz, D. A.; Böckmann, S.; Bolotin, S.; Charlot, P.; Collioud, A.; Engelhardt, G.; Gipson, J.; Gontier, A.-M.; Heinkelmann, R.; Kurdubov, S.; Lambert, S.; Lytvyn, S.; MacMillan, D. S.; Malkin, Z.; Nothnagel, A.; Ojha, R.; Skurikhina, E.; Sokolova, J.; Souchay, J.; Sovers, O. J.; Tesmer, V.; Titov, O.; Wang, G.; Zharov, V.

2015-08-01

We present the second realization of the International Celestial Reference Frame (ICRF2) at radio wavelengths using nearly 30 years of Very Long Baseline Interferometry observations. ICRF2 contains precise positions of 3414 compact radio astronomical objects and has a positional noise floor of ∼40 μas and a directional stability of the frame axes of ∼10 μas. A set of 295 new “defining” sources was selected on the basis of positional stability and the lack of extensive intrinsic source structure. The positional stability of these 295 defining sources and their more uniform sky distribution eliminates the two greatest weaknesses of the first realization of the International Celestial Reference Frame (ICRF1). Alignment of ICRF2 with the International Celestial Reference System was made using 138 positionally stable sources common to both ICRF2 and ICRF1. The resulting ICRF2 was adopted by the International Astronomical Union as the new fundamental celestial reference frame, replacing ICRF1 as of 2010 January 1.

Generation of dynamo waves by spatially separated sources in the Earth and other celestial bodies

NASA Astrophysics Data System (ADS)

Popova, E.

2017-12-01

The amplitude and the spatial configuration of the planetary and stellar magnetic field can changing over the years. Celestial bodies can have cyclic, chaotic or unchanging in time magnetic activity which is connected with a dynamo mechanism. This mechanism is based on the consideration of the joint influence of the alpha-effect and differential rotation. Dynamo sources can be located at different depths (active layers) of the celestial body and can have different intensities. Application of this concept allows us to get different forms of solutions and some of which can include wave propagating inside the celestial body. We analytically showed that in the case of spatially separated sources of magnetic field each source generates a wave whose frequency depends on the physical parameters of its source. We estimated parameters of sources required for the generation nondecaying waves. We discus structure of such sources and matter motion (including meridional circulation) in the liquid outer core of the Earth and active layers of other celestial bodies.

THE CELESTIAL REFERENCE FRAME AT 24 AND 43 GHz. II. IMAGING

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

Charlot, P.; Boboltz, D. A.; Fey, A. L.

2010-05-15

We have measured the submilliarcsecond structure of 274 extragalactic sources at 24 and 43 GHz in order to assess their astrometric suitability for use in a high-frequency celestial reference frame (CRF). Ten sessions of observations with the Very Long Baseline Array have been conducted over the course of {approx}5 years, with a total of 1339 images produced for the 274 sources. There are several quantities that can be used to characterize the impact of intrinsic source structure on astrometric observations including the source flux density, the flux density variability, the source structure index, the source compactness, and the compactness variability.more » A detailed analysis of these imaging quantities shows that (1) our selection of compact sources from 8.4 GHz catalogs yielded sources with flux densities, averaged over the sessions in which each source was observed, of about 1 Jy at both 24 and 43 GHz, (2) on average the source flux densities at 24 GHz varied by 20%-25% relative to their mean values, with variations in the session-to-session flux density scale being less than 10%, (3) sources were found to be more compact with less intrinsic structure at higher frequencies, and (4) variations of the core radio emission relative to the total flux density of the source are less than 8% on average at 24 GHz. We conclude that the reduction in the effects due to source structure gained by observing at higher frequencies will result in an improved CRF and a pool of high-quality fiducial reference points for use in spacecraft navigation over the next decade.« less

Integration of celestial compass cues in the central complex of the locust brain.

PubMed

Pegel, Uta; Pfeiffer, Keram; Homberg, Uwe

2018-01-29

Many insects rely on celestial compass cues such as the polarization pattern of the sky for spatial orientation. In the desert locust, the central complex (CX) houses multiple sets of neurons, sensitive to the oscillation plane of polarized light and thus probably acts as an internal polarization compass. We investigated whether other sky compass cues like direct sunlight or the chromatic gradient of the sky might contribute to this compass. We recorded from polarization-sensitive CX neurons while an unpolarized green or ultraviolet light spot was moved around the head of the animal. All types of neuron that were sensitive to the plane of polarization ( E -vector) above the animal also responded to the unpolarized light spots in an azimuth-dependent way. The tuning to the unpolarized light spots was independent of wavelength, suggesting that the neurons encode solar azimuth based on direct sunlight and not on the sky chromatic gradient. Two cell types represented the natural 90 deg relationship between solar azimuth and zenithal E -vector orientation, providing evidence to suggest that solar azimuth information supports the internal polarization compass. Most neurons showed advances in their tuning to the E -vector and the unpolarized light spots dependent on rotation direction, consistent with anticipatory signaling. The amplitude of responses and its variability were dependent on the level of background firing, possibly indicating different internal states. The integration of polarization and solar azimuth information strongly suggests that besides the polarization pattern of the sky, direct sunlight might be an important cue for sky compass navigation in the locust. © 2018. Published by The Company of Biologists Ltd.

Establishing a celestial VLBI reference frame. 1: Searching for VLBI sources

NASA Technical Reports Server (NTRS)

Preston, R. A.; Morabito, D. D.; Williams, J. G.; Slade, M. A.; Harris, A. W.; Finley, S. G.; Skjerve, L. J.; Tanida, L.; Spitzmesser, D. J.; Johnson, B.

1978-01-01

The Deep Space Network is currently engaged in establishing a new high-accuracy VLBI celestial reference frame. The present status of the task of finding suitable celestial radio sources for constructing this reference frame is discussed. To date, 564 VLBI sources were detected, with 166 of these lying within 10 deg of the ecliptic plane. The variation of the sky distribution of these sources with source strength is examined.

A Native Intelligence Metric for Artificial Systems

DTIC Science & Technology

2002-08-01

an example to help clarify the GCEA. Say we are S and we stumble upon Stonehenge . We don’t wonder whether humans carried the stones (some...stones S encounters that may be exhibiting alignment with celestial bodies at certain seasonal times. S determines that the designer of Stonehenge had...matching of the stones with particular celestial events. The various celestial events and our prehistoric Stonehenge designer’s awareness of these events

Astrometry for Astrophysics

NASA Astrophysics Data System (ADS)

van Altena, William F.

Part I. Astrometry in the Twenty-First Century: 1. Opportunities and challenges for astrometry in the twenty-first century M. Perryman; 2. Astrometric satellites L. Lindegren; 3. Ground-based opportunities for astrometry N. Zacharias; Part II. Relativistic Foundations of Astrometry and Celestial Mechanics: 4. Vectors in astrometry, an introduction L. Lindegren; 5. Relativistic principles of astrometry and celestial mechanics S. Klioner; 6. Celestial mechanics of the N-body problem S. Klioner; 7. Celestial coordinate systems and positions N. Capitaine and M. Stavinschi; 8. Fundamental algorithms for celestial coordinates and positions P. Wallace; Part III. Observing through the Atmosphere: 9. The Earth's atmosphere: refraction, turbulence, delays and limitations to astrometic precision W. van Altena and E. Fomalont; 10. Astrometry with ground-based diffraction-limited imaging A. Ghez; 11. Optical interferometry A. Glindermann; 12. Radio interferometry E. Fomalont; Part VI. From Detected Photons to the Celestial Sphere: 13. Geometrical optics and astrometry D. Schroeder; 14. CCD imaging detectors S. Howell; 15. Using CCDs in the time-delayed integration mode D. Rabinowitz; 16. Statistical astronomy A. Brown; 17. Analyzing poorly-sampled images: HST imaging astrometry J. Anderson; 18. Image deconvolution J. Nuñez; 19. From measures to celestial coordinates Z. H. Tang and W. van Altena; 20. Astrometric catalogs: concepts, history and necessity C. López; 21. Trigonometric parallaxes F. Benedict and B. McArthur; Part V. Applications of Astrometry to Topics in Astrophysics: 22. Galactic structure astrometry R. Méndez; 23. Binary and multiple stars E. Horch; 24. Binaries: HST, Hipparcos and Gaia D. Pourbaix; 25. Star clusters I. Platais; 26. Solar System astrometry F. Mignard; 27. Extrasolar planets A. Sozzetti; 28. Astrometric measurement and cosmology R. Easther; Appendices; Index.

Astrometry for Astrophysics

NASA Astrophysics Data System (ADS)

van Altena, William F.

2012-11-01

Part I. Astrometry in the Twenty-First Century: 1. Opportunities and challenges for astrometry in the twenty-first century M. Perryman; 2. Astrometric satellites L. Lindegren; 3. Ground-based opportunities for astrometry N. Zacharias; Part II. Relativistic Foundations of Astrometry and Celestial Mechanics: 4. Vectors in astrometry, an introduction L. Lindegren; 5. Relativistic principles of astrometry and celestial mechanics S. Klioner; 6. Celestial mechanics of the N-body problem S. Klioner; 7. Celestial coordinate systems and positions N. Capitaine and M. Stavinschi; 8. Fundamental algorithms for celestial coordinates and positions P. Wallace; Part III. Observing through the Atmosphere: 9. The Earth's atmosphere: refraction, turbulence, delays and limitations to astrometic precision W. van Altena and E. Fomalont; 10. Astrometry with ground-based diffraction-limited imaging A. Ghez; 11. Optical interferometry A. Glindermann; 12. Radio interferometry E. Fomalont; Part VI. From Detected Photons to the Celestial Sphere: 13. Geometrical optics and astrometry D. Schroeder; 14. CCD imaging detectors S. Howell; 15. Using CCDs in the time-delayed integration mode D. Rabinowitz; 16. StaStatistical astronomy A. Brown; 17. Analyzing poorly-sampled images: HST imaging astrometry J. Anderson; 18. Image deconvolution J. Nuñez; 19. From measures to celestial coordinates Z. H. Tang and W. van Altena; 20. Astrometric catalogs: concepts , history and necessity C. Löpez; 21. Trigonometric parallaxes F. Benedict and B. McArthur; Part V. Applications of Astrometry to Topics in Astrophysics: 22. Galactic structure astrometry R. Méndez; 23. Binary and multiple stars E. Horch; 24. Binaries: HST, Hipparcos and Gaia D. Pourbaix; 25. Star clusters I. Platais; 26. Solar System astrometry F. Mignard; 27. Extrasolar planets A. Sozzetti; 28. Astrometric measurement and cosmology R. Easther; Appendices; Index.

The significance of the Sun, Moon and celestial bodies to societies in the Carpathian basin during the Bronze Age

NASA Astrophysics Data System (ADS)

Pásztor, Emília

2011-06-01

Celestial events often exerted a great or even decisive influence on the life of ancient communities. They may provide some of the foundations on which an understanding of the deeper meaning of mythologies, religious systems and even folk tales can be based. These influences are reflected and may be detected in the archaeological material as well. There is good evidence that celestial (especially solar and perhaps lunar) phenomena played a particularly important rôle in the worldview of prehistoric Europe. To reveal the social and ideational significance of concepts relating to the celestial bodies in the prehistory of the Carpathian Basin, complex investigations on orientations of houses and graves, prestige archaeological finds and iconography have been accomplished. The results indicate ideological and/or social changes, which developed into a likely organized ideological system in large part of Central Europe including the Carpathian Basin by the Late Bronze Age. It might also be the first period in prehistory when people became really interested in celestial phenomena.

Terrestrial passage theory of the moon illusion.

PubMed

Reed, C F

1984-12-01

Theories of the celestial, or moon, illusion have neglected geometric characteristics of movement along and above the surface of the earth. The illusion occurs because the characteristics of terrestrial passage are attributed to celestial passage. In terrestrial passage, the visual angle subtended by an object changes discriminably as an essentially invariant function of elevation above the horizon. In celestial passage, by contrast, change in visual angle is indiscriminable at all elevations. If a terrestrial object gains altitude, its angular subtense fails to follow the expansion projected for an orbital course: Angular diminution or constancy is equivalent to distancing. On the basis of terrestrial projections, a similar failure of celestial objects in successive elevations is also equivalent to distancing. The illusion occurs because of retinal image constancy, not--as traditionally stated--despite it.

On the Astronomical Knowledge and Traditions of Aboriginal Australians

NASA Astrophysics Data System (ADS)

Hamacher, Duane W.

2011-12-01

Historian of science David Pingree defines science in a broad context as the process of systematically explaining perceived or imaginary phenomena. Although Westerners tend to think of science being restricted to Western culture, I argue in this thesis that astronomical scientific knowledge is found in Aboriginal traditions. Although research into the astronomical traditions of Aboriginal Australians stretches back for more than 150 years, it is relatively scant in the literature. We do know that the sun, moon, and night sky have been an important and inseparable component of the landscape to hundreds of Australian Aboriginal groups for thousands (perhaps tens-of-thousands) of years. The literature reveals that astronomical knowledge was used for time keeping, denoting seasonal change and the availability of food sources, navigation, and tidal prediction. It was also important for rituals and ceremonies, birth totems, marriage systems, cultural mnemonics, and folklore. Despite this, the field remains relatively unresearched considering the diversity of Aboriginal cultures and the length of time people have inhabited Australia (well over 40,000 years). Additionally, very little research investigating the nature and role of transient celestial phenomena has been conducted, leaving our understanding of Indigenous astronomical knowledge grossly incomplete. This thesis is an attempt to overcome this deficiency, with a specific focus on transient celestial phenomena. My research, situated in the field of cultural astronomy, draws from the sub-disciplines of archaeoastronomy, ethnoastronomy, historical astronomy, and geomythology. This approach incorporates the methodologies and theories of disciplines in the natural sciences, social sciences, and humanities. This thesis, by publication, makes use of archaeological, ethnographic, and historical records, astronomical software packages, and geographic programs to better understand the ages of astronomical traditions and the role and nature of eclipses, comets, meteors, impact events, and certain variable stars. I also test the hypothesis that certain types of stone arrangements have preferred orientations that probably relate to astronomical phenomena. This research shows that Aboriginal astronomical traditions explain the motions of celestial bodies and the relationship between events in the sky and events on Earth. I explore how Aboriginal people perceived and made use of particular astronomical phenomena, such as meteors and comets, and show that Aboriginal people made careful observations of the motions of celestial bodies. I provide evidence that Aboriginal people noticed the change in brightness of particular stars, described the kinematics of eclipses, explained how lunar phases are related to ocean tides, and acknowledged the relationship between meteors, meteorites, impact events, and impact craters. I then show that linear stone arrangements in New South Wales have a preferred orientation to the cardinal points and explore astronomical reasons for this. In the Appendix, I include biographical details of William Edward Stanbridge, one of the first people to write in depth about Aboriginal astronomical traditions, which were compiled from historic records.

The future of almanac services --- an HMNAO perspective

NASA Astrophysics Data System (ADS)

Bell, S.; Nelmes, S.; Prema, P.; Whittaker, J.

2015-08-01

This talk will explore the means for delivering almanac data currently under consideration by HM Nautical Almanac Office in the near to medium future. While there will be a need to continue printed almanacs, almanac data must be available in a variety of forms ranging from paper almanacs to traditional web services through to applications for mobile devices and smartphones. The supply of data using applications may call for a different philosophy in supplying ephemeris data, one that differentiates between an application that calls on a web server for its data and one that has built-in ephemerides. These ephemerides need to be of a reasonably high precision while maintaining a modest machine footprint. These services also need to provide a wide range of applications ranging from traditional sunrise/set data though to more specialized services such as celestial navigation. The work necessary to meet these goals involves efficient programming, intuitive user interfaces, compact and efficient ephemerides and a suitable range of tools to meet the user's needs.

Migrating songbirds tested in computer-controlled Emlen funnels use stellar cues for a time-independent compass.

PubMed

Mouritsen, H; Larsen, O N

2001-11-01

This paper investigates how young pied flycatchers, Ficedula hypoleuca, and blackcaps, Sylvia atricapilla, interpret and use celestial cues. In order to record these data, we developed a computer-controlled version of the Emlen funnel, which enabled us to make detailed temporal analyses. First, we showed that the birds use a star compass. Then, we tested the birds under a stationary planetarium sky, which simulated the star pattern of the local sky at 02:35 h for 11 consecutive hours of the night, and compared the birds' directional choices as a function of time with the predictions from five alternative stellar orientation hypotheses. The results supported the hypothesis suggesting that birds use a time-independent star compass based on learned geometrical star configurations to pinpoint the rotational point of the starry sky (north). In contrast, neither hypotheses suggesting that birds use the stars for establishing their global position and then perform true star navigation nor those suggesting the use of a time-compensated star compass were supported.

Reviving a neglected celestial underwater polarization compass for aquatic animals.

PubMed

Waterman, Talbot H

2006-02-01

Substantial in situ measurements on clear days in a variety of marine environments at depths in the water down to 200 m have demonstrated the ubiquitous daytime presence of sun-related e-vector (=plane of polarization) patterns. In most lines of sight the e-vectors tilt from horizontal towards the sun at angles equal to the apparent underwater refracted zenith angle of the sun. A maximum tilt-angle of approximately 48.5 degrees , is reached in horizontal lines of sight at 90 degrees to the sun's bearing (the plane of incidence). This tilt limit is set by Snell's window, when the sun is on the horizon. The biological literature since the 1980s has been pervaded with assumptions that daytime aquatic e-vectors are mainly horizontal. This review attempts to set the record straight concerning the potential use of underwater e-vectors as a visual compass and to reopen the field to productive research on aquatic animals' orientation and navigation.

On the origins of the modern star map

NASA Astrophysics Data System (ADS)

Blomberg, P.

During the last few years there have been some papers dealing with the astronomical knowledge of the Minoans on Crete around 2000 BC and also of later cultures on Crete and the surrounding Greekspeaking areas. These works not only deal with possible observation lines but also show that the Minoans had built structures that could be used for determining the time of the equinoxes and solstices, for developing stellar navigation as well as finding the seasons suitable for sailing and agriculture. There have also been some papers presenting an astronomical iconography seen in Minoan figurines and seals. This paper discusses these suggested symbols of celestial bodies and some uses of them. It is also shown that there are links between the Minoan-Mycenaean period and Hellenistic times, i.e. from the 3rd/2nd millennium BC down to around 200 BC. This leads to the hypothesis that the western map of constellations has its roots on Crete during the Minoan period around 2000BC.

KSC-98pc1155

NASA Image and Video Library

1998-09-22

KENNEDY SPACE CENTER, FLA. -- Workers in the Payload Hazardous Servicing Facility maneuver a solar panel and rack to be attached to Deep Space 1 (background). The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, Cape Canaveral Air Station, in October. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches

KSC-98pc1156

NASA Image and Video Library

1998-09-22

KENNEDY SPACE CENTER, FLA. -- Workers in the Payload Hazardous Servicing Facility check fittings for the solar panel (right) they are attaching to Deep Space 1, preparing it for flight in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, Cape Canaveral Air Station. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches

KSC-98pc1181

NASA Image and Video Library

1998-09-29

KENNEDY SPACE CENTER, FLA. -- In the Payload Hazardous Servicing Facility, Tom Shain, project manager on Deep Space 1, displays a CD containing 350,000 names of KSC workers that he will place in a pouch and insert inside the spacecraft. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, Cape Canaveral Air Station, in October. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches

Deep Space 1 Using its Ion Engine (Artist's Concept)

NASA Technical Reports Server (NTRS)

2003-01-01

NASA's New Millennium Deep Space 1 spacecraft approaching the comet 19P/Borrelly. With its primary mission to serve as a technology demonstrator--testing ion propulsion and 11 other advanced technologies--successfully completed in September 1999, Deep Space 1 is now headed for a risky, exciting rendezvous with Comet Borrelly. NASA extended the mission, taking advantage of the ion propulsion and other systems to target the daring encounter with the comet in September 2001. Once a sci-fi dream, the ion propulsion engine has powered the spacecraft for over 12,000 hours. Another onboard experiment includes software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. The first flight in NASA's New Millennium Program, Deep Space 1 was launched October 24, 1998 aboard a Boeing Delta 7326 rocket from Cape Canaveral Air Station, FL. Deep Space 1 successfully completed and exceeded its mission objectives in July 1999 and flew by a near-Earth asteroid, Braille (1992 KD), in September 1999.

