Teach and Touch the Earth and Sky

NASA Astrophysics Data System (ADS)

Florina Tendea, Camelia

2017-04-01

My name is Camelia Florina Tendea. I am primary school teacher at "Horea, Closca and Crisan" Secondary School, in Brad, a town in the west side of Transylvania. I am permanently interested to develop my knowledge and teaching skills about space sciences (Earth and Sky) because the new generations of students are very well informed and couriouse about these topics. In this context the teachers must be prepared to deal with such requests in school. Introducing of activity: For a primary school teacher is a real challenge teaching about Earth and Sky, so I consider that a collaboration with science teachers, engineers and other specialists in the sciences is absolutely essential and beneficial in the educational design. In my opinion, the contents about Earth ans Sky-Space in a single word- are very attractive for students and they are a permanent source of discoveries and provide a multidisciplinary vision, so required in the education. Possible contents to teach in primary school: about Earth: -Terra -the third Planet from the Sun; How Earth spins; Land and water; The Earth seen from space, Trip between Earth and Moon,Weather Phenomena; the Poles; about Sky: Solar System, Asteroids, Comets, Meteorites; Rosetta Mission or rendez-vous with a comet; Sun.Moon. Earth. Eclipse;Light Pollution and protection of the night sky; Life in Space. Astronauts and experiences; Mission X:- Train Like an Astronaut;About ISS. For teachers it is important to know from the beginning how they teach, a viable support is the teaching of STEM subjects, which provides access to careers in astronomy, science/technology space. We could teach about earth and sky using different kinds of experiments, simulations, hands-on activities, competitions, exhibitions, video presentations. Competences developed in primary school through these contents: Comunication, individual studying, understanding and valorisation of scientific information, relating to the natural environment. In addition, they are supplemented attitudes and behaviors that care for their health, for the health of others and to the natural environment, interest and appreciation of logical argument; curiosity and concern about environmental phenomena, independent thinking, creativity. I think that is very important, like teacher, to combine the two parts of teaching: theoretical one and practical one. TEACH means setting a bag of theoretical aspects and also who can provide us support?(ideas, resources, scientific competitions etc.) and TOUCH means practical aspects for teachers & students. Resoults: Participating of teachers and students at workshops, round table, scientific debates provide knowledge about Space in context of STEM disciplines, Hands-on experiences; Find different situations of learning; Ideas, methods and techniques for design new lessons; Real scientific data from ESA/ESERO/ROSA sites; Chance to be part of international projects. Conclusions:Teach and Touch the Earth and Sky - could be a great chance to benefit from the proposed programs of ESA, through which space can be brought into the classroom and used as a tool for teaching and learning, moreover access to actual scientific data and experiences shared by the scientists, or other specialists offers a new prespective in the study of STEM subjects by students.

Fire in the Sky--From Big Bang to Big Money: Outdoor Education and Sustainable Development. Part One.

ERIC Educational Resources Information Center

Walker, Rod

1998-01-01

Within diverse outdoor educational activities, a core experience of connection with the earth balances self, others, and nature with elements of ritual. Most effective when experiential, integrated, and technologically simple, the core experience's educative power lies in awakening awareness of interconnectedness between human and nonhuman life.…

Motion induced second order temperature and y-type anisotropies after the subtraction of linear dipole in the CMB maps

NASA Astrophysics Data System (ADS)

Sunyaev, Rashid A.; Khatri, Rishi

2013-03-01

y-type spectral distortions of the cosmic microwave background allow us to detect clusters and groups of galaxies, filaments of hot gas and the non-uniformities in the warm hot intergalactic medium. Several CMB experiments (on small areas of sky) and theoretical groups (for full sky) have recently published y-type distortion maps. We propose to search for two artificial hot spots in such y-type maps resulting from the incomplete subtraction of the effect of the motion induced dipole on the cosmic microwave background sky. This dipole introduces, at second order, additional temperature and y-distortion anisotropy on the sky of amplitude few μK which could potentially be measured by Planck HFI and Pixie experiments and can be used as a source of cross channel calibration by CMB experiments. This y-type distortion is present in every pixel and is not the result of averaging the whole sky. This distortion, calculated exactly from the known linear dipole, can be subtracted from the final y-type maps, if desired.

Motion induced second order temperature and y-type anisotropies after the subtraction of linear dipole in the CMB maps

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

Sunyaev, Rashid A.; Khatri, Rishi, E-mail: sunyaev@mpa-garching.mpg.de, E-mail: khatri@mpa-garching.mpg.de

2013-03-01

y-type spectral distortions of the cosmic microwave background allow us to detect clusters and groups of galaxies, filaments of hot gas and the non-uniformities in the warm hot intergalactic medium. Several CMB experiments (on small areas of sky) and theoretical groups (for full sky) have recently published y-type distortion maps. We propose to search for two artificial hot spots in such y-type maps resulting from the incomplete subtraction of the effect of the motion induced dipole on the cosmic microwave background sky. This dipole introduces, at second order, additional temperature and y-distortion anisotropy on the sky of amplitude few μKmore » which could potentially be measured by Planck HFI and Pixie experiments and can be used as a source of cross channel calibration by CMB experiments. This y-type distortion is present in every pixel and is not the result of averaging the whole sky. This distortion, calculated exactly from the known linear dipole, can be subtracted from the final y-type maps, if desired.« less

Outdoor chamber measurements of biological aerosols with a passive FTIR spectrometer

NASA Astrophysics Data System (ADS)

D'Amico, Francis M.; Emge, Darren K.; Roelant, Geoffrey J.

2004-02-01

Outdoor measurements of dry bacillus subtilis (BG) spores were conducted with a passive Fourier transform infrared (FTIR) spectrometer using two types of chambers. One was a large open-ended cell, and the other was a canyon of similar dimensions. The canyon exposes the aerosol plume to downwelling sky radiance, while the open-ended cell does not. The goal of the experiments was to develop a suitable test methodology for evaluation of passive standoff detectors for open-air aerosol measurements. Dry BG aerosol particles were dispersed with a blower through an opening in the side of the chamber to create a pseudo-stationary plume, wind conditions permitting. Numerous trials were performed with the FTIR spectrometer positioned to view mountain, sky and mixed mountain-sky backgrounds. This paper will discuss the results of the FTIR measurements for BG and Kaolin dust releases.

The VLITE Post-Processing Pipeline

NASA Astrophysics Data System (ADS)

Richards, Emily E.; Clarke, Tracy; Peters, Wendy; Polisensky, Emil; Kassim, Namir E.

2018-01-01

A post-processing pipeline to adaptively extract and catalog point sources is being developed to enhance the scientific value and accessibility of data products generated by the VLA Low-band Ionosphere and Transient Experiment (VLITE; ) on the Karl G. Jansky Very Large Array (VLA). In contrast to other radio sky surveys, the commensal observing mode of VLITE results in varying depths, sensitivities, and spatial resolutions across the sky based on the configuration of the VLA, location on the sky, and time on source specified by the primary observer for their independent science objectives. Therefore, previously developed tools and methods for generating source catalogs and survey statistics are not always appropriate for VLITE's diverse and growing set of data. A raw catalog of point sources extracted from every VLITE image will be created from source fit parameters stored in a queryable database. Point sources will be measured using the Python Blob Detector and Source Finder software (PyBDSF; Mohan & Rafferty 2015). Sources in the raw catalog will be associated with previous VLITE detections in a resolution- and sensitivity-dependent manner, and cross-matched to other radio sky surveys to aid in the detection of transient and variable sources. Final data products will include separate, tiered point source catalogs grouped by sensitivity limit and spatial resolution.

The GRB All-sky Spectrometer Experiment II: Data Collection and Analysis

NASA Astrophysics Data System (ADS)

Voigt, Elana; Martinot, Zachary; Banks, Zachary; Pober, Jonathan; Morales, Miguel F.

2015-01-01

The GRB All-sky Spectrometer Experiment (GASE) is a widefield interferometer radio telescope designed to look for Gamma Ray Bursts in the 30 to 50 MHz range. It is based and operated as a wholly undergraduate experiment at the University of Washington. This poster will focus on data analysis and the relation of data analysis to the commissioning process of our 8 element GASE array.

Velocity Distributions of Interplanetary Dust Derived from Astronomical Sky Spectra

NASA Astrophysics Data System (ADS)

Huestis, D. L.; Ali, S.; Cosby, P. C.; Slanger, T. G.

2001-11-01

Characterization of interplanetary dust is important for understanding the creation by accretion of planets and moons, the development of planetary atmospheres, and, potentially, for the initiation of prebiotic chemistry. The recent COBE mission has provided a profile in ecliptic coordinates of the distribution of interplanetary dust particles through their thermal infrared emission. Additional information about interplanetary dust can be extracted from its visible spectrum of scattered sunlight, called Zodiacal Light. Night sky spectra taken at large-aperture telescopes using high-resolution echelle spectrographs reveal Fraunhofer absorption features in the Zodiacal Light spectrum of scattered sunlight, a nuisance in subtraction from the spectrum of the extraterrestrial object under investigation. We are analyzing the intensity modulations and Doppler shifts of solar Fraunhofer absorption lines in the Zodiacal Light component of sky spectra, donated by collaborating astronomers using Keck/HIRES and other high-performance astronomical facilities. Our objectives include velocity distributions of interplanetary dust and improved separation of terrestrial and extraterrestrial sources in sky spectra. Participation of S. Ali was made possible by a grant from the NSF Physics Research Experiences for Undergraduates (REU) program.

The Ilgarijiri Project: A collaboration between Aboriginal communities and radio astronomers in the Murchison Region of Western Australia

NASA Astrophysics Data System (ADS)

Goldsmith, John

2014-07-01

The international radio astronomy initiative known as the Square Kilometre Array is a cutting-edge science project, aimed atdramatically expanding our vision and understanding of the Universe. The $2billion+ international project is being shared between Southern Africa and Australia. The Australian component, centred in the Murchison region of Western Australia, is based upon collaboration with Aboriginal communities. A collaborative project called "Ilgarijiri- Things Belonging to the Sky" shared scientific and Aboriginal knowledge of the night sky. Through a series of collaborative meetings and knowledge sharing, the Ilgarijiri project developed and showcased Aboriginal knowledge of the night sky, via an international touring Aboriginal art exhibition, in Australia, South Africa, the USA and Europe. The Aboriginal art exhibition presents Aboriginal stories relating to the night sky, which prominently feature the 'Seven Sisters' and the 'Emu', as well as the collaborative experience with radio astronomers. The success of the Ilgarijiri collaborative project is based upon several principles, which can help to inform and guide future cultural collaborative projects.

Feasibility of inverse problem solution for determination of city emission function from night sky radiance measurements

NASA Astrophysics Data System (ADS)

Petržala, Jaromír

2018-07-01

The knowledge of the emission function of a city is crucial for simulation of sky glow in its vicinity. The indirect methods to achieve this function from radiances measured over a part of the sky have been recently developed. In principle, such methods represent an ill-posed inverse problem. This paper deals with the theoretical feasibility study of various approaches to solving of given inverse problem. Particularly, it means testing of fitness of various stabilizing functionals within the Tikhonov's regularization. Further, the L-curve and generalized cross validation methods were investigated as indicators of an optimal regularization parameter. At first, we created the theoretical model for calculation of a sky spectral radiance in the form of a functional of an emission spectral radiance. Consequently, all the mentioned approaches were examined in numerical experiments with synthetical data generated for the fictitious city and loaded by random errors. The results demonstrate that the second order Tikhonov's regularization method together with regularization parameter choice by the L-curve maximum curvature criterion provide solutions which are in good agreement with the supposed model emission functions.

Sky Detection in Hazy Image.

PubMed

Song, Yingchao; Luo, Haibo; Ma, Junkai; Hui, Bin; Chang, Zheng

2018-04-01

Sky detection plays an essential role in various computer vision applications. Most existing sky detection approaches, being trained on ideal dataset, may lose efficacy when facing unfavorable conditions like the effects of weather and lighting conditions. In this paper, a novel algorithm for sky detection in hazy images is proposed from the perspective of probing the density of haze. We address the problem by an image segmentation and a region-level classification. To characterize the sky of hazy scenes, we unprecedentedly introduce several haze-relevant features that reflect the perceptual hazy density and the scene depth. Based on these features, the sky is separated by two imbalance SVM classifiers and a similarity measurement. Moreover, a sky dataset (named HazySky) with 500 annotated hazy images is built for model training and performance evaluation. To evaluate the performance of our method, we conducted extensive experiments both on our HazySky dataset and the SkyFinder dataset. The results demonstrate that our method performs better on the detection accuracy than previous methods, not only under hazy scenes, but also under other weather conditions.

Sky Detection in Hazy Image

PubMed Central

Song, Yingchao; Luo, Haibo; Ma, Junkai; Hui, Bin; Chang, Zheng

2018-01-01

Sky detection plays an essential role in various computer vision applications. Most existing sky detection approaches, being trained on ideal dataset, may lose efficacy when facing unfavorable conditions like the effects of weather and lighting conditions. In this paper, a novel algorithm for sky detection in hazy images is proposed from the perspective of probing the density of haze. We address the problem by an image segmentation and a region-level classification. To characterize the sky of hazy scenes, we unprecedentedly introduce several haze-relevant features that reflect the perceptual hazy density and the scene depth. Based on these features, the sky is separated by two imbalance SVM classifiers and a similarity measurement. Moreover, a sky dataset (named HazySky) with 500 annotated hazy images is built for model training and performance evaluation. To evaluate the performance of our method, we conducted extensive experiments both on our HazySky dataset and the SkyFinder dataset. The results demonstrate that our method performs better on the detection accuracy than previous methods, not only under hazy scenes, but also under other weather conditions. PMID:29614778

Investigating Galactic Structure with COBE/DIRBE and Simulation

NASA Technical Reports Server (NTRS)

Cohen, Martin

1999-01-01

In this work I applied the current version of the SKY model of the point source sky to the interpretation of the diffuse all-sky emission observed by COBE/DIRBE (Cosmic Background Explorer Satellite/Diffuse Infrared Background Experiment). The goal was to refine the SKY model using the all-sky DIRBE maps of the Galaxy, in order that a search could be made for an isotropic cosmic background."Faint Source Model" [FSM] was constructed to remove Galactic fore ground stars from the ZSMA products. The FSM mimics SKY version 1 but it was inadequate to seek cosmic background emission because of the sizeable residual emission in the ZSMA products after this starlight subtraction. At this point I can only support that such models are currently inadequate to reveal a cosmic background. Even SKY5 yields the same disappointing result.

Educating for the Preservation of Dark Skies

NASA Astrophysics Data System (ADS)

Preston, Sandra Lee; Cianciolo, Frank; Wetzel, Marc; Finkelstein, Keely; Wren, William; Nance, Craig

2015-08-01

The stars at night really are big and bright deep in the heart of Texas at the McDonald Observatory near Fort Davis, Texas. Each year 80,000 visitors from all over the world make the pilgrimage to the Observatory to attend one of the three-times-a-week star parties. Many experience, for the first time, the humbling, splendor of a truly dark night sky. Over the last several years, the Observatory has experienced dramatic increases in visitation demonstrating the public’s appetite for science education, in general, and interest in the night sky, in particular. This increasing interest in astronomy is, ironically, occurring at a time when most of humanity’s skies are becoming increasingly light-polluted frustrating this natural interest. Dark skies and knowledgeable education and outreach staff are an important resource in maintaining the public’s interest in astronomy, support for astronomical research, and local tourism.This year Observatory educators were inspired by the observance of the International Year of Light to promote healthy outdoor lighting through its popular Astronomy Day distance learning program. This program reaches tens of thousands of K-12 students in Texas and other states with a message of how they can take action to preserve dark skies. As well, more than a thousand Boy Scouts visiting during the summer months receive a special program, which includes activities focusing on good lighting practices, thereby earning them credits toward an astronomy badge.The Observatory also offers a half-a-dozen K-12 teacher professional development workshops onsite each year, which provide about 90 teachers with dark skies information, best-practice lighting demonstrations, and red flashlights. Multi-year workshops for National Park and State of Texas Parks personnel are offered on dark sky preservation and sky interpretation at McDonald and a Dark Skies fund for retrofitting lights in the surrounding area has been established. The Observatory also uses social media to post videos of eclipses and other celestial events that help non-astronomers remember how important it is to protect our dark skies.

Shared Skies Partnership: A Dual-Site All-Sky Live Remote Observing Initiative for Research and Education

NASA Astrophysics Data System (ADS)

Kielkopf, John F.; Hart, R.; Carter, B.; Collins, K. A.; Brown, C.; Hay, J.; Hons, A.; Marsden, S.

2014-01-01

The University of Southern Queensland's Mt. Kent Observatory in Queensland, Australia, and the University of Louisville's Moore Observatory in Kentucky, USA, are collaborating in the development of live remote observing for research, student training, and education. With a focus on flexible operation assisted by semi-autonomous controllers, rather than completely robotic data acquisition, the partnership provides interactive hands-on experience to students at all levels, optimized performance based on real-time observations, and flexible scheduling for transient events and targets of opportunity. Two sites on opposites sides of the globe cover the entire sky, and for equatorial regions allow nearly continuous coverage. The facilites include 0.5-m corrected Dall-Kirkham (CDK) telescopes at both sites, a 0.6 m Ritchie-Chretien telescope at Moore, and a new Nasmyth design 0.7-meter CDK at Mt. Kent instrumented for milli-magnitude precision photometry and wide field imaging, with spectrographs under development. We will describe the operational and data acquisition software, recent research results, and how remote access is being made available to students and observers.

Night Sky Weather Monitoring System Using Fish-Eye CCD

NASA Astrophysics Data System (ADS)

Tomida, Takayuki; Saito, Yasunori; Nakamura, Ryo; Yamazaki, Katsuya

Telescope Array (TA) is international joint experiment observing ultra-high energy cosmic rays. TA employs fluorescence detection technique to observe cosmic rays. In this technique, tho existence of cloud significantly affects quality of data. Therefore, cloud monitoring provides important information. We are developing two new methods for evaluating night sky weather with pictures taken by charge-coupled device (CCD) camera. One is evaluating the amount of cloud with pixels brightness. The other is counting the number of stars with contour detection technique. The results of these methods show clear correlation, and we concluded both the analyses are reasonable methods for weather monitoring. We discuss reliability of the star counting method.

Aerosol, Cloud and Trace Gas Observations Derived from Airborne Hyperspectral Radiance and Direct Beam Measurements in Recent Field Campaigns

NASA Technical Reports Server (NTRS)

Redemann, J.; Flynn, C. J.; Shinozuka, Y.; Kacenelenbogen, M.; Segal-Rosenheimer, M.; LeBlanc, S.; Russell, P. B.; Livingston, J. M.; Schmid, B.; Dunagan, S. E.;

A Novel Sky-Subtraction Method Based on Non-negative Matrix Factorisation with Sparsity for Multi-object Fibre Spectroscopy

NASA Astrophysics Data System (ADS)

Zhang, Bo; Zhang, Long; Ye, Zhongfu

2016-12-01

A novel sky-subtraction method based on non-negative matrix factorisation with sparsity is proposed in this paper. The proposed non-negative matrix factorisation with sparsity method is redesigned for sky-subtraction considering the characteristics of the skylights. It has two constraint terms, one for sparsity and the other for homogeneity. Different from the standard sky-subtraction techniques, such as the B-spline curve fitting methods and the Principal Components Analysis approaches, sky-subtraction based on non-negative matrix factorisation with sparsity method has higher accuracy and flexibility. The non-negative matrix factorisation with sparsity method has research value for the sky-subtraction on multi-object fibre spectroscopic telescope surveys. To demonstrate the effectiveness and superiority of the proposed algorithm, experiments are performed on Large Sky Area Multi-Object Fiber Spectroscopic Telescope data, as the mechanisms of the multi-object fibre spectroscopic telescopes are similar.

The History and Legacy of BATSE

NASA Technical Reports Server (NTRS)

Fishman, Gerald J.

2012-01-01

The BATSE experiment on the Compton Gamma-ray Observatory was the first large detector system specifically designed for the study of gamma-ray bursts. The eight large-area detectors allowed full-sky coverage and were optimized to operate in the energy region of the peak emission of most GRBs. BATSE provided detailed observations of the temporal and spectral characteristics of large samples of GRBs, and it was the first experiment to provide rapid notifications of the coarse location of many them. It also provided strong evidence for the cosmological distances to GRBs through the observation of the sky distribution and intensity distribution of numerous GRBs. The large number of GRBs observed with the high- sensitivity BATSE detectors continues to provide a database of GRB spectral and temporal properties in the primary energy range of GRB emission that will likely not be exceeded for at least another decade. The origin and development of the BATSE experiment, some highlights from the mission and its continuing legacy are described in this paper.

Interference Control in Preschoolers: Factors Influencing Performance on the Day-Night Task

ERIC Educational Resources Information Center

Montgomery, Derek E.; Anderson, Maren; Uhl, Elizabeth

2008-01-01

Two experiments investigated preschoolers' interference control in variants of the day-night task. The day-night task involves instructing children across 16 trials to say the word "day" when viewing a card depicting a nighttime sky and to say "night" when shown a picture of the daytime sky. The purpose of the experiments was to investigate…

Methods of Engaging Preschool-age Children in Science Practices During Astronomy Activities

NASA Astrophysics Data System (ADS)

Plummer, J. D.

2015-11-01

Providing preschool children with science learning experiences may improve their later science literacy. Further, research shows that children are capable of engaging in the same kinds of scientific reasoning as adults. An initial step towards increasing the opportunities for children to engage in science is to improve our understanding of how to support children's engagement in the practices of science in astronomy. To this end, the My Sky Tonight project is developing and evaluating astronomy activities for informal science educators to use with young children. I have gathered video of a series of astronomy workshops that engaged preschool-age children with My Sky Tonight-developed activities. This paper describes features of these museum-based astronomy activities that supported young children in evidence-based science practices.

Does Flattened Sky Dome Reduces Perceived Moon Size

NASA Astrophysics Data System (ADS)

Toskovic, O.

2009-09-01

The aim of this study was to examine the Flattened sky dome model as an explanation of the Moon illusion. Two experiments were done, in a dark room, in which distribution of depth cues is the same towards horizon as towards zenith. In the first experiment 14 participants had the task to equalize the perceived distances of three stimuli in three directions (horizontal, tilted 45 degrees and vertical). In the second experiment 16 participants had the task to estimate the perceived sizes of three stimuli in the same three directions. For distance estimates we found differences among three directions in a way, that as the head tilts upwards, the perceived space is being elongated, which is the opposite to flattened sky dome. For size estimates we found no difference among the three directions.

ROTSE All-Sky Surveys for Variable Stars. I. Test Fields

NASA Astrophysics Data System (ADS)

Akerlof, C.; Amrose, S.; Balsano, R.; Bloch, J.; Casperson, D.; Fletcher, S.; Gisler, G.; Hills, J.; Kehoe, R.; Lee, B.; Marshall, S.; McKay, T.; Pawl, A.; Schaefer, J.; Szymanski, J.; Wren, J.

2000-04-01

The Robotic Optical Transient Search Experiment I (ROTSE-I) experiment has generated CCD photometry for the entire northern sky in two epochs nightly since 1998 March. These sky patrol data are a powerful resource for studies of astrophysical transients. As a demonstration project, we present first results of a search for periodic variable stars derived from ROTSE-I observations. Variable identification, period determination, and type classification are conducted via automatic algorithms. In a set of nine ROTSE-I sky patrol fields covering roughly 2000 deg2, we identify 1781 periodic variable stars with mean magnitudes between mv=10.0 and mv=15.5. About 90% of these objects are newly identified as variable. Examples of many familiar types are presented. All classifications for this study have been manually confirmed. The selection criteria for this analysis have been conservatively defined and are known to be biased against some variable classes. This preliminary study includes only 5.6% of the total ROTSE-I sky coverage, suggesting that the full ROTSE-I variable catalog will include more than 32,000 periodic variable stars.

The GRB All-sky Spectrometer Experiment I: Instrument Overview and Science Drivers

NASA Astrophysics Data System (ADS)

Martinot, Zachary; Voigt, Elana; Banks, Zachary; Pober, Jonathan; Morales, Miguel F.

2015-01-01

The GRB All-sky Spectrometer Experiment (GASE) is an experiment designed to detect low frequency highly dispersed radio emission in the afterglow of a GRB. The detection of such a signal could provide a probe of IGM density as well as the conditions near the source of a GRB. The instrument used is an eight-element array of dipole antennas located on the University of Washington campus. This poster will further elaborate the design of the instrument and its scientific goals.

Automated Meteor Detection by All-Sky Digital Camera Systems

NASA Astrophysics Data System (ADS)

Suk, Tomáš; Šimberová, Stanislava

2017-12-01

We have developed a set of methods to detect meteor light traces captured by all-sky CCD cameras. Operating at small automatic observatories (stations), these cameras create a network spread over a large territory. Image data coming from these stations are merged in one central node. Since a vast amount of data is collected by the stations in a single night, robotic storage and analysis are essential to processing. The proposed methodology is adapted to data from a network of automatic stations equipped with digital fish-eye cameras and includes data capturing, preparation, pre-processing, analysis, and finally recognition of objects in time sequences. In our experiments we utilized real observed data from two stations.

Wild about Social Media and Technology?

NASA Astrophysics Data System (ADS)

Santascoy, S. J.

2011-09-01

It's tempting to jump on the social media bandwagon and insist your organization needs Facebook, twitter, etc. But, when funds are limited, social media and related publicity must be carefully thought out. The NASA Night Sky Network, which is managed by the Astronomical Society of the Pacific, has developed widgets for websites and blogs, an iPhone app, and a Facebook presence. This is all to attract, inform, and reach the next generation of amateur astronomers, with no additional work needed from the amateur astronomy community who are members of the Night Sky Network. Outreach professionals will gain valuable insight from our experience, and may replicate this model to design their own social media and technology plan.

"Between the Earth and the Skies" The Challenges to Catholic Institution-Building in Pennsylvania’s Croatian Communities, 1894-1924.

DTIC Science & Technology

1998-05-01

religious factors reveals points of divergence between their experience and that of other immigrant groups. An assimilation model developed by Silvano...Tomasi provides the framework for this comparison. The thesis concludes that several unique factors contributed to the anomalous religious

PySM: Python Sky Model

NASA Astrophysics Data System (ADS)

Thorne, Ben; Alonso, David; Naess, Sigurd; Dunkley, Jo

2017-04-01

PySM generates full-sky simulations of Galactic foregrounds in intensity and polarization relevant for CMB experiments. The components simulated are thermal dust, synchrotron, AME, free-free, and CMB at a given Nside, with an option to integrate over a top hat bandpass, to add white instrument noise, and to smooth with a given beam. PySM is based on the large-scale Galactic part of Planck Sky Model code and uses some of its inputs

Where is the sky?

NASA Astrophysics Data System (ADS)

Cohen, Ariel; Galili, Igal

2001-02-01

This paper discusses the origin of the concept of sky. It is shown to emerge from one's experience of the visual perception of nonluminous objects observed in/through the atmosphere during the daytime. The physical concept of visibility in the atmospheric environment underpins the perception of a flattened sky dome constructed by our mind. In addition, the Moon illusion receives a plausible explanation and both topics become appropriate for a conceptually oriented introduction course in physics and/or astronomy.

Evidence for a 17-day periodicity from Cyg-X-3

NASA Technical Reports Server (NTRS)

Holt, S. S.; Boldt, E. A.; Serlemitsos, P. J.; Kaluzienski, L. J.; Pravdo, S. H.; Peacock, A.; Elvis, M.; Watson, M. G.; Pounds, K. A.

1975-01-01

Data taken from the Ariel-5 All Sky Monitor and the Ariel-5 Sky Survey Experiment are analyzed. It is hypothesized that a periodicity of 17d is characteristic of CygX-3. Results of the analysis are given.

Spectral and Polarimetric Imagery Collection Experiment

DTIC Science & Technology

2011-12-01

meter Visibility Smoke, fog, haze Pyranometer Sun and sky radiation Pryheliometer Solar radiation direction Required tracking mount Distrometer(s... Pyranometers measure total sun and sky radiation. If the direction of the solar radiation is an important factor, then use of a normal incidence

Application of MIMO Techniques in sky-surface wave hybrid networking sea-state radar system

NASA Astrophysics Data System (ADS)

Zhang, L.; Wu, X.; Yue, X.; Liu, J.; Li, C.

2016-12-01

The sky-surface wave hybrid networking sea-state radar system contains of the sky wave transmission stations at different sites and several surface wave radar stations. The subject comes from the national 863 High-tech Project of China. The hybrid sky-surface wave system and the HF surface wave system work simultaneously and the HF surface wave radar (HFSWR) can work in multi-static and surface-wave networking mode. Compared with the single mode radar system, this system has advantages of better detection performance at the far ranges in ocean dynamics parameters inversion. We have applied multiple-input multiple-output(MIMO) techniques in this sea-state radar system. Based on the multiple channel and non-causal transmit beam-forming techniques, the MIMO radar architecture can reduce the size of the receiving antennas and simplify antenna installation. Besides, by efficiently utilizing the system's available degrees of freedom, it can provide a feasible approach for mitigating multipath effect and Doppler-spread clutter in Over-the-horizon Radar. In this radar, slow-time phase-coded MIMO method is used. The transmitting waveforms are phase-coded in slow-time so as to be orthogonal after Doppler processing at the receiver. So the MIMO method can be easily implemented without the need to modify the receiver hardware. After the radar system design, the MIMO experiments of this system have been completed by Wuhan University during 2015 and 2016. The experiment used Wuhan multi-channel ionospheric sounding system(WMISS) as sky-wave transmitting source and three dual-frequency HFSWR developed by the Oceanography Laboratory of Wuhan University. The transmitter system located at Chongyang with five element linear equi-spaced antenna array and Wuhan with one log-periodic antenna. The RF signals are generated by synchronized, but independent digital waveform generators - providing complete flexibility in element phase and amplitude control, and waveform type and parameters. The field experimental results show the presented method is effective. The echoes are obvious and distinguishable both in co-located MIMO mode and widely distributed MIMO mode. Key words: sky-surface wave hybrid networking; sea-state radar; MIMO; phase-coded

CUTIE: Cubesat Ultraviolet Transient Imaging Experiment

NASA Astrophysics Data System (ADS)

Cenko, Stephen B.; Bellm, Eric Christopher; Gal-Yam, Avishay; Gezari, Suvi; Gorjian, Varoujan; Jewell, April; Kruk, Jeffrey W.; Kulkarni, Shrinivas R.; Mushotzky, Richard; Nikzad, Shouleh; Piro, Anthony; Waxman, Eli; Ofek, Eran Oded

2017-01-01

We describe a mission concept for the Cubesat Ultraviolet Transient Imaging Experiment (CUTIE). CUTIE will image an area on the sky of ~ 1700 square degrees every ~ 95 min at near-UV wavelengths (260-320 nm) to a depth of 19.0 mag (AB). These capabilities represent orders of magnitude improvement over past UV imagers, allowing CUTIE to conduct the first true synoptic survey of the transient and variable sky in the UV bandpass. CUTIE will uniquely address key Decadal Survey science questions such as how massive stars end their lives, how super-massive black holes accrete material and influence their surroundings, and how suitable habitable-zone planets around low-mass stars are for hosting life. By partnering with upcoming ground-based time-domain surveys, CUTIE will further leverage its low-Earth orbit to provide a multi-wavelength view of the dynamic universe that can only be achieved from space. The remarkable sensitivity for such a small payload is achieved via the use of large format delta-doped CCDs; space qualifying this technology will serve as a key milestone towards the development of future large missions (Explorers and Surveyors). Finally, our innovative design in a 6U cubesat form factor will enable significant cost savings, accelerating the timeline from conception to on-sky operation (5 years; well matched for graduate student participation).

C-BASS: The C-Band All Sky Survey

NASA Astrophysics Data System (ADS)

Pearson, Timothy J.; C-BASS Collaboration

2016-06-01

The C-Band All Sky Survey (C-BASS) is a project to image the whole sky at a wavelength of 6 cm (frequency 5 GHz), measuring both the brightness and the polarization of the sky. Correlation polarimeters are mounted on two separate telescopes, one at the Owens Valley Observatory (OVRO) in California and another in South Africa, allowing C-BASS to map the whole sky. The OVRO instrument has completed observations for the northern part of the survey. We are working on final calibration of intensity and polarization. The southern instrument has recently started observations for the southern part of the survey from its site at Klerefontein near Carnarvon in South Africa. The principal aim of C-BASS is to allow the subtraction of polarized Galactic synchrotron emission from the data produced by CMB polarization experiments, such as WMAP, Planck, and dedicated B-mode polarization experiments. In addition it will contribute to studies of: (1) the local (< 1 kpc) Galactic magnetic field and cosmic-ray propagation; (2) the distribution of the anomalous dust emission, its origin and the physical processes that affect it; (3) modeling of Galactic total intensity emission, which may allow CMB experiments access to the currently inaccessible region close to the Galactic plane. Observations at many wavelengths from radio to infrared are needed to fully understand the foregrounds. At 5 GHz, C-BASS maps synchrotron polarization with minimal corruption by Faraday rotation, and complements the full-sky maps from WMAP and Planck. I will present the project status, show results of component separation in selected sky regions, and describe the northern survey data products.C-BASS (http://www.astro.caltech.edu/cbass/) is a collaborative project between the Universities of Oxford and Manchester in the UK, the California Institute of Technology (supported by the National Science Foundation and NASA) in the USA, the Hartebeesthoek Radio Astronomy Observatory (supported by the Square Kilometre Array project) in South Africa, and the King Abdulaziz City for Science and Technology (KACST) in Saudi Arabia.

Spectral and Polarimetric Imagery Collection Experiment

DTIC Science & Technology

2011-12-01

Also melted snow liquid rate Optical rain gauge Rain rate Possibly snow rate Visibility meter Visibility Smoke, fog, haze Pyranometer Sun and sky...performance of the IR imagery due to thermal effect or possible inversion layer effects. Pyranometers measure total sun and sky radiation. If the direction

In The Night Sky: Sky Lore.

ERIC Educational Resources Information Center

Judge, April

1997-01-01

Presents picture books, collections of star stories, poetry, magazines, radio programs, biographies, nonfiction, and activities to help young students (preschool-grade 8) understand what celestial objects meant to ancient civilizations and to provide insights into the customs and attitudes of other cultures; alternative literary experiences; and…

From Wisdom to Innocence: Passing on the Knowledge of the Night Sky

NASA Technical Reports Server (NTRS)

Shope, R.

1996-01-01

Memorable learning can happen when the whole family shares the thrill of discovery together. The fascination of the night sky presents a perfect opportunity for gifted parents and children to experience the tradition of passing on knowledge from generation to generation.

Ultra-Stable Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (5STAR)

NASA Technical Reports Server (NTRS)

Dunagan, Stephen E.; Johnson, Roy R.; Redemann, Jens; Holben, Brent N.; Schmidt, Beat; Flynn, Connor Joseph; Fahey, Lauren; LeBlanc, Samuel; Liss, Jordan; Kacenelenbogen, Meloe S.;

Evaluating the spatio-temporal performance of sky imager based solar irradiance analysis and forecasts

NASA Astrophysics Data System (ADS)

Schmidt, T.; Kalisch, J.; Lorenz, E.; Heinemann, D.

2015-10-01

Clouds are the dominant source of variability in surface solar radiation and uncertainty in its prediction. However, the increasing share of solar energy in the world-wide electric power supply increases the need for accurate solar radiation forecasts. In this work, we present results of a shortest-term global horizontal irradiance (GHI) forecast experiment based on hemispheric sky images. A two month dataset with images from one sky imager and high resolutive GHI measurements from 99 pyranometers distributed over 10 km by 12 km is used for validation. We developed a multi-step model and processed GHI forecasts up to 25 min with an update interval of 15 s. A cloud type classification is used to separate the time series in different cloud scenarios. Overall, the sky imager based forecasts do not outperform the reference persistence forecasts. Nevertheless, we find that analysis and forecast performance depend strongly on the predominant cloud conditions. Especially convective type clouds lead to high temporal and spatial GHI variability. For cumulus cloud conditions, the analysis error is found to be lower than that introduced by a single pyranometer if it is used representatively for the whole area in distances from the camera larger than 1-2 km. Moreover, forecast skill is much higher for these conditions compared to overcast or clear sky situations causing low GHI variability which is easier to predict by persistence. In order to generalize the cloud-induced forecast error, we identify a variability threshold indicating conditions with positive forecast skill.

Overview of Assistive Technology Possibilities for Teachers to Enhance Academic Outcomes of All Students

ERIC Educational Resources Information Center

Akpan, Joseph P.; Beard, Lawrence A.

2013-01-01

Despite enormous improvements in AT devices and services in American classrooms, the number of students with special needs, and the complexity of needs that they and their families experience continues to be sky rocketed nationwide. In response to these urgent needs, more advanced and specialized assistive technologies have been developed that…

Spectral atmospheric observations at Nantucket Island, May 7-14, 1981

NASA Technical Reports Server (NTRS)

Talay, T. A.; Poole, L. R.

1981-01-01

An experiment was conducted by the National Langley Research Center to measure atmospheric optical conditions using a 10-channel solar spectral photometer system. This experiment was part of a larger series of multidisciplinary experiments performed in the area of Nantucket Shoals aimed at studying the dynamics of phytoplankton production processes. Analysis of the collected atmospheric data yield total and aerosol optical depths, transmittances, normalized sky radiance distributions, and total and sky irradiances. Results of this analysis may aid in atmospheric corrections of remote sensor data obtained by several sensors overflying the Nantucket Shoals area. Recommendations are presented concerning future experiments using the described solar photometer system and calibration and operational deficiencies uncovered during the experiment.

All Sky Observations with BATSE and GBM

NASA Technical Reports Server (NTRS)

Wilson-Hodge, Colleen A.

2008-01-01

The Burst and Transient Source Experiment (BATSE) on board the Compton Gamma Ray Observatory (CGRO) monitored the entire sky from 1991-2000. I will review highlights of BATSE observations including gamma ray bursts, black hole candidates, accreting pulsars, and active galaxies. On 2008 June 11, the Fermi Gamma Ray Space Telescope was launched. The Gamma ray Burst Monitor (GBM) on board Fermi continues the all-sky monitoring legacy started with BATSE. I will review early results and planned observations with GBM.

Powerful model for the point source sky: Far-ultraviolet and enhanced midinfrared performance

NASA Technical Reports Server (NTRS)

Cohen, Martin

1994-01-01

I report further developments of the Wainscoat et al. (1992) model originally created for the point source infrared sky. The already detailed and realistic representation of the Galaxy (disk, spiral arms and local spur, molecular ring, bulge, spheroid) has been improved, guided by CO surveys of local molecular clouds, and by the inclusion of a component to represent Gould's Belt. The newest version of the model is very well validated by Infrared Astronomy Satellite (IRAS) source counts. A major new aspect is the extension of the same model down to the far ultraviolet. I compare predicted and observed far-utraviolet source counts from the Apollo 16 'S201' experiment (1400 A) and the TD1 satellite (for the 1565 A band).

Astronomy Software

NASA Technical Reports Server (NTRS)

1995-01-01

Software Bisque's TheSky, SkyPro and Remote Astronomy Software incorporate technology developed for the Hubble Space Telescope. TheSky and SkyPro work together to orchestrate locating, identifying and acquiring images of deep sky objects. With all three systems, the user can directly control computer-driven telescopes and charge coupled device (CCD) cameras through serial ports. Through the systems, astronomers and students can remotely operate a telescope at the Mount Wilson Observatory Institute.

Past climate change on Sky Islands drives novelty in a core developmental gene network and its phenotype.

PubMed

Favé, Marie-Julie; Johnson, Robert A; Cover, Stefan; Handschuh, Stephan; Metscher, Brian D; Müller, Gerd B; Gopalan, Shyamalika; Abouheif, Ehab

2015-09-04

A fundamental and enduring problem in evolutionary biology is to understand how populations differentiate in the wild, yet little is known about what role organismal development plays in this process. Organismal development integrates environmental inputs with the action of gene regulatory networks to generate the phenotype. Core developmental gene networks have been highly conserved for millions of years across all animals, and therefore, organismal development may bias variation available for selection to work on. Biased variation may facilitate repeatable phenotypic responses when exposed to similar environmental inputs and ecological changes. To gain a more complete understanding of population differentiation in the wild, we integrated evolutionary developmental biology with population genetics, morphology, paleoecology and ecology. This integration was made possible by studying how populations of the ant species Monomorium emersoni respond to climatic and ecological changes across five 'Sky Islands' in Arizona, which are mountain ranges separated by vast 'seas' of desert. Sky Islands represent a replicated natural experiment allowing us to determine how repeatable is the response of M. emersoni populations to climate and ecological changes at the phenotypic, developmental, and gene network levels. We show that a core developmental gene network and its phenotype has kept pace with ecological and climate change on each Sky Island over the last ~90,000 years before present (BP). This response has produced two types of evolutionary change within an ant species: one type is unpredictable and contingent on the pattern of isolation of Sky lsland populations by climate warming, resulting in slight changes in gene expression, organ growth, and morphology. The other type is predictable and deterministic, resulting in the repeated evolution of a novel wingless queen phenotype and its underlying gene network in response to habitat changes induced by climate warming. Our findings reveal dynamics of developmental gene network evolution in wild populations. This holds important implications: (1) for understanding how phenotypic novelty is generated in the wild; (2) for providing a possible bridge between micro- and macroevolution; and (3) for understanding how development mediates the response of organisms to past, and potentially, future climate change.

Can You See the Stars? Citizen-Science Programs to Measure Night Sky Brightness

NASA Astrophysics Data System (ADS)

Walker, Constance E.

2009-05-01

For the IYA2009 Dark Skies Awareness Cornerstone Project, partners in dark-sky, astronomy and environmental education are promoting three citizen-scientist programs that measure light pollution at local levels worldwide. These programs take the form of "star hunts", providing people with fun and direct ways to acquire heightened awareness about light pollution through first-hand observations of the night sky. Together the programs are spanning the entire IYA, namely: GLOBE at Night in March, Great World Wide Star Count in October, and How Many Stars during the rest of the year. Citizen-scientists - students, educators, amateur astronomers and the general public - measure the darkness of their local skies and contribute observations online to a world map. Anyone anywhere anytime can look within particular constellations for the faintest stars and match them to one of seven star maps. For more precise measurements, digital sky-brightness meters can be used. Measurements, along with the measurement location, time, and date, are submitted online, and within a few days to weeks a world map showing results is available. These measurements can be compared with data from previous years, as well as with satellite data, population densities, and electrical power-usage maps. Measurements are available online via Google Earth or other tools and as downloadable datasets. Data from multiple locations in one city or region are especially interesting, and can be used as the basis of a class project or science fair experiment, or even to inform the development of public policy. In the last few years these programs successfully conducted campaigns in which more than 35,000 observations were submitted from over 100 countries. The presentation will provide an update, describe how people can become involved and take a look ahead at the program's sustainability. For further information about these and other Dark Skies Awareness programs, please visit www.darkskiesawareness.org.

Dark Sky Collaborators: Arizona (AZ) Observatories, Communities, and Businesses

NASA Astrophysics Data System (ADS)

Del Castillo, Elizabeth Alvarez; Corbally, Christopher; Falco, Emilio E.; Green, Richard F.; Hall, Jeffrey C.; Williams, G. Grant

2015-03-01

With outdoor lighting ordinances in Arizona first in place around observatories in 1958 and 1972, then throughout the state since 1986, Arizonans have extensive experience working with communities and businesses to preserve our dark skies. Though communities are committed to the astronomy sector in our state, astronomers must collaborate with other stakeholders to implement solutions. Ongoing education and public outreach is necessary to enable ordinance updates as technology changes. Despite significant population increases, sky brightness measurements over the last 20 years show that ordinance updates are worth our efforts as we seek to maintain high quality skies around our observatories. Collaborations are being forged and actions taken to promote astronomy for the longer term in Arizona.

ultra-Stable Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (5STAR)

NASA Astrophysics Data System (ADS)

Dunagan, S. E.; Johnson, R. R.; Redemann, J.; Holben, B. N.; Schmid, B.; Flynn, C. J.; Fahey, L.; LeBlanc, S. E.; Liss, J.; Kacenelenbogen, M. S.; Segal-Rosenhaimer, M.; Shinozuka, Y.; Dahlgren, R. P.; Pistone, K.; Karol, Y.

2017-12-01

The Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) combines airborne sun tracking and sky scanning with diffraction spectroscopy to improve knowledge of atmospheric constituents and their links to air pollution and climate. Direct beam hyperspectral measurement of optical depth improves retrievals of gas constituents and determination of aerosol properties. Sky scanning enhances retrievals of aerosol type and size distribution. Hyperspectral cloud-transmitted radiance measurements enable the retrieval of cloud properties from below clouds. These measurements tighten the closure between satellite and ground-based measurements. 4STAR incorporates a modular sun-tracking/ sky-scanning optical head with optical fiber signal transmission to rack mounted spectrometers, permitting miniaturization of the external optical tracking head, and future detector evolution. 4STAR has supported a broad range of flight experiments since it was first flown in 2010. This experience provides the basis for a series of improvements directed toward reducing measurement uncertainty and calibration complexity, and expanding future measurement capabilities, to be incorporated into a new 5STAR instrument. A 9-channel photodiode radiometer with AERONET-matched bandpass filters will be incorporated to improve calibration stability. A wide dynamic range tracking camera will provide a high precision solar position tracking signal as well as an image of sky conditions around the solar axis. An ultrasonic window cleaning system design will be tested. A UV spectrometer tailored for formaldehyde and SO2 gas retrievals will be added to the spectrometer enclosure. Finally, expansion capability for a 4 channel polarized radiometer to measure the Stokes polarization vector of sky light will be incorporated. This paper presents initial progress on this next-generation 5STAR instrument. Keywords: atmosphere; climate; pollution; radiometry; technology; hyperspectral; fiber optic, polarimetry

Solar Resource Assessment with Sky Imagery and a Virtual Testbed for Sky Imager Solar Forecasting

NASA Astrophysics Data System (ADS)

Kurtz, Benjamin Bernard

In recent years, ground-based sky imagers have emerged as a promising tool for forecasting solar energy on short time scales (0 to 30 minutes ahead). Following the development of sky imager hardware and algorithms at UC San Diego, we present three new or improved algorithms for sky imager forecasting and forecast evaluation. First, we present an algorithm for measuring irradiance with a sky imager. Sky imager forecasts are often used in conjunction with other instruments for measuring irradiance, so this has the potential to decrease instrumentation costs and logistical complexity. In particular, the forecast algorithm itself often relies on knowledge of the current irradiance which can now be provided directly from the sky images. Irradiance measurements are accurate to within about 10%. Second, we demonstrate a virtual sky imager testbed that can be used for validating and enhancing the forecast algorithm. The testbed uses high-quality (but slow) simulations to produce virtual clouds and sky images. Because virtual cloud locations are known, much more advanced validation procedures are possible with the virtual testbed than with measured data. In this way, we are able to determine that camera geometry and non-uniform evolution of the cloud field are the two largest sources of forecast error. Finally, with the assistance of the virtual sky imager testbed, we develop improvements to the cloud advection model used for forecasting. The new advection schemes are 10-20% better at short time horizons.

The NASA SETI sky survey - Recent developments

NASA Technical Reports Server (NTRS)

Klein, Michael J.; Gulkis, Samuel; Olsen, Edward T.; Renzetti, Nicholas A.

1988-01-01

NASA's Search for Extraterrestrial Intelligence (SETI) project utilizes two complimentary search strategies: a sky survey and a targeted search. The SETI team at the Jet Propulsion Laboratory have primary responsibility to develop and carry out the sky survey part of the Microwave Observing Project. The paper describes progress that has been made to develop the major elements of the survey including a two-million channel wideband spectrum analyzer system that is being developed and constructed by JPL for the Deep Space Network. The new system will be a multiuser instrument that will serve as a prototype for the SETI Sky Survey processor. This system will be used to test the signal detection and observational strategies on deep-space network antennas in the near future.

The new world atlas of artificial night sky brightness

PubMed Central

Falchi, Fabio; Cinzano, Pierantonio; Duriscoe, Dan; Kyba, Christopher C. M.; Elvidge, Christopher D.; Baugh, Kimberly; Portnov, Boris A.; Rybnikova, Nataliya A.; Furgoni, Riccardo

2016-01-01

Artificial lights raise night sky luminance, creating the most visible effect of light pollution—artificial skyglow. Despite the increasing interest among scientists in fields such as ecology, astronomy, health care, and land-use planning, light pollution lacks a current quantification of its magnitude on a global scale. To overcome this, we present the world atlas of artificial sky luminance, computed with our light pollution propagation software using new high-resolution satellite data and new precision sky brightness measurements. This atlas shows that more than 80% of the world and more than 99% of the U.S. and European populations live under light-polluted skies. The Milky Way is hidden from more than one-third of humanity, including 60% of Europeans and nearly 80% of North Americans. Moreover, 23% of the world’s land surfaces between 75°N and 60°S, 88% of Europe, and almost half of the United States experience light-polluted nights. PMID:27386582

The new world atlas of artificial night sky brightness.

PubMed

Falchi, Fabio; Cinzano, Pierantonio; Duriscoe, Dan; Kyba, Christopher C M; Elvidge, Christopher D; Baugh, Kimberly; Portnov, Boris A; Rybnikova, Nataliya A; Furgoni, Riccardo

2016-06-01

Artificial lights raise night sky luminance, creating the most visible effect of light pollution-artificial skyglow. Despite the increasing interest among scientists in fields such as ecology, astronomy, health care, and land-use planning, light pollution lacks a current quantification of its magnitude on a global scale. To overcome this, we present the world atlas of artificial sky luminance, computed with our light pollution propagation software using new high-resolution satellite data and new precision sky brightness measurements. This atlas shows that more than 80% of the world and more than 99% of the U.S. and European populations live under light-polluted skies. The Milky Way is hidden from more than one-third of humanity, including 60% of Europeans and nearly 80% of North Americans. Moreover, 23% of the world's land surfaces between 75°N and 60°S, 88% of Europe, and almost half of the United States experience light-polluted nights.

Tropical rainforest response to marine sky brightening climate engineering

NASA Astrophysics Data System (ADS)

Muri, Helene; Niemeier, Ulrike; Kristjánsson, Jón Egill

2015-04-01

Tropical forests represent a major atmospheric carbon dioxide sink. Here the gross primary productivity (GPP) response of tropical rainforests to climate engineering via marine sky brightening under a future scenario is investigated in three Earth system models. The model response is diverse, and in two of the three models, the tropical GPP shows a decrease from the marine sky brightening climate engineering. Partial correlation analysis indicates precipitation to be important in one of those models, while precipitation and temperature are limiting factors in the other. One model experiences a reversal of its Amazon dieback under marine sky brightening. There, the strongest partial correlation of GPP is to temperature and incoming solar radiation at the surface. Carbon fertilization provides a higher future tropical rainforest GPP overall, both with and without climate engineering. Salt damage to plants and soils could be an important aspect of marine sky brightening.

Evaluation of Clear Sky Models for Satellite-Based Irradiance Estimates

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

Sengupta, Manajit; Gotseff, Peter

2013-12-01

This report describes an intercomparison of three popular broadband clear sky solar irradiance model results with measured data, as well as satellite-based model clear sky results compared to measured clear sky data. The authors conclude that one of the popular clear sky models (the Bird clear sky model developed by Richard Bird and Roland Hulstrom) could serve as a more accurate replacement for current satellite-model clear sky estimations. Additionally, the analysis of the model results with respect to model input parameters indicates that rather than climatological, annual, or monthly mean input data, higher-time-resolution input parameters improve the general clear skymore » model performance.« less

A hard X-ray experiment for long-duration balloon flights

NASA Astrophysics Data System (ADS)

Johnson, W. N.; Kurfess, J. D.; Strickman, M. S.; Saulnier, D. M.

The Naval Research Lab has developed a balloon-borne hard X-ray experiment which is designed for 60- to 90-day flight durations soon to be available with around the world Sky Anchor or RACOON balloon flights. The experiment's scintillation detector is sensitive to the 15 - 250 keV X-ray energy range. The experiment includes three microcomputer systems which control the data acquisition and provide the orientation and navigation information required for global balloon flights. The data system supports global data communications utilizing the GOES satellite as well as high bit rate communications through L-band li line-of-site transmissions

Characterizing and Quantifying Time Dependent Night Sky Brightness In and Around Tucson, Arizona

NASA Astrophysics Data System (ADS)

Nydegger, Rachel

2014-01-01

As part of a Research Experience for Undergraduates (REU) program with the National Optical Astronomy Observatory (NOAO), I (with mentor Dr. Constance Walker of NOAO) characterized light pollution in and near Tucson, Arizona using eight Sky Quality Meters (SQMs). In order to analyze the data in a consistent way for comparison, we created a standard procedure for reduction and analysis using python and MATLAB. The series of python scripts remove faulty data and examine specifically anthropogenic light pollution by excluding contributions made by the sun, moon, and the Milky Way. We then use MATLAB codes to illustrate how the light pollution changes in relation to time, distance from the city, and airglow. Data are then analyzed by a recently developed sky brightness model created by Dan Duriscoe of the National Park Service. To quantify the measurements taken by SQMs, we tested the wavelength sensitivity of the devices used for the data collection. The findings from the laboratory testing have prompted innovations for the SQMs as well as given a sense of how data gathered by these devices should be treated.

A Northern Sky Survey for Point-like Sources of EeV Neutral Particles with the Telescope Array Experiment

NASA Astrophysics Data System (ADS)

Abbasi, R. U.; Abe, M.; Abu-Zayyad, T.; Allen, M.; Anderson, R.; Azuma, R.; Barcikowski, E.; Belz, J. W.; Bergman, D. R.; Blake, S. A.; Cady, R.; Chae, M. J.; Cheon, B. G.; Chiba, J.; Chikawa, M.; Cho, W. R.; Fujii, T.; Fukushima, M.; Goto, T.; Hanlon, W.; Hayashi, Y.; Hayashida, N.; Hibino, K.; Honda, K.; Ikeda, D.; Inoue, N.; Ishii, T.; Ishimori, R.; Ito, H.; Ivanov, D.; Jui, C. C. H.; Kadota, K.; Kakimoto, F.; Kalashev, O.; Kasahara, K.; Kawai, H.; Kawakami, S.; Kawana, S.; Kawata, K.; Kido, E.; Kim, H. B.; Kim, J. H.; Kim, J. H.; Kitamura, S.; Kitamura, Y.; Kuzmin, V.; Kwon, Y. J.; Lan, J.; Lim, S. I.; Lundquist, J. P.; Machida, K.; Martens, K.; Matsuda, T.; Matsuyama, T.; Matthews, J. N.; Minamino, M.; Mukai, K.; Myers, I.; Nagasawa, K.; Nagataki, S.; Nakamura, T.; Nonaka, T.; Nozato, A.; Ogio, S.; Ogura, J.; Ohnishi, M.; Ohoka, H.; Oki, K.; Okuda, T.; Ono, M.; Oshima, A.; Ozawa, S.; Park, I. H.; Pshirkov, M. S.; Rodriguez, D. C.; Rubtsov, G.; Ryu, D.; Sagawa, H.; Sakurai, N.; Sampson, A. L.; Scott, L. M.; Shah, P. D.; Shibata, F.; Shibata, T.; Shimodaira, H.; Shin, B. K.; Smith, J. D.; Sokolsky, P.; Springer, R. W.; Stokes, B. T.; Stratton, S. R.; Stroman, T. A.; Suzawa, T.; Takamura, M.; Takeda, M.; Takeishi, R.; Taketa, A.; Takita, M.; Tameda, Y.; Tanaka, H.; Tanaka, K.; Tanaka, M.; Thomas, S. B.; Thomson, G. B.; Tinyakov, P.; Tkachev, I.; Tokuno, H.; Tomida, T.; Troitsky, S.; Tsunesada, Y.; Tsutsumi, K.; Uchihori, Y.; Udo, S.; Urban, F.; Vasiloff, G.; Wong, T.; Yamane, R.; Yamaoka, H.; Yamazaki, K.; Yang, J.; Yashiro, K.; Yoneda, Y.; Yoshida, S.; Yoshii, H.; Zollinger, R.; Zundel, Z.

2015-05-01

We report on the search for steady point-like sources of neutral particles around 1018 eV between 2008 and 2013 May with the scintillator SD of the Telescope Array experiment. We found overall no significant point-like excess above 0.5 EeV in the northern sky. Subsequently, we also searched for coincidence with the Fermi bright Galactic sources. No significant coincidence was found within the statistical uncertainty. Hence, we set an upper limit on the neutron flux that corresponds to an averaged flux of 0.07 km-2 yr-1 for E\\gt 1 EeV in the northern sky at the 95% confidence level. This is the most stringent flux upper limit in a northern sky survey assuming point-like sources. The upper limit at the 95% confidence level on the neutron flux from Cygnus X-3 is also set to 0.2 km-2 yr-1 for E\\gt 0.5 EeV. This is an order of magnitude lower than previous flux measurements.

Evaluating the spatio-temporal performance of sky-imager-based solar irradiance analysis and forecasts

NASA Astrophysics Data System (ADS)

Schmidt, Thomas; Kalisch, John; Lorenz, Elke; Heinemann, Detlev

2016-03-01

Clouds are the dominant source of small-scale variability in surface solar radiation and uncertainty in its prediction. However, the increasing share of solar energy in the worldwide electric power supply increases the need for accurate solar radiation forecasts. In this work, we present results of a very short term global horizontal irradiance (GHI) forecast experiment based on hemispheric sky images. A 2-month data set with images from one sky imager and high-resolution GHI measurements from 99 pyranometers distributed over 10 km by 12 km is used for validation. We developed a multi-step model and processed GHI forecasts up to 25 min with an update interval of 15 s. A cloud type classification is used to separate the time series into different cloud scenarios. Overall, the sky-imager-based forecasts do not outperform the reference persistence forecasts. Nevertheless, we find that analysis and forecast performance depends strongly on the predominant cloud conditions. Especially convective type clouds lead to high temporal and spatial GHI variability. For cumulus cloud conditions, the analysis error is found to be lower than that introduced by a single pyranometer if it is used representatively for the whole area in distances from the camera larger than 1-2 km. Moreover, forecast skill is much higher for these conditions compared to overcast or clear sky situations causing low GHI variability, which is easier to predict by persistence. In order to generalize the cloud-induced forecast error, we identify a variability threshold indicating conditions with positive forecast skill.

PRAXIS: a low background NIR spectrograph for fibre Bragg grating OH suppression

NASA Astrophysics Data System (ADS)

Horton, Anthony; Ellis, Simon; Lawrence, Jon; Bland-Hawthorn, Joss

2012-09-01

Fibre Bragg grating (FBG) OH suppression is capable of greatly reducing the bright sky background seen by near infrared spectrographs. By filtering out the airglow emission lines at high resolution before the light enters the spectrograph this technique prevents scattering from the emission lines into interline regions, thereby reducing the background at all wavelengths. In order to take full advantage of this sky background reduction the spectrograph must have very low instrumental backgrounds so that it remains sky noise limited. Both simulations and real world experience with the prototype GNOSIS system show that existing spectrographs, designed for higher sky background levels, will be unable to fully exploit the sky background reduction. We therefore propose PRAXIS, a spectrograph optimised specifically for this purpose. The PRAXIS concept is a fibre fed, fully cryogenic, fixed format spectrograph for the J and H-bands. Dark current will be minimised by using the best of the latest generation of NIR detectors while thermal backgrounds will be reduced by the use of a cryogenic fibre slit. Optimised spectral formats and the use of high throughput volume phase holographic gratings will further enhance sensitivity. Our proposal is for a modular system, incorporating exchangeable fore-optics units, integral field units and OH suppression units, to allow PRAXIS to operate as a visitor instrument on any large telescope and enable new developments in FBG OH suppression to be incorporated as they become available. As a high performance fibre fed spectrograph PRAXIS could also serve as a testbed for other astrophotonic technologies.

Expedition Atacama - project AMOS in Chile

NASA Astrophysics Data System (ADS)

Tóth, J.; Kaniansky, S.

2016-01-01

The Slovak Video Meteor Network operates since 2009 (Tóth et al., 2011). It currently consists of four semi-automated all-sky video cameras, developed at the Astronomical Observatory in Modra, Comenius University in Bratislava, Slovakia. Two new generations of AMOS (All-sky Meteor Orbit System) cameras operate fully automatically at the Canary Islands, Tenerife and La Palma, since March 2015 (Tóth et al., 2015). As a logical step, we plan to cover the southern hemisphere from Chile. We present observational experiences in meteor astronomy from the Atacama Desert and other astronomical sites in Chile. This summary of the observations lists meteor spectra records (26) between Nov.5-13, 2015 mostly Taurid meteors, single and double station meteors as well as the first light from the permanent AMOS stations in Chile.

All-Sky Microwave Imager Data Assimilation at NASA GMAO

NASA Technical Reports Server (NTRS)

Kim, Min-Jeong; Jin, Jianjun; El Akkraoui, Amal; McCarty, Will; Todling, Ricardo; Gu, Wei; Gelaro, Ron

2017-01-01

Efforts in all-sky satellite data assimilation at the Global Modeling and Assimilation Office (GMAO) at NASA Goddard Space Flight Center have been focused on the development of GSI configurations to assimilate all-sky data from microwave imagers such as the GPM Microwave Imager (GMI) and Global Change Observation Mission-Water (GCOM-W) Advanced Microwave Scanning Radiometer 2 (AMSR-2). Electromagnetic characteristics associated with their wavelengths allow microwave imager data to be relatively transparent to atmospheric gases and thin ice clouds, and highly sensitive to precipitation. Therefore, GMAOs all-sky data assimilation efforts are primarily focused on utilizing these data in precipitating regions. The all-sky framework being tested at GMAO employs the GSI in a hybrid 4D-EnVar configuration of the Goddard Earth Observing System (GEOS) data assimilation system, which will be included in the next formal update of GEOS. This article provides an overview of the development of all-sky radiance assimilation in GEOS, including some performance metrics. In addition, various projects underway at GMAO designed to enhance the all-sky implementation will be introduced.

The Automatic Recognition of the Abnormal Sky-subtraction Spectra Based on Hadoop

NASA Astrophysics Data System (ADS)

An, An; Pan, Jingchang

2017-10-01

The skylines, superimposing on the target spectrum as a main noise, If the spectrum still contains a large number of high strength skylight residuals after sky-subtraction processing, it will not be conducive to the follow-up analysis of the target spectrum. At the same time, the LAMOST can observe a quantity of spectroscopic data in every night. We need an efficient platform to proceed the recognition of the larger numbers of abnormal sky-subtraction spectra quickly. Hadoop, as a distributed parallel data computing platform, can deal with large amounts of data effectively. In this paper, we conduct the continuum normalization firstly and then a simple and effective method will be presented to automatic recognize the abnormal sky-subtraction spectra based on Hadoop platform. Obtain through the experiment, the Hadoop platform can implement the recognition with more speed and efficiency, and the simple method can recognize the abnormal sky-subtraction spectra and find the abnormal skyline positions of different residual strength effectively, can be applied to the automatic detection of abnormal sky-subtraction of large number of spectra.

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

Liu, Adrian; Zhang, Yunfan; Parsons, Aaron R., E-mail: acliu@berkeley.edu

Intensity mapping is a promising technique for surveying the large-scale structure of our universe from z  = 0 to z  ∼ 150, using the brightness temperature field of spectral lines to directly observe previously unexplored portions of our cosmic timeline. Examples of targeted lines include the 21 cm hyperfine transition of neutral hydrogen, rotational lines of carbon monoxide, and fine-structure lines of singly ionized carbon. Recent efforts have focused on detections of the power spectrum of spatial fluctuations, but have been hindered by systematics such as foreground contamination. This has motivated the decomposition of data into Fourier modes perpendicular and parallel tomore » the line of sight, which has been shown to be a particularly powerful way to diagnose systematics. However, such a method is well-defined only in the limit of a narrow-field, flat-sky approximation. This limits the sensitivity of intensity mapping experiments, as it means that wide surveys must be separately analyzed as a patchwork of smaller fields. In this paper, we develop a framework for analyzing intensity mapping data in a spherical Fourier–Bessel basis, which incorporates curved sky effects without difficulty. We use our framework to generalize a number of techniques in intensity mapping data analysis from the flat sky to the curved sky. These include visibility-based estimators for the power spectrum, treatments of interloper lines, and the “foreground wedge” signature of spectrally smooth foregrounds.« less

Spherical Harmonic Analyses of Intensity Mapping Power Spectra

NASA Astrophysics Data System (ADS)

Liu, Adrian; Zhang, Yunfan; Parsons, Aaron R.

2016-12-01

Intensity mapping is a promising technique for surveying the large-scale structure of our universe from z = 0 to z ˜ 150, using the brightness temperature field of spectral lines to directly observe previously unexplored portions of our cosmic timeline. Examples of targeted lines include the 21 cm hyperfine transition of neutral hydrogen, rotational lines of carbon monoxide, and fine-structure lines of singly ionized carbon. Recent efforts have focused on detections of the power spectrum of spatial fluctuations, but have been hindered by systematics such as foreground contamination. This has motivated the decomposition of data into Fourier modes perpendicular and parallel to the line of sight, which has been shown to be a particularly powerful way to diagnose systematics. However, such a method is well-defined only in the limit of a narrow-field, flat-sky approximation. This limits the sensitivity of intensity mapping experiments, as it means that wide surveys must be separately analyzed as a patchwork of smaller fields. In this paper, we develop a framework for analyzing intensity mapping data in a spherical Fourier-Bessel basis, which incorporates curved sky effects without difficulty. We use our framework to generalize a number of techniques in intensity mapping data analysis from the flat sky to the curved sky. These include visibility-based estimators for the power spectrum, treatments of interloper lines, and the “foreground wedge” signature of spectrally smooth foregrounds.

A new service support tool for COSMO-SkyMed: civil user coordination service and civil request management optimization

NASA Astrophysics Data System (ADS)

Daraio, M. G.; Battagliere, M. L.; Sacco, P.; Fasano, L.; Coletta, A.

2015-10-01

COSMO-SkyMed is a dual-use program for both civilian and defense provides user community (institutional and commercial) with SAR data in several environmental applications. In the context of COSMO-SkyMed data and User management, one of the aspects carefully monitored is the user satisfaction level, it is links to satisfaction of submitted user requests. The operational experience of the first years of operational phase, and the consequent lessons learnt by the COSMO-SkyMed data and user management, have demonstrated that a lot of acquisition rejections are due to conflicts (time conflicts or system conflicts) among two or more civilian user requests, and they can be managed and solved implementing an improved coordination of users and their requests on a daily basis. With this aim a new Service Support Tool (SST) has been designed and developed to support the operators in the User Request coordination. The Tool allow to analyze conflicts among Acquisition Requests (ARs) before the National Rankization phase and to elaborate proposals for conflict resolution. In this paper the most common causes of the occurred rejections will be showed, for example as the impossibility to aggregate different orders, and the SST functionalities will be described, in particular how it works to remove or minimize the conflicts among different orders.

The New Progress of the Starry Sky Project of China

NASA Astrophysics Data System (ADS)

Wang, Xiaohua

2015-08-01

Since the 28th General Assembly of IAU, the SSPC team made new progress:1. Enhanced the function of the SSPC team-- Established the contact with IAU C50, IUCN Dark Skies Advisory Group, AWB and IDA,and undertakes the work of the IDA Beijing Chapter.-- Got supports from China’s National Astronomical Observatories, Beijing Planetarium, and Shanghai Science and Technology Museum.-- Signed cooperation agreements with Lighting Research Center, English Education Group and law Firm; formed the team force.2. Put forward a proposal to national top institutionThe SSPC submitted the first proposal about dark sky protection to the Chinese People’s Political Consultative Conference.3. Introduced the Criteria and Guideline of dark sky protectionThe SSPC team translated 8 documents of IDA, and provided a reference basis for Chinese dark sky protection.4. Actively establish dark sky places-- Plan a Dark Sky Reserve around Ali astronomical observatory (5,100m elevation) in Tibet. China’s Xinhua News Agency released the news.-- Combining with Hangcuo Lake, a National Natural Reserve and Scenic in Tibet, to plan and establish the Dark Sky Park.-- Cooperated with Shandong Longgang Tourism Group to construct the Dream Sky Theme Park in the suburbs of Jinan city.In the IYL 2015, the SSPC is getting further development:First, make dark sky protection enter National Ecological Strategy of “Beautiful China”. We call on: “Beautiful China” needs “Beautiful Night Sky” China should care the shared starry sky, and left this resource and heritage for children.Second, hold “Cosmic Light” exhibition in Shanghai Science and Technology Museum on August.Third, continue to establish Dark Sky Reserve, Park and Theme Park. We want to make these places become the bases of dark sky protection, astronomical education and ecological tourism, and develop into new cultural industry.Fourth, actively join international cooperation.Now, “Blue Sky, White Cloud and Starry Sky “have become the common pursuit of Chinese society. In order to obtain this goal, the SSPC team would like to pay more efforts.