Osculating Keplerian Elements for Highly Non-Keplerian Orbits

DTIC Science & Technology

2017-03-27

1.52133 2 McInnes, C. R., “The Existence and Stability of Families of Displacement Two-Body Orbits”, Celestial Mechanics and Dynamical Astronomy , Vol...j.actaastro.2011.08.012 5 Xu, M. and Xu, S., “Nonlinear dynamical analysis for displaced orbits above a planet”, Celestial Mechanics and Dynamical Astronomy ...Celestial Mechanics and Dynamical Astronomy , Vol. 110, No. 3, 2011, pp. 199-215. doi: 10.1007/s10569-011-9351-5 7 Macdonald, M., McKay, R. J., Vasile, M

The Celestial Vault: The Magic of Astrology

NASA Astrophysics Data System (ADS)

McGaha, J.

2004-11-01

Astrology is a "Geocentric System" that supports the "Astrological Principle". This principle, that human beings and their actions are influenced by the positions of celestial objects, is not objectively supported. The "planetary gods" found in the heavens provided order to help explain the chaotic events in life on earth. Is this why many people think their horoscopes are correct, with the "stars" taking credit? Do "celestial movements" foretell the future? What is the evidence for Astrology? The historical, psychological and physical foundations of astrology will be discussed.

The Hands of the Pleiades: The Celestial Clock in the Classical Arabic Poetry of Dhū al-Rumma

NASA Astrophysics Data System (ADS)

Adams, W. B.

2011-06-01

In the desert poetry of Dhū al-Rumma (d. 117 AH/735 CE), astronomical phenomena sometimes function as familiar celestial timepieces that indicate the poetic timeframe literally and accurately. The literary, lexical, floral and astronomical analyses of a selection from this poetry illustrate the role of the Pleiades star cluster as a celestial clock and illuminate the utility of naked-eye astronomy in interpreting Arabic poetry of the early Islamic period.

Students' development of astronomy concepts across time

NASA Astrophysics Data System (ADS)

Plummer, Julia Diane

2006-02-01

The National Science Education Standards (NRC, 1996) recommend that students understand the apparent patterns of motion of the sun, moon and stars visible by the end of early elementary school. However, little information exists on students' knowledge of apparent celestial motion or instruction in this area. The goals of this dissertation were to describe children's knowledge of apparent celestial motion across elementary and middle school, explore early elementary students' ability to learn these topics through planetarium instruction, and begin the development of a learning progression for these concepts, First, third, and eighth grade students (N=60) were interviewed using a planetarium-like setting that allowed the students to demonstrate their ideas both verbally and with their own motions on an artificial sky. Analysis of these interviews suggests that students are not making the types of observations of the sky necessary to learn apparent celestial motion and any instruction they may have received has not helped them reach an accurate understanding of most topics. Most students at each grade level could not accurately describe the patterns of motion. Though the older students were more accurate in most of their descriptions than the younger students, in several areas the eighth grade students showed no improvement over the third grade students. The use of kinesthetic learning techniques in a planetarium program was also explored as a method to improve understanding of celestial motion. Pre- and post-interviews were conducted with participants from seven classes of first and second grade students (N=63). Students showed significant improvement in all areas of apparent celestial motion covered by the planetarium program and surpassed the middle school students' understanding of these concepts in most areas. This suggests that students in early elementary school are capable of learning the accurate description of apparent celestial motion. The results demonstrate the value of both kinesthetic learning techniques and the rich visual environment of the planetarium for improved understanding of celestial motion. Based on the results of these studies, I developed a learning progression describing how children may progress through successively more complex ways of understanding apparent celestial motion across elementary grades.

Celestial Seasonings: Astronomy and Rock Art in the American Southwest

NASA Astrophysics Data System (ADS)

Krupp, E. C.

1994-12-01

Astronomical interpretations of prehistoric rock art have played a significant part in the development of modern archaeoastronomy since 1975, when interest was renewed in the possibility that the Crab supernova explosion of 1054 A.D. was represented in rock art of the American Southwest. (This hypothesis was actually first formulated in 1955.) In the last two decades, a variety of astronomical functions for rock art have been proposed and investigated. These include representation of specific historical celestial events, symbolic representation of elements of celestial myths, star maps, markers for astronomical observing stations markers for celestially tempered shrines, images intended to invoke and exploit cosmo-magical power, seasonally significant light-and-shadow displays. Examples of astronomical connotations in prehistoric rock art from the Southwest and California illustrate the necessity of understanding the culture in any attempt to understand its astronomy.

Fast Light Optical Gyroscopes

NASA Technical Reports Server (NTRS)

Smith, David D.

2015-01-01

Next-generation space missions are currently constrained by existing spacecraft navigation systems which are not fully autonomous. These systems suffer from accumulated dead-reckoning errors and must therefore rely on periodic corrections provided by supplementary technologies that depend on line-of-sight signals from Earth, satellites, or other celestial bodies for absolute attitude and position determination, which can be spoofed, incorrectly identified, occluded, obscured, attenuated, or insufficiently available. These dead-reckoning errors originate in the ring laser gyros themselves, which constitute inertial measurement units. Increasing the time for standalone spacecraft navigation therefore requires fundamental improvements in gyroscope technologies. One promising solution to enhance gyro sensitivity is to place an anomalous dispersion or fast light material inside the gyro cavity. The fast light essentially provides a positive feedback to the gyro response, resulting in a larger measured beat frequency for a given rotation rate as shown in figure 1. Game Changing Development has been investing in this idea through the Fast Light Optical Gyros (FLOG) project, a collaborative effort which began in FY 2013 between NASA Marshall Space Flight Center (MSFC), the U.S. Army Aviation and Missile Research, Development, and Engineering Center (AMRDEC), and Northwestern University. MSFC and AMRDEC are working on the development of a passive FLOG (PFLOG), while Northwestern is developing an active FLOG (AFLOG). The project has demonstrated new benchmarks in the state of the art for scale factor sensitivity enhancement. Recent results show cavity scale factor enhancements of approx.100 for passive cavities.

OPTICAL SPECTRA OF CANDIDATE SOUTHERN HEMISPHERE INTERNATIONAL CELESTIAL REFERENCE FRAME (ICRF) RADIO SOURCES

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

Titov, O.; Jauncey, D. L.; Johnston, H. M.

2011-11-15

We present the results of spectroscopic observations of the optical counterparts of 47 southern radio sources from the candidate International Celestial Reference Catalogue as part of a very long baseline interferometry (VLBI) program to strengthen the celestial reference frame, especially in the south. We made the observations with the 3.58 m European Southern Observatory New Technology Telescope. We obtained redshifts for 30 quasars and one radio galaxy, with a further seven objects being probable BL Lac objects with featureless spectra. Of the remainder, four were clear misidentifications with Galactic stars and five had low signal-to-noise spectra and could not bemore » classified. These results, in combination with new VLBI data of the radio sources with redshifts more than 2, add significantly to the existing data needed to refine the distribution of source proper motions over the celestial sphere.« less

A consistent time frame for Chaucer's Canterbury Pilgrimage

NASA Astrophysics Data System (ADS)

Kummerer, K. R.

2001-08-01

A consistent time frame for the pilgrimage that Geoffrey Chaucer describes in The Canterbury Tales can be established if the seven celestial assertions related to the journey mentioned in the text can be reconciled with each other and the date of April 18 that is also mentioned. Past attempts to establish such a consistency for all seven celestial assertions have not been successful. The analysis herein, however, indicates that in The Canterbury Tales Chaucer accurately describes the celestial conditions he observed in the April sky above the London(Canterbury region of England in the latter half of the fourteenth century. All seven celestial assertions are in agreement with each other and consistent with the April 18 date. The actual words of Chaucer indicate that the Canterbury journey began during the 'seson' he defines in the General Prologue and ends under the light of the full Moon on the night of April 18, 1391.

Dynamical configurations of celestial systems comprised of multiple irregular bodies

NASA Astrophysics Data System (ADS)

Jiang, Yu; Zhang, Yun; Baoyin, Hexi; Li, Junfeng

2016-09-01

This manuscript considers the main features of the nonlinear dynamics of multiple irregular celestial body systems. The gravitational potential, static electric potential, and magnetic potential are considered. Based on the three established potentials, we show that three conservative values exist for this system, including a Jacobi integral. The equilibrium conditions for the system are derived and their stability analyzed. The equilibrium conditions of a celestial system comprised of n irregular bodies are reduced to 12n - 9 equations. The dynamical results are applied to simulate the motion of multiple-asteroid systems. The simulation is useful for the study of the stability of multiple irregular celestial body systems and for the design of spacecraft orbits to triple-asteroid systems discovered in the solar system. The dynamical configurations of the five triple-asteroid systems 45 Eugenia, 87 Sylvia, 93 Minerva, 216 Kleopatra, and 136617 1994CC, and the six-body system 134340 Pluto are calculated and analyzed.

The Future of Past Skies: Historical Celestial Cartography at the Adler Planetarium

NASA Astrophysics Data System (ADS)

Raposo, Pedro M. P.

2018-01-01

The Adler Planetarium is home to a world-class collection of scientific instruments, rare books and works on paper. Since 2014, Adler staff has been digitizing a wide selection of items relating to celestial cartography, including: more than 236 rare books and atlases; 97 works on paper; globes and other artifacts, amounting to 58 objects; and approximately 3,750 Carte du Ciel prints. This work has been carried out under the auspices of the Celestial Cartography Digitization Project (CCDP), which is sponsored by the National Endowment for the Humanities. This poster presentation will include: 1) an update on the project; 2) a description of related resources and tools available to the research community; 3) examples of how the Adler Planetarium is integrating the history of celestial cartography with its public programs; 4) an overview of a prospective citizen science project involving the identification of constellations in historical atlases and charts.

Contemplation and Calculation: The Universe Discovered.

ERIC Educational Resources Information Center

Solovyov, Yury

1992-01-01

Discusses how early notions about celestial mechanics were restructured, one by one, involving the following concepts: the celestial sphere and its rotation; the spherical earth; planetary motion; and models for the solar system initiated by Eudoxus, Hipparchus, Ptolemy, and Copernicus. (JJK)

Celestial Pole Offsets: Conversion From (dX, dY) to (d(psi), d(epsilon). Version 3

DTIC Science & Technology

2005-05-01

observed angular offset of the celestial pole from its modelled position, expressed in terms of changes in ecliptic longitude and obliquity . These...the mean obliquity of the ecliptic of date (≈ J2000.0). As the celestial pole precesses farther from the ICRS Z-axis, two effects must be accounted for...to only a few significant digits. With dX ′ and dY ′ in hand we compute dψ = dX ′/ sin ² d² = dY ′ (8) where ² is the mean obliquity of the ecliptic

On the Origin of Rotation of a Celestial Body

NASA Astrophysics Data System (ADS)

Vujičić, V. A.

1988-03-01

The differential equations of the self-rotation of a celestial body have been evaluated. From an integral of these equations a formula for angular velocity of the celestial body was obtained. This formula after being applied to the rotation of the Sun and of the Earth gives, respectively, the following angular velocity ranges: 0.588×10-6<ω<18, 187×10-6 and 0.7533×10-5<ω<12,4266×10-5. These are up to three times narrower than those previously obtained by Savić and Kašanin [1].

Re-calibration of the magnetic compass in hand-raised European robins (Erithacus rubecula)

PubMed Central

Alert, Bianca; Michalik, Andreas; Thiele, Nadine; Bottesch, Michael; Mouritsen, Henrik

2015-01-01

Migratory birds can use a variety of environmental cues for orientation. A primary calibration between the celestial and magnetic compasses seems to be fundamental prior to a bird’s first autumn migration. Releasing hand-raised or rescued young birds back into the wild might therefore be a problem because they might not have established a functional orientation system during their first calendar year. Here, we test whether hand-raised European robins that did not develop any functional compass before or during their first autumn migration could relearn to orient if they were exposed to natural celestial cues during the subsequent winter and spring. When tested in the geomagnetic field without access to celestial cues, these birds could orient in their species-specific spring migratory direction. In contrast, control birds that were deprived of any natural celestial cues throughout remained unable to orient. Our experiments suggest that European robins are still capable of establishing a functional orientation system after their first autumn. Although the external reference remains speculative, most likely, natural celestial cues enabled our birds to calibrate their magnetic compass. Our data suggest that avian compass systems are more flexible than previously believed and have implications for the release of hand-reared migratory birds. PMID:26388258

The astronomy of Andean myth: The history of a cosmology

NASA Astrophysics Data System (ADS)

Sullivan, William F.

It is shown that Andean myth, on one level, represents a technical language recording astronomical observations of precession and, at the same time, an historical record of simultaneous social and celestial transformations. Topographic and architectural terms of Andean myth are interpreted as a metaphor for the organization of and locations on the celestial sphere. Via ethoastronomical date, mythical animals are identified as stars and placed on the celestial sphere according to their topographical location. Tested in the planetarium, these arrays generate cluster of dates - 200 B.C. and 650 A.D. Analysis of the names of Wiraqocha and Manco Capac indicates they represent Saturn and Jupiter and that their mythical meeting represents their conjunction in 650 A.D. The astronomy of Andean myth is then used as an historical tool to examine how the Andean priest-astronomers recorded the simultaneous creation of the avllu and of this distinctive astronomical system about 200 B.C. The idea that the agricultural avllu, with its double descent system stressing the importance of paternity, represents a transformation of society from an earlier matrilineal/horticultural era is examined in light of the sexual imagery employed in myth. Wiraqocha's androgyny and the division of the celestial sphere into male (ecliptic) and female (celestial equator = earth) are interpreted as cosmological validations of the new social structure.

The Outer Space Treaty

NASA Astrophysics Data System (ADS)

Johnson, Christopher Daniel

2018-01-01

Negotiated at the United Nations and in force since 1967, the Outer Space Treaty has been ratified by over 100 countries and is the most important and foundational source of space law. The treaty, whose full title is "Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, Including the Moon and Other Celestial Bodies," governs all of humankind's activities in outer space, including activities on other celestial bodies and many activities on Earth related to outer space. All space exploration and human spaceflight, planetary sciences, and commercial uses of space—such as the global telecommunications industry and the use of space technologies such as position, navigation, and timing (PNT), take place against the backdrop of the general regulatory framework established in the Outer Space Treaty. A treaty is an international legal instrument which balances rights and obligations between states, and exists as a kind of mutual contract of shared understandings, rights, and responsibilities between them. Negotiated and drafted during the Cold War era of heightened political tensions, the Outer Space Treaty is largely the product of efforts by the United States and the USSR to agree on certain minimum standards and obligations to govern their competition in "conquering" space. Additionally, the Outer Space Treaty is similar to other treaties, including treaties governing the high seas, international airspace, and the Antarctic, all of which govern the behavior of states outside of their national borders. The treaty is brief in nature and only contains 17 articles, and is not comprehensive in addressing and regulating every possible scenario. The negotiating states knew that the Outer Space Treaty could only establish certain foundational concepts such as freedom of access, state responsibility and liability, non-weaponization of space, the treatment of astronauts in distress, and the prohibition of non-appropriation of celestial bodies. Subsequent treaties were to refine these concepts, and national space legislation was to incorporate the treaty's rights and obligations at the national level. While the treaty is the cornerstone in the regulation of activities in outer space, today the emergence of new issues that were not contemplated at the time of its creation, such as small satellites and megaconstellations, satellite servicing missions, the problem of space debris and the possibility of space debris removal, and the use of lunar and asteroid resources, all stretch the coherence and continuing adequacy of the treaty, and may occasion the need for new governance frameworks.

The International Celestial Reference Frame (ICRF) and the Relationship Between Frames

NASA Technical Reports Server (NTRS)

Ma, Chopo

2000-01-01

The International Celestial Reference Frame (ICRF), a catalog of VLBI source positions, is now the basis for astrometry and geodesy. Its construction and extension/maintenance will be discussed as well as the relationship of the ICRF, ITRF, and EOP/nutation.

Celestial mechanics with geometric algebra

NASA Technical Reports Server (NTRS)

Hestenes, D.

1983-01-01

Geometric algebra is introduced as a general tool for Celestial Mechanics. A general method for handling finite rotations and rotational kinematics is presented. The constants of Kepler motion are derived and manipulated in a new way. A new spinor formulation of perturbation theory is developed.

Students' Development of Astronomy Concepts across Time

NASA Astrophysics Data System (ADS)

Plummer, Julia

Students in Grades 1, 3, and 8 (N = 60) were interviewed while using a planetarium-like setting that allowed the students to demonstrate their ideas about apparent celestial motion both verbally and with their own motions. Though the older students were generally more accurate in many conceptual areas compared with the younger students, in several areas, the eighth-grade students showed no improvement over the third-grade students. The use of kinesthetic learning techniques in a planetarium program was also explored as a method to improve understanding of celestial motion. Pre- and postinterviews were conducted with participants from seven classes of first- and second-grade students (N = 63). Students showed significant improvement in all areas of apparent celestial motion covered by the planetarium program and surpassed the middle school students' understanding of these concepts in most areas. Based on the results of these studies, a learning progression was developed describing how children may progress through successively more complex ways of understanding apparent celestial motion across elementary grades.

The astronomical data base and retrieval system at NASA

NASA Technical Reports Server (NTRS)

Mead, J. M.; Nagy, T. A.; Hill, R. S.; Warren, W. H., Jr.

1982-01-01

More than 250 machine-readable catalogs of stars and extended celestial objects are now available at the NASA/Goddard Space Flight Center (GSFC) as the result of over a decade of catalog acquisition, verification and documentation. Retrieval programs are described which permit the user to obtain from a remote terminal bibliographical listings for stars; to find all celestial objects from a given list that are within a defined angular separation from each object in another list; to plot celestial objects on overlays for sky survey plate areas; and to search selected catalogs for objects by criteria of position, identification number, magnitude or spectral type.

Background Oriented Schlieren Using Celestial Objects

NASA Technical Reports Server (NTRS)

Haering, Edward, A., Jr. (Inventor); Hill, Michael A (Inventor)

2017-01-01

The present invention is a system and method of visualizing fluid flow around an object, such as an aircraft or wind turbine, by aligning the object between an imaging system and a celestial object having a speckled background, taking images, and comparing those images to obtain fluid flow visualization.

Opportunities of Teaching Archaeoastronomy in Thailand

ERIC Educational Resources Information Center

Anantasook, Sakanan; Yuenyong, Chokchai; Coll, Richard K.

2015-01-01

Ancient cultures around the world systematically observed the sky and noticed the motions of celestial objects including the stars, Moon, Sun, and planets. Many structural symbolic patterns were built to perceive, visualize and understand the celestial phenomena. They have used this knowledge, archaeoastronomy, to survive, and as bases for…

A Super-Resolution Algorithm for Enhancement of FLASH LIDAR Data: Flight Test Results

NASA Technical Reports Server (NTRS)

Bulyshev, Alexander; Amzajerdian, Farzin; Roback, Eric; Reisse Robert

2014-01-01

This paper describes the results of a 3D super-resolution algorithm applied to the range data obtained from a recent Flash Lidar helicopter flight test. The flight test was conducted by the NASA's Autonomous Landing and Hazard Avoidance Technology (ALHAT) project over a simulated lunar terrain facility at NASA Kennedy Space Center. ALHAT is developing the technology for safe autonomous landing on the surface of celestial bodies: Moon, Mars, asteroids. One of the test objectives was to verify the ability of 3D super-resolution technique to generate high resolution digital elevation models (DEMs) and to determine time resolved relative positions and orientations of the vehicle. 3D super-resolution algorithm was developed earlier and tested in computational modeling, and laboratory experiments, and in a few dynamic experiments using a moving truck. Prior to the helicopter flight test campaign, a 100mX100m hazard field was constructed having most of the relevant extraterrestrial hazard: slopes, rocks, and craters with different sizes. Data were collected during the flight and then processed by the super-resolution code. The detailed DEM of the hazard field was constructed using independent measurement to be used for comparison. ALHAT navigation system data were used to verify abilities of super-resolution method to provide accurate relative navigation information. Namely, the 6 degree of freedom state vector of the instrument as a function of time was restored from super-resolution data. The results of comparisons show that the super-resolution method can construct high quality DEMs and allows for identifying hazards like rocks and craters within the accordance of ALHAT requirements.

A distinct layer of the medulla integrates sky compass signals in the brain of an insect.

PubMed

el Jundi, Basil; Pfeiffer, Keram; Homberg, Uwe

2011-01-01

Mass migration of desert locusts is a common phenomenon in North Africa and the Middle East but how these insects navigate is still poorly understood. Laboratory studies suggest that locusts are able to exploit the sky polarization pattern as a navigational cue. Like other insects locusts detect polarized light through a specialized dorsal rim area (DRA) of the eye. Polarization signals are transmitted through the optic lobe to the anterior optic tubercle (AOTu) and, finally, to the central complex in the brain. Whereas neurons of the AOTu integrate sky polarization and chromatic cues in a daytime dependent manner, the central complex holds a topographic representation of azimuthal directions suggesting a role as an internal sky compass. To understand further the integration of sky compass cues we studied polarization-sensitive (POL) neurons in the medulla that may be intercalated between DRA photoreceptors and AOTu neurons. Five types of POL-neuron were characterized and four of these in multiple recordings. All neurons had wide arborizations in medulla layer 4 and most, additionally, in the dorsal rim area of the medulla and in the accessory medulla, the presumed circadian clock. The neurons showed type-specific orientational tuning to zenithal polarized light and azimuth tuning to unpolarized green and UV light spots. In contrast to neurons of the AOTu, we found no evidence for color opponency and daytime dependent adjustment of sky compass signals. Therefore, medulla layer 4 is a distinct stage in the integration of sky compass signals that precedes the time-compensated integration of celestial cues in the AOTu.

A super-resolution algorithm for enhancement of flash lidar data: flight test results

NASA Astrophysics Data System (ADS)

Bulyshev, Alexander; Amzajerdian, Farzin; Roback, Eric; Reisse, Robert

2013-03-01

This paper describes the results of a 3D super-resolution algorithm applied to the range data obtained from a recent Flash Lidar helicopter flight test. The flight test was conducted by the NASA's Autonomous Landing and Hazard Avoidance Technology (ALHAT) project over a simulated lunar terrain facility at NASA Kennedy Space Center. ALHAT is developing the technology for safe autonomous landing on the surface of celestial bodies: Moon, Mars, asteroids. One of the test objectives was to verify the ability of 3D super-resolution technique to generate high resolution digital elevation models (DEMs) and to determine time resolved relative positions and orientations of the vehicle. 3D super-resolution algorithm was developed earlier and tested in computational modeling, and laboratory experiments, and in a few dynamic experiments using a moving truck. Prior to the helicopter flight test campaign, a 100mX100m hazard field was constructed having most of the relevant extraterrestrial hazard: slopes, rocks, and craters with different sizes. Data were collected during the flight and then processed by the super-resolution code. The detailed DEM of the hazard field was constructed using independent measurement to be used for comparison. ALHAT navigation system data were used to verify abilities of super-resolution method to provide accurate relative navigation information. Namely, the 6 degree of freedom state vector of the instrument as a function of time was restored from super-resolution data. The results of comparisons show that the super-resolution method can construct high quality DEMs and allows for identifying hazards like rocks and craters within the accordance of ALHAT requirements.

Spectral properties of identified polarized-light sensitive interneurons in the brain of the desert locust Schistocerca gregaria.

PubMed

Kinoshita, Michiyo; Pfeiffer, Keram; Homberg, Uwe

2007-04-01

Many migrating animals employ a celestial compass mechanism for spatial navigation. Behavioral experiments in bees and ants have shown that sun compass navigation may rely on the spectral gradient in the sky as well as on the pattern of sky polarization. While polarized-light sensitive interneurons (POL neurons) have been identified in the brain of several insect species, there are at present no data on the neural basis of coding the spectral gradient of the sky. In the present study we have analyzed the chromatic properties of two identified POL neurons in the brain of the desert locust. Both neurons, termed TuTu1 and LoTu1, arborize in the anterior optic tubercle and respond to unpolarized light as well as to polarized light. We show here that the polarized-light response of both types of neuron relies on blue-sensitive photoreceptors. Responses to unpolarized light depended on stimulus position and wavelength. Dorsal unpolarized blue light inhibited the neurons, while stimulation from the ipsilateral side resulted in opponent responses to UV light and green light. While LoTu1 was inhibited by UV light and was excited by green light, one subtype of TuTu1 was excited by UV and inhibited by green light. In LoTu1 the sensitivity to polarized light was at least 2 log units higher than the response to unpolarized light stimuli. Taken together, the spatial and chromatic properties of the neurons may be suited to signal azimuthal directions based on a combination of the spectral gradient and the polarization pattern of the sky.

A Distinct Layer of the Medulla Integrates Sky Compass Signals in the Brain of an Insect

PubMed Central

el Jundi, Basil; Pfeiffer, Keram; Homberg, Uwe

2011-01-01

Mass migration of desert locusts is a common phenomenon in North Africa and the Middle East but how these insects navigate is still poorly understood. Laboratory studies suggest that locusts are able to exploit the sky polarization pattern as a navigational cue. Like other insects locusts detect polarized light through a specialized dorsal rim area (DRA) of the eye. Polarization signals are transmitted through the optic lobe to the anterior optic tubercle (AOTu) and, finally, to the central complex in the brain. Whereas neurons of the AOTu integrate sky polarization and chromatic cues in a daytime dependent manner, the central complex holds a topographic representation of azimuthal directions suggesting a role as an internal sky compass. To understand further the integration of sky compass cues we studied polarization-sensitive (POL) neurons in the medulla that may be intercalated between DRA photoreceptors and AOTu neurons. Five types of POL-neuron were characterized and four of these in multiple recordings. All neurons had wide arborizations in medulla layer 4 and most, additionally, in the dorsal rim area of the medulla and in the accessory medulla, the presumed circadian clock. The neurons showed type-specific orientational tuning to zenithal polarized light and azimuth tuning to unpolarized green and UV light spots. In contrast to neurons of the AOTu, we found no evidence for color opponency and daytime dependent adjustment of sky compass signals. Therefore, medulla layer 4 is a distinct stage in the integration of sky compass signals that precedes the time-compensated integration of celestial cues in the AOTu. PMID:22114712

Perceptual Strategies of Pigeons to Detect a Rotational Centre—A Hint for Star Compass Learning?

PubMed Central

Helduser, Sascha; Mouritsen, Henrik; Güntürkün, Onur

2015-01-01

Birds can rely on a variety of cues for orientation during migration and homing. Celestial rotation provides the key information for the development of a functioning star and/or sun compass. This celestial compass seems to be the primary reference for calibrating the other orientation systems including the magnetic compass. Thus, detection of the celestial rotational axis is crucial for bird orientation. Here, we use operant conditioning to demonstrate that homing pigeons can principally learn to detect a rotational centre in a rotating dot pattern and we examine their behavioural response strategies in a series of experiments. Initially, most pigeons applied a strategy based on local stimulus information such as movement characteristics of single dots. One pigeon seemed to immediately ignore eccentric stationary dots. After special training, all pigeons could shift their attention to more global cues, which implies that pigeons can learn the concept of a rotational axis. In our experiments, the ability to precisely locate the rotational centre was strongly dependent on the rotational velocity of the dot pattern and it crashed at velocities that were still much faster than natural celestial rotation. We therefore suggest that the axis of the very slow, natural, celestial rotation could be perceived by birds through the movement itself, but that a time-delayed pattern comparison should also be considered as a very likely alternative strategy. PMID:25807499

KSC-07pd2429

NASA Image and Video Library

2007-09-11

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, the Dawn spacecraft is moved toward the opening above the Delta II rocket in the mobile service tower. Dawn will be mated with the Delta in preparation for launch. Dawn is scheduled for launch in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Photo credit: NASA/Jack Pfaller

KSC-07pd2401

NASA Image and Video Library

2007-09-10

KENNEDY SPACE CENTER, FLA. -- At Astrotech Space Operations in Titusville, Fla., workers move the platform with the Dawn spacecraft. They are preparing to install the transportation canister around Dawn for transfer to Launch Pad 17-B at Cape Canaveral Air Force Station (CCAFS). During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch via a Delta II rocket is scheduled in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. Photo credit: NASA/Jim Grossmann

KSC-07pd2578

NASA Image and Video Library

2007-09-26

KENNEDY SPACE CENTER, FLA. -- The Delta II rocket is revealed as the mobile service tower, or gantry (at right), is retracted on Launch Pad 17B at Cape Canaveral Air Force Station. Starting with a boost from this higher thrust version of the Delta II rocket, the Dawn spacecraft will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission during its nearly decade-long mission, Dawn will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field, and thus, bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch is targeted for Sept. 27 during a window that extends from 7:20 to 7:49 a.m. EDT. Photo credit: NASA/Kim Shiflett

KSC-07pd2582

NASA Image and Video Library

2007-09-26

KENNEDY SPACE CENTER, FLA. -- Rollback of the mobile service tower, or gantry, from the Delta II rocket is complete on Launch Pad 17B at Cape Canaveral Air Force Station. Starting with a boost from this higher thrust version of the Delta II rocket, the Dawn spacecraft will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission during its nearly decade-long mission, Dawn will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field, and thus, bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch is targeted for Sept. 27 during a window that extends from 7:20 to 7:49 a.m. EDT. Photo credit: NASA/Kim Shiflett

KSC-07pd2408

NASA Image and Video Library

2007-09-10

KENNEDY SPACE CENTER, FLA. -- At Astrotech Space Operations in Titusville, Fla., workers ensure the upper transportation canister is securely attached to the lower segments. The canister will protect the spacecraft and booster during transfer to Launch Pad 17-B at Cape Canaveral Air Force Station (CCAFS). During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch via a Delta II rocket is scheduled in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. Photo credit: NASA/Jim Grossmann

KSC-07pd2430

NASA Image and Video Library

2007-09-11

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, the Dawn spacecraft is lowered toward the awaiting Delta II rocket in the mobile service tower. Dawn will be mated with the Delta in preparation for launch. Dawn is scheduled for launch in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Photo credit: NASA/Jack Pfaller

KSC-07pd2427

NASA Image and Video Library

2007-09-11

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, the Dawn spacecraft is lifted alongside the mobile service tower. At the top, Dawn will be prepared for mating with the awaiting Delta II rocket. Dawn is scheduled for launch in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Photo credit: NASA/Jack Pfaller

KSC-07pd2579

NASA Image and Video Library

2007-09-26

KENNEDY SPACE CENTER, FLA. -- A worker monitors the progress of the retraction of the mobile service tower, or gantry, from the Delta II rocket on Launch Pad 17B at Cape Canaveral Air Force Station. Starting with a boost from this higher thrust version of the Delta II rocket, the Dawn spacecraft will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission during its nearly decade-long mission, Dawn will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field, and thus, bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch is targeted for Sept. 27 during a window that extends from 7:20 to 7:49 a.m. EDT. Photo credit: NASA/Kim Shiflett

KSC-07pd2431

NASA Image and Video Library

2007-09-11

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, workers in the mobile service tower keep watch as the Dawn spacecraft is lowered toward the awaiting Delta II rocket. Dawn will be mated with the Delta in preparation for launch. Dawn is scheduled for launch in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Photo credit: NASA/Jack Pfaller

KSC-07pd2438

NASA Image and Video Library

2007-09-11

KENNEDY SPACE CENTER, FLA. -- In the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station, workers remove the transportation canister from around the Dawn spacecraft. After removal of the canister, Dawn will be mated with the waiting Delta II rocket. Dawn is scheduled for launch in a window from 7:25 to 7:54 a.m. EDT Sept. 26 from CCAFS. During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Photo credit: NASA/Jim Grossmann

KSC-07pd2426

NASA Image and Video Library

2007-09-11

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, the Dawn spacecraft is lifted alongside the mobile service tower. At the top, Dawn will be prepared for mating with the awaiting Delta II rocket. Dawn is scheduled for launch in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Photo credit: NASA/Jack Pfaller

KSC-07pd2445

NASA Image and Video Library

2007-09-11

KENNEDY SPACE CENTER, FLA. -- In the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station, the Dawn spacecraft is ready for mating with the waiting Delta II rocket. Dawn is scheduled for launch in a window from 7:25 to 7:54 a.m. EDT Sept. 26 from CCAFS. During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Photo credit: NASA/Jim Grossmann

KSC-07pd2581

NASA Image and Video Library

2007-09-26

KENNEDY SPACE CENTER, FLA. -- The Delta II rocket stands ready for launch following rollback of the mobile service tower, or gantry, on Launch Pad 17B at Cape Canaveral Air Force Station. Starting with a boost from this higher thrust version of the Delta II rocket, the Dawn spacecraft will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission during its nearly decade-long mission, Dawn will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field, and thus, bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch is targeted for Sept. 27 during a window that extends from 7:20 to 7:49 a.m. EDT. Photo credit: NASA/Kim Shiflett

KSC-07pd2580

NASA Image and Video Library

2007-09-26

KENNEDY SPACE CENTER, FLA. -- The Delta II rocket stands ready for launch following rollback of the mobile service tower, or gantry, on Launch Pad 17B at Cape Canaveral Air Force Station. Starting with a boost from this higher thrust version of the Delta II rocket, the Dawn spacecraft will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission during its nearly decade-long mission, Dawn will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field, and thus, bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch is targeted for Sept. 27 during a window that extends from 7:20 to 7:49 a.m. EDT. Photo credit: NASA/Kim Shiflett

KSC-07pd2428

NASA Image and Video Library

2007-09-11

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, the Dawn spacecraft arrives at the upper level of the mobile service tower. It will be moved inside and prepared for mating with the awaiting Delta II rocket. Dawn is scheduled for launch in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Photo credit: NASA/Jack Pfaller

KSC-07pd2424

NASA Image and Video Library

2007-09-11

KENNEDY SPACE CENTER, FLA. -- The Dawn spacecraft arrives on Launch Pad 17-B at Cape Canaveral Air Force Station. At the pad, Dawn will be lifted into the mobile service tower and prepared for mating with the awaiting Delta II rocket. Dawn is scheduled for launch in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Photo credit: NASA/Jack Pfaller

KSC-07pd2577

NASA Image and Video Library

2007-09-26

KENNEDY SPACE CENTER, FLA. -- The Delta II rocket is revealed as the mobile service tower, or gantry (at left), is retracted on Launch Pad 17B at Cape Canaveral Air Force Station. Starting with a boost from this higher thrust version of the Delta II rocket, the Dawn spacecraft will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission during its nearly decade-long mission, Dawn will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field, and thus, bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch is targeted for Sept. 27 during a window that extends from 7:20 to 7:49 a.m. EDT. Photo credit: NASA/Kim Shiflett

NICER Mission Overview, Status, and GO opportunities

NASA Astrophysics Data System (ADS)

Gendreau, Keith C.

2018-01-01

The Neutron Interior Composition Explorer (NICER) was launched in June 2017 to the International Space Station (ISS) where it is studying the time-domain X-ray sky. NICER consists of a collection of X-ray concentrators, silicon drift detectors, an optical bench, and pointing system that together provide a large collection area in the soft (0.2-12 keV) X-ray bandpass. NICER time-stamps individual X-ray photons to an absolute precision of better than 100 nanoseconds while providing moderate CCD-like energy resolution. Since installation, NICER has observed over 100 celestial targets including neutron stars and other objects. The NICER team accepts target of opportunity (TOO) requests for consideration. In addition, NICER will be demonstrating the use of some millisecond pulsars as navigational beacons. NICER will complete its baseline mission in January 2019 with data beginning to be made public in January 2018. Conditional on the status of its baseline science objectives, NICER will be open to a guest observer program with first round proposals due in mid 2018 for observations beginning in 2019.

KSC-07pd2442

NASA Image and Video Library

2007-09-11

KENNEDY SPACE CENTER, FLA. -- In the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station, the upper transportation canister is lifted away from the Dawn spacecraft. After removal of the canister, Dawn will be mated with the waiting Delta II rocket. Dawn is scheduled for launch in a window from 7:25 to 7:54 a.m. EDT Sept. 26 from CCAFS. During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Photo credit: NASA/Jim Grossmann

Use of local cues in the night-time navigation of the wandering desert spider Leucorchestris arenicola (Araneae, Sparassidae).

PubMed

Nørgaard, Thomas; Henschel, Joh R; Wehner, Rüdiger

2007-02-01

Adult male Leucorchestris arenicola can walk round-trips of several tens of meters in search of females. Most excursions end with the spiders returning to their burrow. For small animals homing over distances of several meters is theoretically impossible without the aid of external cues. It was investigated, whether the spiders use local cues or they rely solely on global cues. Individually marked male spiders were captured during their excursions and displaced several meters inside an opaque box. Ten out of twelve displaced spiders returned to their burrows. This shows that the male L. arenicola are using local cues during their homing, as the comparatively small displacement distances could not be detected by means of global, e.g. celestial cues. In order to test whether the spiders could be using olfactory guidance, the burrows were displaced by 2 m while the spiders were out on their journeys. In 12 out of 15 experiments, the spiders did not find their burrows. These results show that the burrows do not function as olfactory beacons for the homing spiders.

Conceptual approaches to avian navigation systems.

PubMed

Wallraff, H G

1991-01-01

The general basis of migratory orientation in birds is most probably an endogenous time-and-direction programme. Directions are selected with respect to celestial as well as geomagnetic clues. These clues appear to be integrated within a system that profits from the special advantages of either kind of environmental signal, and thereby can cope with their limitations. Using these clues, and following a genetically determined intended direction (or sequence of directions) over a genetically determined period of time, a bird may reach a larger population-specific area. However, it will hardly be able to find a particular location, such as, for instance, its previous breeding site. Homing to a familiar site over several hundred kilometers of unfamiliar terrain is substantially based on the smelling of atmospheric trace compounds. At shorter distances from home, orientation by means of--presumably visual--familiar landmarks completes the repertoire of mechanisms guiding a bird back home. These mechanisms are considered to be based on different kinds of 'maps' and 'compasses'. Conceptual approaches to the properties of an 'olfactory map' have as yet only reached an early state of speculation.