Far Infrared All-Sky Survey

NASA Technical Reports Server (NTRS)

Richards, Paul L.

1998-01-01

Precise measurements of the angular power spectrum of the Cosmic Microwave Background (CMB) anisotropy will revolutionize cosmology. These measurements will discriminate between competing cosmological models and, if the standard inflationary scenario is correct, will determine each of the fundamental cosmological parameters with high precision. The astrophysics community has recognized this potential: the orbital experiments MAP and PLANCK, have been approved to measure CMB anisotropy. Balloon-borne experiments can realize much of this potential before these missions are launched. Additionally, properly designed balloon-borne experiments can complement MAP in frequency and angular resolution and can give the first realistic test of the instrumentation proposed for the high frequency instrument on PLANCK. The MAXIMA experiment is part of the MAXIMA/BOOMERANG collaboration which is doing balloon observations of the angular power spectrum of the Cosmic Microwave Background from l = 10 to l = 800. These experiments are designed to use the benefits of both North American and Antarctic long-duration ballooning to full advantage. We have developed several new technologies that together allow the power spectrum to be measured with unprecedented combination of angular resolution, beam throw, sensitivity, sky coverage and control of systematic effects. These technologies are the basis for the high frequency instrument for the PLANCK mission. Our measurements will strongly discriminate between models of the origin and evolution of structure in the universe and, for many models, will determine the value of the basic cosmological parameters to high precision.

The NASA SETI sky survey: Recent developments

NASA Technical Reports Server (NTRS)

Klein, M. J.; Gulkis, S.; Olsen, E. T.; Renzetti, N. A.

1989-01-01

NASA's Search for Extraterrestrial Intelligence (SETI) project utilizes two complementary search strategies: a sky survey and a targeted search. The SETI team at the Jet Propulsion Laboratory (JPL) in Pasadena, California, has primary responsibility to develop and carry out the sky survey part. Described here is progress that has been made developing the major elements of the survey including a 2-million channel wideband spectrum analyzer system that is being designed and constructed by JPL for the Deep Space Network (DSN). The system will be a multiuser instrument; it will serve as a prototype for the SETI sky survey processor. This prototype system will be used to test the signal detection and observational strategies on DSN antennas in the near future.

Repeater in the sky. [public service communications satellite program

NASA Technical Reports Server (NTRS)

Cote, C. E.; Brown, J. P.

1977-01-01

The Public Service Communications Satellite (PSCS) program is intended to develop and demonstrate a space system aimed at stimulating future commercial markets in fixed and mobile applications. The services are envisioned for rural areas, regions beyond access to terrestrial systems, or for continuous cross-country applications. The system incorporates a UHF repeater for mobile voice and data experiments; 8 MHz of spectrum is specified for serving 70 channels. This paper describes the PSCS program and discusses some demonstration experiments. A future concept based on large structure multibeam antennas is also discussed.

Radiative sky cooling: fundamental physics, materials, structures, and applications

NASA Astrophysics Data System (ADS)

Sun, Xingshu; Sun, Yubo; Zhou, Zhiguang; Alam, Muhammad Ashraful; Bermel, Peter

2017-07-01

Radiative sky cooling reduces the temperature of a system by promoting heat exchange with the sky; its key advantage is that no input energy is required. We will review the origins of radiative sky cooling from ancient times to the modern day, and illustrate how the fundamental physics of radiative cooling calls for a combination of properties that may not occur in bulk materials. A detailed comparison with recent modeling and experiments on nanophotonic structures will then illustrate the advantages of this recently emerging approach. Potential applications of these radiative cooling materials to a variety of temperature-sensitive optoelectronic devices, such as photovoltaics, thermophotovoltaics, rectennas, and infrared detectors, will then be discussed. This review will conclude by forecasting the prospects for the field as a whole in both terrestrial and space-based systems.

Imaging spectropolarimetry of cloudy skies

NASA Astrophysics Data System (ADS)

Pust, Nathan; Shaw, Joseph A.

2006-05-01

The polarization state of atmospheric radiance varies with cloudiness and cloud type. We have developed a dual-field-of-view imaging spectro-polarimeter for measuring atmospheric polarization in five spectral bands from 450 to 700 nm. This instrument improves the acquisition time of past full-sky digital camera designs to 400 ms using liquid crystal variable retarders (LCVRs). The system can be used to measure polarization with either fisheye or telephoto optics, allowing studies of all-sky and target polarization. We present and describe measurements of sky polarization with clear and variably cloudy sky conditions. In clear skies, we observe a slight upward trend of the degree of polarization with wavelength, in agreement with previous observations. Presence of clouds generally reduces both cloudy sky and surrounding clear sky degree of polarization. The polarization measured from a cloud often reflects only the Rayleigh scattering between the instrument and the cloud, but some of our recent data shows partially polarized cloud scattering.

Sky Subtraction with Fiber-Fed Spectrograph

NASA Astrophysics Data System (ADS)

Rodrigues, Myriam

2017-09-01

"Historically, fiber-fed spectrographs had been deemed inadequate for the observation of faint targets, mainly because of the difficulty to achieve high accuracy on the sky subtraction. The impossibility to sample the sky in the immediate vicinity of the target in fiber instruments has led to a commonly held view that a multi-object fibre spectrograph cannot achieve an accurate sky subtraction under 1% contrary to their slit counterpart. The next generation of multi-objects spectrograph at the VLT (MOONS) and the planed MOS for the E-ELT (MOSAIC) are fiber-fed instruments, and are aimed to observed targets fainter than the sky continuum level. In this talk, I will present the state-of-art on sky subtraction strategies and data reduction algorithm specifically developed for fiber-fed spectrographs. I will also present the main results of an observational campaign to better characterise the sky spatial and temporal variations ( in particular the continuum and faint sky lines)."

CFHT's SkyProbe: a real-time sky-transparency monitor

NASA Astrophysics Data System (ADS)

Cuillandre, Jean-Charles; Magnier, Eugene A.; Isani, Sidik; Sabin, Daniel; Knight, Wiley; Kras, Simon; Lai, Kamson

2002-12-01

We have developed a system at the Canada-France-Hawaii Telescope (CFHT), SkyProbe, which allows for the direct measurement of the true attenuation by clouds once per minute, within a percent, directly on the field pointed by the telescope. It has been possible to make this system relatively inexpensively due to the low-cost CCD cameras from the amateur market. A crucial addition to this hardware is the quite recent availability of a full-sky photometry catalog at the appropriate depth: the Tycho catalog, from the Hipparcos mission. The central element is the automatic data analysis pipeline developed at CFHT, Elixir, for the improved operation of the CFHT wide-field imagers, CFH12K and MegaCam. SkyProbe"s FITS images are processed in real-time and the pipeline output (a zero point attenuation) provides the current sky transmission to the observers and helps immediate decision making. These measurements are also attached to the archived data, adding a key criteria for future use by other astronomers.

PePSS - A portable sky scanner for measuring extremely low night-sky brightness

NASA Astrophysics Data System (ADS)

Kocifaj, Miroslav; Kómar, Ladislav; Kundracik, František

2018-05-01

A new portable sky scanner designed for low-light-level detection at night is developed and employed in night sky brightness measurements in a rural region. The fast readout, adjustable sensitivity and linear response guaranteed in 5-6 orders of magnitude makes the device well suited for narrow-band photometry in both dark areas and bright urban and suburban environments. Quasi-monochromatic night-sky brightness data are advantageous in the accurate characterization of spectral power distribution of scattered and emitted light and, also allows for the possibility to retrieve light output patterns from whole-city light sources. The sky scanner can operate in both night and day regimes, taking advantage of the complementarity of both radiance data types. Due to its inherent very high sensitivity the photomultiplier tube could be used in night sky radiometry, while the spectrometer-equipped system component capable of detecting elevated intensities is used in daylight monitoring. Daylight is a source of information on atmospheric optical properties that in turn are necessary in processing night sky radiances. We believe that the sky scanner has the potential to revolutionize night-sky monitoring systems.

Cosmic bandits: Exploration versus exploitation in CMB B-mode experiments

NASA Astrophysics Data System (ADS)

Kovetz, Ely D.; Kamionkowski, Marc

2016-02-01

A preferred method to detect the curl-component, or B-mode, signature of inflationary gravitational waves (IGWs) in the cosmic microwave background (CMB) polarization, in the absence of foregrounds and lensing, is a prolonged integration over a single patch of sky of a few square degrees. In practice, however, foregrounds abound and the sensitivity to B modes can be improved considerably by finding the region of sky cleanest of foregrounds. The best strategy to detect B modes thus involves a tradeoff between exploration (to find lower-foreground patches) and exploitation (through prolonged integration). This problem is akin to the multi-armed bandit (MAB) problem in probability theory, wherein a gambler faces a series of slot machines with unknown winning odds and must develop a strategy to maximize his/her winnings with some finite number of pulls. While the optimal MAB strategy remains to be determined, a number of algorithms have been developed in an effort to maximize the winnings. Here, based on this resemblance, we tackle the search for IGW B modes with single frequency experiments in the presence of spatially varying foregrounds by developing adaptive survey strategies to optimize the sensitivity to IGW B modes. We demonstrate, using realistic foreground models and taking lensing-induced B modes into account, that adaptive experiments can substantially improve the upper bound on the tensor-to-scalar ratio (by factors of 2 and 3 in single frequency experiments, and possibly even more). Similar techniques can be applied to other surveys, including 21-cm measurements of signatures of the epoch of reionization, searches for a stochastic primordial gravitational wave background, deep-field imaging by the James Webb Space Telescope or various radio interferometers, and transient follow-up searches.

A computer program to determine the possible daily release window for sky target experiments

NASA Technical Reports Server (NTRS)

Michaud, N. H.

1973-01-01

A computer program is presented which is designed to determine the daily release window for sky target experiments. Factors considered in the program include: (1) target illumination by the sun at release time and during the tracking period; (2) look angle elevation above local horizon from each tracking station to the target; (3) solar depression angle from the local horizon of each tracking station during the experimental period after target release; (4) lunar depression angle from the local horizon of each tracking station during the experimental period after target release; and (5) total sky background brightness as seen from each tracking station while viewing the target. Program output is produced in both graphic and data form. Output data can be plotted for a single calendar month or year. The numerical values used to generate the plots are furnished to permit a more detailed review of the computed daily release windows.

PROBING THE DARK AGES AT z ∼ 20: THE SCI-HI 21 cm ALL-SKY SPECTRUM EXPERIMENT

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

Voytek, Tabitha C.; Natarajan, Aravind; Peterson, Jeffrey B.

2014-02-10

We present first results from the SCI-HI experiment, which we used to measure the all-sky-averaged 21 cm brightness temperature in the redshift range 14.8 < z < 22.7. The instrument consists of a single broadband sub-wavelength size antenna and a sampling system for real-time data processing and recording. Preliminary observations were completed in 2013 June at Isla Guadalupe, a Mexican biosphere reserve located in the Pacific Ocean. The data was cleaned to excise channels contaminated by radio frequency interference, and the system response was calibrated by comparing the measured brightness temperature to the Global Sky Model of the Galaxy and bymore » independent measurement of Johnson noise from a calibration terminator. We present our results, discuss the cosmological implications, and describe plans for future work.« less

Air Shower Detection and Sky Survey with the ARGO-YBJ Experiment

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

Bleve, C.; Sezione INFN di Lecce, via per Arnesano, 73100 Lecce

2006-02-08

The ARGO-YBJ detector, located in Tibet at 4300 m a.s.l., is a full-coverage Extensive Air-Shower Array consisting of a single layer of Resistive Plate Chambers. The main scientific goals of the experiment are the study of cosmic rays and the detection of astrophysical {gamma} radiation at few hundreds GeV energy threshold. About 30% of the foreseen active area is in stable data taking since December 2004. The analysis of first data shows that the detector is working properly and that ARGO-YBJ has the capability to image extensive air showers with unprecedented granularity and to monitor continuously the Northern Sky searchingmore » for steady and transient sources of {gamma}-rays. In this paper we report some results about the air shower detection and the first sky map covering the declination band -20 deg. < {delta} <80 deg.« less

Indications of Intermediate-scale Anisotropy of Cosmic Rays with Energy Greater Than 57 EeV in the Northern Sky Measured with the Surface Detector of the Telescope Array Experiment

NASA Astrophysics Data System (ADS)

Abbasi, R. U.; Abe, M.; Abu-Zayyad, T.; Allen, M.; Anderson, R.; Azuma, R.; Barcikowski, E.; Belz, J. W.; Bergman, D. R.; Blake, S. A.; Cady, R.; Chae, M. J.; Cheon, B. G.; Chiba, J.; Chikawa, M.; Cho, W. R.; Fujii, T.; Fukushima, M.; Goto, T.; Hanlon, W.; Hayashi, Y.; Hayashida, N.; Hibino, K.; Honda, K.; Ikeda, D.; Inoue, N.; Ishii, T.; Ishimori, R.; Ito, H.; Ivanov, D.; Jui, C. C. H.; Kadota, K.; Kakimoto, F.; Kalashev, O.; Kasahara, K.; Kawai, H.; Kawakami, S.; Kawana, S.; Kawata, K.; Kido, E.; Kim, H. B.; Kim, J. H.; Kim, J. H.; Kitamura, S.; Kitamura, Y.; Kuzmin, V.; Kwon, Y. J.; Lan, J.; Lim, S. I.; Lundquist, J. P.; Machida, K.; Martens, K.; Matsuda, T.; Matsuyama, T.; Matthews, J. N.; Minamino, M.; Mukai, K.; Myers, I.; Nagasawa, K.; Nagataki, S.; Nakamura, T.; Nonaka, T.; Nozato, A.; Ogio, S.; Ogura, J.; Ohnishi, M.; Ohoka, H.; Oki, K.; Okuda, T.; Ono, M.; Oshima, A.; Ozawa, S.; Park, I. H.; Pshirkov, M. S.; Rodriguez, D. C.; Rubtsov, G.; Ryu, D.; Sagawa, H.; Sakurai, N.; Sampson, A. L.; Scott, L. M.; Shah, P. D.; Shibata, F.; Shibata, T.; Shimodaira, H.; Shin, B. K.; Smith, J. D.; Sokolsky, P.; Springer, R. W.; Stokes, B. T.; Stratton, S. R.; Stroman, T. A.; Suzawa, T.; Takamura, M.; Takeda, M.; Takeishi, R.; Taketa, A.; Takita, M.; Tameda, Y.; Tanaka, H.; Tanaka, K.; Tanaka, M.; Thomas, S. B.; Thomson, G. B.; Tinyakov, P.; Tkachev, I.; Tokuno, H.; Tomida, T.; Troitsky, S.; Tsunesada, Y.; Tsutsumi, K.; Uchihori, Y.; Udo, S.; Urban, F.; Vasiloff, G.; Wong, T.; Yamane, R.; Yamaoka, H.; Yamazaki, K.; Yang, J.; Yashiro, K.; Yoneda, Y.; Yoshida, S.; Yoshii, H.; Zollinger, R.; Zundel, Z.

2014-08-01

We have searched for intermediate-scale anisotropy in the arrival directions of ultrahigh-energy cosmic rays with energies above 57 EeV in the northern sky using data collected over a 5 yr period by the surface detector of the Telescope Array experiment. We report on a cluster of events that we call the hotspot, found by oversampling using 20° radius circles. The hotspot has a Li-Ma statistical significance of 5.1σ, and is centered at R.A. = 146.°7, decl. = 43.°2. The position of the hotspot is about 19° off of the supergalactic plane. The probability of a cluster of events of 5.1σ significance, appearing by chance in an isotropic cosmic-ray sky, is estimated to be 3.7 × 10-4 (3.4σ).

Globe at Night: From IYA2009 to the International Year of Light 2015 and Beyond

NASA Astrophysics Data System (ADS)

Walker, Constance Elaine; Pompea, Stephen M.; Sparks, Robert T.

2015-08-01

Citizen-science is a rewardingly inclusive way to bring awareness to the public on important issues like the disappearing starry night sky, its cause and solutions. Citizen-science can also provide meaningful, hands-on “science process” experiences for students. One program that does both is Globe at Night (www.globeatnight.org), an international campaign to raise public awareness of the impact of light pollution by having people measure night-sky brightness and submit observations via a “web app” on any smart device or computer. Additionally, 2 native mobile apps - Loss of the Night for iPhone & Android, and Dark Sky Meter for iPhone - support Globe at Night.Since 2006, more than 125,000 vetted measurements from 115 countries have been reported. For 2015 the campaign is offered as a 10-day observation window each month when the Moon is not up. To facilitate Globe at Night as an international project, the web app and other materials are in many languages. (See www.globeatnight.org/downloads.)Students and the general public can use the data to monitor levels of light pollution around the world, as well as understand light pollution’s effects on energy consumption, plants, wildlife, human health and our ability to enjoy a starry night sky. Projects have compared Globe at Night data with ground-truthing using meters for energy audits as well as with data on birds and bats, population density, satellite data and trends over time. Globe at Night tackles grand challenges and everyday problems. It provides resources for formal and informal educators to engage learners of all ages. It has 9 years of experience in best practices for data management, design, collection, visualization, interpretation, etc. It has externally evaluated its program, workshops, lesson plans and accompanying kit to explore reasons for participation, skills developed, impact of experiences and perceived outcomes. Three recent papers (Birriel et al. 2014; Kyba et al. 2013; 2015) verify the database’s validity for use in scientific research.Globe at Night played a central role in IYA2009 and is now a citizen science campaign for the International Year of Light 2015

Spatial Model of Sky Brightness Magnitude in Langkawi Island, Malaysia

NASA Astrophysics Data System (ADS)

Redzuan Tahar, Mohammad; Kamarudin, Farahana; Umar, Roslan; Khairul Amri Kamarudin, Mohd; Sabri, Nor Hazmin; Ahmad, Karzaman; Rahim, Sobri Abdul; Sharul Aikal Baharim, Mohd

2017-03-01

Sky brightness is an essential topic in the field of astronomy, especially for optical astronomical observations that need very clear and dark sky conditions. This study presents the spatial model of sky brightness magnitude in Langkawi Island, Malaysia. Two types of Sky Quality Meter (SQM) manufactured by Unihedron are used to measure the sky brightness on a moonless night (or when the Moon is below the horizon), when the sky is cloudless and the locations are at least 100 m from the nearest light source. The selected locations are marked by their GPS coordinates. The sky brightness data obtained in this study were interpolated and analyzed using a Geographic Information System (GIS), thus producing a spatial model of sky brightness that clearly shows the dark and bright sky areas in Langkawi Island. Surprisingly, our results show the existence of a few dark sites nearby areas of high human activity. The sky brightness of 21.45 mag arcsec{}-2 in the Johnson-Cousins V-band, as the average of sky brightness equivalent to 2.8 × {10}-4{cd} {{{m}}}-2 over the entire island, is an indication that the island is, overall, still relatively dark. However, the amount of development taking place might reduce the number in the near future as the island is famous as a holiday destination.

National education program for energy efficient illumination engineering

NASA Astrophysics Data System (ADS)

Walker, Constance E.; Pompea, Stephen M.

2011-05-01

About one-third of outdoor lighting escapes unused into the sky, wasting energy and causing sky glow. Because of excessive sky glow around astronomical facilities, the National Optical Astronomy Observatory has a strong motivation to lead light pollution education efforts. While our original motivation of preserving the dark skies near observatories is still important, energy conservation is a critical problem that needs to be addressed nationwide. To address this problem we have created an extensive educational program on understanding and measuring light pollution. A set of four learning experiences introduces school students at all grade levels to basic energy-responsive illumination engineering design principles that can minimize light pollution. We created and utilize the GLOBE at Night citizen science light pollution assessment campaign as a cornerstone activity. We also utilize educational activities on light shielding that are introduced through a teaching kit. These two components provide vocabulary, concepts, and visual illustrations of the causes of light pollution. The third, more advanced component is the school outdoor lighting audit, which has students perform an audit and produce a revised master plan for compliant lighting. These learning experiences provide an integrated learning unit that is highly adaptable for U.S. and international education efforts in this area.

PAPER: The Precision Array to Probe the Epoch of Reionization

NASA Astrophysics Data System (ADS)

Backer, Donald C.; PAPER Team

2009-01-01

PAPER is being developed for an experiment series whose long term goal is detection of the power spectrum of faint, redshifted-21cm signals from hydrogen heated by the first stars during the epoch of reionization. Our instrumentation goals include: of dipole elements that are optimized for operation from 100-200 MHz with a clean beam response; amplifiers and receivers with good impedance match and smooth gain response over a wide bandpass; FPGA-based correlator (Parsons et al. 2008) capable of producing full stokes products for the non-tracking array; and a calibration and imaging package (AIPY) tailored to the unique problem of ultrawide field imaging. PAPER is being built and tested in stages at the NRAO Green Bank, WV site with deployment of the full instrument in Western Australia. Results from a 16-station deployment in September 2008 in Green Bank (PGB-16) are presented including: phase and amplitude calibration; RFI mitigation; full northern sky maps; and wide-field snapshot imaging. Our previous PGB-8 (8 dipole) results already reach down below 100 mJy per synthesized beam (4 K) in cold parts of the sky. We are developing new techniques to improve system stability: ambient temperature to track active balun gain variations and ORBCOM satellite monitoring to assess beam pattern and ionospheric phase gradients. In 2009 we will deploy a 64-antenna PAPER at the Murchison Radio Observatory in the outback of Western Australia (PWA-64). Our initial PWA-4 experiment in 2007 July with 4 dipoles showed the dramatic improvement in data quality owing to the ultra radio quiet site. A multi-month integration will be done during 2009 Sep-Dec when the coldest synchrotron sky is overhead at night, when the sun is down and the ionospheric column density is minimal. The depth of this integration toward our detection goal will be highly dependent on calibration and imaging algorithm development.

Spectrometers for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) Upgrade to Full Sun-Sky-Cloud-Trace Gas Spectrometry Capability for Airborne Science

NASA Astrophysics Data System (ADS)

Dunagan, S. E.; Flynn, C. J.; Johnson, R. R.; Kacenelenbogen, M. S.; Knobelspiesse, K. D.; LeBlanc, S. E.; Livingston, J. M.; Redemann, J.; Russell, P. B.; Schmid, B.; Segal-Rosenhaimer, M.; Shinozuka, Y.

2014-12-01

The Spectrometers for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) instrument has been developed at NASA Ames in collaboration with Pacific Northwest National Laboratory (PNNL) and NASA Goddard, supported substantially since 2009 by NASA's Radiation Science Program and Earth Science Technology Office. It combines grating spectrometers with fiber optic links to a tracking, scanning head to enable sun tracking, sky scanning, and zenith viewing. 4STAR builds on the long and productive heritage of the NASA Ames Airborne Tracking Sunphotometers (AATS-6 and -14), which have yielded more than 100 peer-reviewed publications and extensive archived data sets in many NASA Airborne Science campaigns from 1986 to the present. The baseline 4STAR instrument has provided extensive data supporting the TCAP (Two Column Aerosol Project, July 2012 & Feb. 2013), SEAC4RS (Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys, 2013), and ARISE (Arctic Radiation - IceBridge Sea and Ice Experiment, 2014), field campaigns.This poster presents plans and progress for an upgrade to the 4STAR instrument to achieve full science capability, including (1) direct-beam sun tracking measurements to derive aerosol optical depth spectra, (2) sky radiance measurements to retrieve aerosol absorption and type (via complex refractive index and mode-resolved size distribution), (3) cloud properties via zenith radiance, and (4) trace gas spectrometry. Technical progress in context with the governing physics is reported on several upgrades directed at improved light collection and usage, particularly as related to spectrally and radiometrically stable propagation through the collection light path. In addition, improvements to field calibration and verification, and flight operability and reliability are addressed.

A two-step framework for reconstructing remotely sensed land surface temperatures contaminated by cloud

NASA Astrophysics Data System (ADS)

Zeng, Chao; Long, Di; Shen, Huanfeng; Wu, Penghai; Cui, Yaokui; Hong, Yang

2018-07-01

Land surface temperature (LST) is one of the most important parameters in land surface processes. Although satellite-derived LST can provide valuable information, the value is often limited by cloud contamination. In this paper, a two-step satellite-derived LST reconstruction framework is proposed. First, a multi-temporal reconstruction algorithm is introduced to recover invalid LST values using multiple LST images with reference to corresponding remotely sensed vegetation index. Then, all cloud-contaminated areas are temporally filled with hypothetical clear-sky LST values. Second, a surface energy balance equation-based procedure is used to correct for the filled values. With shortwave irradiation data, the clear-sky LST is corrected to the real LST under cloudy conditions. A series of experiments have been performed to demonstrate the effectiveness of the developed approach. Quantitative evaluation results indicate that the proposed method can recover LST in different surface types with mean average errors in 3-6 K. The experiments also indicate that the time interval between the multi-temporal LST images has a greater impact on the results than the size of the contaminated area.

Testing avian compass calibration: comparative experiments with diurnal and nocturnal passerine migrants in South Sweden

PubMed Central

Åkesson, Susanne; Odin, Catharina; Hegedüs, Ramón; Ilieva, Mihaela; Sjöholm, Christoffer; Farkas, Alexandra; Horváth, Gábor

2015-01-01

ABSTRACT Cue-conflict experiments were performed to study the compass calibration of one predominantly diurnal migrant, the dunnock (Prunella modularis), and two species of nocturnal passerine migrants, the sedge warbler (Acrocephalus schoenobaenus), and the European robin (Erithacus rubecula) during autumn migration in South Sweden. The birds' orientation was recorded in circular cages under natural clear and simulated overcast skies in the local geomagnetic field, and thereafter the birds were exposed to a cue-conflict situation where the horizontal component of the magnetic field (mN) was shifted +90° or −90° at two occasions, one session starting shortly after sunrise and the other ca. 90 min before sunset and lasting for 60 min. The patterns of the degree and angle of skylight polarization were measured by full-sky imaging polarimetry during the cue-conflict exposures and orientation tests. All species showed orientation both under clear and overcast skies that correlated with the expected migratory orientation towards southwest to south. For the European robin the orientation under clear skies was significantly different from that recorded under overcast skies, showing a tendency that the orientation under clear skies was influenced by the position of the Sun at sunset resulting in more westerly orientation. This sun attraction was not observed for the sedge warbler and the dunnock, both orientating south. All species showed similar orientation after the cue-conflict as compared to the preferred orientation recorded before the cue-conflict, with the clearest results in the European robin and thus, the results did not support recalibration of the celestial nor the magnetic compasses as a result of the cue-conflict exposure. PMID:25505150

Comparison of the observed and calculated clear sky greenhouse effect - Implications for climate studies

NASA Technical Reports Server (NTRS)

Kiehl, J. T.; Briegleb, B. P.

1992-01-01

The clear sky greenhouse effect is defined in terms of the outgoing longwave clear sky flux at the top of the atmosphere. Recently, interest in the magnitude of the clear sky greenhouse effect has increased due to the archiving of the clear sky flux quantity through the Earth Radiation Budget Experiment (ERBE). The present study investigates to what degree of accuracy this flux can be analyzed by using independent atmospheric and surface data in conjunction with a detailed longwave radiation model. The conclusion from this comparison is that for most regions over oceans the analyzed fluxes agree to within the accuracy of the ERBE-retrieved fluxes (+/- 5 W/sq m). However, in regions where deep convective activity occurs, the ERBE fluxes are significantly higher (10-15 W/sq m) than the calculated fluxes. This bias can arise from either cloud contamination problems or variability in water vapor amount. It is argued that the use of analyzed fluxes may provide a more consistent clear sky flux data set for general circulation modeling validation. Climate implications from the analyzed fluxes are explored. Finally, results for obtaining longwave surface fluxes over the oceans are presented.

Mining the SDSS SkyServer SQL queries log

NASA Astrophysics Data System (ADS)

Hirota, Vitor M.; Santos, Rafael; Raddick, Jordan; Thakar, Ani

2016-05-01

SkyServer, the Internet portal for the Sloan Digital Sky Survey (SDSS) astronomic catalog, provides a set of tools that allows data access for astronomers and scientific education. One of SkyServer data access interfaces allows users to enter ad-hoc SQL statements to query the catalog. SkyServer also presents some template queries that can be used as basis for more complex queries. This interface has logged over 330 million queries submitted since 2001. It is expected that analysis of this data can be used to investigate usage patterns, identify potential new classes of queries, find similar queries, etc. and to shed some light on how users interact with the Sloan Digital Sky Survey data and how scientists have adopted the new paradigm of e-Science, which could in turn lead to enhancements on the user interfaces and experience in general. In this paper we review some approaches to SQL query mining, apply the traditional techniques used in the literature and present lessons learned, namely, that the general text mining approach for feature extraction and clustering does not seem to be adequate for this type of data, and, most importantly, we find that this type of analysis can result in very different queries being clustered together.

Integration of polarization and chromatic cues in the insect sky compass.

PubMed

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

2014-06-01

Animals relying on a celestial compass for spatial orientation may use the position of the sun, the chromatic or intensity gradient of the sky, the polarization pattern of the sky, or a combination of these cues as compass signals. Behavioral experiments in bees and ants, indeed, showed that direct sunlight and sky polarization play a role in sky compass orientation, but the relative importance of these cues are species-specific. Intracellular recordings from polarization-sensitive interneurons in the desert locust and monarch butterfly suggest that inputs from different eye regions, including polarized-light input through the dorsal rim area of the eye and chromatic/intensity gradient input from the main eye, are combined at the level of the medulla to create a robust compass signal. Conflicting input from the polarization and chromatic/intensity channel, resulting from eccentric receptive fields, is eliminated at the level of the anterior optic tubercle and central complex through internal compensation for changing solar elevations, which requires input from a circadian clock. Across several species, the central complex likely serves as an internal sky compass, combining E-vector information with other celestial cues. Descending neurons, likewise, respond both to zenithal polarization and to unpolarized cues in an azimuth-dependent way.

Radiative sky cooling: fundamental physics, materials, structures, and applications

DOE PAGES

Sun, Xingshu; Sun, Yubo; Zhou, Zhiguang; ...

2017-07-29

Radiative sky cooling reduces the temperature of a system by promoting heat exchange with the sky; its key advantage is that no input energy is required. We will review the origins of radiative sky cooling from ancient times to the modern day, and illustrate how the fundamental physics of radiative cooling calls for a combination of properties that may not occur in bulk materials. A detailed comparison with recent modeling and experiments on nanophotonic structures will then illustrate the advantages of this recently emerging approach. Potential applications of these radiative cooling materials to a variety of temperature-sensitive optoelectronic devices, suchmore » as photovoltaics, thermophotovoltaics, rectennas, and infrared detectors, will then be discussed. This review will conclude by forecasting the prospects for the field as a whole in both terrestrial and space-based systems.« less

Radiative sky cooling: fundamental physics, materials, structures, and applications

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

Sun, Xingshu; Sun, Yubo; Zhou, Zhiguang

Radiative sky cooling reduces the temperature of a system by promoting heat exchange with the sky; its key advantage is that no input energy is required. We will review the origins of radiative sky cooling from ancient times to the modern day, and illustrate how the fundamental physics of radiative cooling calls for a combination of properties that may not occur in bulk materials. A detailed comparison with recent modeling and experiments on nanophotonic structures will then illustrate the advantages of this recently emerging approach. Potential applications of these radiative cooling materials to a variety of temperature-sensitive optoelectronic devices, suchmore » as photovoltaics, thermophotovoltaics, rectennas, and infrared detectors, will then be discussed. This review will conclude by forecasting the prospects for the field as a whole in both terrestrial and space-based systems.« less

Impacts of field of view configuration of Cross-track Infrared Sounder on clear-sky observations.

PubMed

Wang, Likun; Chen, Yong; Han, Yong

2016-09-01

Hyperspectral infrared radiance measurements from satellite sensors contain valuable information on atmospheric temperature and humidity profiles and greenhouse gases, and therefore are directly assimilated into numerical weather prediction (NWP) models as inputs for weather forecasting. However, data assimilations in current operational NWP models still mainly rely on cloud-free observations due to the challenge of simulating cloud-contaminated radiances when using hyperspectral radiances. The limited spatial coverage of the 3×3 field of views (FOVs) in one field of regard (FOR) (i.e., spatial gap among FOVs) as well as relatively large footprint size (14 km) in current Cross-track Infrared Sounder (CrIS) instruments limits the amount of clear-sky observations. This study explores the potential impacts of future CrIS FOV configuration (including FOV size and spatial coverage) on the amount of clear-sky observations by simulation experiments. The radiance measurements and cloud mask products (VCM) from the Visible Infrared Imager Radiometer Suite (VIIRS) are used to simulate CrIS clear-sky observation under different FOV configurations. The results indicate that, given the same FOV coverage (e.g., 3×3), the percentage of clear-sky FOVs and the percentage of clear-sky FORs (that contain at least one clear-sky FOV) both increase as the FOV size decreases. In particular, if the CrIS FOV size were reduced from 14 km to 7 km, the percentage of clear-sky FOVs increases from 9.02% to 13.51% and the percentage of clear-sky FORs increases from 18.24% to 27.51%. Given the same FOV size but with increasing FOV coverage in each FOR, the clear-sky FOV observations increases proportionally with the increasing sampling FOVs. Both reducing FOV size and increasing FOV coverage can result in more clear-sky FORs, which benefit data utilization of NWP data assimilation.

A high performance cost-effective digital complex correlator for an X-band polarimetry survey.

PubMed

Bergano, Miguel; Rocha, Armando; Cupido, Luís; Barbosa, Domingos; Villela, Thyrso; Boas, José Vilas; Rocha, Graça; Smoot, George F

2016-01-01

The detailed knowledge of the Milky Way radio emission is important to characterize galactic foregrounds masking extragalactic and cosmological signals. The update of the global sky models describing radio emissions over a very large spectral band requires high sensitivity experiments capable of observing large sky areas with long integration times. Here, we present the design of a new 10 GHz (X-band) polarimeter digital back-end to map the polarization components of the galactic synchrotron radiation field of the Northern Hemisphere sky. The design follows the digital processing trends in radio astronomy and implements a large bandwidth (1 GHz) digital complex cross-correlator to extract the Stokes parameters of the incoming synchrotron radiation field. The hardware constraints cover the implemented VLSI hardware description language code and the preliminary results. The implementation is based on the simultaneous digitized acquisition of the Cartesian components of the two linear receiver polarization channels. The design strategy involves a double data rate acquisition of the ADC interleaved parallel bus, and field programmable gate array device programming at the register transfer mode. The digital core of the back-end is capable of processing 32 Gbps and is built around an Altera field programmable gate array clocked at 250 MHz, 1 GSps analog to digital converters and a clock generator. The control of the field programmable gate array internal signal delays and a convenient use of its phase locked loops provide the timing requirements to achieve the target bandwidths and sensitivity. This solution is convenient for radio astronomy experiments requiring large bandwidth, high functionality, high volume availability and low cost. Of particular interest, this correlator was developed for the Galactic Emission Mapping project and is suitable for large sky area polarization continuum surveys. The solutions may also be adapted to be used at signal processing subsystem levels for large projects like the square kilometer array testbeds.

Basic Color Terms (BCTs) and Categories (BCCs) in Three Dialects of the Spanish Language: Interaction Between Cultural and Universal Factors.

PubMed

Lillo, Julio; González-Perilli, Fernando; Prado-León, Lilia; Melnikova, Anna; Álvaro, Leticia; Collado, José A; Moreira, Humberto

2018-01-01

Two experiments were performed to identify and compare the Basic Color Terms (BCTs) and the Basic Color Categories (BCCs) included in three dialects (Castilian, Mexican, and Uruguayan) of the Spanish language. Monolexemic Elicited lists were used in the first experiment to identify the BCTs of each dialect. Eleven BCTs appeared for the Spanish and the Mexican, and twelve did so for the Uruguayan. The six primary BCTs ( rojo "red," verde "green," amarillo "yellow," azul "blue," negro "black," and blanco "white") appeared in the three dialects. This occurred for only three derived BCTs ( gris "gray," naranja "orange," and rosa "pink") but not for the other five derived BCTs ( celeste "sky blue," marrón "brown," café "brown," morado "purple," and violeta "purple"). Color transitions were used in the second experiment for two different tasks. Extremes naming task was used to determine the relation between two different dialects' BCTs: equality, equivalence or difference. The results provided the first evidence for marrón "brown" and café "brown" being equivalent terms for the same BCC (brown in English) as is the case of morado "purple" and violeta "purple." Uruguayan celeste "sky blue" had no equivalent BCT in the other two dialects. Boundary delimitation task required the selection of the color in the boundary between two categories. The task was used to reasonably estimate the volume occupied by each BCC in the color space considering its chromatic area and lightness range. Excluding sky blue ( celeste "sky blue") and blue ( azul "blue"), the other BCCs color volumes were similar across the three dialects. Uruguayan sky blue and blue volumes conjointly occupied the portion of the color space corresponding to the Castilian and Mexican blue BCC. The fact that the BCT celeste "sky blue" only appeared in Uruguayan very probably derived from specific cultural factors (the use of the color in the flags and the arrival of an important number of Italian immigrants). Nevertheless, these cultural factors seem to nurture from a perceptive structuring of the color space, which nature is universal, as the boundaries of this category can be delimited from the responses of Spanish and Mexican participants.

Network based sky Brightness Monitor

NASA Astrophysics Data System (ADS)

McKenna, Dan; Pulvermacher, R.; Davis, D. R.

2009-01-01

We have developed and are currently testing an autonomous 2 channel photometer designed to measure the night sky brightness in the visual wavelengths over a multi-year campaign. The photometer uses a robust silicon sensor filtered with Hoya CM500 glass. The Sky brightness is measured every minute at two elevation angles typically zenith and 20 degrees to monitor brightness and transparency. The Sky Brightness monitor consists of two units, the remote photometer and a network interface. Currently these devices use 2.4 Ghz transceivers with a free space range of 100 meters. The remote unit is battery powered with day time recharging using a solar panel. Data received by the network interface transmits data via standard POP Email protocol. A second version is under development for radio sensitive areas using an optical fiber for data transmission. We will present the current comparison with the National Park Service sky monitoring camera. We will also discuss the calibration methods used for standardization and temperature compensation. This system is expected to be deployed in the next year and be operated by the International Dark Sky Association SKYMONITOR project.

Promoting Dark Sky Protection in Chile: the Gabriel Mistral IDA Dark Sky Sanctuary and Other AURA Initiatives

NASA Astrophysics Data System (ADS)

Smith, R. Chris; Smith, Malcolm; Pompea, Stephen; Sanhueza, Pedro; AURA-Chile EPO Team

2018-01-01

For over 20 years, AURA has been leading efforts promoting the protection of dark skies in northern Chile. Efforts began in the early 1990s at AURA's Cerro Tololo Inter-American Observatory (CTIO), working in collaboration with other international observatories in Chile including Las Campanas Observatory (LCO) and the European Southern Observatory (ESO). CTIO also partnered with local communities, for example supporting Vicuña's effort to establish the first municipal observatory in Chile. Today we have developed a multifaceted effort of dark sky protection, including proactive government relations at national and local levels, a strong educational and public outreach program, and a program of highlighting international recognition of the dark skies through the IDA Dark Sky Places program. Work on international recognition has included the declaration of the Gabriel Mistral IDA Dark Sky Sanctuary, the first such IDA sanctuary in the world.

Measuring high-resolution sky luminance distributions with a CCD camera.

PubMed

Tohsing, Korntip; Schrempf, Michael; Riechelmann, Stefan; Schilke, Holger; Seckmeyer, Gunther

2013-03-10

We describe how sky luminance can be derived from a newly developed hemispherical sky imager (HSI) system. The system contains a commercial compact charge coupled device (CCD) camera equipped with a fish-eye lens. The projection of the camera system has been found to be nearly equidistant. The luminance from the high dynamic range images has been calculated and then validated with luminance data measured by a CCD array spectroradiometer. The deviation between both datasets is less than 10% for cloudless and completely overcast skies, and differs by no more than 20% for all sky conditions. The global illuminance derived from the HSI pictures deviates by less than 5% and 20% under cloudless and cloudy skies for solar zenith angles less than 80°, respectively. This system is therefore capable of measuring sky luminance with the high spatial and temporal resolution of more than a million pixels and every 20 s respectively.

VizieR Online Data Catalog: Northern Sky Variability Survey (Wozniak+, 2004)

NASA Astrophysics Data System (ADS)

Wozniak, P. R.; Vestrand, W. T.; Akerlof, C. W.; Balsano, R.; Bloch, J.; Casperson, D.; Fletcher, S.; Gisler, G.; Kehoe, R.; Kinemuchi, K.; Lee, B. C.; Marshall, S.; McGowan, K. E.; McKay, T. A.; Rykoff, E. S.; Smith, D. A.; Szymanski, J.; Wren, J.

2004-11-01

The Northern Sky Variability Survey (NSVS) is a temporal record of the sky over the optical magnitude range from 8 to 15.5. It was conducted in the course of the first-generation Robotic Optical Transient Search Experiment (ROTSE-I) using a robotic system of four comounted unfiltered telephoto lenses equipped with CCD cameras. The survey was conducted from Los Alamos, New Mexico, and primarily covers the entire northern sky. Some data in southern fields between declinations 0{deg} and -38{deg} are also available, although with fewer epochs and noticeably lesser quality. The NSVS contains light curves for approximately 14 million objects. With a 1-yr baseline and typically 100-500 measurements per object, the NSVS is the most extensive record of stellar variability across the bright sky available today. In a median field, bright unsaturated stars attain a point-to-point photometric scatter of ~0.02mag and position errors within 2. At Galactic latitudes |b|<20{deg}, the data quality is limited by severe blending due to the ~14" pixel size. We present basic characteristics of the data set and describe data collection, analysis, and distribution. All NSVS photometric measurements are available for on-line public access from the Sky Database for Objects in Time-Domain (SkyDOT) at Los Alamos National Laboratory. Copies of the full survey photometry may also be requested on tape. (7 data files).

Towards the intrahour forecasting of direct normal irradiance using sky-imaging data.

PubMed

Nou, Julien; Chauvin, Rémi; Eynard, Julien; Thil, Stéphane; Grieu, Stéphane

2018-04-01

Increasing power plant efficiency through improved operation is key in the development of Concentrating Solar Power (CSP) technologies. To this end, one of the most challenging topics remains accurately forecasting the solar resource at a short-term horizon. Indeed, in CSP plants, production is directly impacted by both the availability and variability of the solar resource and, more specifically, by Direct Normal Irradiance (DNI). The present paper deals with a new approach to the intrahour forecasting (the forecast horizon [Formula: see text] is up to [Formula: see text] ahead) of DNI, taking advantage of the fact that this quantity can be split into two terms, i.e. clear-sky DNI and the clear sky index. Clear-sky DNI is forecasted from DNI measurements, using an empirical model (Ineichen and Perez, 2002) combined with a persistence of atmospheric turbidity. Moreover, in the framework of the CSPIMP (Concentrating Solar Power plant efficiency IMProvement) research project, PROMES-CNRS has developed a sky imager able to provide High Dynamic Range (HDR) images. So, regarding the clear-sky index, it is forecasted from sky-imaging data, using an Adaptive Network-based Fuzzy Inference System (ANFIS). A hybrid algorithm that takes inspiration from the classification algorithm proposed by Ghonima et al. (2012) when clear-sky anisotropy is known and from the hybrid thresholding algorithm proposed by Li et al. (2011) in the opposite case has been developed to the detection of clouds. Performance is evaluated via a comparative study in which persistence models - either a persistence of DNI or a persistence of the clear-sky index - are included. Preliminary results highlight that the proposed approach has the potential to outperform these models (both persistence models achieve similar performance) in terms of forecasting accuracy: over the test data used, RMSE (the Root Mean Square Error) is reduced of about [Formula: see text], with [Formula: see text], and [Formula: see text], with [Formula: see text].

Background Light Bluer Than Expected

NASA Image and Video Library

2014-11-06

This plot shows data from the Cosmic Infrared Background Experiment, or CIBER, rockets launched in 2010 and 2012. The experiment measures a diffuse glow of infrared light in the sky, known as the cosmic infrared background.

Adnyamathanha Night Skies

NASA Astrophysics Data System (ADS)

Curnow, Paul

2009-06-01

Aboriginal Australians have been viewing the night skies of Australia for some 45,000 years and possibly much longer. During this time they have been able to develop a complex knowledge of the night sky, the terrestrial environment in addition to seasonal changes. However, few of us in contemporary society have an in-depth knowledge of the nightly waltz of stars above.

Payload crew interface design criteria and techniques. Task 1: Inflight operations and training for payloads. [space shuttles

NASA Technical Reports Server (NTRS)

Carmean, W. D.; Hitz, F. R.

1976-01-01

Guidelines are developed for use in control and display panel design for payload operations performed on the aft flight deck of the orbiter. Preliminary payload procedures are defined. Crew operational concepts are developed. Payloads selected for operational simulations were the shuttle UV optical telescope (SUOT), the deep sky UV survey telescope (DUST), and the shuttle UV stellar spectrograph (SUSS). The advanced technology laboratory payload consisting of 11 experiments was selected for a detailed evaluation because of the availability of operational data and its operational complexity.

Astronomy and Existentialism in Albert Camus' ``The Adulterous Woman''

NASA Astrophysics Data System (ADS)

Garwood, D.

2013-04-01

Camus' short story “An Adulterous Woman” from his collection Exile and the Kingdom narrates the experience of Janine, wife of a French Algerian cloth-trader, who accompanies her husband on a business trip to the Saharan interior at mid-20th century. The desert landscape and its weather play an integral role in the plot. Blending realism and fantasy that borders on science fiction, the narrator characterizes the sky as an animate cosmological energy whose virility is masked by sunlight during the day. Released after sundown and portrayed as a liberator at the climax of the story, the shaman-like night sky descends upon Janine as a shower of stars that leaves her with an existential sense of self. This paper explores themes of astronomy and existentialism that Camus develops through Janine's “adultery” with a cosmological force, supplemented by visual imagery related to the aesthetic and scientific cultural contexts of the story and Camus' era.

A simple analytical formula to compute clear sky total and photosynthetically available solar irradiance at the ocean surface

NASA Technical Reports Server (NTRS)

Frouin, Robert; Lingner, David W.; Gautier, Catherine; Baker, Karen S.; Smith, Ray C.

1989-01-01

A simple but accurate analytical formula was developed for computing the total and the photosynthetically available solar irradiances at the ocean surface under clear skies, which takes into account the processes of scattering by molecules and aerosols within the atmosphere and of absorption by the water vapor, ozone, and aerosols. These processes are parameterized as a function of solar zenith angle, aerosol type, atmospheric visibility, and vertically integrated water-vapor and ozone amounts. Comparisons of the calculated and measured total and photosynthetically available solar irradiances for several experiments in tropical and mid-latitude ocean regions show 39 and 14 Wm/sq m rms errors (6.5 and 4.7 percent of the average measured values) on an hourly time scale, respectively. The proposed forumula is unique in its ability to predict surface solar irradiance in the photosynthetically active spectral interval.

The Python Sky Model: software for simulating the Galactic microwave sky

NASA Astrophysics Data System (ADS)

Thorne, B.; Dunkley, J.; Alonso, D.; Næss, S.

2017-08-01

We present a numerical code to simulate maps of Galactic emission in intensity and polarization at microwave frequencies, aiding in the design of cosmic microwave background experiments. This python code builds on existing efforts to simulate the sky by providing an easy-to-use interface and is based on publicly available data from the WMAP (Wilkinson Microwave Anisotropy Probe) and Planck satellite missions. We simulate synchrotron, thermal dust, free-free and anomalous microwave emission over the whole sky, in addition to the cosmic microwave background, and include a set of alternative prescriptions for the frequency dependence of each component, for example, polarized dust with multiple temperatures and a decorrelation of the signals with frequency, which introduce complexity that is consistent with current data. We also present a new prescription for adding small-scale realizations of these components at resolutions greater than current all-sky measurements. The usefulness of the code is demonstrated by forecasting the impact of varying foreground complexity on the recovered tensor-to-scalar ratio for the LiteBIRD satellite. The code is available at: https://github.com/bthorne93/PySM_public.

A simplified model of all-sky artificial sky glow derived from VIIRS Day/Night band data

NASA Astrophysics Data System (ADS)

Duriscoe, Dan M.; Anderson, Sharolyn J.; Luginbuhl, Christian B.; Baugh, Kimberly E.

2018-07-01

We present a simplified method using geographic analysis tools to predict the average artificial luminance over the hemisphere of the night sky, expressed as a ratio to the natural condition. The VIIRS Day/Night Band upward radiance data from the Suomi NPP orbiting satellite was used for input to the model. The method is based upon a relation between sky glow brightness and the distance from the observer to the source of upward radiance. This relationship was developed using a Garstang radiative transfer model with Day/Night Band data as input, then refined and calibrated with ground-based all-sky V-band photometric data taken under cloudless and low atmospheric aerosol conditions. An excellent correlation was found between observed sky quality and the predicted values from the remotely sensed data. Thematic maps of large regions of the earth showing predicted artificial V-band sky brightness may be quickly generated with modest computing resources. We have found a fast and accurate method based on previous work to model all-sky quality. We provide limitations to this method. The proposed model meets requirements needed by decision makers and land managers of an easy to interpret and understand metric of sky quality.

Mi'kmaq Night Sky Stories; Patterns of Interconnectiveness, Vitality and Nourishment

NASA Astrophysics Data System (ADS)

Harris, P.; Bartlett, C.; Marshall, M.; Marshall, A.

2010-10-01

This article shares some of the experiences of an integrative science team based at Cape Breton University, Canada. Integrative science is defined as "bringing together Indigenous and Western scientific knowledge and ways of knowing" and the team includes Mi'kmaq Elders and educators, Cheryl Bartlett and her Research Associates. Together we worked to rekindle the Mi'kmaq Sky Story, Muin and the Seven Hunters, to produce a DVD of the story as well as a children's book, and then to share it with people throughout Canada and the world. We offer insights into the manner in which night sky stories engender interconnectiveness and interdependability through their cultural, scientific and ecological teachings and so help to revitalise the culture and the individual by feeding all aspects of the human experience (spiritual, emotional, physical and cognitional). We explore the concept of storywork, with emphasis on the relationship between storyteller and listener as a story is told, as well as considering the multi-layered aspect of Indigenous stories.

INDICATIONS OF INTERMEDIATE-SCALE ANISOTROPY OF COSMIC RAYS WITH ENERGY GREATER THAN 57 EeV IN THE NORTHERN SKY MEASURED WITH THE SURFACE DETECTOR OF THE TELESCOPE ARRAY EXPERIMENT

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

Abbasi, R. U.; Abu-Zayyad, T.; Allen, M.

2014-08-01

We have searched for intermediate-scale anisotropy in the arrival directions of ultrahigh-energy cosmic rays with energies above 57 EeV in the northern sky using data collected over a 5 yr period by the surface detector of the Telescope Array experiment. We report on a cluster of events that we call the hotspot, found by oversampling using 20° radius circles. The hotspot has a Li-Ma statistical significance of 5.1σ, and is centered at R.A. = 146.°7, decl. = 43.°2. The position of the hotspot is about 19° off of the supergalactic plane. The probability of a cluster of events of 5.1σ significance, appearingmore » by chance in an isotropic cosmic-ray sky, is estimated to be 3.7 × 10{sup –4} (3.4σ)« less

The Cosmic Background Explorer

NASA Technical Reports Server (NTRS)

Gulkis, Samuel; Lubin, Philip M.; Meyer, Stephan S.; Silverberg, Robert F.

1990-01-01

The Cosmic Background Explorer (CBE), NASA's cosmological satellite which will observe a radiative relic of the big bang, is discussed. The major questions connected to the big bang theory which may be clarified using the CBE are reviewed. The satellite instruments and experiments are described, including the Differential Microwave Radiometer, which measures the difference between microwave radiation emitted from two points on the sky, the Far-Infrared Absolute Spectrophotometer, which compares the spectrum of radiation from the sky at wavelengths from 100 microns to one cm with that from an internal blackbody, and the Diffuse Infrared Background Experiment, which searches for the radiation from the earliest generation of stars.

A new model of the microwave polarized sky for CMB experiments

NASA Astrophysics Data System (ADS)

Hervías-Caimapo, Carlos; Bonaldi, Anna; Brown, Michael L.

2016-10-01

We present a new model of the microwave sky in polarization that can be used to simulate data from cosmic microwave background polarization experiments. We exploit the most recent results from the Planck satellite to provide an accurate description of the diffuse polarized foreground synchrotron and thermal dust emission. Our model can include the two mentioned foregrounds, and also a constructed template of Anomalous Microwave Emission. Several options for the frequency dependence of the foregrounds can be easily selected, to reflect our uncertainties and to test the impact of different assumptions. Small angular scale features can be added to the foreground templates to simulate high-resolution observations. We present tests of the model outputs to show the excellent agreement with Planck and Wilkinson Microwave Anisotropy Probe (WMAP) data. We determine the range within which the foreground spectral indices can be varied to be consistent with the current data. We also show forecasts for a high-sensitivity, high-resolution full-sky experiment such as the Cosmic ORigin Explorer. Our model is released as a PYTHON script that is quick and easy to use, available at http://www.jb.man.ac.uk/chervias.

Host model uncertainties in aerosol radiative forcing estimates: results from the AeroCom prescribed intercomparison study

NASA Astrophysics Data System (ADS)

Stier, P.; Schutgens, N. A. J.; Bian, H.; Boucher, O.; Chin, M.; Ghan, S.; Huneeus, N.; Kinne, S.; Lin, G.; Myhre, G.; Penner, J. E.; Randles, C.; Samset, B.; Schulz, M.; Yu, H.; Zhou, C.

2012-09-01

Simulated multi-model "diversity" in aerosol direct radiative forcing estimates is often perceived as measure of aerosol uncertainty. However, current models used for aerosol radiative forcing calculations vary considerably in model components relevant for forcing calculations and the associated "host-model uncertainties" are generally convoluted with the actual aerosol uncertainty. In this AeroCom Prescribed intercomparison study we systematically isolate and quantify host model uncertainties on aerosol forcing experiments through prescription of identical aerosol radiative properties in nine participating models. Even with prescribed aerosol radiative properties, simulated clear-sky and all-sky aerosol radiative forcings show significant diversity. For a purely scattering case with globally constant optical depth of 0.2, the global-mean all-sky top-of-atmosphere radiative forcing is -4.51 W m-2 and the inter-model standard deviation is 0.70 W m-2, corresponding to a relative standard deviation of 15%. For a case with partially absorbing aerosol with an aerosol optical depth of 0.2 and single scattering albedo of 0.8, the forcing changes to 1.26 W m-2, and the standard deviation increases to 1.21 W m-2, corresponding to a significant relative standard deviation of 96%. However, the top-of-atmosphere forcing variability owing to absorption is low, with relative standard deviations of 9% clear-sky and 12% all-sky. Scaling the forcing standard deviation for a purely scattering case to match the sulfate radiative forcing in the AeroCom Direct Effect experiment, demonstrates that host model uncertainties could explain about half of the overall sulfate forcing diversity of 0.13 W m-2 in the AeroCom Direct Radiative Effect experiment. Host model errors in aerosol radiative forcing are largest in regions of uncertain host model components, such as stratocumulus cloud decks or areas with poorly constrained surface albedos, such as sea ice. Our results demonstrate that host model uncertainties are an important component of aerosol forcing uncertainty that require further attention.

Data indexing techniques for the EUVE all-sky survey

NASA Technical Reports Server (NTRS)

Lewis, J.; Saba, V.; Dobson, C.

1992-01-01

This poster describes techniques developed for manipulating large full-sky data sets for the Extreme Ultraviolet Explorer project. The authors have adapted the quatrilateralized cubic sphere indexing algorithm to allow us to efficiently store and process several types of large data sets, such as full-sky maps of photon counts, exposure time, and count rates. A variation of this scheme is used to index sparser data such as individual photon events and viewing times for selected areas of the sky, which are eventually used to create EUVE source catalogs.

78 FR 11169 - North Sky River Energy, LLC, et al; Notice of Effectiveness of Exempt Wholesale Generator Status

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-15

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket Nos. EG13-6-000, et al] North Sky River Energy, LLC, et al; Notice of Effectiveness of Exempt Wholesale Generator Status Docket Nos. North Sky River Energy, LLC EG13-6-000 Black Bear SO, LLC EG13-7-000 Black Bear Development Holdings...

CFHT's SkyProbe: True Atmospheric Attenuation Measurement in the Telescope Field

NASA Astrophysics Data System (ADS)

Cuillandre, J.-C.; Magnier, E. A.; Isani, S.; Sabin, D.; Knight, W.; Kras, S.; Lai, K.

Developed at the Canada France Hawaii Telescope (CFHT), SkyProbe is a system that allows the direct measurement of the true attenuation by clouds. This measurement is performed approximately once per min, directly on the field viewed by the telescope. It has been possible to make this system relatively inexpensively due to low cost CCD cameras available on the amateur market. A crucial addition to this hardware is the recent availability of a full-sky photometry catalog at the appropriate depth: the Tycho catalog from the Hipparcos mission. A very important element in the SkyProbe data set creation is the automatic data analysis pipeline, Elixir, developed at CFHT for the improved operation of the CFHT wide-field imagers CFH12K and MegaCam. SkyProbe's FITS images are processed in real time, and the pipeline output (a zero point attenuation) provides the current sky transmission to the observers and aids immediate decision making. These measurements are also attached to the archived data, adding a key tool for future use by other astronomers. Specific features of the detector, such as intra pixel quantum efficiency variations, must be taken into consideration since the data are strongly undersampled.

Northern Sky Variability Survey: Public Data Release

NASA Astrophysics Data System (ADS)

Woźniak, P. R.; Vestrand, W. T.; Akerlof, C. W.; Balsano, R.; Bloch, J.; Casperson, D.; Fletcher, S.; Gisler, G.; Kehoe, R.; Kinemuchi, K.; Lee, B. C.; Marshall, S.; McGowan, K. E.; McKay, T. A.; Rykoff, E. S.; Smith, D. A.; Szymanski, J.; Wren, J.

2004-04-01

The Northern Sky Variability Survey (NSVS) is a temporal record of the sky over the optical magnitude range from 8 to 15.5. It was conducted in the course of the first-generation Robotic Optical Transient Search Experiment (ROTSE-I) using a robotic system of four comounted unfiltered telephoto lenses equipped with CCD cameras. The survey was conducted from Los Alamos, New Mexico, and primarily covers the entire northern sky. Some data in southern fields between declinations 0° and -38° are also available, although with fewer epochs and noticeably lesser quality. The NSVS contains light curves for approximately 14 million objects. With a 1 yr baseline and typically 100-500 measurements per object, the NSVS is the most extensive record of stellar variability across the bright sky available today. In a median field, bright unsaturated stars attain a point-to-point photometric scatter of ~0.02 mag and position errors within 2". At Galactic latitudes |b|<20deg, the data quality is limited by severe blending due to the ~14" pixel size. We present basic characteristics of the data set and describe data collection, analysis, and distribution. All NSVS photometric measurements are available for on-line public access from the Sky Database for Objects in Time-Domain (SkyDOT) at Los Alamos National Laboratory. Copies of the full survey photometry may also be requested on tape. Based on observations obtained with the ROTSE-I robotic telescope, which was operated at Los Alamos National Laboratory.

Dark Skies are a Universal Resource: Programs Planned for the International Year of Astronomy

NASA Astrophysics Data System (ADS)

Walker, Constance E.; US IYA Dark Skies Working Group

2008-05-01

The dark night sky is a natural resource that is being lost by much of the world's population. This loss is a growing, serious issue that impacts not only astronomical research, but also human health, ecology, safety, economics and energy conservation. One of the themes of the US Node targeted for the International Year of Astronomy (IYA) is "Dark Skies are a Universal Resource". The goal is to raise public awareness of the impact of artificial lighting on local environments by getting people involved locally in a variety of dark skies-related events. To reach this goal, activities are being developed that: 1) Teach about dark skies using new technology (e.g., an activity-based planetarium show on DVD, podcasting, social networking) 2) Provide thematic events on light pollution at star parties and observatory open houses (Dark Skies Teaching Sites, Astronomy Nights in the (National) Parks, Sidewalk Astronomy Nights) 3) Organize events in the arts (e.g., a photography contest) 4) Involve citizen-scientists in unaided-eye and digital-meter star counting programs (e.g., GLOBE at Night, "How Many Stars?” and the Great World Wide Star Count) and 5) Raise awareness about the link between light pollution and public health, economic issues, ecological consequences, energy conservation, safety and security (e.g., The Great Switch Out, Earth Hour, National Dark Skies Week, traveling exhibits and a 6-minute video tutorial on lighting issues). To deliver these programs, strategic networks have been established with the ASP's Night Sky Network's astronomy clubs, Astronomy from the Ground Up's science and nature centers and the Project and Family ASTRO programs, as well as the International Dark-Sky Association, GLOBE and the Astronomical League, among others. The poster presentation will outline the activities being developed, the plans for funding, implementation, marketing and the connections to the global cornerstone IYA project, "Dark Skies Awareness".

Paddling the Big Sky: Reflections on place-based education and experience

Treesearch

Phil Mullins; Patrick T. Maher

2007-01-01

Paddling the Big Sky began as many expeditions do: out of past trips and in the stories, banter and daydreams of a group of friends. The journey, by canoe, departed from the foothills of the Rocky Mountains, stretched over 2,800 km (1,740 miles), crossed prairie, the width of the boreal forest, and then the “barren lands.” It included a 29-day university outdoor...

Dark Skies Awareness Programs for the International Year of Astronomy

NASA Astrophysics Data System (ADS)

Walker, C. E.; Pompea, S. M.

2008-12-01

The loss of a dark night sky as a natural resource is a growing concern. It impacts not only astronomical research, but also our environment in terms of ecology, health, safety, economics and energy conservation. For this reason, "Dark Skies are a Universal Resource" is a cornerstone project for the U.S. International Year of Astronomy (IYA) program in 2009. Its goal is to raise public awareness of the impact of artificial lighting on local environments by getting people involved in a variety of dark skies-related programs. These programs focus on citizen-scientist sky-brightness monitoring programs, a planetarium show, podcasting, social networking, a digital photography contest, the Good Neighbor Lighting Program, Earth Hour, National Dark Skies Week, a traveling exhibit, a video tutorial, Dark Skies Discovery Sites, Astronomy Nights in the (National) Parks, Sidewalk Astronomy, and a Quiet Skies program. Many similar programs are available internationally through the "Dark Skies Awareness" Global Cornerstone Project. Working groups for both the national and international dark skies cornerstone projects are being chaired by the National Optical Astronomy Observatory (NOAO). The presenters from NOAO will provide the "know-how" and the means for session participants to become community advocates in promoting Dark Skies programs as public events at their home institutions. Participants will be able to get information on jump-starting their education programs through the use of well-developed instructional materials and kits. For more information, visit http://astronomy2009.us/darkskies/ and http://www.darkskiesawareness.org/.

Search for extraterrestrial intelligence/High Resolution Microwave Survey team member

NASA Technical Reports Server (NTRS)

Steffes, Paul G.

1994-01-01

This final report summarizes activities conducted during the three years of the NASA High Resolution Microwave Survey (HRMS). With primary interest in the Sky Survey activity, the principal investigator attended nine Working Group meetings and traveled independently to conduct experiments or present results at other meetings. The major activity involved evaluating the effects of spaceborne radio frequency interference (RFI) on both the SETI sky survey and targeted search. The development of a database of all unclassified earth or biting and deep space transmitters, along with accompanying search software, was a key accomplishment. The software provides information about potential sources of interference and gives complete information regarding the frequencies, positions and levels of interference generated by the spacecraft. A complete description of this search system (called HRS, or HRMS RFI Search) is provided. Other accomplishments include development of a 32,000 channel Fast-Fourier-Transform Spectrum analyzer for use in studies of interference from satellites and in a 1.4 mm SETI observational study. The latest revision of HRS has now been distributed to the extended radio astronomy and SETI community.

Dark Skies Ahead? Activities to Raise Awareness during the International Year of Astronomy

NASA Astrophysics Data System (ADS)

Walker, Constance E.; Isbell, D.; Pompea, S.

2007-12-01

"Dark Skies as a Universal Resource” is one of 7 themes targeted for the International Year of Astronomy in 2009. The theme's goal is to raise public awareness of the impact of artificial lighting on local environments and the ongoing loss of a dark night sky as a natural resource for much of the world's population. To reach this goal, activities are being developed which highlight dark skies preservation issues 1) through new technology (e.g., programs at planetaria, blogging, podcasting); 2) at events such as star parties and observatory open houses; 3) in arts, entertainment and storytelling (e.g., art competitions, documentaries, lectures, native American traditions); 4) through unaided-eye and digital-meter star count programs involving citizen-scientists; and 5) by relating them to public health, economic issues, ecological consequences, energy conservation, safety and security. A centerpiece of the Dark Skies theme is the unaided-eye and digital-meter versions of the GLOBE at Night program. The unaided-eye version directs citizen-scientists on how to observe and record the brightness of the night sky by matching its appearance toward the constellation of Orion with one of 7 stellar maps of different limiting magnitudes. For the "digital” version, low-cost meters are used by citizen-scientists to measure the integrated sky brightness. Data sets and maps of both versions are supplied on-line for further capstone activities. In the presentation, we will outline the activities being developed as well as plans for funding, implementation, marketing and the connections to the global cornerstone IYA project, "Dark Skies Awareness".

The National Solar Radiation Database (NSRDB): A Brief Overview

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

Habte, Aron M; Sengupta, Manajit; Lopez, Anthony

This poster presents a high-level overview of the National Solar Radiation Database (NSRDB). The NSRDB uses the physics-based model (PSM), which was developed using: adapted PATMOS-X model for cloud identification and properties, REST-2 model for clear-sky conditions, and NREL's Fast All-sky Radiation Model for Solar Applications (FARMS) for cloudy-sky Global Horizontal Irradiance (GHI) solar irradiance calculations.

An Innovative Collaboration on Dark Skies Education

NASA Astrophysics Data System (ADS)

Walker, Constance E.; Mayer, M.; EPO Students, NOAO

2011-01-01

Dark night skies are being lost all over the globe, and hundreds of millions of dollars of energy are being wasted in the process.. Improper lighting is the main cause of light pollution. Light pollution is a concern on many fronts, affecting safety, energy conservation, cost, human health, and wildlife. It also robs us of the beauty of viewing the night sky. In the U.S. alone, over half of the population cannot see the Milky Way from where they live. To help address this, the National Optical Astronomy Observatory Education and Public Outreach (NOAO EPO) staff created two programs: Dark Skies Rangers and GLOBE at Night. Through the two programs, students learn about the importance of dark skies and experience activities that illustrate proper lighting, light pollution's effects on wildlife and how to measure the darkness of their skies. To disseminate the programs locally in an appropriate yet innovative venue, NOAO partnered with the Cooper Center for Environmental Learning in Tucson, Arizona. Operated by the largest school district in Tucson and the University of Arizona College of Education, the Cooper Center educates thousands of students and educators each year about ecology, science, and the beauty and wonders of the Sonoran Desert. During the first academic year (2009-2010), we achieved our goal of reaching nearly 20 teachers in 40 classrooms of 1000 students. We gave two 3-hour teacher-training sessions and provided nineteen 2.5-hour on-site evening sessions on dark skies activities for the students of the teachers trained. One outcome of the program was the contribution of 1000 "GLOBE at Night 2010” night-sky brightness measurements by Tucson students. Training sessions at similar levels are continuing this year. The partnership, planning, lesson learned, and outcomes of NOAO's collaboration with the environmental center will be presented.