KSC-07pd2425

NASA Image and Video Library

2007-09-11

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, the Dawn spacecraft is lifted off its transporter. Dawn will be lifted into the mobile service tower and prepared for mating with the awaiting Delta II rocket.Dawn is scheduled for launch in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Photo credit: NASA/Jack Pfaller

KSC-98pc1194

NASA Image and Video Library

1998-10-01

Workers at this clean room facility, Cape Canaveral Air Station, prepare to lift the protective can that covered Deep Space 1 during transportation from KSC. The spacecraft will undergo spin testing at the site. Deep Space 1, the first flight in NASA's New Millennium Program, is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include a solar-powered ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. The ion propulsion engine is the first non-chemical propulsion to be used as the primary means of propelling a spacecraft. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. The spacecraft will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, Cape Canaveral Air Station, in October. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches

KSC-98pc1192

NASA Image and Video Library

1998-09-30

KENNEDY SPACE CENTER, FLA. -- Deep Space 1 is lifted from its work platform, giving a closeup view of the experimental solar-powered ion propulsion engine. The ion propulsion engine is the first non-chemical propulsion to be used as the primary means of propelling a spacecraft. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Another onboard experiment includes software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, Cape Canaveral Air Station, in October. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches

Deep Space 1 Ion Engine

NASA Image and Video Library

2002-12-21

Kennedy Space Center, Florida. - Deep Space 1 is lifted from its work platform, giving a closeup view of the experimental solar-powered ion propulsion engine. The ion propulsion engine is the first non-chemical propulsion to be used as the primary means of propelling a spacecraft. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Another onboard experiment includes software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, Cape Canaveral Air Station, in October. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches. http://photojournal.jpl.nasa.gov/catalog/PIA04232

Spatial integration in polarization-sensitive interneurones of crickets: a survey of evidence, mechanisms and benefits.

PubMed

Labhart, T; Petzold, J; Helbling, H

2001-07-01

Many insects exploit the polarization pattern of the sky for compass orientation in navigation or cruising-course control. Polarization-sensitive neurones (POL1-neurones) in the polarization vision pathway of the cricket visual system have wide visual fields of approximately 60 degrees diameter, i.e. these neurones integrate information over a large area of the sky. This results from two different mechanisms. (i) Optical integration; polarization vision is mediated by a group of specialized ommatidia at the dorsal rim of the eye. These ommatidia lack screening pigment, contain a wide rhabdom and have poor lens optics. As a result, the angular sensitivity of the polarization-sensitive photoreceptors is very wide (median approximately 20 degrees ). (ii) Neural integration; each POL1-neurone receives input from a large number of dorsal rim photoreceptors with diverging optical axes. Spatial integration in POL1-neurones acts as a spatial low-pass filter. It improves the quality of the celestial polarization signal by filtering out cloud-induced local disturbances in the polarization pattern and increases sensitivity.

The goldstone real-time connected element interferometer

NASA Technical Reports Server (NTRS)

Edwards, C., Jr.; Rogstad, D.; Fort, D.; White, L.; Iijima, B.

1992-01-01

Connected element interferometry (CEI) is a technique of observing a celestial radio source at two spatially separated antennas and then interfering the received signals to extract the relative phase of the signal at the two antennas. The high precision of the resulting phase delay data type can provide an accurate determination of the angular position of the radio source relative to the baseline vector between the two stations. This article describes a recently developed connected element interferometer on a 21-km baseline between two antennas at the Deep Space Network's Goldstone, California, tracking complex. Fiber-optic links are used to transmit the data to a common site for processing. The system incorporates a real-time correlator to process these data in real time. The architecture of the system is described, and observational data are presented to characterize the potential performance of such a system. The real-time processing capability offers potential advantages in terms of increased reliability and improved delivery of navigational data for time-critical operations. Angular accuracies of 50-100 nrad are achievable on this baseline.

KSC-98pc1334

NASA Image and Video Library

1998-10-12

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17A at Cape Canaveral Air Station, Deep Space 1 is viewed from above after installation on a Boeing Delta 7326 rocket . Targeted for launch on Oct. 25, Deep Space 1 is the first flight in NASA's New Millennium Program, and is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1116

NASA Image and Video Library

1998-09-17

A booster is raised off a truck bed and prepared for lifting to the Boeing Delta 7326 rocket that will launch Deep Space 1 at Launch Pad 17A, Cape Canaveral Air Station. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches. The Delta 7236 has three solid rocket boosters and a Star 37 upper stage. Delta IIs are manufactured in Huntington Beach, Calif. Rocketdyne, a division of The Boeing Company, builds Delta II's main engine in Canoga Park, Calif. Deep Space 1, the first flight in NASA's New Millennium Program, is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1111

NASA Image and Video Library

1998-09-17

A booster is lifted for installation onto the Boeing Delta 7326 rocket that will launch Deep Space 1 at Launch Pad 17A, Cape Canaveral Air Station. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches. The Delta 7236 has three solid rocket boosters and a Star 37 upper stage. Delta IIs are manufactured in Huntington Beach, Calif. Rocketdyne, a division of The Boeing Company, builds Delta II's main engine in Canoga Park, Calif. Deep Space 1, the first flight in NASA's New Millennium Program, is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1177

NASA Image and Video Library

1998-09-29

KENNEDY SPACE CENTER, FLA. -- In the Payload Hazardous Servicing Facility, the media (below), dressed in "bunny" suits, learn about Deep Space 1 from Leslie Livesay (facing cameras), Deep Space 1 spacecraft manager from the Jet Propulsion Laboratory. In the background, KSC workers place insulating blankets on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, Cape Canaveral Air Station, in October. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches

Deep Space 1 Using its Ion Engine Artist Concept

NASA Image and Video Library

2003-07-02

NASA's New Millennium Deep Space 1 spacecraft approaching the comet 19P/Borrelly. With its primary mission to serve as a technology demonstrator--testing ion propulsion and 11 other advanced technologies--successfully completed in September 1999, Deep Space 1 is now headed for a risky, exciting rendezvous with Comet Borrelly. NASA extended the mission, taking advantage of the ion propulsion and other systems to target the daring encounter with the comet in September 2001. Once a sci-fi dream, the ion propulsion engine has powered the spacecraft for over 12,000 hours. Another onboard experiment includes software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. The first flight in NASA's New Millennium Program, Deep Space 1 was launched October 24, 1998 aboard a Boeing Delta 7326 rocket from Cape Canaveral Air Station, FL. Deep Space 1 successfully completed and exceeded its mission objectives in July 1999 and flew by a near-Earth asteroid, Braille (1992 KD), in September 1999. http://photojournal.jpl.nasa.gov/catalog/PIA04604

KSC-98pc1119

NASA Image and Video Library

1998-09-17

Three boosters are lifted into place at Launch Pad 17A, Cape Canaveral Air Station, for installation onto the Boeing Delta 7326 rocket that will launch Deep Space 1. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches. The Delta 7236 has three solid rocket boosters and a Star 37 upper stage. Delta IIs are manufactured in Huntington Beach, Calif. Rocketdyne, a division of The Boeing Company, builds Delta II's main engine in Canoga Park, Calif. Deep Space 1, the first flight in NASA's New Millennium Program, is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1354

NASA Image and Video Library

1998-10-16

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17A at Cape Canaveral Air Station, workers maneuver the second half of the fairing to encapsulate Deep Space 1, targeted for launch aboard a Boeing Delta II rocket on Oct. 24. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1117

NASA Image and Video Library

1998-09-17

A booster is lifted off a truck for installation onto the Boeing Delta 7326 rocket that will launch Deep Space 1 at Launch Pad 17A, Cape Canaveral Air Station. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches. The Delta 7236 has three solid rocket boosters and a Star 37 upper stage. Delta IIs are manufactured in Huntington Beach, Calif. Rocketdyne, a division of The Boeing Company, builds Delta II's main engine in Canoga Park, Calif. Deep Space 1, the first flight in NASA's New Millennium Program, is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1118

NASA Image and Video Library

1998-09-17

Two boosters are lifted into place, while a third waits on the ground, for installation onto the Boeing Delta 7326 rocket that will launch Deep Space 1 at Launch Pad 17A, Cape Canaveral Air Station. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches. The Delta 7236 has three solid rocket boosters and a Star 37 upper stage. Delta IIs are manufactured in Huntington Beach, Calif. Rocketdyne, a division of The Boeing Company, builds Delta II's main engine in Canoga Park, Calif. Deep Space 1, the first flight in NASA's New Millennium Program, is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

Inertial Pointing and Positioning System

NASA Technical Reports Server (NTRS)

Yee, Robert (Inventor); Robbins, Fred (Inventor)

1998-01-01

An inertial pointing and control system and method for pointing to a designated target with known coordinates from a platform to provide accurate position, steering, and command information. The system continuously receives GPS signals and corrects Inertial Navigation System (INS) dead reckoning or drift errors. An INS is mounted directly on a pointing instrument rather than in a remote location on the platform for-monitoring the terrestrial position and instrument attitude. and for pointing the instrument at designated celestial targets or ground based landmarks. As a result. the pointing instrument and die INS move independently in inertial space from the platform since the INS is decoupled from the platform. Another important characteristic of the present system is that selected INS measurements are combined with predefined coordinate transformation equations and control logic algorithms under computer control in order to generate inertial pointing commands to the pointing instrument. More specifically. the computer calculates the desired instrument angles (Phi, Theta. Psi). which are then compared to the Euler angles measured by the instrument- mounted INS. and forms the pointing command error angles as a result of the compared difference.

KSC-98pc1335

NASA Image and Video Library

1998-10-12

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17A at Cape Canaveral Air Station, Deep Space 1 is uncovered after installation on a Boeing Delta 7326 rocket. Targeted for launch on Oct. 25, Deep Space 1 is the first flight in NASA's New Millennium Program, and is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1355

NASA Image and Video Library

1998-10-16

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17A at Cape Canaveral Air Station, workers check make a final check of the fairing encapsulating Deep Space 1, which is targeted for launch aboard a Boeing Delta II rocket on Oct. 24. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1331

NASA Image and Video Library

1998-10-12

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17A at Cape Canaveral Air Station, Deep Space 1 is lowered in the white room for installation on a Boeing Delta 7326 rocket . The spacecraft is targeted for launch on Oct. 25. Deep Space 1 is the first flight in NASA's New Millennium Program, and is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1333

NASA Image and Video Library

1998-10-12

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17A at Cape Canaveral Air Station, workers remove the transportation canister around Deep Space 1 after installation on a Boeing Delta 7326 rocket . Targeted for launch on Oct. 25, Deep Space 1 is the first flight in NASA's New Millennium Program, and is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1346

NASA Image and Video Library

1998-10-16

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17A at Cape Canaveral Air Station, workers begin encapsulating Deep Space 1 with the fairing (right side). Targeted for launch aboard a Boeing Delta 7326 rocket on Oct. 25, Deep Space 1 is the first flight in NASA's New Millennium Program, and is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

Consistent realization of Celestial and Terrestrial Reference Frames

NASA Astrophysics Data System (ADS)

Kwak, Younghee; Bloßfeld, Mathis; Schmid, Ralf; Angermann, Detlef; Gerstl, Michael; Seitz, Manuela

2018-03-01

The Celestial Reference System (CRS) is currently realized only by Very Long Baseline Interferometry (VLBI) because it is the space geodetic technique that enables observations in that frame. In contrast, the Terrestrial Reference System (TRS) is realized by means of the combination of four space geodetic techniques: Global Navigation Satellite System (GNSS), VLBI, Satellite Laser Ranging (SLR), and Doppler Orbitography and Radiopositioning Integrated by Satellite. The Earth orientation parameters (EOP) are the link between the two types of systems, CRS and TRS. The EOP series of the International Earth Rotation and Reference Systems Service were combined of specifically selected series from various analysis centers. Other EOP series were generated by a simultaneous estimation together with the TRF while the CRF was fixed. Those computation approaches entail inherent inconsistencies between TRF, EOP, and CRF, also because the input data sets are different. A combined normal equation (NEQ) system, which consists of all the parameters, i.e., TRF, EOP, and CRF, would overcome such an inconsistency. In this paper, we simultaneously estimate TRF, EOP, and CRF from an inter-technique combined NEQ using the latest GNSS, VLBI, and SLR data (2005-2015). The results show that the selection of local ties is most critical to the TRF. The combination of pole coordinates is beneficial for the CRF, whereas the combination of Δ UT1 results in clear rotations of the estimated CRF. However, the standard deviations of the EOP and the CRF improve by the inter-technique combination which indicates the benefits of a common estimation of all parameters. It became evident that the common determination of TRF, EOP, and CRF systematically influences future ICRF computations at the level of several μas. Moreover, the CRF is influenced by up to 50 μas if the station coordinates and EOP are dominated by the satellite techniques.

Inquiry and Astronomy: Preservice Teachers' Investigations of Celestial Motion

ERIC Educational Resources Information Center

Plummer, Julia D.; Zahm, Valerie M.; Rice, Rebecca

2010-01-01

This study investigated the impact of an open inquiry experience on elementary science methods students' understanding of celestial motion as well as the methods developed by students to answer their own research questions. Pre/post interviews and assessments were used to measure change in participants' understanding (N = 18). A qualitative…

Laplacean Ideology for Preliminary Orbit Determination and Moving Celestial Body Identification in Virtual Epoch

NASA Astrophysics Data System (ADS)

Bykov, O. P.

Any CCD frames with stars or galaxies or clusters and other images must be studied for a searching of moving celestial objects, namely asteroids, comets, artificial Earth satellites inside them. At Pulkovo Astronomical Observatory, new methods and software were elaborated to solve this problem.

The Mathematics of Go to Telescopes

ERIC Educational Resources Information Center

Teets, Donald

2007-01-01

This article presents the mathematics involved in finding and tracking celestial objects with an electronically controlled telescope. The essential idea in solving this problem is to choose several different coordinate systems that simplify the various motions of the earth and other celestial objects. These coordinate systems are then related by…

Solar system lithograph set for earth and space science

NASA Technical Reports Server (NTRS)

1995-01-01

A color lithographs of many of the celestial bodies within our solar system are contained in this educational set of materials. Printed on the back of each lithograph is information regarding the particular celestial body. A sheet with information listing NASA resources and electronic resources for education is included.

Did a Comet Deliver the Chelyabinsk Meteorite?

NASA Astrophysics Data System (ADS)

Gladysheva, O. G.

2017-09-01

An explosion of a celestial body occurred on the fifteenth of February, 2013, near Chelyabinsk (Russia). The explosive energy was determined as 500 kt of TNT, on the basis of which the mass of the bolide was estimated at 107 kg, and its diameter at 19 m [1]. Fragments of the meteorite, such as LL5/S4-WO type ordinary chondrite [2] with a total mass only of 2•103 kg, fell to the earth's surface [3]. Here, we will demonstrate that the deficit of the celestial body's mass can be explained by the arrival of the Chelyabinsk chondrite on Earth by a significantly more massive but fragile ice-bearing celestial body.

UBVRI PHOTOMETRIC STANDARD STARS AROUND THE CELESTIAL EQUATOR: UPDATES AND ADDITIONS

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

Landolt, Arlo U.

2009-05-15

New broadband UBVRI photoelectric observations on the Johnson-Kron-Cousins photometric system have been made of 202 stars around the sky, and centered at the celestial equator. These stars constitute both an update of and additions to a previously published list of equatorial photometric standard stars. The list is capable of providing, for both celestial hemispheres, an internally consistent homogeneous broadband standard photometric system around the sky. When these new measurements are included with those previously published by Landolt (1992), the entire list of standard stars in this paper encompasses the magnitude range 8.90 < V < 16.30, and the color indexmore » range -0.35 < (B - V) < +2.30.« less

Determination of meteor flux distribution over the celestial sphere

NASA Technical Reports Server (NTRS)

Andreev, V. V.; Belkovich, O. I.; Filimonova, T. K.; Sidorov, V. V.

1992-01-01

A new method of determination of meteor flux density distribution over the celestial sphere is discussed. The flux density was derived from observations by radar together with measurements of angles of arrival of radio waves reflected from meteor trails. The role of small meteor showers over the sporadic background is shown.

A Study of Planetarium Effectiveness on Student Achievement, Perceptions and Retention.

ERIC Educational Resources Information Center

Ridky, Robert William

Reported is a study to determine the effect of planetarium instruction in terms of immediate attainment, attitude, and retention in the teaching of selected celestial motion and non-celestial motion concepts, when contrasted to or combined with the inquiry activities utilized by the nationally developed science curricula. Observations were made on…

The depth of the honeybee's backup sun-compass systems.

PubMed

Dovey, Katelyn M; Kemfort, Jordan R; Towne, William F

2013-06-01

Honeybees have at least three compass mechanisms: a magnetic compass; a celestial or sun compass, based on the daily rotation of the sun and sun-linked skylight patterns; and a backup celestial compass based on a memory of the sun's movements over time in relation to the landscape. The interactions of these compass systems have yet to be fully elucidated, but the celestial compass is primary in most contexts, the magnetic compass is a backup in certain contexts, and the bees' memory of the sun's course in relation to the landscape is a backup system for cloudy days. Here we ask whether bees have any further compass systems, for example a memory of the sun's movements over time in relation to the magnetic field. To test this, we challenged bees to locate the sun when their known celestial compass systems were unavailable, that is, under overcast skies in unfamiliar landscapes. We measured the bees' knowledge of the sun's location by observing their waggle dances, by which foragers indicate the directions toward food sources in relation to the sun's compass bearing. We found that bees have no celestial compass systems beyond those already known: under overcast skies in unfamiliar landscapes, bees attempt to use their landscape-based backup system to locate the sun, matching the landscapes or skylines at the test sites with those at their natal sites as best they can, even if the matches are poor and yield weak or inconsistent orientation.

On the definition and use of the ecliptic in modern astronomy

NASA Astrophysics Data System (ADS)

Capitaine, N.; Soffel, M.

2015-08-01

The ecliptic was a fundamental reference plane for astronomy from antiquity to the realization and use of the FK5 reference system. The situation has changed considerably with the adoption of the International Celestial Reference system (ICRS) by the IAU in 1998 and the IAU resolutions on reference systems that were adopted from 2000 to 2009. First, the ICRS has the property of being independent of epoch, ecliptic or equator. Second, the IAU 2000 resolutions, which specified the systems of space-time coordinates within the framework of General Relativity, for the solar system (the Barycentric Celestial Reference System, BCRS) and the Earth (the Geocentric Celestial Reference System, GCRS), did not refer to any ecliptic and did not provide a definition of a GCRS ecliptic. These resolutions also provided the definition of the pole of the nominal rotation axis (the Celestial intermediate pole, CIP) and of new origins on the equator (the Celestial and Terrestrial intermediate origins, CIO and TIO), which do not require the use of an ecliptic. Moreover, the models and standards adopted by the IAU 2006 and IAU 2009 resolutions are largely referred to the ICRS, BCRS, GCRS as well as to the new pole and origins. Therefore, the ecliptic has lost much of its importance. We review the consequences of these changes and improvements in the definition and use of the ecliptic and we discuss whether the concept of an ecliptic is still needed for some specific use in modern astronomy.

Dynamics of Natural and Artificial Celestial Bodies

NASA Astrophysics Data System (ADS)

Pretka-Ziomek, Halina; Wnuk, Edwin; Seidelmann, P. Kenneth; Richardson, David.

2002-01-01

This volume contains papers presented at the US/European Celestial Mechanics Workshop organized by the Astronomical Observatory of Adam Mickiewicz University in Poznan, Poland and held in Poznan, from 3 to 7 July 2000. The purpose of the workshop was to identify future research in celestial mechanics and astrometry and encourage collaboration among scientists from eastern and western countries. Also an emphasis was placed on attracting young members of the fields from around the world and encouraging them to undertake new research efforts needed for advancements in those fields. There was a full program of invited and contributed presentations on selected subjects and each day ended with a discussion period on a general subject in celestial mechanics. The discussion topics and the leaders were: Resonances and Chaos -- A. Morbidelli; Artificial Satellite Orbits -- K.T. Alfriend; Near Earth Objects -- K. Muinonen; Small Solar System Bodies -- I. Williams; and Summary -- P.K. Seidelmann. The goal of the discussions was to identify what we did not know and how we might further our knowledge. It was felt, in addition, that Poznan, Poland, with a core of scientists covering a range of ages, would provide an example of how a research and educational group could be developed elsewhere. Also, Poznan is a central location convenient to eastern and western countries. Thus, the gathering of people and the papers presented are to be the bases for building the future of astrometry and celestial mechanics. Link: http://www.wkap.nl/prod/b/1-4020-0115-0

Mariner 9 celestial mechanics experiment - A status report.

NASA Technical Reports Server (NTRS)

Lorell, J.; Shapiro, I. I.

1973-01-01

There are two basic efforts in the Mariner 9 celestial mechanics experiment: the determination of the gravity field of Mars and the performance of a very precise test of the theory of general relativity. In addition, there are a number of astrodynamic constants that are being determined. All the analyses are based on the Mariner 9 radio tracking data.

Relationships between log N-log S and celestial distribution of gamma-ray bursts

NASA Technical Reports Server (NTRS)

Nishimura, J.; Yamagami, T.

1985-01-01

The apparent conflict between log N-log S curve and isotropic celestial distribution of the gamma ray bursts is discussed. A possible selection effect due to the time profile of each burst is examined. It is shown that the contradiction is due to this selection effect of the gamma ray bursts.

Determination of the observation conditions of celestial bodies with the aid of the DISPO system

NASA Technical Reports Server (NTRS)

Kazakov, R. K.; Krivov, A. V.

1984-01-01

The interactive system for determining the observation conditions of celestial bodies is described. A system of programs was created containing a part of the DISPO Display Interative System of Orbit Planning. The system was used for calculating the observatiion characteristics of Halley's comet during its approach to Earth in 1985-86.

Preventing Commercial Colonialism and Retaining Sovereignty Over National Policy and Military Strategy in Space

DTIC Science & Technology

2018-04-09

29 National Interests in Space – Commercial or State-Driven Celestial Expansion? ....... 31 Celestial Market Opportunities – When Will Commercial...Space Markets Open? ...... 38 Implications of Commercial Space Operations ............................................................ 45 Chapter 5...Successful development of competitiveness involves seeking to dominate or control an existing or emergent market . The development of market domination into

Same concept…Different terms

NASA Astrophysics Data System (ADS)

Heafner, Joe

2018-03-01

Most introductory physics courses begin with the concept of an object (usually a particle) having a precise position or location in space (I will not address spacetime here) relative to something else, the origin of a three-dimensional coordinate system perhaps. My experience has been that physics students are inherently at home with this concept. In astronomy, we often begin by thinking about the sky. For the purposes of this article, I will simply define it as that which we see when we look away from Earth's surface. It appears almost as a two-dimensional plane, perhaps even a curved surface. When we look at something in the sky, we really have no sense of distance. Indeed, when astronomers need the "position" of a star or planet in the sky, the quantity is two dimensional. Because the sky appears to wrap around Earth, celestial positions can be given entirely by angular quantities. Astronomers use right ascension and declination, respectively, as analogs of terrestrial longitude and latitude. Right ascension is the angular distance eastward around the celestial equator (the projection of Earth's equator onto the celestial sphere) from the vernal equinox (where the celestial equator and the ecliptic intersect such that the Sun is moving from the Southern Hemisphere to the Northern Hemisphere) to the object and declination is the object's angular distance north or south of the celestial equator. So to an astronomer, for the purposes of aiming a telescope, position refers to a two-dimensional quantity because in the sky there is no direct sense of depth or distance.

Celestial Treasury

NASA Astrophysics Data System (ADS)

Lachièze-Rey, Marc; Luminet, Jean-Pierre

2001-07-01

Throughout history, the mysterious dark skies have inspired our imaginations in countless ways, influencing our endeavors in science and philosophy, religion, literature, and art. Filled with 380 full-color illustrations, Celestial Treasury shows the influence of astronomical theories and the richness of illustrations in Western civilization through the ages. The authors explore the evolution of our understanding of astronomy and weave together ancient and modern theories in a fascinating narrative. They incorporate a wealth of detail from Greek verse, medieval manuscripts and Victorian poetry with contemporary spacecraft photographs and computer-generated star charts. Celestial Treasury is more than a beautiful book: it answers a variety of questions that have intrigued scientists and laymen for centuries. -- How did philosophers and scientists try to explain the order that governs celestial motion? -- How did geometers and artists measure and map the skies? -- How many different answers have been proposed for the most fundamental of all questions: When and how did Earth come about? -- Who inhabits the heavens--gods, angels or extraterrestrials? No other book recounts humankind's fascination with the heavens as compellingly as Celestial Treasury. Marc Lachièze-Rey is a director of research at the Centre National pour la Récherche Scientifique and astrophysicist at the Centre d'Etudes de Saclay. He is the author of The Cosmic Background Radiation (Cambridge, 1999), and and The Quest for Unity, (Oxford, 1999 ), as well as many books in French. Jean-Pierre Luminet is a research director of the Centre National pour la Rechérche Scientifique, based at the Paris-Meudon observatory. He is the author of Black Holes, (Cambridge 1992), as well as science documentaries for television.

OPTICAL SPECTRA OF CANDIDATE INTERNATIONAL CELESTIAL REFERENCE FRAME (ICRF) FLAT-SPECTRUM RADIO SOURCES

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

Titov, O.; Stanford, Laura M.; Johnston, Helen M.

2013-07-01

Continuing our program of spectroscopic observations of International Celestial Reference Frame (ICRF) sources, we present redshifts for 120 quasars and radio galaxies. Data were obtained with five telescopes: the 3.58 m European Southern Observatory New Technology Telescope, the two 8.2 m Gemini telescopes, the 2.5 m Nordic Optical Telescope (NOT), and the 6.0 m Big Azimuthal Telescope of the Special Astrophysical Observatory in Russia. The targets were selected from the International VLBI Service for Geodesy and Astrometry candidate International Celestial Reference Catalog which forms part of an observational very long baseline interferometry (VLBI) program to strengthen the celestial reference frame.more » We obtained spectra of the potential optical counterparts of more than 150 compact flat-spectrum radio sources, and measured redshifts of 120 emission-line objects, together with 19 BL Lac objects. These identifications add significantly to the precise radio-optical frame tie to be undertaken by Gaia, due to be launched in 2013, and to the existing data available for analyzing source proper motions over the celestial sphere. We show that the distribution of redshifts for ICRF sources is consistent with the much larger sample drawn from Faint Images of the Radio Sky at Twenty cm (FIRST) and Sloan Digital Sky Survey, implying that the ultra-compact VLBI sources are not distinguished from the overall radio-loud quasar population. In addition, we obtained NOT spectra for five radio sources from the FIRST and NRAO VLA Sky Survey catalogs, selected on the basis of their red colors, which yielded three quasars with z > 4.« less

Sensitivity Analysis and Mitigation with Applications to Ballistic and Low-thrust Trajectory Design

NASA Astrophysics Data System (ADS)

Alizadeh, Iman

The ever increasing desire to expand space mission capabilities within the limited budgets of space industries requires new approaches to the old problem of spacecraft trajectory design. For example, recent initiatives for space exploration involve developing new tools to design low-cost, fail-safe trajectories to visit several potential destinations beyond our celestial neighborhood such as Jupiter's moons, asteroids, etc. Designing and navigating spacecraft trajectories to reach these destinations safely are complex and challenging. In particular, fundamental questions of orbital stability imposed by planetary protection requirements are not easily taken into account by standard optimal control schemes. The event of temporary engine loss or an unexpected missed thrust can indeed quickly lead to impact with planetary bodies or other unrecoverable trajectories. While electric propulsion technology provides superior efficiency compared to chemical engines, the very low-control authority and engine performance degradation can impose higher risk to the mission in strongly perturbed orbital environments. The risk is due to the complex gravitational field and its associated chaotic dynamics which causes large navigation dispersions in a short time if left un-controlled. Moreover, in these situations it can be outside the low-thrust propulsion system capability to correct the spacecraft trajectory in a reasonable time frame. These concerns can lead to complete or partial mission failure or even an infeasible mission concept at the early design stage. The goal of this research is to assess and increase orbital stability of ballistic and low-thrust transfer trajectories in multi-body systems. In particular, novel techniques are presented to characterize sensitivity and improve recovery characteristics of ballistic and low-thrust trajectories in unstable orbital environments. The techniques developed are based on perturbation analysis around ballistic trajectories to determine analytically the maximum divergence directions and also optimal control theory with nonstandard cost functions along with inverse dynamics applied to low-thrust trajectories. Several mission scenarios are shown to demonstrate the applicability of the techniques in the Earth-Moon and the Jupiter-Europa system. In addition, the results provide fundamental insight into design, stability analysis and guidance, navigation and control of low-thrust trajectories to meet challenging mission requirements in support of NASA's vision for space exploration.

Dark Energy Survey finds more celestial neighbors | News

Science.gov Websites

Energy Survey finds more celestial neighbors August 17, 2015 icon icon icon New dwarf galaxy candidates could mean our sky is more crowded than we thought The Dark Energy Survey has now mapped one-eighth of Survey Collaboration The Dark Energy Survey has now mapped one-eighth of the full sky (red shaded region

Children Learning to Explain Daily Celestial Motion: Understanding Astronomy across Moving Frames of Reference

ERIC Educational Resources Information Center

Plummer, Julia D.; Wasko, Kyle D.; Slagle, Cynthia

2011-01-01

This study investigated elementary students' explanations for the daily patterns of apparent motion of the Sun, Moon, and stars. Third-grade students were chosen for this study because this age level is at the lower end of when many US standards documents suggest students should learn to use the Earth's rotation to explain daily celestial motion.…

The dynamical behaviour of our planetary system. Proceedings. 4th Alexander von Humboldt Colloquium on Celestial Mechanics, Ramsau (Austria), 17 - 23 Mar 1996.

NASA Astrophysics Data System (ADS)

Dvorak, R.; Henrard, J.

1996-03-01

The following topics were dealt with: celestial mechanics, dynamical astronomy, planetary systems, resonance scattering, Hamiltonian mechanics non-integrability, irregular periodic orbits, escape, dynamical system mapping, fast Fourier method, precession-nutation, Nekhoroshev theorem, asteroid dynamics, the Trojan problem, planet-crossing orbits, Kirkwood gaps, future research, human comprehension limitations.

Celestial mechanics during the last two decades

NASA Technical Reports Server (NTRS)

Szebehely, V.

1978-01-01

The unprecedented progress in celestial mechanics (orbital mechanics, astrodynamics, space dynamics) is reviewed from 1957 to date. The engineering, astronomical and mathematical aspects are synthesized. The measuring and computational techniques developed parallel with the theoretical advances are outlined. Major unsolved problem areas are listed with proposed approaches for their solutions. Extrapolations and predictions of the progress for the future conclude the paper.

Johannes Kepler and the Supernova of 1604

NASA Astrophysics Data System (ADS)

Boner, P. J.

2006-08-01

The brilliant luminary that first appeared in October 1604 was considered by many contemporaries to be a new star of unrivalled magnitude. Shining forth near the historic conjunction of Mars, Jupiter and Saturn, the new star held important implications for several areas of interest, notably astrology, astronomy, chronology and theology. Addressing all of these areas in his comprehensive book, De stella nova (1606), Johannes Kepler (1571-1630) studied the new star extensively under the aegis of Holy Roman Emperor Rudolf II (1552-1612) in Prague. The focus of the following presentation is Kepler's theory of the new star's origins in the celestial ether. Describing the heavens poetically as a fertile expanse of "liquid fields", Kepler suggested that the new star sprung from the celestial ether much like the numerous living beings in the sublunary realm which were spontaneously generated from the Earth. As evidence for his claim, Kepler pointed to the conspicuous mathematical patterns similarly observed in earthly and celestial entities. Kepler's efficient cause for this explanation, known as the animate faculty, accounted for both the generation and form of new phenomena in the celestial and terrestrial realms. The new star of 1604 proved to be no exception.

The role of the sun in the celestial compass of dung beetles

PubMed Central

Dacke, M.; el Jundi, Basil; Smolka, Jochen; Byrne, Marcus; Baird, Emily

2014-01-01

Recent research has focused on the different types of compass cues available to ball-rolling beetles for orientation, but little is known about the relative precision of each of these cues and how they interact. In this study, we find that the absolute orientation error of the celestial compass of the day-active dung beetle Scarabaeus lamarcki doubles from 16° at solar elevations below 60° to an error of 29° at solar elevations above 75°. As ball-rolling dung beetles rely solely on celestial compass cues for their orientation, these insects experience a large decrease in orientation precision towards the middle of the day. We also find that in the compass system of dung beetles, the solar cues and the skylight cues are used together and share the control of orientation behaviour. Finally, we demonstrate that the relative influence of the azimuthal position of the sun for straight-line orientation decreases as the sun draws closer to the horizon. In conclusion, ball-rolling dung beetles possess a dynamic celestial compass system in which the orientation precision and the relative influence of the solar compass cues change over the course of the day. PMID:24395963

The role of the sun in the celestial compass of dung beetles.

PubMed

Dacke, M; el Jundi, Basil; Smolka, Jochen; Byrne, Marcus; Baird, Emily

2014-01-01

Recent research has focused on the different types of compass cues available to ball-rolling beetles for orientation, but little is known about the relative precision of each of these cues and how they interact. In this study, we find that the absolute orientation error of the celestial compass of the day-active dung beetle Scarabaeus lamarcki doubles from 16° at solar elevations below 60° to an error of 29° at solar elevations above 75°. As ball-rolling dung beetles rely solely on celestial compass cues for their orientation, these insects experience a large decrease in orientation precision towards the middle of the day. We also find that in the compass system of dung beetles, the solar cues and the skylight cues are used together and share the control of orientation behaviour. Finally, we demonstrate that the relative influence of the azimuthal position of the sun for straight-line orientation decreases as the sun draws closer to the horizon. In conclusion, ball-rolling dung beetles possess a dynamic celestial compass system in which the orientation precision and the relative influence of the solar compass cues change over the course of the day.

Mariner Mars 1971 attitude control subsystem

NASA Technical Reports Server (NTRS)

Edmunds, R. S.

1974-01-01

The Mariner Mars 1971 attitude control subsystem (ACS) is discussed. It is comprised of a sun sensor set, a Canopus tracker, an inertial reference unit, two cold gas reaction control assemblies, two rocket engine gimbal actuators, and an attitude control electronics unit. The subsystem has the following eight operating modes: (1) launch, (2) sun acquisition, (3) roll search, (4) celestial cruise, (5) all-axes inertial, (6) roll inertial, (7) commanded turn, and (8) thrust vector control. In the celestial cruise mode, the position control is held to plus or minus 0.25 deg. Commanded turn rates are plus or minus 0.18 deg/s. The attitude control logic in conjunction with command inputs from other spacecraft subsystems establishes the ACS operating mode. The logic utilizes Sun and Canopus acquisition signals generated within the ACS to perform automatic mode switching so that dependence of ground control is minimized when operating in the sun acquisition, roll search, and celestial cruise modes. The total ACS weight is 65.7 lb, and includes 5.4 lb of nitrogen gas. Total power requirements vary from 9 W for the celestial cruise mode to 54 W for the commanded turn mode.

[The celestial phenomena in A. Dürer's engraving Melancholia I].

PubMed

Weitzel, Hans

2009-01-01

The celestial body of Dürer's engraving Melencolia I is connected with his painting of a meteor, the Raveningham-painting; it is shown that the origin of this painting owns to the impact of the meteor of Ensisheim in 1492. Until now the celestial body, the balance, and the magic square are nearly consistently interpreted as the planet Saturn, the zodiac sign Libra, and the planet Jupiter, and the melancholy woman is subject to these heavenly bodies. Consequently, neoplatonic astrology has been the main focus of the engraving; including the rainbow, the engraving has also been interpreted biblically. The present paper, however, places emphasis on problems of the geometry as the reason of melancholy. Any astronomical meaning of the configuration of the numbers of the magic square is discarded.

Heavenly Networks. Celestial Maps and Globes in Circulation between Artisans, Mathematicians, and Noblemen in Renaissance Europe.

PubMed

Gessner, Samuel

2015-01-01

The aim of this paper is to examine the iconography on a set of star charts by Albrecht Dürer (1515), and celestial globes by Caspar Vopel (1536) and Christoph Schissler (1575). The iconography on these instruments is conditioned by strong traditions which include not only the imagery on globes and planispheres (star charts), but also ancient literature about the constellations. Where this iconography departs from those traditions, the change had to do with humanism in the sixteenth century. This "humanistic" dimension is interwoven with other concerns that involve both "social" and "technical" motivations. The interplay of these three dimensions illustrates how the iconography on celestial charts and globes expresses some features of the shared knowledge and shared culture between artisans, mathematicians, and nobles in Renaissance Europe.

Calibration of magnetic and celestial compass cues in migratory birds--a review of cue-conflict experiments.

PubMed

Muheim, Rachel; Moore, Frank R; Phillips, John B

2006-01-01

Migratory birds use multiple sources of compass information for orientation, including the geomagnetic field, the sun, skylight polarization patterns and star patterns. In this paper we review the results of cue-conflict experiments designed to determine the relative importance of the different compass mechanisms, and how directional information from these compass mechanisms is integrated. We focus on cue-conflict experiments in which the magnetic field was shifted in alignment relative to natural celestial cues. Consistent with the conclusions of earlier authors, our analyses suggest that during the premigratory season, celestial information is given the greatest salience and used to recalibrate the magnetic compass by both juvenile and adult birds. Sunset polarized light patterns from the region of the sky near the horizon appear to provide the calibration reference for the magnetic compass. In contrast, during migration, a majority of experiments suggest that birds rely on the magnetic field as the primary source of compass information and use it to calibrate celestial compass cues, i.e. the relative saliency of magnetic and celestial cues is reversed. An alternative possibility, however, is suggested by several experiments in which birds exposed to a cue conflict during migration appear to have recalibrated the magnetic compass, i.e. their response is similar to that of birds exposed to cue conflicts during the premigratory season. The general pattern to emerge from these analyses is that birds exposed to the cue conflict with a view of the entire sunset sky tended to recalibrate the magnetic compass, regardless of whether the cue conflict occurred during the premigratory or migratory period. In contrast, birds exposed to the cue conflict in orientation funnels and registration cages that restricted their view of the region of sky near the horizon (as was generally the case in experiments carried out during the migratory season) did not recalibrate the magnetic compass but, instead, used the magnetic compass to calibrate the other celestial compass systems. If access to critical celestial cues, rather than the timing of exposure to the cue conflict (i.e. premigratory vs migratory), determines whether recalibration of the magnetic compass occurs, this suggests that under natural conditions there may be a single calibration reference for all of the compass systems of migratory birds that is derived from sunset (and possibly also sunrise) polarized light cues from the region of sky near the horizon. In cue-conflict experiments carried out during the migratory season, there was also an interesting asymmetry in the birds' response to magnetic fields shifted clockwise and counterclockwise relative to celestial cues. We discuss two possible explanations for these differences: (1) lateral asymmetry in the role of the right and left eye in mediating light-dependent magnetic compass orientation and (2) interference from the spectral and intensity distribution of skylight at sunset with the response of the light-dependent magnetic compass.

Building a Learning Progression for Celestial Motion: An Exploration of Students' Reasoning about the Seasons

ERIC Educational Resources Information Center

Plummer, Julia D.; Maynard, L.