NASA SETI microwave observing project: Sky Survey element

NASA Technical Reports Server (NTRS)

Klein, M. J.

1991-01-01

The SETI Sky Survey Observing Program is one of two complimentary strategies that NASA plans to use in its microwave Search for Extraterrestrial Intelligence (SETI). The primary objective of the sky survey is to search the entire sky over the frequency range of 1.0 to 10.0 GHz for evidence of narrow band signals of extraterrestrial intelligent origin. Frequency resolutions of 30 Hz or narrower will be used across the entire band. Spectrum analyzers with upwards of ten million channels are required to keep the survey time approximately 6 years. Data rates in excess of 10 megabits per second will be generated in the data taking process. Sophisticated data processing techniques will be required to determine the ever changing receiver baselines, and to detect and archive potential SETI signals. Existing radio telescopes, including several of NASA's Deep Space Network (DSN) 34 meter antennas located at Goldstone, CA and Tidbinbilla, Australia will be used for the observations. The JPL has the primary responsibility to develop and carry out the sky survey. In order to lay the foundation for the full scale SETI Sky Survey, a prototype system is being developed at the JPL. The system will be installed at the new 34-m high efficiency antenna at the Deep Space Station (DSS) 13 research and development station, Goldstone, CA, where it will be used to initiate the observational phase of the NASA SETI Sky Survey. It is anticipated that the early observations will be useful to test signal detection algorithms, scan strategies, and radio frequency interference rejection schemes. The SETI specific elements of the prototype system are: (1) the Wide Band Spectrum Analyzer (WBSA); a 2-million channel fast Fourier transformation (FFT) spectrum analyzer which covers an instantaneous bandpass of 40 MHz; (2) the signal detection processor; and (3) the SETI Sky Survey Manager, a network-based C-language environment that provides observatory control, performs data acquisition and analysis algorithms. A high level description of the prototype hardware and software systems will be given and the current status of the system development will be reported.

Skylab: Program Description

NASA Technical Reports Server (NTRS)

1971-01-01

In 1973 three Americans will embark on the first of a series of Earth orbiting missions using Skylab, the first United States vehicle created specifically to enable man to live and work in space for extended periods. Sky lab is a program dedicated to the use of space and its unique environment and vantage point to increase our knowledge and understanding of the Earth's importance to man's well-being and man's influence on Earth's ecology. Sky lab will also be a major step in manned space flight. Habitation by the first crew will double our previous man-in-space duration (Gemini VII) and the second visit will redouble that duration. It will, in effect, create a bridge between the development flights of the 60s and the long duration operational space flights of the future. To accomplish its mission, Sky lab will be placed in Earth orbit and will be visited and inhabited by three different crews during an eight-month period. While successfully inhabiting and operating the vehicle for one- and two-month continuous periods, these crews will obtain data in areas pertinent to the man/Earth relationship and to long duration space flight. Data will be acquired by Skylab primarily through the conduct of "experiments." Four categories of investigation are planned. These are summarized in the following paragraphs.

Modelling and Display of the Ultraviolet Sky

NASA Astrophysics Data System (ADS)

Daniels, J.; Henry, R.; Murthy, J.; Allen, M.; McGlynn, T. A.; Scollick, K.

1994-12-01

A computer program is currently under development to model in 3D - one dimension of which is wavelength - all the known and major speculated sources of ultraviolet (900 A - 3100 A ) radiation over the celestial sphere. The software is being written in Fortran 77 and IDL and currently operates under IRIX (the operating system of the Silicon Graphics Iris Machine); all output models are in FITS format. Models along with display software will become available to the astronomical community. The Ultraviolet Sky Model currently includes the Zodiacal Light, Point Sources of Emission, and the Diffuse Galactic Light. The Ultraviolet Sky Model is currently displayed using SkyView: a package under development at NASA/ GSFC, which allows users to retrieve and display publically available all-sky astronomical survey data (covering many wavebands) over the Internet. We present a demonstration of the SkyView display of the Ultraviolet Model. The modelling is a five year development project: the work illustrated here represents product output at the end of year one. Future work includes enhancements to the current models and incorporation of the following models: Galactic Molecular Hydrogen Fluorescence; Galactic Highly Ionized Atomic Line Emission; Integrated Extragalactic Light; and speculated sources in the intergalactic medium such as Ionized Plasma and radiation from Non-Baryonic Particle Decay. We also present a poster which summarizes the components of the Ultraviolet Sky Model and outlines a further package that will be used to display the Ultraviolet Model. This work is supported by United States Air Force Contract F19628-93-K-0004. Dr J. Daniels is supported with a post-doctoral Fellowship from the Leverhulme Foundation, London, United Kingdom. We are also grateful for the encouragement of Dr Stephen Price (Phillips Laboratory, Hanscomb Air Force Base, MA)

Flying the Infrared Skies: An Authentic SOFIA Educator Experience

NASA Astrophysics Data System (ADS)

Manning, J. G.

2015-11-01

The NASA/DLR Stratospheric Observatory for Infrared Astronomy (SOFIA) flagship education effort is its Airborne Astronomy Ambassadors (AAA) program. The program flies teams of teachers on SOFIA research flights as part of an educator professional development effort enabling these teachers to experience first-hand the workings of the airborne observatory, to interact with scientists and technologists, to observe research in progress and how scientists use technology—all in support of national STEM goals. The presenter will share his own experience as an EPO escort on a recent SOFIA flight including two educator teams, providing a first-hand account of how an “authentic” science experience can exploit unique NASA assets to improve science teaching, inspire students, inform local communities, and contribute to the elevation of public science literacy.

Climate Change Education in Protected Areas: Highlights from the Earth to Sky NASA-NPS-USFWS Partnership

NASA Astrophysics Data System (ADS)

Davis, A.; Morris, J.; Paglierani, R.

2009-12-01

National Parks, Hatcheries, Refuges, and other protected lands provide ideal settings for communicating the immediate and obvious effects of climate change, from rapidly melting glaciers, increased intensity and length of fire seasons, to flooding of archeological and historical treasures. Our nation's protected areas demonstrate clearly that climate change is happening now, and the impacts are affecting us all. Highlights of interpretive, educational and informational products presented in these sites, and developed through the Earth to Sky (ETS) partnership are described. The visiting public in our nation's parks, refuges, cultural sites and other protected lands wants to learn more about climate change, and is asking questions—often, complex questions. A broad array of educational programs and media are delivered in these unique settings, to diverse audiences. To be good "honest brokers" of the best information, staff needs access to accurate, up-to-date data, descriptions, analysis, and imagery that make the issues understandable. Pairing real world experiences of climate effects such as glacial retreat or beetle infestations, with NASA’s unique planetary perspective provides opportunities to link local, regional, and global effects in the minds and hearts of the public and students. The perspective afforded by such linkages can create powerful and long lasting impressions, and will likely provoke further learning about this topic. About Earth to Sky Earth to Sky is a partnership between NASA's Space and Earth Science disciplines, the US Fish and Wildlife Service (USFWS), and the National Park Service (NPS). The partnership actively fosters collaborative work between the science and interpretation/education communities of NPS, USFWS, and NASA, centering around a series of professional development workshops aimed at informal educators. The workshops weave NASA content with NPS and USFWS interpretation and environmental education methodology, and use best practices in professional development. The partnership is funded by NASA, with in-kind contributions from NPS and USFWS. Earth to Sky III: Interpreting Climate Change, held in Jan. 2009, featured over 25 NASA scientists and education specialists who presented to 30 NPS rangers and several attendees from U.S. Fish and Wildlife Service (USFWS), and other informal education groups. Participant's action plans include Junior Ranger programs; pod casts; a public outreach campaign at one of our nation’s leading zoos; creation of talking points for staff at a variety of sites; use of the Landsat satellite's 35+ year record of changes in western parks for public programs, a site bulletin and a podcast; workshops for teachers; new exhibits in visitor centers; curriculum-based educational programming; fact sheets; training for USFWS regional staff; and of course standard ranger campfire and slide programs. Earth to Sky IV: Building Climate Literacy for Informal Educators will be held in Feb. 2010. A pilot course on Interpreting Climate Change is under development, and will be offered in September of 2011 at the USFWS’ National Conservation Training Center in Shepherdstown, WV.

The Footprint Database and Web Services of the Herschel Space Observatory

NASA Astrophysics Data System (ADS)

Dobos, László; Varga-Verebélyi, Erika; Verdugo, Eva; Teyssier, David; Exter, Katrina; Valtchanov, Ivan; Budavári, Tamás; Kiss, Csaba

2016-10-01

Data from the Herschel Space Observatory is freely available to the public but no uniformly processed catalogue of the observations has been published so far. To date, the Herschel Science Archive does not contain the exact sky coverage (footprint) of individual observations and supports search for measurements based on bounding circles only. Drawing on previous experience in implementing footprint databases, we built the Herschel Footprint Database and Web Services for the Herschel Space Observatory to provide efficient search capabilities for typical astronomical queries. The database was designed with the following main goals in mind: (a) provide a unified data model for meta-data of all instruments and observational modes, (b) quickly find observations covering a selected object and its neighbourhood, (c) quickly find every observation in a larger area of the sky, (d) allow for finding solar system objects crossing observation fields. As a first step, we developed a unified data model of observations of all three Herschel instruments for all pointing and instrument modes. Then, using telescope pointing information and observational meta-data, we compiled a database of footprints. As opposed to methods using pixellation of the sphere, we represent sky coverage in an exact geometric form allowing for precise area calculations. For easier handling of Herschel observation footprints with rather complex shapes, two algorithms were implemented to reduce the outline. Furthermore, a new visualisation tool to plot footprints with various spherical projections was developed. Indexing of the footprints using Hierarchical Triangular Mesh makes it possible to quickly find observations based on sky coverage, time and meta-data. The database is accessible via a web site http://herschel.vo.elte.hu and also as a set of REST web service functions, which makes it readily usable from programming environments such as Python or IDL. The web service allows downloading footprint data in various formats including Virtual Observatory standards.

Improved Estimates of Clear Sky Longwave Flux and Application to the Tropical Greenhouse Effect

NASA Technical Reports Server (NTRS)

Collins, W. D.

1997-01-01

The first objective of this investigation is to eliminate the clear-sky offset introduced by the scene-identification procedures developed for the Earth Radiation Budget Experiment (ERBE). Estimates of this systematic bias range from 10 to as high as 30 W/sq m. The initial version of the ScaRaB data is being processed with the original ERBE algorithm. Since the ERBE procedure for scene identification is based upon zonal flux averages, clear scenes with longwave emission well below the zonal mean value are mistakenly classified as cloudy. The erroneous classification is more frequent in regions with deep convection and enhanced mid- and upper-tropospheric humidity. We will develop scene identification parameters with zonal and/or time dependence to reduce or eliminate the bias in the clear- sky data. The modified scene identification procedure could be used for the ScaRaB-specific version of the Earth-radiation products. The second objective is to investigate changes in the clear-sky Outgoing Longwave Radiation (OLR) associated with decadal variations in the tropical and subtropical climate. There is considerable evidence for a shift in the climate state starting in approximately 1977. The shift is accompanied by higher SSTs in the equatorial Pacific, increased tropical convection, and higher values of atmospheric humidity. Other evidence indicates that the humidity in the tropical troposphere has been steadily increasing over the last 30 years. It is not known whether the atmospheric greenhouse effect has increased during this period in response to these changes in SST and precipitable water. We will investigate the decadal-scale fluctuations in the greenhouse effect using Nimbus-7, ERBE, and ScaRaB measurements spaning 1979 to the present. The data from the different satellites will be intercalibrated by comparison with model calculations based upon ship radiosonde observations. The fluxes calculated from the radiation model will also be used for validation of the ScaRaB fluxes.

Site Protection Program and Progress Report of Ali Observatory, Tibet

NASA Astrophysics Data System (ADS)

Yao, Yongqiang; Zhou, Yunhe; Wang, Xiaohua; He, Jun; Zhou, Shu

2015-08-01

The Ali observatory, Tibet, is a promising new site identified through ten year site survey over west China, and it is of significance to establish rules of site protection during site development. The site protection program is described with five aspects: site monitoring, technical support, local government support, specific organization, and public education. The long-term sky brightness monitoring is ready with site testing instruments and basic for light pollution measurement; the monitoring also includes directions of main light sources, providing periodical reports and suggestions for coordinating meetings. The technical supports with institutes and manufacturers help to publish lighting standards and replace light fixtures; the research pays special attention to the blue-rich sources, which impact the important application of high altitude sites. An official leading group towards development and protection of astronomical resources has been established by Ali government; one of its tasks is to issue regulations against light pollution, including special restrictions of airport, mine, and winter heating, and to supervise lighting inspection and rectification. A site protection office under the official group and local astronomical society are organized by Ali observatory; the office can coordinate in government levels and promote related activities. A specific website operated by the protection office releases activity propaganda, evaluation results, and technical comparison with other observatories. Both the site protection office and Ali observatory take responsibility for public education, including popular science lectures, light pollution and energy conservation education. Ali Night Sky Park has been constructed and opens in 2014, and provides a popular place and observational experience. The establishment of Ali Observatory and Night Sky Park brings unexpected social influence, and the starry sky trip to Ali becomes a new format of culture-oriented travels in China. The related news reports and network propaganda have drawn attention of national top leadership, instructing to further investigate national support policies.

Validation and Improvement of CERES Surface Radiation Budget Algorithms: Extension of Dusty and Cloudy Scenes

NASA Technical Reports Server (NTRS)

Ramanathan, V.; Inamdar, Anand K.

2005-01-01

Our main task was to validate and improve the generation of surface long wave fluxes from the CERES TOA window channel flux measurements. We completed this task successfully for the clear sky fluxes in the presence of aerosols including dust during the first year of the project. The algorithm we developed for CERES was remarkably successful for clear sky fluxes and we have no further tasks that need to be performed past the requested termination date of December 31, 2004. We found that the information contained in the TOA fluxes was not sufficient to improve upon the current CERES algorithm for cloudy sky fluxes. Given this development and given our success in clear sky fluxes, we do not see any reason to continue our validation work beyond what we have completed. Specific details are given.

An infrared sky model based on the IRAS point source data

NASA Technical Reports Server (NTRS)

Cohen, Martin; Walker, Russell; Wainscoat, Richard; Volk, Kevin; Walker, Helen; Schwartz, Deborah

1990-01-01

A detailed model for the infrared point source sky is presented that comprises geometrically and physically realistic representations of the galactic disk, bulge, spheroid, spiral arms, molecular ring, and absolute magnitudes. The model was guided by a parallel Monte Carlo simulation of the Galaxy. The content of the galactic source table constitutes an excellent match to the 12 micrometer luminosity function in the simulation, as well as the luminosity functions at V and K. Models are given for predicting the density of asteroids to be observed, and the diffuse background radiance of the Zodiacal cloud. The model can be used to predict the character of the point source sky expected for observations from future infrared space experiments.

Sky Compass Orientation in Desert Locusts-Evidence from Field and Laboratory Studies.

PubMed

Homberg, Uwe

2015-01-01

Locusts are long-range migratory insects. At high population density, immature animals form marching hopper bands while adults take off and form huge swarms of millions of animals. At low population densities animals are solitarious, but likewise migrate, mostly during the night. Numerous studies aimed at predicting locust infestations showed that migrations both as hopper bands and as adults are largely downwind following seasonal shifts of the tropical convergence zone taking the animals to areas of rainfall. Only a few studies provided evidence for active orientation mechanisms, including the involvement of a sun compass. This scarcity of evidence stands in contrast to recent neurobiological data showing sophisticated neuronal adaptations suited for sky compass navigation. These include a special dorsal eye region with photoreceptors suited to analyze the polarization pattern of the sky and a system of topographically arranged sky compass neurons in the central complex of the brain. Laboratory experiments, moreover, demonstrated polarotaxis in tethered flying animals. The discrepancy of these findings call for more rigorous field studies on active orientation mechanisms in locusts. It remains to be shown how locusts use their internal sky compass during mass migrations and what role it plays to guide solitarious locusts in their natural habitat.

Measuring night sky brightness: methods and challenges

NASA Astrophysics Data System (ADS)

Hänel, Andreas; Posch, Thomas; Ribas, Salvador J.; Aubé, Martin; Duriscoe, Dan; Jechow, Andreas; Kollath, Zoltán; Lolkema, Dorien E.; Moore, Chadwick; Schmidt, Norbert; Spoelstra, Henk; Wuchterl, Günther; Kyba, Christopher C. M.

2018-01-01

Measuring the brightness of the night sky has become an increasingly important topic in recent years, as artificial lights and their scattering by the Earth's atmosphere continue spreading around the globe. Several instruments and techniques have been developed for this task. We give an overview of these, and discuss their strengths and limitations. The different quantities that can and should be derived when measuring the night sky brightness are discussed, as well as the procedures that have been and still need to be defined in this context. We conclude that in many situations, calibrated consumer digital cameras with fisheye lenses provide the best relation between ease-of-use and wealth of obtainable information on the night sky. While they do not obtain full spectral information, they are able to sample the complete sky in a period of minutes, with colour information in three bands. This is important, as given the current global changes in lamp spectra, changes in sky radiance observed only with single band devices may lead to incorrect conclusions regarding long term changes in sky brightness. The acquisition of all-sky information is desirable, as zenith-only information does not provide an adequate characterization of a site. Nevertheless, zenith-only single-band one-channel devices such as the "Sky Quality Meter" continue to be a viable option for long-term studies of night sky brightness and for studies conducted from a moving platform. Accurate interpretation of such data requires some understanding of the colour composition of the sky light. We recommend supplementing long-term time series derived with such devices with periodic all-sky sampling by a calibrated camera system and calibrated luxmeters or luminance meters.

Search for GRB related prompt optical emission and other fast varying objects with ``Pi of the Sky'' detector

NASA Astrophysics Data System (ADS)

Ćwiok, M.; Dominik, W.; Małek, K.; Mankiewicz, L.; Mrowca-Ciułacz, J.; Nawrocki, K.; Piotrowski, L. W.; Sitek, P.; Sokołowski, M.; Wrochna, G.; Żarnecki, A. F.

2007-06-01

Experiment “Pi of the Sky” is designed to search for prompt optical emission from GRB sources. 32 CCD cameras covering 2 steradians will monitor the sky continuously. The data will be analysed on-line in search for optical flashes. The prototype with 2 cameras operated at Las Campanas (Chile) since 2004 has recognised several outbursts of flaring stars and has given limits for a few GRB.

Local short-term variability in solar irradiance

NASA Astrophysics Data System (ADS)

Lohmann, Gerald M.; Monahan, Adam H.; Heinemann, Detlev

2016-05-01

Characterizing spatiotemporal irradiance variability is important for the successful grid integration of increasing numbers of photovoltaic (PV) power systems. Using 1 Hz data recorded by as many as 99 pyranometers during the HD(CP)2 Observational Prototype Experiment (HOPE), we analyze field variability of clear-sky index k* (i.e., irradiance normalized to clear-sky conditions) and sub-minute k* increments (i.e., changes over specified intervals of time) for distances between tens of meters and about 10 km. By means of a simple classification scheme based on k* statistics, we identify overcast, clear, and mixed sky conditions, and demonstrate that the last of these is the most potentially problematic in terms of short-term PV power fluctuations. Under mixed conditions, the probability of relatively strong k* increments of ±0.5 is approximately twice as high compared to increment statistics computed without conditioning by sky type. Additionally, spatial autocorrelation structures of k* increment fields differ considerably between sky types. While the profiles for overcast and clear skies mostly resemble the predictions of a simple model published by , this is not the case for mixed conditions. As a proxy for the smoothing effects of distributed PV, we finally show that spatial averaging mitigates variability in k* less effectively than variability in k* increments, for a spatial sensor density of 2 km-2.

The effect of spatial and spectral heterogeneity of ground-based light sources on night-sky radiances

NASA Astrophysics Data System (ADS)

Kocifaj, M.; Aubé, M.; Kohút, I.

2010-12-01

Nowadays, light pollution is a permanent problem at many observatories around the world. Elimination of excessive lighting during the night is not only about reduction of the total luminous power of ground-based light sources, but also involves experimenting with the spectral features of single lamps. Astronomical photometry is typically made at specific wavelengths, and thus the analysis of the spectral effects of light pollution is highly important. Nevertheless, studies on the spectral behaviour of night light are quite rare. Instead, broad-band or integral quantities (such as sky luminance) are preferentially measured and modelled. The knowledge of night-light spectra is necessary for the proper interpretation of narrow-band photometry data. In this paper, the night-sky radiances in the nominal spectral lines of the B (445 nm) and V (551 nm) filters are determined numerically under clear-sky conditions. Simultaneously, the corresponding sky-luminance patterns are computed and compared against the spectral radiances. It is shown that spectra, patterns and distances of the most important light sources (towns) surrounding an observatory are essential for determining the light pollution levels. In addition, the optical characteristics of the local atmosphere can change the angular behaviour of the sky radiance or luminance. All these effects are evaluated for two Slovakian observatories: Stará Lesná and Vartovka.

Astronomy Education Under Dark Skies

NASA Astrophysics Data System (ADS)

Cecylia Molenda-Zakowicz, Joanna

2015-08-01

We have been providing professional support for the high school students and the astronomy teachers since 2007. Our efforts include organizing astronomy events that take from several hours, like, e.g., watching the transit of Venus, to several days, like the workshops organized in the framework of the projects 'School Workshops on Astronomy' (SWA) and 'Wygasz'.The SWA and Wygasz workshops include presentations by experts in astronomy and space science research, presentations prepared by students being supervised by those experts, hands-on interactive experience in the amateur astrophotography, various pencil-and-paper exercises, and other practical activities. We pay particular attention to familiarize the teachers and students with the idea and the necessity of protecting the dark sky. The format of these events allows also for some time for teachers to share ideas and best practices in teaching astronomy.All those activities are organized either in the Izera Dark-Sky Park in Poland or in other carefuly selected locations in which the beauty of the dark night sky can be appreciated.

Moon orientation in adult and young sandhoppers under artificial light.

PubMed

Ugolini, Alberto; Boddi, Vieri; Mercatelli, Luca; Castellini, Carlo

2005-10-22

Our experiments, carried out at night and during the day on adults and laboratory-born young of the sandhopper Talitrus saltator, deal with the identification and use of the moon as an orientating factor. Sandhoppers were released in an apparatus (a Plexiglas dome) that produced a scenario similar to the natural one (with artificial sky, moon or sun illuminated at different intensities). When tested at night, the adult and young sandhoppers used the artificial moon like the natural one, independently of the intensity of illumination of the artificial sky and moon. In other words, sandhoppers tested at night always identified the artificial moon as the moon and never as the sun. In daytime releases, the seaward orientation failed at low intensities of artificial sky and sun illumination (3.07 and 1.55 microW cm2, respectively), whereas the sun compass was used effectively at higher levels of artificial sun and sky illumination. The innate ability of moon compass orientation in inexpert young sandhoppers was demonstrated even under artificial light.

Constraints on the FRB rate at 700-900 MHz

NASA Astrophysics Data System (ADS)

Connor, Liam; Lin, Hsiu-Hsien; Masui, Kiyoshi; Oppermann, Niels; Pen, Ue-Li; Peterson, Jeffrey B.; Roman, Alexander; Sievers, Jonathan

2016-07-01

Estimating the all-sky rate of fast radio bursts (FRBs) has been difficult due to small-number statistics and the fact that they are seen by disparate surveys in different regions of the sky. In this paper we provide limits for the FRB rate at 800 MHz based on the only burst detected at frequencies below 1.4 GHz, FRB 110523. We discuss the difficulties in rate estimation, particularly in providing an all-sky rate above a single fluence threshold. We find an implied rate between 700 and 900 MHz that is consistent with the rate at 1.4 GHz, scaling to 6.4^{+29.5}_{-5.0} × 10^3 sky-1 d-1 for an HTRU-like survey. This is promising for upcoming experiments below a GHz like CHIME and UTMOST, for which we forecast detection rates. Given 110523's discovery at 32σ with nothing weaker detected, down to the threshold of 8σ, we find consistency with a Euclidean flux distribution but disfavour steep distributions, ruling out γ > 2.2.

SETI prototype system for NASA's Sky Survey microwave observing project - A progress report

NASA Technical Reports Server (NTRS)

Klein, M. J.; Gulkis, S.; Wilck, H. C.

1990-01-01

Two complementary search strategies, a Targeted Search and a Sky Survey, are part of NASA's SETI microwave observing project scheduled to begin in October of 1992. The current progress in the development of hardware and software elements of the JPL Sky Survey data processing system are presented. While the Targeted Search stresses sensitivity allowing the detection of either continuous or pulsed signals over the 1-3 GHz frequency range, the Sky Survey gives up sensitivity to survey the 99 percent of the sky that is not covered by the Targeted Search. The Sky Survey spans a larger frequency range from 1-10 GHz. The two searches will deploy special-purpose digital signal processing equipment designed and built to automate the observing and data processing activities. A two-million channel digital wideband spectrum analyzer and a signal processor system will serve as a prototype for the SETI Sky Survey processor. The design will permit future expansion to meet the SETI requirement that the processor concurrently search for left and right circularly polarized signals.

The Development of the Spanish Fireball Network Using a New All-Sky CCD System

NASA Astrophysics Data System (ADS)

Trigo-Rodríguez, J. M.; Castro-Tirado, A. J.; Llorca, J.; Fabregat, J.; Martínez, V. J.; Reglero, V.; Jelínek, M.; Kubánek, P.; Mateo, T.; Postigo, A. De Ugarte

2004-12-01

We have developed an all-sky charge coupled devices (CCD) automatic system for detecting meteors and fireballs that will be operative in four stations in Spain during 2005. The cameras were developed following the BOOTES-1 prototype installed at the El Arenosillo Observatory in 2002, which is based on a CCD detector of 4096 × 4096 pixels with a fish-eye lens that provides an all-sky image with enough resolution to make accurate astrometric measurements. Since late 2004, a couple of cameras at two of the four stations operate for 30 s in alternate exposures, allowing 100% time coverage. The stellar limiting magnitude of the images is +10 in the zenith, and +8 below ~ 65° of zenithal angle. As a result, the images provide enough comparison stars to make astrometric measurements of faint meteors and fireballs with an accuracy of ~ 2°arcminutes. Using this prototype, four automatic all-sky CCD stations have been developed, two in Andalusia and two in the Valencian Community, to start full operation of the Spanish Fireball Network. In addition to all-sky coverage, we are developing a fireball spectroscopy program using medium field lenses with additional CCD cameras. Here we present the first images obtained from the El Arenosillo and La Mayora stations in Andalusia during their first months of activity. The detection of the Jan 27, 2003 superbolide of ± 17 ± 1 absolute magnitude that overflew Algeria and Morocco is an example of the detection capability of our prototype.

Gamma-sky.net: Portal to the gamma-ray sky

NASA Astrophysics Data System (ADS)

Voruganti, Arjun; Deil, Christoph; Donath, Axel; King, Johannes

2017-01-01

http://gamma-sky.net is a novel interactive website designed for exploring the gamma-ray sky. The Map View portion of the site is powered by the Aladin Lite sky atlas, providing a scalable survey image tesselated onto a three-dimensional sphere. The map allows for interactive pan and zoom navigation as well as search queries by sky position or object name. The default image overlay shows the gamma-ray sky observed by the Fermi-LAT gamma-ray space telescope. Other survey images (e.g. Planck microwave images in low/high frequency bands, ROSAT X-ray image) are available for comparison with the gamma-ray data. Sources from major gamma-ray source catalogs of interest (Fermi-LAT 2FHL, 3FGL and a TeV source catalog) are overlaid over the sky map as markers. Clicking on a given source shows basic information in a popup, and detailed pages for every source are available via the Catalog View component of the website, including information such as source classification, spectrum and light-curve plots, and literature references. We intend for gamma-sky.net to be applicable for both professional astronomers as well as the general public. The website started in early June 2016 and is being developed as an open-source, open data project on GitHub (https://github.com/gammapy/gamma-sky). We plan to extend it to display more gamma-ray and multi-wavelength data. Feedback and contributions are very welcome!

Reconstructing the Sky Location of Gravitational-Wave Detected Compact Binary Systems: Methodology for Testing and Comparison

NASA Technical Reports Server (NTRS)

Sidney, T.; Aylott, B.; Christensen, N.; Farr, B.; Farr, W.; Feroz, F.; Gair, J.; Grover, K.; Graff, P.; Hanna, C.;

Reconstructing the sky location of gravitational-wave detected compact binary systems: Methodology for testing and comparison

NASA Astrophysics Data System (ADS)

Sidery, T.; Aylott, B.; Christensen, N.; Farr, B.; Farr, W.; Feroz, F.; Gair, J.; Grover, K.; Graff, P.; Hanna, C.; Kalogera, V.; Mandel, I.; O'Shaughnessy, R.; Pitkin, M.; Price, L.; Raymond, V.; Röver, C.; Singer, L.; van der Sluys, M.; Smith, R. J. E.; Vecchio, A.; Veitch, J.; Vitale, S.

2014-04-01

The problem of reconstructing the sky position of compact binary coalescences detected via gravitational waves is a central one for future observations with the ground-based network of gravitational-wave laser interferometers, such as Advanced LIGO and Advanced Virgo. Different techniques for sky localization have been independently developed. They can be divided in two broad categories: fully coherent Bayesian techniques, which are high latency and aimed at in-depth studies of all the parameters of a source, including sky position, and "triangulation-based" techniques, which exploit the data products from the search stage of the analysis to provide an almost real-time approximation of the posterior probability density function of the sky location of a detection candidate. These techniques have previously been applied to data collected during the last science runs of gravitational-wave detectors operating in the so-called initial configuration. Here, we develop and analyze methods for assessing the self consistency of parameter estimation methods and carrying out fair comparisons between different algorithms, addressing issues of efficiency and optimality. These methods are general, and can be applied to parameter estimation problems other than sky localization. We apply these methods to two existing sky localization techniques representing the two above-mentioned categories, using a set of simulated inspiral-only signals from compact binary systems with a total mass of ≤20M⊙ and nonspinning components. We compare the relative advantages and costs of the two techniques and show that sky location uncertainties are on average a factor ≈20 smaller for fully coherent techniques than for the specific variant of the triangulation-based technique used during the last science runs, at the expense of a factor ≈1000 longer processing time.

Storytelling with an Audience in the Live Planetarium Program Starball

NASA Astrophysics Data System (ADS)

Kaufmann, J.

2013-04-01

Starball was conceived as a means of connecting planetarium audiences to the night sky in an imaginative, interactive way. Developed at the Smith Planetarium at Pacific Science Center in Seattle, Starball challenges each live audience to forget the “official” constellations and create original ones based on their own experiences and dreams. This paper details the philosophy behind the show and the specific planetarium and theater methods the performers employ to create an environment where such active participation is possible.

WorldWide Telescope and Google Sky: New Technologies to Engage Students and the Public

NASA Astrophysics Data System (ADS)

Landsberg, R. H.; Subbarao, M. U.; Dettloff, L.

2010-08-01

New, visually rich, astronomical software environments coupled with large web-accessible data sets hold the promise of new and exciting ways to teach, collaborate, and explore the universe. These freeware tools provide contextual views of astronomical objects, real time access to multi-wavelength sky surveys, and, most importantly, the ability to incorporate new data and to produce user created content. This interactive panel examined the capabilities of Google Sky and WorldWide Telescope, and explored case studies of how these tools have been used to create compelling and participatory educational experiences in both formal (i.e., K-12 and undergraduate non-science majors classrooms), and informal (e.g., museum) settings. The overall goal of this session was to stimulate a discussion about future uses of these technologies. Substantial time was allotted for participants to create conceptual designs of learning experiences for use at their home institutions, with feedback provided by the panel members. Activities included technical discussions (e.g., mechanisms for incorporating new data and dissemination tools), exercises in narrative preparation, and a brainstorming session to identify potential future uses of these technologies.

Experience-related reorganization of giant synapses in the lateral complex: Potential role in plasticity of the sky-compass pathway in the desert ant Cataglyphis fortis.

PubMed

Schmitt, Franziska; Stieb, Sara Mae; Wehner, Rüdiger; Rössler, Wolfgang

2016-04-01

Cataglyphis desert ants undergo an age-related polyethism from interior workers to relatively short-lived foragers with remarkable visual navigation capabilities, predominantly achieved by path integration using a polarized skylight-based sun compass and a stride-integrating odometer. Behavioral and physiological experiments revealed that the polarization (POL) pattern is processed via specialized UV-photoreceptors in the dorsal rim area of the compound eye and POL sensitive optic lobe neurons. Further information about the neuronal substrate for processing of POL information in the ant brain has remained elusive. This work focuses on the lateral complex (LX), known as an important relay station in the insect sky-compass pathway. Neuroanatomical results in Cataglyphis fortis show that LX giant synapses (GS) connect large presynaptic terminals from anterior optic tubercle neurons with postsynaptic GABAergic profiles of tangential neurons innervating the ellipsoid body of the central complex. At the ultrastructural level, the cup-shaped presynaptic structures comprise many active zones contacting numerous small postsynaptic profiles. Three-dimensional quantification demonstrated a significantly higher number of GS (∼ 13%) in foragers compared with interior workers. Light exposure, as opposed to age, was necessary and sufficient to trigger a similar increase in GS numbers. Furthermore, the increase in GS numbers was sensitive to the exclusion of UV light. As previous experiments have demonstrated the importance of the UV spectrum for sky-compass navigation in Cataglyphis, we conclude that plasticity in LX GS may reflect processes involved in the initial calibration of sky-compass neuronal circuits during orientation walks preceding active foraging. © 2015 Wiley Periodicals, Inc.

Dark Skies are a Universal Resource: IYA Programs on Dark Skies Awareness

NASA Astrophysics Data System (ADS)

Walker, Constance E.; Bueter, C.; Pompea, S. M.; Berglund, K.; Mann, T.; Gay, P.; Crelin, B.; Collins, D.; Sparks, R.

2008-05-01

The loss of a dark night sky as a natural resource is a growing concern. It impacts not only astronomical research, but also health, ecology, safety, economics and energy conservation. Because of its relevance, "Dark Skies” is a theme of the US Node for the International Year of Astronomy (IYA). Its goal is to raise public awareness of the impact of artificial lighting on local environments by getting people involved in a variety of dark skies-related programs. To reach this goal, the ASP session will immerse participants in hands-on, minds-on activities, events and resources on dark skies awareness. These include a planetarium show on DVD, podcasting, social networking, a digital photography contest, The Great Switch Out, Earth Hour, National Dark Skies Week, a traveling exhibit, a 6-minute video tutorial, Dark Skies Teaching Sites, Astronomy Nights in the (National) Parks, Sidewalk Astronomy Nights, and unaided-eye and digital-meter star counting programs like GLOBE at Night. The ASP "Dark Skies” session is offered to provide IYA dark skies-related programs to a variety of attendees. Participants include professional or amateur astronomers, education and public outreach professionals, science center/museum/planetarium staff and educators who want to lead activities involving dark skies awareness in conjunction with IYA. During the session, each participant will be given a package of educational materials on the various dark skies programs. We will provide the "know-how” and the means for session attendees to become community leaders in promoting these dark skies programs as public events at their home institutions during IYA. Participants will be able to jump-start their education programs through the use of well-developed instructional materials and kits sent later if they commit to leading IYA dark skies activities. For more information about the IYA Dark Skies theme, visit http://astronomy2009.us/darkskies/.

Studying the Sky/Planets Can Drown You in Images: Machine Learning Solutions at JPL/Caltech

NASA Technical Reports Server (NTRS)

Fayyad, U. M.

1995-01-01

JPL is working to develop a domain-independent system capable of small-scale object recognition in large image databases for science analysis. Two applications discussed are the cataloging of three billion sky objects in the Sky Image Cataloging and Analysis Tool (SKICAT) and the detection of possibly one million small volcanoes visible in the Magellan synthetic aperture radar images of Venus (JPL Adaptive Recognition Tool, JARTool).

X-ray Lobster Eye all-sky monitor for rocket experiment

NASA Astrophysics Data System (ADS)

Dániel, V.; Inneman, A.; Pína, L.; Zadražil, V.; Báča, T.; Stehlíková, V.; Nentvich, O.; Urban, M.; Maršíková, V.; McEntaffer, R.; Tutt, J.; Schulz, T.

2017-05-01

This paper presents a Lobster Eye (LE) X-ray telescope developed for the Water Recovery X-ray Rocket (WRX-R) experiment. The primary payload of the rocket experiment is a soft X-ray spectroscope developed by the Pennsylvania State University (PSU), USA. The Czech team participates by hard LE X-ray telescope as a secondary payload. The astrophysical objective of the rocket experiment is the Vela Supernova of size about 8deg x 8deg. In the center of the nebula is a neutron star with a strong magnetic field, roughly the mass of the Sun and a diameter of about 20 kilometers forming the Vela pulsar. The primary objective of WRX-R is the spectral measurement of the outer part of the nebula in soft X-ray and FOV of 3.25deg x 3.25deg. The secondary objective (hard LE X-ray telescope) is the Vela neutron star observation. The hard LE telescope consists of two X-ray telescopes with the Timepix detector. First telescope uses 2D LE Schmidt optics (2DLE- REX) with focal length over 1m and 4 Timepix detectors (2x2 matrix). The telescope FOV is 1.5deg x 1.5deg with spectral range from 3keV to 60keV. The second telescope uses 1D LE Schmidt optics (1D-LE-REX) with focal length of 25 cm and one Timepix detector. The telescope is made as a wide field with FOV 4.5deg x 3.5deg and spectral range from 3keV to 40keV. The rocket experiment serves as a technology demonstration mission for the payloads. The LE X-ray telescopes can be in the future used as all-sky monitor/surveyor. The astrophysical observation can cover the hard X-ray observation of astrophysical sources in time-domain, the GRBs surveying or the exploration of the gravitational wave sources.

Origins of the ancient constellations: I. The Mesopotamian traditions

NASA Astrophysics Data System (ADS)

Rogers, J. H.

1998-02-01

In the sky-map of ancient Babylon, constellations had two different roles, and thus developed into two overlapping traditions. One set of constellations represented the gods and their symbols; the other set represented rustic activities and provided a farming calendar. Many constellations were shared by the two traditions, but in some regions of sky there were alternative divine and rustic figures. These figures developed in stages from ~3200 BC to ~500 BC. Of the divine set, the most important (although the last to be finalised) were the twelve zodiacal signs, plus several associated animals (the serpent, crow, eagle, and fish), which were all transmitted to the classical Greek sky-map that we still use today. Conversely, the rustic constellations of workers and tools and animals were not transmitted to the West. However, a few of them may have survived in Bedouin Arab sky-maps of the first millennium AD.

Providing Diurnal Sky Cover Data at ARM Sites

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

Klebe, Dimitri I.

2015-03-06

The Solmirus Corporation was awarded two-year funding to perform a comprehensive data analysis of observations made during Solmirus’ 2009 field campaign (conducted from May 21 to July 27, 2009 at the ARM SGP site) using their All Sky Infrared Visible Analyzer (ASIVA) instrument. The objective was to develop a suite of cloud property data products for the ASIVA instrument that could be implemented in real time and tailored for cloud modelers. This final report describes Solmirus’ research and findings enabled by this grant. The primary objective of this award was to develop a diurnal sky cover (SC) data product utilizingmore » the ASIVA’s infrared (IR) radiometrically-calibrated data and is described in detail. Other data products discussed in this report include the sky cover derived from ASIVA’s visible channel and precipitable water vapor, cloud temperature (both brightness and color), and cloud height inferred from ASIVA’s IR channels.« less

Spectrophotometric experiment on the Verera-11 and Venera-12 descent vehicles: Some results of the analysis of the spectrum of the daytime sky of Venus

NASA Technical Reports Server (NTRS)

Moroz, V. I.; Moshkin, B. Y.; Ekonomov, A. P.; Sanko, N. F.; Parfentev, N. A.; Golovin, Y. M.

1979-01-01

The spectra of the daytime sky of Venus were recorded on the Venera-11 and Venera-12 descent vehicles at various altitudes above the planet's surface, within the interval of 4500 to 12,000 Angstroms. The angular distribution of the brightness of the scattered radiation was recorded and the ratio of water and carbon dioxide were studied, with respect to the cloud cover boundaries.

draco: Analysis and simulation of drift scan radio data

NASA Astrophysics Data System (ADS)

Shaw, J. Richard

2017-12-01

draco analyzes transit radio data with the m-mode formalism. It is telescope agnostic, and is used as part of the analysis and simulation pipeline for the CHIME (Canadian Hydrogen Intensity Mapping Experiment) telescope. It can simulate time stream data from maps of the sky (using the m-mode formalism) and add gain fluctuations and correctly correlated instrumental noise (i.e. Wishart distributed). Further, it can perform various cuts on the data and make maps of the sky from data using the m-mode formalism.

News from Online: A Spectrum of Color

NASA Astrophysics Data System (ADS)

Sweeney Judd, Carolyn

1999-06-01

Thomas Chasteen's site ( http://www.shsu.edu/~chm_tgc/sounds/sound.html) shows how to separate colors using a tuneable monochromator. This graphic comes from his monochromator animation ( http://www.shsu.edu/~chemistry/monochromator/mono.gif). Science Media's site ( http://www.scimedia.com/index.html#scimedia) includes spectroscopy tutorials by Brian Tissue. This graphic can be found at http://www.scimedia.com/chem-ed/light/graphics/em-rad.gif (©1998 B. M. Tissue, www.scimedia.com). All the colors in the rainbow! Now that is a good place to start. Go to About Rainbows ( http://www.unidata.ucar.edu/staff/blynds/rnbw.html), a tutorial from astronomer Beverly Lynds, working with the University Corporation for Atmospheric Research. The tutorial begins with a historical perspective, complete with a sketch by René Descartes in 1637. The bibliography makes this tutorial a good starting point for color exploration. About Rainbows brings you questions to explorefor example, "What happens when you look at a rainbow through dark glasses?" Try the links to these other sites. Project SkyMath: Making Mathematical Connections ( http://www.unidata.ucar.edu/staff/blynds/Skymath.html) is especially for the middle school student. Reproducible masters of these teaching modules can be printed in English and Spanish. From Project SkyMath, you can go to Blue-Skies, a user-friendly graphical interface from The Weather Underground at the University of Michigan ( http://groundhog.sprl.umich.edu/BS.html). And speaking of blue skies, look at a great site, Why is the Sky Blue at http://acept.la.asu.edu/PiN/act/sky/sky.shtml. This is a super site from the Arizona Collaborative for Excellence in the Preparation of Teachers, by the Department of Physics and Astronomy at Arizona State University. If you go to Patterns in Nature: Light and Optics at http://acept.la.asu.edu/PiN/act/activities.shtml, plan to spend some time, for it is wonderful. Another link from the About Rainbows tutorial goes to an experiment that is suitable for older students, Circles of Light--The Mathematics of Rainbows at http://www.geom.umn.edu/education/calc-init/rainbow/. Frederick J. Wicklin and Paul Edelman of the University of Minnesota note that this comprehensive lab is based on a module developed by Steven Janke. Go back to About Rainbows to link to a Java applet, allowing you to change the incident angle and color of light striking a water droplet. This great teaching device is from Fu-Kwun Hwang of the National Taiwan Normal University at http://science.kongju.ac.kr/phys/shin/experiment/ntnujava /Rainbow/rainbow.html. And while you are here in this site (choose English or Chinese), look at the more than 30 Java applets created by F.-K. Hwang at http://science.kongju.ac.kr/phys/shin/experiment/ntnujava/index.html. The interactive applet on Shadow/Image and Color is great fun, (http://science.kongju.ac.kr/phys/shin/experiment/ntnujava/shadow /shadow.html). From mixing colors, we can go to Thomas Chasteen's fine work at http://www.shsu.edu/~chm_tgc/sounds/sound.html for an animation (and movie also) of how to separate colors using a tuneable monochromator ( http://www.shsu.edu/~chemistry/monochromator/mono.gif). This colorful graphic, showing incoming parallel white light, is clipped from that monochromator animation. While you are here at this site at Sam Houston State University, look at the other great animations and movies, including a movie showing solution-phase chemiluminescence at http://www.shsu.edu/~chm_tgc/chemilumdir/movie.html. So now that we have explored the breaking down of light into its component colors, we need to also look at another process--polarizing light. Let's go to Science Media's comprehensive site ( http://www.scimedia.com/index.html#scimedia) to examine polarized light ( http://www.scimedia.com/chem-ed/spec/molec/polarim.htm). Of course, most sunglasses polarize light--bringing us back to the question of the rainbow again. Explore here for a while--appreciate the beautiful visible electromagnetic spectrum at http://www.scimedia.com/chem-ed/light/graphics/em-visib.jpg. Great spectroscopy tutorials from Brian Tissue of the Virginia Polytechnic Institute and State University are found at Science Media's site. One of my favorite graphics ( http://www.scimedia.com/chem-ed/light/graphics/em-rad.gif) reminds us of why light is electromagnetic radiation. But how to we actually see color? Go to the Access Excellence Classic Collection sponsored by Genentech, Inc. (http://www.gene.com/ae/AE/AEC/CC/). From here, go to How We See: The First Steps of Human Vision at http://www.gene.com/ae/AE/AEC/CC/vision_background.html. Here are good graphics and explanations of the roles of rod and cone cells, and lots more! And marvel a little the next time you see a rainbow. World Wide Web Addresses About Rainbows http://www.unidata.ucar.edu/staff/blynds/rnbw.html Project SkyMath: Making Mathematical Connections http://www.unidata.ucar.edu/staff/blynds/Skymath.html The Weather Underground at the University of Michigan--Blue- Skies http://groundhog.sprl.umich.edu/BS.html Why is the Sky Blue http://acept.la.asu.edu/PiN/act/sky/sky.shtml Patterns in NatureLight and Optics Activities http://acept.la.asu.edu/PiN/act/activities.shtml Circles of Lightthe Mathematics of Rainbows http://www.geom.umn.edu/education/calc-init/rainbow/ The Physics of a Rainbow http://science.kongju.ac.kr/phys/shin/experiment/ntnujava /Rainbow/rainbow.html The NTNU Virtual Physics Laboratory http://science.kongju.ac.kr/phys/shin/experiment/ntnujava /index.html Shadow/Image and Color http://science.kongju.ac.kr/phys/shin/experiment/ntnujava/shadow/shadow.html Thomas Chasteen's Chemistry-Based QuickTime Movies, Animations, and Streaming Audio http://www.shsu.edu/~chm_tgc/sounds/sound.html Tuneable Monochromator http://www.shsu.edu/~chemistry/monochromator/mono.gif The Chemiluminescence Home Page http://www.shsu.edu/~chm_tgc/chemilumdir/movie.html Science Hypermedia Home Page http://www.scimedia.com/index.html#scimedia Polarimetry http://www.scimedia.com/chem-ed/spec/molec/polarim.htm The Visible Spectrum http://www.scimedia.com/chem-ed/light/graphics/em-visib.jpg Propagation Direction of Electromagnetic Radiation http://www.scimedia.com/chem-ed/light/graphics/em-rad.gif Access Excellence Classic Collection http://www.gene.com/ae/AE/AEC/CC/ How We SeeThe First Steps of Human Vision http://www.gene.com/ae/AE/AEC/CC/vision_background.html access date for all sites: April 1999

Host model uncertainties in aerosol radiative forcing estimates: results from the AeroCom Prescribed intercomparison study

NASA Astrophysics Data System (ADS)

Stier, P.; Schutgens, N. A. J.; Bellouin, N.; Bian, H.; Boucher, O.; Chin, M.; Ghan, S.; Huneeus, N.; Kinne, S.; Lin, G.; Ma, X.; Myhre, G.; Penner, J. E.; Randles, C. A.; Samset, B.; Schulz, M.; Takemura, T.; Yu, F.; Yu, H.; Zhou, C.

2013-03-01

Simulated multi-model "diversity" in aerosol direct radiative forcing estimates is often perceived as a measure of aerosol uncertainty. However, current models used for aerosol radiative forcing calculations vary considerably in model components relevant for forcing calculations and the associated "host-model uncertainties" are generally convoluted with the actual aerosol uncertainty. In this AeroCom Prescribed intercomparison study we systematically isolate and quantify host model uncertainties on aerosol forcing experiments through prescription of identical aerosol radiative properties in twelve participating models. Even with prescribed aerosol radiative properties, simulated clear-sky and all-sky aerosol radiative forcings show significant diversity. For a purely scattering case with globally constant optical depth of 0.2, the global-mean all-sky top-of-atmosphere radiative forcing is -4.47 Wm-2 and the inter-model standard deviation is 0.55 Wm-2, corresponding to a relative standard deviation of 12%. For a case with partially absorbing aerosol with an aerosol optical depth of 0.2 and single scattering albedo of 0.8, the forcing changes to 1.04 Wm-2, and the standard deviation increases to 1.01 W-2, corresponding to a significant relative standard deviation of 97%. However, the top-of-atmosphere forcing variability owing to absorption (subtracting the scattering case from the case with scattering and absorption) is low, with absolute (relative) standard deviations of 0.45 Wm-2 (8%) clear-sky and 0.62 Wm-2 (11%) all-sky. Scaling the forcing standard deviation for a purely scattering case to match the sulfate radiative forcing in the AeroCom Direct Effect experiment demonstrates that host model uncertainties could explain about 36% of the overall sulfate forcing diversity of 0.11 Wm-2 in the AeroCom Direct Radiative Effect experiment. Host model errors in aerosol radiative forcing are largest in regions of uncertain host model components, such as stratocumulus cloud decks or areas with poorly constrained surface albedos, such as sea ice. Our results demonstrate that host model uncertainties are an important component of aerosol forcing uncertainty that require further attention.

A comparison of the Stratospheric Aerosol and Gas Experiment II tropospheric water vapor to radiosonde measurements

NASA Technical Reports Server (NTRS)

Larsen, J. C.; Chiou, E. W.; Chu, W. P.; Mccormick, M. P.; Mcmaster, L. R.; Oltmans, S.; Rind, D.

1993-01-01

Results are presented of a comparison beteen observations of the upper-tropospheric water vapor data obtained from the Stratospheric Aerosol and Gas Experiment II (SAGE II) instrument and radiosonde observations for 1987 and radiosonde-based climatologies. Colocated SAGE II-radiosonde measurement pairs are compared individually and in a zonal mean sense. A straight comparison of monthly zonal means between SAGE II and radiosondes for 1987 and Global Atmospheric Statistics (1963-1973) indicates that the clear-sky SAGE II climatology is approximately half the level of clear/cloudy sky of both radiosonde climatologies. Annual zonal means calculated from the set of profile pairs again showed SAGE II to be significantly drier in many altitude bands.

Non-cardinal color perception across the retina: easy for orange, hard for burgundy and sky blue.

PubMed

Gunther, Karen L

2014-04-01

Cardinal color performance (reddish, greenish, bluish, yellowish, black, and white) has been shown to decline in peripheral viewing. What about non-cardinal color performance (e.g., orange, burgundy, and sky blue)? In visual search, performance on non-cardinal colors matched that of the cardinal colors in the (L-M)/(S-(L+M)) (isoluminant) color plane (Experiment 1, n=10, to 30°; Experiment 2, n=3, to 50°). However, performance in the (L-M)/(L+M) and (S-(L+M))/(L+M) color planes was worse for non-cardinal colors, at all eccentricities, even in the fovea. The implications that these results have for the existence of non-cardinal mechanisms in each color plane are discussed.

Data Analysis for the E and B EXperiment and Instrumentation Development for Cosmic Microwave Background Polarimetry

NASA Astrophysics Data System (ADS)

Araujo, Derek C.

The E and B EXperiment (EBEX) was a balloon-borne instrument designed to measure the polarization of the cosmic microwave background (CMB) while simultaneously characterizing Galactic dust emission. The instrument was based on a two-mirror ambient temperature Gregorian-Dragone telescope coupled with cooled refractive optics to a kilo-pixel array of transition edge sensor (TES) bolometeric detectors. To achieve sensitivity to both the CMB signal and Galactic foregrounds, EBEX observed in three signal bands centered on 150, 250, and 410 GHz. Polarimetry was achieved via a stationary wire-grid polarizer and a continuously rotating achromatic half-wave plate (HWP) based on a superconducting magnetic bearing (SMB). EBEX launched from McMurdo station, Antarctica on December 29, 2012 and collected 1.3 TB of data during 11 days of observation. This thesis is presented in two Parts. Part I reviews the data analysis we performed to transform the raw EBEX data into maps of temperature and polarization sky signals, with a particular focus on post-flight pointing reconstruction; time stream cleaning and map making; the generation of model sky maps of the expected signal for each of the three EBEX signal bands; removal of the HWP-synchronous signal from the detector time streams; and our attempts to identify, characterize, and correct for non-linear detector responsivity. In Part II we present recent developments in instrumentation for the next generation of CMB polarimeters. The developments we describe, including advances in lumped-element kinetic inductance detector (LEKID) technology and the development of a hollow-shaft SMB-based motor for use in HWP polarimetry, were motivated in part by the design for a prospective ground-based CMB polarimeter based in Greenland.

Applying machine learning classification techniques to automate sky object cataloguing

NASA Astrophysics Data System (ADS)

Fayyad, Usama M.; Doyle, Richard J.; Weir, W. Nick; Djorgovski, Stanislav

1993-08-01

We describe the application of an Artificial Intelligence machine learning techniques to the development of an automated tool for the reduction of a large scientific data set. The 2nd Mt. Palomar Northern Sky Survey is nearly completed. This survey provides comprehensive coverage of the northern celestial hemisphere in the form of photographic plates. The plates are being transformed into digitized images whose quality will probably not be surpassed in the next ten to twenty years. The images are expected to contain on the order of 107 galaxies and 108 stars. Astronomers wish to determine which of these sky objects belong to various classes of galaxies and stars. Unfortunately, the size of this data set precludes analysis in an exclusively manual fashion. Our approach is to develop a software system which integrates the functions of independently developed techniques for image processing and data classification. Digitized sky images are passed through image processing routines to identify sky objects and to extract a set of features for each object. These routines are used to help select a useful set of attributes for classifying sky objects. Then GID3 (Generalized ID3) and O-B Tree, two inductive learning techniques, learns classification decision trees from examples. These classifiers will then be applied to new data. These developmnent process is highly interactive, with astronomer input playing a vital role. Astronomers refine the feature set used to construct sky object descriptions, and evaluate the performance of the automated classification technique on new data. This paper gives an overview of the machine learning techniques with an emphasis on their general applicability, describes the details of our specific application, and reports the initial encouraging results. The results indicate that our machine learning approach is well-suited to the problem. The primary benefit of the approach is increased data reduction throughput. Another benefit is consistency of classification. The classification rules which are the product of the inductive learning techniques will form an objective, examinable basis for classifying sky objects. A final, not to be underestimated benefit is that astronomers will be freed from the tedium of an intensely visual task to pursue more challenging analysis and interpretation problems based on automatically catalogued data.

Success of sky-polarimetric Viking navigation: revealing the chance Viking sailors could reach Greenland from Norway

NASA Astrophysics Data System (ADS)

Száz, Dénes; Horváth, Gábor

2018-04-01

According to a famous hypothesis, Viking sailors could navigate along the latitude between Norway and Greenland by means of sky polarization in cloudy weather using a sun compass and sunstone crystals. Using data measured in earlier atmospheric optical and psychophysical experiments, here we determine the success rate of this sky-polarimetric Viking navigation. Simulating 1000 voyages between Norway and Greenland with varying cloudiness at summer solstice and spring equinox, we revealed the chance with which Viking sailors could reach Greenland under the varying weather conditions of a 3-week-long journey as a function of the navigation periodicity Δt if they analysed sky polarization with calcite, cordierite or tourmaline sunstones. Examples of voyage routes are also presented. Our results show that the sky-polarimetric navigation is surprisingly successful on both days of the spring equinox and summer solstice even under cloudy conditions if the navigator determined the north direction periodically at least once in every 3 h, independently of the type of sunstone used for the analysis of sky polarization. This explains why the Vikings could rule the Atlantic Ocean for 300 years and could reach North America without a magnetic compass. Our findings suggest that it is not only the navigation periodicity in itself that is important for higher navigation success rates, but also the distribution of times when the navigation procedure carried out is as symmetrical as possible with respect to the time point of real noon.

Success of sky-polarimetric Viking navigation: revealing the chance Viking sailors could reach Greenland from Norway.

PubMed

Száz, Dénes; Horváth, Gábor

2018-04-01

According to a famous hypothesis, Viking sailors could navigate along the latitude between Norway and Greenland by means of sky polarization in cloudy weather using a sun compass and sunstone crystals. Using data measured in earlier atmospheric optical and psychophysical experiments, here we determine the success rate of this sky-polarimetric Viking navigation. Simulating 1000 voyages between Norway and Greenland with varying cloudiness at summer solstice and spring equinox, we revealed the chance with which Viking sailors could reach Greenland under the varying weather conditions of a 3-week-long journey as a function of the navigation periodicity Δ t if they analysed sky polarization with calcite, cordierite or tourmaline sunstones. Examples of voyage routes are also presented. Our results show that the sky-polarimetric navigation is surprisingly successful on both days of the spring equinox and summer solstice even under cloudy conditions if the navigator determined the north direction periodically at least once in every 3 h, independently of the type of sunstone used for the analysis of sky polarization. This explains why the Vikings could rule the Atlantic Ocean for 300 years and could reach North America without a magnetic compass. Our findings suggest that it is not only the navigation periodicity in itself that is important for higher navigation success rates, but also the distribution of times when the navigation procedure carried out is as symmetrical as possible with respect to the time point of real noon.

Success of sky-polarimetric Viking navigation: revealing the chance Viking sailors could reach Greenland from Norway

PubMed Central

Száz, Dénes; Horváth, Gábor

2018-01-01

According to a famous hypothesis, Viking sailors could navigate along the latitude between Norway and Greenland by means of sky polarization in cloudy weather using a sun compass and sunstone crystals. Using data measured in earlier atmospheric optical and psychophysical experiments, here we determine the success rate of this sky-polarimetric Viking navigation. Simulating 1000 voyages between Norway and Greenland with varying cloudiness at summer solstice and spring equinox, we revealed the chance with which Viking sailors could reach Greenland under the varying weather conditions of a 3-week-long journey as a function of the navigation periodicity Δt if they analysed sky polarization with calcite, cordierite or tourmaline sunstones. Examples of voyage routes are also presented. Our results show that the sky-polarimetric navigation is surprisingly successful on both days of the spring equinox and summer solstice even under cloudy conditions if the navigator determined the north direction periodically at least once in every 3 h, independently of the type of sunstone used for the analysis of sky polarization. This explains why the Vikings could rule the Atlantic Ocean for 300 years and could reach North America without a magnetic compass. Our findings suggest that it is not only the navigation periodicity in itself that is important for higher navigation success rates, but also the distribution of times when the navigation procedure carried out is as symmetrical as possible with respect to the time point of real noon. PMID:29765673

Dark Skies Awareness Programs for the U.S. International Year of Astronomy

NASA Astrophysics Data System (ADS)

Walker, Constance E.; U. S. IYA Dark Skies Working Group

2009-01-01

The loss of a dark night sky as a natural resource is a growing concern. It impacts not only astronomical research, but also our ecology, health, safety, economics and energy conservation. For this reason, "Dark Skies are a Universal Resource” is one of seven primary themes of the U.S. International Year of Astronomy program in 2009. Its goal is to raise public awareness of the impact of artificial lighting on local environments by getting people involved in a variety of dark skies-related programs. To reach this goal, activities have been developed that: 1) Teach about dark skies using new technology (e.g., an activity-based planetarium show on DVD, podcasting, social networking, Second Life) 2) Provide thematic events on light pollution at star parties and observatory open houses (Dark Skies Discovery Sites, Astronomy Nights in the (National) Parks, Sidewalk Astronomy Nights) 3) Organize an event in the arts (e.g., a photography contest) 4) Involve citizen-scientists in unaided-eye and digital-meter star counting programs, as well as RFI monitoring (e.g., GLOBE at Night and Quiet Skies) and 5) Raise awareness about the link between light pollution and public health, economic issues, ecological consequences, energy conservation, safety and security (e.g., the Dark Skies Toolkit, Good Neighbor Lighting, Earth Hour, National Dark Skies Week, traveling exhibits and a 6-minute video tutorial). To deliver these programs, strategic networks have been established with astronomy clubs (ASP's Night Sky Network's astronomy clubs and the Astronomical League), science and nature centers (Astronomy from the Ground Up and the Association of Science and Technology), educational programs (Project ASTRO and GLOBE) and the International Dark-sky Association. The poster will describe the "know-how” and the means for people to become community advocates in promoting Dark Skies programs as public events at their home institutions. For more information, visit http://astronomy2009.us/darkskies/.

Examining Dense Data Usage near the Regions with Severe Storms in All-Sky Microwave Radiance Data Assimilation and Impacts on GEOS Hurricane Analyses

NASA Technical Reports Server (NTRS)

Kim, Min-Jeong; Jin, Jianjun; McCarty, Will; El Akkraoui, Amal; Todling, Ricardo; Gelaro, Ron

2018-01-01

Many numerical weather prediction (NWP) centers assimilate radiances affected by clouds and precipitation from microwave sensors, with the expectation that these data can provide critical constraints on meteorological parameters in dynamically sensitive regions to make significant impacts on forecast accuracy for precipitation. The Global Modeling and Assimilation Office (GMAO) at NASA Goddard Space Flight Center assimilates all-sky microwave radiance data from various microwave sensors such as all-sky GPM Microwave Imager (GMI) radiance in the Goddard Earth Observing System (GEOS) atmospheric data assimilation system (ADAS), which includes the GEOS atmospheric model, the Gridpoint Statistical Interpolation (GSI) atmospheric analysis system, and the Goddard Aerosol Assimilation System (GAAS). So far, most of NWP centers apply same large data thinning distances, that are used in clear-sky radiance data to avoid correlated observation errors, to all-sky microwave radiance data. For example, NASA GMAO is applying 145 km thinning distances for most of satellite radiance data including microwave radiance data in which all-sky approach is implemented. Even with these coarse observation data usage in all-sky assimilation approach, noticeable positive impacts from all-sky microwave data on hurricane track forecasts were identified in GEOS-5 system. The motivation of this study is based on the dynamic thinning distance method developed in our all-sky framework to use of denser data in cloudy and precipitating regions due to relatively small spatial correlations of observation errors. To investigate the benefits of all-sky microwave radiance on hurricane forecasts, several hurricane cases selected between 2016-2017 are examined. The dynamic thinning distance method is utilized in our all-sky approach to understand the sources and mechanisms to explain the benefits of all-sky microwave radiance data from various microwave radiance sensors like Advanced Microwave Sounder Unit (AMSU-A), Microwave Humidity Sounder (MHS), and GMI on GEOS-5 analyses and forecasts of various hurricanes.

Global Sky Model (GSM): A Model of Diffuse Galactic Radio Emission from 10 MHz to 100 GHz

NASA Astrophysics Data System (ADS)

de Oliveira-Costa, Angelica; Tegmark, Max; Gaensler, B. M.; Jonas, Justin; Landecker, T. L.; Reich, Patricia

2010-11-01

Understanding diffuse Galactic radio emission is interesting both in its own right and for minimizing foreground contamination of cosmological measurements. Cosmic Microwave Background experiments have focused on frequencies > 10 GHz, whereas 21 cm tomography of the high redshift universe will mainly focus on < 0.2 GHz, for which less is currently known about Galactic emission. Motivated by this, we present a global sky model derived from all publicly available total power large-area radio surveys, digitized with optical character recognition when necessary and compiled into a uniform format, as well as the new Villa Elisa data extending the 1.4 GHz map to the entire sky. We quantify statistical and systematic uncertainties in these surveys by comparing them with various global multi-frequency model fits. We find that a principal component based model with only three components can fit the 11 most accurate data sets (at 10, 22, 45 & 408 MHz and 1.4, 2.3, 23, 33, 41, 61, 94 GHz) to an accuracy around 1%-10% depending on frequency and sky region. The data compilation and software returning a predicted all-sky map at any frequency from 10 MHz to 100 GHz are publicly available at the link below.

The impact of modelling errors on interferometer calibration for 21 cm power spectra

NASA Astrophysics Data System (ADS)

Ewall-Wice, Aaron; Dillon, Joshua S.; Liu, Adrian; Hewitt, Jacqueline

2017-09-01

We study the impact of sky-based calibration errors from source mismodelling on 21 cm power spectrum measurements with an interferometer and propose a method for suppressing their effects. While emission from faint sources that are not accounted for in calibration catalogues is believed to be spectrally smooth, deviations of true visibilities from model visibilities are not, due to the inherent chromaticity of the interferometer's sky response (the 'wedge'). Thus, unmodelled foregrounds, below the confusion limit of many instruments, introduce frequency structure into gain solutions on the same line-of-sight scales on which we hope to observe the cosmological signal. We derive analytic expressions describing these errors using linearized approximations of the calibration equations and estimate the impact of this bias on measurements of the 21 cm power spectrum during the epoch of reionization. Given our current precision in primary beam and foreground modelling, this noise will significantly impact the sensitivity of existing experiments that rely on sky-based calibration. Our formalism describes the scaling of calibration with array and sky-model parameters and can be used to guide future instrument design and calibration strategy. We find that sky-based calibration that downweights long baselines can eliminate contamination in most of the region outside of the wedge with only a modest increase in instrumental noise.

Using cluster analysis and a classification and regression tree model to developed cover types in the Sky Islands of southeastern Arizona

Treesearch

Jose M. Iniguez; Joseph L. Ganey; Peter J. Daughtery; John D. Bailey

2005-01-01

The objective of this study was to develop a rule based cover type classification system for the forest and woodland vegetation in the Sky Islands of southeastern Arizona. In order to develop such a system we qualitatively and quantitatively compared a hierarchical (Ward’s) and a non-hierarchical (k-means) clustering method. Ecologically, unique groups represented by...

Using cluster analysis and a classification and regression tree model to developed cover types in the Sky Islands of southeastern Arizona [Abstract

Treesearch

Jose M. Iniguez; Joseph L. Ganey; Peter J. Daugherty; John D. Bailey

2005-01-01

The objective of this study was to develop a rule based cover type classification system for the forest and woodland vegetation in the Sky Islands of southeastern Arizona. In order to develop such system we qualitatively and quantitatively compared a hierarchical (Ward’s) and a non-hierarchical (k-means) clustering method. Ecologically, unique groups and plots...

The Thirty Gigahertz Instrument Receiver for the QUIJOTE Experiment: Preliminary Polarization Measurements and Systematic-Error Analysis.

PubMed

Casas, Francisco J; Ortiz, David; Villa, Enrique; Cano, Juan L; Cagigas, Jaime; Pérez, Ana R; Aja, Beatriz; Terán, J Vicente; de la Fuente, Luisa; Artal, Eduardo; Hoyland, Roger; Génova-Santos, Ricardo

2015-08-05

This paper presents preliminary polarization measurements and systematic-error characterization of the Thirty Gigahertz Instrument receiver developed for the QUIJOTE experiment. The instrument has been designed to measure the polarization of Cosmic Microwave Background radiation from the sky, obtaining the Q, U, and I Stokes parameters of the incoming signal simultaneously. Two kinds of linearly polarized input signals have been used as excitations in the polarimeter measurement tests in the laboratory; these show consistent results in terms of the Stokes parameters obtained. A measurement-based systematic-error characterization technique has been used in order to determine the possible sources of instrumental errors and to assist in the polarimeter calibration process.

Estimation of clear-sky insolation using satellite and ground meteorological data

NASA Technical Reports Server (NTRS)

Staylor, W. F.; Darnell, W. L.; Gupta, S. K.

1983-01-01

Ground based pyranometer measurements were combined with meteorological data from the Tiros N satellite in order to estimate clear-sky insolations at five U.S. sites for five weeks during the spring of 1979. The estimates were used to develop a semi-empirical model of clear-sky insolation for the interpretation of input data from the Tiros Operational Vertical Sounder (TOVS). Using only satellite data, the estimated standard errors in the model were about 2 percent. The introduction of ground based data reduced errors to around 1 percent. It is shown that although the errors in the model were reduced by only 1 percent, TOVS data products are still adequate for estimating clear-sky insolation.

The GalileoMobile Project

NASA Astrophysics Data System (ADS)

Del Pilar Becerra, A.&ída; Bhatt, Megha; Kobel, Philippe

2012-07-01

GalileoMobile is a traveling science education project by an international team of PhD students and recent graduates (partnering with the Universe Awareness program) that brings astronomy to young people in remote regions of developing countries. Our primary project goals are: (1) to stimulate students' curiosity and interest in learning, (2) to exchange different visions of the cosmos and cultures, and (3) to inspire a feeling of unity "under the same sky" between people from different parts of the world. In 2009, GalileoMobile traveled to 30 schools in Chile, Bolivia and Peru, bringing hands-on activities and Galileoscopes; the team also produced a documentary movie to share the experiences and culture with the world. In 2012, GalileoMobile plans an expedition to India from the 2nd to the 13th of July in villages between Bangalore and Mysore. We will again bring hands-on astronomy activities and telescopes to the schools, and share our experiences with the world via internet resources. GalileoMobile is also collaborating with the Galileo Teacher Training Program to provide workshops for local teachers, to encourage continuation of astronomy education beyond our visit. In this way, we expect to spark sustainable interest in astronomy in remote areas that have little access to science outreach, and to share the culture of these areas with the world -- "under the same sky."

Basic Color Terms (BCTs) and Categories (BCCs) in Three Dialects of the Spanish Language: Interaction Between Cultural and Universal Factors

PubMed Central

Lillo, Julio; González-Perilli, Fernando; Prado-León, Lilia; Melnikova, Anna; Álvaro, Leticia; Collado, José A.; Moreira, Humberto

2018-01-01

Two experiments were performed to identify and compare the Basic Color Terms (BCTs) and the Basic Color Categories (BCCs) included in three dialects (Castilian, Mexican, and Uruguayan) of the Spanish language. Monolexemic Elicited lists were used in the first experiment to identify the BCTs of each dialect. Eleven BCTs appeared for the Spanish and the Mexican, and twelve did so for the Uruguayan. The six primary BCTs (rojo “red,” verde “green,” amarillo “yellow,” azul “blue,” negro “black,” and blanco “white”) appeared in the three dialects. This occurred for only three derived BCTs (gris “gray,” naranja “orange,” and rosa “pink”) but not for the other five derived BCTs (celeste “sky blue,” marrón “brown,” café “brown,” morado “purple,” and violeta “purple”). Color transitions were used in the second experiment for two different tasks. Extremes naming task was used to determine the relation between two different dialects' BCTs: equality, equivalence or difference. The results provided the first evidence for marrón “brown” and café “brown” being equivalent terms for the same BCC (brown in English) as is the case of morado “purple” and violeta “purple.” Uruguayan celeste “sky blue” had no equivalent BCT in the other two dialects. Boundary delimitation task required the selection of the color in the boundary between two categories. The task was used to reasonably estimate the volume occupied by each BCC in the color space considering its chromatic area and lightness range. Excluding sky blue (celeste “sky blue”) and blue (azul “blue”), the other BCCs color volumes were similar across the three dialects. Uruguayan sky blue and blue volumes conjointly occupied the portion of the color space corresponding to the Castilian and Mexican blue BCC. The fact that the BCT celeste “sky blue” only appeared in Uruguayan very probably derived from specific cultural factors (the use of the color in the flags and the arrival of an important number of Italian immigrants). Nevertheless, these cultural factors seem to nurture from a perceptive structuring of the color space, which nature is universal, as the boundaries of this category can be delimited from the responses of Spanish and Mexican participants. PMID:29867702

Using All-Sky Imaging to Improve Telescope Scheduling (Abstract)

NASA Astrophysics Data System (ADS)

Cole, G. M.

2017-12-01

(Abstract only) Automated scheduling makes it possible for a small telescope to observe a large number of targets in a single night. But when used in areas which have less-than-perfect sky conditions such automation can lead to large numbers of observations of clouds and haze. This paper describes the development of a "sky-aware" telescope automation system that integrates the data flow from an SBIG AllSky340c camera with an enhanced dispatch scheduler to make optimum use of the available observing conditions for two highly instrumented backyard telescopes. Using the minute-by-minute time series image stream and a self-maintained reference database, the software maintains a file of sky brightness, transparency, stability, and forecasted visibility at several hundred grid positions. The scheduling software uses this information in real time to exclude targets obscured by clouds and select the best observing task, taking into account the requirements and limits of each instrument.

The use of a laser ceilometer for sky condition determination

NASA Astrophysics Data System (ADS)

Nadolski, Vickie L.; Bradley, James T.

The use of a laser ceilometer for determining sky condition is presented, with emphasis on the operation of the ceilometer, the sky-condition-reporting algorithm, and how the laser ceilometer and the sky-condition algorithm are used to give a report suitable for aircraft operations and meteorological application. The sampling and processing features of the Vaisala ceilometer produced a detailed and accurate cloud base 'signature' by taking 254 measurement samples of the energy scattered back from a single laser pulse as the pulse traveled from the surface to 12,000 ft. The transmit time from the projection of the laser pulse to its backscattering from a cloud element and subsequent return to a collocated receiver is measured and a cloud height element computed. Attention is given to the development of a vertical visibility concept and of a vertical-visibility algorithm, as well as the strengths and limitations of the sky condition report.

Whole Sky Imager Characterization of Sky Obscuration by Clouds for the Starfire Optical Range

DTIC Science & Technology

2010-01-11

9.3 Further Algorithm Development and Evaluation 58 9.4 Analysis of the Data Base 58 10.0 DISCUSSION OF CONTRACT REQUIREMENTS 59 10.1...clouds, Site 5 Feb 14 2008 0900 28 21 Transmittance map, Moonlight , clear sky, Site 5 Feb 3 2008 0700 28 22 Transmittance map, Moonlight , thin...clouds, Site 5 Feb 8 2008 1200 29 23 Transmittance map, Moonlight , broken clouds, Site 5 Feb 2 2008 0800 29 24 Cloud Algorithm Results, Moonlight

SkyQuery - A Prototype Distributed Query and Cross-Matching Web Service for the Virtual Observatory

NASA Astrophysics Data System (ADS)

Thakar, A. R.; Budavari, T.; Malik, T.; Szalay, A. S.; Fekete, G.; Nieto-Santisteban, M.; Haridas, V.; Gray, J.

2002-12-01

We have developed a prototype distributed query and cross-matching service for the VO community, called SkyQuery, which is implemented with hierarchichal Web Services. SkyQuery enables astronomers to run combined queries on existing distributed heterogeneous astronomy archives. SkyQuery provides a simple, user-friendly interface to run distributed queries over the federation of registered astronomical archives in the VO. The SkyQuery client connects to the portal Web Service, which farms the query out to the individual archives, which are also Web Services called SkyNodes. The cross-matching algorithm is run recursively on each SkyNode. Each archive is a relational DBMS with a HTM index for fast spatial lookups. The results of the distributed query are returned as an XML DataSet that is automatically rendered by the client. SkyQuery also returns the image cutout corresponding to the query result. SkyQuery finds not only matches between the various catalogs, but also dropouts - objects that exist in some of the catalogs but not in others. This is often as important as finding matches. We demonstrate the utility of SkyQuery with a brown-dwarf search between SDSS and 2MASS, and a search for radio-quiet quasars in SDSS, 2MASS and FIRST. The importance of a service like SkyQuery for the worldwide astronomical community cannot be overstated: data on the same objects in various archives is mapped in different wavelength ranges and looks very different due to different errors, instrument sensitivities and other peculiarities of each archive. Our cross-matching algorithm preforms a fuzzy spatial join across multiple catalogs. This type of cross-matching is currently often done by eye, one object at a time. A static cross-identification table for a set of archives would become obsolete by the time it was built - the exponential growth of astronomical data means that a dynamic cross-identification mechanism like SkyQuery is the only viable option. SkyQuery was funded by a grant from the NASA AISR program.

A model of the 8-25 micron point source infrared sky

NASA Technical Reports Server (NTRS)

Wainscoat, Richard J.; Cohen, Martin; Volk, Kevin; Walker, Helen J.; Schwartz, Deborah E.

1992-01-01

We present a detailed model for the IR point-source sky that comprises geometrically and physically realistic representations of the Galactic disk, bulge, stellar halo, spiral arms (including the 'local arm'), molecular ring, and the extragalactic sky. We represent each of the distinct Galactic components by up to 87 types of Galactic source, each fully characterized by scale heights, space densities, and absolute magnitudes at BVJHK, 12, and 25 microns. The model is guided by a parallel Monte Carlo simulation of the Galaxy at 12 microns. The content of our Galactic source table constitutes a good match to the 12 micron luminosity function in the simulation, as well as to the luminosity functions at V and K. We are able to produce differential and cumulative IR source counts for any bandpass lying fully within the IRAS Low-Resolution Spectrometer's range (7.7-22.7 microns as well as for the IRAS 12 and 25 micron bands. These source counts match the IRAS observations well. The model can be used to predict the character of the point source sky expected for observations from IR space experiments.

Advertising Citizen Science: A Trailer for the Citizen Sky Project

NASA Astrophysics Data System (ADS)

Wyatt, Ryan; Price, A.

2012-01-01

Citizen Sky is a multi-year, NSF funded citizen science project involving the bright and mysterious variable star epsilon Aurigae. The project was conceived by the IYA 2009 working group on Research Experiences for Students, Teachers, and Citizen-Scientists. Citizen Sky goes beyond simple observing to include a major data analysis component, introducing participants to the full scientific process from background research to paper writing for a peer-reviewed journal. As a means of generating interest in the project, the California Academy of Sciences produced a six-minute "trailer” formatted for both traditional and fulldome planetariums as well as HD and web applications. This talk will review the production process for the trailer as well as the methods of distribution via planetariums, social media, and other venues_along with an update on the Citizen Sky Project as a whole. We will show how to use a small, professionally-produced planetarium trailer to help spread word on a citizen science project. We will also show preliminary results on a study about how participation level/type in the project affects science learning.

Correlated noise in the COBE DMR sky maps

NASA Technical Reports Server (NTRS)

Lineweaver, C. H.; Smoot, G. F.; Bennett, C. L.; Wright, E. L.; Tenorio, L.; Kogut, A.; Keegstra, P. B.; Hinshaw, G.; Banday, A. J.

1994-01-01

The Cosmic Background Explorer Satellite Differential Radiometer (COBE DMR) sky maps contain low-level correlated noise. We obtain estimates of the amplitude and pattern of the correlated noise from three techniques: angular averages of the covariance matrix, Monte Carlo simulations of two-point correlation functions and direct analysis of the DMR maps. The results from the three methods are mutually consistent. The noise covariance matrix of a DMR sky maps is diagonal to an accuracy of better than 1%. For a given sky pixel, the dominant noise covariance occure with the ring of pixels at an angular separation of 60 deg due to the 60 deg separation of the DMR horns. The mean covariance at 60 deg is 0.45%((sup +0.18)(sub -0.14)) of the mean variance. Additionally, the variance in a given pixel is 0.7% greater than would be expected from a single beam experiment with the same noise properties. Autocorrelation functions suffer from a approximately 1.5 sigma positive bias at 60 deg while cross-correlations have no bias. Published COBE DMR results are not significantly affected by correlated noise.

Analysis of photosynthetically active radiation under various sky conditions in Wuhan, Central China.

PubMed

Wang, Lunche; Gong, Wei; Lin, Aiwen; Hu, Bo

2014-10-01

Observations of photosynthetically active radiation (PAR) and global solar radiation (G) at Wuhan, Central China during 2005-2012 were first reported to investigate PAR variability at different time scales and its PAR fraction (F(p)) under different sky conditions. Both G irradiances (I(g)) and PAR irradiances (I(p)) showed similar seasonal features that peaked in values at noon during summer and reached their lower values in winter. F(p) reached higher values during either sunrise or sunset; lower values of F p appeared at local noon because of the absorption effects of water vapor and clouds on long-wave radiation. There was an inverse relationship between clearness index (K(t)) and F(p); the maximum I(p) decreased by 22.3 % (39.7 %) when sky conditions changed from overcast to cloudless in summer (winter); solar radiation was more affected by cloudiness than the seasonal variation in cloudy skies when compared with that in clear skies. The maximum daily PAR irradiation (R(p)) was 11.89 MJ m⁻² day⁻¹ with an annual average of 4.85 MJ m⁻² day⁻¹. F p was in the range of 29-61.5 % with annual daily average value being about 42 %. Meanwhile, hourly, daily, and monthly relationships between R p and G irradiation (R g) under different sky conditions were investigated. It was discovered that cloudy skies were the dominated sky condition in this region. Finally, a clear-sky PAR model was developed by analyzing the dependence of PAR irradiances on optical air mass under various sky conditions for the whole study period in Central China, which will lay foundations for ecological process study in the near future.

BlueSky Cloud - rapid infrastructure capacity using Amazon's Cloud for wildfire emergency response

NASA Astrophysics Data System (ADS)

Haderman, M.; Larkin, N. K.; Beach, M.; Cavallaro, A. M.; Stilley, J. C.; DeWinter, J. L.; Craig, K. J.; Raffuse, S. M.

2013-12-01

During peak fire season in the United States, many large wildfires often burn simultaneously across the country. Smoke from these fires can produce air quality emergencies. It is vital that incident commanders, air quality agencies, and public health officials have smoke impact information at their fingertips for evaluating where fires and smoke are and where the smoke will go next. To address the need for this kind of information, the U.S. Forest Service AirFire Team created the BlueSky Framework, a modeling system that predicts concentrations of particle pollution from wildfires. During emergency response, decision makers use BlueSky predictions to make public outreach and evacuation decisions. The models used in BlueSky predictions are computationally intensive, and the peak fire season requires significantly more computer resources than off-peak times. Purchasing enough hardware to run the number of BlueSky Framework runs that are needed during fire season is expensive and leaves idle servers running the majority of the year. The AirFire Team and STI developed BlueSky Cloud to take advantage of Amazon's virtual servers hosted in the cloud. With BlueSky Cloud, as demand increases and decreases, servers can be easily spun up and spun down at a minimal cost. Moving standard BlueSky Framework runs into the Amazon Cloud made it possible for the AirFire Team to rapidly increase the number of BlueSky Framework instances that could be run simultaneously without the costs associated with purchasing and managing servers. In this presentation, we provide an overview of the features of BlueSky Cloud, describe how the system uses Amazon Cloud, and discuss the costs and benefits of moving from privately hosted servers to a cloud-based infrastructure.

Poster Session

NASA Technical Reports Server (NTRS)

1997-01-01

In this session, Poster Session, the discussion focuses on the following topics: Development of correlative measures for the assessment of attention and memory; Biodynamical Responses of the Crewmember Head/Neck System During Emergence Ejection; Fecundation in the Sky, a Ten Years Old Experiment in Microgravity; A Modified Botex Incubator as a Transport System For Developing Crickets into Space; Chromosomal Aberrations in Peripheral Lymphocytes of Cosmonauts and Astronauts after Space Flights; Method for Establishing Long term Bone Marrow; Cultures Under Microgravity Conditions Reproduction Under Simulated Weightlessness --Mammalian in vivo Experiments Under Suspension; Towards Human Movement Analysis Without the Use of Markers; Habitability Requirements For a Cogent Mars Mission; The Saucer Concept for Space Habitats; New Way In Modeling the Growth of the Organism; The Fractionation of Hydrogen and Oxygen Stable Isotopes By Life Support Systems of Space Station "MIR"; and Effect of Space Flight on Neutrophil Function.

Passive optical sensing of atmospheric polarization for GPS denied operations

NASA Astrophysics Data System (ADS)

Aycock, Todd; Lompado, Art; Wolz, Troy; Chenault, David

2016-05-01

There is a rapidly growing need for position, navigation, and timing (PNT) capability that remains effective when GPS is degraded or denied. Naturally occurring sky polarization was used as long ago as the Vikings for navigation purposes. With current polarimetric sensors, the additional polarization information measured by these sensors can be used to increase the accuracy and the availability of this technique. The Sky Polarization Azimuth Sensing System (SkyPASS) sensor measures this naturally occurring sky polarization to give absolute heading information to less than 0.1° and offers significant performance enhancement over digital compasses and sun sensors. SkyPASS has been under development for some time for terrestrial applications, but use above the atmosphere may be possible and the performance specifications and SWAP are attractive for use as an additional pose sensor on a satellite. In this paper, we will describe the phenomenology, the sensor performance, and the latest test results of terrestrial SkyPASS; we will also discuss the potential for use above the atmosphere and the expected benefits and limitations.

Detectors for the Atacama B-mode Search experiment

NASA Astrophysics Data System (ADS)

Appel, John William

Inflation is the leading theory for explaining the initial conditions that brought about our homogeneous and isotropic Universe. It predicts the presence of gravitational waves in the early Universe, which implant a characteristic B-mode polarization pattern on the Cosmic Microwave Background (CMB). The Atacama B-mode Search (ABS) experiment is a polarimeter observing from Cerro Toco (located in the Atacama desert of Chile at an altitude of 5190 m), searching for the yet undetected B-mode signal. ABS carries 480 superconducting Transition Edge Sensor (TES) Bolometers that couple 150 GHz radiation via planar Ortho-Mode Transducers (OMTs) mounted at the output of corrugated feedhorns. The feedhorn beam is projected onto the sky through crossed Dragonian reflectors, a set of reflective and absorptive filters, and a rotating Half Wave Plate (HWP) that modulates any polarized sky signal at 10.2 Hz. The bolometers are cooled to 300 mK by a He3-He4 adsorption fridge system backed by pulse tubes. The reflectors are located within the 4 K cavity of the cryostat, while the HWP is mounted on frictionless air bearings above the cryostat window. This thesis discusses the development and construction of the ABS detector focal plane, and presents results of its performance in the field through August 2012. The ABS detector array sensitivity of 31 μKs 1/2, together with the experiment's unique set of systematic controls, and expected multi-year integration time, could detect a B-mode signal with tensor to scalar ratio r ˜ 0.1.

Sky and Elemental Planetary Mapping Via Gamma Ray Emissions

NASA Technical Reports Server (NTRS)

Roland, John M.

2011-01-01

Low-energy gamma ray emissions ((is) approximately 30keV to (is) approximately 30MeV) are significant to astrophysics because many interesting objects emit their primary energy in this regime. As such, there has been increasing demand for a complete map of the gamma ray sky, but many experiments to do so have encountered obstacles. Using an innovative method of applying the Radon Transform to data from BATSE (the Burst And Transient Source Experiment) on NASA's CGRO (Compton Gamma-Ray Observatory) mission, we have circumvented many of these issues and successfully localized many known sources to 0.5 - 1 deg accuracy. Our method, which is based on a simple 2-dimensional planar back-projection approximation of the inverse Radon transform (familiar from medical CAT-scan technology), can thus be used to image the entire sky and locate new gamma ray sources, specifically in energy bands between 200keV and 2MeV which have not been well surveyed to date. Samples of these results will be presented. This same technique can also be applied to elemental planetary surface mapping via gamma ray spectroscopy. Due to our method's simplicity and power, it could potentially improve a current map's resolution by a significant factor.

Putting The "Yee-Hah!" In Astronomy Outreach: Professional Development Through The ASP "Sky Rangers" Project

NASA Astrophysics Data System (ADS)

Manning, Jim; Gurton, S.; Hurst, A.

2010-05-01

The Astronomical Society of the Pacific is conducting a NASA-funded professional development program to help increase astronomy education and outreach capacity at national parks, nature centers, and other outdoor and environmental centers--venues that still have a dark night sky as a natural resource and a yen to interpret it for their visitors. Through online workshops and on-site workshops at national parks, the ASP staff, working in conjunction with partners from the National Park Service, National Association for Interpretation, and the Association of Science and Technology Centers, provides materials and training focusing on the sky. Participants become part of ASP's "Astronomy from the Ground Up" informational education community of practice, with ongoing options to hone their new skills. The presenter will report on early progress and lessons learned, as well as future plans, as the ASP and its partners work to help wilderness and nature interpreters put a little more "yee-hah!" in their visitor presentations aimed at the sky.

SKYMONITOR: A Global Network for Sky Brightness Measurements

NASA Astrophysics Data System (ADS)

Davis, Donald R.; Mckenna, D.; Pulvermacher, R.; Everett, M.

2010-01-01

We are implementing a global network to measure sky brightness at dark-sky critical sites with the goal of creating a multi-decade database. The heart of this project is the Night Sky Brightness Monitor (NSBM), an autonomous 2 channel photometer which measures night sky brightness in the visual wavelengths (Mckenna et al, AAS 2009). Sky brightness is measured every minute at two elevation angles typically zenith and 20 degrees to monitor brightness and transparency. The NSBM consists of two parts, a remote unit and a base station with an internet connection. Currently these devices use 2.4 Ghz transceivers with a range of 100 meters. The remote unit is battery powered with daytime recharging using a solar panel. Data received by the base unit is transmitted via email protocol to IDA offices in Tucson where it will be collected, archived and made available to the user community via a web interface. Two other versions of the NSBM are under development: one for radio sensitive areas using an optical fiber link and the second that reads data directly to a laptop for sites without internet access. NSBM units are currently undergoing field testing at two observatories. With support from the National Science Foundation, we will construct and install a total of 10 units at astronomical observatories. With additional funding, we will locate additional units at other sites such as National Parks, dark-sky preserves and other sites where dark sky preservation is crucial. We will present the current comparison with the National Park Service sky monitoring camera. We anticipate that the SKYMONITOR network will be functioning by the end of 2010.

A Method for Deriving All-Sky Evapotranspiration From the Synergistic Use of Remotely Sensed Images and Meteorological Data

NASA Astrophysics Data System (ADS)

Leng, Pei; Li, Zhao-Liang; Duan, Si-Bo; Tang, Ronglin; Gao, Mao-Fang

2017-12-01

Evapotranspiration (ET) is an important component of the water and energy cycle. The present study develops a practical approach for generating all-sky ET with the synergistic use of satellite images and meteorological data. In this approach, the ET over clear-sky pixels is estimated from a two-stage land surface temperature (LST)/fractional vegetation cover feature space method where the dry/wet edges are determined from theoretical calculations. For cloudy pixels, the Penman-Monteith equation is used to calculate the ET where no valid remotely sensed LST is available. An evaluation of the method with ET collected at ground-based large aperture scintillometer measurements at the Yucheng Comprehensive Experimental Station (YCES) in China is performed over a growth period from April to October 2010. The results show that the root-mean-square error (RMSE) and bias over clear-sky pixels are 57.3 W/m2 and 18.2 W/m2, respectively, whereas an RMSE of 69.3 W/m2 with a bias of 12.3 W/m2 can be found over cloudy pixels. Moreover, a reasonable overall RMSE of 65.3 W/m2 with a bias of 14.4 W/m2 at the YCES can be obtained under all-sky conditions, indicating a promising prospect for the derivation of all-sky ET using currently available satellite and meteorological data at a regional or global scale in future developments.

Gamma-ray spectroscopy: The diffuse galactic glow

NASA Technical Reports Server (NTRS)

Hartmann, Dieter H.

1991-01-01

The goal of this project is the development of a numerical code that provides statistical models of the sky distribution of gamma-ray lines due to the production of radioactive isotopes by ongoing Galactic nucleosynthesis. We are particularly interested in quasi-steady emission from novae, supernovae, and stellar winds, but continuum radiation and transient sources must also be considered. We have made significant progress during the first half period of this project and expect the timely completion of a code that can be applied to Oriented Scintillation Spectrometer Experiment (OSSE) Galactic plane survey data.

Daytime Sky Brightness Characterization for Persistent GEO SSA

NASA Astrophysics Data System (ADS)

Thomas, G.; Cobb, R. G.

Space Situational Awareness (SSA) is fundamental to operating in space. SSA for collision avoidance ensures safety of flight for both government and commercial spacecraft through persistent monitoring. A worldwide network of optical and radar sensors gather satellite ephemeris data from the nighttime sky. Current practice for daytime satellite tracking is limited exclusively to radar as the brightening daytime sky prevents the use of visible-band optical sensors. Radar coverage is not pervasive and results in significant daytime coverage gaps in SSA. To mitigate these gaps, optical telescopes equipped with sensors in the near-infrared band (0.75-0.9m) may be used. The diminished intensity of the background sky radiance in the near-infrared band may allow for daylight tracking further into the twilight hours. To determine the performance of a near-infrared sensor for daylight custody, the sky background radiance must first be characterized spectrally as a function of wavelength. Using a physics-based atmospheric model with access to near-real time weather, we developed a generalized model for the apparent sky brightness of the Geostationary satellite belt. The model results are then compared to measured data collected from Dayton, OH through various look and Sun angles for model validation and spectral sky radiance quantification in the visible and near-infrared bands.

The AST3 controlling and operating software suite for automatic sky survey

NASA Astrophysics Data System (ADS)

Hu, Yi; Shang, Zhaohui; Ma, Bin; Hu, Keliang

2016-07-01

We have developed a specialized software package, called ast3suite, to achieve the remote control and automatic sky survey for AST3 (Antarctic Survey Telescope) from scratch. It includes several daemon servers and many basic commands. Each program does only one single task, and they work together to make AST3 a robotic telescope. A survey script calls basic commands to carry out automatic sky survey. Ast3suite was carefully tested in Mohe, China in 2013 and has been used at Dome, Antarctica in 2015 and 2016 with the real hardware for practical sky survey. Both test results and practical using showed that ast3suite had worked very well without any manual auxiliary as we expected.

Development test results of the Portable, Reconfigurable Sky Sensor (PRSS)

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

Blattman, D.A.

1993-12-31

The protection of assets against surreptitious access from the sky is a continuing problem. The Portable, Reconfigurable Sky Sensor is designed to provide volumetric intruder detection against low-observable aircraft, helicopters, and parachutists in the sky. Multiple systems may be joined to form continuous detection volume for applications such as borders. The PRSS is resistant to nuisance alarms due to wind up to 70 mph, rain/snow up to 6 inches/hour or small targets such as birds. The PRSS has been successfully tested against multiple intrusions with altitude range from 50 to 3,000 feet and cross-range up to 3,000 feet. This papermore » summarizes some of these field tests and lists specifications and potential uses.« less

The Quiet Skies Project

ERIC Educational Resources Information Center

Rapp, Steve

2008-01-01

To help promote student awareness of the connection between radio astronomy and radio frequency interference (RFI), an inquiry-based science curriculum was developed to allow high school students to determine RFI levels in their communities. The Quiet Skies Project--the result of a collaboration between the National Aeronautics and Space…

Testing New Physics with the Cosmic Microwave Background

NASA Astrophysics Data System (ADS)

Gluscevic, Vera

2013-01-01

In my thesis work, I have developed and applied tests of new fundamental physics that utilize high-precision CMB polarization measurements. I especially focused on a wide class of dark energy models that propose existence of new scalar fields to explain accelerated expansion of the Universe. Such fields naturally exhibit a weak interaction with photons, giving rise to "cosmic birefringence"---a rotation of the polarization plane of light traveling cosmological distances, which alters the statistics of the CMB fluctuations in the sky by inducing a characteristic B-mode polarization. A birefringent rotation of the CMB would be smoking-gun evidence that dark energy is a dynamical component rather than a cosmological constant, while its absence gives clues about the allowed regions of the parameter space for new models. I developed a full-sky formalism to search for cosmic birefringence by cross-correlating CMB temperature and polarization maps, after allowing for the rotation angle to vary across the sky. With my collaborators, I also proposed a cross-correlation of the rotation-angle estimator with the CMB temperature as a novel statistical probe which can boost signal-to-noise in the case of marginal detection and help disentangle the underlying physical models. I then investigated the degeneracy between the rotation signal and the signals from other exotic scenarios that induce a similar B-mode polarization signature, such as chiral primordial gravitational waves, and demonstrated that these effects are completely separable. Finally, I applied this formalism to WMAP-7 data and derived the first CMB constraint on the power spectrum of the birefringent-rotation angle and presented forecasts for future experiments. To demonstrate the value of this analysis method beyond the search for direction-dependent cosmic birefringence, I have also used it to probe patchy screening from the epoch of cosmic reionization with WMAP-7 data.

Dark Skies, Bright Kids! Year 3

NASA Astrophysics Data System (ADS)

Whelan, David G.; Johnson, K. E.; Barcos-Munoz, L. D.; Beaton, R. L.; Borish, J.; Corby, J. F.; Dorsey, G.; Gugliucci, N. E.; Prager, B. J.; Ries, P. A.; Romero, C. E.; Sokal, K. R.; Tang, X.; Walker, L. M.; Yang, A. J.; Zasowski, G.

2012-01-01

Dark Skies, Bright Kids! (DSBK) is a program that brings astronomy education to elementary schools throughout central Virginia. In a relaxed, out-of-classroom atmosphere, we are able to foster the innate curiosity that young students have about science and the world around them. We target schools that are under-served due to their rural locale or special needs students, demonstrating that science is a fun and creative process to a segment of the population that might not otherwise be exposed to astronomy. Families are included in the learning experience during semi-annual `star parties'. Since last January, we have expanded the breadth and depth of our educational capabilities. We have developed new programs for use in our digital planetarium. We held the first Central Virginia Star Party, providing an atmosphere where local children from multiple schools were able to share their love for astronomy. Local government and University officials were also invited so that they could experience our focused science outreach. Most recently, we have become part of Ivy Creek School's Club Day activities, bringing our program to a new segment of the elementary school system in Albemarle County: those that have `low-incidence' disabilities, requiring special attention. We continue to develop a curriculum for after-school programs that functions as either a series of one-time activities or several months of focused outreach at one school. Many of these activities are provided on our website, http://www.astro.virginia.edu/dsbk/, for the wider astronomical community, including the new planetarium work. We have extended our book project to include two bilingual astronomy books called `Snapshots of the Universe,' one in Spanish and English, the other in French and English. These books introduce young people to some of the many wonders of the Universe through art and captions developed by DSBK volunteers.

Recent Advancements in the Numerical Simulation of Surface Irradiance for Solar Energy Applications: Preprint

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

Xie, Yu; Sengupta, Manajit; Deline, Chris

This paper briefly reviews the National Renewable Energy Laboratory's recent efforts on developing all-sky solar irradiance models for solar energy applications. The Fast All-sky Radiation Model for Solar applications (FARMS) utilizes the simulation of clear-sky transmittance and reflectance and a parameterization of cloud transmittance and reflectance to rapidly compute broadband irradiances on horizontal surfaces. FARMS delivers accuracy that is comparable to the two-stream approximation, but it is approximately 1,000 times faster. A FARMS-Narrowband Irradiance over Tilted surfaces (FARMS-NIT) has been developed to compute spectral irradiances on photovoltaic (PV) panels in 2002 wavelength bands. Further, FARMS-NIT has been extended for bifacialmore » PV panels.« less

A Regional, Multi-Stakeholder Collaboration for Dark-Sky Protection in Flagstaff, Arizona

NASA Astrophysics Data System (ADS)

Hall, Jeffrey C.

2018-01-01

Flagstaff, Arizona is home to almost $200M in astronomical assets, including Lowell Observatory's 4.3-meter Discovery Channel Telescope and the Navy Precision Optical Interferometer, a partnership of Lowell, the U. S. Naval Observatory, and the Naval Research Laboratory. The City of Flagstaff and surrounding Coconino County have comprehensive and effective dark-sky ordinances, but continued regional growth has the potential to degrade the area's dark skies to a level at which observatory missions could be compromised. As a result, a wide array of stakeholders (the observatories, the City, the County, local dark-sky advocates, the business and tourism communities, the national parks and monuments, the Navajo Nation, the U. S. Navy, and others) have engaged in three complementary efforts to ensure that Flagstaff and Coconino County protect the area's dark skies while meeting the needs of the various communities and providing for continued growth and development. In this poster, I will present the status of Flagstaff's conversion to LED outdoor lighting, the Mission Compatibility Study carried out by the Navy to evaluate the dark-sky effects of buildout in Flagstaff, and the Joint Land Use Study (JLUS) presently underway among all the aforementioned stakeholders. Taken in sum, the efforts represent a comprehensive and constructive approach to dark-sky preservation region-wide, and they show what can be achieved when a culture of dark-sky protection is present and deliberate efforts are undertaken to maintain it for decades to come.

X ray observations of late-type stars using the ROSAT all-sky survey

NASA Astrophysics Data System (ADS)

Linsky, Jeffrey L.; Fleming, Thomas A.

1992-03-01

The ROSAT mission made the first x ray survey of the entire sky using an imaging detector. Although ROSAT is a joint NASA/German project and involves direct American participation during its second phase of pointed observations, the all-sky survey remains the sole property of the German investigators. NASA grant represented the first use of ROSAT data analysis funds to support direct American participation in the ROSAT all-sky survey. The project involved a collaborative agreement between the Joint Institute for Laboratory Astrophysics (JILA) and the Max-Planck-Institut fur Extraterrestrische Physik (MPE) where JILA supplied MPE with a post-doctoral research associate with experience in the field of stellar (coronal) x ray emission to work within their ROSAT group. In return, members of the cool star research group at JILA were given the opportunity to collaborate on projects involving ROSAT all-sky survey data. Both sides have benefitted (and still benefit) from this arrangement since MPE suffers from a shortage of researchers who are interested in x ray emission from 'normal' stars and white dwarfs. MPE has also drawn upon experience in optical identification of x ray sources from the Einstein Extended Medium Sensitivity Survey in planning their own identification strategies for the ROSAT all-sky survey. The JILA cool stars group has benefitted since access to all-sky survey data has expanded the scope of their already extensive research programs involving multiwavelength observations of late-type stars. ROSAT was successfully launched on 1 June 1990 and conducted the bulk of the survey from 30 July 1990 to 25 January 1991. Data gaps in the survey have subsequently been made up. At the time of this writing (February 1992), the survey data have been processed once with the Standard Analysis Software System (SASS). A second processing will soon begin with improvements made to the SASS to correct errors and bugs found while carrying out scientific projects with data from the first processing. We outline the major research activities of Dr. Fleming over the past year (detailed accounts of his activities during the first two years of this grant can be found in the first-year and second-year status reports on this grant). Regarding the three specific projects which were proposed in the original proposal, two of them (White Dwarfs and Late M Dwarfs) are near completion. The results are described in two conference proceedings which are appended.

X ray observations of late-type stars using the ROSAT all-sky survey

NASA Technical Reports Server (NTRS)

Linsky, Jeffrey L.; Fleming, Thomas A.

1992-01-01

The ROSAT mission made the first x ray survey of the entire sky using an imaging detector. Although ROSAT is a joint NASA/German project and involves direct American participation during its second phase of pointed observations, the all-sky survey remains the sole property of the German investigators. NASA grant represented the first use of ROSAT data analysis funds to support direct American participation in the ROSAT all-sky survey. The project involved a collaborative agreement between the Joint Institute for Laboratory Astrophysics (JILA) and the Max-Planck-Institut fur Extraterrestrische Physik (MPE) where JILA supplied MPE with a post-doctoral research associate with experience in the field of stellar (coronal) x ray emission to work within their ROSAT group. In return, members of the cool star research group at JILA were given the opportunity to collaborate on projects involving ROSAT all-sky survey data. Both sides have benefitted (and still benefit) from this arrangement since MPE suffers from a shortage of researchers who are interested in x ray emission from 'normal' stars and white dwarfs. MPE has also drawn upon experience in optical identification of x ray sources from the Einstein Extended Medium Sensitivity Survey in planning their own identification strategies for the ROSAT all-sky survey. The JILA cool stars group has benefitted since access to all-sky survey data has expanded the scope of their already extensive research programs involving multiwavelength observations of late-type stars. ROSAT was successfully launched on 1 June 1990 and conducted the bulk of the survey from 30 July 1990 to 25 January 1991. Data gaps in the survey have subsequently been made up. At the time of this writing (February 1992), the survey data have been processed once with the Standard Analysis Software System (SASS). A second processing will soon begin with improvements made to the SASS to correct errors and bugs found while carrying out scientific projects with data from the first processing. We outline the major research activities of Dr. Fleming over the past year (detailed accounts of his activities during the first two years of this grant can be found in the first-year and second-year status reports on this grant). Regarding the three specific projects which were proposed in the original proposal, two of them (White Dwarfs and Late M Dwarfs) are near completion. The results are described in two conference proceedings which are appended.

Improved Modeling Tools Development for High Penetration Solar

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

Washom, Byron; Meagher, Kevin

2014-12-11

One of the significant objectives of the High Penetration solar research is to help the DOE understand, anticipate, and minimize grid operation impacts as more solar resources are added to the electric power system. For Task 2.2, an effective, reliable approach to predicting solar energy availability for energy generation forecasts using the University of California, San Diego (UCSD) Sky Imager technology has been demonstrated. Granular cloud and ramp forecasts for the next 5 to 20 minutes over an area of 10 square miles were developed. Sky images taken every 30 seconds are processed to determine cloud locations and cloud motionmore » vectors yielding future cloud shadow locations respective to distributed generation or utility solar power plants in the area. The performance of the method depends on cloud characteristics. On days with more advective cloud conditions, the developed method outperforms persistence forecasts by up to 30% (based on mean absolute error). On days with dynamic conditions, the method performs worse than persistence. Sky Imagers hold promise for ramp forecasting and ramp mitigation in conjunction with inverter controls and energy storage. The pre-commercial Sky Imager solar forecasting algorithm was documented with licensing information and was a Sunshot website highlight.« less

Spectroscopic and Photometric Survey of Northern Sky for the ESA PLATO space mission

NASA Astrophysics Data System (ADS)

Ženovienė, Renata; Bagdonas, Vilius; Drazdauskas, Arnas; Janulis, Rimvydas; Klebonas, Lukas; Mikolaitis, Šarūnas; Pakštienė, Erika; Tautvaišienė, Gražina

2018-04-01

The ESA-PLATO 2.0 mission will perform an in-depth analysis of the large part of the sky-sphere searching for extraterrestrial telluric-like planets. At the Molėtai Astronomical Observatory of Vilnius University, we started a spectroscopic and photometric survey of the northern sky fields that potentially will be targeted by the PLATO mission. We aim to contribute in developing the PLATO input catalogue by delivering a long-duration stellar variability information and a full spectroscopic characterization of brightest targets. First results of this survey are overviewed.

Brute-force mapmaking with compact interferometers: a MITEoR northern sky map from 128 to 175 MHz

NASA Astrophysics Data System (ADS)

Zheng, H.; Tegmark, M.; Dillon, J. S.; Liu, A.; Neben, A. R.; Tribiano, S. M.; Bradley, R. F.; Buza, V.; Ewall-Wice, A.; Gharibyan, H.; Hickish, J.; Kunz, E.; Losh, J.; Lutomirski, A.; Morgan, E.; Narayanan, S.; Perko, A.; Rosner, D.; Sanchez, N.; Schutz, K.; Valdez, M.; Villasenor, J.; Yang, H.; Zarb Adami, K.; Zelko, I.; Zheng, K.

2017-03-01

We present a new method for interferometric imaging that is ideal for the large fields of view and compact arrays common in 21 cm cosmology. We first demonstrate the method with the simulations for two very different low-frequency interferometers, the Murchison Widefield Array and the MIT Epoch of Reionization (MITEoR) experiment. We then apply the method to the MITEoR data set collected in 2013 July to obtain the first northern sky map from 128 to 175 MHz at ∼2° resolution and find an overall spectral index of -2.73 ± 0.11. The success of this imaging method bodes well for upcoming compact redundant low-frequency arrays such as Hydrogen Epoch of Reionization Array. Both the MITEoR interferometric data and the 150 MHz sky map are available at http://space.mit.edu/home/tegmark/omniscope.html.

SAGE II V7

Atmospheric Science Data Center

2017-09-06

... The series of Stratospheric Aerosol and Gas Experiments (SAGE I, II, and III) are satellite-based solar occultation ... significantly more shortwave radiation than previously thought. Clouds in a Clear Sky Scientists have detected a nearly ...

Reflective all-sky thermal infrared cloud imager.

PubMed

Redman, Brian J; Shaw, Joseph A; Nugent, Paul W; Clark, R Trevor; Piazzolla, Sabino

2018-04-30

A reflective all-sky imaging system has been built using a long-wave infrared microbolometer camera and a reflective metal sphere. This compact system was developed for measuring spatial and temporal patterns of clouds and their optical depth in support of applications including Earth-space optical communications. The camera is mounted to the side of the reflective sphere to leave the zenith sky unobstructed. The resulting geometric distortion is removed through an angular map derived from a combination of checkerboard-target imaging, geometric ray tracing, and sun-location-based alignment. A tape of high-emissivity material on the side of the reflector acts as a reference that is used to estimate and remove thermal emission from the metal sphere. Once a bias that is under continuing study was removed, sky radiance measurements from the all-sky imager in the 8-14 μm wavelength range agreed to within 0.91 W/(m 2 sr) of measurements from a previously calibrated, lens-based infrared cloud imager over its 110° field of view.

Daytime sky polarization calibration limitations

NASA Astrophysics Data System (ADS)

Harrington, David M.; Kuhn, Jeffrey R.; Ariste, Arturo López

2017-01-01

The daytime sky has recently been demonstrated as a useful calibration tool for deriving polarization cross-talk properties of large astronomical telescopes. The Daniel K. Inouye Solar Telescope and other large telescopes under construction can benefit from precise polarimetric calibration of large mirrors. Several atmospheric phenomena and instrumental errors potentially limit the technique's accuracy. At the 3.67-m AEOS telescope on Haleakala, we performed a large observing campaign with the HiVIS spectropolarimeter to identify limitations and develop algorithms for extracting consistent calibrations. Effective sampling of the telescope optical configurations and filtering of data for several derived parameters provide robustness to the derived Mueller matrix calibrations. Second-order scattering models of the sky show that this method is relatively insensitive to multiple-scattering in the sky, provided calibration observations are done in regions of high polarization degree. The technique is also insensitive to assumptions about telescope-induced polarization, provided the mirror coatings are highly reflective. Zemax-derived polarization models show agreement between the functional dependence of polarization predictions and the corresponding on-sky calibrations.

Build YOUR All-Sky View with Aladin

NASA Astrophysics Data System (ADS)

Oberto, A.; Fernique, P.; Boch, T.; Bonnarel, F.

2011-07-01

From the need to extend the display outside the boundaries of a single image, the Aladin team recently developed a new feature to visualize wide areas or even all of the sky. This all-sky view is particularly useful for visualization of very large objects and, with coverage of the whole sky, maps from the Planck satellite. To improve on this capability, some catalogs and maps have been built from many surveys (e.g., DSS, IRIS, GLIMPSE, SDSS, 2MASS) in mixed resolutions, allowing progressive display. The maps are constructed by mosaicing individual images. Now, we provide a new tool to build an all-sky view with your own images. From the images you have selected, it will compose a mosaic with several resolutions (HEALPix tessellation), and organize them to allow their progressive display in Aladin. For convenience, you can export it to a HEALPix map, or share it with the community through Aladin from your web site or eventually from the CDS image collection.

Status of the NASA SETI Sky Survey microwave observing project

NASA Technical Reports Server (NTRS)

Klein, M. J.; Gulkis, S.; Wilck, H. C.; Olsen, E. T.; Garyantes, M. F.; Burns, D. J.; Asmar, P. R.; Brady, R. B.; Deich, W. T. S.; Renzetti, N. A.

1992-01-01

The Sky Survey observing program is one of two complementary strategies that NASA plans to use in its microwave Search for Extraterrestrial Intelligence (SETI). The primary objective of the Sky Survey is to search the entire sky over the frequency range 1000-10,000 MHz for evidence of narrow band signals of extraterrestrial, intelligent origin. Spectrum analyzers with upwards of 10 million channels and data rates in excess of 10 gigabits per second are required to complete the survey in less than 7 years. To lay the foundation for the operational SETI Sky Survey, a prototype system has been built to test and refine real time signal detection algorithms, to test scan strategies and observatory control functions, and to test algorithms designed to reject radio frequency interference. This paper presents a high level description of the prototype hardware and reports on the preparations to deploy the system to the 34-m antenna at the research and development station of NASA's Deep Space Communication Complex, Goldstone, California.

Status of the NASA SETI Sky Survey microwave observing project.

PubMed

Klein, M J; Gulkis, S; Wilck, H C; Olsen, E T; Garyantes, M F; Burns, D J; Asmar, P R; Brady, R B; Deich, W T; Renzetti, N A

1992-01-01

The Sky Survey observing program is one of two complementary strategies that NASA plans to use in its microwave Search for Extraterrestrial Intelligence (SETI). The primary objective of the Sky Survey is to search the entire sky over the frequency range 1000-10,000 MHz for evidence of narrow band signals of extraterrestrial, intelligent origin. Spectrum analyzers with upwards of 10 million channels and data rates in excess of 10 gigabits per second are required to complete the survey in less than 7 years. To lay the foundation for the operational SETI Sky Survey, a prototype system has been built to test and refine real time signal detection algorithms, to test scan strategies and observatory control functions, and to test algorithms designed to reject radio frequency interference. This paper presents a high level description of the prototype hardware and software and reports on the preparations to deploy the system to the 34-m antenna at the research and development station of NASA's Deep Space Communication Complex, Goldstone, California.

The Thirty Gigahertz Instrument Receiver for the QUIJOTE Experiment: Preliminary Polarization Measurements and Systematic-Error Analysis

PubMed Central

Casas, Francisco J.; Ortiz, David; Villa, Enrique; Cano, Juan L.; Cagigas, Jaime; Pérez, Ana R.; Aja, Beatriz; Terán, J. Vicente; de la Fuente, Luisa; Artal, Eduardo; Hoyland, Roger; Génova-Santos, Ricardo

2015-01-01

This paper presents preliminary polarization measurements and systematic-error characterization of the Thirty Gigahertz Instrument receiver developed for the QUIJOTE experiment. The instrument has been designed to measure the polarization of Cosmic Microwave Background radiation from the sky, obtaining the Q, U, and I Stokes parameters of the incoming signal simultaneously. Two kinds of linearly polarized input signals have been used as excitations in the polarimeter measurement tests in the laboratory; these show consistent results in terms of the Stokes parameters obtained. A measurement-based systematic-error characterization technique has been used in order to determine the possible sources of instrumental errors and to assist in the polarimeter calibration process. PMID:26251906

Status of the Olympus experiment at CRC

NASA Technical Reports Server (NTRS)

Rogers, David V.

1992-01-01

The status of the Olympus Propagation Experiment of the Communications Research Centre in Ottawa, Canada, is briefly summarized. Path attenuation measurements at multiple frequencies correlated with concurrent dual polarized radar data provide a unique method to investigate propagation effects. An experiment of this type is being implemented by the Communications Research Centre (CRC) on the grounds of the National Research Council of Canada in Ottawa. Beacon receivers monitor signals from the Olympus satellite at 12.5, 19.77, and 29.66 GHz at a path elevation angle of 14.2 deg. Sky noise radiometers operating near the same frequencies and pointed along the same path provide additional propagation information. A colocated dual-polarized 9.6-GHz radar probes the precipitation state on the path, permitting identification of precipitation regimes that cause the observed impairments. The Olympus experiment configuration is displayed pictorially. Information on path propagation phenomena can be deduced by correlating the radar, beacon, and sky noise data. Melting layer effects and propagation losses for higher time percentages are prime interests. Data collected by Diversitel Communications during equipment verification tests are presented.

Accelerator Technology and High Energy Physics Experiments, Photonics Applications and Web Engineering, Wilga, May 2012

NASA Astrophysics Data System (ADS)

Romaniuk, Ryszard S.

2012-05-01

The paper is the second part (out of five) of the research survey of WILGA Symposium work, May 2012 Edition, concerned with accelerator technology and high energy physics experiments. It presents a digest of chosen technical work results shown by young researchers from different technical universities from this country during the XXXth Jubilee SPIE-IEEE Wilga 2012, May Edition, symposium on Photonics and Web Engineering. Topical tracks of the symposium embraced, among others, nanomaterials and nanotechnologies for photonics, sensory and nonlinear optical fibers, object oriented design of hardware, photonic metrology, optoelectronics and photonics applications, photonicselectronics co-design, optoelectronic and electronic systems for astronomy and high energy physics experiments, JET and pi-of-the sky experiments development. The symposium is an annual summary in the development of numerable Ph.D. theses carried out in this country in the area of advanced electronic and photonic systems. It is also a great occasion for SPIE, IEEE, OSA and PSP students to meet together in a large group spanning the whole country with guests from this part of Europe. A digest of Wilga references is presented [1-275].

The Conference Proceedings of the 1997 Air Transport Research Group (ATRG) of the WCTR Society. Volume 1

NASA Technical Reports Server (NTRS)

Oum, Tae Hoon (Editor); Bowen, Brent D. (Editor)

1997-01-01

Topics reported on in the proceedings include: Industrial reform and air transport development in China; the economic effects of airline deregulation and the Open-Sky policy of Korea; Open Skies in India; Japanese domestic air fares under the regulatory regime; the competitive position of airline networks; air transport and regional economic development in the European Union; and corporate dilemmas and strategies of European Airlines.

The Atacama Cosmology Telescope: Development and preliminary results of point source observations

NASA Astrophysics Data System (ADS)

Fisher, Ryan P.

2009-06-01

The Atacama Cosmology Telescope (ACT) is a six meter diameter telescope designed to measure the millimeter sky with arcminute angular resolution. The instrument is currently conducting its third season of observations from Cerro Toco in the Chilean Andes. The primary science goal of the experiment is to expand our understanding of cosmology by mapping the temperature fluctuations of the Cosmic Microwave Background (CMB) at angular scales corresponding to multipoles up to [cursive l] ~ 10000. The primary receiver for current ACT observations is the Millimeter Bolometer Array Camera (MBAC). The instrument is specially designed to observe simultaneously at 148 GHz, 218 GHz and 277 GHz. To accomplish this, the camera has three separate detector arrays, each containing approximately 1000 detectors. After discussing the ACT experiment in detail, a discussion of the development and testing of the cold readout electronics for the MBAC is presented. Currently, the ACT collaboration is in the process of generating maps of the microwave sky using our first and second season observations. The analysis used to generate these maps requires careful data calibration to produce maps of the arcminute scale CMB temperature fluctuations. Tests and applications of several elements of the ACT calibrations are presented in the context of the second season observations. Scientific exploration has already begun on preliminary maps made using these calibrations. The final portion of this thesis is dedicated to discussing the point sources observed by the ACT. A discussion of the techniques used for point source detection and photometry is followed by a presentation of our current measurements of point source spectral indices.

New High Proper Motion Stars from the Digitized Sky Survey. II. Northern Stars with 0.5" yr-1 < μ < 2.0" yr-1 at High Galactic Latitudes

NASA Astrophysics Data System (ADS)

Lépine, Sébastien; Shara, Michael M.; Rich, R. Michael

2003-08-01

In a continuation of our systematic search for high proper motion stars in the Digitized Sky Survey, we have completed the analysis of northern sky fields at Galactic latitudes above 25°. With the help of our SUPERBLINK software, a powerful automated blink comparator developed by us, we have identified 1146 stars in the magnitude range 8

SAGE II V6.20

Atmospheric Science Data Center

2017-09-06

... The series of Stratospheric Aerosol and Gas Experiments (SAGE I, II, and III) are satellite-based solar occultation ... significantly more shortwave radiation than previously thought. Clouds in a Clear Sky Scientists have detected a nearly ...

Etherospermia: Conceptual art, science and allegory in the sky-seeding project

NASA Astrophysics Data System (ADS)

Michaloudis, Ioannis; Seats, Michael

2014-11-01

This paper presents the practice of the artist/researcher Ioannis Michaloudis. It showcases his use of a space technology nanomaterial, silica aerogel, and its potential in the cultural utilization of space. Since 2001, his projects have centered around the esthetic, sculptural and conceptual use of silica aerogel. For Michaloudis, this material is highly allegorical of what he terms 'our breaking sky'. For the authors, the step towards space is a real 'bridge moment', analogous to the evolutionary progression of organisms from water to earth. In this current era of space exploration, it is clear that humans need to develop new organs and survival skills - or, cultivate new skies in response to the breaking of our atmosphere's dome. It is also clear that science and art need to collaborate more productively. To this end, it is argued that allegory provides the link between imaginability, experiment and representation in both scientific and artistic practices. Etherospermia (εθεροσπερμία) is an invented word from ether and panspermia. The Etherospermia project pursues, allegorically, the creation of new atmospheres on other planets, in order to draw attention to the degradation and destruction of the earth's protective veil. Imagine an astronaut who, during a space walk, scatters fragments of Michaloudis' silica aerogel as seed material to alter the atmospheres of other planets, making them habitable. The paper discusses nine artworks as a way of presenting the conceptual core of the etherospermia allegory.

New device for monitoring the colors of the night

NASA Astrophysics Data System (ADS)

Spoelstra, Henk

2014-05-01

The introduction of LED lighting in the outdoor environment may increase the amount of blue light in the night sky color spectrum. This can cause more light pollution due to Rayleigh scattering of the shorter wavelengths. Blue light may also have an impact on circadian rhythm of humans due to the suppression of melatonin. At present no long-term data sets of the color spectrum of the night sky are available. In order to facilitate the monitoring of levels and variations in the night sky spectrum, a low cost multi-filter instrument has been developed. Design considerations are described as well as the choice of suitable filters, which are critical - especially in the green wavelength band from 500 to 600 nm. Filters from the optical industry were chosen for this band because available astronomical filters exclude some or all of the low and high-pressure sodium lines from lamps, which are important in light pollution research. Correction factors are calculated to correct for the detector response and filter transmissions. Results at a suburban monitoring station showed that the light levels between 500 and 600 nm are dominant during clear and cloudy skies. The relative contribution of blue light increases with a clear moonless night sky. The change in color spectrum of the night sky under moonlit skies is more complex and is still under study.

Tales from the Dark Side: Teacher Professional Development , Support , Activities, Student Research & Presentations

NASA Astrophysics Data System (ADS)

Walker, C. E.; Pompea, S. M.

2013-12-01

In a partnership last Spring with Arizona Public Service, the National Optical Astronomy Observatory (NOAO) created the 'Dark-Skies Energy Education Program: Energy Awareness for a Sustainable Future'. In this program, experienced science and technology education specialists from NOAO led 2 one-day professional development workshops for thirteen 6th grade teachers on dark skies and energy education. The workshops focused on three foundational, scaffolding activities and a final student research project. This in turn culminated in a Family Science Night where students presented their projects. In between these events, our NOAO team provided support for teachers through real-time video conferencing using FaceTime. In addition to the professional development, each teacher received a kit full of resource materials to perform the activities and research project. The kit was at no cost to the teacher, school, or district. Each kit contained the latest version of a tablet, which was used to facilitate communication and support for the teachers, as well as provide all the program's written teaching materials. The activities are in accordance with state, Common Core and Next Generation Science Standards. Our NOAO instructors gave firsthand experiences on how best to use these materials in a classroom or public setting. They also discussed opportunities on how they can incorporate, adapt and expand upon the activities and research projects in the classroom. Evaluation reports from the program's independent evaluator showed that the students enjoyed learning from the three foundational activities and research projects. The project presentations by the Yuma students were outstanding in their creativity, level of effort, and scientific accuracy. To summarize the evaluations, significant changes in knowledge and attitude were made with the teachers and students (from one-on-one interviews and surveys), but behavioral changes (albeit only over a semester) seemed minimal. The AGU ED session presentation will focus on the program logistics and outcomes as well as lessons learned. The Dark Skies and Energy Education Kit

Wilga Photonics and Web Engineering 2011

NASA Astrophysics Data System (ADS)

Romaniuk, Ryszard S.

2011-10-01

The paper presents a digest of chosen technical work results shown by young researchers from different technical universities from this country during the SPIE-IEEE Wilga 2011 symposium on Photonics and Web Engineering. Topical tracks of the symposium embraced, among others, nanomaterials and nanotechnologies for photonics, sensory and nonlinear optical fibers, object oriented design of hardware, photonic metrology, optoelectronics and photonics applications, photonics-electronics co-design, optoelectronic and electronic systems for astronomy and high energy physics experiments, JET and pi-of-the sky experiments development. The symposium is an annual summary in the development of numerable Ph.D. theses carried out in this country in the area of advanced electronic and photonic systems. It is also a great occasion for SPIE, IEEE, OSA and PSP students to meet together in a large group spanning the whole country with guests from this part of Europe. A digest of Wilga references is presented [1-225].

WILGA Photonics and Web Engineering, January 2012

NASA Astrophysics Data System (ADS)

Romaniuk, Ryszard S.

2012-05-01

The paper presents a digest of chosen technical work results shown by young researchers from technical universities during the SPIE-IEEE Wilga January 2012 Symposium on Photonics and Web Engineering. Topical tracks of the symposium embraced, among others, new technologies for photonics, sensory and nonlinear optical fibers, object oriented design of hardware, photonic metrology, optoelectronics and photonics applications, photonics-electronics codesign, optoelectronic and electronic systems for astronomy and high energy physics experiments, JET and pi-of-the sky experiments development. The symposium held two times a year is a summary in the development of numerable Ph.D. theses carried out in this country in the area of advanced electronic and photonic systems. It is also a great occasion for SPIE, IEEE, OSA and PSP students to meet together in a large group spanning the whole country with guests from this part of Europe. A digest of chosen Wilga references is presented [1-268].

Comparison between solar wind latitude distribution derived from Lyman-alpha observations and Ulysses measurements

NASA Technical Reports Server (NTRS)

Quemarais, E.; Lallement, R.; Bertaux, J. L.; Sandel, B. R.

1995-01-01

The all-sky interplanetary Lyman-alpha pattern is sensitive to the latitude distribution of the solar wind because of destruction of neutral H by charge-exchange with solar wind protons. Lyman-alpha intensities recorded by Prognoz 5 and 6 in 1976 in a few parts of the sky were demonstrating a decrease of solar wind mass flux by about 30 % from equator to pole, when assuming a sinusoidal variation of this mass flux (harmonic distribution). A new analysis with a discrete variation with latitude has shown a decrease from 0 to 30 deg and then a plateau of constant mass flux up to the pole. This distribution bears a striking resemblance with Ulysses in-situ measurements, showing a clear similarity at 19 years interval. The Ulysses measurements were then used as a model input to calculate an all-sky Lyman-alpha pattern, either with a discrete model or with a harmonic solar wind variation with the same Ulysses equator-to-pole variation. There are conspicuous differences between the two Lyman-alpha patterns, in particular in the downwind region which are discussed in the context of future all-sky measurements with SWAN experiment on SOHO.

The Sky on Earth project: a synergy between formal and informal astronomy education

NASA Astrophysics Data System (ADS)

Rossi, Sabrina; Giordano, Enrica; Lanciano, Nicoletta

2016-09-01

In this paper we present the Sky on Earth project funded in 2008 by the Italian Ministry of Instruction, Research and University, inside its annual public outreach education program. The project’s goal was to realise a stable and open-access astronomical garden, where children, teachers and citizens could be engaged in investigations about day and night sky phenomena. The project was designed taking into account our prior researches in formal and informal astronomy education. It was realised in the garden of GiocheriaLaboratori, an out-of-school K-6 educational structure of Sesto San Giovanni municipality (near Milan, Italy). Setting and tools were designed with the help of some students of the ‘Altiero Spinelli’ vocational school and their science and technology teachers. Since its installation, the astronomical garden has been used in workshops and open-days, teachers’ preparation courses and research experiences. We might conclude that the Sky on Earth project represents an example of a positive and constructive collaboration between researchers, educators, high school students and teachers. It may also be considered as a potential attempt to face on the well-known gap between research in science education and school practices.

EoR Foregrounds: the Faint Extragalactic Radio Sky

NASA Astrophysics Data System (ADS)

Prandoni, Isabella

2018-05-01

A wealth of new data from upgraded and new radio interferometers are rapidly improving and transforming our understanding of the faint extra-galactic radio sky. Indeed the mounting statistics at sub-mJy and μJy flux levels is finally allowing us to get stringent observational constraints on the faint radio population and on the modeling of its various components. In this paper I will provide a brief overview of the latest results in areas that are potentially important for an accurate treatment of extra-galactic foregrounds in experiments designed to probe the Epoch of Reionization.

News "Speed Dating" for Scientists and Journalists: Conveying geoscience news in haiku-short form

NASA Astrophysics Data System (ADS)

Dybas, C. L.

2006-12-01

As Rachel Carson wrote in her 1956 book, The Sense of Wonder, it's important for everyone to develop an appreciation of "land, sea and sky." One of the best ways of getting the word out to the public about these realms is through the media. How do scientists capture the interest of the press in a society with a seemingly shorter and shorter attention span? Studies show that as the amount of scientific jargon and number of complex concepts in a news story increase, "filter-feeding" by the public of that news declines. When scientific jargon/complex concepts are few, the public "consumes" much more news. These results also apply to news story headlines: shorter headlines get the most interest. Based on these findings, one organization has started an experiment in "scientific speed dating": giving presenters three minutes to discuss results. They may have discovered something: news coverage of the research has been excellent. In today's world, conveying news about the geosciences in haiku-short form may be the best way of relating the wonders of land, sea and sky.

AURORA on MEGSAT 1: a photon counting observatory for the Earth UV night-sky background and Aurora emission

NASA Astrophysics Data System (ADS)

Monfardini, A.; Trampus, P.; Stalio, R.; Mahne, N.; Battiston, R.; Menichelli, M.; Mazzinghi, P.

2001-08-01

A low-mass, low-cost photon-counting scientific payload has been developed and launched on a commercial microsatellite in order to study the near-UV night-sky background emission with a telescope nicknamed ``Notte'' and the Aurora emission with ``Alba''. AURORA, this is the name of the experiment, will determine, with the ``Notte'' channel, the overall night-side photon background in the 300-400nm spectral range, together with a particular 2+N2 line (λc=337nm). The ``Alba'' channel, on the other hand, will study the Aurora emissions in four different spectral bands (FWHM=8.4-9.6nm) centered on: 367nm (continuum evaluation), 391nm (1-N+2), 535nm (continuum evaluation), 560nm (OI). The instrument has been launched on the 26 September, 2000 from the Baikonur cosmodrome on a modified SS18 Dnepr-1 ``Satan'' rocket. The satellite orbit is nearly circular (hapogee=648km, /e=0.0022), and the inclination of the orbital plane is 64.56°. An overview of the techniques adopted is given in this paper.

Bayesian Analysis of the Cosmic Microwave Background

NASA Technical Reports Server (NTRS)

Jewell, Jeffrey

2007-01-01

There is a wealth of cosmological information encoded in the spatial power spectrum of temperature anisotropies of the cosmic microwave background! Experiments designed to map the microwave sky are returning a flood of data (time streams of instrument response as a beam is swept over the sky) at several different frequencies (from 30 to 900 GHz), all with different resolutions and noise properties. The resulting analysis challenge is to estimate, and quantify our uncertainty in, the spatial power spectrum of the cosmic microwave background given the complexities of "missing data", foreground emission, and complicated instrumental noise. Bayesian formulation of this problem allows consistent treatment of many complexities including complicated instrumental noise and foregrounds, and can be numerically implemented with Gibbs sampling. Gibbs sampling has now been validated as an efficient, statistically exact, and practically useful method for low-resolution (as demonstrated on WMAP 1 and 3 year temperature and polarization data). Continuing development for Planck - the goal is to exploit the unique capabilities of Gibbs sampling to directly propagate uncertainties in both foreground and instrument models to total uncertainty in cosmological parameters.

Standardized Sky Partitioning for the Next Generation Astronomy and Space Science Archives

NASA Technical Reports Server (NTRS)

Lal, Nand (Technical Monitor); McLean, Brian

2004-01-01

The Johns Hopkins University and Space Telescope Science Institute are working together on this project to develop a library of standard software for data archives that will benefit the wider astronomical community. The ultimate goal was to develop and distribute a software library aimed at providing a common system for partitioning and indexing the sky in manageable sized regions and provide complex queries on the objects stored in this system. Whilst ongoing maintenance work will continue the primary goal has been completed. Most of the next generation sky surveys in the different wavelengths like 2MASS, GALEX, SDSS, GSC-II, DPOSS and FIRST have agreed on this common set of utilities. In this final report, we summarize work on the work elements assigned to the STScI project team.

ATLAS: Finding the Nearest Asteroids

NASA Astrophysics Data System (ADS)

Heinze, Aren; Tonry, John L.; Denneau, Larry; Stalder, Brian

2017-10-01

The Asteroid Terrestrial-impact Last Alert System (ATLAS) became fully operational in June 2017. Our two robotic, 0.5 meter telescopes survey the whole accessible sky every two nights from the Hawaiian mountains of Haleakala and Mauna Loa. With sensitivity to magnitude 19.5 over a field of 30 square degrees, we discover several bright near-Earth objects every month - particularly fast moving asteroids, which can slip by other surveys that scan the sky more slowly. Several important developments in 2017 have enhanced our sensitivity to small, nearby asteroids and potential impactors. We report on these developments - including optical adjustments, automated screening of detections, closer temporal spacing of images, and tolerance for large deviations from Great Circle motion on the sky - and we describe their effect in terms of measuring and discovering real objects.

Decade of wildlife tracking in the Sky Islands

Treesearch

Jessica A. Lamberton-Moreno; Sergio Avila-Villegas

2013-01-01

In 2001 Sky Island Alliance developed a citizen science program that uses track and sign identification and count surveys to monitor potential wildlife corridors throughout southeastern Arizona and southwestern New Mexico. The goal of the Wildlife Linkages Program is to protect and advocate for an interconnected landscape where wildlife, based on their ecological needs...

Highlights from 4STAR Sky-Scanning Retrievals of Aerosol Intensive Optical Properties from Multiple Field Campaigns with Detailed Comparisons of SSA Reported During SEAC4RS

NASA Technical Reports Server (NTRS)

Dunagan, Stephen E.

2016-01-01

The 4STAR (Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research) instrument combines airborne sun tracking capabilities of the Ames Airborne Tracking Sun Photometer (AATS-14) with AERONET (Aerosol Robotic Network)-like sky-scanning capability and adds state-of-the-art fiber-coupled grating spectrometry to yield hyperspectral measurements of direct solar irradiance and angularly resolved sky radiance. The combination of sun-tracking and sky-scanning capability enables retrievals of wavelength-dependent aerosol optical depth (AOD), mode-resolved aerosol size distribution (SD), asphericity, and complex refractive index, and thus also the scattering phase function, asymmetry parameter, single-scattering albedo (SSA), and absorption aerosol optical thickness (AAOT). From 2012 to 2014 4STAR participated in four major field campaigns: the U.S. Dept. of Energy's TCAP (Two-Column Aerosol Project) I & II campaigns, and NASA's SEAC4RS (Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys) and ARISE (Arctic Radiation - IceBridge Sea & Ice Experiment) campaigns. Establishing a strong performance record, 4STAR operated successfully on all flights conducted during each of these campaigns. Sky radiance spectra from scans in either constant azimuth (principal plane) or constant zenith angle (almucantar) were interspersed with direct beam measurements during level legs. During SEAC4RS and ARISE, 4STAR airborne measurements were augmented with flight-level albedo from the collocated Shortwave Spectral Flux Radiometer (SSFR) providing improved specification of below-aircraft radiative conditions for the retrieval. Calibrated radiances and retrieved products will be presented with particular emphasis on detailed comparisons of ambient SSA retrievals and measurements during SEAC4RS from 4STAR, AERONET, HSRL2 (High Spectral Resolution Lidar), and from in situ measurements.

An all-sky catalogue of solar-type dwarfs for exoplanetary transit surveys

NASA Astrophysics Data System (ADS)

Nascimbeni, V.; Piotto, G.; Ortolani, S.; Giuffrida, G.; Marrese, P. M.; Magrin, D.; Ragazzoni, R.; Pagano, I.; Rauer, H.; Cabrera, J.; Pollacco, D.; Heras, A. M.; Deleuil, M.; Gizon, L.; Granata, V.