2014-01-01

We present the development of a construct map addressing the reason for the seasons, as a subset of a larger learning progression on celestial motion. Five classes of 8th grade students (N?=?38) participated in a 10-day curriculum on the seasons. We revised a hypothetical seasons construct map using a Rasch model analysis of students'…

High-Resolution Structural Monitoring of Ionospheric Absorption Events

DTIC Science & Technology

2013-07-01

ionospheric plasma conductivity 5 . This results in enhanced absorption of the cosmic high frequency (HF; typically 10 – 60 MHz) radio background ...7 riometry. Incorporation of an outrigger site, to enable treatment of the unknown structure of the celestial background and the effects of...riometry. Incorporation of an outrigger site, to enable treatment of the unknown structure of the celestial background and the effects of confusion

The General History of Astronomy

NASA Astrophysics Data System (ADS)

Taton, René; Wilson, Curtis; Hoskin, editor Michael, , General

2009-09-01

Part V. Early Phases in the Reception of Newton's Theory: 14. The vortex theory in competition with Newtonian celestial dynamics Eric J. Aiton; 15. The shape of the Earth Seymour L. Chapin; 16. Clairaut and the motion of the lunar apse: The inverse-square law undergoes a test Craig B. Waff; 17. The precession of the equinoxes from Newton to d'Alembert and Euler Curtis Wilson; 18. The solar tables of Lacaille and the lunar tables of Mayer Eric G. Forbes and Curtis Wilson; 19. Predicting the mid-eighteenth-century return of Halley's Comet Craig B. Waff; Part VI. Celestial Mechanics During the Eighteenth Century: 20. The problem of perturbation analytically treated: Euler, Clairaut, d'Alembert Curtis Wilson; 21. The work of Lagrange in celestial mechanics Curtis Wilson; 22. Laplace Bruno Morando; Part VII. Observational Astronomy and the Application of Theory in the Late Eighteenth and Early Nineteenth Century: 23. Measuring solar parallax: The Venus transits of 1761 and 1769 and their nineteenth-century sequels Albert Van Helden; 24. The discovery of Uranus, the Titius-Bode and the asteroids Michael Hoskin; 25. Eighteenth-and nineteenth century developments in the theory and practice of orbit determination Brian G. Marsden; 26. The introduction of statistical reasoning into astronomy: from Newton to Poincaré Oscar Sheynin; 27. Astronomy and the theory of errors: from the method of averages to the method of least squares F. Schmeidler; Part VIII. The Development of Theory During the Nineteenth Century: 28. The golden age of celestial mechanics Bruno Morando; Part IX. The Application of Celestial Mechanics to the Solar System to the End of the Nineteenth Century: 29. Three centuries of lunar and planetary ephemerides and tables Bruno Morando; 30. Satellite ephemerides to 1900 Yoshihide Kozai; Illustrations; Combined index for Parts 2A and 2B.

Concise CIO based precession-nutation formulations

NASA Astrophysics Data System (ADS)

Capitaine, N.; Wallace, P. T.

2008-01-01

Context: The IAU 2000/2006 precession-nutation models have precision goals measured in microarcseconds. To reach this level of performance has required series containing terms at over 1300 frequencies and involving several thousand amplitude coefficients. There are many astronomical applications for which such precision is not required and the associated heavy computations are wasteful. This justifies developing smaller models that achieve adequate precision with greatly reduced computing costs. Aims: We discuss strategies for developing simplified IAU 2000/2006 precession-nutation procedures that offer a range of compromises between accuracy and computing costs. Methods: The chain of transformations linking celestial and terrestrial coordinates comprises frame bias, precession-nutation, Earth rotation and polar motion. We address the bias and precession-nutation (NPB) portion of the chain, linking the Geocentric Celestial Reference System (GCRS) with the Celestial Intermediate Reference System (CIRS), the latter based on the Celestial Intermediate Pole (CIP) and Celestial Intermediate Origin (CIO). Starting from direct series that deliver the CIP coordinates X,Y and (via the quantity s + XY/2) the CIO locator s, we look at the opportunities for simplification. Results: The biggest reductions come from truncating the series, but some additional gains can be made in the areas of the matrix formulation, the expressions for the nutation arguments and by subsuming long period effects into the bias quantities. Three example models are demonstrated that approximate the IAU 2000/2006 CIP to accuracies of 1 mas, 16 mas and 0.4 arcsec throughout 1995-2050 but with computation costs reduced by 1, 2 and 3 orders of magnitude compared with the full model. Appendices A to G are only available in electronic form at http://www.aanda.org

Celestial polarization patterns during twilight.

PubMed

Cronin, Thomas W; Warrant, Eric J; Greiner, Birgit

2006-08-01

Scattering of sunlight produces patterns of partially linearly polarized light in the sky throughout the day, and similar patterns appear at night when the Moon is bright. We studied celestial polarization patterns during the period of twilight, when the Sun is below the horizon, determining the degree and orientation of the polarized-light field and its changes before sunrise and after sunset. During twilight, celestial polarized light occurs in a wide band stretching perpendicular to the location of the hidden Sun and reaching typical degrees of polarization near 80% at wavelengths >600 nm. In the tropics, this pattern appears approximately 1 h before local sunrise or disappears approximately 1 h after local sunset (within 10 min. after the onset of astronomical twilight at dawn, or before its end at dusk) and extends with little change through the entire twilight period.

The Importance of Primary Martian Surface and Airfall Dust Sample Return for Toxicological Hazard Evaluations for Human Exploration

NASA Technical Reports Server (NTRS)

Harrington, A. D.; McCubbin, F. M.

2018-01-01

Manned missions to the Moon highlight a major hazard for future human exploration of the Moon and beyond: surface dust. Not only did the dust cause mechanical and structural integrity issues with the suits, the dust 'storm' generated upon reentrance into the crew cabin caused "lunar hay fever" and "almost blindness" . It was further reported that the allergic response to the dust worsened with each exposure. Due to the prevalence of these high exposures, the Human Research Roadmap developed by NASA identifies the Risk of Adverse Health and Performance Effects of Celestial Dust Exposure as an area of concern. Extended human exploration will further increase the probability of inadvertent and repeated exposures to celestial dusts. Going forward, hazard assessments of celestial dusts will be determined through sample return efforts prior to astronaut deployment.

KSC-07pd2423

NASA Image and Video Library

2007-09-11

KENNEDY SPACE CENTER, FLA. -- The Dawn spacecraft is moved out of the Astrotech Space Operations facility, on its way to Launch Pad 17-B at Cape Canaveral Air Force Station. At the pad, Dawn will be lifted into the mobile service tower and prepared for mating with the awaiting Delta II rocket. Dawn is scheduled for launch in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Photo credit: NASA/Jack Pfaller

KSC-07pd2405

NASA Image and Video Library

2007-09-10

KENNEDY SPACE CENTER, FLA. -- At Astrotech Space Operations in Titusville, Fla., workers guide the upper transportation canister toward the Dawn spacecraft in the background. The canister will be lowered onto the lower segments and attached. The canister will protect the spacecraft and booster during transfer to Launch Pad 17-B at Cape Canaveral Air Force Station (CCAFS). During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch via a Delta II rocket is scheduled in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. Photo credit: NASA/Jim Grossmann

Optical technologies for space sensor

NASA Astrophysics Data System (ADS)

Wang, Hu; Liu, Jie; Xue, Yaoke; Liu, Yang; Liu, Meiying; Wang, Lingguang; Yang, Shaodong; Lin, Shangmin; Chen, Su; Luo, Jianjun

2015-10-01

Space sensors are used in navigation sensor fields. The sun, the earth, the moon and other planets are used as frame of reference to obtain stellar position coordinates, and then to control the attitude of an aircraft. Being the "eyes" of the space sensors, Optical sensor system makes images of the infinite far stars and other celestial bodies. It directly affects measurement accuracy of the space sensor, indirectly affecting the data updating rate. Star sensor technology is the pilot for Space sensors. At present more and more attention is paid on all-day star sensor technology. By day and night measurements of the stars, the aircraft's attitude in the inertial coordinate system can be provided. Facing the requirements of ultra-high-precision, large field of view, wide spectral range, long life and high reliability, multi-functional optical system, we integration, integration optical sensors will be future space technology trends. In the meantime, optical technologies for space-sensitive research leads to the development of ultra-precision optical processing, optical and precision test machine alignment technology. It also promotes the development of long-life optical materials and applications. We have achieved such absolute distortion better than ±1um, Space life of at least 15years of space-sensitive optical system.

KSC-07pd2407

NASA Image and Video Library

2007-09-10

KENNEDY SPACE CENTER, FLA. -- At Astrotech Space Operations in Titusville, Fla., workers watch as the upper transportation canister is lowered over the Dawn spacecraft. The canister will be attached to the bottom segments already in place. The canister will protect the spacecraft and booster during transfer to Launch Pad 17-B at Cape Canaveral Air Force Station (CCAFS). During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch via a Delta II rocket is scheduled in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. Photo credit: NASA/Jim Grossmann

KSC-07pd2444

NASA Image and Video Library

2007-09-11

KENNEDY SPACE CENTER, FLA. -- In the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station, workers remove the lower segments of the transportation canister away from the Dawn spacecraft. After removal of the canister, Dawn will be mated with the waiting Delta II rocket. Dawn is scheduled for launch in a window from 7:25 to 7:54 a.m. EDT Sept. 26 from CCAFS. During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Photo credit: NASA/Jim Grossmann

KSC-07pd2403

NASA Image and Video Library

2007-09-10

KENNEDY SPACE CENTER, FLA. -- At Astrotech Space Operations in Titusville, Fla., workers place another segment of the transportation canister around the upper stage booster beneath the Dawn spacecraft. The canister will protect the spacecraft and booster during transfer to Launch Pad 17-B at Cape Canaveral Air Force Station (CCAFS). During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch via a Delta II rocket is scheduled in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. Photo credit: NASA/Jim Grossmann

KSC-07pd2409

NASA Image and Video Library

2007-09-10

KENNEDY SPACE CENTER, FLA. -- At Astrotech Space Operations in Titusville, Fla., workers ensure the upper transportation canister is securely attached to the lower segments. The transportation canister will protect the spacecraft and booster during transfer to Launch Pad 17-B at Cape Canaveral Air Force Station (CCAFS). During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch via a Delta II rocket is scheduled in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. Photo credit: NASA/Jim Grossmann

KSC-07pd2404

NASA Image and Video Library

2007-09-10

KENNEDY SPACE CENTER, FLA. -- At Astrotech Space Operations in Titusville, Fla., workers check the fitting on the lower transportation canister segments in place around the upper stage booster beneath the Dawn spacecraft. The canister will protect the spacecraft and booster during transfer to Launch Pad 17-B at Cape Canaveral Air Force Station (CCAFS). During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch via a Delta II rocket is scheduled in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. Photo credit: NASA/Jim Grossmann

KSC-07pd2402

NASA Image and Video Library

2007-09-10

KENNEDY SPACE CENTER, FLA. -- At Astrotech Space Operations in Titusville, Fla., workers place the lower segments of the transportation canister around the upper stage booster beneath the Dawn spacecraft. The canister will protect the spacecraft and booster during transfer to Launch Pad 17-B at Cape Canaveral Air Force Station (CCAFS). During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch via a Delta II rocket is scheduled in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. Photo credit: NASA/Jim Grossmann

KSC-07pd2406

NASA Image and Video Library

2007-09-10

KENNEDY SPACE CENTER, FLA. -- At Astrotech Space Operations in Titusville, Fla., workers guide the upper transportation canister as it is lowered onto the Dawn spacecraft. The canister will be attached to the bottom segments already in place. The canister will protect the spacecraft and booster during transfer to Launch Pad 17-B at Cape Canaveral Air Force Station (CCAFS). During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch via a Delta II rocket is scheduled in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. Photo credit: NASA/Jim Grossmann

KSC-98pc1208

NASA Image and Video Library

1998-10-02

KENNEDY SPACE CENTER, FLA. -- KSC workers prepare Deep Space 1 for a spin test on the E6R Spin Balance Machine at the Defense Satellite Communications System Processing Facility (DPF), Cape Canaveral Air Station. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include a solar-powered ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. The ion propulsion engine is the first non-chemical propulsion to be used as the primary means of propelling a spacecraft. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. The spacecraft will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, Cape Canaveral Air Station, in October. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches

KSC-98pc1195

NASA Image and Video Library

1998-10-01

Workers at this clean room facility, Cape Canaveral Air Station, maneuver the protective can that covered Deep Space 1 during transportation from KSC away from the spacecraft. Deep Space 1 will undergo spin testing at the site. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include a solar-powered ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. The ion propulsion engine is the first non-chemical propulsion to be used as the primary means of propelling a spacecraft. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. The spacecraft will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, Cape Canaveral Air Station, in October. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches

KSC-98pc1209

NASA Image and Video Library

1998-10-02

KENNEDY SPACE CENTER, FLA. -- KSC workers give a final check to Deep Space 1 before starting a spin test on the spacecraft at the Defense Satellite Communications System Processing Facility (DPF), Cape Canaveral Air Station. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include a solar-powered ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. The ion propulsion engine is the first non-chemical propulsion to be used as the primary means of propelling a spacecraft. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. The spacecraft will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, Cape Canaveral Air Station, in October. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches

KSC-98pc1193

NASA Image and Video Library

1998-09-30

KENNEDY SPACE CENTER, FLA. -- KSC workers lower the "can" over Deep Space 1. The can will protect the spacecraft during transport to the Defense Satellite Communications System Processing Facility (DPF), Cape Canaveral Air Station, for testing. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include a solar-powered ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. The ion propulsion engine is the first non-chemical propulsion to be used as the primary means of propelling a spacecraft. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. The spacecraft will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, Cape Canaveral Air Station, in October. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches

Walking Drosophila align with the e-vector of linearly polarized light through directed modulation of angular acceleration

PubMed Central

Velez, Mariel M.; Wernet, Mathias F.; Clark, Damon A.

2014-01-01

Understanding the mechanisms that link sensory stimuli to animal behavior is a central challenge in neuroscience. The quantitative description of behavioral responses to defined stimuli has led to a rich understanding of different behavioral strategies in many species. One important navigational cue perceived by many vertebrates and insects is the e-vector orientation of linearly polarized light. Drosophila manifests an innate orientation response to this cue (‘polarotaxis’), aligning its body axis with the e-vector field. We have established a population-based behavioral paradigm for the genetic dissection of neural circuits guiding polarotaxis to both celestial as well as reflected polarized stimuli. However, the behavioral mechanisms by which flies align with a linearly polarized stimulus remain unknown. Here, we present a detailed quantitative description of Drosophila polarotaxis, systematically measuring behavioral parameters that are modulated by the stimulus. We show that angular acceleration is modulated during alignment, and this single parameter may be sufficient for alignment. Furthermore, using monocular deprivation, we show that each eye is necessary for modulating turns in the ipsilateral direction. This analysis lays the foundation for understanding how neural circuits guide these important visual behaviors. PMID:24810784

Deep Space 1 moves to CCAS for testing

NASA Technical Reports Server (NTRS)

1998-01-01

KSC workers lower the 'can' over Deep Space 1. The can will protect the spacecraft during transport to the Defense Satellite Communications System Processing Facility (DPF), Cape Canaveral Air Station, for testing. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include a solar-powered ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. The ion propulsion engine is the first non- chemical propulsion to be used as the primary means of propelling a spacecraft. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. The spacecraft will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, Cape Canaveral Air Station, in October. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches.

Deep Space 1 is prepared for spin test at CCAS

NASA Technical Reports Server (NTRS)

1998-01-01

KSC workers give a final check to Deep Space 1 before starting a spin test on the spacecraft at the Defense Satellite Communications System Processing Facility (DPF), Cape Canaveral Air Station. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include a solar-powered ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. The ion propulsion engine is the first non-chemical propulsion to be used as the primary means of propelling a spacecraft. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. The spacecraft will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, Cape Canaveral Air Station, in October. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches.

Deep Space 1 is prepared for spin test at CCAS

NASA Technical Reports Server (NTRS)

1998-01-01

KSC workers prepare Deep Space 1 for a spin test on the E6R Spin Balance Machine at the Defense Satellite Communications System Processing Facility (DPF), Cape Canaveral Air Station. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include a solar-powered ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. The ion propulsion engine is the first non-chemical propulsion to be used as the primary means of propelling a spacecraft. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. The spacecraft will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, Cape Canaveral Air Station, in October. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches.

Ion propulsion engine installed on Deep Space 1 at CCAS

NASA Technical Reports Server (NTRS)

1998-01-01

Workers at the Defense Satellite Communications System Processing Facility (DPF), Cape Canaveral Air Station (CCAS), attach a strap during installation of the ion propulsion engine on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS, in October.

Ion propulsion engine installed on Deep Space 1 at CCAS

NASA Technical Reports Server (NTRS)

1998-01-01

Workers in the Defense Satellite Communications Systems Processing Facility (DPF) at Cape Canaveral Air Station (CCAS) finish installing the ion propulsion engine on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched Oct. 25 aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS.

Ion propulsion engine installed on Deep Space 1 at CCAS

NASA Technical Reports Server (NTRS)

1998-01-01

Workers at the Defense Satellite Communications System Processing Facility (DPF), Cape Canaveral Air Station (CCAS), maneuver the ion propulsion engine into place before installation on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight- tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS, in October.

Ion propulsion engine installed on Deep Space 1 at CCAS

NASA Technical Reports Server (NTRS)

1998-01-01

Workers at the Defense Satellite Communications System Processing Facility (DPF), Cape Canaveral Air Station (CCAS), install an ion propulsion engine on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS, in October.

Ion propulsion engine installed on Deep Space 1 at CCAS

NASA Technical Reports Server (NTRS)

1998-01-01

Workers in the Defense Satellite Communications Systems Processing Facility (DPF) at Cape Canaveral Air Station (CCAS) make adjustments while installing the ion propulsion engine on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight- tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched Oct. 25 aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS.

Ion propulsion engine installed on Deep Space 1 at CCAS

NASA Technical Reports Server (NTRS)

1998-01-01

Workers at the Defense Satellite Communications System Processing Facility (DPF), Cape Canaveral Air Station (CCAS), make adjustments while installing the ion propulsion engine on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight- tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS, in October.

Deep Space 1 is encapsulated on launch pad

NASA Technical Reports Server (NTRS)

1998-01-01

On Launch Pad 17A at Cape Canaveral Air Station, released from its protective payload transportation container, Deep Space 1 waits to have the fairing attached before launch. Targeted for launch aboard a Boeing Delta 7326 rocket on Oct. 25, Deep Space 1 is the first flight in NASA's New Millennium Program, and is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

Deep Space 1 is prepared for transport to launch pad

NASA Technical Reports Server (NTRS)

1998-01-01

Workers in the Defense Satellite Communication Systems Processing Facility (DPF), Cape Canaveral Air Station (CCAS), move to the workstand the second conical section leaf of the payload transportation container for Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS.