2016-12-01

Most future surveys designed to discover transiting exoplanets, including TESS and PLATO, will target bright (V ≲ 13) and nearby solar-type stars having a spectral type later than F5. In order to enhance the probability of identifying transits, these surveys must cover a very large area on the sky, because of the intrinsically low areal density of bright targets. Unfortunately, no existing catalogue of stellar parameters is both deep and wide enough to provide a homogeneous input list. As the first Gaia data release exploitable for this purpose is expected to be released not earlier than late 2017, we have devised an improved reduced-proper-motion (RPM) method to discriminate late field dwarfs and giants by combining the fourth U.S. Naval Observatory CCD Astrograph Catalog (UCAC4) proper motions with AAVSO Photometric All-Sky Survey DR6 photometry, and relying on Radial Velocity Experiment DR4 as an external calibrator. The output, named UCAC4-RPM, is a publicly available, complete all-sky catalogue of solar-type dwarfs down to V ≃ 13.5, plus an extension to log g > 3.0 subgiants. The relatively low amount of contamination (defined as the fraction of false positives; <30 per cent) also makes UCAC4-RPM a useful tool for the past and ongoing ground-based transit surveys, which need to discard candidate signals originating from early-type or giant stars. As an application, we show how UCAC4-RPM may support the preparation of the TESS (that will map almost the entire sky) input catalogue and the input catalogue of PLATO, planned to survey more than half of the whole sky with exquisite photometric precision.

An automated extinction and sky brightness monitor for the Indian Astronomical Observatory, Hanle

NASA Astrophysics Data System (ADS)

Sharma, Tarun Kumar; Parihar, Padmakar; Banyal, R. K.; Dar, Ajaz Ahmad; Kemkar, P. M. M.; Stanzin, Urgain; Anupama, G. C.

2017-09-01

We have developed a simple and portable device that makes precise and automated measurements of night sky extinction. Our instrument uses a commercially available telephoto lens for light collection, which is retrofitted to a custom-built telescope mount, a thermoelectrically cooled CCD for imaging, and a compact enclosure with electronic control to facilitate remote observations. The instrument is also capable of measuring the sky brightness and detecting the presence of thin clouds that otherwise would remain unnoticed. The measurements of sky brightness made by our simple device are more accurate than those made using a large telescope. Another capability of the device is that it can provide an instantaneous measurement of atmospheric extinction, which is extremely useful for exploring the nature of short-term extinction variation. The instrument was designed and developed primarily in order to characterize and investigate thoroughly the Indian Astronomical Observatory (IAO), Hanle for the establishment of India's future large-telescope project. The device was installed at the IAO, Hanle in 2014 May. In this paper, we present the instrument details and discuss the results of extinction data collected for about 250 nights.

Astronomy education through hands-on photography workshops

NASA Astrophysics Data System (ADS)

Schofield, I.; Connors, M. G.; Holmberg, R.

2013-12-01

Athabasca University (AU), Athabasca University Geophysical and Geo-Space Observatories (AUGO / AUGSO), the Rotary Club of Athabasca and Science Outreach Athabasca has designed a three day science workshop entitled Photography and the Night Sky. This pilot workshop, aimed primarily at high-school aged students, serves as an introduction to observational astronomy as seen in the western Canadian night sky using digital astrophotography without the use of a telescope or tracking mount. Participants learn the layout of the night sky by proficiently photographing it using digital single lens reflex camera (DSLR) kits including telephoto and wide-angle lenses, tripod and cable release. The kits are assembled with entry-level consumer-grade camera gear as to be affordable by the participants, if they so desire to purchase their own equipment after the workshop. Basic digital photo editing is covered using free photo editing software (IrfanView). Students are given an overview of observational astronomy using interactive planetarium software (Stellarium) before heading outdoors to shoot the night sky. Photography is conducted at AU's auroral observatories, both of which possess dark open sky that is ideal for night sky viewing. If space weather conditions are favorable, there are opportunities to photograph the aurora borealis, then compare results with imagery generated by the all-sky auroral imagers located at the Geo-Space observatory. The aim of this program is to develop awareness to the science and beauty of the night sky, while promoting photography as a rewarding, lifelong hobby. Moreover, emphasis is placed on western Canada's unique subauroral location that makes aurora watching highly accessible and rewarding in 2013, the maximum of the current solar cycle.

The direct assimilation of cloud-affected satellite infrared radiance in the NCEP 3D-Hybrid system

NASA Astrophysics Data System (ADS)

Zhang, X.

2016-12-01

A function has been developed in NCEP 3D-Hybrid system to make use of Infrared radiances from Spinning Enhanced Visible and Infrared Imager (SEVIRI) on Meteosat-10(MSG-10) satellite in overcast cloudy conditions where effective cloud fractions were greater than 0.9. These cloudy radiances provide new information that currently assimilated in clear-sky condition from SEVIRI MSG-10. The model state vector is locally extended at observation locations, to include cloud top pressure as cloud parameters. This parameter describing a single-layer cloud are simultaneously estimated together with temperature and humidity inside the main analysis. Assimilation experiments have been run with the new scheme in which overcast radiance from SEVIRI MSG-10 are used in addition to the available clear-sky data. Two water vapor channels ( 6.2 and 7.3μm) and window channels (8.5, 11.2, 12.3 and 13.3μm) from SEVIRI MSG-10 are assimilated in the experiments. The overcast data locations typically represent 10% or less of the total due to the application of stringent quality control. However, The extra data that are used give rise to modified increments (largest for temperature and humidity) at and above the diagnosed cloud top. Also it improves the analysis fit to independent radiosonde observations and results in some small, but statistically significant, improvements in forecast quality.

Dark Sky Protection and Education - Izera Dark Sky Park

NASA Astrophysics Data System (ADS)

Berlicki, Arkadiusz; Kolomanski, Sylwester; Mrozek, Tomasz; Zakowicz, Grzegorz

2015-08-01

Darkness of the night sky is a natural component of our environment and should be protected against negative effects of human activities. The night darkness is necessary for balanced life of plants, animals and people. Unfortunately, development of human civilization and technology has led to the substantial increase of the night-sky brightness and to situation where nights are no more dark in many areas of the World. This phenomenon is called "light pollution" and it can be rank among such problems as chemical pollution of air, water and soil. Besides the environment, the light pollution can also affect e.g. the scientific activities of astronomers - many observatories built in the past began to be located within the glow of city lights making the night observations difficult, or even impossible.In order to protect the natural darkness of nights many so-called "dark sky parks" were established, where the darkness is preserved, similar to typical nature reserves. The role of these parks is not only conservation but also education, supporting to make society aware of how serious the problem of the light pollution is.History of the dark sky areas in Europe began on November 4, 2009 in Jizerka - a small village situated in the Izera Mountains, when Izera Dark Sky Park (IDSP) was established - it was the first transboundary dark sky park in the World. The idea of establishing that dark sky park in the Izera Mountains originated from a need to give to the society in Poland and Czech Republic the knowledge about the light pollution. Izera Dark Sky Park is a part of the astro-tourism project "Astro Izery" that combines tourist attraction of Izera Valley and astronomical education under the wonderful starry Izera sky. Besides the IDSP, the project Astro Izery consists of the set of simple astronomical instruments (gnomon, sundial), natural educational trail "Solar System Model", and astronomical events for the public. In addition, twice a year we organize a 3-4 days "Astronomy Workshop for Schools", where teachers and astronomers from Astronomical Institute (University of Wroclaw) educate the young generations in the field of astronomy and other physical sciences.

Search for extraterrestrial intelligence/high resolution microwave survey team member

NASA Technical Reports Server (NTRS)

Steffes, Paul G.

1993-01-01

This semiannual status report describes activities conducted by the Principal Investigator during the first half of this third year of the NASA High Resolution Microwave Survey (HRMS) Investigator Working Group (IWG). As a (HRMS) Team Member with primary interest in the Sky Survey activity, this investigator attended IWG meetings at NASA/Ames and U.C.-Santa Cruz in Apr. and Aug. 1992, and has traveled independently to NRAO/Kitt Peak, Arizona (April 1993) and Woodbury, Georgia (July 1993). During the July 1993 visit to the Georgia Tech Research Corporation/Woodbury Research Facility, an experiment was conducted to study the effects of interference from C-band (3.7 - 4.2 GHz) geostationary spacecraft on the Sky Survey operation in that band. At the first IWG meeting in April of this year, results of a SETI observation conducted at the 203 GHz positronium hyperfine resonance using the NRAO facility at Kitt Peak, AZ, were presented, as well as updates on the development of the spaceborne RFI data bases developed for the project. At the second meeting, results of the study of interference from C-band geostationary spacecraft were presented. Likewise, a presentation was made at the accompanying 1993 Bioastronomy Symposium describing the SETI observation at the positronium hyperfine resonance.

Leveraging Metadata to Create Interactive Images... Today!

NASA Astrophysics Data System (ADS)

Hurt, Robert L.; Squires, G. K.; Llamas, J.; Rosenthal, C.; Brinkworth, C.; Fay, J.

2011-01-01

The image gallery for NASA's Spitzer Space Telescope has been newly rebuilt to fully support the Astronomy Visualization Metadata (AVM) standard to create a new user experience both on the website and in other applications. We encapsulate all the key descriptive information for a public image, including color representations and astronomical and sky coordinates and make it accessible in a user-friendly form on the website, but also embed the same metadata within the image files themselves. Thus, images downloaded from the site will carry with them all their descriptive information. Real-world benefits include display of general metadata when such images are imported into image editing software (e.g. Photoshop) or image catalog software (e.g. iPhoto). More advanced support in Microsoft's WorldWide Telescope can open a tagged image after it has been downloaded and display it in its correct sky position, allowing comparison with observations from other observatories. An increasing number of software developers are implementing AVM support in applications and an online image archive for tagged images is under development at the Spitzer Science Center. Tagging images following the AVM offers ever-increasing benefits to public-friendly imagery in all its standard forms (JPEG, TIFF, PNG). The AVM standard is one part of the Virtual Astronomy Multimedia Project (VAMP); http://www.communicatingastronomy.org

SW radiative effect of aerosol in GRAPES_GFS

NASA Astrophysics Data System (ADS)

Chen, Qiying

2017-04-01

The aerosol particles can scatter and absorb solar radiation, and so change the shortwave radiation absorbed by the atmosphere, reached the surface and that reflected back to outer space at TOA. Since this process doesn't interact with other processes, it is called direct radiation effect. The clear sky downward SW and net SW fluxes at the surface in GRAPES_GFS of China Meteorological Administration are overestimated in Northern multitudes and Tropics. The main source of these errors is the absence of aerosol SW effect in GRAPES_GFS. The climatic aerosol mass concentration data, which include 13 kinds of aerosol and their 14 SW bands optical properties are considered in GRAPES_GFS. The calculated total optical depth, single scatter albedo and asymmetry factor are used as the input to radiation scheme. Compared with the satellite observation from MISER, the calculated total optical depth is in good consistent. The seasonal experiments show that, the summer averaged clear sky radiation fluxes at the surface are improved after including the SW effect of aerosol. The biases in the clear sky downward SW and net SW fluxes at the surface in Northern multitudes and Tropic reduced obviously. Furthermore, the weather forecast experiments also show that the skill scores in Northern hemisphere and East Asia also become better.

Using machine learning techniques to automate sky survey catalog generation

NASA Technical Reports Server (NTRS)

Fayyad, Usama M.; Roden, J. C.; Doyle, R. J.; Weir, Nicholas; Djorgovski, S. G.

1993-01-01

We describe the application of machine classification techniques to the development of an automated tool for the reduction of a large scientific data set. The 2nd Palomar Observatory Sky Survey provides comprehensive photographic coverage of the northern celestial hemisphere. The photographic plates are being digitized into images containing on the order of 10(exp 7) galaxies and 10(exp 8) stars. Since the size of this data set precludes manual analysis and classification of objects, our approach is to develop a software system which integrates independently developed techniques for image processing and data classification. Image processing routines are applied to identify and measure features of sky objects. Selected features are used to determine the classification of each object. GID3* and O-BTree, two inductive learning techniques, are used to automatically learn classification decision trees from examples. We describe the techniques used, the details of our specific application, and the initial encouraging results which indicate that our approach is well-suited to the problem. The benefits of the approach are increased data reduction throughput, consistency of classification, and the automated derivation of classification rules that will form an objective, examinable basis for classifying sky objects. Furthermore, astronomers will be freed from the tedium of an intensely visual task to pursue more challenging analysis and interpretation problems given automatically cataloged data.

Confirmation of gastric tube bedside placement with the sky blue method.

PubMed

Imamura, Takashi; Maeda, Hajime; Kinoshita, Hidetoshi; Shibukawa, Yasuko; Suda, Kiyomi; Fukuda, Yutaka; Goto, Aya; Nagasawa, Katsutoshi

2014-02-01

The purpose was to review our experiences and determine if applying the sky blue method is reliable in confirming gastric tube (GT) placement in neonates. The study population consisted of 44 infants (55 placements) who were admitted to the Takeda General Hospital between April 2012 and March 2013 and who required GT exchange. The sky blue method using indigo carmine (IC) was indicated for planned tube exchange only. Diluted IC was injected into the gastric space via the old GT just before the tube exchange. The tube was exchanged using a standard method. Then, we checked whether the diluted IC could be collected through the new GT or not. The reasons for GT placement were a gestational age of < 35 weeks in 31 (56.4%), poor sucking or swallowing disorders in 17 (30.4%), and respiratory disorders in 7 (12.7%) of the 55 placements. GT placement using the sky blue method was considered successful in 52 placements (94.4%), with the remaining 3 placements (5.6%) considered to be failures due to the inability to obtain IC from the gastric space. No adverse events were observed during the tube exchange period. Based on the results, the sky blue method can be considered to be reliable method for the confirmation of GT placement. These results also suggest that the number of radiologic evaluations performed to confirm correct replacement of the GT in infants can be reduced in the future.

Semi-Annual Status Report

NASA Technical Reports Server (NTRS)

Cohen, Martin

1998-01-01

This 6 month period continued the effort on absolute spectrally continuous stellar calibration begun in January 1991. The Midcourse Space Experiment (MSX) DCATT team has continued its analysis and intercomparisons of the Spatial Infrared Imaging Telescope (SPIRIT-III) ground calibration, the on-orbit stellar calibration (using our stellar spectra), and the on-orbit observations of the MIT Lincoln Labs. "emissive spheres". All three approaches are in very good agreement, at about the +/-3% level (absolute). This demonstrates the consistency of our overall calibration scheme and validates the context in which Infrared Space Observatory (ISO) and MSX data also reside. Final "globalization" of the overall MSX calibration is in progress, combining calibrations by stars, by the "emissive spheres" experiments, and by the NIST-traceable ground calibration. The work in support of the Infrared Telescope Satellite (IRTS) continues. I am currently calculating the contribution of diffuse starlight to the background in "dark" regions of the sky observed by the IRTS Near-IR Spectrometer. To accomplish this I am using the SKY model with a new extended wavelength capability, covering the 1.00-2.00 micron region for the first time. These calculations, together with models of the zodiacal light, will be used to seek the presence of a cosmic near-IR background. Papers VIII and IX in the calibration series appeared in this 6 month period. These describe our results on asteroid thermal nodes and anticipate the eventual production of a new network of stellar calibrators, numbering over 400 and extending over the whole sky. These will be constructed as stellar "templates", building on the legacy of our series of calibration papers. The first analyses of star counts from MSX are under way using SKY.

Model analysis for the MAGIC telescope

NASA Astrophysics Data System (ADS)

Mazin, D.; Bigongiari, C.; Goebel, F.; Moralejo, A.; Wittek, W.

The MAGIC Collaboration operates the 17m imaging Cherenkov telescope on the Canary island La Palma. The main goal of the experiment is an energy threshold below 100 GeV for primary gamma rays. The new analysis technique (model analysis) takes advantage of the high resolution (both in space and time) camera by fitting the averaged expected templates of the shower development to the measured shower images in the camera. This approach allows to recognize and reconstruct images just above the level of the night sky background light fluctuations. Progress and preliminary results of the model analysis technique will be presented.

A large-format imager for the SkyMapper Survey Telescope

NASA Astrophysics Data System (ADS)

Granlund, A.; Conroy, P. G.; Keller, S. C.; Oates, A. P.; Schmidt, B.; Waterson, M. F.; Kowald, E.; Dawson, M. I.

2006-06-01

The Research School of Astronomy and Astrophysics (RSAA) of the Australian National University (ANU) at Mt Stromlo Observatory is developing a wide-field Cassegrain Imager for the new 1.3m SkyMapper Survey Telescope under construction for Siding Spring Observatory, NSW, Australia. The Imager features a fast-readout, low-noise 268 Million pixel CCD mosaic that provides a 5.7 square degree field of view. Given the close relative sizes of the telescope and Imager, the work is proceeding in close collaboration with the telescope's manufacturer, Electro Optics Systems Pty Ltd (Canberra, Australia). The design of the SkyMapper Imager focal plane is based on E2V (Chelmsford, UK) deep depletion CCDs. These devices have 2048 x 4096 15 micron pixels, and provide a 91% filling factor in our mosaic configuration of 4 x 8 chips. In addition, the devices have excellent quantum efficiency from 300nm-950nm, near perfect cosmetics, and low-read noise, making them well suited to the all-sky ultraviolet through near-IR Southern Sky Survey to be conducted by the telescope. The array will be controlled using modified versions of the new IOTA controllers being developed for Pan-STARRS by Onaka and Tonry et al. These controllers provide a cost effective, low-volume, high speed solution for our detector read-out requirements. The system will have an integrated 6-filter exchanger, and Shack-Hartmann optics, and will be cooled by closed-cycle helium coolers. This paper will present the specifications, and opto-mechanical and detector control design of the SkyMapper Imager, including the test results of the detector characterisation and manufacturing progress.

Recent Characterization of the Night-Sky Irradiance in the Visible/Near-Infrared Spectral Band

NASA Astrophysics Data System (ADS)

Moore, Carolynn; Wood, Michael; Bender, Edward; Hart, Steve

2018-01-01

The U.S. Army RDECOM CERDEC NVESD has made numerous characterizations of the night sky over the past 45 years. Up until the last four years, the measurement devices were highly detector-limited, which led to low spectral resolution, marginal sensitivity in no-moon conditions, and the need for inferential analysis of the resulting data. In 2014, however, the PhotoResearch Model PR-745 spectro-radiometer established a new state of the art for measurement of the integrated night-sky irradiance over the Visible-to-Near-Infrared (VNIR) spectral band (400-1050nm). This has enabled characterization of no-moon night-sky irradiance with a spectral bandwidth less than 15 nanometers, even when this irradiance is attenuated by heavy clouds or forest canopy. Since 2014, we have conducted a series of night-sky data collections at remote sites across the United States. The resulting data has provided new insights into natural radiance variations, cultural lighting impacts, and the spectrally-varying attenuation caused by cloud cover and forest canopy. Several new metrics have also been developed to provide insight into these newly-found components and temporal variations. The observations, findings and conclusions of the above efforts will be presented, including planned near-term efforts to further characterize the night-sky irradiance in the Visible/Near-Infrared spectral band.

Improving precision of Pi of the Sky photometric measurements

NASA Astrophysics Data System (ADS)

Siudek, M.; Małek, K.; Mankiewicz, L.; Opiela, R.; Sokołowski, M.; Źarnecki, A. F.

Pi of the Sky is a system of robotic telescopes designed for observations of short timescale astrophysical phenomena, like prompt optical GRB emission. The apparatus is designed to monitor a large fraction of the sky with 12^{m} - 13^{m} range and time resolution of the order of 1, 10 seconds. All measurements taken by the Pi of the Sky detector located in Las Campanas Observatory (LCO) in Chile are available on the Pi of the Sky website through a dedicated interface which also allows to download the selected data. Pi of the Sky database from period 2006 - 2009 contains more than 2 billions measurements of almost 17 millions of objects. In order to facilitate analysis of variable stars we have developed a system of dedicated filters to remove bad measurements or frames. They are needed to remove measurements affected by detector imperfections (hot pixels, measurement close to CCD edge, background due to opened shutter) or observation conditions (planet or planetoid passage, moon halo). With approximate color calibration algorithm taking into account appropriate corrections based on the spectral type of reference stars the photometry algorithm can be improved further. This process is illustrated by the analysis of the BG Ind system where we have been able to reduce the total systematic uncertainty to about 0.05 magnitudes.

Matching Patterns of Light

NASA Image and Video Library

2014-11-06

These images from the Cosmic Infrared Background Experiment, or CIBER, show large patches of the sky at two different infrared wavelengths 1.1 microns and 1.6 microns after all known galaxies have been subtracted out and the images smoothed.

Reflective all-sky thermal infrared cloud imager

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

Redman, Brian J.; Shaw, Joseph A.; Nugent, Paul W.

A reflective all-sky imaging system has been built using a long-wave infrared microbolometer camera and a reflective metal sphere. This compact system was developed for measuring spatial and temporal patterns of clouds and their optical depth in support of applications including Earth-space optical communications. The camera is mounted to the side of the reflective sphere to leave the zenith sky unobstructed. The resulting geometric distortion is removed through an angular map derived from a combination of checkerboard-target imaging, geometric ray tracing, and sun-location-based alignment. A tape of high-emissivity material on the side of the reflector acts as a reference thatmore » is used to estimate and remove thermal emission from the metal sphere. In conclusion, once a bias that is under continuing study was removed, sky radiance measurements from the all-sky imager in the 8-14 μm wavelength range agreed to within 0.91 W/(m 2 sr) of measurements from a previously calibrated, lens-based infrared cloud imager over its 110° field of view.« less

Reflective all-sky thermal infrared cloud imager

DOE PAGES

Redman, Brian J.; Shaw, Joseph A.; Nugent, Paul W.; ...

2018-04-17

A reflective all-sky imaging system has been built using a long-wave infrared microbolometer camera and a reflective metal sphere. This compact system was developed for measuring spatial and temporal patterns of clouds and their optical depth in support of applications including Earth-space optical communications. The camera is mounted to the side of the reflective sphere to leave the zenith sky unobstructed. The resulting geometric distortion is removed through an angular map derived from a combination of checkerboard-target imaging, geometric ray tracing, and sun-location-based alignment. A tape of high-emissivity material on the side of the reflector acts as a reference thatmore » is used to estimate and remove thermal emission from the metal sphere. In conclusion, once a bias that is under continuing study was removed, sky radiance measurements from the all-sky imager in the 8-14 μm wavelength range agreed to within 0.91 W/(m 2 sr) of measurements from a previously calibrated, lens-based infrared cloud imager over its 110° field of view.« less

Session 21.6: Preserving Dark Skies and Protecting Against Light Pollution in a World Heritage Framework

NASA Astrophysics Data System (ADS)

Smith, Malcolm G.

2016-10-01

This session opened with a crucial explanation by Michel Cotte of how astronomers first need to understand how to apply UNESCO World Heritage Criteria if they want to motivate their government(s) to make the case to UNESCO for World Heritage recognition. UNESCO World Heritage cannot be obtained just to protect dark skies. Much more detail of this and the other presentations in this session, along with many images, can be found at the session website: http://www.noao.edu/education/IAUGA2015FM21. The next speaker, John Hearnshaw, described the Aoraki Mackenzie International Dark Sky Reserve and the work it carries out . This was followed by a wide-ranging summary (by Dan Duriscoe and Nate Ament) of the U.S. National Park Service (NPS) Night Skies Program. The abstract of Cipriano's Marin's paper, ``Developing Starlight connections with UNESCO sites through the Biosphere Smart" was shown in his absence. The final presentation (by Arkadiusz Berlicki, S. Kolomanksi and T. Mrozek) discussed the bi-national Izera Dark Sky Park.

The Aquarius Simulator and Cold-Sky Calibration

NASA Technical Reports Server (NTRS)

Le Vine, David M.; Dinnat, Emmanuel P.; Abraham, Saji; deMatthaeis, Paolo; Wentz, Frank J.

2011-01-01

A numerical simulator has been developed to study remote sensing from space in the spectral window at 1.413 GHz (L-band), and it has been used to optimize the cold-sky calibration (CSC) for the Aquarius radiometers. The celestial sky is a common cold reference in microwave radiometry. It is currently being used by the Soil Moisture and Ocean Salinity satellite, and it is planned that, after launch, the Aquarius/SAC-D observatory will periodically rotate to view "cold sky" as part of the calibration plan. Although radiation from the celestial sky is stable and relatively well known, it varies with location. In addition, radiation from the Earth below contributes to the measured signal through the antenna back lobes and also varies along the orbit. Both effects must be taken into account for a careful calibration. The numerical simulator has been used with the Aquarius configuration (antennas and orbit) to investigate these issues and determine optimum conditions for performing a CSC. This paper provides an overview of the simulator and the analysis leading to the selection of the optimum locations for a CSC.

Rocket-borne and ground-based measurements in support of the field-widened interferometer experiment - sergeant a30. 276

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

Ulwick, J.C.; Allred, G.D.; Baker, K.D.

1985-05-28

In April 1983 Utah State University and Air Force Geophysics Laboratory experimenters launched a Sergeant (A30.276) sounding rocket from the Poker Flat Research Range, Alaska. The prime purpose of the flight was to obtain infrared-spectral measurements in the 2-1.5 micrometer m range during an auroral event. In addition to the prime experiment, which has already been reported, the payload contained four photometers, and energy deposition scintillator and an atomic oxygen detector to gather in-situ supporting data. Simultaneously, all-sky television, meridian scanning photometers, riometer, and magnetometers supported the flight from ground-based measuring sites. This report presents a summary of the rocketbornemore » supporting instruments and the data they gathered and provides a time/intensity history of the event as documented by the ground-based meridian scanners and all-sky television.« less

Experiments on the CMB Spectrum, Big Jets Model and Their Implications for the Missing Half of the Universe

NASA Astrophysics Data System (ADS)

Hsu, Leonardo; Hsu, Jong-Ping

2018-01-01

Based on the limiting continuation of Lorentz-Poincaré invariance, we propose an alternative formulation of the generalized Planck distribution for inertial and noninertial frames. The Lorentz invariant Planck distribution law leads to a new physical interpretation of the dipole anisotropy of the Cosmic Microwave Background. The Big Jets model predicts a distant `antimatter blackbody,' whose radiations could make 50% of the sky very slightly warmer than the isotropic CMB temperature TCMB with a cosine function. The other 50% of the sky has the same isotropic temperature TCMB. Thus, we could have a pseudo-dipole anisotropy because the microwaves emitted from the antimatter blackbody are totally absorbed by our matter blackbody. We suggest that accurate data of satellite experiments might be used to search for the pseudo-dipole anisotropy and the missing half of the antimatter universe.

The Polar Night Nitric Oxide Experiment

NASA Image and Video Library

2017-12-08

The Polar Night Nitric Oxide or PolarNOx experiment from Virginia Tech is launched aboard a NASA Black Brant IX sounding rocket at 8:45 a.m. EST, Jan. 27, from the Poker Flat Research Range in Alaska. PolarNOx is measuring nitric oxide in the polar night sky. Nitric oxide in the polar night sky is created by auroras. Under appropriate conditions it can be transported to the stratosphere where it may destroy ozone resulting in possible changes in stratospheric temperature and wind and may even impact the circulation at Earth’s surface. Credit: NASA/Wallops/Jamie Adkins NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Out of the Lab...Into the Real World

NASA Technical Reports Server (NTRS)

1999-01-01

Big Sky Laser Technologies of Bozeman, MT is a developer of compact, ruggedized commercial and developmental laser systems, including small medical lasers and Lidars used in NASA tracking applications. Company engineers developing new laser products determined that NASA technology for detection and control of prelasing in a Q-switched laser would be of value to them in at least two of their product lines. Big Sky Laser's CFR-800 unit is based on NASA technology to which they obtained a non-exclusive patent.

The Conference Proceedings of the 1997 Air Transport Research Group (ATRG) of the WCTR Society. Volume 1

NASA Technical Reports Server (NTRS)

Own, Tae Hoon (Editor); Bowen, Brent D. (Editor)

1997-01-01

The Aviation Institute University of Nebraska at Omaha (UNO) Monograph series has published the Conference Proceedings of the 1997 Air Transport Research Group (ATRG) of the World Conference on Transportation Research Society (WCTR) volume 1, number 3. The topics included in this document are: 1) Industrial Reform and Air Transport Development in China; 2) The Economic Effects of Airline Deregulation and the Open-Sky Policy of Korea; 3) The Economic Effects of Airline Deregulation and the Open-Sky Policy of Korea; 4) "Open Skies" in India-Is the policy succeeding? 5) The Japanese Domestic Air Fares under the Regulatory Regime: What will be expected after the revision of current charging system? 6) The Competitive Position of Airline Networks; and 7) Air Transport and Regional Economic Development in the European Union.

All sky imaging observations in visible and infrared waveband for validation of satellite cloud and aerosol products

NASA Astrophysics Data System (ADS)

Lu, Daren; Huo, Juan; Zhang, W.; Liu, J.

A series of satellite sensors in visible and infrared wavelengths have been successfully operated on board a number of research satellites, e.g. NOAA/AVHRR, the MODIS onboard Terra and Aqua, etc. A number of cloud and aerosol products are produced and released in recent years. However, the validation of the product quality and accuracy are still a challenge to the atmospheric remote sensing community. In this paper, we suggest a ground based validation scheme for satellite-derived cloud and aerosol products by using combined visible and thermal infrared all sky imaging observations as well as surface meteorological observations. In the scheme, a visible digital camera with a fish-eye lens is used to continuously monitor the all sky with the view angle greater than 180 deg. The digital camera system is calibrated for both its geometry and radiance (broad blue, green, and red band) so as to a retrieval method can be used to detect the clear and cloudy sky spatial distribution and their temporal variations. A calibrated scanning thermal infrared thermometer is used to monitor the all sky brightness temperature distribution. An algorithm is developed to detect the clear and cloudy sky as well as cloud base height by using sky brightness distribution and surface temperature and humidity as input. Based on these composite retrieval of clear and cloudy sky distribution, it can be used to validate the satellite retrievals in the sense of real-simultaneous comparison and statistics, respectively. What will be presented in this talk include the results of the field observations and comparisons completed in Beijing (40 deg N, 116.5 deg E) in year 2003 and 2004. This work is supported by NSFC grant No. 4002700, and MOST grant No 2001CCA02200

Photometric Assessment of Night Sky Quality over Chaco Culture National Historical Park

NASA Astrophysics Data System (ADS)

Hung, Li-Wei; Duriscoe, Dan M.; White, Jeremy M.; Meadows, Bob; Anderson, Sharolyn J.

2018-06-01

The US National Park Service (NPS) characterizes night sky conditions over Chaco Culture National Historical Park using measurements in the park and satellite data. The park is located near the geographic center of the San Juan Basin of northwestern New Mexico and the adjacent Four Corners state. In the park, we capture a series of night sky images in V-band using our mobile camera system on nine nights from 2001 to 2016 at four sites. We perform absolute photometric calibration and determine the image placement to obtain multiple 45-million-pixel mosaic images of the entire night sky. We also model the regional night sky conditions in and around the park based on 2016 VIIRS satellite data. The average zenith brightness is 21.5 mag/arcsec2, and the whole sky is only ~16% brighter than the natural conditions. The faintest stars visible to naked eyes have magnitude of approximately 7.0, reaching the sensitivity limit of human eyes. The main impacts to Chaco’s night sky quality are the light domes from Albuquerque, Rio Rancho, Farmington, Bloomfield, Gallup, Santa Fe, Grants, and Crown Point. A few of these light domes exceed the natural brightness of the Milky Way. Additionally, glare sources from oil and gas development sites are visible along the north and east horizons. Overall, the night sky quality at Chaco Culture National Historical Park is very good. The park preserves to a large extent the natural illumination cycles, providing a refuge for crepuscular and nocturnal species. During clear and dark nights, visitors have an opportunity to see the Milky Way from nearly horizon to horizon, complete constellations, and faint astronomical objects and natural sources of light such as the Andromeda Galaxy, zodiacal light, and airglow.

Light-pollution measurement with the Wide-field all-sky image analyzing monitoring system

NASA Astrophysics Data System (ADS)

Vítek, S.

2017-07-01

The purpose of this experiment was to measure light pollution in the capital of Czech Republic, Prague. As a measuring instrument is used calibrated consumer level digital single reflex camera with IR cut filter, therefore, the paper reports results of measuring and monitoring of the light pollution in the wavelength range of 390 - 700 nm, which most affects visual range astronomy. Combining frames of different exposure times made with a digital camera coupled with fish-eye lens allow to create high dynamic range images, contain meaningful values, so such a system can provide absolute values of the sky brightness.

Final mission design for IRAS

NASA Technical Reports Server (NTRS)

Mclaughlin, W. I.

1984-01-01

The Infrared Astronomical Satellite (IRAS) was operated on orbit from 26 January to 22 November 1983 (GMT). Its primary purpose, successfully accomplished, was to conduct an all-sky survey in the infrared from 8 to 120 microns. The mission design for this project featured orbit selection; numerous exercises in the geometry of the sphere; computer simulation of mission, sky, and telescope; and an active interface with the IRAS Science Team. In addition to mission design, the subject of mission planning after launch is addressed. The paper makes extensive use of reference to other works on the topic and seeks to derive some general conclusions on the subject based upon the IRAS experience.

Mapping automotive like controls to a general aviation aircraft

NASA Astrophysics Data System (ADS)

Carvalho, Christopher G.

The purpose of this thesis was to develop fly-by-wire control laws enabling a general aviation aircraft to be flown with automotive controls, i.e. a steering wheel and gas/brake pedals. There was a six speed shifter used to change the flight mode of the aircraft. This essentially allows the pilot to have control over different aspects of the flight profile such as climb/descend or cruise. A highway in the sky was used to aid in the navigation since it is not intuitive to people without flight experience how to navigate from the sky or when to climb and descend. Many believe that general aviation could become as widespread as the automobile. Every person could have a personal aircraft at their disposal and it would be as easy to operate as driving an automobile. The goal of this thesis is to fuse the ease of drivability of a car with flight of a small general aviation aircraft. A standard automotive control hardware setup coupled with variably autonomous control laws will allow new pilots to fly a plane as easily as driving a car. The idea is that new pilots will require very little training to become proficient with these controls. Pilots with little time to stay current can maintain their skills simply by driving a car which is typically a daily activity. A human factors study was conducted to determine the feasibility of the applied control techniques. Pilot performance metrics were developed to compare candidates with no aviation background and experienced pilots. After analyzing the relative performance between pilots and non-pilots, it has been determined that the control system is robust and easy to learn. Candidates with no aviation experience whatsoever can learn to fly an aircraft as safely and efficiently as someone with hundreds of hours of flight experience using these controls.

Predicting the sky from 30 MHz to 800 GHz: the extended Global Sky Model

NASA Astrophysics Data System (ADS)

Liu, Adrian

We propose to construct the extended Global Sky Model (eGSM), a software package and associated data products that are capable of generating maps of the sky at any frequency within a broad range (30 MHz to 800 GHz). The eGSM is constructed from archival data, and its outputs will include not only "best estimate" sky maps, but also accurate error bars and the ability to generate random realizations of missing modes in the input data. Such views of the sky are crucial in the practice of precision cosmology, where our ability to constrain cosmological parameters and detect new phenomena (such as B-mode signatures from primordial gravitational waves, or spectral distortions of the Cosmic Microwave Background; CMB) rests crucially on our ability to remove systematic foreground contamination. Doing so requires empirical measurements of the foreground sky brightness (such as that arising from Galactic synchrotron radiation, among other sources), which are typically performed only at select narrow wavelength ranges. We aim to transcend traditional wavelength limits by optimally combining existing data to provide a comprehensive view of the foreground sky at any frequency within the broad range of 30 MHz to 800 GHz. Previous efforts to interpolate between multi-frequency maps resulted in the Global Sky Model (GSM) of de Oliveira-Costa et al. (2008), a software package that outputs foreground maps at any frequency of the user's choosing between 10 MHz and 100 GHz. However, the GSM has a number of shortcomings. First and foremost, the GSM does not include the latest archival data from the Planck satellite. Multi-frequency models depend crucially on data from Planck, WMAP, and COBE to provide high-frequency "anchor" maps. Another crucial shortcoming is the lack of error bars in the output maps. Finally, the GSM is only able to predict temperature (i.e., total intensity) maps, and not polarization information. With the recent release of Planck's polarized data products, the time is ripe for the inclusion of polarization and a general update of the GSM. In its first two phases, our proposed eGSM project will incorporate new data and improve analysis methods to eliminate all of the aforementioned flaws. The eGSM will have broad implications for future cosmological probes, including surveys of the highly redshifted 21 cm line (such as the proposed Dark Ages Radio Explorer satellite mission) and CMB experiments (such as the Primordial Inflation Polarization Explorer and the Primordial Inflation Explorer) targeting primordial B-mode polarization or spectral distortions. Forecasting exercises for such future experiments must include polarized foregrounds below current detection limits. The third phase of the eGSM will result in a software package that provides random realizations of dim polarized foregrounds that are below the sensitivities of current instruments. This requires the quantification of non-Gaussian and non-isotropic statistics of existing foreground surveys, adding value to existing archival maps. eGSM data products will be publicly hosted on the Legacy Archive for Microwave Background Data Analysis (LAMBDA) archive, including a publicly released code that enables future foreground surveys (whether ground-based or space-based) to easily incorporate additional data into the existing archive, further refining our model and maximizing the impact of existing archives beyond the lifetime of this proposal.

Diurnal variability of regional cloud and clear-sky radiative parameters derived from GOES data. I - Analysis method. II - November 1978 cloud distributions. III - November 1978 radiative parameters

NASA Technical Reports Server (NTRS)

Minnis, P.; Harrison, E. F.

1984-01-01

Cloud cover is one of the most important variables affecting the earth radiation budget (ERB) and, ultimately, the global climate. The present investigation is concerned with several aspects of the effects of extended cloudiness, taking into account hourly visible and infrared data from the Geostationary Operational Environmental Satelite (GOES). A methodology called the hybrid bispectral threshold method is developed to extract regional cloud amounts at three levels in the atmosphere, effective cloud-top temperatures, clear-sky temperature and cloud and clear-sky visible reflectance characteristics from GOES data. The diurnal variations are examined in low, middle, high, and total cloudiness determined with this methodology for November 1978. The bulk, broadband radiative properties of the resultant cloud and clear-sky data are estimated to determine the possible effect of the diurnal variability of regional cloudiness on the interpretation of ERB measurements.

The COBE cosmic 3 K anisotropy experiment: A gravity wave and cosmic string probe

NASA Technical Reports Server (NTRS)

Bennett, Charles L.; Smoot, George F.

1989-01-01

Among the experiments to be carried into orbit next year, by the COBE satellite, are differential microwave radiometers. They will make sensitive all-sky maps of the temperature of the cosmic microwave background radiation at three frequencies, giving dipole, quadrupole, and higher order multipole measurements of the background radiation. The experiment will either detect, or place significant constraints on, the existence of cosmic strings and long wavelength gravity waves.

Global aerosol typing from a combination of A-Train satellite observations in clear-sky and above clouds

NASA Astrophysics Data System (ADS)

Kacenelenbogen, M. S.; Russell, P. B.; Vaughan, M.; Redemann, J.; Shinozuka, Y.; Livingston, J. M.; Zhang, Q.

2014-12-01

According to the 5th Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), the model estimates of Radiative Forcing due to aerosol-radiation interactions (RFari) for individual aerosol types are less certain than the total RFari [Boucher et al., 2013]. For example, the RFari specific to Black Carbon (BC) is uncertain due to an underestimation of its mass concentration near source regions [Koch et al., 2009]. Several recent studies have evaluated chemical transport model (CTM) predictions using observations of aerosol optical properties such as Aerosol Optical Depth (AOD) or Single Scattering Albedo (SSA) from satellite or ground-based instruments (e.g., Huneeus et al., [2010]). However, most passive remote sensing instruments fail to provide a comprehensive assessment of the particle type without further analysis and combination of measurements. To improve the predictions of aerosol composition in CTMs, we have developed an aerosol classification algorithm (called Specified Clustering and Mahalanobis Classification, SCMC) that assigns an aerosol type to multi-parameter retrievals by spaceborne, airborne or ground based passive remote sensing instruments [Russell et al., 2014]. The aerosol types identified by our scheme are pure dust, polluted dust, urban-industrial/developed economy, urban-industrial/developing economy, dark biomass smoke, light biomass smoke and pure marine. First, we apply the SCMC method to five years of clear-sky space-borne POLDER observations over Greece. We then use the aerosol extinction and SSA spectra retrieved from a combination of MODIS, OMI and CALIOP clear-sky observations to infer the aerosol type over the globe in 2007. Finally, we will extend the spaceborne aerosol classification from clear-sky to above low opaque water clouds using a combination of CALIOP AOD and backscatter observations and OMI absorption AOD values from near-by clear-sky pixels.

NSF Internships in Public Science Education: Sensing the Radio Sky

NASA Astrophysics Data System (ADS)

Hund, L.; Boltuch, D.; Fultz, C.; Buck, S.; Smith, T.; Harris, R.; Moffett, D.; LaFratta, M.; Walsh, L.; Castelaz, M. W.

2005-12-01

The intent of the "Sensing the Radio Sky" project is to teach high school students the concepts and relevance of radio astronomy through presentations in STARLAB portable planetariums. The two year project began in the summer of 2004. A total of twelve interns and four faculty mentors from Furman University and UNCA have participated at the Pisgah Astronomical Research Institute to develop the Radio Sky project. The project united physics and multimedia majors and allowed these students to apply their knowledge of different disciplines to a common goal. One component of the project is the development and production of a cylinder to be displayed in portable STARLAB planetariums. The cylinder gives a thorough view of the Milky Way and of several other celestial sources in radio wavelengths, yet these images are difficult to perceive without prior knowledge of radio astronomy. Consequently, the Radio Sky team created a multimedia presentation to accompany the cylinder. This multimedia component contains six informative lessons on radio astronomy assembled by the physics interns and numerous illustrations and animations created by the multimedia interns. The cylinder and multimedia components complement each other and provide a unique, thorough, and highly intelligible perspective on radio astronomy. The project is near completion and the final draft will be sent to Learning Technologies, Inc., for marketing to owners of STARLAB planetariums throughout the world. The development of the Radio Sky project has also provided a template for potential similar projects that examine our universe in different wavelengths, such as gamma ray, x-ray, and infrared. We acknowledge support from the NSF Internship in Public Science Education Program grant number 0324729.

Aerosol radiative effects and their trends under clear-sky situations over Europe

NASA Astrophysics Data System (ADS)

Bartok, Blanka

2017-04-01

In the literature great uncertainties ca be found regarding radiative effects of aerosols on the energy budget of the atmosphere (IPCC, 2013). In the study the aerosols radiative effects on clear-sky solar radiation are quantified over Europe using empirical and physical modelling approaches. The values of aerosol radiation effect are determined by the MAGIC radiation code. In the first run clear-sky radiation is calculated integrating KINEE/MPI/Aerocom aerosol climatology and ERA-INTERIM water vapour multiannual monthly means. In the next run the clear-sky radiation are also calculated ignoring aerosol data (adjusted to 0) from the algorithm. Both runs were carried out for each months of the year, taking into account the varying astrological factors. The difference between the aerosol-included and aerosol-free clear-sky radiation is equal to the absolute aerosol radiative effect in W/m2. The annual mean of the surface aerosol radiative effects in clear-sky situations over Europe is -7.1 ± 2.9 W/m2, high values are representing the central part of the continent and the Mediterranean Basin. Furthermore the trends of the aerosol radiative effects are also determined for the period of 2001-2012. First a linear fitting is elaborated between the aerosol optical depth (AOT) built in the MAGIC code and its aerosol radiative effect calculated by the code. Next, based on these linear functions a radiative effect values are assigned to each monthly AOT500 value available from the Moderate Resolution Imaging Spectroradiometer (MODIS) Terra Level-3 experiment. In this way a new dataset of aerosol radiative effect for the period of 2001-2012 has been created. Beside of this approach the changes in aerosol radiative effects are also calculated based on ground-based clear-sky radiation trends. This approach is used as a validation of the method applied in earlier stage, mainly for the linear fitting. The starting point of this approach is to elaborate the trends of clear-sky radiation controlled by the effects of aerosols and water vapour. If we subtract the water vapour effects also calculated by MAGIC radiation code from this trend, the magnitude of the trends in aerosol radiative effects can be estimated. In this case it is assumed that the two effects do not amplify and do not cancel each other, and their arithmetic sum gives the change in clear-sky radiation trend. The two approaches give good fit, based on the direct (modelled) approach the annual trend of the aerosol radiative effects on clear-sky solar surface radiation is -4.41 W/m2 per decade for the period of 2001-2013, while in the case of the indirect approach (based on clear-sky trends) this trend is found to be -4.46 W/m2 per decade.

HEAO C-1 gamma-ray spectrometer. [experimental design

NASA Technical Reports Server (NTRS)

Mahoney, W. A.; Ling, J. C.; Willett, J. B.; Jacobson, A. S.

1978-01-01

The gamma-ray spectroscopy experiment to be launched on the third High Energy Astronomy Observatory (HEAO C) will perform a complete sky search for narrow gamma-ray line emission to the level of about 00001 photons/sq cm -sec for steady point sources. The design of this experiment and its performance based on testing and calibration to date are discussed.

Results of experiments related to contact of mine-spoils water with coal, West Decker and Big Sky Mines, southeastern Montana

USGS Publications Warehouse

Davis, R.E.; Dodge, K.A.

1986-01-01

Batch-mixing experiments using spoils water and coal from the West Decker and Big Sky Mines were conducted to determine possible chemical changes in water moving from coal-mine spoils through a coal aquifer. The spoils water was combined with air-dried and oven-dried chunks of coal and air-dried and oven-dried crushed coal at a 1:1 weight ratio, mixed for 2 hr, and separated after a total contact time of 24 hr. The dissolved-solids concentration in water used in the experiments decreased an average 210 mg/liter (5-10%). Other chemical changes included general decreases in the concentrations of magnesium, potassium, and bicarbonate, and general increases in the concentrations of barium and boron. The magnitude of the changes increased as the surface area of the coal increased. The quantity of extractable cations and exchangeable cations on the post-mixing coal was larger than on the pre-mixing coal. Equilibrium and mass-transfer relations indicate that adsorption reactions or ion-exchange and precipitation reactions, or both, probably are the major reactions responsible for the chemical changes observed in the experiments. (Authors ' abstract)

Dark Skies as a Universal Resource: Citizen Scientists Measuring Sky Brightness

NASA Astrophysics Data System (ADS)

Walker, C. E.; Isbell, D.; Pompea, S. M.

2007-12-01

The international star-hunting event known as GLOBE at Night returned March 8-21, 2007 in two flavors: the classic GLOBE at Night activity incorporating unaided-eye observations which debuted last year, and a new effort to obtain precise measurements of urban dark skies using digital sky-brightness meters. Both flavors of the program were designed to aid in heightening the awareness about the impact of artificial lighting on local environments, and the ongoing loss of a dark night sky as a natural resource for much of the world's population. To make possible the digital GLOBE at Night program, NSF funded 135 low-cost, digital sky-quality meter (manufactured by Unihedron). With these, citizen-scientists took direct measurements of the integrated sky brightness across a wide swath of night sky. Along with related materials developed by the National Optical Astronomy Observatory (NOAO), the meters were distributed to citizen-scientists in 21 U.S. states plus Washington DC, and in 5 other countries, including Chile, where NOAO has a major observatory. The citizen- scientists were selected from teachers, their students, astronomers at mountain-top observatories, International Dark-Sky Association members and staff from 19 small science centers. Most sites had a coordinator, who instructed local educators in the proper use of the meters and develop a plan to share them as widely as possible during the 2-week window. The local teams pooled their data for regional analysis and in some cases shared the results with their schools and local policymakers. Building upon the worldwide participation sparked by the first GLOBE at Night campaign in March 2006, the observations this year approached 8500 (from 60 countries), 85% higher than the number from last year. The success of GLOBE at Night 2007 is a major step toward the International Year of Astronomy in 2009, when one goal is to make the digital data collection into a worldwide activity. In this presentation, we will outline the set-up for the digital part of the program, the outcome and the plans for the future. GLOBE at Night has been a collaboration between NOAO, the GLOBE program, the IDA, CADIAS and Windows to the Universe. NOAO is operated by the Association of Universities for Research in Astronomy, Inc. under cooperative agreement with the National Science Foundation. The digital GLOBE at Night program described was supported by a grant to NOAO by the NSF.

The clear-sky greenhouse effect sensitivity to a sea surface temperature change

NASA Technical Reports Server (NTRS)

Duvel, J. PH.; Breon, F. M.

1991-01-01

The clear-sky greenhouse effect response to a sea surface temperature (SST or Ts) change is studied using outgoing clear-sky longwave radiation measurements from the Earth Radiation Budget Experiment. Considering geographical distributions for July 1987, the relation between the SST, the greenhouse effect (defined as the outgoing infrared flux trapped by atmospheric gases), and the precipitable water vapor content (W), estimated by the Special Sensor Microwave Imager, is analyzed first. A fairly linear relation between W and the normalized greenhouse effect g, is found. On the contrary, the SST dependence of both W and g exhibits nonlinearities with, especially, a large increase for SST above 25 C. This enhanced sensitivity of g and W can be interpreted in part by a corresponding large increase of atmospheric water vapor content related to the transition from subtropical dry regions to equatorial moist regions. Using two years of data (1985 and 1986), the normalized greenhouse effect sensitivity to the sea surface temperature is computed from the interannual variation of monthly mean values.

An evaluation of skylight polarization patterns for navigation.

PubMed

Ma, Tao; Hu, Xiaoping; Zhang, Lilian; Lian, Junxiang; He, Xiaofeng; Wang, Yujie; Xian, Zhiwen

2015-03-10

Skylight polarization provides a significant navigation cue for certain polarization-sensitive animals. However, the precision of the angle of polarization (AOP) of skylight for vehicle orientation is not clear. An evaluation of AOP must be performed before it is utilized. This paper reports an evaluation of AOP of skylight by measuring the skylight polarization patterns of clear and cloudy skies using a full-sky imaging polarimetry system. AOP measurements of skylight are compared with the pattern calculated by the single-scattering Rayleigh model and these differences are quantified. The relationship between the degree of polarization (DOP) and the deviation of AOP of skylight is thoroughly studied. Based on these, a solar meridian extracted method is presented. The results of experiments reveal that the DOP is a key parameter to indicate the accuracy of AOP measurements, and all the output solar meridian orientations extracted by our method in both clear and cloudy skies can achieve a high accuracy for vehicle orientation.

An Evaluation of Skylight Polarization Patterns for Navigation

PubMed Central

Ma, Tao; Hu, Xiaoping; Zhang, Lilian; Lian, Junxiang; He, Xiaofeng; Wang, Yujie; Xian, Zhiwen

2015-01-01

Skylight polarization provides a significant navigation cue for certain polarization-sensitive animals. However, the precision of the angle of polarization (AOP) of skylight for vehicle orientation is not clear. An evaluation of AOP must be performed before it is utilized. This paper reports an evaluation of AOP of skylight by measuring the skylight polarization patterns of clear and cloudy skies using a full-sky imaging polarimetry system. AOP measurements of skylight are compared with the pattern calculated by the single-scattering Rayleigh model and these differences are quantified. The relationship between the degree of polarization (DOP) and the deviation of AOP of skylight is thoroughly studied. Based on these, a solar meridian extracted method is presented. The results of experiments reveal that the DOP is a key parameter to indicate the accuracy of AOP measurements, and all the output solar meridian orientations extracted by our method in both clear and cloudy skies can achieve a high accuracy for vehicle orientation. PMID:25763652

The Moon as a Tiny Bright Disc: Insights From Observations in the Planetarium.

PubMed

Carbon, Claus-Christian

2015-01-01

Despite a relatively constant visual angle, the size of the moon appears very variable, mostly depending on elevation and context factors--the so-called moon illusion. As our perceptual experience of the size of the moon is clearly limited to the perceptual sphere of the sky, however, we do not know whether the typical perception of the moon at its zenith reflects a veridical interpretation of its visual angle of only 0.5 degrees. When testing the moon illusion in a large-scale planetarium, we observed two important things: (a) variation in perceptual size was no longer apparent, and (b) the moon looked very much smaller than in any viewing condition in the real sky--even when comparing it at its zenith. A closer inspection of the control console of the planetarium revealed that classic-analog as well as updated-digital planetariums use projections of the moon with strongly increased sizes to compensate for the loss of a natural view of the moon in the artificial dome of the sky.

Evaluation of the night sky quality at El Leoncito and LEO++ in Argentina

NASA Astrophysics Data System (ADS)

Aubé, Martin; García, Beatriz; Fortin, Nicolas; Turcotte, Sara; Mancilla, Alexis; Maya, Javier

2015-08-01

Light pollution is a growing concern at many levels, but especially for the astronomical community. Artificial lighting veil celestial objects and disturbs the measurement of night time atmospheric phenomena. This is what motivates our sky brightness measurement experiment in Argentina. Our goal was to determine the quality of two Argentinian observation sites: LEO++ and El Leoncito. Both sites were candidates to host the Cherenkov Telescope Array (CTA). This project consists of an arrangement of many telescopes that can measure high-energy gamma ray emissions via their Cherenkov radiation produced when entering the earth's atmosphere. Even if the two argentinian sites has been excluded from the final CTA site competition, they are still of great interest for other astronomical projects. Especially the El Leoncito site which already hots the CASLEO astronomical complex. In this presentation, we describe the measurement methods used to determine the sky quality. We compared our results with different renowned astronomical sites (Kitt Peak, Arizona, USA, and Mont-Mégantic, Canada). Amongst our results, we found that LEO++ is a high quality site, however there are a lot of aerosols that can interfere with the measurements. El Leoncito shows very low sky brightness levels, which are optimal for low light level detection.

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 Development of a Virtual McKenna Military Operations in Urban Terrain (MOUT) Site for Command, Control, Communication, Computing, Intelligence, Surveillance, and Reconnaissance (C4ISR) Studies

DTIC Science & Technology

2007-06-01

4.2 Creating the Skybox and Terrain Model .........................................................................7 4.3 Creating New Textures... Skybox and Terrain Model The next step was to build a sky box. Since it already resided in Raven Shield, the creation of the sky box was limited to

Shifts in the potential distribution of Sky Island plant communities in response to climate change

Treesearch

John A. Kupfer; Jeff Balmat; Jacqueline L. Smith

2005-01-01

To examine potential responses of sky island ecosystem pattern to projected climate changes, we used topographic and climatic data to develop a predictive model of plant community distribution in Saguaro National Park East, AZ. Increasing temperatures led to an upslope movement of communities and increased the area of desert scrub at the expense of montane conifer...

Multipurpose Spectroradiometer for Satellite Instrument Calibration and Zenith Sky Remote Sensing Measurements

NASA Technical Reports Server (NTRS)

Heath, Donald F.; Ahmad, Zia

2001-01-01

In the early 1990s a series of surface-based direct sun and zenith sky measurements of total column ozone were made with SBUV/2 flight models and the SSBUV Space Shuttle instrument in Boulder, Colorado which were compared with NOAA Dobson Instrument direct sun observations and TOMS instrument overpass observations of column ozone. These early measurements led to the investigation of the accuracy of derived total column ozone amounts and aerosol optical depths from zenith sky observations. Following the development and availability of radiometrically stable IAD narrow band interference filter and nitrided silicon photodiodes a simple compact multifilter spectroradiometer was developed which can be used as a calibration transfer standard spectroradiometer (CTSS) or as a surface based instrument remote sensing instruments for measurements of total column ozone and aerosol optical depths. The total column ozone derived from zenith sky observations agrees with Dobson direct sun AD double wavelength pair measurements and with TOMS overpass ozone amounts within uncertainties of about 1%. When used as a calibration transfer standard spectroradiometer the multifilter spectroradiometer appears to be capable of establishing instrument radiometric calibration uncertainties of the order of 1% or less relative to national standards laboratory radiometric standards.

Bridging the Radiative Transfer Models for Meteorology and Solar Energy Applications

NASA Astrophysics Data System (ADS)

Xie, Y.; Sengupta, M.

2017-12-01

Radiative transfer models are used to compute solar radiation reaching the earth surface and play an important role in both meteorology and solar energy studies. Therefore, they are designed to meet the needs of specialized applications. For instance, radiative transfer models for meteorology seek to provide more accurate cloudy-sky radiation compared to models used in solar energy that are geared towards accuracy in clear-sky conditions associated with the maximum solar resource. However, models for solar energy applications are often computationally faster, as the complex solution of the radiative transfer equation is parameterized by atmospheric properties that can be acquired from surface- or satellite-based observations. This study introduces the National Renewable Energy Laboratory's (NREL's) recent efforts to combine the advantages of radiative transfer models designed for meteorology and solar energy applictions. A fast all-sky radiation model, FARMS-NIT, was developed to efficiently compute narrowband all-sky irradiances over inclined photovoltaic (PV) panels. This new model utilizes the optical preperties from a solar energy model, SMARTS, to computes surface radiation by considering all possible paths of photon transmission and the relevent scattering and absorption attenuation. For cloudy-sky conditions, cloud bidirectional transmittance functions (BTDFs) are provided by a precomputed lookup table (LUT) by LibRadtran. Our initial results indicate that FARMS-NIT has an accuracy that is similar to LibRadtran, a highly accurate multi-stream model, but is significantly more efficient. The development and validation of this model will be presented.

Upgrade of the NASA 4STAR (Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research) to its Full Science Capability of Sun-Sky-Cloud-Trace Gas Spectrometry in Airborne Science Deployments

NASA Technical Reports Server (NTRS)

Johnson, Roy R.; Russell, P.; Dunagan, S.; Redemann, J.; Shinozuka, Y.; Segal-Rosenheimer, M.; LeBlanc, S.; Flynn, C.; Schmid, B.; Livingston, J.

2014-01-01

The objectives of this task in the AITT (Airborne Instrument Technology Transition) Program are to (1) upgrade the NASA 4STAR (Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research) instrument to its full science capability of measuring (a) direct-beam sun transmission to derive aerosol optical depth spectra, (b) sky radiance vs scattering angle to retrieve aerosol absorption and type (via complex refractive index spectra, shape, and mode-resolved size distribution), (c) zenith radiance for cloud properties, and (d) hyperspectral signals for trace gas retrievals, and (2) demonstrate its suitability for deployment in challenging NASA airborne multiinstrument campaigns. 4STAR combines airborne sun tracking, sky scanning, and zenith pointing with diffraction spectroscopy to improve knowledge of atmospheric constituents and their links to air pollution, radiant energy budgets (hence climate), and remote measurements of Earth's surfaces. Direct beam hyperspectral measurement of optical depth improves retrievals of gas constituents and determination of aerosol properties. Sky scanning enhances retrievals of aerosol type and size distribution. 4STAR measurements are intended to tighten the closure between satellite and ground-based measurements. 4STAR incorporates a modular sun-tracking/sky-scanning optical head with fiber optic signal transmission to rack mounted spectrometers, permitting miniaturization of the external optical head, and future detector evolution. 4STAR test flights, as well as science flights in the 2012-13 TCAP (Two-Column Aerosol Project) and 2013 SEAC4RS (Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys) have demonstrated that the following are essential for 4STAR to achieve its full science potential: (1) Calibration stability for both direct-beam irradiance and sky radiance, (2) Improved light collection and usage, and (3) Improved flight operability and reliability. A particular challenge for the AITT-4STAR project has been conducting it simultaneously with preparations for, and execution of, ARISE (Arctic Radiation - IceBridge Sea&Ice Experiment), a NASA airborne science deployment (unplanned when AITT-4STAR was selected for funding) in which 4STAR will deploy to Thule, Greenland, and Fairbanks, Alaska, on the NASA C- 130. This presentation describes progress to date in accomplishing AITT-4STAR goals, and plans for project completion.

Real-time real-sky dual-conjugate adaptive optics experiment

NASA Astrophysics Data System (ADS)

Knutsson, Per; Owner-Petersen, Mette

2006-06-01

The current status of a real-time real-sky dual-conjugate adaptive optics experiment is presented. This experiment is a follow-up on a lab experiment at Lund Observatory that demonstrated dual-conjugate adaptive optics on a static atmosphere. The setup is to be placed at Lund Observatory. This means that the setup will be available 24h a day and does not have to share time with other instruments. The optical design of the experiment is finalized. A siderostat will be used to track the guide object and all other optical components are placed on an optical table. A small telescope, 35 cm aperture, is used and following this a tip-tilt mirror and two deformable mirrors are placed. The wave-front sensor is a Shack-Hartmann sensor using a SciMeasure Li'l Joe CCD39 camera system. The maximum update rate of the setup will be 0.5 kHz and the control system will be running under Linux. The effective wavelength will be 750 nm. All components in the setup have been acquired and the completion of the setup is underway. Collaborating partners in this project are the Applied Optics Group at National University of Ireland, Galway and the Swedish Defense Research Agency.

Regional and transported aerosols during DRAGON-Japan experiment

NASA Astrophysics Data System (ADS)

Sano, I.; Holben, B. N.; Mukai, S.; Nakata, M.; Nakaguchi, Y.; Sugimoto, N.; Hatakeyama, S.; Nishizawa, T.; Takamura, T.; Takemura, T.; Yonemitsu, M.; Fujito, T.; Schafer, J.; Eck, T. F.; Sorokin, M.; Kenny, P.; Goto, M.; Hiraki, T.; Iguchi, N.; Kouzai, K.; KUJI, M.; Muramatsu, K.; Okada, Y.; Sadanaga, Y.; Tohno, S.; Toyazaki, Y.; Yamamoto, K.

2013-12-01

Aerosol properties over Japan have been monitored by AERONET sun / sky photometers since 2000. These measurements provides us with long term information of local aerosols, which are influenced by transported aerosols, such as Asian dusts or anthropogenic pollutants due to rapid increasing of energy consumption in Asian countries. A new aerosol monitoring experiment, Distributed Regional Aerosol Gridded Observation Networks (DRAGON) - Japan is operated in spring of 2012. The main instrument of DRAGON network is AERONET sun/sky radiometers. Some of them are sparsely set along the Japanese coast and some others make a dense network in Osaka, which is the second-largest city in Japan and famous for manufacturing town. Several 2ch NIES-LIDAR systems are also co-located with AERONET instrument to monitor Asian dusts throughout the campaign. The objects of Dragon-Japan are to characterize local aerosols as well as transported ones from the continent of China, and to acquire the detailed aerosol information for validating satellite data with high resolved spatial scale. This work presents the comprehensive results of aerosol properties with respect to regional- and/or transported- scale during DRAGON-Japan experiments.

Searching for bumps and ellipses on the ground and in the sky: no advantage for the ground plane.

PubMed

Jóhannesson, Omar I; Sigurdardottir, Kristín Ósk; Kristjánsson, Arni

2013-11-01

A staple of modern theories of vision is that the visual system has evolved to perceive cues containing the most predictive information about the layout of the environment. This entails the prediction that - other things being equal - visual performance in a familiar setting should be superior to performance in an unfamiliar one. Visual performance should therefore be better on the familiar ground plane compared to an implied sky or wall plane. We tested this comparing visual search for stimuli presented in an implied ground plane with search on a 180° rotated search display so that the stimuli appeared in an implied "sky" plane, and with search in a random layout implying no depth. This was tested for stimuli with, or without, curvature discontinuities, that have previously been shown to be strong cues for shape analysis. Surprisingly, no advantage of the ground plane over the sky plane was observed, while a strong effect of layout regularity was seen. Similarly, in experiment 2 there was little effect of placing the stimuli on an implied wall plane compared to the ground or the sky. The results are not explained by assuming that curvature discontinuities are such strong cues that they overshadow any effect of depth-plane, since there was a strong effect of regular versus random layout, which should also have disappeared under this account. The results argue instead for a very strong effect of layout regularity, unrelated to environmental regularities in evolutionary history, since there was no ground-plane benefit. Copyright © 2013 Elsevier B.V. All rights reserved.

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.

Can We Build an Open-Science Model to Fund Young, Risky, Blue-Sky Research? First Insights into Funding Geoscientists Via Thinkable.Org

NASA Astrophysics Data System (ADS)

McNeil, B.

2014-12-01

Some of the biggest discoveries and advances in geoscience research have come from purely curiosity-driven, blue-sky research. Marine biologist Osamu Shimomura's discovery of Green-Fluorecent Protein (GFP) in the 1960s during his postdoc is just one example, which came about through his interest and pursuit of how certain jellyfish bioluminescence. His discovery would eventually revolutionise medicine, culminating in a Nobel Prize in Chemistry in 2008. Despite the known importance of "blue-sky" research that doesn't have immediate commercial or social applications, it continues to struggle for funding from both government and industry. Success rates for young scientists also continue to decline within the government competitive granting models due to the importance of track records, yet history tells us that young scientists tend to come up with science's greatest discoveries. The digital age however, gives us a new opportunity to create an alternative and sustainable funding model for young, risky, blue-sky science that tends not to be supported by governments and industry anymore. Here I will discuss how new digital platforms empower researchers and organisations to showcase their research using video, allowing wider community engagment and funding that can be used to directly support young, risky, blue-sky research that is so important to the future of science. I will then talk about recent experience with this model from some ocean researchers who used a new platform called thinkable.org to showcase and raise funding via the public.

Kinesthetic Astronomy: Significant Upgrades to the Sky Time Lesson that Support Student Learning

NASA Astrophysics Data System (ADS)

Morrow, C. A.; Zawaski, M.

2004-12-01

This paper will report on a significant upgrade to the first in a series of innovative, experiential lessons we call Kinesthetic Astronomy. The Sky Time lesson reconnects students with the astronomical meaning of the day, year, and seasons. Like all Kinesthetic Astronomy lessons, it teaches basic astronomical concepts through choreographed bodily movements and positions that provide educational sensory experiences. They are intended for sixth graders up through adult learners in both formal and informal educational settings. They emphasize astronomical concepts and phenomenon that people can readily encounter in their "everyday" lives such as time, seasons, and sky motions of the Sun, Moon, stars, and planets. Kinesthetic Astronomy lesson plans are fully aligned with national science education standards, both in content and instructional practice. Our lessons offer a complete learning cycle with written assessment opportunities now embedded throughout the lesson. We have substantially strengthened the written assessment options for the Sky Time lesson to help students translate their kinesthetic and visual learning into the verbal-linguistic and mathematical-logical realms of expression. Field testing with non-science undergraduates, middle school science teachers and students, Junior Girl Scouts, museum education staff, and outdoor educators has been providing evidence that Kinesthetic Astronomy techniques allow learners to achieve a good grasp of concepts that are much more difficult to learn in more conventional ways such as via textbooks or even computer animation. Field testing of the Sky Time lesson has also led us to significant changes from the previous version to support student learning. We will report on the nature of these changes.

Planck 2015 results. X. Diffuse component separation: Foreground maps

NASA Astrophysics Data System (ADS)

Planck Collaboration; Adam, R.; Ade, P. A. R.; Aghanim, N.; Alves, M. I. R.; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartlett, J. G.; Bartolo, N.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bock, J. J.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Boulanger, F.; Bucher, M.; Burigana, C.; Butler, R. C.; Calabrese, E.; Cardoso, J.-F.; Catalano, A.; Challinor, A.; Chamballu, A.; Chary, R.-R.; Chiang, H. C.; Christensen, P. R.; Clements, D. L.; Colombi, S.; Colombo, L. P. L.; Combet, C.; Couchot, F.; Coulais, A.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Désert, F.-X.; Dickinson, C.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Falgarone, E.; Fergusson, J.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Frejsel, A.; Galeotta, S.; Galli, S.; Ganga, K.; Ghosh, T.; Giard, M.; Giraud-Héraud, Y.; Gjerløw, E.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J. E.; Hansen, F. K.; Hanson, D.; Harrison, D. L.; Helou, G.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.; Huffenberger, K. M.; Hurier, G.; Jaffe, A. H.; Jaffe, T. R.; Jones, W. C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Lattanzi, M.; Lawrence, C. R.; Le Jeune, M.; Leahy, J. P.; Leonardi, R.; Lesgourgues, J.; Levrier, F.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maggio, G.; Maino, D.; Mandolesi, N.; Mangilli, A.; Maris, M.; Marshall, D. J.; Martin, P. G.; Martínez-González, E.; Masi, S.; Matarrese, S.; McGehee, P.; Meinhold, P. R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; Orlando, E.; Oxborrow, C. A.; Paci, F.; Pagano, L.; Pajot, F.; Paladini, R.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Pearson, T. J.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pettorino, V.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Pratt, G. W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Reach, W. T.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rossetti, M.; Roudier, G.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Santos, D.; Savelainen, M.; Savini, G.; Scott, D.; Seiffert, M. D.; Shellard, E. P. S.; Spencer, L. D.; Stolyarov, V.; Stompor, R.; Strong, A. W.; Sudiwala, R.; Sunyaev, R.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, F.; Vielva, P.; Villa, F.; Wade, L. A.; Wandelt, B. D.; Wehus, I. K.; Wilkinson, A.; Yvon, D.; Zacchei, A.; Zonca, A.

2016-09-01

Planck has mapped the microwave sky in temperature over nine frequency bands between 30 and 857 GHz and in polarization over seven frequency bands between 30 and 353 GHz in polarization. In this paper we consider the problem of diffuse astrophysical component separation, and process these maps within a Bayesian framework to derive an internally consistent set of full-sky astrophysical component maps. Component separation dedicated to cosmic microwave background (CMB) reconstruction is described in a companion paper. For the temperature analysis, we combine the Planck observations with the 9-yr Wilkinson Microwave Anisotropy Probe (WMAP) sky maps and the Haslam et al. 408 MHz map, to derive a joint model of CMB, synchrotron, free-free, spinning dust, CO, line emission in the 94 and 100 GHz channels, and thermal dust emission. Full-sky maps are provided for each component, with an angular resolution varying between 7.´5 and 1deg. Global parameters (monopoles, dipoles, relative calibration, and bandpass errors) are fitted jointly with the sky model, and best-fit values are tabulated. For polarization, the model includes CMB, synchrotron, and thermal dust emission. These models provide excellent fits to the observed data, with rms temperature residuals smaller than 4μK over 93% of the sky for all Planck frequencies up to 353 GHz, and fractional errors smaller than 1% in the remaining 7% of the sky. The main limitations of the temperature model at the lower frequencies are internal degeneracies among the spinning dust, free-free, and synchrotron components; additional observations from external low-frequency experiments will be essential to break these degeneracies. The main limitations of the temperature model at the higher frequencies are uncertainties in the 545 and 857 GHz calibration and zero-points. For polarization, the main outstanding issues are instrumental systematics in the 100-353 GHz bands on large angular scales in the form of temperature-to-polarization leakage, uncertainties in the analogue-to-digital conversion, and corrections for the very long time constant of the bolometer detectors, all of which are expected to improve in the near future.

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

Adam, R.; Ade, P. A. R.; Aghanim, N.

We report that Planck has mapped the microwave sky in temperature over nine frequency bands between 30 and 857 GHz and in polarization over seven frequency bands between 30 and 353 GHz in polarization. In this paper we consider the problem of diffuse astrophysical component separation, and process these maps within a Bayesian framework to derive an internally consistent set of full-sky astrophysical component maps. Component separation dedicated to cosmic microwave background (CMB) reconstruction is described in a companion paper. For the temperature analysis, we combine the Planck observations with the 9-yr Wilkinson Microwave Anisotropy Probe (WMAP) sky maps andmore » the Haslam et al. 408 MHz map, to derive a joint model of CMB, synchrotron, free-free, spinning dust, CO, line emission in the 94 and 100 GHz channels, and thermal dust emission. Full-sky maps are provided for each component, with an angular resolution varying between 7.5 and 1deg. Global parameters (monopoles, dipoles, relative calibration, and bandpass errors) are fitted jointly with the sky model, and best-fit values are tabulated. For polarization, the model includes CMB, synchrotron, and thermal dust emission. These models provide excellent fits to the observed data, with rms temperature residuals smaller than 4μK over 93% of the sky for all Planck frequencies up to 353 GHz, and fractional errors smaller than 1% in the remaining 7% of the sky. The main limitations of the temperature model at the lower frequencies are internal degeneracies among the spinning dust, free-free, and synchrotron components; additional observations from external low-frequency experiments will be essential to break these degeneracies. The main limitations of the temperature model at the higher frequencies are uncertainties in the 545 and 857 GHz calibration and zero-points. For polarization, the main outstanding issues are instrumental systematics in the 100–353 GHz bands on large angular scales in the form of temperature-to-polarization leakage, uncertainties in the analogue-to-digital conversion, and corrections for the very long time constant of the bolometer detectors, all of which are expected to improve in the near future.« less

Planck 2015 results: X. Diffuse component separation: Foreground maps

DOE PAGES

Adam, R.; Ade, P. A. R.; Aghanim, N.; ...

2016-09-20

We report that Planck has mapped the microwave sky in temperature over nine frequency bands between 30 and 857 GHz and in polarization over seven frequency bands between 30 and 353 GHz in polarization. In this paper we consider the problem of diffuse astrophysical component separation, and process these maps within a Bayesian framework to derive an internally consistent set of full-sky astrophysical component maps. Component separation dedicated to cosmic microwave background (CMB) reconstruction is described in a companion paper. For the temperature analysis, we combine the Planck observations with the 9-yr Wilkinson Microwave Anisotropy Probe (WMAP) sky maps andmore » the Haslam et al. 408 MHz map, to derive a joint model of CMB, synchrotron, free-free, spinning dust, CO, line emission in the 94 and 100 GHz channels, and thermal dust emission. Full-sky maps are provided for each component, with an angular resolution varying between 7.5 and 1deg. Global parameters (monopoles, dipoles, relative calibration, and bandpass errors) are fitted jointly with the sky model, and best-fit values are tabulated. For polarization, the model includes CMB, synchrotron, and thermal dust emission. These models provide excellent fits to the observed data, with rms temperature residuals smaller than 4μK over 93% of the sky for all Planck frequencies up to 353 GHz, and fractional errors smaller than 1% in the remaining 7% of the sky. The main limitations of the temperature model at the lower frequencies are internal degeneracies among the spinning dust, free-free, and synchrotron components; additional observations from external low-frequency experiments will be essential to break these degeneracies. The main limitations of the temperature model at the higher frequencies are uncertainties in the 545 and 857 GHz calibration and zero-points. For polarization, the main outstanding issues are instrumental systematics in the 100–353 GHz bands on large angular scales in the form of temperature-to-polarization leakage, uncertainties in the analogue-to-digital conversion, and corrections for the very long time constant of the bolometer detectors, all of which are expected to improve in the near future.« less

Validation of a spectral correction procedure for sun and sky reflections in above-water reflectance measurements.

PubMed

Groetsch, Philipp M M; Gege, Peter; Simis, Stefan G H; Eleveld, Marieke A; Peters, Steef W M

2017-08-07

A three-component reflectance model (3C) is applied to above-water radiometric measurements to derive remote-sensing reflectance Rrs (λ). 3C provides a spectrally resolved offset Δ(λ) to correct for residual sun and sky radiance (Rayleigh- and aerosol-scattered) reflections on the water surface that were not represented by sky radiance measurements. 3C is validated with a data set of matching above- and below-water radiometric measurements collected in the Baltic Sea, and compared against a scalar offset correction Δ. Correction with Δ(λ) instead of Δ consistently reduced the (mean normalized root-mean-square) deviation between Rrs (λ) and reference reflectances to comparable levels for clear (Δ: 14.3 ± 2.5 %, Δ(λ): 8.2 ± 1.7 %), partly clouded (Δ: 15.4 ± 2.1 %, Δ(λ): 6.5 ± 1.4 %), and completely overcast (Δ: 10.8 ± 1.7 %, Δ(λ): 6.3 ± 1.8 %) sky conditions. The improvement was most pronounced under inhomogeneous sky conditions when measurements of sky radiance tend to be less representative of surface-reflected radiance. Accounting for both sun glint and sky reflections also relaxes constraints on measurement geometry, which was demonstrated based on a semi-continuous daytime data set recorded in a eutrophic freshwater lake in the Netherlands. Rrs (λ) that were derived throughout the day varied spectrally by less than 2 % relative standard deviation. Implications on measurement protocols are discussed. An open source software library for processing reflectance measurements was developed and is made publicly available.

The sky blue method as a screening test to detect misplacement of percutaneous endoscopic gastrostomy tube at exchange.

PubMed

Suzuki, Yutaka; Urashima, Mitsuyoshi; Yoshida, Hideki; Iwase, Tsuyoshi; Kura, Toshiroh; Imazato, Shin; Kudo, Michiaki; Ohta, Tomoyuki; Mizuhara, Akihiro; Tamamori, Yutaka; Muramatsu, Hirohito; Nishiguchi, Yukio; Nishiyama, Yorihiro; Takahashi, Mikako; Nishiwaki, Shinji; Matsumoto, Masami; Goshi, Satoshi; Sakamoto, Shigeo; Uchida, Nobuyuki; Ijima, Masashi; Ogawa, Tetsushi; Shimazaki, Makoto; Takei, Shinichi; Kimura, Chikou; Yamashita, Satoyoshi; Endo, Takao; Nakahori, Masato; Itoh, Akihiko; Kusakabe, Toshiro; Ishizuka, Izumi; Iiri, Takao; Fukasawa, Shingo; Arimoto, Yukitsugu; Kajitani, Nobuaki; Ishida, Kazuhiko; Onishi, Koji; Taira, Akihiko; Kobayashi, Makoto; Itano, Yasuto; Kobuke, Toshiya

2009-01-01

During tube exchange for percutaneous endoscopic gastrostomy (PEG), a misplaced tube can cause peritonitis and death. Thus, endoscopic or radiologic observation is required at tube exchange to make sure the tube is placed correctly. However, these procedures cost extensive time and money to perform in all patients at the time of tube exchange. Therefore, we developed the "sky blue method" as a screening test to detect misplacement of the PEG tube during tube exchange. First, sky blue solution consisting of indigocarmine diluted with saline was injected into the gastric space via the old PEG tube just before the tube exchange. Next, the tube was exchanged using a standard method. Then, we checked whether the sky blue solution could be collected through the new tube or not. Finally, we confirmed correct placement of the tube by endoscopic or radiologic observation for all patients. A total of 961 patients were enrolled. Each tube exchange took 1 to 3 minutes, and there were no adverse effects. Four patients experienced a misplaced tube, all of which were detectable with the sky blue method. Diagnostic parameters of the sky blue method were as follows: sensitivity, 94% (95%CI: 92-95%); specificity, 100% (95%CI: 40-100%); positive predictive value, 100% (95%CI: 100-100%); negative predictive value, 6% (95%CI: 2-16%). These results suggest that the number of endoscopic or radiologic observations to confirm correct replacement of the PEG tube may be reduced to one fifteenth using the sky blue method.

CONCAM's Fuzzy-Logic All-Sky Star Recognition Algorithm

NASA Astrophysics Data System (ADS)

Shamir, L.; Nemiroff, R. J.

2004-05-01

One of the purposes of the global Night Sky Live (NSL) network of fisheye CONtinuous CAMeras (CONCAMs) is to monitor and archive the entire bright night sky, track stellar variability, and search for transients. The high quality of raw CONCAM data allows automation of stellar object recognition, although distortions of the fisheye lens and frequent slight shifts in CONCAM orientations can make even this seemingly simple task formidable. To meet this challenge, a fuzzy logic based algorithm has been developed that transforms (x,y) image coordinates in the CCD frame into fuzzy right ascension and declination coordinates for use in matching with star catalogs. Using a training set of reference stars, the algorithm statically builds the fuzzy logic model. At runtime, the algorithm searches for peaks, and then applies the fuzzy logic model to perform the coordinate transformation before choosing the optimal star catalog match. The present fuzzy-logic algorithm works much better than our first generation, straightforward coordinate transformation formula. Following this essential step, algorithms dealing with the higher level data products can then provide a stream of photometry for a few hundred stellar objects visible in the night sky. Accurate photometry further enables the computation of all-sky maps of skyglow and opacity, as well as a search for uncataloged transients. All information is stored in XML-like tagged ASCII files that are instantly copied to the public domain and available at http://NightSkyLive.net. Currently, the NSL software detects stars and creates all-sky image files from eight different locations around the globe every 3 minutes and 56 seconds.

Effective cloud optical depth and enhancement effects for broken liquid water clouds in Valencia (Spain)

NASA Astrophysics Data System (ADS)

Marín, M. J.; Serrano, D.; Utrillas, M. P.; Núñez, M.; Martínez-Lozano, J. A.

2017-10-01

Partly cloudy skies with liquid water clouds have been analysed, founding that it is essential to distinguish data if the Sun is obstructed or not by clouds. Both cases can be separated considering simultaneously the Cloud Modification Factor (CMF) and the clearness index (kt). For partly cloudy skies and the Sun obstructed the effective cloud optical depth (τ) has been obtained by the minimization method for overcast skies. This method was previously developed by the authors but, in this case, taking into account partial cloud cover. This study has been conducted for the years 2011-2015 with the multiple scattering model SBDART and irradiance measurements for the UV Erythemal Radiation (UVER) and the broadband ranges. Afterwards a statistical analysis of τ has shown that the maximum value is much lower than for overcast skies and there is more discrepancy between the two spectral ranges regarding the results for overcast skies. In order to validate these results the effective cloud optical depth has been correlated with several transmission factors, giving similar fit parameters to those obtained for overcast skies except for the clearness index in the UVER range. As our method is not applicable for partly cloudy skies with the visible Sun, the enhancement of radiation caused by clouds when the Sun is visible has been studied. Results show that the average enhancement CMF values are the same for both ranges although enhancement is more frequent for low cloud cover in the UVER and medium-high cloud cover in the broadband range and it does not depend on the solar zenith angle.

Carbon monoxide column retrieval for clear-sky and cloudy atmospheres: a full-mission data set from SCIAMACHY 2.3 µm reflectance measurements

NASA Astrophysics Data System (ADS)

Borsdorff, Tobias; aan de Brugh, Joost; Hu, Haili; Nédélec, Philippe; Aben, Ilse; Landgraf, Jochen

2017-05-01

We discuss the retrieval of carbon monoxide (CO) vertical column densities from clear-sky and cloud contaminated 2311-2338 nm reflectance spectra measured by the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) from January 2003 until the end of the mission in April 2012. These data were processed with the Shortwave Infrared CO Retrieval algorithm (SICOR) that we developed for the operational data processing of the Tropospheric Monitoring Instrument (TROPOMI) that will be launched on ESA's Sentinel-5 Precursor (S5P) mission. This study complements previous work that was limited to clear-sky observations over land. Over the oceans, CO is estimated from cloudy-sky measurements only, which is an important addition to the SCIAMACHY clear-sky CO data set as shown by NDACC and TCCON measurements at coastal sites. For Ny-Ålesund, Lauder, Mauna Loa and Reunion, a validation of SCIAMACHY clear-sky retrievals is not meaningful because of the high retrieval noise and the few collocations at these sites. The situation improves significantly when considering cloudy-sky observations, where we find a low mean bias b = ±6. 0 ppb and a strong correlation between the validation and the SCIAMACHY results with a mean Pearson correlation coefficient r = 0. 7. Also for land observations, cloudy-sky CO retrievals present an interesting complement to the clear-sky data set. For example, at the cities Tehran and Beijing the agreement of SCIAMACHY clear-sky CO observations with MOZAIC/IAGOS airborne measurements is poor with a mean bias of b = 171. 2 ppb and 57.9 ppb because of local CO pollution, which cannot be captured by SCIAMACHY. For cloudy-sky retrievals, the validation improves significantly. Here the retrieved column is mainly sensitive to CO above the cloud and so not affected by the strong local surface emissions. Adjusting the MOZAIC/IAGOS measurements to the vertical sensitivity of the retrieval, the mean bias adds up to b = 52. 3 ppb and 5.0 ppb for Tehran and Beijing. At the less urbanised region around the airport Windhoek, local CO pollution is less prominent and so MOZAIC/IAGOS measurements agree well with SCIAMACHY clear-sky retrievals with a mean bias of b = 15. 5 ppb, but can be even further improved for cloudy SCIAMACHY observations with a mean bias of b = 0. 2 ppb. Overall the cloudy-sky CO retrievals from SCIAMACHY short-wave infrared measurements present a major extension of the clear-sky-only data set, which more than triples the amount of data and adds unique observations over the oceans. Moreover, the study represents the first application of the S5P algorithm for operational CO data processing on cloudy observations prior to the launch of the S5P mission.

Cosmic Balloons

ERIC Educational Resources Information Center

El Abed, Mohamed

2014-01-01

A team of French high-school students sent a weather balloon into the upper atmosphere to recreate Viktor Hess's historical experiment that demonstrated the existence of ionizing radiation from the sky--later called cosmic radiation. This discovery earned him the Nobel Prize for Physics in 1936.

Database of extended radiation maps and its access system

NASA Astrophysics Data System (ADS)

Verkhodanov, O. V.; Naiden, Ya. V.; Chernenkov, V. N.; Verkhodanova, N. V.

2014-01-01

We describe the architecture of the developed computing web server http://cmb.sao.ru allowing to synthesize the maps of extended radiation on the full sphere from the spherical harmonics in the GLESP pixelization grid, smooth them with the power beam pattern with various angular resolutions in the multipole space, and identify regions of the sky with given coordinates. We describe the server access and administration systems as well as the technique constructing the sky region maps, organized in Python in the Django web-application development framework.

An on-line interface for integrated modeling of wildlife, climate, and society for strategic planning for the Sky Islands

Treesearch

Barron J. Orr; Wolfgang Grunberg; Amanda B. Cockerham; Anne Y. Thwaits; Heather S. Severson; Noah M. D. Lerman; Rachel M. Miller; Michael Haseltine; Barbara J. Morehouse; Jonathan T. Overpeck; Stephen R. Yool; Thomas W. Swetnam; Gary L. Christopherson

2005-01-01

The demand for strategic planning tools that account for climate and human influences on wildfire hazard is growing. In response, the University of Arizona, through an EPA STAR Grant has undertaken interdisciplinary research to characterize the human and climate dimensions of wildfire. The resulting Fire-Climate-Society (FCS-1) prototype model developed for Sky Islands...

Spectral performance of Square Kilometre Array Antennas - II. Calibration performance

NASA Astrophysics Data System (ADS)

Trott, Cathryn M.; de Lera Acedo, Eloy; Wayth, Randall B.; Fagnoni, Nicolas; Sutinjo, Adrian T.; Wakley, Brett; Punzalan, Chris Ivan B.

2017-09-01

We test the bandpass smoothness performance of two prototype Square Kilometre Array (SKA) SKA1-Low log-periodic dipole antennas, SKALA2 and SKALA3 ('SKA Log-periodic Antenna'), and the current dipole from the Murchison Widefield Array (MWA) precursor telescope. Throughout this paper, we refer to the output complex-valued voltage response of an antenna when connected to a low-noise amplifier, as the dipole bandpass. In Paper I, the bandpass spectral response of the log-periodic antenna being developed for the SKA1-Low was estimated using numerical electromagnetic simulations and analysed using low-order polynomial fittings, and it was compared with the HERA antenna against the delay spectrum metric. In this work, realistic simulations of the SKA1-Low instrument, including frequency-dependent primary beam shapes and array configuration, are used with a weighted least-squares polynomial estimator to assess the ability of a given prototype antenna to perform the SKA Epoch of Reionisation (EoR) statistical experiments. This work complements the ideal estimator tolerances computed for the proposed EoR science experiments in Trott & Wayth, with the realized performance of an optimal and standard estimation (calibration) procedure. With a sufficient sky calibration model at higher frequencies, all antennas have bandpasses that are sufficiently smooth to meet the tolerances described in Trott & Wayth to perform the EoR statistical experiments, and these are primarily limited by an adequate sky calibration model and the thermal noise level in the calibration data. At frequencies of the Cosmic Dawn, which is of principal interest to SKA as one of the first next-generation telescopes capable of accessing higher redshifts, the MWA dipole and SKALA3 antenna have adequate performance, while the SKALA2 design will impede the ability to explore this era.

MOXE: An X-ray all-sky monitor for Soviet Spectrum-X-Gamma Mission

NASA Technical Reports Server (NTRS)

Priedhorsky, W.; Fenimore, E. E.; Moss, C. E.; Kelley, R. L.; Holt, S. S.

1989-01-01

A Monitoring Monitoring X-Ray Equipment (MOXE) is being developed for the Soviet Spectrum-X-Gamma Mission. MOXE is an X-ray all-sky monitor based on array of pinhole cameras, to be provided via a collaboration between Goddard Space Flight Center and Los Alamos National Laboratory. The objectives are to alert other observers on Spectrum-X-Gamma and other platforms of interesting transient activity, and to synoptically monitor the X-ray sky and study long-term changes in X-ray binaries. MOXE will be sensitive to sources as faint as 2 milliCrab (5 sigma) in 1 day, and cover the 2 to 20 KeV band.

The Citizen Sky Planetarium Trailer

NASA Astrophysics Data System (ADS)

Turner, Rebecca; Price, A.; Wyatt, R.

2011-05-01

Citizen Sky is a multi-year, citizen science project focusing on the bright variable star, epsilon Aurigae. We have developed a six-minute video presentation describing eclipsing binary stars, light curves, and the Citizen Sky project. Designed like a short movie trailer, the video can be shown at planetariums before their regular, feature shows or integrated into a longer presentation. The trailer is available in a wide range of formats for viewing on laptops all the way up to state-of-the-art planetariums. The show is narrated by Timothy Ferris and was produced by the Morrison Planetarium and Visualization Studio at the California Academy of Sciences. This project has been made possible by the National Science Foundation.

The Citizen Sky Planetarium Trailer

NASA Astrophysics Data System (ADS)

Turner, R.; Price, A.; Wyatt, R.

2012-06-01

(Abstract only) Citizen Sky is a multi-year, citizen science project focusing on the bright variable star e Aurigae. We have developed a six-minute video presentation describing eclipsing binary stars, light curves, and the Citizen Sky project. Designed like a short movie trailer, the video can be shown at planetariums before their regular, feature shows or integrated into a longer presentation. The trailer is available in a wide range of formats for viewing on laptops all the way up to state-of-the-art planetariums. The show is narrated by Timothy Ferris and was produced by the Morrison Planetarium and Visualization Studio at the California Academy of Sciences. This project has been made possible by the National Science Foundation.

A Proposal submitted to Biological Systems Science Division of DOE requesting Participant Support Costs for the Fifth International Conference on Polar and Alpine Microbiology

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

Priscu, John

The 5th International Conference on Polar and Alpine Microbiology (PAM5) was held in Big Sky, Montana (USA) from 8-12 September 2013. This meeting is a continuation of the highly successful meetings previously held in Rovaniemi, Finland (2004), Innsbruck, Austria (2006), Banff, Canada (2008) and Ljubljana, Slovenia (2011), which brought together leading international researchers and students in this field. The objectives of the Big Sky meeting were to bring together scientists, students and professionals to discuss all aspects of cold-adapted microorganisms and the roles they play in polar and alpine environments, to understand the role of these organisms in our searchmore » for life on other icy worlds, to address recent developments, and to exchange ideas and experiences on an international scale. The conference provided a multi-disciplinary forum to explore emerging areas in the field and as always, will have a wealth of opportunities for the exchange of ideas and building of collaborations. Funds were requested to help defray registration fees and travel costs of 13 early career scientists. Distribution of the funds were based on the quality of the abstracts submitted.« less

A speeded-up saliency region-based contrast detection method for small targets

NASA Astrophysics Data System (ADS)

Li, Zhengjie; Zhang, Haiying; Bai, Jiaojiao; Zhou, Zhongjun; Zheng, Huihuang

2018-04-01

To cope with the rapid development of the real applications for infrared small targets, the researchers have tried their best to pursue more robust detection methods. At present, the contrast measure-based method has become a promising research branch. Following the framework, in this paper, a speeded-up contrast measure scheme is proposed based on the saliency detection and density clustering. First, the saliency region is segmented by saliency detection method, and then, the Multi-scale contrast calculation is carried out on it instead of traversing the whole image. Second, the target with a certain "integrity" property in spatial is exploited to distinguish the target from the isolated noises by density clustering. Finally, the targets are detected by a self-adaptation threshold. Compared with time-consuming MPCM (Multiscale Patch Contrast Map), the time cost of the speeded-up version is within a few seconds. Additional, due to the use of "clustering segmentation", the false alarm caused by heavy noises can be restrained to a lower level. The experiments show that our method has a satisfied FASR (False alarm suppression ratio) and real-time performance compared with the state-of-art algorithms no matter in cloudy sky or sea-sky background.

Enabling Astronony Research in High Schools with the START Collaboratory

NASA Astrophysics Data System (ADS)

Greenberg, G. J.; Pennypacker, C. R.

2005-12-01

The START Collaboratory is a three-year, NSF funded project to create a Web-based national astronomy research collaboratory for high school students that will bring authentic scientific research to classrooms across the country. The project brings together the resources and experience of Hands-On Universe at the University of California at Berkeley, the Sloan Digital Sky Survey / National Virtual Observatory at Johns Hopkins University and the Northwestern University Collaboratory Project. The START Collaboratory seamlessly integrates access to gigabytes of searchable data and images from the Sloan Digital Sky Survey and the NVO into Web-based research notebooks and research reports that can be shared and discussed online. Requests for observations can be made through the START Telescope Request Broker. These observations can be viewed with the START Web Visualization Tool for visualization and measurement of FITS files. The project has developed a set of research scenarios to introduce students to the resources and tools available through the START Collaboratory, and to provide a model for network-based collaboration that engages students, teachers and professional scientists. Great attention has been paid to ensuring that the research scenarios result in accurate and authentic research products that are of real interest to working astronomers. In this panel presentation, we will describe the educational benefits and opportunities being seen in pilot testing with teachers and students, and in preparations for a teacher professional development project with the Adler Planetarium.

Obituary: William L. Kraushaar, 1920-2008

NASA Astrophysics Data System (ADS)

Clark, George W.

2009-01-01

Professor William L. Kraushaar, a former MIT physics professor and a pioneer in the field of high-energy astronomy, died 21 March 2008 of complications from Parkinson's disease. He was 87. Kraushaar received his bachelor's degree from Lafayette College in 1942. During World War II he worked at the National Bureau of Standards on projects that included development of the proximity fuse for artillery shells. After the war he earned his doctorate at Cornell University. In 1949 Kraushaar was appointed research associate at MIT, where he made the first measurements of the mean life of the pi meson at the MIT electron synchrotron. Over the next fifteen years he rose through the faculty ranks, becoming a full professor before leaving MIT for the University of Wisconsin at Madison in 1965. In 1957 Kraushaar began a decade-long effort to map the sky in the "light" of cosmic gamma rays. Their detection promised to open new ways to investigate high-energy processes in the universe. Initial balloon-borne experiments failed due to background gamma rays generated in the residual atmosphere above the highest attainable altitudes. In 1958, Kraushaar seized a new opportunity for experiments above the atmosphere. Working with Professor George Clark, he directed the development in the MIT Laboratory for Nuclear Science of a gamma-ray detector for a satellite experiment that was launched in April 1961 as Explorer 11. It registered 31 events with the electronic signatures of cosmic gamma rays with energies greater than 50 MeV. Kraushaar then initiated a second and more refined experiment to be carried on OSO 3. In this project Kraushaar and Clark were joined by Gordon Garmire, a former student of Kraushaar. The OSO 3 experiment, launched in March of 1967, registered 621 cosmic gamma-ray events. It yielded the first all-sky map of high-energy cosmic gamma rays showing a concentration of gamma rays from directions in the Milky Way where gamma-ray producing interactions of charged cosmic rays with interstellar matter are most abundant. It also demonstrated the existence of extra-galactic gamma-ray sources that have since been identified as giant black holes at the centers of distant galaxies. The OSO 3 experiment opened the field of high-energy gamma-ray astronomy, which has become one of the most active areas of space research. Upon his move to Wisconsin, Kraushaar established a research group in the new area of X-ray astronomy. Using instruments flown on "sounding" rockets, he and his colleagues produced the first all-sky map of low-energy X rays that revealed the spatial distribution of million-degree interstellar gas. They extended these results in several satellite experiments. Kraushaar was appointed the Max Mason Professor of Physics in 1980. Kraushaar was a fellow of the American Physical Society, and a member of the American Astronomical Society, the International Astronomical Union, the National Academy of Sciences, and the American Academy of Arts and Sciences. He received Fulbright and Guggenheim fellowships and the Senior Scientist Award of the Humboldt Foundation. He served on numerous advisory committees of the National Academy of Sciences and NASA. Kraushaar co-authored with Professor Uno Ingard a college text, Introduction to Mechanics, Matter, and Waves. After his retirement, Kraushaar moved to Maine where he resided in Scarborough with summers at his cabin in Denmark, Maine. He is survived by his wife, the former Elizabeth Rodgers, and by three children from his first marriage. This obituary is based on an article that appeared in the 2 April 2008 edition of MIT Tech Talk.

David Kasner, MD, and the Road to Pars Plana Vitrectomy

PubMed Central

Blodi, Christopher F.

2016-01-01

David Kasner, MD (1927–2001), used his extensive dissections of eye bank eyes and experiences in teaching cataract surgery to resident physicians to realize that excision of vitreous when present in the anterior chamber of eyes undergoing cataract surgery was preferable to prior intraoperative procedures. Noting that eyes tolerated his maneuvers, he then performed planned subtotal open-sky vitrectomies; first on a traumatized eye in 1961, then on two eyes of patients with amyloidosis (1966–1967). The success of these operations was noted by others, most particularly Robert Machemer, MD. Kasner’s work directly led to further surgical developments, including closed pars plana vitrectomy. PMID:27660504

Calibrating CHIME: a new radio interferometer to probe dark energy

NASA Astrophysics Data System (ADS)

Newburgh, Laura B.; Addison, Graeme E.; Amiri, Mandana; Bandura, Kevin; Bond, J. Richard; Connor, Liam; Cliche, Jean-François; Davis, Greg; Deng, Meiling; Denman, Nolan; Dobbs, Matt; Fandino, Mateus; Fong, Heather; Gibbs, Kenneth; Gilbert, Adam; Griffin, Elizabeth; Halpern, Mark; Hanna, David; Hincks, Adam D.; Hinshaw, Gary; Höfer, Carolin; Klages, Peter; Landecker, Tom; Masui, Kiyoshi; Parra, Juan Mena; Pen, Ue-Li; Peterson, Jeff; Recnik, Andre; Shaw, J. Richard; Sigurdson, Kris; Sitwell, Micheal; Smecher, Graeme; Smegal, Rick; Vanderlinde, Keith; Wiebe, Don

2014-07-01

The Canadian Hydrogen Intensity Mapping Experiment (CHIME) is a transit interferometer currently being built at the Dominion Radio Astrophysical Observatory (DRAO) in Penticton, BC, Canada. We will use CHIME to map neutral hydrogen in the frequency range 400 { 800MHz over half of the sky, producing a measurement of baryon acoustic oscillations (BAO) at redshifts between 0.8 { 2.5 to probe dark energy. We have deployed a pathfinder version of CHIME that will yield constraints on the BAO power spectrum and provide a test-bed for our calibration scheme. I will discuss the CHIME calibration requirements and describe instrumentation we are developing to meet these requirements.

Shortwave surface radiation network for observing small-scale cloud inhomogeneity fields

NASA Astrophysics Data System (ADS)

Lakshmi Madhavan, Bomidi; Kalisch, John; Macke, Andreas

2016-03-01

As part of the High Definition Clouds and Precipitation for advancing Climate Prediction Observational Prototype Experiment (HOPE), a high-density network of 99 silicon photodiode pyranometers was set up around Jülich (10 km × 12 km area) from April to July 2013 to capture the small-scale variability of cloud-induced radiation fields at the surface. In this paper, we provide the details of this unique setup of the pyranometer network, data processing, quality control, and uncertainty assessment under variable conditions. Some exemplary days with clear, broken cloudy, and overcast skies were explored to assess the spatiotemporal observations from the network along with other collocated radiation and sky imager measurements available during the HOPE period.

User Observed Estimates of Cloud Fraction for Modifying a Cloud-free UV Index for Use in an Educational Smart-phone Application on Erythema

NASA Astrophysics Data System (ADS)

Lantz, K. O.; Long, C. S.; Buller, D.; Berwick, M.; Buller, M.; Kane, I.; Shane, J.

2012-12-01

The UV Index (UVI) is a measure of the skin-damaging UV radiation levels at the Earth's surface. Clouds, haze, air pollution, total ozone, surface elevation, and ground reflectivity affect the levels of UV radiation reaching the ground. The global UV Index was developed as a simple tool to educate the public for taking precautions when exposed to UV radiation to avoid sun-burning, which has been linked to the development of skin cancer. The purpose of this study was to validate an algorithm to modify a cloud-free UV Index forecast for cloud conditions as observed by adults in real-time. The cloud attenuation algorithm is used in a smart-phone application to modify a clear-sky UV Index forecast. In the United States, the Climate Prediction Center of the National Oceanic and Atmospheric Administration's (NOAA) issues a daily UV Index Forecast. The NOAA UV Index is an hourly forecast for a 0.5 x 0.5 degree area and thus has a degree of uncertainty. Cloud cover varies temporally and spatially over short times and distances as weather conditions change and can have a large impact on the UV radiation. The smart-phone application uses the cloud-based UV Index forecast as the default but allows the user to modify a cloud-free UV Index forecast when the predicted sky conditions do not match observed conditions. Eighty four (n=84) adults were recruited to participate in the study through advertisements posted online and in a university e-newsletter. Adults were screened for eligibility (i.e., 18 or older, capable to traveling to test site, had a smart phone with a data plan to access online observation form). A sky observation measure was created to assess cloud fraction. The adult volunteers selected from among four photographs the image that best matched the cloud conditions they observed. Images depicted no clouds (clear sky), thin high clouds, partly cloudy sky, and thick clouds (sky completely overcast). When thin high clouds or partly cloudy images were selected, adults estimated the percentage of the sky covered by clouds. Cloud fraction was calculated by assigning 0% if the clear-sky image was selected, 100% if the overcast thick cloud image was selected, and 10% to 90% as indicated by adults, if high thin clouds or partly cloudy images were selected. The observed cloud fraction from the adult volunteers was compared to the cloud fraction determined by a Total Sky Imager. A cloud modification factor based on the observed cloud fraction was applied to the cloud-free UV Index forecast. This result was compared to the NOAA cloudy sky UV Index forecast and to the concurrent UV Index measurements from three broadband UV radiometers and a Brewer spectrophotometer calibrated using NIST traceable standards.

Dark Skies Awareness Cornerstone Project for the International Year of Astronomy

NASA Astrophysics Data System (ADS)

Walker, C. E.; Pompea, S. M.; Iya Dark Skies Awareness Working Group

2010-12-01

Programs that were part of the International Year of Astronomy 2009 (IYA2009) Dark Skies Awareness (DSA) Cornerstone Project have been successfully implemented around the world to promote social awareness of the effects of light pollution on public health, economic issues, ecological consequences, energy conservation, safety and security, nightscape aesthetics and especially astronomy. In developing the programs, DSA Cornerstone Project found that to influence cultural change effectively — to make people literally look up and see the light — we must make children a main focus, use approaches that offer involvement on many levels, from cursory to committed, and offer involvement via many venues. We must make the programs and resources as turn-key as possible, especially for educators — and provide ways to visualize the problem with simple, easily grasped demonstrations. The programs spanned a wide range; from new media technology for the younger generation, to an event in the arts, to various types of educational materials, to the promotion of dark skies communities, to national and international events and to global citizen science programs. The DSA Cornerstone Project is continuing most all of these programs beyond IYA2009. The International Dark-Sky Association as well as the Starlight Initiative is endorsing and helping to continue with some of the most successful programs from the DSA. The GLOBE at Night campaign is adding a research component that examines light pollution’s affects on wildlife. Dark Skies Rangers activities are being implemented in Europe through the Galileo Teacher Training Program. The new “One Star at a Time” will engage people to protect the night sky through personal pledges and registration of public stargazing areas or StarParks, like the newest one in Italy. The Starlight Initiative’s World Night in Defence of the Starlight will take place on the Vernal Equinox. DSA will again oversee the Dark Skies portion of Global Astronomy Month, in which the International Dark Sky Week will be celebrated. DSA will be collaborating with Belgium’s “Night of Darkness” to endeavor to make that lights out event a more global event. DSA will endeavor to support dark skies education worldwide, as in Northern Ireland. DSA will seek to expand light pollution prevention campaigns like Austria’s. People whose homes meet the criteria of good lighting are invited to put a sticker from Austria’s biggest newspaper in their front window to show their support. DSA also seeks to collaborate with the IAU Office for Astronomy Development. The presentation will focus on the DSA programs during IYA and the sustainability of the DSA programs after IYA, as well as the expansion to other programs worldwide, with particular emphasis in communicating dark skies awareness with the public and its educational value in attracting young people to study science and technology. See www.darkskiesawareness.org for more information on the programs.

Construction, Deployment and Data Analysis of the E and B EXperiment: A Cosmic Microwave Background Polarimeter

NASA Astrophysics Data System (ADS)

Didier, Joy

The E and B EXperiment (EBEX) is a pointed balloon-borne telescope designed to measure the polarization of the cosmic microwave background (CMB) as well as that from Galactic dust. The instrument is equipped with a 1.5 meter aperture Gregorian-Dragone telescope, providing an 8' beam at three frequency bands centered on 150, 250 and 410 GHz. The telescope is designed to measure or place an upper limit on inflationary B-mode signals and to probe B-modes originating from gravitationnal lensing of the CMB. The higher EBEX frequencies are designed to enable the measurement and removal of polarized Galactic dust foregrounds which currently limit the measurement of inflationary B-modes. Polarimetry is achieved by rotating an achromatic half-wave plate (HWP) on a superconducting magnetic bearing. In January 2013, EBEX completed 11 days of observations in a flight over Antarctica covering 6,000 square degrees of the southern sky. This marks the first time that kilo-pixel TES bolometer arrays have made science observations on a balloon-borne platform. In this thesis we report on the construction, deployment and data analysis of EBEX. We review the development of the pointing sensors and software used for real-time attitude determination and control, including pre-flight testing and calibration. We then report on the 2013 long duration flight (LD2013) and review all the major stages of the analysis pipeline used to transform the ˜1 TB of raw data into polarized sky maps. We review "LEAP", the software framework developed to support the analysis pipeline. We discuss in detail the novel program developed to reconstruct the attitude post-flight and estimate the effect of attitude errors on measured B-mode signals. We describe the bolometer time-stream cleaning procedure including removing the HWP-synchronous signal, and we detail the map making procedure. Finally we present a novel method to measure and subtract instrumental polarization, after which we show Galaxy and CMB maps.

The Off-plane Grating Rocket Experiment

NASA Astrophysics Data System (ADS)

Donovan, Benjamin

2018-01-01

The next generation of X-ray spectrometers necessitate significant increases in both resolution and effective area to achieve the science goals set forth in the 2010 Decadal Survey and the 2013 Astrophysics Roadmap. The Off-plane Grating Rocket Experiment (OGRE), an X-ray spectroscopy suborbital rocket payload currently scheduled for launch in Q3 2020, will serve as a testbed for several key technologies which can help achieve the desired performance increases of future spectrometers. OGRE will be the first instrument to fly mono-crystalline silicon X-ray mirrors developed at NASA Goddard Space Flight Center. The payload will also utilize an array of off-plane gratings manufactured at The Pennsylvania State University. Additionally, the focal plane will be populated with an array of four electron-multiplying CCDs developed by the Open University and XCAM Ltd. With these key technologies, OGRE hopes to achieve the highest resolution on-sky soft X-ray spectrum to date. We discuss the optical design, expected performance, and the current status of the payload.

The LWA1 Low Frequency Sky Survey

NASA Astrophysics Data System (ADS)

Dowell, Jayce; Taylor, Gregory B.; LWA Collaboration

2015-01-01

The LWA1 Low Frequency Sky Survey is a survey of the sky visible from the first station of the Long Wavelength Array (LWA1) across the frequency range of 35 to 80 MHz. The primary motivation behind this effort is to improve our understanding of the sky at these frequencies. In particular, an understanding of the low frequency foreground emission is necessary for work on detecting the epoch of reionization and the cosmic dark ages where the foreground signal dwarfs the expected redshifted HI signal by many orders of magnitude (Pritchard & Loeb 2012, Rep. Prog. Phys., 75, 086901). The leading model for the sky in the frequency range of 20 to 200 MHz is the Global Sky Model (GSM) by de Oliveria-Costas et al. (2008, MNRAS, 288, 247). This model is based upon a principle component analysis of 11 sky maps ranging in frequency from 10 MHz to 94 GHz. Of these 11 maps, only four are below 1 GHz; 10 MHz from Caswell (1976, MNRAS, 177, 601), 22 MHz from Roger et al. (1999, A&AS, 137, 7), 45 MHz from Alvarez et al. (1997, A&AS, 124, 315) and Maeda et al. (1999, A&AS, 140, 145), and 408 MHz from Haslam et al. (1982, A&AS, 47, 1). Thus, within this model, the region of interest to both cosmic dawn and the epoch of reionization is largely unconstrained based on the available survey data, and are also limited in terms of the spatial coverage and calibration. A self-consistent collection of maps is necessary for both our understanding of the sky and the removal of the foregrounds that mask the redshifted 21-cm signal.We present the current state of the survey and discuss the imaging and calibration challenges faced by dipole arrays that are capable of imaging nearly 2π steradians of sky simultaneously over a large fractional bandwidth.Construction of the LWA has been supported by the Office of Naval Research under Contract N00014-07-C-0147. Support for operations and continuing development of the LWA1 is provided by the National Science Foundation under grants AST-1139963 and AST-1139974 of the University Radio Observatory program.

Systematic measurements of the night sky brightness at 26 locations in Eastern Austria

NASA Astrophysics Data System (ADS)

Posch, Thomas; Binder, Franz; Puschnig, Johannes

2018-05-01

We present an analysis of the zenithal night sky brightness (henceforth: NSB) measurements at 26 locations in Eastern Austria focussing on the years 2015-2016, both during clear and cloudy to overcast nights. All measurements have been performed with 'Sky Quality Meters' (SQMs). For some of the locations, simultaneous aerosol content measurements are available, such that we were able to find a correlation between light pollution and air pollution at those stations. For all locations, we examined the circalunar periodicity of the NSB, seasonal variations as well as long-term trends in the recorded light pollution. The latter task proved difficult, however, due to varying meteorological conditions, potential detector 'aging' and other effects. For several remote locations, a darkening of the overcast night sky by up to 1 magnitude is recorded - indicating a very low level of light pollution -, while for the majority of the examined locations, a brightening of the night sky by up to a factor of 15 occurs due to clouds. We present suitable ways to plot and analyze huge long-term NSB datasets, such as mean-NSB histograms, circalunar, annual ('hourglass') and cumulative ('jellyfish') plots. We show that five of the examined locations reach sufficiently low levels of light pollution - with NSB values down to 21.8 magSQM/arcsec2 - as to allow the establishment of dark sky reserves, even to the point of reaching the 'gold tier' defined by the International Dark Sky Association. Based on the 'hourglass' plots, we find a strong circalunar periodicity of the NSB in small towns and villages ( < 5.000 inhabitants), with amplitudes of up to 5 magnitudes. Using the 'jellyfish' plots, on the other hand, we demonstrate that the examined city skies brighten by up to 3 magnitudes under cloudy conditions, which strongly dominate in those cumulative data representations. Nocturnal gradients of the NSB of 0.0-0.14 magSQM/arcsec2/h are found. The long-term development of the night sky brightness was evaluated based on the 2012-17 data for one of our sites, possibly indicating a slight ( 2%) decrease of the mean zenithal NSB at the Vienna University Observatory.

The GLOBE at Night Campaign: Promoting Dark Skies Awareness Beyond IYA2009

NASA Astrophysics Data System (ADS)

Walker, Constance E.

2010-01-01

One of the most productive programs in the IYA2009 Dark Skies Awareness Cornerstone Project has been GLOBE at Night. The GLOBE at Night program has endeavored to promote social awareness of the dark sky by getting the general public to measure light pollution and submit results on-line. During IYA2009 alone, over 15,700 measurements from 70 countries were contributed during the 2-week campaign period. That amount is twice the number of measurements on average from previous years. The GLOBE at Night website explains clearly the simple-to-participate-in 5 step program and offers background information and interactive games on key concepts. The program has been expanded to include trainings of the general public, but especially educators in schools, museums and science centers, in unique ways. Education kits for Dark Skies Awareness have been distributed at these training workshops. The kit includes material for a light shielding demonstration, a digital Sky Quality Meter and Dark Skies Ranger Activities. The activities are on how unshielded light wastes energy, how light pollution affects wildlife and how you can participate in a citizen-science star-hunt like GLOBE at Night. In addition, projects are being developed for what to do with the data once it is taken. There were particularly spirited and creative GLOBE at Night campaigns around the world in 2009. One such "poster child” was carried out by 6500 students in northern Indiana. The students produced 3,391 GLOBE at Night measurements. To visualize the magnitudes of dark sky lost to light pollution, these students removed over 12,000 of the 35,000 stacked LEGO blocks that represented an ideal night sky across the school district. The presentation will provide an update with lessons learned, describe how people can become involved and take a look ahead at the program's sustainability. For further information, visit www.globe.gov/globeatnight.

Astronomy in the training of teachers and the role of practical rationality in sky observation

NASA Astrophysics Data System (ADS)

Bretones, P. S.; Compiani, M.

2006-08-01

This work analyses a program in the training of teachers that departs from the courses based on the technical rationality. An Astronomy course was offered to Science and Geography teachers of the four last years of high school education, comprising 46 hours, and organized in 2002 by the Instituto Superior de Ciências Aplicadas in Limeira, Brazil. Following the course a study group was established and held five meetings. The data was obtained through assessments, interviews, and accounts by the teachers and records from the classes and meetings. The actions and conceptual changes and the role of the Practical Rationality were then investigated. It was verified that for sky observation, the model of Practical Rationality within the reflective teacher theoretical framework and tutorial actions leads to knowledge acquisition, conceptual changes and extracurricular activities. Examples are: suggestions, personal actions of the teachers without their students, accounts of extracurricular activities and development of astronomical contents in class, actions in the pedagogical practices and reflections of the teachers with the teacher/ researcher towards the assessment of such changes are shown. It is important to stress that sky observation has specific features that lead to an equally specific school practice, in which the contents and procedures based on observations and their representation point towards a more practical rationality. Even in a training course for teachers based on technical rationality, the introduction of sky observation deepens the practical rationality and the development of principles that guide the acquisition and the teaching of knowledge about sky observation.

Pilot Studies of Geologic and Terrestrial Carbon Sequestration in the Big Sky Region, USA, and Opportunities for Commercial Scale Deployment of New Technologies

NASA Astrophysics Data System (ADS)

Waggoner, L. A.; Capalbo, S. M.; Talbott, J.

2007-05-01

Within the Big Sky region, including Montana, Idaho, South Dakota, Wyoming and the Pacific Northwest, industry is developing new coal-fired power plants using the abundant coal and other fossil-based resources. Of crucial importance to future development programs are robust carbon mitigation plans that include a technical and economic assessment of regional carbon sequestration opportunities. The objective of the Big Sky Carbon Sequestration Partnership (BSCSP) is to promote the development of a regional framework and infrastructure required to validate and deploy carbon sequestration technologies. Initial work compiled sources and potential sinks for carbon dioxide (CO2) in the Big Sky Region and developed the online Carbon Atlas. Current efforts couple geologic and terrestrial field validation tests with market assessments, economic analysis and regulatory and public outreach. The primary geological efforts are in the demonstration of carbon storage in mafic/basalt formations, a geology not yet well characterized but with significant long-term storage potential in the region and other parts of the world; and in the Madison Formation, a large carbonate aquifer in Wyoming and Montana. Terrestrial sequestration relies on management practices and technologies to remove atmospheric CO2 to storage in trees, plants, and soil. This indirect sequestration method can be implemented today and is on the front-line of voluntary, market-based approaches to reduce CO2 emissions. Details of pilot projects are presented including: new technologies, challenges and successes of projects and potential for commercial-scale deployment.

Intelligent vibration control of ELTs and large AO hardware

NASA Astrophysics Data System (ADS)

Pott, J.-U.; Kürster, M.; Trowitzsch, J.; Borelli, J.; Rohloff, R.-R.; Herbst, T.; Böhm, M.; Keck, A.; Ruppel, T.; Sawodny, O.

2012-07-01

MPIA leads the construction of the LINC-NIRVANA instrument, the MCAO-supported Fizeau imager for the LBT, serves as pathfinder for future ELT-AO imagers in terms of size and technology. In this contribution, we review recent results and significant progress made on the development of key items of our stratgey to achieve a piston stability of up to 100nm during a science exposure. We present an overview of our vibration control strategies for optical path and tip-tilt stabilization, involving accelerometer based real-time vibration measurements, vibration sensitive active control of actuators, and the development of a dynamical model of the LBT. MPIA also co-develops the E-ELT first-light NIR imager MICADO (both SCAO and MCAO assisted). Our experiences, made with LINC-NIRVANA, will be fed into the MICADO structural AO design to reach highest on-sky sensitivity.

Dark Skies Preservation through Responsible Lighting: the IYL2015 Quality Lighting Kit

NASA Astrophysics Data System (ADS)

Walker, Constance E.

2015-01-01

Poor quality lighting not only impedes astronomy research, but creates safety issues, affects human circadian sensitivities, disrupts ecosystems, and wastes more than a few billion dollars/year of energy in the USA alone. The United Nations-sanctioned the International Year of Light in 2015 (IYL2015) is providing an opportunity to increase public awareness of dark skies preservation, quality lighting and energy conservation. The Education and Public Outreach (EPO) group at the National Optical Astronomy Observatory (NOAO) has received a small grant through the International Astronomical Union (IAU) to produce official 'Quality Lighting Teaching Kits' for the IYL2015 cornerstone theme, 'Cosmic Light'. These kits will emphasize the use of proper optical design in achieving quality lighting that promotes both energy efficiency and energy conservation of an endangered natural resource, our dark skies. The concepts and practice of 'quality lighting' will be explored through demonstrations, hands-on/minds-on activities, formative assessment probes, and engineering design projects that explore basic principles of optics and the physics of light. The impact of the kits will be amplified by providing professional development using tutorial videos created at NOAO and conducting question and answer sessions via Google+ Hangouts for the outreach volunteers. The quality lighting education program will leverage NOAO EPO's work in the last ten years on lighting and optics education (e.g., the IAU 'Dark Skies Africa', APS 'Dark Skies Yuma' and 'Hands-On Optics' programs). NOAO's partners are CIE (International Commission on Illumination), IDA (International Dark-Sky Association) and SPIE (International Society for Optics and Photonics), as well as the IAU Office of Astronomy for Development, Galileo Teacher Training Program, Universe Awareness, and Global Hands-on Universe. Their networks will disseminate the program and kits to formal and informal audiences worldwide. The impact sought is a change in knowledge, attitude, and behavior in each community by learning how to light responsibly, improving the quality of life in 'illuminating' ways.

Development Unit Configuration and Current Status of the MIP/MTERC Experiment

NASA Technical Reports Server (NTRS)

Juanero, K. J.; Johnson, K. R.

1999-01-01

The Mars In-Situ Propellant Production (ISPP) Precursor (MIP) experiment package is planned for inclusion on the Mars 2001 Lander. This experiment package consists of five experiments whose purpose is to demonstrate the performance of various ISPP processes in-situ on Mars. The demonstrated ability to produce propellant for Mars Return Vehicles (MRV) is considered to be a necessary precursor to any future manned mission to Mars. The Mars Thermal Environment/Radiator Characterization (MTERC) experiment is part of the MIP package and is intended to determine the Mars night sky temperature as well as to characterize the performance degradation of radiators caused by environmental exposure on Mars over time. Radiators are needed as part of the ISPP process to remove heat from the Mars Atmosphere Acquisition and Compression (MAAC) C02 sorption compressor. MTERC will provide the data needed to optimize the design of radiators for ISPP and other processes. A MTERC Development Unit (DU) has been fabricated and tested at JPL. The MTERC DU consists of: (1) a radiator subassembly, (2) a motor/cover subassembly, (3) a differential temperature control circuit and motor control electronics circuit board, and (4) a command and data handling electronics circuit board. This paper will describe the operational theory and the configuration of the MTERC DU and will discuss the current status of the MTERC experiment development including some selected results of performance testing that has been completed prior to the ISRU III meeting.

Development Unit Configuration and Current Status of the MIP/MTERC Experiment

NASA Technical Reports Server (NTRS)

Juanero, K. J.; Johnson, K. R.

1999-01-01

The Mars In-Situ Propellant Production (ISPP) Precursor (MIP) experiment package is planned for inclusion on the Mars 2001 Lander. This experiment package consists of five experiments whose purpose is to demonstrate the performance of various ISPP processes in-situ on Mars. The demonstrated ability to produce propellant for Mars Return Vehicles (MRV) is considered to be a necessary precursor to any future manned mission to Mars. The Mars Thermal Environment/Radiator Characterization (MTERC) experiment is part of the MIP package and is intended to determine the Mars night sky temperature as well as to characterize the performance degradation of radiators caused by environmental exposure on Mars over time. Radiators are needed as part of the ISPP process to remove heat from the Mars Atmosphere Acquisition and Compression (MAAC) CO2 sorption compressor. MTERC will provide the data needed to optimize the design of radiators for ISPP and other processes. A MTERC Development Unit (DU) has been fabricated and tested at JPL. The MTERC DU consists of 1) a radiator subassembly, 2) a motor/cover subassembly, 3) a differential temperature control circuit and motor control electronics circuit board, and 4) a command and data handling electronics circuit board. This paper will describe the operational theory and the configuration of the MTERC DU and will discuss the current status of the MTERC experiment development including some selected results of performance testing that has been completed prior to the ISRU III meeting.

Science with the VLA Sky Survey (VLASS)

NASA Astrophysics Data System (ADS)

Murphy, Eric J.; Baum, Stefi Alison; Brandt, W. Niel; Chandler, Claire J.; Clarke, Tracy E.; Condon, James J.; Cordes, James M.; Deustua, Susana E.; Dickinson, Mark; Gugliucci, Nicole E.; Hallinan, Gregg; Hodge, Jacqueline; Lang, Cornelia C.; Law, Casey J.; Lazio, Joseph; Mao, Sui Ann; Myers, Steven T.; Osten, Rachel A.; Richards, Gordon T.; Strauss, Michael A.; White, Richard L.; Zauderer, Bevin; Extragalactic Science Working Group, Galactic Science Working Group, Transient Science Working Group

2015-01-01

The Very Large Array Sky Survey (VLASS) was initiated to develop and carry out a new generation large radio sky survey using the recently upgraded Karl G. Jansky Very Large Array. The proposed VLASS is a modern, multi-tiered survey with the VLA designed to provide a broad, cohesive science program with forefront scientific impact, capable of generating unexpected scientific discoveries, generating involvement from all astronomical communities, and leaving a lasting legacy value for decades.VLASS will observe from 2-4 GHz and is structured to combine comprehensive all sky coverage with sequentially deeper coverage in carefully identified parts of the sky, including the Galactic plane, and will be capable of informing time domain studies. This approach enables both focused and wide ranging scientific discovery through the coupling of deeper narrower tiers with increasing sky coverage at shallower depths, addressing key science issues and providing a statistical interpretational framework. Such an approach provides both astronomers and the citizen scientist with information for every accessible point of the radio sky, while simultaneously addressing fundamental questions about the nature and evolution of astrophysical objects.VLASS will follow the evolution of galaxies and their central black hole engines, measure the strength and topology of cosmic magnetic fields, unveil hidden explosions throughout the Universe, and chart our galaxy for stellar remnants and ionized bubbles. Multi-wavelength communities studying rare objects, the Galaxy, radio transients, or galaxy evolution out to the peak of the cosmic star formation rate density will equally benefit from VLASS.Early drafts of the VLASS proposal are available at the VLASS website (https://science.nrao.edu/science/surveys/vlass/vlass), and the final proposal will be posted in early January 2015 for community comment before undergoing review in March 2015. Upon approval, VLASS would then be on schedule to start observing in 2016.

Light Pollution in Ultraviolet and Visible Spectrum: Effect on Different Visual Perceptions

PubMed Central

Solano Lamphar, Héctor Antonio; Kocifaj, Miroslav

2013-01-01

In general terms, lighting research has been focused in the development of artificial light with the purpose of saving energy and having more durable lamps. However, the consequences that artificial night lighting could bring to the human being and living organisms have become an important issue recently. Light pollution represents a significant problem to both the environment and human health causing a disruption of biological rhythms related not only to the visible spectrum, but also to other parts of the electromagnetic spectrum. Since the lamps emit across a wide range of the electromagnetic spectrum, all photobiological species may be exposed to another type of light pollution. By comparing five different lamps, the present study attempts to evaluate UV radiative fluxes relative to what humans and two species of insects perceive as sky glow level. We have analyzed three atmospheric situations: clear sky, overcast sky and evolving precipitable water content. One important finding suggests that when a constant illuminance of urban spaces has to be guaranteed the sky glow from the low pressure sodium lamps has the most significant effect to the visual perception of the insects tested. But having the fixed number of luminaires the situation changes and the low pressure sodium lamp would be the best choice for all three species. The sky glow effects can be interpreted correctly only if the lamp types and the required amount of scotopic luxes at the ground are taken into account simultaneously. If these two factors are combined properly, then the ecological consequences of sky glow can be partly reduced. The results of this research may be equally useful for lighting engineers, architects, biologists and researchers who are studying the effects of sky glow on humans and biodiversity. PMID:23441205

Super-sample covariance approximations and partial sky coverage

NASA Astrophysics Data System (ADS)

Lacasa, Fabien; Lima, Marcos; Aguena, Michel

2018-04-01

Super-sample covariance (SSC) is the dominant source of statistical error on large scale structure (LSS) observables for both current and future galaxy surveys. In this work, we concentrate on the SSC of cluster counts, also known as sample variance, which is particularly useful for the self-calibration of the cluster observable-mass relation; our approach can similarly be applied to other observables, such as galaxy clustering and lensing shear. We first examined the accuracy of two analytical approximations proposed in the literature for the flat sky limit, finding that they are accurate at the 15% and 30-35% level, respectively, for covariances of counts in the same redshift bin. We then developed a harmonic expansion formalism that allows for the prediction of SSC in an arbitrary survey mask geometry, such as large sky areas of current and future surveys. We show analytically and numerically that this formalism recovers the full sky and flat sky limits present in the literature. We then present an efficient numerical implementation of the formalism, which allows fast and easy runs of covariance predictions when the survey mask is modified. We applied our method to a mask that is broadly similar to the Dark Energy Survey footprint, finding a non-negligible negative cross-z covariance, i.e. redshift bins are anti-correlated. We also examined the case of data removal from holes due to, for example bright stars, quality cuts, or systematic removals, and find that this does not have noticeable effects on the structure of the SSC matrix, only rescaling its amplitude by the effective survey area. These advances enable analytical covariances of LSS observables to be computed for current and future galaxy surveys, which cover large areas of the sky where the flat sky approximation fails.

Light pollution in ultraviolet and visible spectrum: effect on different visual perceptions.

PubMed

Solano Lamphar, Héctor Antonio; Kocifaj, Miroslav

2013-01-01

In general terms, lighting research has been focused in the development of artificial light with the purpose of saving energy and having more durable lamps. However, the consequences that artificial night lighting could bring to the human being and living organisms have become an important issue recently. Light pollution represents a significant problem to both the environment and human health causing a disruption of biological rhythms related not only to the visible spectrum, but also to other parts of the electromagnetic spectrum. Since the lamps emit across a wide range of the electromagnetic spectrum, all photobiological species may be exposed to another type of light pollution. By comparing five different lamps, the present study attempts to evaluate UV radiative fluxes relative to what humans and two species of insects perceive as sky glow level. We have analyzed three atmospheric situations: clear sky, overcast sky and evolving precipitable water content. One important finding suggests that when a constant illuminance of urban spaces has to be guaranteed the sky glow from the low pressure sodium lamps has the most significant effect to the visual perception of the insects tested. But having the fixed number of luminaires the situation changes and the low pressure sodium lamp would be the best choice for all three species. The sky glow effects can be interpreted correctly only if the lamp types and the required amount of scotopic luxes at the ground are taken into account simultaneously. If these two factors are combined properly, then the ecological consequences of sky glow can be partly reduced. The results of this research may be equally useful for lighting engineers, architects, biologists and researchers who are studying the effects of sky glow on humans and biodiversity.

Fireballs in the Sky

NASA Astrophysics Data System (ADS)

Day, B. H.; Bland, P.

2016-12-01

Fireballs in the Sky is an innovative Australian citizen science program that connects the public with the research of the Desert Fireball Network (DFN). This research aims to understand the early workings of the solar system, and Fireballs in the Sky invites people around the world to learn about this science, contributing fireball sightings via a user-friendly app. To date, more than 23,000 people have downloaded the app world-wide and participated in planetary science. The Fireballs in the Sky app allows users to get involved with the Desert Fireball Network research, supplementing DFN observations and providing enhanced coverage by reporting their own meteor sightings to DFN scientists. Fireballs in the Sky reports are used to track the trajectories of meteors - from their orbit in space to where they might have landed on Earth. Led by Phil Bland at Curtin University in Australia, the Desert Fireball Network (DFN) uses automated observatories across Australia to triangulate trajectories of meteorites entering the atmosphere, determine pre-entry orbits, and pinpoint their fall positions. Each observatory is an autonomous intelligent imaging system, taking 1000×36Megapixel all-sky images throughout the night, using neural network algorithms to recognize events. They are capable of operating for 12 months in a harsh environment, and store all imagery collected. We developed a completely automated software pipeline for data reduction, and built a supercomputer database for storage, allowing us to process our entire archive. The DFN currently stands at 50 stations distributed across the Australian continent, covering an area of 2.5 million km^2. Working with DFN's partners at NASA's Solar System Exploration Research Virtual Institute, the team is expanding the network beyond Australia to locations around the world. Fireballs in the Sky allows a growing public base to learn about and participate in this exciting research.

Gamma-Ray Astronomy Across 6 Decades of Energy: Synergy between Fermi, IACTs, and HAWC

NASA Technical Reports Server (NTRS)

Hui, C. Michelle

2017-01-01

Gamma Ray Observatories, Gamma-Ray Astrophysics, GeV TeV Sky Survey, Galaxy, Galactic Plane, Source Distribution, The gamma-ray sky is currently well-monitored with good survey coverage. Many instruments from different waveband/messenger (X rays, gamma rays, neutrinos, gravitational waves) available for simultaneous observations. Both wide-field and pointing instruments in development and coming online in the next decade LIGO

Validation of BlueSky Smoke Prediction System using surface and satellite observations during major wildland fire events in Northern California

Treesearch

Lesley Fusina; Sharon Zhong; Julide Koracin; Tim Brown; Annie Esperanza; Leland Tarney; Haiganoush Preisler

2007-01-01

The BlueSky Smoke Prediction System developed by the U.S. Department of Agriculture, Forest Service, AirFire Team under the National Fire Plan is a modeling framework that integrates tools, knowledge of fuels, moisture, combustion, emissions, plume dynamics, and weather to produce real-time predictions of the cumulative impacts of smoke from wildfires, prescribed fires...

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.

The Planck Legacy Archive

NASA Astrophysics Data System (ADS)

Dupac, X.; Arviset, C.; Fernandez Barreiro, M.; Lopez-Caniego, M.; Tauber, J.

2015-12-01

The Planck Collaboration has released in 2015 their second major dataset through the Planck Legacy Archive (PLA). It includes cosmological, Extragalactic and Galactic science data in temperature (intensity) and polarization. Full-sky maps are provided with unprecedented angular resolution and sensitivity, together with a large number of ancillary maps, catalogues (generic, SZ clusters and Galactic cold clumps), time-ordered data and other information. The extensive cosmological likelihood package allows cosmologists to fully explore the plausible parameters of the Universe. A new web-based PLA user interface is made public since Dec. 2014, allowing easier and faster access to all Planck data, and replacing the previous Java-based software. Numerous additional improvements to the PLA are also being developed through the so-called PLA Added-Value Interface, making use of an external contract with the Planetek Hellas and Expert Analytics software companies. This will allow users to process time-ordered data into sky maps, separate astrophysical components in existing maps, simulate the microwave and infrared sky through the Planck Sky Model, and use a number of other functionalities.

Looking skyward to study ecosystem carbon dynamics

USGS Publications Warehouse

Dye, Dennis G.

2012-01-01

Between May and October 2011 the U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Energy's Atmospheric Radiation Measurement (ARM) program, conducted a field campaign at the ARM Southern Great Plains site in north central Oklahoma to evaluate a new instrument for quantitative image-based monitoring of sky conditions and solar radiation. The High Dynamic Range All-Sky Imaging System (HDR-ASIS) was developed by USGS to support studies of cloud- and aerosol-induced variability in the geometric properties of solar radiation (the sky radiance distribution) and its effects on photosynthesis and uptake of carbon dioxide (CO2) by terrestrial ecosystems. Under a clean, cloudless atmosphere when the Sun is above the horizon, most of the solar radiation reaching an area of the Earth's surface is concentrated in a beam coming directly from the Sun; a relatively small proportion arrives as diffuse radiation from the rest of the sky. Clouds and atmospheric aerosols cause increased scattering of the beam radiation, which increases the proportion of diffuse radiation at the surface.

Stereoscopic determination of all-sky altitude map of aurora using two ground-based Nikon DSLR cameras

NASA Astrophysics Data System (ADS)

Kataoka, R.; Miyoshi, Y.; Shigematsu, K.; Hampton, D.; Mori, Y.; Kubo, T.; Yamashita, A.; Tanaka, M.; Takahei, T.; Nakai, T.; Miyahara, H.; Shiokawa, K.

2013-09-01

A new stereoscopic measurement technique is developed to obtain an all-sky altitude map of aurora using two ground-based digital single-lens reflex (DSLR) cameras. Two identical full-color all-sky cameras were set with an 8 km separation across the Chatanika area in Alaska (Poker Flat Research Range and Aurora Borealis Lodge) to find localized emission height with the maximum correlation of the apparent patterns in the localized pixels applying a method of the geographical coordinate transform. It is found that a typical ray structure of discrete aurora shows the broad altitude distribution above 100 km, while a typical patchy structure of pulsating aurora shows the narrow altitude distribution of less than 100 km. Because of its portability and low cost of the DSLR camera systems, the new technique may open a unique opportunity not only for scientists but also for night-sky photographers to complementarily attend the aurora science to potentially form a dense observation network.

Design Analysis of Corridors-in-the-Sky

NASA Technical Reports Server (NTRS)

Xue, Min

2008-01-01

Corridors-in-the-sky or tubes is one of new concepts in dynamic airspace configuration. It accommodates high density traffic, which has similar trajectories. Less air traffic controllers workload is expected than classic airspaces, thus, corridors-in-the-sky may increase national airspace capacity and reduce flight delays. To design corridors-in-the-sky, besides identifying their locations, their utilization, altitudes, and impacts on remaining system need to be analyzed. This paper chooses one tube candidate and presents analyses of spatial and temporal utilization of the tube, the impact on the remaining traffic, and the potential benefit caused by off-loading the traffic from underlying sectors. Fundamental issues regarding to the benefits have been also clarified. Methods developed to assist the analysis are described. Analysis results suggest dynamic tubes in terms of varied utilizations during different time periods. And it is found that combined lane options would be a good choice to lower the impact on non-tube users. Finally, it shows significant reduction of peak aircraft count in underlying sectors with only one tube enabled.

University of Wisconsin Cirrus Remote Sensing Pilot Experiment

NASA Technical Reports Server (NTRS)

Ackerman, Steven A.; Eloranta, Ed W.; Grund, Chris J.; Knuteson, Robert O.; Revercomb, Henry E.; Smith, William L.; Wylie, Donald P.