Deep Space 1 is prepared for transport to launch pad

NASA Technical Reports Server (NTRS)

1998-01-01

Workers in the Defense Satellite Communication Systems Processing Facility (DPF), Cape Canaveral Air Station (CCAS), begin attaching the conical section leaves of the payload transportation container on Deep Space 1 before launch, targeted for Oct. 25 aboard a Boeing Delta 7326 rocket from Launch Pad 17A. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight- tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

KSC-98pc1328

NASA Image and Video Library

1998-10-12

KENNEDY SPACE CENTER, FLA. -- Wrapped in an anti-static blanket for protection, Deep Space 1 is moved out of the Defense Satellite Communications Systems Processing Facility (DPF) at Cape Canaveral Air Station (CCAS) for its trip to Launch Pad 17A. The spacecraft will be launched aboard a Boeing Delta 7326 rocket on Oct. 25. Deep Space 1 is the first flight in NASA's New Millennium Program, and is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1345

NASA Image and Video Library

1998-10-16

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17A at Cape Canaveral Air Station, released from its protective payload transportation container, Deep Space 1 waits to have the fairing attached before launch. Targeted for launch aboard a Boeing Delta 7326 rocket on Oct. 25, Deep Space 1 is the first flight in NASA's New Millennium Program, and is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1329

NASA Image and Video Library

1998-10-12

KENNEDY SPACE CENTER, FLA. -- Wrapped in an anti-static blanket for protection, Deep Space 1 is lifted out of the transporter that carried it to Launch Pad 17A at Cape Canaveral Air Station. The spacecraft will be launched aboard a Boeing Delta 7326 rocket on Oct. 25. Deep Space 1 is the first flight in NASA's New Millennium Program, and is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1261

NASA Image and Video Library

1998-10-07

KENNEDY SPACE CENTER, FLA. -- Workers at the Defense Satellite Communications System Processing Facility (DPF), Cape Canaveral Air Station (CCAS), attach a strap during installation of the ion propulsion engine on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS, in October

KSC-98pc1318

NASA Image and Video Library

1998-10-10

KENNEDY SPACE CENTER, FLA. - Wrapped in an antistatic blanket for protection, Deep Space 1 is moved out of the Defense Satellite Communications System Processing Facility (DPF) at Cape Canaveral Air Station (CCAS) for its trip to Launch Pad 17A. The spacecraft will be launched aboard Boeing's Delta 7326 rocket in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including an ion propulsion engine. Propelled by the gas xenon, the engine is being flight tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include softwre that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the firs two months, but will also make a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

KSC-98pc1262

NASA Image and Video Library

1998-10-07

KENNEDY SPACE CENTER, FLA. -- Workers at the Defense Satellite Communications System Processing Facility (DPF), Cape Canaveral Air Station (CCAS), make adjustments while installing the ion propulsion engine on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS, in October

KSC-98pc1264

NASA Image and Video Library

1998-10-07

KENNEDY SPACE CENTER, FLA. -- Workers in the Defense Satellite Communications Systems Processing Facility (DPF) at Cape Canaveral Air Station (CCAS) make adjustments while installing the ion propulsion engine on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched Oct. 25 aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS

KSC-98pc1313

NASA Image and Video Library

1998-10-10

KENNEDY SPACE CENTER, FLA. -- Workers in the Defense Satellite Communication Systems Processing Facility (DPF), Cape Canaveral Air Station (CCAS), begin attaching the conical section leaves of the payload transportation container on Deep Space 1 before launch, targeted for Oct. 25 aboard a Boeing Delta 7326 rocket from Launch Pad 17A. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1260

NASA Image and Video Library

1998-10-07

KENNEDY SPACE CENTER, FLA. -- Workers at the Defense Satellite Communications System Processing Facility (DPF), Cape Canaveral Air Station (CCAS), install an ion propulsion engine on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS, in October

KSC-98pc1332

NASA Image and Video Library

1998-10-12

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17A at Cape Canaveral Air Station, Deep Space 1 is lowered toward the second stage of a Boeing Delta 7326 rocket. The adapter on the spacecraft can be seen surrounding the booster motor. Targeted for launch on Oct. 25, Deep Space 1 is the first flight in NASA's New Millennium Program, and is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1347

NASA Image and Video Library

1998-10-16

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17A at Cape Canaveral Air Station, workers maneuver part of the fairing (viewed from the inside) to encapsulate Deep Space 1. Targeted for launch aboard a Boeing Delta 7326 rocket on Oct. 25, Deep Space 1 is the first flight in NASA's New Millennium Program, and is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1265

NASA Image and Video Library

1998-10-07

KENNEDY SPACE CENTER, FLA. -- Workers in the Defense Satellite Communications Systems Processing Facility (DPF) at Cape Canaveral Air Station (CCAS) finish installing the ion propulsion engine on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched Oct. 25 aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS

KSC-98pc1263

NASA Image and Video Library

1998-10-07

KENNEDY SPACE CENTER, FLA. -- Workers at the Defense Satellite Communications System Processing Facility (DPF), Cape Canaveral Air Station (CCAS), maneuver the ion propulsion engine into place before installation on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS, in October

KSC-98pc1330

NASA Image and Video Library

1998-10-12

KENNEDY SPACE CENTER, FLA. -- Just before sunrise, on Launch Pad 17A at Cape Canaveral Air Station, Deep Space 1 is hoisted up the mobile service tower for installation on a Boeing Delta 7326 rocket . The spacecraft is targeted for launch on Oct. 25. Deep Space 1 is the first flight in NASA's New Millennium Program, and is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1314

NASA Image and Video Library

1998-10-10

KENNEDY SPACE CENTER, FLA. -- Workers in the Defense Satellite Communication Systems Processing Facility (DPF), Cape Canaveral Air Station (CCAS), move to the workstand the second conical section leaf of the payload transportation container for Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS

Tree-level gluon amplitudes on the celestial sphere

NASA Astrophysics Data System (ADS)

Schreiber, Anders Ø.; Volovich, Anastasia; Zlotnikov, Michael

2018-06-01

Pasterski, Shao and Strominger have recently proposed that massless scattering amplitudes can be mapped to correlators on the celestial sphere at infinity via a Mellin transform. We apply this prescription to arbitrary n-point tree-level gluon amplitudes. The Mellin transforms of MHV amplitudes are given by generalized hypergeometric functions on the Grassmannian Gr (4 , n), while generic non-MHV amplitudes are given by more complicated Gelfand A-hypergeometric functions.

Measuring Angular Rate of Celestial Objects Using the Space Surveillance Telescope

DTIC Science & Technology

2015-03-01

is not subject to copyright protection in the United States. AFIT-ENG-MS-15-M-019 MEASURING ANGULAR RATE OF CELESTIAL OBJECTS USING THE SPACE ...Hypothesis Test MHTOR Multi-Hypothesis Test with Outlier Removal NEAs Near Earth Asteroids NASA National Aeronautics and Space Administration OTF...capabilities to warfighters, protecting them from collision with space debris, meteors and microsatellites has become a top priority [19]. In general, EO

Astronomy, Divination, and Politics in the Neo-Assyrian Empire

NASA Astrophysics Data System (ADS)

Verderame, Lorenzo

Celestial divination had an important role in the complex political and military machine of the Neo-Assyrian empire. Thousand of cuneiform documents dealing with celestial divination have come to light from the excavated archives of this period, as the Assurbanipal's library. Among them letters and reports enlight the relation of the king with his experts (ummânu), who performed divination and apotropaic rituals for his protection.

The Moon Illusion

NASA Astrophysics Data System (ADS)

Rees, W. G.

1986-06-01

The Moon illusion, or celestial illusion, is the illusion that the Moon near the horizon is larger than the Moon near the zenith, usually by a factor of about 2 in the diameter. The illusion has been known for over 2,000 years, and many explanations have been advanced for it. Four modern theories are discussed in this paper, and new data are presented which tend to confirm the common 'flattened celestial vault' hypothesis.

Obliquity of the Ecliptic

NASA Astrophysics Data System (ADS)

Murdin, P.

2000-11-01

The angle between the planes of the ecliptic and the equator. On the celestial sphere, the angle at which the ecliptic intersects the celestial equator. The current (year 2000) value of the obliquity of ecliptic, which is denoted by the symbol ɛ, is 23° 26' 21''. Its value varies by ±9'' over a period of 18.6 years as a consequence of a phenomenon called nutation. Over a much longer period (abou...

Correlation analysis of 1 to 30 MeV celestial gamma rays

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

Long, J.L.

1984-01-01

This paper outlines the development of a method of producing celestial sky maps from the data generated by the University of California, Riverside's double Compton scatter gamma ray telescope. The method makes use of a correlation between the telescope's data and theoretical calculated response functions. The results of applying this technique to northern hemisphere data obtained from a 1978 balloon flight from Palestine, Texas are included.

Killer rocks and the celestial police - The search for near-earth asteroids

NASA Technical Reports Server (NTRS)

Yeomans, Donald K.

1991-01-01

The discovery of asteroids near the earth as the result of search programs is detailed with attention given to methods for locating, tracking, and identifying asteroids. The concept of 'prediscovery' is discussed in which new asteroids are tracked backward in time through previous celestial observational data. The need for more comprehensive programs is identified in order to locate objects that present a clear danger of colliding with the earth.

General-relativistic celestial mechanics. 4: Theory of satellite motion

NASA Astrophysics Data System (ADS)

Damour, T.; Soffel, M.; Xu, C.

1993-09-01

The basic equations needed for developing a complete relativistic theory of artificial Earth satellites are explicitly written down. These equations are given both in a local, geocentric frame and in the global, barycentric one. They are derived within our recently introduced general-relativistic celestial mechanics framework. Our approach is more satisfactory than previous ones, especially with regard to its consistency, completeness, and flexibility. In particular, the problem of representing the relativistic gravitational effects associated with the quadrupole and higher multipole moments of the moving Earth, which caused difficulties in several other approaches, is easily dealth with in our approach, thanks to the use of previously developed tools: definition of relativistic multipole moments and transformation theory between reference frames. With this last paper in a series, we hope to indicate the way of using our formalism in specific problems in applied celestial mechanics and astrometry.

Polynomial equations for science orbits around Europa

NASA Astrophysics Data System (ADS)

Cinelli, Marco; Circi, Christian; Ortore, Emiliano

2015-07-01

In this paper, the design of science orbits for the observation of a celestial body has been carried out using polynomial equations. The effects related to the main zonal harmonics of the celestial body and the perturbation deriving from the presence of a third celestial body have been taken into account. The third body describes a circular and equatorial orbit with respect to the primary body and, for its disturbing potential, an expansion in Legendre polynomials up to the second order has been considered. These polynomial equations allow the determination of science orbits around Jupiter's satellite Europa, where the third body gravitational attraction represents one of the main forces influencing the motion of an orbiting probe. Thus, the retrieved relationships have been applied to this moon and periodic sun-synchronous and multi-sun-synchronous orbits have been determined. Finally, numerical simulations have been carried out to validate the analytical results.

Infrared radiation scene generation of stars and planets in celestial background

NASA Astrophysics Data System (ADS)

Guo, Feng; Hong, Yaohui; Xu, Xiaojian

2014-10-01

An infrared (IR) radiation generation model of stars and planets in celestial background is proposed in this paper. Cohen's spectral template1 is modified for high spectral resolution and accuracy. Based on the improved spectral template for stars and the blackbody assumption for planets, an IR radiation model is developed which is able to generate the celestial IR background for stars and planets appearing in sensor's field of view (FOV) for specified observing date and time, location, viewpoint and spectral band over 1.2μm ~ 35μm. In the current model, the initial locations of stars are calculated based on midcourse space experiment (MSX) IR astronomical catalogue (MSX-IRAC) 2 , while the initial locations of planets are calculated using secular variations of the planetary orbits (VSOP) theory. Simulation results show that the new IR radiation model has higher resolution and accuracy than common model.

Nonlinear Uncertainty Propagation of Satellite State Error for Tracking and Conjunction Risk Assessment

DTIC Science & Technology

2017-12-18

Determination on Orbital Element Representations,” Celestial Mechanics and Dynamical Astronomy , Vol. 118, pp.165-195, 2014. [8] R. Weisman, M. Jah...Nonlinear Filtering,” Celestial Mechanics and Dynamical Astronomy , Vol. 118, pp.129-164, 2014. [10] R. Weisman, M. Majji, K. Alfriend, “Analytic...Conference on Mathematics and Astronomy : A Joint Long Journey, American Institute of Physics, 10.1063/1.3506064, Madrid, Spain, 2009. [33] X.L. Xu, Y.Q

Surface Photometry of Celestial Sources from a Space Vehicle: Introduction and Observational Procedures*

PubMed Central

Roach, Franklin E.; Carroll, Benjamin; Aller, Lawrence H.; Smith, Leroi

1972-01-01

Diffuse celestial sources of relatively low surface brightness such as the Milky Way, zodiacal light, and gegenschein (or contre lumière) can be studied most reliably from above the earth's atmosphere with equipment flown in artificial satellites. We review the techniques used and some of the difficulties encountered in day-time observations from satellites by the use of a special photometer and polarimeter flown in the orbiting skylab observatory, OSO-6. PMID:16591970

Pulmonary Inflammatory Responses to Acute Meteorite Dust Exposures - Implications for Human Space Exploration

NASA Technical Reports Server (NTRS)

Harrington, A. D.; McCubbin, F. M.; Vander Kaaden, K. E.; Kaur, J.; Smirnov, A.; Galdanes, K.; Schoonen, M. A. A.; Chen, L. C.; Tsirka, S. E.; Gordon, T.

2018-01-01

New initiatives to send humans to Mars within the next few decades are illustrative of the resurgence of interest in space travel. However, as with all exploration, there are risks. The Human Research Roadmap developed by NASA identifies the Risk of Adverse Health and Performance Effects of Celestial Dust Exposure as an area of concern. Extended human exploration will further increase the probability of inadvertent and repeated exposures to celestial dusts.

Risk of Adverse Health and Performance Effects of Celestial Dust Exposure

NASA Technical Reports Server (NTRS)

Scully, Robert R.; Meyers, Valerie E.

2015-01-01

Crew members can be directly exposed to celestial dust in several ways. After crew members perform extravehicular activities (EVAs), they may introduce into the habitat dust that will have collected on spacesuits and boots. Cleaning of the suits between EVAs and changing of the Environmental Control Life Support System filters are other operations that could result in direct exposure to celestial dusts. In addition, if the spacesuits used in exploration missions abrade the skin, as current EVA suits have, then contact with these wounds would provide a source of exposure. Further, if celestial dusts gain access to a suit's interior, as was the case during the Apollo missions, the dust could serve as an additional source of abrasions or enhance suit-induced injuries. When a crew leaves the surface of a celestial body and returns to microgravity, the dust that is introduced into the return vehicle will "float," thus increasing the opportunity for ocular and respiratory injury. Because the features of the respirable fraction of lunar dusts indicate they could be toxic to humans, NASA conducted several studies utilizing lunar dust simulants and authentic lunar dust to determine the unique properties of lunar dust that affect physiology, assess the dermal and ocular irritancy of the dust, and establish a permissible exposure limit for episodic exposure to airborne lunar dust during missions that would involve no more than 6 months stay on the lunar surface. Studies, with authentic lunar soils from both highland (Apollo 16) and mare (Apollo17) regions demonstrated that the lunar soil is highly abrasive to a high fidelity model of human skin. Studies of lunar dust returned during the Apollo 14 mission from an area of the moon in which the soils were comprised of mineral constituents from both major geological regions (highlands and mares regions) demonstrated only minimal ocular irritancy, and pulmonary toxicity that was less than the highly toxic terrestrial crystalline silica (Permissible Exposure Limit [PEL] 0.05 mg/m3) but more toxic than the nuisance dust titanium dioxide (TiO2 [PEL 5.0 mg/m3]). A PEL for episodic exposure to airborne lunar dust during a six-month stay on the lunar surface was established, in consultation with an independent, extramural panel of expert pulmonary toxicologists, at 0.3 mg/m3. The PEL provided for lunar dust is limited to the conditions and exposure specified therefore additional research remains to be accomplished with lunar dust to further address the issues of activation, address other areas of more unique lunar geology (Glotch et al., 2010; Greenhagen et al., 2010), examine potential toxicological effects of inhaled or ingested dust upon other organ systems, such cardiovascular, nervous systems, and examine effects of acute exposure to massive doses of dust such as may occur during off-nominal situations. Work to support the establishment of PELs for Martian dust and dusts of asteroids remains to be accomplished. The literature that describes health effects of exposure to toxic terrestrial dusts provides substantial basis for concern that prolonged exposure to respirable celestial dust could be detrimental to human health. Celestial bodies where a substantial portion of the dust is in the respirable range or where the dusts have large reactive surface areas or contain transition metals or volatile organics, represent greater risks of adverse effects from exposure to the dust. It is possible that in addition to adverse effects to the respiratory system, inhalation and ingestion of celestial dusts could pose risks to other systems

Review on the Celestial Sphere Positioning of FITS Format Image Based on WCS and Research on General Visualization

NASA Astrophysics Data System (ADS)

Song, W. M.; Fan, D. W.; Su, L. Y.; Cui, C. Z.

2017-11-01

Calculating the coordinate parameters recorded in the form of key/value pairs in FITS (Flexible Image Transport System) header is the key to determine FITS images' position in the celestial system. As a result, it has great significance in researching the general process of calculating the coordinate parameters. By combining CCD related parameters of astronomical telescope (such as field, focal length, and celestial coordinates in optical axis, etc.), astronomical images recognition algorithm, and WCS (World Coordinate System) theory, the parameters can be calculated effectively. CCD parameters determine the scope of star catalogue, so that they can be used to build a reference star catalogue by the corresponding celestial region of astronomical images; Star pattern recognition completes the matching between the astronomical image and reference star catalogue, and obtains a table with a certain number of stars between CCD plane coordinates and their celestial coordinates for comparison; According to different projection of the sphere to the plane, WCS can build different transfer functions between these two coordinates, and the astronomical position of image pixels can be determined by the table's data we have worked before. FITS images are used to carry out scientific data transmission and analyze as a kind of mainstream data format, but only to be viewed, edited, and analyzed in the professional astronomy software. It decides the limitation of popular science education in astronomy. The realization of a general image visualization method is significant. FITS is converted to PNG or JPEG images firstly. The coordinate parameters in the FITS header are converted to metadata in the form of AVM (Astronomy Visualization Metadata), and then the metadata is added to the PNG or JPEG header. This method can meet amateur astronomers' general needs of viewing and analyzing astronomical images in the non-astronomical software platform. The overall design flow is realized through the java program and tested by SExtractor, WorldWide Telescope, picture viewer, and other software.

Celestial Software Scratches More Than the Surface

NASA Technical Reports Server (NTRS)

2005-01-01

While NASA is preparing to send humans back to the Moon by 2020 and then eventually to Mars, the average person can explore the landscapes of these celestial bodies much sooner, without the risk and training, and without even leaving the comfort of home. Geological data and imagery collected from NASA missions are enabling anybody with computer access to virtually follow the footsteps of Apollo astronauts who walked on the Moon or trace the tracks of the exploration rovers currently on Mars.

Proceedings of the Symposium on Military Space Communications and Operations Held at USAF Academy, Colorado on 2-4 August 1983

DTIC Science & Technology

1983-08-04

IS CURRERTLY OFF; TRANSMITSTHE COM TO TURHE AN N; WAITS FO Procedures are valuable because they provide hCGMDTOTR PROPTION AN POCSSI OELAS...legal and Other Celestial Bodies ,!/ was a regime which has been created by brilliant accomplishment of the world international treaties. These legal...difficulty posed by some controversial provisions in the Agreement Governing the Activities of States on the Moon and Other Celestial Bodies and the

Expected Improvements in VLBI Measurements of the Earth's Orientation

NASA Technical Reports Server (NTRS)

Ma, Chopo

2003-01-01

Measurements of the Earth s orientation since the 1970s using space geodetic techniques have provided a continually expanding and improving data set for studies of the Earth s structure and the distribution of mass and angular momentum. The accuracy of current one-day measurements is better than 100 microarcsec for the motion of the pole with respect to the celestial and terrestrial reference frames and better than 3 microsec for the rotation around the pole. VLBI uniquely provides the three Earth orientation parameters (nutation and UTI) that relate the Earth to the extragalactic celestial reference frame. The accuracy and resolution of the VLBI Earth orientation time series can be expected to improve substantially in the near future because of refinements in the realization of the celestial reference frame, improved modeling of the troposphere and non-linear station motions, larger observing networks, optimized scheduling, deployment of disk-based Mark V recorders, full use of Mark IV capabilities, and e-VLBI. More radical future technical developments will be discussed.

Water in the trail of the Chelyabinsk bolide

NASA Astrophysics Data System (ADS)

Gladysheva, O. G.

2017-09-01

At 03:20 UTC on February 15, 2013 a very bright bolide entered Earth's atmosphere. Fragments of the meteorite fell to the earth's surface. Examination of these fragments revealed that several of them were located directly on the surface of the celestial body [1], while the majority lay at a depth of less than 2.5 m from the surface [2, 3]. The stone meteorite's durability, >15 MPa, corresponded to <1% of the initial mass, while the rest of the object possessed a low durability of 1 MPa [4]. Moreover, Fe3+ hydroxyls were discovered in meteorite samples, the formation of which required water [5]. The glow at the head of the bolide trail, lasting 8 seconds after the flight of the object, and the development of the cloud trail indicate that the celestial body carried water. The Chinese weather satellite Feng-Yun 2D discovered ice debris (water) in the bolide trail [6]. Here, we will demonstrate that the Chelyabinsk chondrite was delivered to the Earth by an ice-bearing celestial body.