1993-01-01

During the period of 26 October 1989 through 6 December 1989 a unique complement of measurements was made at the University of Wisconsin-Madison to study the radiative properties of cirrus clouds. Simultaneous observations were obtained from a scanning lidar, two interferometers, a high spectral resolution lidar, geostationary and polar orbiting satellites, radiosonde launches, and a whole-sky imager. This paper describes the experiment, the instruments deployed, and, as an example, the data collected during one day of the experiment.

Experimental history: swinging pendulums and melting shellac.

PubMed

Palmieri, Paolo

2009-09-01

Four hundred years ago Galileo Galilei aimed a telescope at the sky. He revolutionized astronomy. Equally revolutionary were his experiments in physics. Unlike his astronomical observations the experiments remain difficult to understand and replicate even today. Two centuries after Galileo, Augustin Coulomb demonstrated experimentally the law of electrostatic force. It has never been successfully replicated. Yet both Galileo and Coulomb were exquisite experimentalists. The fact is that revolutionary experiments in physics are never finished. They are open for investigation for generations to come.

Validation of the Effectiveness of Simulator Experience vs Real-World Operational Experience in the Port of Valdez.

DTIC Science & Technology

1982-11-01

skills and the re- the safety of ships. The arrival of tention of such skills VLCCs and other ships of unprece- dented size in these waters created...Off Frack )eviation for Subjects with Simu- for Subjects with Valde: lator and No Simulator and No Valdez rhxperience 0 Experience The commonly...generator ownship’s maneuvers. The sky is de- also drives the collision avoidance picted without clouds and the water system, which can be slaved to

The Cosmic Twilight Polarimeter: A Model-Independent Approach to Measure the Sky-averaged Foreground Spectrum for Global 21-cm Cosmology

NASA Astrophysics Data System (ADS)

Nhan, Bang; Bradley, Richard F.; Burns, Jack O.

2018-06-01

Detecting the cosmological sky-averaged (global) 21 cm spectrum as a function of observed frequency will provide a powerful tool to study the ionization and thermal history of intergalactic medium (IGM) in the high-redshift Universe (400 million years after the Big Bang). The biggest challenge in conventional ground-based total-power global 21 cm experiments is the removal of the Galactic and extragalactic synchrotron foreground (1E4-1E5 K) to uncover the weak cosmological signal (10-100 mK) due to corruptions on the spectral smoothness of foreground spectrum by instrumental effects. Although an absorption profile has been reported recently at 78 MHz in the sky-averaged spectrum by the Experiment to Detect the Global Epoch of Reionization Signature (EDGES) experiment, it is necessary to confirm that the proposed observation is indeed the global 21 cm signal with an independent approach. In this presentation, we propose a new polarimetry-based observational approach that relies on the dynamic characteristics of the foreground emission at the circumpolar region to track and remove the foreground spectrum di- rectly, without relying on any parametric foreground models as in conventional approaches. Due to asymmetry and the Earth's rotation, the projection of the anisotropic foreground sources onto a wide-view antenna pointing at the North Celestial Pole (NCP) can induce a net polarization which varies with time with a unique twice-diurnal periodicity. Different from the zenith-pointing global 21 cm experiments, by using this twice-diurnal signature, the Cosmic Twilight Polarimeter (CTP) is designed to measure and separate the varying foreground from the isotropic cosmological background simultaneously in the same observation. By combining preliminary results of the proof-of-concept instrument with numerical simulations, we present a detailed evaluation for this technique and its feasibility in conducting an independent global 21 cm measurement in the near future.

Anisotropy in the Microwave Sky at 90 GHz: Results from Python III

NASA Astrophysics Data System (ADS)

Platt, S. R.; Kovac, J.; Dragovan, M.; Peterson, J. B.; Ruhl, J. E.

1997-01-01

The third year of observations with the Python microwave background experiment densely samples a 5.5d × 22° region of sky that includes the fields measured during the first 2 years of observations with this instrument. The sky is sampled in two multipole bands centered at l ~ 87 and l ~ 170. These two data sets are analyzed to place limits on fluctuations in the microwave sky at 90 GHz. Interpreting the observed fluctuations as anisotropy in the cosmic microwave background, we find flat-band power estimates of δTl ≡ [l(l + 1)Cl/(2π)]1/2 = 60+15-13 μK at l = 87+18-38 and δTl = 66+17-16 μK at l = 170+69-50. Combining the entire 3 year set of Python observations, we find that the angular power spectrum of fluctuations has a spectral index m = 0.16+.20-.18 and an amplitude δTle = 63+15-14 μK at le = 139+99-34 for the functional form δTl = δTle(l/le)m. The stated uncertainties in the amplitudes and spectral index represent 1 σ confidence intervals in the likelihood added in quadrature with a 20% calibration uncertainty and an estimate of the effects of a +/-0.05d uncertainty in the measured beamwidths. The limits of l are determined from the half-maximum points of the window functions.

Retrieval of Garstang's emission function from all-sky camera images

NASA Astrophysics Data System (ADS)

Kocifaj, Miroslav; Solano Lamphar, Héctor Antonio; Kundracik, František

2015-10-01

The emission function from ground-based light sources predetermines the skyglow features to a large extent, while most mathematical models that are used to predict the night sky brightness require the information on this function. The radiant intensity distribution on a clear sky is experimentally determined as a function of zenith angle using the theoretical approach published only recently in MNRAS, 439, 3405-3413. We have made the experiments in two localities in Slovakia and Mexico by means of two digital single lens reflex professional cameras operating with different lenses that limit the system's field-of-view to either 180º or 167º. The purpose of using two cameras was to identify variances between two different apertures. Images are taken at different distances from an artificial light source (a city) with intention to determine the ratio of zenith radiance relative to horizontal irradiance. Subsequently, the information on the fraction of the light radiated directly into the upward hemisphere (F) is extracted. The results show that inexpensive devices can properly identify the upward emissions with adequate reliability as long as the clear sky radiance distribution is dominated by a largest ground-based light source. Highly unstable turbidity conditions can also make the parameter F difficult to find or even impossible to retrieve. The measurements at low elevation angles should be avoided due to a potentially parasitic effect of direct light emissions from luminaires surrounding the measuring site.

Bayesian analysis of anisotropic cosmologies: Bianchi VIIh and WMAP

NASA Astrophysics Data System (ADS)

McEwen, J. D.; Josset, T.; Feeney, S. M.; Peiris, H. V.; Lasenby, A. N.

2013-12-01

We perform a definitive analysis of Bianchi VIIh cosmologies with Wilkinson Microwave Anisotropy Probe (WMAP) observations of the cosmic microwave background (CMB) temperature anisotropies. Bayesian analysis techniques are developed to study anisotropic cosmologies using full-sky and partial-sky masked CMB temperature data. We apply these techniques to analyse the full-sky internal linear combination (ILC) map and a partial-sky masked W-band map of WMAP 9 yr observations. In addition to the physically motivated Bianchi VIIh model, we examine phenomenological models considered in previous studies, in which the Bianchi VIIh parameters are decoupled from the standard cosmological parameters. In the two phenomenological models considered, Bayes factors of 1.7 and 1.1 units of log-evidence favouring a Bianchi component are found in full-sky ILC data. The corresponding best-fitting Bianchi maps recovered are similar for both phenomenological models and are very close to those found in previous studies using earlier WMAP data releases. However, no evidence for a phenomenological Bianchi component is found in the partial-sky W-band data. In the physical Bianchi VIIh model, we find no evidence for a Bianchi component: WMAP data thus do not favour Bianchi VIIh cosmologies over the standard Λ cold dark matter (ΛCDM) cosmology. It is not possible to discount Bianchi VIIh cosmologies in favour of ΛCDM completely, but we are able to constrain the vorticity of physical Bianchi VIIh cosmologies at (ω/H)0 < 8.6 × 10-10 with 95 per cent confidence.

Classroom in the Sky

ERIC Educational Resources Information Center

Puck, Susan

1971-01-01

Aviation and transportation students of Mt. San Antonio College (California) gained first hand experience of commercial airline operations while learning science, geography, and history on a 39-hour trip on a United Airlines jet. This year's program was designed to acquaint students with the Apollo Space program. (CA)

Surgical lesion of the anterior optic tract abolishes polarotaxis in tethered flying locusts, Schistocerca gregaria.

PubMed

Mappes, Martina; Homberg, Uwe

2007-01-01

Many insects can detect the polarization pattern of the blue sky and rely on polarization vision for sky compass orientation. In laboratory experiments, tethered flying locusts perform periodic changes in flight behavior under a slowly rotating polarizer even if one eye is painted black. Anatomical tracing studies and intracellular recordings have suggested that the polarization vision pathway in the locust brain involves the anterior optic tract and tubercle, the lateral accessory lobe, and the central complex of the brain. To investigate whether visual pathways through the anterior optic tract mediate polarotaxis in the desert locust, we transected the tract on one side and tested polarotaxis (1) with both eyes unoccluded and (2) with the eye of the intact hemisphere painted black. In the second group of animals, but not in the first group, polarotaxis was abolished. Sham operations did not impair polarotaxis. The experiments show that the anterior optic tract is an indispensable part of visual pathways mediating polarotaxis in the desert locust.

Why is the sunny side always up? Explaining the spatial mapping of concepts by language use.

PubMed

Goodhew, Stephanie C; McGaw, Bethany; Kidd, Evan

2014-10-01

Humans appear to rely on spatial mappings to represent and describe concepts. The conceptual cuing effect describes the tendency for participants to orient attention to a spatial location following the presentation of an unrelated cue word (e.g., orienting attention upward after reading the word sky). To date, such effects have predominately been explained within the embodied cognition framework, according to which people's attention is oriented on the basis of prior experience (e.g., sky → up via perceptual simulation). However, this does not provide a compelling explanation for how abstract words have the same ability to orient attention. Why, for example, does dream also orient attention upward? We report on an experiment that investigated the role of language use (specifically, collocation between concept words and spatial words for up and down dimensions) and found that it predicted the cuing effect. The results suggest that language usage patterns may be instrumental in explaining conceptual cuing.

"Dark Skies, Bright Kids" - First Year Of Outreach In Rural Virginia

NASA Astrophysics Data System (ADS)

Ries, Paul; Johnson, K.; Zasowski, G.; Beaton, R.; Carlberg, J.; Czekala, I.; de Messieres, G.; Drosback, M.; Gugliucci, N.; Jackson, L.; Lynch, R.; Romero, C.; Sivakoff, G.; Whelan, D.; Wong, A.

2010-10-01

Dark Skies, Bright Kids (DSBK) is an educational/public outreach program at the University of Virginia directed primarily towards rural elementary school students in grades 3-5. The program, which is run by a diverse community of volunteers (faculty, postdocs, grad students, and undergrads), targets schools in the rural areas surrounding UVa in southern Albemarle County. While these schools are privileged with remarkably dark skies, these same schools are also home to an economically under-privileged and educationally under-served population. DSBK seeks to use those dark skies, among other resources, to create excitement and interest in science and engineering as part of a weekly after-school program. A typical afternoon consists of 1.5-2.5 hours of science activities specifically centered around space and astronomy. Each week has a theme (e.g., rockets, invisible light) and we incorporate a mix of activities on that theme, such as hands-on experiments, stories, games, and creative play. We also encourage family involvement, so that the parents are actively involved in their children's education. Every other week, we hold a family observing night, so both the students and their parents can learn about the night sky together. The program lasts for one semester at each school, and we have just completed our second semester of work. Each new semester brings on new challenges, but also new lessons to make our program better in future semesters. Our group actively writes and then rewrites our own lesson plans as we learn what works best with the students. We are now in the process of putting our lesson plans online so other groups can take advantage of what we have learned and apply this program at other schools. On the web: http://www.astro.virginia.edu/dsbk/

All-Sky Observational Evidence for An Inverse Correlation Between Dust Temperature and Emissivity Spectral Index

NASA Technical Reports Server (NTRS)

Liang, Z.; Fixsen, D. J.; Gold, B.

2012-01-01

We show that a one-component variable-emissivity-spectral-index model (the free- model) provides more physically motivated estimates of dust temperature at the Galactic polar caps than one- or two-component fixed-emissivity-spectral-index models (fixed- models) for interstellar dust thermal emission at far-infrared and millimeter wavelengths. For the comparison we have fit all-sky one-component dust models with fixed or variable emissivity spectral index to a new and improved version of the 210-channel dust spectra from the COBE-FIRAS, the 100-240 micrometer maps from the COBE-DIRBE and the 94 GHz dust map from the WMAP. The best model, the free-alpha model, is well constrained by data at 60-3000 GHz over 86 per cent of the total sky area. It predicts dust temperature (T(sub dust)) to be 13.7-22.7 (plus or minus 1.3) K, the emissivity spectral index (alpha) to be 1.2-3.1 (plus or minus 0.3) and the optical depth (tau) to range 0.6-46 x 10(exp -5) with a 23 per cent uncertainty. Using these estimates, we present all-sky evidence for an inverse correlation between the emissivity spectral index and dust temperature, which fits the relation alpha = 1/(delta + omega (raised dot) T(sub dust) with delta = -.0.510 plus or minus 0.011 and omega = 0.059 plus or minus 0.001. This best model will be useful to cosmic microwave background experiments for removing foreground dust contamination and it can serve as an all-sky extended-frequency reference for future higher resolution dust models.

A Comparison of Maps and Power Spectra Determined from South Pole Telescope and Planck Data

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

Hou, Z.; Aylor, K.; Benson, B. A.

We study the consistency of 150 GHz data from the South Pole Telescope (SPT) and 143 GHz data from the Planck satellite over the patch of sky covered by the SPT-SZ survey. Here, we first visually compare the maps and find that the residuals appear consistent with noise after accounting for differences in angular resolution and filtering. We then calculate (1) the cross-spectrum between two independent halves of SPT data, (2) the cross-spectrum between two independent halves of Planck data, and (3) the cross-spectrum between SPT and Planck data. We find that the three cross-spectra are well fit (PTE =more » 0.30) by the null hypothesis in which both experiments have measured the same sky map up to a single free calibration parameter—i.e., we find no evidence for systematic errors in either data set. As a by-product, we improve the precision of the SPT calibration by nearly an order of magnitude, from 2.6% to 0.3% in power. Finally, we compare all three cross-spectra to the full-sky Planck power spectrum and find marginal evidence for differences between the power spectra from the SPT-SZ footprint and the full sky. We model these differences as a power law in spherical harmonic multipole number. The best-fit value of this tilt is consistent among the three cross-spectra in the SPT-SZ footprint, implying that the source of this tilt is a sample variance fluctuation in the SPT-SZ region relative to the full sky. Lastly, the consistency of cosmological parameters derived from these data sets is discussed in a companion paper.« less

Google Sky: A Digital View of the Night Sky

NASA Astrophysics Data System (ADS)

Connolly, A. Scranton, R.; Ornduff, T.

2008-11-01

From its inception Astronomy has been a visual science, from careful observations of the sky using the naked eye, to the use of telescopes and photographs to map the distribution of stars and galaxies, to the current era of digital cameras that can image the sky over many decades of the electromagnetic spectrum. Sky in Google Earth (http://earth.google.com) and Google Sky (http://www.google.com/sky) continue this tradition, providing an intuitive visual interface to some of the largest astronomical imaging surveys of the sky. Streaming multi-color imagery, catalogs, time domain data, as well as annotating interesting astronomical sources and events with placemarks, podcasts and videos, Sky provides a panchromatic view of the universe accessible to anyone with a computer. Beyond a simple exploration of the sky Google Sky enables users to create and share content with others around the world. With an open interface available on Linux, Mac OS X and Windows, and translations of the content into over 20 different languages we present Sky as the embodiment of a virtual telescope for discovery and sharing the excitement of astronomy and science as a whole.

A New Method to Cross Calibrate and Validate TOMS, SBUV/2, and SCIAMACHY Measurements

NASA Technical Reports Server (NTRS)

Ahmad, Ziauddin; Hilsenrath, Ernest; Einaudi, Franco (Technical Monitor)

2001-01-01

A unique method to validate back scattered ultraviolet (buv) type satellite data that complements the measurements from existing ground networks is proposed. The method involves comparing the zenith sky radiance measurements from the ground to the nadir radiance measurements taken from space. Since the measurements are compared directly, the proposed method is superior to any other method that involves comparing derived products (for example, ozone), because comparison of derived products involve inversion algorithms which are susceptible to several type of errors. Forward radiative transfer (RT) calculations show that for an aerosol free atmosphere, the ground-based zenith sky radiance measurement and the satellite nadir radiance measurements can be predicted with an accuracy of better than 1 percent. The RT computations also show that for certain values of the solar zenith angles, the radiance comparisons could be better than half a percent. This accuracy is practically independent of ozone amount and aerosols in the atmosphere. Experiences with the Shuttle Solar Backscatter Ultraviolet (SSBUV) program show that the accuracy of the ground-based zenith sky radiance measuring instrument can be maintained at a level of a few tenth of a percent. This implies that the zenith sky radiance measurements can be used to validate Total Ozone Mapping Spectrometer (TOMS), Solar Backscatter Ultraviolet (SBUV/2), and The SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY) radiance data. Also, this method will help improve the long term precision of the measurements for better trend detection and the accuracy of other BUV products such as tropospheric ozone and aerosols. Finally, in the long term, this method is a good candidate to inter-calibrate and validate long term observations of upcoming operational instruments such as Global Ozone Monitoring Experiment (GOME-2), Ozone Mapping Instrument (OMI), Ozone Dynamics Ultraviolet Spectrometer (ODUS), and Ozone Mapping and Profiler Suite (OMPS).

SkyServer Voyages Website - Using Big Data to Explore Astronomy Concepts in Formal Education Settings

NASA Astrophysics Data System (ADS)

Meredith, Kate K.; Masters, Karen; Raddick, Jordan; Lundgren, Britt

2015-08-01

The Sloan Digital Sky Survey (SDSS) web interface “SkyServer” has long included online educational materials designed to help students and the public discover the fundamentals of modern astronomy using real observations from the SDSS database. The newly launched SDSS Voyages website updates and expands these activities to reflect new data from subsequent generations of the survey, advances in web technology, and evolving practices in science education. Voyages provides access to quality astronomy, astrophysics, and engineering materials to educators seeking an inquiry approach to fundamental concepts. During this session we will provide an overview of the design and development of Skyserver Voyages and discuss ways to apply this resource at K-12 and university levels.

New features to the night sky radiance model illumina: Hyperspectral support, improved obstacles and cloud reflection

NASA Astrophysics Data System (ADS)

Aubé, M.; Simoneau, A.

2018-05-01

Illumina is one of the most physically detailed artificial night sky brightness model to date. It has been in continuous development since 2005 [1]. In 2016-17, many improvements were made to the Illumina code including an overhead cloud scheme, an improved blocking scheme for subgrid obstacles (trees and buildings), and most importantly, a full hyperspectral modeling approach. Code optimization resulted in significant reduction in execution time enabling users to run the model on standard personal computers for some applications. After describing the new schemes introduced in the model, we give some examples of applications for a peri-urban and a rural site both located inside the International Dark Sky reserve of Mont-Mégantic (QC, Canada).

A New Sky Brightness Monitor

NASA Astrophysics Data System (ADS)

Crawford, David L.; McKenna, D.

2006-12-01

A good estimate of sky brightness and its variations throughout the night, the months, and even the years is an essential bit of knowledge both for good observing and especially as a tool in efforts to minimize sky brightness through local action. Hence a stable and accurate monitor can be a valuable and necessary tool. We have developed such a monitor, with the financial help of Vatican Observatory and Walker Management. The device is now undergoing its Beta test in preparation for production. It is simple, accurate, well calibrated, and automatic, sending its data directly to IDA over the internet via E-mail . Approximately 50 such monitors will be ready soon for deployment worldwide including most major observatories. Those interested in having one should enquire of IDA about details.

Comparison of ScaRaB, GOES 8, Aircraft, and Surface Observations of the Absorption of Solar Radiation by Clouds

NASA Technical Reports Server (NTRS)

Pope, Shelly K.; Valero, Francisco P. J.; Collins, William D.; Minnis, Patrick

2002-01-01

Data obtained by the Scanner for Radiation Budget (ScaRaB) instrument on the Meteor 3 satellite have been analyzed and compared to satellite (GOES 8), aircraft (Radiation Measurement System, RAMS), and surface (Baseline Solar Radiation Network (BSRN), Solar and Infrared Observations System (SIROS), and RAMS) measurements of irradiance obtained during the Atmospheric Radiation Measurements Enhanced Shortwave Experiment (ARESE). It is found that the ScaRaB data covering the period from March 1994 to February 1995 (the instrument's operational lifetime) indicate excess absorption of solar radiation by the cloudy atmosphere in agreement with previous aircraft, surface, and GOES 8 results. The full ScaRaB data set combined with BSRN and SIROS surface observations gives an average all-sky absorptance of 0.28. The GOES 8 data set combined with RAMS surface observations gives an average all-sky absorptance of 0.26. The aircraft data set (RAMS) gives a mean all-sky absorptance of 0.24 (for the column between 0.5 and 13 km).

Infrared small target detection in heavy sky scene clutter based on sparse representation

NASA Astrophysics Data System (ADS)

Liu, Depeng; Li, Zhengzhou; Liu, Bing; Chen, Wenhao; Liu, Tianmei; Cao, Lei

2017-09-01

A novel infrared small target detection method based on sky clutter and target sparse representation is proposed in this paper to cope with the representing uncertainty of clutter and target. The sky scene background clutter is described by fractal random field, and it is perceived and eliminated via the sparse representation on fractal background over-complete dictionary (FBOD). The infrared small target signal is simulated by generalized Gaussian intensity model, and it is expressed by the generalized Gaussian target over-complete dictionary (GGTOD), which could describe small target more efficiently than traditional structured dictionaries. Infrared image is decomposed on the union of FBOD and GGTOD, and the sparse representation energy that target signal and background clutter decomposed on GGTOD differ so distinctly that it is adopted to distinguish target from clutter. Some experiments are induced and the experimental results show that the proposed approach could improve the small target detection performance especially under heavy clutter for background clutter could be efficiently perceived and suppressed by FBOD and the changing target could also be represented accurately by GGTOD.

Correction of the Temperature Effect in 1020 NM Band of Sun-Sky Radiometer

NASA Astrophysics Data System (ADS)

Li, K.; Li, Z.; Li, D.; Xie, Y.; Xu, H.

2018-04-01

Aerosol is an important part of the earth-atmosphere system. It can directly and indirectly influence solar radiation and then affect the energy balance of earth-atmosphere system. AERONET, as the largest ground-based observation network, provides multi-parameters of aerosol from more than 600 hundred sites using sun-sky radiometer, which contains 9 channels from 340 nm to 1640 nm. Among which, 1020 nm channel is greatly influenced by the temperature. In this paper, a new correction method of 1020 nm band is introduced. The new method transfers the temperature correction coefficient of the master radiometer to the comparative one. The filed calibration experiment shown that the temperature correction coefficient obtained by this method is close to the result from the temperature controlled chamber, and the difference is about 2.1 %. This new method is easy-to-use, and its accuracy is comparable to the standard one. It is more applicable for large-scale instrument calibration. In principle, this method is applicable to all bands of the sun-sky radiometer.

Engaging Scientists in Meaningful E/PO: The Universe Discovery Guides

NASA Astrophysics Data System (ADS)

Meinke, B. K.; Lawton, B.; Gurton, S.; Smith, D. A.; Manning, J. G.

2014-12-01

For the 2009 International Year of Astronomy, the then-existing NASA Origins Forum collaborated with the Astronomical Society of the Pacific (ASP) to create a series of monthly "Discovery Guides" for informal educator and amateur astronomer use in educating the public about featured sky objects and associated NASA science themes. Today's NASA Astrophysics Science Education and Public Outreach Forum (SEPOF), one of a new generation of forums coordinating the work of NASA Science Mission Directorate (SMD) EPO efforts—in collaboration with the ASP and NASA SMD missions and programs--has adapted the Discovery Guides into "evergreen" educational resources suitable for a variety of audiences. The Guides focus on "deep sky" objects and astrophysics themes (stars and stellar evolution, galaxies and the universe, and exoplanets), showcasing EPO resources from more than 30 NASA astrophysics missions and programs in a coordinated and cohesive "big picture" approach across the electromagnetic spectrum, grounded in best practices to best serve the needs of the target audiences. Each monthly guide features a theme and a representative object well-placed for viewing, with an accompanying interpretive story, finding charts, strategies for conveying the topics, and complementary supporting NASA-approved education activities and background information from a spectrum of NASA missions and programs. The Universe Discovery Guides are downloadable from the NASA Night Sky Network web site at nightsky.jpl.nasa.gov. We will share the Forum-led Collaborative's experience in developing the guides, how they place individual science discoveries and learning resources into context for audiences, and how the Guides can be readily used in scientist public outreach efforts, in college and university introductory astronomy classes, and in other engagements between scientists, students and the public.

Three gangliogliomas: results of GTG-banding, SKY, genome-wide high resolution SNP-array, gene expression and review of the literature.

PubMed

Xu, Li-Xin; Holland, Heidrun; Kirsten, Holger; Ahnert, Peter; Krupp, Wolfgang; Bauer, Manfred; Schober, Ralf; Mueller, Wolf; Fritzsch, Dominik; Meixensberger, Jürgen; Koschny, Ronald

2015-04-01

According to the World Health Organization gangliogliomas are classified as well-differentiated and slowly growing neuroepithelial tumors, composed of neoplastic mature ganglion and glial cells. It is the most frequent tumor entity observed in patients with long-term epilepsy. Comprehensive cytogenetic and molecular cytogenetic data including high-resolution genomic profiling (single nucleotide polymorphism (SNP)-array) of gangliogliomas are scarce but necessary for a better oncological understanding of this tumor entity. For a detailed characterization at the single cell and cell population levels, we analyzed genomic alterations of three gangliogliomas using trypsin-Giemsa banding (GTG-banding) and by spectral karyotyping (SKY) in combination with SNP-array and gene expression array experiments. By GTG and SKY, we could confirm frequently detected chromosomal aberrations (losses within chromosomes 10, 13 and 22; gains within chromosomes 5, 7, 8 and 12), and identify so far unknown genetic aberrations like the unbalanced non-reciprocal translocation t(1;18)(q21;q21). Interestingly, we report on the second so far detected ganglioglioma with ring chromosome 1. Analyses of SNP-array data from two of the tumors and respective germline DNA (peripheral blood) identified few small gains and losses and a number of copy-neutral regions with loss of heterozygosity (LOH) in germline and in tumor tissue. In comparison to germline DNA, tumor tissues did not show substantial regions with significant loss or gain or with newly developed LOH. Gene expression analyses of tumor-specific genes revealed similarities in the profile of the analyzed samples regarding different relevant pathways. Taken together, we describe overlapping but also distinct and novel genetic aberrations of three gangliogliomas. © 2014 Japanese Society of Neuropathology.

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.

The Quality Lighting Teaching Kit: Educating the Public about the Dark Side of IYL2015

NASA Astrophysics Data System (ADS)

Walker, Constance Elaine; Pompea, Stephen M.; Levy, Rebecca

2015-08-01

The UN-sanctioned International Year of Light in 2015 (IYL2015) is providing an opportunity to increase public awareness of dark skies preservation, quality lighting and energy conservation. The Education and Public Outreach (EPO) group at the U.S. National Optical Astronomy Observatory (NOAO) has received a grant through the IAU to produce official “Quality Lighting Teaching Kits” for the IYL2015 cornerstone theme, “Cosmic Light”. These kits will emphasize the use of proper optical design in achieving quality lighting that promotes both energy efficiency and energy conservation of an endangered natural resource: our dark skies. Poor quality lighting not only impedes astronomy research, but creates safety issues, affects human circadian sensitivities, disrupts ecosystems, and wastes billions of dollars/year in energy consumption and carbon emissions.The concepts and practices of “quality lighting” will be explored through problem-based learning (e.g., engineering design), hands-on/minds-on activities, demonstrations, and formative and summative assessment probes. The impact of the kits will be amplified by providing professional development using tutorial videos created at NOAO and conducting question and answer sessions via Google+ Hangouts for program participants. The Quality Lighting Teaching Kit will leverage ten years of work by NOAO’s EPO team in developing programs on lighting and optics education (e.g., the NSF-funded “Hands on Optics”, IAU “Dark Skies Africa” and Arizona Public Service Foundation’s “Dark Skies Yuma” programs).NOAO’s partners are the International Society for Optics and Photonics (SPIE), International Commission on Illumination (CIE), International Dark-Sky Association (IDA), and IAU Office of Astronomy for Development, with sponsorship from the IAU and The Optical Society (OSA). Along with astronomy education centers (NUCLIO and Universe Awareness), the networks will disseminate kits to formal and informal audiences worldwide. The impact sought is a change in knowledge, attitude, and behavior in each community by learning how to light responsibly, improving the quality of life in “illuminating” ways.

A numerical experiment on light pollution from distant sources

NASA Astrophysics Data System (ADS)

Kocifaj, M.

2011-08-01

To predict the light pollution of the night-time sky realistically over any location or measuring point on the ground presents quite a difficult calculation task. Light pollution of the local atmosphere is caused by stray light, light loss or reflection of artificially illuminated ground objects or surfaces such as streets, advertisement boards or building interiors. Thus it depends on the size, shape, spatial distribution, radiative pattern and spectral characteristics of many neighbouring light sources. The actual state of the atmospheric environment and the orography of the surrounding terrain are also relevant. All of these factors together influence the spectral sky radiance/luminance in a complex manner. Knowledge of the directional behaviour of light pollution is especially important for the correct interpretation of astronomical observations. From a mathematical point of view, the light noise or veil luminance of a specific sky element is given by a superposition of scattered light beams. Theoretical models that simulate light pollution typically take into account all ground-based light sources, thus imposing great requirements on CPU and MEM. As shown in this paper, a contribution of distant sources to the light pollution might be essential under specific conditions of low turbidity and/or Garstang-like radiative patterns. To evaluate the convergence of the theoretical model, numerical experiments are made for different light sources, spectral bands and atmospheric conditions. It is shown that in the worst case the integration limit is approximately 100 km, but it can be significantly shortened for light sources with cosine-like radiative patterns.

Polarization of 'water-skies' above arctic open waters: how polynyas in the ice-cover can be visually detected from a distance.

PubMed

Hegedüs, Ramón; Akesson, Susanne; Horváth, Gábor

2007-01-01

The foggy sky above a white ice-cover and a dark water surface (permanent polynya or temporary lead) is white and dark gray, phenomena called the 'ice-sky' and the 'water-sky,' respectively. Captains of icebreaker ships used to search for not-directly-visible open waters remotely on the basis of the water sky. Animals depending on open waters in the Arctic region may also detect not-directly-visible waters from a distance by means of the water sky. Since the polarization of ice-skies and water-skies has not, to our knowledge, been studied before, we measured the polarization patterns of water-skies above polynyas in the arctic ice-cover during the Beringia 2005 Swedish polar research expedition to the North Pole region. We show that there are statistically significant differences in the angle of polarization between the water-sky and the ice-sky. This polarization phenomenon could help biological and man-made sensors to detect open waters not directly visible from a distance. However, the threshold of polarization-based detection would be rather low, because the degree of linear polarization of light radiated by water-skies and ice-skies is not higher than 10%.

Spectral karyotyping (SKY) analysis of heritable effects of radiation-induced malignant transformation

NASA Astrophysics Data System (ADS)

Zitzelsberger, Horst; Fung, Jingly; Janish, C.; McNamara, George; Bryant, P. E.; Riches, A. C.; Weier, Heinz-Ulli G.

1999-05-01

Radiocarcinogenesis is widely recognized as occupational, environmental and therapeutical hazard, but the underlying mechanisms and cellular targets have not yet been identified. We applied SKY to study chromosomal rearrangements leading to malignant transformation of irradiated thyroid epithelial cells. SKY is a recently developed technique to detect translocations involving non-homologous based on unique staining of all 24 human chromosomes by hybridization with a mixture of whole chromosome painting probes. A tuneable interferometer mounted on a fluorescence microscope in front of a CCD camera allows to record the 400 nm - 1000 nm fluorescence spectrum for each pixel in the image. After background correction, spectra recorded for each pixel are compared to reference spectra stored previously for each chromosome-specific probe. Thus, pixel spectra can be associated with specific chromosomes and displayed in 'classification' colors, which are defined so that even small translocations become readily discernible. SKY analysis was performed on several radiation-transformed cell lines. Line S48T was generated from a primary tumor of a child exposed to elevated levels of radiation following the Chernobyl nuclear accident. Subclones were generated from the human thyroid epithelial cell line (HTori-3) by exposure to gamma or alpha irradiation. SKY analysis revealed multiple translocations and, combined with G-banding, allowed the definition of targets for positional cloning of tumor related genes.

Topographic Correction Module at Storm (TC@Storm)

NASA Astrophysics Data System (ADS)

Zaksek, K.; Cotar, K.; Veljanovski, T.; Pehani, P.; Ostir, K.

2015-04-01

Different solar position in combination with terrain slope and aspect result in different illumination of inclined surfaces. Therefore, the retrieved satellite data cannot be accurately transformed to the spectral reflectance, which depends only on the land cover. The topographic correction should remove this effect and enable further automatic processing of higher level products. The topographic correction TC@STORM was developed as a module within the SPACE-SI automatic near-real-time image processing chain STORM. It combines physical approach with the standard Minnaert method. The total irradiance is modelled as a three-component irradiance: direct (dependent on incidence angle, sun zenith angle and slope), diffuse from the sky (dependent mainly on sky-view factor), and diffuse reflected from the terrain (dependent on sky-view factor and albedo). For computation of diffuse irradiation from the sky we assume an anisotropic brightness of the sky. We iteratively estimate a linear combination from 10 different models, to provide the best results. Dependent on the data resolution, we mask shades based on radiometric (image) or geometric properties. The method was tested on RapidEye, Landsat 8, and PROBA-V data. Final results of the correction were evaluated and statistically validated based on various topography settings and land cover classes. Images show great improvements in shaded areas.

A fibre optic, four channel comparative photometer

NASA Technical Reports Server (NTRS)

Walker, E. N.

1988-01-01

Development of a four channel comparative photometer is described. Tests have shown that it is stable from night to night and is capable of working in very poor sky conditions. Even when the sky conditions are so poor that stars are barely visible, light curves can still be obtained with an r.m.s. value of 0.0016 mag., provided that integration times that are long compared with the transparancy changes are possible.

Sunset over Twin Peaks

NASA Technical Reports Server (NTRS)

1997-01-01

This image was taken by the Imager for Mars Pathfinder (IMP) about one minute after sunset on Mars on Sol 21. The prominent hills dubbed 'Twin Peaks' form a dark silhouette at the horizon, while the setting sun casts a pink glow over the darkening sky. The image was taken as part of a twilight study which indicates how the brightness of the sky fades with time after sunset. Scientists found that the sky stays bright for up to two hours after sunset, indicating that Martian dust extends very high into the atmosphere.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

Skylab

NASA Image and Video Library

1972-12-21

Hans F. Wuenscher, assistant director for Advanced Space Projects Engineering Laboratory at Marshall Space Flight Center (MSFC), examined the facility to be used by Skylab astronauts in performing a number of experiments in material science and manufacturing in space. The equipment shown here is a duplicate of the M512 Experiment hardware flown in the Multiple Docking Adapter section of the Sky lab. This equipment, itself an experiment, was be used for conducting 5 other experiments in the round vacuum chamber. Inside was a cavity which held the M518 Multipurpose Electric Furnace, a facility which was used for conducting other experiments. In all, a total of 17 experiments were conducted using this facility and furnace.

Preparing for the Eclipse

ERIC Educational Resources Information Center

Hurst, Anna; Plummer, Julia; Gurton, Suzanne; Schatz, Dennis

2017-01-01

On August 21, 2017, sky gazers all across North America will experience a total solar eclipse, arguably the most breathtaking of all astronomical phenomena. The August eclipse is an ideal astronomical event to observe with young children because it allows them to observe a powerful and easily accessible astronomical phenomenon. Observing…

A look at the "Luminous sphere"

NASA Astrophysics Data System (ADS)

Yeghiazaryan, Ani

2015-07-01

Hovhannes Toumanyan's watchful eye was fascinated by the mysterious and charming image of the sky since an early childhood. His poetic soul first intuitively, then parallel with the enrichment of his life experience got to know universal luminaries scientifically, became "a universe reader" and the talker of Sirius.

Scientific Experiences Using Argentinean Sounding Rockets in Antarctica

NASA Astrophysics Data System (ADS)

Sánchez-Peña, Miguel

2000-07-01

Argentina in the sixties and seventies, had experience for developing and for using sounding rockets and payloads to perform scientific space experiments. Besides they have several bases in Antarctica with adequate premises and installations, also duly equipped aircrafts and trained crews to flight to the white continent. In February 1965, scientists and technical people from the "Instituto de Investigacion Aeronáutica y Espacial" (I.I.A.E.) with the cooperation of the Air Force and the Tucuman University, conducted the "Matienzo Operation" to measure X radiation and temperature in the upper atmosphere, using the Gamma Centauro rocket and also using big balloons. The people involved in the experience, the launcher, other material and equipment flew from the south tip of Argentina to the Matienzo base in Antarctica, in a C-47 aircraft equipped with skies an additional jet engine Marbore 2-C. Other experience was performed in 1975 in the "Marambio" Antartic Base, using the two stages solid propellent sounding rocket Castor, developed in Argentina. The payload was developed in cooperation with the Max Planck Institute of Germany. It consist of a special mixture including a shape charge to form a ionized cloud producing a jet of electrons travelling from Marambio base to the conjugate point in the Northern hemisphere. The cloud was observed by several ground stations in Argentina and also by a NASA aircraft with TV cameras, flying at East of New York. The objective of this experience was to study the electric and magnetic fields in altitude, the neutral points, the temperature and electrons profile. The objectives of both experiments were accomplished satisfactorily.

Infrared Sky Imager (IRSI) Instrument Handbook

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

Morris, Victor R.

2016-04-01

The Infrared Sky Imager (IRSI) deployed at the Atmospheric Radiation Measurement (ARM) Climate Research Facility is a Solmirus Corp. All Sky Infrared Visible Analyzer. The IRSI is an automatic, continuously operating, digital imaging and software system designed to capture hemispheric sky images and provide time series retrievals of fractional sky cover during both the day and night. The instrument provides diurnal, radiometrically calibrated sky imagery in the mid-infrared atmospheric window and imagery in the visible wavelengths for cloud retrievals during daylight hours. The software automatically identifies cloudy and clear regions at user-defined intervals and calculates fractional sky cover, providing amore » real-time display of sky conditions.« less

A bolt out of the blue.

PubMed

Dwyer, Joseph R

2005-05-01

Lightning is a particularly unsettling product of bad weather. It causes more deaths and injuries in the U.S. than either hurricanes or tornadoes do, and it strikes without warning, sometimes with nothing but blue sky overhead. In central Florida, where I live, thunderstorms are a daily occurrence during the summer, and so, ironically, people in the Sunshine State often spend their afternoons indoors to avoid the risk of death from the sky. Worldwide, lightning flashes about four million times a day, and bolts have even been observed on other planets. Yet despite its familiarity, we still do not know what causes lightning. It is a misconception that Benjamin Franklin solved the puzzle when he conducted his famous kite experiment in 1752.

Summaries of SpS17 Discussions IAU GA 2012 Special Session on Light Pollution

NASA Astrophysics Data System (ADS)

Walker, Constance E.; Parks, Bob; McKenna, Dan; Sefako, Ramotholo; Smith, Malcolm; Galadí-Enríquez, David

2015-03-01

To address light pollution issues, IAU Commissions 41, 46, 50, and 55 are involved in getting the word out to the public and IAU members via cultural, educational, technical; however, efforts can always improve and evolve. To carry out a successful light pollution abatement program supported by the IAU, it takes a diversity of groups, professions, and disciplines with their collective knowledge and experience. In manifesting dark skies awareness effectively, we are stronger together than we are alone; therefore, combining efforts of Commissions 41, 46, 50 and 55 with organizations like the International Dark-Sky Association, Astronomers Without Borders, The World at Night and partnering with events like Earth Hour or GLOBE at Night is a good step forward.

An Automatic Cloud Mask Algorithm Based on Time Series of MODIS Measurements

NASA Technical Reports Server (NTRS)

Lyapustin, Alexei; Wang, Yujie; Frey, R.

2008-01-01

Quality of aerosol retrievals and atmospheric correction depends strongly on accuracy of the cloud mask (CM) algorithm. The heritage CM algorithms developed for AVHRR and MODIS use the latest sensor measurements of spectral reflectance and brightness temperature and perform processing at the pixel level. The algorithms are threshold-based and empirically tuned. They don't explicitly address the classical problem of cloud search, wherein the baseline clear-skies scene is defined for comparison. Here, we report on a new CM algorithm which explicitly builds and maintains a reference clear-skies image of the surface (refcm) using a time series of MODIS measurements. The new algorithm, developed as part of the Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm for MODIS, relies on fact that clear-skies images of the same surface area have a common textural pattern, defined by the surface topography, boundaries of rivers and lakes, distribution of soils and vegetation etc. This pattern changes slowly given the daily rate of global Earth observations, whereas clouds introduce high-frequency random disturbances. Under clear skies, consecutive gridded images of the same surface area have a high covariance, whereas in presence of clouds covariance is usually low. This idea is central to initialization of refcm which is used to derive cloud mask in combination with spectral and brightness temperature tests. The refcm is continuously updated with the latest clear-skies MODIS measurements, thus adapting to seasonal and rapid surface changes. The algorithm is enhanced by an internal dynamic land-water-snow classification coupled with a surface change mask. An initial comparison shows that the new algorithm offers the potential to perform better than the MODIS MOD35 cloud mask in situations where the land surface is changing rapidly, and over Earth regions covered by snow and ice.

Comparing Planck and WMAP: Maps, Spectra, and Parameters

NASA Astrophysics Data System (ADS)

Larson, D.; Weiland, J. L.; Hinshaw, G.; Bennett, C. L.

2015-03-01

We examine the consistency of the 9 yr WMAP data and the first-release Planck data. We specifically compare sky maps, power spectra, and the inferred Λ cold dark matter (ΛCDM) cosmological parameters. Residual dipoles are seen in the WMAP and Planck sky map differences, but their amplitudes are consistent within the quoted uncertainties, and they are not large enough to explain the widely noted differences in angular power spectra at higher l. We remove the residual dipoles and use templates to remove residual Galactic foregrounds; after doing so, the residual difference maps exhibit a quadrupole and other large-scale systematic structure. We identify this structure as possibly originating from Planck’s beam sidelobe pick-up, but note that it appears to have insignificant cosmological impact. We develop an extension of the internal linear combination technique to find the minimum-variance difference between the WMAP and Planck sky maps; again we find features that plausibly originate in the Planck data. Lacking access to the Planck time-ordered data we cannot further assess these features. We examine ΛCDM model fits to the angular power spectra and conclude that the ˜2.5% difference in the spectra at multipoles greater than l˜ 100 is significant at the 3-5σ level, depending on how beam uncertainties are handled in the data. We revisit the analysis of WMAP’s beam data to address the power spectrum differences and conclude that previously derived uncertainties are robust and cannot explain the power spectrum differences. In fact, any remaining WMAP errors are most likely to exacerbate the difference. Finally, we examine the consistency of the ΛCDM parameters inferred from each data set taking into account the fact that both experiments observe the same sky, but cover different multipole ranges, apply different sky masks, and have different noise. We find that, while individual parameter values agree within the uncertainties, the six parameters taken together are discrepant at the ˜6σ level, with {χ }2}=56 for 6 degrees of freedom (probability to exceed, PTE = 3× {{10}-10}). The nature of this discrepancy is explored: of the six parameters, {{χ }2} is best improved by marginalizing over {{{Ω}c}{{h}2}, giving {χ }2}=5.2 for 5 degrees of freedom. As an exercise, we find that perturbing the WMAP window function by its dominant beam error profile has little effect on {{{Ω}c}{{h}2}, while perturbing the Planck window function by its corresponding error profile has a much greater effect on {{Ω}c}{{h}2}.

Retrieval of tropospheric carbon monoxide for the MOPITT experiment

NASA Astrophysics Data System (ADS)

Pan, Liwen; Gille, John C.; Edwards, David P.; Bailey, Paul L.; Rodgers, Clive D.

1998-12-01

A retrieval method for deriving the tropospheric carbon monoxide (CO) profile and column amount under clear sky conditions has been developed for the Measurements of Pollution In The Troposphere (MOPITT) instrument, scheduled for launch in 1998 onboard the EOS-AM1 satellite. This paper presents a description of the method along with analyses of retrieval information content. These analyses characterize the forward measurement sensitivity, the contribution of a priori information, and the retrieval vertical resolution. Ensembles of tropospheric CO profiles were compiled both from aircraft in situ measurements and from chemical model results and were used in retrieval experiments to characterize the method and to study the sensitivity to different parameters. Linear error analyses were carried out in parallel with the ensemble experiments. Results of these experiments and analyses indicate that MOPITT CO column measurements will have better than 10% precision, and CO profile measurement will have approximately three pieces of independent information that will resolve 3-5 tropospheric layers to approximately 10% precision. These analyses are important for understanding MOPITT data, both for application of data in tropospheric chemistry studies and for comparison with in situ measurements.

New gridded database of clear-sky solar radiation derived from ground-based observations over Europe

NASA Astrophysics Data System (ADS)

Bartok, Blanka; Wild, Martin; Sanchez-Lorenzo, Arturo; Hakuba, Maria Z.

2017-04-01

Since aerosols modify the entire energy balance of the climate system through different processes, assessments regarding aerosol multiannual variability are highly required by the climate modelling community. Because of the scarcity of long-term direct aerosol measurements, the retrieval of aerosol data/information from other type of observations or satellite measurements are very relevant. One approach frequently used in the literature is analyze of the clear-sky solar radiation which offer a better overview of changes in aerosol content. In the study first two empirical methods are elaborated in order to separate clear-sky situations from observed values of surface solar radiation available at the World Radiation Data Center (WRDC), St. Petersburg. The daily data has been checked for temporal homogeneity by applying the MASH method (Szentimrey, 2003). In the first approach, clear sky situations are detected based on clearness index, namely the ratio of the surface solar radiation to the extraterrestrial solar irradiation. In the second approach the observed values of surface solar radiation are compared to the climatology of clear-sky surface solar radiation calculated by the MAGIC radiation code (Muller et al. 2009). In both approaches the clear-sky radiation values highly depend on the applied thresholds. In order to eliminate this methodological error a verification of clear-sky detection is envisaged through a comparison with the values obtained by a high time resolution clear-sky detection and interpolation algorithm (Long and Ackermann, 2000) making use of the high quality data from the Baseline Surface Radiation Network (BSRN). As the consequences clear-sky data series are obtained for 118 European meteorological stations. Next a first attempt has been done in order to interpolate the point-wise clear-sky radiation data by applying the MISH (Meteorological Interpolation based on Surface Homogenized Data Basis) method for the spatial interpolation of surface meteorological elements developed at the Hungarian Meteorological Service (Szentimrey 2007). In this way new gridded database of clear-sky solar radiation is created suitable for further investigations regarding the role of aerosols in the energy budget, and also for validations of climate model outputs. References 1. Long CN, Ackerman TP. 2000. Identification of clear skies from broadband pyranometer measurements and calculation of downwelling shortwave cloud effects, J. Geophys. Res., 105(D12), 15609-15626, doi:10.1029/2000JD900077. 2. Mueller R, Matsoukas C, Gratzki A, Behr H, Hollmann R. 2009. The CM-SAF operational scheme for the satellite based retrieval of solar surface irradiance - a LUT based eigenvector hybrid approach, Remote Sensing of Environment, 113 (5), 1012-1024, doi:10.1016/j.rse.2009. 01.012 3. Szentimrey T. 2014. Multiple Analysis of Series for Homogenization (MASHv3.03), Hungarian Meteorological Service, https://www.met.hu/en/omsz/rendezvenyek/homogenization_and_interpolation/software/ 4. Szentimrey T. Bihari Z. 2014: Meteorological Interpolation based on Surface Homogenized Data Basis (MISHv1.03) https://www.met.hu/en/omsz/rendezvenyek/homogenization_and_interpolation/software/

Mechanical Design and Development of TES Bolometer Detector Arrays for the Advanced ACTPol Experiment

NASA Technical Reports Server (NTRS)

Ward, Jonathan T.; Austermann, Jason; Beall, James A.; Choi, Steve K.; Crowley, Kevin T.; Devlin, Mark J.; Duff, Shannon M.; Gallardo, Patricio M.; Henderson, Shawn W.; Ho, Shuay-Pwu Patty;

Mechanical designs and development of TES bolometer detector arrays for the Advanced ACTPol experiment

NASA Astrophysics Data System (ADS)

Ward, Jonathan T.; Austermann, Jason; Beall, James A.; Choi, Steve K.; Crowley, Kevin T.; Devlin, Mark J.; Duff, Shannon M.; Gallardo, Patricio A.; Henderson, Shawn W.; Ho, Shuay-Pwu Patty; Hilton, Gene; Hubmayr, Johannes; Khavari, Niloufar; Klein, Jeffrey; Koopman, Brian J.; Li, Dale; McMahon, Jeffrey; Mumby, Grace; Nati, Federico; Niemack, Michael D.; Page, Lyman A.; Salatino, Maria; Schillaci, Alessandro; Schmitt, Benjamin L.; Simon, Sara M.; Staggs, Suzanne T.; Thornton, Robert; Ullom, Joel N.; Vavagiakis, Eve M.; Wollack, Edward J.

2016-07-01

The next generation Advanced ACTPol (AdvACT) experiment is currently underway and will consist of four Transition Edge Sensor (TES) bolometer arrays, with three operating together, totaling 5800 detectors on the sky. Building on experience gained with the ACTPol detector arrays, AdvACT will utilize various new technologies, including 150 mm detector wafers equipped with multichroic pixels, allowing for a more densely packed focal plane. Each set of detectors includes a feedhorn array of stacked silicon wafers which form a spline profile leading to each pixel. This is then followed by a waveguide interface plate, detector wafer, back short cavity plate, and backshort cap. Each array is housed in a custom designed structure manufactured from high purity copper and then gold plated. In addition to the detector array assembly, the array package also encloses cryogenic readout electronics. We present the full mechanical design of the AdvACT high frequency (HF) detector array package along with a detailed look at the detector array stack assemblies. This experiment will also make use of extensive hardware and software previously developed for ACT, which will be modified to incorporate the new AdvACT instruments. Therefore, we discuss the integration of all AdvACT arrays with pre-existing ACTPol infrastructure.

The BlueSky Smoke Modeling Framework: Recent Developments

NASA Astrophysics Data System (ADS)

Sullivan, D. C.; Larkin, N.; Raffuse, S. M.; Strand, T.; ONeill, S. M.; Leung, F. T.; Qu, J. J.; Hao, X.

2012-12-01

BlueSky systems—a set of decision support tools including SmartFire and the BlueSky Framework—aid public policy decision makers and scientific researchers in evaluating the air quality impacts of fires. Smoke and fire managers use BlueSky systems in decisions about prescribed burns and wildland firefighting. Air quality agencies use BlueSky systems to support decisions related to air quality regulations. We will discuss a range of recent improvements to the BlueSky systems, as well as examples of applications and future plans. BlueSky systems have the flexibility to accept basic fire information from virtually any source and can reconcile multiple information sources so that duplication of fire records is eliminated. BlueSky systems currently apply information from (1) the National Oceanic and Atmospheric Administration's (NOAA) Hazard Mapping System (HMS), which represents remotely sensed data from the Moderate Resolution Imaging Spectroradiometer (MODIS), Advanced Very High Resolution Radiometer (AVHRR), and Geostationary Operational Environmental Satellites (GOES); (2) the Monitoring Trends in Burn Severity (MTBS) interagency project, which derives fire perimeters from Landsat 30-meter burn scars; (3) the Geospatial Multi-Agency Coordination Group (GeoMAC), which produces helicopter-flown burn perimeters; and (4) ground-based fire reports, such as the ICS-209 reports managed by the National Wildfire Coordinating Group. Efforts are currently underway to streamline the use of additional ground-based systems, such as states' prescribed burn databases. BlueSky systems were recently modified to address known uncertainties in smoke modeling associated with (1) estimates of biomass consumption derived from sparse fuel moisture data, and (2) models of plume injection heights. Additional sources of remotely sensed data are being applied to address these issues as follows: - The National Aeronautics and Space Administration's (NASA) Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis Real-Time (TMPA-RT) data set is being used to improve dead fuel moisture estimates. - EastFire live fuel moisture estimates, which are derived from NASA's MODIS direct broadcast, are being used to improve live fuel moisture estimates. - NASA's Multi-angle Imaging Spectroradiometer (MISR) stereo heights are being used to improve estimates of plume injection heights. Further, the Fire Location and Modeling of Burning Emissions (FLAMBÉ) model was incorporated into the BlueSky Framework as an alternative means of calculating fire emissions. FLAMBÉ directly estimates emissions on the basis of fire detections and radiance measures from NASA's MODIS and NOAA's GOES satellites. (The authors gratefully acknowledge NASA's Applied Sciences Program [Grant Nos. NN506AB52A and NNX09AV76G)], the USDA Forest Service, and the Joint Fire Science Program for their support.)

An optical to IR sky brightness model for the LSST

NASA Astrophysics Data System (ADS)

Yoachim, Peter; Coughlin, Michael; Angeli, George Z.; Claver, Charles F.; Connolly, Andrew J.; Cook, Kem; Daniel, Scott; Ivezić, Željko; Jones, R. Lynne; Petry, Catherine; Reuter, Michael; Stubbs, Christopher; Xin, Bo

2016-07-01

To optimize the observing strategy of a large survey such as the LSST, one needs an accurate model of the night sky emission spectrum across a range of atmospheric conditions and from the near-UV to the near-IR. We have used the ESO SkyCalc Sky Model Calculator1, 2 to construct a library of template spectra for the Chilean night sky. The ESO model includes emission from the upper and lower atmosphere, scattered starlight, scattered moonlight, and zodiacal light. We have then extended the ESO templates with an empirical fit to the twilight sky emission as measured by a Canon all-sky camera installed at the LSST site. With the ESO templates and our twilight model we can quickly interpolate to any arbitrary sky position and date and return the full sky spectrum or surface brightness magnitudes in the LSST filter system. Comparing our model to all-sky observations, we find typical residual RMS values of +/-0.2-0.3 magnitudes per square arcsecond.

Touch the Cosmos: The 2012 International Earth and Sky Photo Contest

NASA Astrophysics Data System (ADS)

Walker, C. E.; Tafreshi, B.; Simmons, M.

2013-04-01

In April 2012, the National Optical Astronomy Observatory in partnership with The World At Night organized the Third International Earth and Sky Photo Contest on the importance of preserving dark skies for the Dark Skies Awareness theme of Global Astronomy Month. At the Fall 2012 ASP conference, a presentation on the Earth and Sky Photo Contest was made. The intended outcomes of the 10-minute oral talk were 1) to inspire visual learners to be more aware of the disappearing starry night sky due to light pollution, 2) to provide some basic understanding of what the issues are surrounding light pollution, 3) to provide incentive to get people to participate in the photo contest as a way of promoting dark skies awareness and 4) to provide a stepping stone to more active involvement in dark skies preservation. With more than half of the world's population in cities, Earth and Sky photos of dark, starry skies offer the next best thing to being there.

Looking toward the Blue Sky: Environmental Education Researchers' Experience, Influences, and Aspirations

ERIC Educational Resources Information Center

Ardoin, Nicole M.; Clark, Charlotte R.; Wojcik, Deborah J.

2016-01-01

Environmental education (EE) researchers hail from diverse disciplines and sociocultural contexts, work in a range of settings, and envision various outcomes. Desiring to better understand their backgrounds, interests, and aspirations for the field, we surveyed EE researchers to explore their theoretical and educational influences and what they…

Elementary Student Knowledge Gains in the Digital Portable Planetarium

ERIC Educational Resources Information Center

Carsten-Conner, Laura D.; Larson, Angela M.; Arseneau, Jennifer; Herrick, Robert R.

2015-01-01

Immersive environments hold promise to provide unique and heightened sensory experiences that focus a learner's attention, and thus may be useful learning platforms. In particular, portable planetariums may be useful in advancing conceptual knowledge about the night sky, because they afford learners with Earth-based views of celestial motions,…

Gamma-ray burst spectroscopy capabilities of the BATSE/GRO experiment

NASA Technical Reports Server (NTRS)

Matteson, J. L.; Fishman, G. J.; Meegan, C. A.; Parnell, T. A.; Wilson, R. B.; Paciesas, W.; Cline, T. L.; Teegarden, B. J.

1985-01-01

A scintillation spectrometer is included in each of the eight BATSE/GRO detector modules, resulting in all-sky coverage for gamma-ray bursts. The scientific motivation, design and capabilities of these spectrometers for performing spectral observations over a wide range of gamma-ray energies and burst intensities are described.

Clear Sky Column Closure Studies of Urban-Marine and Mineral-Dust Aerosols Using Aircraft, Ship, Satellite and Ground-Based Measurements in ACE-2

NASA Technical Reports Server (NTRS)

Schmid, Beat; Russell, Philip B.; Livingston, John M.; Gasso, Santiago; Hegg, Dean A.; Collins, Donald R.; Flagan, Richard C.; Seinfeld, John H.; Oestroem, Elisabeth; Noone, Kevin J.;

Affordable Digital Planetariums with WorldWide Telescope

NASA Astrophysics Data System (ADS)

Rosenfield, P.; Connolly, A.; Fay, J.; Sayres, C.; Tofflemire, B.

2011-09-01

Digital planetariums can provide a broader range of educational experiences than the more classical planetariums that use star-balls. This is because of their ability to project images, content from current research, and the 3-D distribution of the stars and galaxies. While there are hundreds of planetariums in the country, the reason that few of these are fully digital is the cost. In collaboration with Microsoft Research (MSR), we have developed a way to digitize existing planetariums for approximately $40,000 using freely available software. We describe here how off the shelf equipment, together with a WorldWide Telescope client, can provide a rich and truly interactive experience. This will enable students and the public to pan though multi-wavelength full-sky scientific data sets, explore 3-D visualizations of our Solar System (including trajectories of millions of minor planets), near-by stars, and the SDSS galaxy catalog.

Atmospheric Polarization Imaging with Variable Aerosols, Clouds, and Surface Albedo

DTIC Science & Technology

2013-07-01

but partly supported by AFOSR polarization funds); 6. Mr. Gavin Lommatsch – undergraduate student developing NIR polarimetry ; 7. Ms. Elizabeth...grant: 1. J. S. Tyo, D. B. Chenault, J. A. Shaw, D. H. Goldstein, “Techniques in Imaging Polarimetry ,” Chapter 18 in D. H. Goldstein, Polarized Light...A. Barta, J. Gal, B. Suhai, and O. Haiman, “Ground-based full-sky imaging polarimetry of rapidly skies and its use for polarimetric cloud detection

The Competitive Position of Hub Airports in the Transatlantic Market

NASA Technical Reports Server (NTRS)

Burghouwt, Guillaume; Veldhuis, Jan

2006-01-01

This article puts forward the argument that the measurement of connectivity in hub-and-spoke networks has to take into account the quality and quantity of both direct and indirect connections. The NETSCAN model, which has been applied in this study, quantifies indirect connectivity and scales it into a theoretical direct connection. NETSCAN allows researchers, airports, airlines, alliances and airport regions to analyse their competitive position in an integrated way. Using NETSCAN, the authors analysed the developments on the market between northwest Europe and the United States (US) between May 2003 and May 2005. One of the most striking developments has certainly been the impact of the Air France-KLM merger and the effects of the integration of KLM and Northwest into the SkyTeam alliance on the connectivity of Amsterdam Schiphol. Direct as well as indirect connectivity (via European and North American hubs) from Amsterdam to the US increased substantially. The main reason for this increase is the integration of the former Wings and SkyTeam networks via the respective hub airports. Moreover, the extended SkyTeam alliance raised frequencies between Amsterdam and the SkyTeam hubs (Atlanta, Houston, for example), opened new routes (Cincinnati) and boosted the network between Amsterdam and France. As a result of the new routes and frequencies, Amsterdam took over Heathrow s position as the third best-connected northwest European airport to the US.

Semi-physical simulation test for micro CMOS star sensor

NASA Astrophysics Data System (ADS)

Yang, Jian; Zhang, Guang-jun; Jiang, Jie; Fan, Qiao-yun

2008-03-01

A designed star sensor must be extensively tested before launching. Testing star sensor requires complicated process with much time and resources input. Even observing sky on the ground is a challenging and time-consuming job, requiring complicated and expensive equipments, suitable time and location, and prone to be interfered by weather. And moreover, not all stars distributed on the sky can be observed by this testing method. Semi-physical simulation in laboratory reduces the testing cost and helps to debug, analyze and evaluate the star sensor system while developing the model. The test system is composed of optical platform, star field simulator, star field simulator computer, star sensor and the central data processing computer. The test system simulates the starlight with high accuracy and good parallelism, and creates static or dynamic image in FOV (Field of View). The conditions of the test are close to observing real sky. With this system, the test of a micro star tracker designed by Beijing University of Aeronautics and Astronautics has been performed successfully. Some indices including full-sky autonomous star identification time, attitude update frequency and attitude precision etc. meet design requirement of the star sensor. Error source of the testing system is also analyzed. It is concluded that the testing system is cost-saving, efficient, and contributes to optimizing the embed arithmetic, shortening the development cycle and improving engineering design processes.

Monitoring the Low-Energy Gamma-Ray Sky Using Earth Occultation with GLAST GBM

NASA Technical Reports Server (NTRS)

Case, G.; Wilson-Hodge, C.; Cherry, M.; Kippen, M.; Ling, J.; Radocinski, R.; Wheaton, W.

2007-01-01

Long term all-sky monitoring of the 20 keV - 2 MeV gamma-ray sky using the Earth occultation technique was demonstrated by the BATSE instrument on the Compton Gamma Ray Observatory. The principles and techniques used for the development of an end-to-end earth occultation data analysis system for BATSE can be extended to the GLAST Gamma-ray Burst Monitor (GBM), resulting in multiband light curves and time-resolved spectra in the energy range 8 keV to above 1 MeV for known gamma-ray sources and transient outbursts, as well as the discovery of new sources of gamma-ray emission. In this paper we describe the application of the technique to the GBM. We also present the expected sensitivity for the GBM.

Proto-Typing Research Aimed for Secondary School Students and Teachers

NASA Astrophysics Data System (ADS)

Walker, C. E.; Fersch, A.; Barringer, D.; Pompea, S. M.

2011-12-01

In workshops on GLOBE at Night, teacher professional development has begun on using night sky brightness data and bat telemetry data to do scientific research in the classroom. The study looks at the effects of light pollution on the flight paths of threatened and endangered (T&E) bats between their day roosts and night foraging areas. A jump-start in getting secondary school students involved was the BioBlitz event in Tucson, Arizona in October 2011. During the 24-hour event, night Sky Quality Meter (SQM) data was taken across the Saguaro National Park West, through Tucson and across the Saguaro National Park East. The program had its beginning with a pair of Research Experiences for Undergraduates (REU) students and their advisor. Through the collaboration of the National Science Foundation's REU program, the National Optical Astronomy Observatory's GLOBE at Night program and the U.S. Arizona Game and Fish Department (AzGFD), two REU students along with their advisor used data from the GLOBE at Night project and telemetry tracking data of lesser long-nosed bats to study the effects of light pollution on the flight paths of the bats between their day roosts and night foraging areas around the city of Tucson, AZ. During the summer of 2010, the first REU student used the visual limiting magnitude data from GLOBE at Night and, with the assistance of the AzGFD, ran compositional analyses with respect to the bats' flight paths to determine whether the bats were selecting for or against flight through regions of particular night sky brightness levels. The bats selected for the regions in which the limiting sky magnitudes fell between the ranges of 2.8-3.0 to 3.6-3.8 and 4.4-4.6 to 5.0-5.2, suggesting that the lesser long-nosed bat can tolerate a fair degree of urbanization. Three areas of systematic uncertainty were identified of which 2 could be addressed the following summer. Due to a relatively large uncertainty in each individually measured visual limiting magnitude, Sky Quality Meter (SQM) measurements were subsequently used as a more objective source of data. In addition, the area over which the data was taken was expanded to redress spurious edge effects in making contour maps. During the summer of 2011, the second REU student took more SQM data and, with the SQM database from GLOBE at Night and the assistance of the AzGFD, performed a logistic regression analysis with respect to the bats' flight paths to determine whether the bats preferred or avoided flight through regions of particular night sky brightness levels. During the presentation, we will provide more on the analysis and conclusions of the research, as well as the extension of the program to secondary students and teachers. Should the conclusion be that the bats are preferentially staying in darker areas, a next step for students and teachers would include helping to maintain a dark corridor where the T&E lesser long nosed bats travel between roosts and foraging areas. Should this prototype project succeed, it will be used as a template for other REU and secondary school research projects on endangered animals across the U.S. affected by light pollution. Teacher professional development will play a big role in the program's future success.

Night Sky Brightness Measurement by the Public through a Mobile Phone App

NASA Astrophysics Data System (ADS)

Kamegai, Kazuhisa; Tsukada, Ken; Inoue, Hiroki

2015-08-01

The darkness of night sky is important naturally for astronomy researchers, and also for the public people. Particularly, it is meaningful for those who begin to have an interest in gazing stars. Some previous studies suggest that light pollution may affect human health and ecosystem in various ways. Furthermore, it causes a lot of waste of electric energy for lighting.In Japan, the night sky brightness had been measured by Ministry of Environment for a few decades. Recently some global efforts have been also conducted. However the number of measured position is limited because the measurement needs some apparatus and takes long time.Here we show a result of quick and easy measurements of night sky brightness by the public people through a mobile phone app. The measurements were conducted in cooperation between some members of the Tenpla project and a weather forecasting company. The app has been developed by the company and has been installed by over 6.5 million people, which allow us to get a large number of data. Our purposes are (1) making map of night sky brightness all over Japan and (2) providing an opportunity to enjoy gazing star for those who are not usually interested in astronomy.As an interactive function of the app, we put a questionnaire of four choices in which we ask users how many stars are visible in a part of the constellation of Orion. When users answer the question, we get the answer and the position where they are. Depending on the answer, we can roughly recognize the sky brightness of the position.We opened the measurements for several nights. As a result, we could get 4000 - 5000 data all over the country per night. The map of each night is a snapshot of sky brightness of the night including effect of the weather. For example we can recognize that the sky is getting darker as a function of distance from the metropolitan area of Tokyo. We will show the detail results in the presentation.

Frequency of College Students' Night-Sky Watching Behaviors

ERIC Educational Resources Information Center

Kelly, William E.; Kelly, Kathryn E.; Batey, Jason

2006-01-01

College students (N = 112) completed the Noctcaelador Inventory, a measure of psychological attachment to the night-sky, and estimated various night-sky watching related activities: frequency and duration of night-sky watching, astro-tourism, ownership of night-sky viewing equipment, and attendance of observatories or planetariums. The results…

Sky online: linking amateur and professional astronomers on the world wide web

NASA Astrophysics Data System (ADS)

Fienberg, Richard Tresch

SKY Online is the World Wide Web site of Sky Publishing Corporation, publisher of Sky & Telescope magazine. Conceived mainly as an electronic extension of the company's marketing and promotion efforts, SKY Online has also proven to be a useful tool for communication between amateur and professional astronomers.