Planetary cores, their energy flux relationship, and its implications

NASA Astrophysics Data System (ADS)

Johnson, Fred M.

2018-02-01

Integrated surface heat flux data from each planet in our solar system plus over 50 stars, including our Sun, was plotted against each object's known mass to generate a continuous exponential curve at an R-squared value of 0.99. The unexpected yet undeniable implication of this study is that all planets and celestial objects have a similar mode of energy production. It is widely accepted that proton-proton reactions require hydrogen gas at temperatures of about 15 million degrees, neither of which can plausibly exist inside a terrestrial planet. Hence, this paper proposes a nuclear fission mechanism for all luminous celestial objects, and uses this mechanism to further suggest a developmental narrative for all celestial bodies, including our Sun. This narrative was deduced from an exponential curve drawn adjacent to the first and passing through the Earth's solid core (as a known prototype). This trend line was used to predict the core masses for each planet as a function of its luminosity.

Connecting kinematic and dynamic reference frames by D-VLBI

NASA Astrophysics Data System (ADS)

Schuh, Harald; Plank, Lucia; Madzak, Matthias; Böhm, Johannes

2012-08-01

In geodetic and astrometric practice, terrestrial station coordinates are usually provided in the kinematic International Terrestrial Reference Frame (ITRF) and radio source coordinates in the International Celestial Reference Frame (ICRF), whereas measurements of space probes such as satellites and spacecrafts, or planetary ephemerides rest upon dynamical theories. To avoid inconsistencies and errors during measurement and calculation procedures, exact frame ties between quasi - inertial, kinematic and dynamic reference frames have to be secured. While the Earth Orientation Parameters (EOP), e.g. measured by VLBI, link the ITRF to the ICRF, the ties with the dynamic frames can be established with the differential Very Long Baseline Interferometry (D - VLBI) method. By observing space probes alternately t o radio sources, the relative position of the targets to each other on the sky can be determined with high accuracy. While D - VLBI is a common technique in astrophysics (source imaging) and deep space navigation, just recently there have been several effort s to use it for geodetic purposes. We present investigations concerning possible VLBI observations to satellites. This includes the potential usage of available GNNS satellites as well as specifically designed missions, as e.g. the GRASP mission proposed b y JPL/NASA and an international consortium, where the aspect of co - location in space of various techniques (VLBI, SLR, GNSS, DORIS) is the main focus.

Technology optimization techniques for multicomponent optical band-pass filter manufacturing

NASA Astrophysics Data System (ADS)

Baranov, Yuri P.; Gryaznov, Georgiy M.; Rodionov, Andrey Y.; Obrezkov, Andrey V.; Medvedev, Roman V.; Chivanov, Alexey N.

2016-04-01

Narrowband optical devices (like IR-sensing devices, celestial navigation systems, solar-blind UV-systems and many others) are one of the most fast-growing areas in optical manufacturing. However, signal strength in this type of applications is quite low and performance of devices depends on attenuation level of wavelengths out of operating range. Modern detectors (photodiodes, matrix detectors, photomultiplier tubes and others) usually do not have required selectivity or have higher sensitivity to background spectrum at worst. Manufacturing of a single component band-pass filter with high attenuation level of wavelength is resource-intensive task. Sometimes it's not possible to find solution for this problem using existing technologies. Different types of filters have technology variations of transmittance profile shape due to various production factors. At the same time there are multiple tasks with strict requirements for background spectrum attenuation in narrowband optical devices. For example, in solar-blind UV-system wavelengths above 290-300 nm must be attenuated by 180dB. In this paper techniques of multi-component optical band-pass filters assembly from multiple single elements with technology variations of transmittance profile shape for optimal signal-tonoise ratio (SNR) were proposed. Relationships between signal-to-noise ratio and different characteristics of transmittance profile shape were shown. Obtained practical results were in rather good agreement with our calculations.

The desert ant odometer: a stride integrator that accounts for stride length and walking speed.

PubMed

Wittlinger, Matthias; Wehner, Rüdiger; Wolf, Harald

2007-01-01

Desert ants, Cataglyphis, use path integration as a major means of navigation. Path integration requires measurement of two parameters, namely, direction and distance of travel. Directional information is provided by a celestial compass, whereas distance measurement is accomplished by a stride integrator, or pedometer. Here we examine the recently demonstrated pedometer function in more detail. By manipulating leg lengths in foraging desert ants we could also change their stride lengths. Ants with elongated legs ('stilts') or shortened legs ('stumps') take larger or shorter strides, respectively, and misgauge travel distance. Travel distance is overestimated by experimental animals walking on stilts, and underestimated by animals walking on stumps - strongly indicative of stride integrator function in distance measurement. High-speed video analysis was used to examine the actual changes in stride length, stride frequency and walking speed caused by the manipulations of leg length. Unexpectedly, quantitative characteristics of walking behaviour remained almost unaffected by imposed changes in leg length, demonstrating remarkable robustness of leg coordination and walking performance. These data further allowed normalisation of homing distances displayed by manipulated animals with regard to scaling and speed effects. The predicted changes in homing distance are in quantitative agreement with the experimental data, further supporting the pedometer hypothesis.

The polarization compass dominates over idiothetic cues in path integration of desert ants.

PubMed

Lebhardt, Fleur; Koch, Julja; Ronacher, Bernhard

2012-02-01

Desert ants, Cataglyphis, use the sky's pattern of polarized light as a compass reference for navigation. However, they do not fully exploit the complexity of this pattern, rather - as proposed previously - they assess their walking direction by means of an approximate solution based on a simplified internal template. Approximate rules are error-prone. We therefore asked whether the ants use additional cues to improve the accuracy of directional decisions, and focused on 'idiothetic' cues, i.e. cues based on information from proprioceptors. We trained ants in a channel system that was covered with a polarization filter, providing only a single e-vector direction as a directional 'celestial' cue. Then we observed their homebound runs on a test field, allowing full view of the sky. In crucial experiments, the ants were exposed to a cue conflict, in which sky compass and idiothetic information disagreed, by training them in a straight channel that provided a change in e-vector direction. The results indicated that the polarization information completely dominates over idiothetic cues. Two path segments with different e-vector orientations are combined linearly to a summed home vector. Our data provide additional evidence that Cataglyphis uses a simplified internal template to derive directional information from the sky's polarization pattern.

The AuScope geodetic VLBI array

NASA Astrophysics Data System (ADS)

Lovell, J. E. J.; McCallum, J. N.; Reid, P. B.; McCulloch, P. M.; Baynes, B. E.; Dickey, J. M.; Shabala, S. S.; Watson, C. S.; Titov, O.; Ruddick, R.; Twilley, R.; Reynolds, C.; Tingay, S. J.; Shield, P.; Adada, R.; Ellingsen, S. P.; Morgan, J. S.; Bignall, H. E.

2013-06-01

The AuScope geodetic Very Long Baseline Interferometry array consists of three new 12-m radio telescopes and a correlation facility in Australia. The telescopes at Hobart (Tasmania), Katherine (Northern Territory) and Yarragadee (Western Australia) are co-located with other space geodetic techniques including Global Navigation Satellite Systems (GNSS) and gravity infrastructure, and in the case of Yarragadee, satellite laser ranging (SLR) and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS) facilities. The correlation facility is based in Perth (Western Australia). This new facility will make significant contributions to improving the densification of the International Celestial Reference Frame in the Southern Hemisphere, and subsequently enhance the International Terrestrial Reference Frame through the ability to detect and mitigate systematic error. This, combined with the simultaneous densification of the GNSS network across Australia, will enable the improved measurement of intraplate deformation across the Australian tectonic plate. In this paper, we present a description of this new infrastructure and present some initial results, including telescope performance measurements and positions of the telescopes in the International Terrestrial Reference Frame. We show that this array is already capable of achieving centimetre precision over typical long-baselines and that network and reference source systematic effects must be further improved to reach the ambitious goals of VLBI2010.

Empirical corroboration of an earlier theoretical resolution to the UV paradox of insect polarized skylight orientation.

PubMed

Wang, Xin; Gao, Jun; Fan, Zhiguo

2014-02-01

It is surprising that many insect species use only the ultraviolet (UV) component of the polarized skylight for orientation and navigation purposes, while both the intensity and the degree of polarization of light from the clear sky are lower in the UV than at longer (blue, green, red) wavelengths. Why have these insects chosen the UV part of the polarized skylight? This strange phenomenon is called the "UV-sky-pol paradox". Although earlier several speculations tried to resolve this paradox, they did this without any quantitative data. A theoretical and computational model has convincingly explained why it is advantageous for certain animals to detect celestial polarization in the UV. We performed a sky-polarimetric approach and built a polarized skylight sensor that models the processing of polarization signals by insect photoreceptors. Using this model sensor, we carried out measurements under clear and cloudy sky conditions. Our results showed that light from the cloudy sky has maximal degree of polarization in the UV. Furthermore, under both clear and cloudy skies the angle of polarization of skylight can be detected with a higher accuracy. By this, we corroborated empirically the soundness of the earlier computational resolution of the UV-sky-pol paradox.

Flying Drosophila orient to sky polarization.

PubMed

Weir, Peter T; Dickinson, Michael H

2012-01-10

Insects maintain a constant bearing across a wide range of spatial scales. Monarch butterflies and locusts traverse continents [1, 2], and foraging bees and ants travel hundreds of meters to return to their nests [1, 3, 4], whereas many other insects fly straight for only a few centimeters before changing direction. Despite this variation in spatial scale, the brain region thought to underlie long-distance navigation is remarkably conserved [5, 6], suggesting that the use of a celestial compass is a general and perhaps ancient capability of insects. Laboratory studies of Drosophila have identified a local search mode in which short, straight segments are interspersed with rapid turns [7, 8]. However, this flight mode is inconsistent with measured gene flow between geographically separated populations [9-11], and individual Drosophila can travel 10 km across desert terrain in a single night [9, 12, 13]-a feat that would be impossible without prolonged periods of straight flight. To directly examine orientation behavior under outdoor conditions, we built a portable flight arena in which a fly viewed the natural sky through a liquid crystal device that could experimentally rotate the polarization angle. Our findings indicate that Drosophila actively orient using the sky's natural polarization pattern. Copyright © 2012 Elsevier Ltd. All rights reserved.

Small Body Exploration Technologies as Precursors for Interstellar Robotics

NASA Astrophysics Data System (ADS)

Noble, R. J.; Sykes, M. V.

The scientific activities undertaken to explore our Solar System will be very similar to those required someday at other stars. The systematic exploration of primitive small bodies throughout our Solar System requires new technologies for autonomous robotic spacecraft. These diverse celestial bodies contain clues to the early stages of the Solar System's evolution, as well as information about the origin and transport of water-rich and organic material, the essential building blocks for life. They will be among the first objects studied at distant star systems. The technologies developed to address small body and outer planet exploration will form much of the technical basis for designing interstellar robotic explorers. The Small Bodies Assessment Group, which reports to NASA, initiated a Technology Forum in 2011 that brought together scientists and technologists to discuss the needs and opportunities for small body robotic exploration in the Solar System. Presentations and discussions occurred in the areas of mission and spacecraft design, electric power, propulsion, avionics, communications, autonomous navigation, remote sensing and surface instruments, sampling, intelligent event recognition, and command and sequencing software. In this paper, the major technology themes from the Technology Forum are reviewed, and suggestions are made for developments that will have the largest impact on realizing autonomous robotic vehicles capable of exploring other star systems.

Empirical corroboration of an earlier theoretical resolution to the UV paradox of insect polarized skylight orientation

NASA Astrophysics Data System (ADS)

Wang, Xin; Gao, Jun; Fan, Zhiguo

2014-02-01

It is surprising that many insect species use only the ultraviolet (UV) component of the polarized skylight for orientation and navigation purposes, while both the intensity and the degree of polarization of light from the clear sky are lower in the UV than at longer (blue, green, red) wavelengths. Why have these insects chosen the UV part of the polarized skylight? This strange phenomenon is called the "UV-sky-pol paradox". Although earlier several speculations tried to resolve this paradox, they did this without any quantitative data. A theoretical and computational model has convincingly explained why it is advantageous for certain animals to detect celestial polarization in the UV. We performed a sky-polarimetric approach and built a polarized skylight sensor that models the processing of polarization signals by insect photoreceptors. Using this model sensor, we carried out measurements under clear and cloudy sky conditions. Our results showed that light from the cloudy sky has maximal degree of polarization in the UV. Furthermore, under both clear and cloudy skies the angle of polarization of skylight can be detected with a higher accuracy. By this, we corroborated empirically the soundness of the earlier computational resolution of the UV-sky-pol paradox.

A stereo-vision hazard-detection algorithm to increase planetary lander autonomy

NASA Astrophysics Data System (ADS)

Woicke, Svenja; Mooij, Erwin

2016-05-01

For future landings on any celestial body, increasing the lander autonomy as well as decreasing risk are primary objectives. Both risk reduction and an increase in autonomy can be achieved by including hazard detection and avoidance in the guidance, navigation, and control loop. One of the main challenges in hazard detection and avoidance is the reconstruction of accurate elevation models, as well as slope and roughness maps. Multiple methods for acquiring the inputs for hazard maps are available. The main distinction can be made between active and passive methods. Passive methods (cameras) have budgetary advantages compared to active sensors (radar, light detection and ranging). However, it is necessary to proof that these methods deliver sufficiently good maps. Therefore, this paper discusses hazard detection using stereo vision. To facilitate a successful landing not more than 1% wrong detections (hazards that are not identified) are allowed. Based on a sensitivity analysis it was found that using a stereo set-up at a baseline of ≤ 2 m is feasible at altitudes of ≤ 200 m defining false positives of less than 1%. It was thus shown that stereo-based hazard detection is an effective means to decrease the landing risk and increase the lander autonomy. In conclusion, the proposed algorithm is a promising candidate for future landers.

Small Body Exploration Technologies as Precursors for Interstellar Robotics

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

Noble, Robert; /SLAC; Sykes, Mark V.

The scientific activities undertaken to explore our Solar System will be the same as required someday at other stars. The systematic exploration of primitive small bodies throughout our Solar System requires new technologies for autonomous robotic spacecraft. These diverse celestial bodies contain clues to the early stages of the Solar System's evolution as well as information about the origin and transport of water-rich and organic material, the essential building blocks for life. They will be among the first objects studied at distant star systems. The technologies developed to address small body and outer planet exploration will form much of themore » technical basis for designing interstellar robotic explorers. The Small Bodies Assessment Group, which reports to NASA, initiated a Technology Forum in 2011 that brought together scientists and technologists to discuss the needs and opportunities for small body robotic exploration in the Solar System. Presentations and discussions occurred in the areas of mission and spacecraft design, electric power, propulsion, avionics, communications, autonomous navigation, remote sensing and surface instruments, sampling, intelligent event recognition, and command and sequencing software. In this paper, the major technology themes from the Technology Forum are reviewed, and suggestions are made for developments that will have the largest impact on realizing autonomous robotic vehicles capable of exploring other star systems.« less

KSC-98pc1191

NASA Image and Video Library

1998-09-30

KENNEDY SPACE CENTER, FLA. -- Deep Space 1 is lifted from its work platform, giving a closer view of the experimental solar-powered ion propulsion engine. The ion propulsion engine is the first non-chemical propulsion to be used as the primary means of propelling a spacecraft. Above the engine is one of the two solar wings, folded for launch, that will provide the power for it. When fully extended, the wings measure 38.6 feet from tip to tip. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Another onboard experiment includes software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, Cape Canaveral Air Station, in October. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches

KSC-98pc1189

NASA Image and Video Library

1998-09-30

KENNEDY SPACE CENTER, FLA. -- Deep Space 1 rests on its work platform after being fitted with thermal insulation. The reflective insulation is designed to protect the spacecraft as this side faces the sun. At either side of the spacecraft are its solar wings, folded for launch. When fully extended, the wings measure 38.6 feet from tip to tip. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include a solar-powered ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. The ion propulsion engine is the first non-chemical propulsion to be used as the primary means of propelling a spacecraft. Deep Space 1 will complete most of its mission objectives within the first two months, but may also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, Cape Canaveral Air Station, in October. Delta II rockets are medium capacity expendable launch vehicles derived from the Delta family of rockets built and launched since 1960. Since then there have been more than 245 Delta launches

The remarkable visual capacities of nocturnal insects: vision at the limits with small eyes and tiny brains

PubMed Central

2017-01-01

Nocturnal insects have evolved remarkable visual capacities, despite small eyes and tiny brains. They can see colour, control flight and land, react to faint movements in their environment, navigate using dim celestial cues and find their way home after a long and tortuous foraging trip using learned visual landmarks. These impressive visual abilities occur at light levels when only a trickle of photons are being absorbed by each photoreceptor, begging the question of how the visual system nonetheless generates the reliable signals needed to steer behaviour. In this review, I attempt to provide an answer to this question. Part of the answer lies in their compound eyes, which maximize light capture. Part lies in the slow responses and high gains of their photoreceptors, which improve the reliability of visual signals. And a very large part lies in the spatial and temporal summation of these signals in the optic lobe, a strategy that substantially enhances contrast sensitivity in dim light and allows nocturnal insects to see a brighter world, albeit a slower and coarser one. What is abundantly clear, however, is that during their evolution insects have overcome several serious potential visual limitations, endowing them with truly extraordinary night vision. This article is part of the themed issue ‘Vision in dim light’. PMID:28193808

Automatic readout micrometer

DOEpatents

Lauritzen, Ted

1982-01-01

A measuring system is disclosed for surveying and very accurately positioning objects with respect to a reference line. A principal use of this surveying system is for accurately aligning the electromagnets which direct a particle beam emitted from a particle accelerator. Prior art surveying systems require highly skilled surveyors. Prior art systems include, for example, optical surveying systems which are susceptible to operator reading errors, and celestial navigation-type surveying systems, with their inherent complexities. The present invention provides an automatic readout micrometer which can very accurately measure distances. The invention has a simplicity of operation which practically eliminates the possibilities of operator optical reading error, owning to the elimination of traditional optical alignments for making measurements. The invention has an extendable arm which carries a laser surveying target. The extendable arm can be continuously positioned over its entire length of travel by either a coarse or fine adjustment without having the fine adjustment outrun the coarse adjustment until a reference laser beam is centered on the target as indicated by a digital readout. The length of the micrometer can then be accurately and automatically read by a computer and compared with a standardized set of alignment measurements. Due to its construction, the micrometer eliminates any errors due to temperature changes when the system is operated within a standard operating temperature range.

Automatic readout micrometer

DOEpatents

Lauritzen, T.

A measuring system is described for surveying and very accurately positioning objects with respect to a reference line. A principle use of this surveying system is for accurately aligning the electromagnets which direct a particle beam emitted from a particle accelerator. Prior art surveying systems require highly skilled surveyors. Prior art systems include, for example, optical surveying systems which are susceptible to operator reading errors, and celestial navigation-type surveying systems, with their inherent complexities. The present invention provides an automatic readout micrometer which can very accurately measure distances. The invention has a simplicity of operation which practically eliminates the possibilities of operator optical reading error, owning to the elimination of traditional optical alignments for making measurements. The invention has an extendable arm which carries a laser surveying target. The extendable arm can be continuously positioned over its entire length of travel by either a coarse of fine adjustment without having the fine adjustment outrun the coarse adjustment until a reference laser beam is centered on the target as indicated by a digital readout. The length of the micrometer can then be accurately and automatically read by a computer and compared with a standardized set of alignment measurements. Due to its construction, the micrometer eliminates any errors due to temperature changes when the system is operated within a standard operating temperature range.