The Sky This Week, 2016 January 19 - 26 - Naval Oceanography Portal

Science.gov Websites

are here: Home › USNO › News, Tours & Events › Sky This Week › The Sky This Week, 2016 January 19 - 26 USNO Logo USNO Navigation Tour Information USNO Scientific Colloquia Sky This Week The Sky This Week, 2016 January 19 - 26 Info The Sky This Week, 2016 January 19 - 26 See all the bright planets

The Sky This Week, 2016 April 19 - 26 - Naval Oceanography Portal

Science.gov Websites

are here: Home › USNO › News, Tours & Events › Sky This Week › The Sky This Week, 2016 April 19 - 26 USNO Logo USNO Navigation Tour Information USNO Scientific Colloquia Sky This Week The Sky This Week, 2016 April 19 - 26 Info The Sky This Week, 2016 April 19 - 26 A bright and speedy star

The Sky This Week, 2015 December 8 - 15 - Naval Oceanography Portal

Science.gov Websites

are here: Home › USNO › News, Tours & Events › Sky This Week › The Sky This Week, 2015 December 8 - 15 USNO Logo USNO Navigation Tour Information USNO Scientific Colloquia Sky This Week The Sky This Week, 2015 December 8 - 15 Info The Sky This Week, 2015 December 8 - 15 The year's best meteor

Mitigation of Volcanic Risk: The COSMO-SkyMed Contribution

NASA Astrophysics Data System (ADS)

Sacco, Patrizia; Daraio, Maria Girolamo; Battagliere, Maria Libera; Coletta, Alessandro

2015-05-01

The Italian Space Agency (ASI) promotes Earth Observation (EO) applications related to themes such as the prediction, monitoring, management and mitigation of natural and anthropogenic hazards. The approach generally followed is the development and demonstration of prototype services, using currently available data from space missions, in particular the COSMO-SkyMed (Constellation of Small Satellites for Mediterranean basin observation) mission, which represents the largest Italian investment in Space System for EO and thanks to which Italy plays a key role worldwide. Projects funded by ASI provide the convergence of various national industry expertise, research and institutional reference users. In this context a significant example is represented by the ASI Pilot Projects, recently concluded, dealing with various thematic, such as volcanoes. In this paper a special focus will be addressed to the volcanic risk management and the contribution provided in this field by COSMO-SkyMed satellite constellation during the last years. A comprehensive overview of the various national and international projects using COSMO-SkyMed data for the volcanic risk mitigation will be given, highlighting the Italian contribution provided worldwide in this operational framework.

An efficient method for removing point sources from full-sky radio interferometric maps

NASA Astrophysics Data System (ADS)

Berger, Philippe; Oppermann, Niels; Pen, Ue-Li; Shaw, J. Richard

2017-12-01

A new generation of wide-field radio interferometers designed for 21-cm surveys is being built as drift scan instruments allowing them to observe large fractions of the sky. With large numbers of antennas and frequency channels, the enormous instantaneous data rates of these telescopes require novel, efficient, data management and analysis techniques. The m-mode formalism exploits the periodicity of such data with the sidereal day, combined with the assumption of statistical isotropy of the sky, to achieve large computational savings and render optimal analysis methods computationally tractable. We present an extension to that work that allows us to adopt a more realistic sky model and treat objects such as bright point sources. We develop a linear procedure for deconvolving maps, using a Wiener filter reconstruction technique, which simultaneously allows filtering of these unwanted components. We construct an algorithm, based on the Sherman-Morrison-Woodbury formula, to efficiently invert the data covariance matrix, as required for any optimal signal-to-noise ratio weighting. The performance of our algorithm is demonstrated using simulations of a cylindrical transit telescope.

Progress in Insect-Inspired Optical Navigation Sensors

NASA Technical Reports Server (NTRS)

Thakoor, Sarita; Chahl, Javaan; Zometzer, Steve

2005-01-01

Progress has been made in continuing efforts to develop optical flight-control and navigation sensors for miniature robotic aircraft. The designs of these sensors are inspired by the designs and functions of the vision systems and brains of insects. Two types of sensors of particular interest are polarization compasses and ocellar horizon sensors. The basic principle of polarization compasses was described (but without using the term "polarization compass") in "Insect-Inspired Flight Control for Small Flying Robots" (NPO-30545), NASA Tech Briefs, Vol. 29, No. 1 (January 2005), page 61. To recapitulate: Bees use sky polarization patterns in ultraviolet (UV) light, caused by Rayleigh scattering of sunlight by atmospheric gas molecules, as direction references relative to the apparent position of the Sun. A robotic direction-finding technique based on this concept would be more robust in comparison with a technique based on the direction to the visible Sun because the UV polarization pattern is distributed across the entire sky and, hence, is redundant and can be extrapolated from a small region of clear sky in an elsewhere cloudy sky that hides the Sun.

Centre d'Observacio de l'Univers: first year of activities

NASA Astrophysics Data System (ADS)

Ribas, S. J.

2011-11-01

The Centre d'Observacio de l'Univers is one of the parts of the Parc Astronomic Montsec (PAM). PAM is an initiative of the Catalan government, through the Consorci del Montsec (Montsec Consortium), to take advantage of the capabilities and potential of the Montsec region to develop scientific research, training, and outreach activities, particularly in the field of astronomy. The choice of the Montsec mountains to install the PAM was motivated by the magnificent conditions for observing the sky at night; the sky above Montsec is the best (natural sky free of light pollution) in Catalonia for astronomical observations. The PAM has two main parts: the Observatori Astronomic del Montsec (OAdM) and the Centre d'Observacio del'Univers (COU). The OAdM is a professional observatory with an 80 cm catadioptric telescope (Joan Oro Telescope). The COU is a large multipurpose center which is intended to become an educational benchmark for teaching and communicate astronomy and other sciences in Catalonia. Since the opening more than 50000 visitors went to this center to enjoy science with Montsec dark skies and an special natural environment.

After SDSS-IV: Pioneering Panoptic Spectroscopy

NASA Astrophysics Data System (ADS)

Kollmeier, Juna; AS4 Collaboration

2018-01-01

I will describe the current plans for a next generation sky survey that will begin After SDSS-IV --- AS4. AS4 will be an unprecedented all-sky spectroscopic survey of over six million objects. It is designed to decode the history of the Milky Way galaxy, trace the emergence of the chemical elements, reveal the inner workings of stars, the growth of black holes, and investigate the origin of planets. It will provide the most comprehensive all-sky spectroscopy to multiply the science from the Gaia, TESS and eROSITA missions. AS4 will also create a contiguous spectroscopic map of the interstellar gas in the Milky Way and nearby galaxies that is 1,000 times larger than the state of the art, uncovering the self-regulation mechanisms of Galactic ecosystems. It will pioneer systematic, spectroscopic monitoring across the whole sky, revealing changes on timescales from 20 minutes to 20 years. The project is now developing new hardware to build on the SDSS-IV infrastructure, designing the detailed survey strategy, and actively seeking to complete its consortium of institutional and individual members.

Through thick and thin: quantitative classification of photometric observing conditions on Paranal

NASA Astrophysics Data System (ADS)

Kerber, Florian; Querel, Richard R.; Neureiter, Bianca; Hanuschik, Reinhard

2016-07-01

A Low Humidity and Temperature Profiling (LHATPRO) microwave radiometer is used to monitor sky conditions over ESO's Paranal observatory. It provides measurements of precipitable water vapour (PWV) at 183 GHz, which are being used in Service Mode for scheduling observations that can take advantage of favourable conditions for infrared (IR) observations. The instrument also contains an IR camera measuring sky brightness temperature at 10.5 μm. It is capable of detecting cold and thin, even sub-visual, cirrus clouds. We present a diagnostic diagram that, based on a sophisticated time series analysis of these IR sky brightness data, allows for the automatic and quantitative classification of photometric observing conditions over Paranal. The method is highly sensitive to the presence of even very thin clouds but robust against other causes of sky brightness variations. The diagram has been validated across the complete range of conditions that occur over Paranal and we find that the automated process provides correct classification at the 95% level. We plan to develop our method into an operational tool for routine use in support of ESO Science Operations.

Custom Sky-Image Mosaics from NASA's Information Power Grid

NASA Technical Reports Server (NTRS)

Jacob, Joseph; Collier, James; Craymer, Loring; Curkendall, David

2005-01-01

yourSkyG is the second generation of the software described in yourSky: Custom Sky-Image Mosaics via the Internet (NPO-30556), NASA Tech Briefs, Vol. 27, No. 6 (June 2003), page 45. Like its predecessor, yourSkyG supplies custom astronomical image mosaics of sky regions specified by requesters using client computers connected to the Internet. Whereas yourSky constructs mosaics on a local multiprocessor system, yourSkyG performs the computations on NASA s Information Power Grid (IPG), which is capable of performing much larger mosaicking tasks. (The IPG is high-performance computation and data grid that integrates geographically distributed 18 NASA Tech Briefs, September 2005 computers, databases, and instruments.) A user of yourSkyG can specify parameters describing a mosaic to be constructed. yourSkyG then constructs the mosaic on the IPG and makes it available for downloading by the user. The complexities of determining which input images are required to construct a mosaic, retrieving the required input images from remote sky-survey archives, uploading the images to the computers on the IPG, performing the computations remotely on the Grid, and downloading the resulting mosaic from the Grid are all transparent to the user

Solar heating and cooling.

PubMed

Duffie, J A; Beckman, W A

1976-01-16

We have adequate theory and engineering capability to design, install, and use equipment for solar space and water heating. Energy can be delivered at costs that are competitive now with such high-cost energy sources as much fuel-generated, electrical resistance heating. The technology of heating is being improved through collector developments, improved materials, and studies of new ways to carry out the heating processes. Solar cooling is still in the experimental stage. Relatively few experiments have yielded information on solar operation of absorption coolers, on use of night sky radiation in locations with clear skies, on the combination of a solar-operated Rankine engine and a compression cooler, and on open cycle, humidification-dehumidification systems. Many more possibilities for exploration exist. Solar cooling may benefit from collector developments that permit energy delivery at higher temperatures and thus solar operation of additional kinds of cycles. Improved solar cooling capability can open up new applications of solar energy, particularly for larger buildings, and can result in markets for retrofitting existing buildings. Solar energy for buildings can, in the next decade, make a significant contribution to the national energy economy and to the pocketbooks of many individual users. very large-aggregate enterprises in manufacture, sale, and installation of solar energy equipment can result, which can involve a spectrum of large and small businesses. In our view, the technology is here or will soon be at hand; thus the basic decisions as to whether the United States uses this resource will be political in nature.

Stars For Citizens With Urban Star Parks and Lighting Specialists

NASA Astrophysics Data System (ADS)

Grigore, Valentin

2015-08-01

General contextOne hundred years ago, almost nobody imagine a life without stars every night even in the urban areas. Now, to see a starry sky is a special event for urban citizens.It is possible to see the stars even inside cities? Yes, but for that we need star parks and lighting specialists as partners.Educational aspectThe citizens must be able to identify the planets, constellations and other celestial objects in their urban residence. This is part of a basic education. The number of the people living in the urban area who never see the main constellations or important stars increase every year. We must do something for our urban community.What is an urban star park?An urban public park where we can see the main constellations can be considered an urban star park. There can be organized a lot of activities as practical lessons of astronomy, star parties, etc.Classification of the urban star parksA proposal for classification of the urban star parks taking in consideration the quality of the sky and the number of the city inhabitants:Two categories:- city star parks for cities with < 100.000 inhabitants- metropolis star parks for cities with > 100.000 inhabitantsFive levels of quality:- 1* level = can see stars of at least 1 magnitude with the naked eyes- 2* level = at least 2 mag- 3* level = at least 3 mag- 4* level= at least 4 mag- 5* level = at least 5 magThe urban star urban park structure and lighting systemA possible structure of a urban star park and sky-friend lighting including non-electric illumination are descripted.The International Commission on IlluminationA description of this structure which has as members national commissions from all over the world.Dark-sky activists - lighting specialistsNational Commissions on Illumination organize courses of lighting specialist. Dark-sky activists can become lighting specialists. The author shows his experience in this aspect as a recent lighting specialist and his cooperation with the Romanian National Commission on Illumination working for a law of illumination in Romania and to implement the sky protection elements into the lighting specialist accreditation.

GLOBE at Night: Scientific Research outside of the Classroom

NASA Astrophysics Data System (ADS)

Henderson, S.; Walker, C. E.; Geary, E.; Pompea, S. M.

2005-12-01

Increased and robust understanding of our environment requires learning opportunities that take place outside of the traditional K-12 classroom and beyond the confines of the school day. GLOBE at Night is a new event within The GLOBE Program that provides a mechanism for a nontraditional learning activity involving teachers, students, and their families taking observations of the night sky around the world and reporting their observations via a central data base for analysis. To support activities centered on authentic research experiences such as GLOBE at Night, The GLOBE Program has changed its approach to professional development (PD). The new focus of GLOBE PD efforts is centered on teachers being able to facilitate student research in and out of the classroom reflective of authentic scientific research experiences. It has been recognized that there is a critical need for effective teacher professional development programs that support teacher involvement in meaningful scientific research that encourages partnerships between scientists, teachers, and students. Partnerships promoting scientific research for K-12 audiences provides the foundation for The GLOBE Program, an international inquiry-based program designed to engage teachers with their students in partnership with research scientists to better understand the environment at local, regional, and global scales. GLOBE is an ongoing international science and education program that unites students, teachers, and scientists in the study of the Earth System. Students participating in GLOBE engage in hands-on activities, including the collection, analysis, and sharing of research quality scientific data with their peers around the world. Students interact with members of the science community who use the data collected from locations around the world in their research - data that would often not be available otherwise. As of September 2005, over 30,000 teachers representing over 16,000 schools worldwide have participated in GLOBE workshops resulting in over 13 million environmental measurements reported by students to the GLOBE Web site. GLOBE at Night will utilize the GLOBE infrastructure and network to promote a week of night observations (February 2006) by teachers and students. The quality of the night sky for stellar observations is impacted by several factors, including human influences. GLOBE at Night will help scientists assess how the quality of the night sky varies around the world. The data that is collected will be accessible via the GLOBE Web site by scientists studying light pollution and will be available for use by teachers and students worldwide. GLOBE at Night is a collaborative effort of the NASA-sponsored GLOBE Program and the National Optical Astronomy Observatory (NOAO).

Constraining Polarized Foregrounds for EoR Experiments. II. Polarization Leakage Simulations in the Avoidance Scheme

NASA Astrophysics Data System (ADS)

Nunhokee, C. D.; Bernardi, G.; Kohn, S. A.; Aguirre, J. E.; Thyagarajan, N.; Dillon, J. S.; Foster, G.; Grobler, T. L.; Martinot, J. Z. E.; Parsons, A. R.

2017-10-01

A critical challenge in the observation of the redshifted 21 cm line is its separation from bright Galactic and extragalactic foregrounds. In particular, the instrumental leakage of polarized foregrounds, which undergo significant Faraday rotation as they propagate through the interstellar medium, may harmfully contaminate the 21 cm power spectrum. We develop a formalism to describe the leakage due to instrumental widefield effects in visibility-based power spectra measured with redundant arrays, extending the delay-spectrum approach presented in Parsons et al. We construct polarized sky models and propagate them through the instrument model to simulate realistic full-sky observations with the Precision Array to Probe the Epoch of Reionization. We find that the leakage due to a population of polarized point sources is expected to be higher than diffuse Galactic polarization at any k mode for a 30 m reference baseline. For the same reference baseline, a foreground-free window at k > 0.3 h Mpc-1 can be defined in terms of leakage from diffuse Galactic polarization even under the most pessimistic assumptions. If measurements of polarized foreground power spectra or a model of polarized foregrounds are given, our method is able to predict the polarization leakage in actual 21 cm observations, potentially enabling its statistical subtraction from the measured 21 cm power spectrum.

The Sky This Week, 2016 March 15 - 23 - Naval Oceanography Portal

Science.gov Websites

are here: Home › USNO › News, Tours & Events › Sky This Week › The Sky This Week, 2016 March 15 - 23 USNO Logo USNO Navigation Tour Information USNO Scientific Colloquia Sky This Week The Sky This Week, 2016 March 15 - 23 Info The Sky This Week, 2016 March 15 - 23 The equinox and the calendar

The Sky This Week, 2016 January 5 - 12 - Naval Oceanography Portal

Science.gov Websites

are here: Home › USNO › News, Tours & Events › Sky This Week › The Sky This Week, 2016 January 5 - 12 USNO Logo USNO Navigation Tour Information USNO Scientific Colloquia Sky This Week The Sky This Week, 2016 January 5 - 12 Info The Sky This Week, 2016 January 5 - 12 Count the stars in Orion for

Fireballs in the Sky: an Augmented Reality Citizen Science Program

NASA Astrophysics Data System (ADS)

Day, B. H.; Bland, P.; Sayers, R.

2017-12-01

Fireballs in the Sky is an innovative Australian citizen science program that connects the public with the research of the Desert Fireball Network (DFN). This research aims to understand the early workings of the solar system, and Fireballs in the Sky invites people around the world to learn about this science, contributing fireball sightings via a user-friendly augmented reality mobile app. Tens of thousands of people have downloaded the app world-wide and participated in the science of meteoritics. The Fireballs in the Sky app allows users to get involved with the Desert Fireball Network research, supplementing DFN observations and providing enhanced coverage by reporting their own meteor sightings to DFN scientists. Fireballs in the Sky reports are used to track the trajectories of meteors - from their orbit in space to where they might have landed on Earth. Led by Phil Bland at Curtin University in Australia, the Desert Fireball Network (DFN) uses automated observatories across Australia to triangulate trajectories of meteorites entering the atmosphere, determine pre-entry orbits, and pinpoint their fall positions. Each observatory is an autonomous intelligent imaging system, taking 1000×36Megapixel all-sky images throughout the night, using neural network algorithms to recognize events. They are capable of operating for 12 months in a harsh environment, and store all imagery collected. We developed a completely automated software pipeline for data reduction, and built a supercomputer database for storage, allowing us to process our entire archive. The DFN currently stands at 50 stations distributed across the Australian continent, covering an area of 2.5 million km^2. Working with DFN's partners at NASA's Solar System Exploration Research Virtual Institute, the team is expanding the network beyond Australia to locations around the world. Fireballs in the Sky allows a growing public base to learn about and participate in this exciting research.

Andromeda (M31) optical and infrared disk survey. I. Insights in wide-field near-IR surface photometry

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

Sick, Jonathan; Courteau, Stéphane; Cuillandre, Jean-Charles

We present wide-field near-infrared J and K{sub s} images of the Andromeda Galaxy (M31) taken with WIRCam at the Canada-France-Hawaii Telescope as part of the Andromeda Optical and Infrared Disk Survey. This data set allows simultaneous observations of resolved stars and near-infrared (NIR) surface brightness across M31's entire bulge and disk (within R = 22 kpc), permitting a direct test of the stellar composition of near-infrared light in a nearby galaxy. Here we develop NIR observation and reduction methods to recover a uniform surface brightness map across the 3° × 1° disk of M31 with 27 WIRCam fields. Two sky-targetmore » nodding strategies are tested, and we find that strictly minimizing sky sampling latency cannot improve background subtraction accuracy to better than 2% of the background level due to spatio-temporal variations in the NIR skyglow. We fully describe our WIRCam reduction pipeline and advocate using flats built from night-sky images over a single night, rather than dome flats that do not capture the WIRCam illumination field. Contamination from scattered light and thermal background in sky flats has a negligible effect on the surface brightness shape compared to the stochastic differences in background shape between sky and galaxy disk fields, which are ∼0.3% of the background level. The most dramatic calibration step is the introduction of scalar sky offsets to each image that optimizes surface brightness continuity. Sky offsets reduce the mean surface brightness difference between observation blocks from 1% to <0.1% of the background level, though the absolute background level remains statistically uncertain to 0.15% of the background level. We present our WIRCam reduction pipeline and performance analysis to give specific recommendations for the improvement of NIR wide-field imaging methods.« less

Predicting Clear-Sky Reflectance Over Snow/Ice in Polar Regions

NASA Technical Reports Server (NTRS)

Chen, Yan; Sun-Mack, Sunny; Arduini, Robert F.; Hong, Gang; Minnis, Patrick

2015-01-01

Satellite remote sensing of clouds requires an accurate estimate of the clear-sky radiances for a given scene to detect clouds and aerosols and to retrieve their microphysical properties. Knowing the spatial and angular variability of clear-sky albedo is essential for predicting clear-sky radiance at solar wavelengths. The Clouds and the Earth's Radiant Energy System (CERES) Project uses the nearinfrared (NIR; 1.24, 1.6 or 2.13 micrometers), visible (VIS; 0.63 micrometers) and vegetation (VEG; 0.86 micrometers) channels available on the Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) to help identify clouds and retrieve their properties in both snow-free and snow-covered conditions. Thus, it is critical to have reliable distributions of clear-sky albedo for all of these channels. In CERES Edition 4 (Ed4), the 1.24-micrometer channel is used to retrieve cloud optical depth over snow/ice-covered surfaces. Thus, it is especially critical to accurately predict the 1.24-micrometer clear-sky albedo alpha and reflectance rho for a given location and time. Snow albedo and reflectance patterns are very complex due to surface texture, particle shapes and sizes, melt water, and vegetation protrusions from the snow surface. To minimize those effects, this study focuses on the permanent snow cover of Antarctica where vegetation is absent and melt water is minimal. Clear-sky albedos are determined as a function of solar zenith angle (SZA) from observations over all scenes determined to be cloud-free to produce a normalized directional albedo model (DRM). The DRM is used to develop alpha(SZA=0 degrees) on 10 foot grid for each season. These values provide the basis for predicting r at any location and set of viewing & illumination conditions. This paper examines the accuracy of this approach for two theoretical snow surface reflectance models.

Fireballs in the Sky: An Augmented Reality Citizen Science Program

NASA Technical Reports Server (NTRS)

Day, Brian

2017-01-01

Fireballs in the Sky is an innovative Australian citizen science program that connects the public with the research of the Desert Fireball Network (DFN). This research aims to understand the early workings of the solar system, and Fireballs in the Sky invites people around the world to learn about this science, contributing fireball sightings via a user-friendly augmented reality mobile app. Tens of thousands of people have downloaded the app world-wide and participated in the science of meteoritics. The Fireballs in the Sky app allows users to get involved with the Desert Fireball Network research, supplementing DFN observations and providing enhanced coverage by reporting their own meteor sightings to DFN scientists. Fireballs in the Sky reports are used to track the trajectories of meteors - from their orbit in space to where they might have landed on Earth. Led by Phil Bland at Curtin University in Australia, the Desert Fireball Network (DFN) uses automated observatories across Australia to triangulate trajectories of meteorites entering the atmosphere, determine pre-entry orbits, and pinpoint their fall positions. Each observatory is an autonomous intelligent imaging system, taking 1000 by 36 megapixel all-sky images throughout the night, using neural network algorithms to recognize events. They are capable of operating for 12 months in a harsh environment, and store all imagery collected. We developed a completely automated software pipeline for data reduction, and built a supercomputer database for storage, allowing us to process our entire archive. The DFN currently stands at 50 stations distributed across the Australian continent, covering an area of 2.5 million square kilometers. Working with DFN's partners at NASA's Solar System Exploration Research Virtual Institute, the team is expanding the network beyond Australia to locations around the world. Fireballs in the Sky allows a growing public base to learn about and participate in this exciting research.

Anomalous celestial polarization caused by forest fire smoke: why do some insects become visually disoriented under smoky skies?

NASA Astrophysics Data System (ADS)

Hegedüs, Ramón; Åkesson, Susanne; Horváth, Gábor

2007-05-01

The effects of forest fire smoke on sky polarization and animal orientation are practically unknown. Using full-sky imaging polarimetry, we therefore measured the celestial polarization pattern under a smoky sky in Fairbanks, Alaska, during the forest fire season in August 2005. It is quantitatively documented here that the celestial polarization, a sky attribute that is necessary for orientation of many polarization-sensitive animal species, above Fairbanks on 17 August 2005 was in several aspects anomalous due to the forest fire smoke: (i) The pattern of the degree of linear polarization p of the reddish smoky sky differed considerably from that of the corresponding clear blue sky. (ii) Due to the smoke, p of skylight was drastically reduced (pmax≤14%, paverage≤8%). (iii) Depending on wavelength and time, the Arago, Babinet, and Brewster neutral points of sky polarization had anomalous positions. We suggest that the disorientation of certain insects observed by Canadian researchers under smoky skies during the forest fire season in August 2003 in British Columbia was the consequence of the anomalous sky polarization caused by the forest fire smoke.

Concept of a digital aerial platform for conducting observation flights under the open skies treaty. (Polish Title: Koncepcja cyfrowej platformy lotniczej do realizacji misji obserwacyjnych w ramach traktatu o otwartych przestworzach)

NASA Astrophysics Data System (ADS)

Walczykowski, P.; Orych, A.

2013-12-01

The Treaty on Open Skies, to which Poland is a signatory from the very beginning, was signed in 1992 in Helsinki. The main principle of the Treaty is increasing the openness of military activities conducted by the States-Parties and control over respecting disarmament agreements. Responsibilities given by the Treaty are fulfilled by conducting and receiving a given number of observation flights over the territories of the Treaty signatories. Among the 34 countries currently actively taking part in this Treaty only some own certified airplanes and observation sensors. Poland is within the group of countries who do not own their own platform and therefore fulfills Treaty requirements using the Ukrainian An-30b. Primarily, the Treaty only enabled the use of analogue sensors for the acquisition of imagery data. Together with the development of digital techniques, a rise in the need for digital imagery products had been noted. Currently digital photography is being used in almost ass fields of studies and everyday life. This has lead to very rapid developments in digital sensor technologies, employing the newest and most innovative solutions. Digital imagery products have many advantages and have now almost fully replaced traditional film sensors. Digital technologies have given rise to a new era in Open Skies. The Open Skies Consultative Commission, having conducted many series of tests, signed a new Decision to the Treaty, which allows for digital aerial sensors to be used during observation flights. The main aim of this article is to design a concept of choosing digital sensors and selecting an airplane, therefore a digital aerial platform, which could be used by Poland for Open Skies purposes. A thorough analysis of airplanes currently used by the Polish Air force was conducted in terms of their specifications and the possibility of their employment for Open Skies Treaty missions. Next, an analysis was conducted of the latest aerial digital sensors offered by leading commercial manufacturers. The sensors were analyzed in terms of the accordance of their specifications with the technical requirements of the Treaty.

It’s about time: How do sky surveys manage uncertainty about scientific needs many years into the future

NASA Astrophysics Data System (ADS)

Darch, Peter T.; Sands, Ashley E.

2016-06-01

Sky surveys, such as the Sloan Digital Sky Survey (SDSS) and the Large Synoptic Survey Telescope (LSST), generate data on an unprecedented scale. While many scientific projects span a few years from conception to completion, sky surveys are typically on the scale of decades. This paper focuses on critical challenges arising from long timescales, and how sky surveys address these challenges.We present findings from a study of LSST, comprising interviews (n=58) and observation. Conceived in the 1990s, the LSST Corporation was formed in 2003, and construction began in 2014. LSST will commence data collection operations in 2022 for ten years.One challenge arising from this long timescale is uncertainty about future needs of the astronomers who will use these data many years hence. Sources of uncertainty include scientific questions to be posed, astronomical phenomena to be studied, and tools and practices these astronomers will have at their disposal. These uncertainties are magnified by the rapid technological and scientific developments anticipated between now and the start of LSST operations.LSST is implementing a range of strategies to address these challenges. Some strategies involve delaying resolution of uncertainty, placing this resolution in the hands of future data users. Other strategies aim to reduce uncertainty by shaping astronomers’ data analysis practices so that these practices will integrate well with LSST once operations begin.One approach that exemplifies both types of strategy is the decision to make LSST data management software open source, even now as it is being developed. This policy will enable future data users to adapt this software to evolving needs. In addition, LSST intends for astronomers to start using this software well in advance of 2022, thereby embedding LSST software and data analysis approaches in the practices of astronomers.These findings strengthen arguments for making the software supporting sky surveys available as open source. Such arguments usually focus on reuse potential of software, and enhancing replicability of analyses. In this case, however, open source software also promises to mitigate the critical challenge of anticipating the needs of future data users.

SatCam: A mobile application for coordinated ground/satellite observation of clouds and validation of satellite-derived cloud mask products.

NASA Astrophysics Data System (ADS)

Gumley, L.; Parker, D.; Flynn, B.; Holz, R.; Marais, W.

2011-12-01

SatCam is an application for iOS devices that allows users to collect observations of local cloud and surface conditions in coordination with an overpass of the Terra, Aqua, or NPP satellites. SatCam allows users to acquire images of sky conditions and ground conditions at their location anywhere in the world using the built-in iPhone or iPod Touch camera at the same time that the satellite is passing overhead and viewing their location. Immediately after the sky and ground observations are acquired, the application asks the user to rate the level of cloudiness in the sky (Completely Clear, Mostly Clear, Partly Cloudy, Overcast). For the ground observation, the user selects their assessment of the surface conditions (Urban, Green Vegetation, Brown Vegetation, Desert, Snow, Water). The sky condition and surface condition selections are stored along with the date, time, and geographic location for the images, and the images are uploaded to a central server. When the MODIS (Terra and Aqua) or VIIRS (NPP) imagery acquired over the user location becomes available, a MODIS or VIIRS true color image centered at the user's location is delivered back to the SatCam application on the user's iOS device. SSEC also proposes to develop a community driven SatCam website where users can share their observations and assessments of satellite cloud products in a collaborative environment. SSEC is developing a server side data analysis system to ingest the SatCam user observations, apply quality control, analyze the sky images for cloud cover, and collocate the observations with MODIS and VIIRS satellite products (e.g., cloud mask). For each observation that is collocated with a satellite observation, the server will determine whether the user scored a "hit", meaning their sky observation and sky assessment matched the automated cloud mask obtained from the satellite observation. The hit rate will be an objective assessment of the accuracy of the user's sky observations. Users with high hit rates will be identified automatically and their observations will be used globally to evaluate the performance of the MODIS cloud mask algorithm for Terra and Aqua and the VIIRS cloud mask algorithm for NPP. The user's assessment of the ground conditions will also be used to evaluate the cloud mask accuracy in selecting the correct surface type at the user's location, which is an important element in the decision path used internally by the cloud mask algorithm. This presentation will describe the SatCam application, how it is used, and show examples of SatCam observations.

UCAC4 Nearby Star Survey: A Search for Our Stellar Neighbors

DTIC Science & Technology

2014-12-01

AAVSO) Photometric All Sky Survey (APASS) and infrared photometry from the Two Micron All-Sky Survey ( 2MASS ). With the addition of the APASS...110 million have 2MASS JHKs. We used a 3 arcsecond match radius in the development of the UCAC4 catalog for inclusion of the 2MASS and APASS...a new set of 16 photometric color–MKs relations using (a) BVgri optical photometry from APASS, (b) JHKs near-infrared photometry from 2MASS , (c

Under the Same Sky

NASA Astrophysics Data System (ADS)

Ratajczak, Milena

2016-07-01

Sharing the same sky provides the unique opportunity to use it as a tool to inspire pupils and encourage them to develop an interest in science and technology. Excitement of space can also serve as introduction to the idea of global citizenship and tolerance. A wide spectrum of educational activities dedicated to children and teenagers, especially those from less privileged backgrounds, carried out under several projects in Poland will be presented. We will also introduce the way we follow to support teachers and educators in discovering our wonderful cosmos.

CBSD Version 2 Component Models of the IR Celestial Background

DTIC Science & Technology

1990-12-07

to B1950.0) INCL Inclination of orbit (referred to B1950.0) E Eccentricity SMA Semi-major axis (AU) OBLIQ Obliquity of the ecliptic (at B1950.0) The...pre-release summary of Super Sky Flux: Plates for ecliptic latitudes >500 are scheduled to be available in Spring 1991; full-sky coverage is scheduled...individual HCON Plate sets, a three HCON co-add plate set is being developed; however, regions within ±30’ of the ecliptic plane may not be included in

The Sky This Week, 2016 January 27 - February 2 - Naval Oceanography

Science.gov Websites

Oceanography Ice You are here: Home › USNO › News, Tours & Events › Sky This Week › The Sky This Sky This Week The Sky This Week, 2016 January 27 - February 2 Info The Sky This Week, 2016 January 27 - February 2 Lest we forget. NOFS_Winter_2016_01small.jpg Dome of the Kaj Strand 1.55-meter (61-inch

Playing with stars and black holes : a way to understand the cosmology.

NASA Astrophysics Data System (ADS)

Siellez, Karelle; Durst, Clémence; Suarez, Olga

Everyday, all around the world, millions of eyes watch the sky full of stars. There are many reasons to do that: just because it's beautiful, to feel really small in this big universe, or just to dream a bit... but some people, when doing so, are wondering: "How does all this work?". Many people would like to learn more about the universe, about science. This question is universal, no matter the age or the social condition of the person. In the framework of the “science week” that is organized in France each October, our team proposed an opening space for the public at the “science village” organized at the Campus of the University of Nice (France). We proposed several activities to help people understand cosmology. To show the relation between what we can see in the sky, and what is actually happening in the universe we made the public build their own constellations in 3D thanks to our “constellation machine”. They could, thus, understand that the stars belonging to the same constellation are not side by side, but far from each other. This activity attracteded young people as well as adults. We also explained the progress in our understanding of the universe through the development of theory and observations. We used a balance to “weight” the different theories confronted to the “weight” of our knowledge of the universe represented by the observations. We could introduce, by this way, cosmology, concepts as dark matter, or dark energy. We completed the explanation with a cardboard model, where the public could touch a black hole, and experiment the deformation of the space-time. They could understand that telescopes are space-time machines and they were presented the actual work on gravitational waves and its implication on the understanding of the Big Bang. These experiments were really appreciated by the public, and we are developing them to be used with whole classes.

COBE - Cosmic Background Explorer

Science.gov Websites

with that from a precise blackbody. Data from the full four years of COBE observations continue to be stages in the COBE project. DIRBE (Diffuse Infrared Background Experiment) DIRBE has mapped the absolute sky brightness in 10 wavelength bands ranging from 1.25 microns to 240 microns. These data contain the

Experiment S030: Dim sky photography/orthicon

NASA Technical Reports Server (NTRS)

Dunkelman, L.; Mercer, R. D.; Ney, E. P.; Hemenway, C. L.

1971-01-01

During Gemini missions, the image orthicon system was used to obtain photographic data on faint and diffuse astronomical phenomena. Results show that the photographs may be used to determine the airglow geometry. Although it was sensitive, the original photographic system was unsuitable for use in the study of dim and diffuse astronomical light sources.

Looking at the sky from the depths

NASA Astrophysics Data System (ADS)

Kouchner, Antoine; Van Elewyck, Véronique

2017-11-01

Building an experiment at the bottom of the sea to detect neutrinos from outer space might seem an odd thing to do, but researchers have been perfecting the unusual pairing for half a century. Antoine Kouchner and Véronique Van Elewyck explain why and how researchers are using the ocean as a giant neutrino detector

Clear-Sky Surface Solar Radiation During South China Sea Monsoon Experiment

NASA Technical Reports Server (NTRS)

Lin, Po-Hsiung; Chou, Ming-Dah; Ji, Qiang; Tsay, Si-Chee; Einaudi, Franco (Technical Monitor)

2000-01-01

Downward solar fluxes measured at Dungsha coral island (20 deg. 42 min. N, 116 deg. 43 min. E) during the South China Sea Monsoon Experiment (May-June 1998) have been calibrated and compared with radiative transfer calculations for three clear-sky days. Model calculations use water vapor and temperature profiles from radiosound measurements and the aerosol optical thickness derived from sunphotometric radiance measurements at the surface. Results show that the difference between observed and model-calculated downward fluxes is less than 3% of the daily mean. Averaged over the three clear days, the difference reduces to 1%. The downward surface solar flux averaged over the three days is 314 W per square meters from observations and 317 W per square meters from model calculations, This result is consistent with a previous study using TOGA CAORE measurements, which found good agreements between observations and model calculations. This study provides an extra piece of useful information on the modeling of radiative transfer, which fills in the puzzle of the absorption of solar radiation in the atmosphere.

NIFTE: The Near Infrared Faint-Object Telescope Experiment

NASA Technical Reports Server (NTRS)

Bock, James J.; Lange, Andrew E.; Matsumoto, T.; Eisenhardt, Peter B.; Hacking, Perry B.; Schember, Helene R.

1994-01-01

The high sensitivity of large format InSb arrays can be used to obtain deep images of the sky at 3-5 micrometers. In this spectral range cool or highly redshifted objects (e.g. brown dwarfs and protogalaxies) which are not visible at shorter wavelengths may be observed. Sensitivity at these wavelengths in ground-based observations is severly limited by the thermal flux from the telescope and from the earth's atmosphere. The Near Infrared Faint-Object Telescope Experiment (NIFTE), a 50 cm cooled rocket-borne telescope combined with large format, high performance InSb arrays, can reach a limiting flux less than 1 micro-Jy(1-sigma) over a large field-of-view in a single flight. In comparison, the Infrared Space Observatory (ISO) will require days of observation to reach a sensitivity more than one order of magnitude worse over a similar area of the sky. The deep 3-5 micrometer images obtained by the rocket-borne telescope will assist in determining the nature of faint red objects detected by ground-based telescopes at 2 micrometers, and by ISO at wavelengths longer than 5 micrometers.

APOGEE cryostat design

NASA Astrophysics Data System (ADS)

Blank, Basil; Henderson, Chuck; Wilson, John C.; Hearty, Fred R.; Skrutskie, Michael F.; O'Brien, Thomas P.; Majewski, Steven R.; Schiavon, Ricardo; Maseman, Paul; Brunner, Sophia; Burton, Adam; Walker, Eric

2010-07-01

The Apache Point Observatory Galactic Evolution Experiment (APOGEE) is a survey of all Galactic stellar populations that will employ an R=30,000 spectrograph operating in the near-infrared (1.5-1.7μm) wavelength range. The fiber-fed spectrograph is housed in a large (1.4m x 2.3m x 1.3m) stainless steel cryostat or Dewar that is LN2-cooled and will be located in a building near the 2.5m Sloan Digital Sky Survey (SDSS) telescope to which it will be coupled. The choice of shell material and configuration was an optimization among optics packaging, weight, strength, external dimensions, rigging and transportation, the available integration and testing room, and the ultimate instrument room at APO. Internals are fabricated of more traditional 6061-T6 aluminum which is well proven in cryogenic applications. An active thermal shield with MLI blanketing yields an extremely low thermal load of 45-50 watts for this ~3000 liter instrument. Cryostat design details are discussed with applicable constraints and trade decisions. APOGEE is one of four experiments that are part of Sloan Digital Sky Survey III (SDSS-III).

Photon Physics and Plasma Research, Photonics Applications and Web Engineering, Wilga, May 2012

NASA Astrophysics Data System (ADS)

Romaniuk, Ryszard S.

2012-05-01

This paper is the third part (out of five) of the research survey of WILGA Symposium work, May 2012 Edition, concerned with Photon Physics and Plasma Research. It presents a digest of chosen technical work results shown by young researchers from different technical universities from this country during the Jubilee XXXth SPIE-IEEE Wilga 2012, May Edition, symposium on Photonics and Web Engineering. Topical tracks of the symposium embraced, among others, nanomaterials and nanotechnologies for photonics, sensory and nonlinear optical fibers, object oriented design of hardware, photonic metrology, optoelectronics and photonics applications, photonics-electronics co-design, optoelectronic and electronic systems for astronomy and high energy physics experiments, JET tokamak and pi-of-the sky experiments development. The symposium is an annual summary in the development of numerable Ph.D. theses carried out in this country in the area of advanced electronic and photonic systems. It is also a great occasion for SPIE, IEEE, OSA and PSP students to meet together in a large group spanning the whole country with guests from this part of Europe. A digest of Wilga references is presented [1-270].

Seeing the LITE

NASA Astrophysics Data System (ADS)

Brecher, K.

2000-12-01

We are developing a number of eyes-on experiments, lecture demonstrations and Web based JAVA applets about light, optics, color and visual perception as part of `Project LITE - Light Inquiry Through Experiments'. These are intended for incorporation into introductory level university science courses in astronomy, physics and other disciplines. In this presentation, several of the new LITE demonstrations applicable to large astronomy and physics classes will be shown. One demonstration involves novel materials to display Rayleigh scattering (blue skies, red sunsets and interstellar reddening - NOT redshift!) - including polarization effects. Others employ incandescent bulbs, LED's and laser pointers to illustrate fluorescence, diffraction and other physical and quantum optics phenomena. Still other demonstrations utilize transparent plastic moire overlays as well as computer animated moire patterns to show a variety of astronomical and physical phenomena. We will also display some of our applets posted at the Project LITE Web site (http://www.bu.edu/smec/lite) as well as the associated kit of optical materials we have developed for use by individual students in their own homes or dormitory rooms. This work was supported in part by NSF grant # DUE-9950551.

CLASS: The Cosmology Large Angular Scale Surveyor

NASA Technical Reports Server (NTRS)

Essinger-Hileman, Thomas; Ali, Aamir; Amiri, Mandana; Appel, John W.; Araujo, Derek; Bennett, Charles L.; Boone, Fletcher; Chan, Manwei; Cho, Hsiao-Mei; Chuss, David T.;

A Multiscale pipeline for the search of string-induced CMB anisotropies

NASA Astrophysics Data System (ADS)

Vafaei Sadr, A.; Movahed, S. M. S.; Farhang, M.; Ringeval, C.; Bouchet, F. R.

2018-03-01

We propose a multiscale edge-detection algorithm to search for the Gott-Kaiser-Stebbins imprints of a cosmic string (CS) network on the cosmic microwave background (CMB) anisotropies. Curvelet decomposition and extended Canny algorithm are used to enhance the string detectability. Various statistical tools are then applied to quantify the deviation of CMB maps having a CS contribution with respect to pure Gaussian anisotropies of inflationary origin. These statistical measures include the one-point probability density function, the weighted two-point correlation function (TPCF) of the anisotropies, the unweighted TPCF of the peaks and of the up-crossing map, as well as their cross-correlation. We use this algorithm on a hundred of simulated Nambu-Goto CMB flat sky maps, covering approximately 10 per cent of the sky, and for different string tensions Gμ. On noiseless sky maps with an angular resolution of 0.9 arcmin, we show that our pipeline detects CSs with Gμ as low as Gμ ≳ 4.3 × 10-10. At the same resolution, but with a noise level typical to a CMB-S4 phase II experiment, the detection threshold would be to Gμ ≳ 1.2 × 10-7.

First on-sky demonstration of the piezoelectric adaptive secondary mirror.

PubMed

Guo, Youming; Zhang, Ang; Fan, Xinlong; Rao, Changhui; Wei, Ling; Xian, Hao; Wei, Kai; Zhang, Xiaojun; Guan, Chunlin; Li, Min; Zhou, Luchun; Jin, Kai; Zhang, Junbo; Deng, Jijiang; Zhou, Longfeng; Chen, Hao; Zhang, Xuejun; Zhang, Yudong

2016-12-15

We propose using a piezoelectric adaptive secondary mirror (PASM) in the medium-sized adaptive telescopes with a 2-4 m aperture for structure and control simplification by utilizing the piezoelectric actuators in contrast with the voice-coil adaptive secondary mirror. A closed-loop experimental setup was built for on-sky demonstration of the 73-element PASM developed by our laboratory. In this Letter, the PASM and the closed-loop adaptive optics system are introduced. High-resolution stellar images were obtained by using the PASM to correct high-order wavefront errors in May 2016. To the best of our knowledge, this is the first successful on-sky demonstration of the PASM. The results show that with the PASM as the deformable mirror, the angular resolution of the 1.8 m telescope can be effectively improved.

Aquarius Whole Range Calibration: Celestial Sky, Ocean, and Land Targets

NASA Technical Reports Server (NTRS)

Dinnat, Emmanuel P.; Le Vine, David M.; Bindlish, Rajat; Piepmeier, Jeffrey R.; Brown, Shannon T.

2014-01-01

Aquarius is a spaceborne instrument that uses L-band radiometers to monitor sea surface salinity globally. Other applications of its data over land and the cryosphere are being developed. Combining its measurements with existing and upcoming L-band sensors will allow for long term studies. For that purpose, the radiometers calibration is critical. Aquarius measurements are currently calibrated over the oceans. They have been found too cold at the low end (celestial sky) of the brightness temperature scale, and too warm at the warm end (land and ice). We assess the impact of the antenna pattern model on the biases and propose a correction. We re-calibrate Aquarius measurements using the corrected antenna pattern and measurements over the Sky and oceans. The performances of the new calibration are evaluated using measurements over well instrument land sites.

Citizen Sky, An Update on the AAVSO's New Citizen Science Project

NASA Astrophysics Data System (ADS)

Turner, Rebecca; Price, A.; Henden, A.; Stencel, R.; Kloppenborg, B.

2011-01-01

Citizen Sky is a multi-year, NSF-funded, citizen science project focusing on the bright variable star, epsilon Aurigae. Citizen Sky goes beyond simple observing to include a major data analysis component. The goal is to introduce the participant to the full scientific process from background research to paper writing for a peer-reviewed journal. The first year of the project, 2009-10, was dedicated to developing project infrastructure, educating participants about epsilon Aurigae, and training these participants to observe the star and report their data. Looking forward, years two and three of the project will focus on assembling teams of participants to work on their own analysis and research. Results will be published in a special issue of the peer-reviewed Journal of the AAVSO. This project has been made possible by the National Science Foundation.

Development of a Carbon Sequestration Visualization Tool using Google Earth Pro

NASA Astrophysics Data System (ADS)

Keating, G. N.; Greene, M. K.

2008-12-01

The Big Sky Carbon Sequestration Partnership seeks to prepare organizations throughout the western United States for a possible carbon-constrained economy. Through the development of CO2 capture and subsurface sequestration technology, the Partnership is working to enable the region to cleanly utilize its abundant fossil energy resources. The intent of the Los Alamos National Laboratory Big Sky Visualization tool is to allow geochemists, geologists, geophysicists, project managers, and other project members to view, identify, and query the data collected from CO2 injection tests using a single data source platform, a mission to which Google Earth Pro is uniquely and ideally suited . The visualization framework enables fusion of data from disparate sources and allows investigators to fully explore spatial and temporal trends in CO2 fate and transport within a reservoir. 3-D subsurface wells are projected above ground in Google Earth as the KML anchor points for the presentation of various surface subsurface data. This solution is the most integrative and cost-effective possible for the variety of users in the Big Sky community.

A satellite AOT derived from the ground sky transmittance measurements

NASA Astrophysics Data System (ADS)

Lim, H. S.; MatJafri, M. Z.; Abdullah, K.; Tan, K. C.; Wong, C. J.; Saleh, N. Mohd.

2008-10-01

The optical properties of aerosols such as smoke from burning vary due to aging processes and these particles reach larger sizes at high concentrations. The objectives of this study are to develop and evaluate an algorithm for estimating atmospheric optical thickness from Landsat TM image. This study measured the sky transmittance at the ground using a handheld spectroradiometer in a wide wavelength spectrum to retrieve atmospheric optical thickness. The in situ measurement of atmospheric transmittance data were collected simultaneously with the acquisition of remotely sensed satellite data. The digital numbers for the three visible bands corresponding to the in situ locations were extracted and then converted into reflectance values. The reflectance measured from the satellite was subtracted by the amount given by the surface reflectance to obtain the atmospheric reflectance. These atmospheric reflectance values were used for calibration of the AOT algorithm. This study developed an empirical method to estimate the AOT values from the sky transmittance values. Finally, a AOT map was generated using the proposed algorithm and colour-coded for visual interpretation.

A Design and Development of Multi-Purpose CCD Camera System with Thermoelectric Cooling: Software

NASA Astrophysics Data System (ADS)

Oh, S. H.; Kang, Y. W.; Byun, Y. I.

2007-12-01

We present a software which we developed for the multi-purpose CCD camera. This software can be used on the all 3 types of CCD - KAF-0401E (768×512), KAF-1602E (15367times;1024), KAF-3200E (2184×1472) made in KODAK Co.. For the efficient CCD camera control, the software is operated with two independent processes of the CCD control program and the temperature/shutter operation program. This software is designed to fully automatic operation as well as manually operation under LINUX system, and is controled by LINUX user signal procedure. We plan to use this software for all sky survey system and also night sky monitoring and sky observation. As our results, the read-out time of each CCD are about 15sec, 64sec, 134sec for KAF-0401E, KAF-1602E, KAF-3200E., because these time are limited by the data transmission speed of parallel port. For larger format CCD, the data transmission is required more high speed. we are considering this control software to one using USB port for high speed data transmission.

For Spacious Skies: A Teacher's Guide. An Interdisciplinary Approach to the Sky.

ERIC Educational Resources Information Center

For Spacious Skies, Inc., Lexington, MA.

Despite the fact that the sky is the most dominant feature of our surroundings, it plays the role of an unseen background for many objects. It is the intent of this guide to bring about an awareness of the sky to young people. Topics for activities include: (1) "Sky Awareness"; (2) "Compass"; (3) "Hand Lens"; (4)…

yourSky: Custom Sky-Image Mosaics via the Internet

NASA Technical Reports Server (NTRS)

Jacob, Joseph

2003-01-01

yourSky (http://yourSky.jpl.nasa.gov) is a computer program that supplies custom astronomical image mosaics of sky regions specified by requesters using client computers connected to the Internet. [yourSky is an upgraded version of the software reported in Software for Generating Mosaics of Astronomical Images (NPO-21121), NASA Tech Briefs, Vol. 25, No. 4 (April 2001), page 16a.] A requester no longer has to engage in the tedious process of determining what subset of images is needed, nor even to know how the images are indexed in image archives. Instead, in response to a requester s specification of the size and location of the sky area, (and optionally of the desired set and type of data, resolution, coordinate system, projection, and image format), yourSky automatically retrieves the component image data from archives totaling tens of terabytes stored on computer tape and disk drives at multiple sites and assembles the component images into a mosaic image by use of a high-performance parallel code. yourSky runs on the server computer where the mosaics are assembled. Because yourSky includes a Web-interface component, no special client software is needed: ordinary Web browser software is sufficient.

Nightscape Photography Reclaims the Natural Sky

NASA Astrophysics Data System (ADS)

Tafreshi, Babak

2015-08-01

Nightscape photos and timelapse videos, where the Earth & sky are framed together with an astronomical purpose, support the dark skies activities by improving public awareness. TWAN or The World at Night program (www.twanight.org) presents the world's best collection of such landscape astrophotos and aims to introduce the night sky as a part of nature, an essential element of our living environment besides being the astronomers lab. The nightscape images also present views of our civilizations landmarks, both natural and historic sites, against the night-time backdrop of stars, planets, and celestial events. In this context TWAN is a bridge between art, science and culture.TWAN images contribute to programs such as the Dark Sky Parks by the International Dark Sky Association or Starlight reserves by assisting local efforts in better illustrating their dark skies and by producing stunning images that not only educate the local people on their night sky heritage also communicate with the governments that are responsible to support the dark sky area.Since 2009 TWAN organizes the world's largest annual photo contest on nightscape imaging, in collaboration with the Dark Skies Awareness, National Optical Astronomy Observatory, and Astronomers Without Borders. The International Earth & Sky Photo Contest promotes the photography that documents the beauty of natural skies against the problem of light pollution. In 2014 the entries received from about 50 countries and the contest result news was widely published in the most popular sources internationally.*Babak A. Tafreshi is a photographer and science communicator. He is the creator of The World At Night program, and a contributing photographer to the National Geographic, Sky&Telescope magazine, and the European Southern Observatory. http://twanight.org/tafreshi

Exploring Data Sharing Between Geographically Distributed Mobile and Fixed Nodes Supporting Extended Maritime Interdiction Operations (EMIO)

DTIC Science & Technology

2008-06-01

Diablo and LLNL o ITT Mesh, OPAREA TWO: between BP RHIB and BV, and between Sea Fox (USV) and BV o Sky Pilot, OPAREA THREE: between Tachyon ...between Sea Fox (USV) and BV o Sky Pilot, OPAREA THREE: between Tachyon Satellite and Sky Pilot Relay and between Sky Pilot Relay and BV o Wave Relay...between Tachyon Satellite and Sky Pilot Relay and between Sky Pilot Relay and BV o Wave Relay, OPAREA THREE: between BV and Balloon and between

NIXNOX project: Sites in Spain where citizens can enjoy dark starry skies

NASA Astrophysics Data System (ADS)

Zamorano, J.; de Miguel, A. Sánchez; Alfaro, E.; Martínez-Delgado, D.; Ocaña, F.; Castaño, J. Gómez; Nievas, M.

2015-03-01

The NIXNOX project, sponsored by the Spanish Astronomical Society, is a Pro-Am collaboration with the aim of finding sites with dark skies. All sky data of the night sky brightness is being obtained by amateur astronomers with Sky Quality Meter (SQM) photometers. We are not looking for remote locations because the places should be easily accessible by people with children. Our goal is to motivate citizens to observe the night sky. NIXNOX will provide information to answer the question: where can I go to observe the stars with my family?

A future wide field-of-view TeV gamma-ray observatory in the Southern Hemisphere

NASA Astrophysics Data System (ADS)

Mostafa, Miguel; HAWC Collaboration

2017-01-01

High-energy gamma-ray observations are an essential probe of cosmic-ray acceleration. Detection of the highest energies and the shortest timescales of variability are key motivations when designing the next generation of gamma-ray experiments. The Milagro experiment was the first-generation of gamma-ray detectors based on the water-Cherenkov technique, and demonstrated that it is possible to continuously monitor a large fraction of the TeV sky. The second-generation water-Cherenkov experiment, the High Altitude Water Cherenkov observatory, consists of an array of 300 water-Cherenkov detectors covering an area of 22,000 m2 at 4,100 m a.s.l. The larger effective area, the higher altitude, and the optical isolation of the detectors led to a 15-fold increase in sensitivity relative to Milagro. Instruments with a wide field of view and large duty cycle are capable of surveying the TeV sky, mapping the diffuse emission, detecting emission from extended regions, and observing transient events such as gamma ray bursts. They also have the potential for discovering electromagnetic counterparts to gravitational waves and astrophysical neutrinos. I will present the preliminary design of a third-generation water-Cherenkov observatory located at very high altitude in South America.

GRO/EGRET data analysis software: An integrated system of custom and commercial software using standard interfaces

NASA Technical Reports Server (NTRS)

Laubenthal, N. A.; Bertsch, D.; Lal, N.; Etienne, A.; Mcdonald, L.; Mattox, J.; Sreekumar, P.; Nolan, P.; Fierro, J.

1992-01-01

The Energetic Gamma Ray Telescope Experiment (EGRET) on the Compton Gamma Ray Observatory has been in orbit for more than a year and is being used to map the full sky for gamma rays in a wide energy range from 30 to 20,000 MeV. Already these measurements have resulted in a wide range of exciting new information on quasars, pulsars, galactic sources, and diffuse gamma ray emission. The central part of the analysis is done with sky maps that typically cover an 80 x 80 degree section of the sky for an exposure time of several days. Specific software developed for this program generates the counts, exposure, and intensity maps. The analysis is done on a network of UNIX based workstations and takes full advantage of a custom-built user interface called X-dialog. The maps that are generated are stored in the FITS format for a collection of energies. These, along with similar diffuse emission background maps generated from a model calculation, serve as input to a maximum likelihood program that produces maps of likelihood with optional contours that are used to evaluate regions for sources. Likelihood also evaluates the background corrected intensity at each location for each energy interval from which spectra can be generated. Being in a standard FITS format permits all of the maps to be easily accessed by the full complement of tools available in several commercial astronomical analysis systems. In the EGRET case, IDL is used to produce graphics plots in two and three dimensions and to quickly implement any special evaluation that might be desired. Other custom-built software, such as the spectral and pulsar analyses, take advantage of the XView toolkit for display and Postscript output for the color hard copy. This poster paper outlines the data flow and provides examples of the user interfaces and output products. It stresses the advantages that are derived from the integration of the specific instrument-unique software and powerful commercial tools for graphics and statistical evaluation. This approach has several proven advantages including flexibility, a minimum of development effort, ease of use, and portability.

Nocturnal cooling in a very shallow cold air pool

NASA Astrophysics Data System (ADS)

Rakovec, Jože; Skok, Gregor; Žabkar, Rahela; Žagar, Nedjeljka

2015-04-01

Cold air pools (CAPs) may develop during nights in very shallow depressions. The depth of the stagnant air within a CAP influences the process of the cooling of nocturnal air and the resulting minimum temperature. A seven-month long field experiment was performed during winter 2013/2014 in an orchard near Kr\\vsko, Slovenia, located inside a very shallow basin only a few meters deep and approximately 500 m wide. Two locations at different elevations inside the basin were selected for measurement. The results showed that the nights (in terms of cooling) can be classified into three main categories; nights with overcast skies and weak cooling, windy nights with clear sky and strong cooling but with no difference in temperatures between locations inside the basin, and calm nights with even stronger cooling and significant temperature differences between locations inside the basin. On calm nights with clear skies, the difference at two measuring sites inside the basin can be up to 5 °C but the presence of even weak winds can cause sufficient turbulent mixing to negate any difference in temperature. To better understand the cooling process on calm, clear nights, we developed a simple 1-D thermodynamic conceptual model focusing on a very shallow CAP. The model has 5-layers (including two air layers representing air inside the CAP), and an analytical solution was obtained for the equilibrium temperatures. Sensitivity analysis of the model was performed. As expected, a larger soil heat conductivity or higher temperature in the ground increases the morning minimum temperatures. An increase in temperature of the atmosphere also increases the simulated minimum temperatures, while the temperature difference between the higher and lower locations remains almost the same. An increase in atmosphere humidity also increases the modelled equilibrium temperatures, while an increase of the humidity of the air inside the CAP results in lower equilibrium temperatures. The humidity of the air within the CAP and that of the free atmosphere strongly influence the differences in equilibrium temperatures at higher and lower locations. The more humid the air, the stronger the cooling at the lower location compared to the higher location.

New optical package and algorithms for accurate estimation and interactive recording of the cloud cover information over land and sea

NASA Astrophysics Data System (ADS)

Krinitskiy, Mikhail; Sinitsyn, Alexey; Gulev, Sergey

2014-05-01

Cloud fraction is a critical parameter for the accurate estimation of short-wave and long-wave radiation - one of the most important surface fluxes over sea and land. Massive estimates of the total cloud cover as well as cloud amount for different layers of clouds are available from visual observations, satellite measurements and reanalyses. However, these data are subject of different uncertainties and need continuous validation against highly accurate in-situ measurements. Sky imaging with high resolution fish eye camera provides an excellent opportunity for collecting cloud cover data supplemented with additional characteristics hardly available from routine visual observations (e.g. structure of cloud cover under broken cloud conditions, parameters of distribution of cloud dimensions). We present operational automatic observational package which is based on fish eye camera taking sky images with high resolution (up to 1Hz) in time and a spatial resolution of 968x648px. This spatial resolution has been justified as an optimal by several sensitivity experiments. For the use of the package at research vessel when the horizontal positioning becomes critical, a special extension of the hardware and software to the package has been developed. These modules provide the explicit detection of the optimal moment for shooting. For the post processing of sky images we developed a software realizing the algorithm of the filtering of sunburn effect in case of small and moderate could cover and broken cloud conditions. The same algorithm accurately quantifies the cloud fraction by analyzing color mixture for each point and introducing the so-called "grayness rate index" for every pixel. The accuracy of the algorithm has been tested using the data collected during several campaigns in 2005-2011 in the North Atlantic Ocean. The collection of images included more than 3000 images for different cloud conditions supplied with observations of standard parameters. The system is fully autonomous and has a block for digital data collection at the hard disk. The system has been tested for a wide range of open ocean cloud conditions and we will demonstrate some pilot results of data processing and physical interpretation of fractional cloud cover estimation.

``Dark Skies are a Universal Resource'' Programs Planned for the International Year of Astronomy

NASA Astrophysics Data System (ADS)

Walker, C. E.; Berglund, K.; Bueter, C.; Crelin, B.; Duriscoe, D.; Moore, C.; Gauthier, A.; Gay, P. L.; Foster, T.; Heatherly, S. A.; Maddalena, R.; Mann, T.; Patten, K.; Pompea, S. M.; Sparks, R.; Schaaf, F.; Simmons, M.; Smith, C.; Smith, M.; Tafreshi, B.

2008-11-01

In an effort to help more people appreciate the ongoing loss of a dark night sky for much of the world's population and to raise public knowledge about diverse impacts of excess artificial lighting on local environments, the International Year of Astronomy's Dark Skies Working Group has established six ``Dark Skies'' programs and six ``Dark Skies'' resources. The Dark Skies programs include GLOBE at Night (with Earth Hour), Astronomy Nights in the [National] Parks, Dark Skies Discovery Sites, Quiet Skies, Good Neighbor Lighting, and a digital photography contest. Resources include the light education toolkit, the ``Let There Be Night'' DVD and planetarium program, the 6-minute video, online interactions like Second Life, podcasts, and traveling exhibits. The programs and resources are summarized here, as they were in a poster for the June 2008 ASP/AAS conference. For more information on these programs and resources, visit http://astronomy2009.us/darkskies/.

Observations of the Earth's Radiation Budget in relation to atmospheric hydrology. 4: Atmospheric column radiative cooling over the world's oceans

NASA Technical Reports Server (NTRS)

Stephens, Graeme L.; Slingo, Anthony; Webb, Mark J.; Minnett, Peter J.; Daum, Peter H.; Kleinman, Lawrence; Wittmeyer, Ian; Randall, David A.

1994-01-01

This paper introduces a simple method for deriving climatological values of the longwave flux emitted from the clear sky atmosphere to the ice-free ocean surface. It is shown using both theory and data from simulations how the ratio of the surface to top-of-atmosphere (TOA) flux is a simple function of water vapor (W) and a validation of the simple relationship is presented based on a limited set of surface flux measurements. The rms difference between the retrieved surface fluxes and the simulated surface fluxes is approximately 6 W/sq m. The clear sky column cooling rate of the atmosphere is derived from the Earth Radiation Budget Experiment (ERBE) values of the clear sky TOA flux and the surface flux retrieved using Special Scanning Microwave Imager (SSM/I) measurements of w together with ERBE clear sky fluxes. The relationship between this column cooling rate, w, and the sea surface temperature (SST) is explored and it is shown how the cooling rate systematically increases as both w and SST increase. The uncertainty implied in these estmates of cooling are approximately +/- 0.2 K/d. The effects of clouds on this longwave cooling are also explored by placing bounds on the possible impact of clouds on the column cooling rate based on certain assumptions about the effect of clouds on the longwave flux to the surface. It is shown how the longwave effects of clouds in a moist atmosphere where the column water vapor exceeds approximately 30 kg/sq m may be estimated from presently available satellite data with an uncertainty estimated to be approximately 0.2 K/d. Based on an approach described in this paper, we show how clouds in these relatively moist regions decrease the column cooling by almost 50% of the clear sky values and the existence of significant longitudinal gradients in column radiative heating across the equatorial and subtropical Pacific Ocean.

Sky Fest: A Model of Successful Scientist Participation in E/PO

NASA Astrophysics Data System (ADS)

Dalton, H.; Shipp, S. S.; Shaner, A. J.; LaConte, K.; Shupla, C. B.

2014-12-01

Participation in outreach events is an easy way for scientists to get involved with E/PO and reach many people with minimal time commitment. At the Lunar and Planetary Institute (LPI) in Houston, Texas, the E/PO team holds Sky Fest outreach events several times a year. These events each have a science content theme and include several activities for children and their parents, night sky viewing through telescopes, and scientist presentations. LPI scientists have the opportunity to participate in Sky Fest events either by helping lead an activity or by giving the scientist presentation (a short lecture and/or demonstration). Scientists are involved in at least one preparation meeting before the event. This allows them to ask questions, understand what activity they will be leading, and learn the key points that they should be sharing with the public, as well as techniques for effectively teaching members of the public about the event topic. During the event, each activity is run by one E/PO specialist and one scientist, enabling the scientist to learn about effective E/PO practices from the E/PO specialist and the E/PO specialist to get more science information about the event topic. E/PO specialists working together with scientists at stations provides a more complete, richer experience for event participants. Surveys of event participants have shown that interacting one-on-one with scientists is often one of their favorite parts of the events. Interviews with scientists indicated that they enjoyed Sky Fest because there was very little time involved on their parts outside of the actual event; the activities were created and/or chosen by the E/PO professionals, and setup for the events was completed before they arrived. They also enjoyed presenting their topic to people without a background in science, and who would not have otherwise sought out the information that was presented.

The super greenhouse effect in a warming world: the role of dynamics and thermodynamics

NASA Astrophysics Data System (ADS)

Kashinath, Karthik; O'Brien, Travis; Collins, William

2016-04-01

Over warm tropical oceans the increase in greenhouse trapping with increasing SST can be faster than that of the surface emission, resulting in a decrease in clear sky outgoing longwave radiation at the top of the atmosphere (OLR) when SST increases, also known as the super greenhouse effect (SGE). If the SGE is directly linked to SST changes, there are profound implications for positive climate feedbacks in the tropics. We show that CMIP5 models perform well in simulating the observed clear-sky greenhouse effect in the present day. Using global warming experiments we show that the onset and shutdown SST of the SGE, as well as the magnitude of the SGE, increase as the convective threshold SST increases. To account for an increasing convective threshold SST we use an invariant coordinate for convection proposed in a recent study [Williams et al., GRL (2009)]. However, even after accounting for the increase in tropical SST (by normalizing the SGE by surface emission) and accounting for the increase in the threshold temperature for convection (by using the invariant coordinate) we find that the models predict a distinct increase in the clear-sky greenhouse effect in a warmed world. This suggests that thermodynamics (i.e. SST) plays a crucial role in regulating the increasing clear sky greenhouse effect in a warming world. We use theoretical arguments to estimate this increase in SGE and derive its dependence on SST. Finally, as shown in previous studies, we confirm that the increase in the clear-sky greenhouse effect is primarily due to upper tropospheric moistening. Although the absolute increase in upper tropospheric water vapor is small compared to that of the lower troposphere, since the absorptivity scales with fractional changes in water vapor, the contribution of the upper troposphere is more significant, as shown by Chung et al., PNAS (2014).

Improving the sensitivity of gamma-ray telescopes to dark matter annihilation in dwarf spheroidal galaxies

DOE PAGES

Carlson, Eric; Hooper, Dan; Linden, Tim

2015-03-01

The Fermi-LAT Collaboration has studied the gamma-ray emission from a stacked population of dwarf spheroidal galaxies and used this information to set constraints on the dark matter annihilation cross section. Interestingly, their analysis uncovered an excess with a test statistic (TS) of 8.7. If interpreted naively, this constitutes a 2.95σ local excess (p-value=0.003), relative to the expectations of their background model. In order to further test this interpretation, the Fermi-LAT team studied a large number of blank sky locations and found TS>8.7 excesses to be more common than predicted by their background model, decreasing the significance of their dwarf excessmore » to 2.2σ(p-value=0.027). We argue that these TS>8.7 blank sky locations are largely the result of unresolved blazars, radio galaxies, and star-forming galaxies, and show that multiwavelength information can be used to reduce the degree to which such sources contaminate the otherwise blank sky. In particular, we show that masking regions of the sky that lie within 1° of sources contained in the BZCAT or CRATES catalogs reduce the fraction of blank sky locations with TS>8.7 by more than a factor of 2. Taking such multiwavelength information into account can enable experiments such as Fermi to better characterize their backgrounds and increase their sensitivity to dark matter in dwarf galaxies, the most important of which remain largely uncontaminated by unresolved point sources. We also note that for the range of dark matter masses and annihilation cross sections currently being tested by studies of dwarf spheroidal galaxies, simulations predict that Fermi should be able to detect a significant number of dark matter subhalos. These subhalos constitute a population of subthreshold gamma-ray point sources and represent an irreducible background for searches for dark matter annihilation in dwarf galaxies.« less

A Method for Assessing the Quality of Model-Based Estimates of Ground Temperature and Atmospheric Moisture Using Satellite Data

NASA Technical Reports Server (NTRS)

Wu, Man Li C.; Schubert, Siegfried; Lin, Ching I.; Stajner, Ivanka; Einaudi, Franco (Technical Monitor)

2000-01-01

A method is developed for validating model-based estimates of atmospheric moisture and ground temperature using satellite data. The approach relates errors in estimates of clear-sky longwave fluxes at the top of the Earth-atmosphere system to errors in geophysical parameters. The fluxes include clear-sky outgoing longwave radiation (CLR) and radiative flux in the window region between 8 and 12 microns (RadWn). The approach capitalizes on the availability of satellite estimates of CLR and RadWn and other auxiliary satellite data, and multiple global four-dimensional data assimilation (4-DDA) products. The basic methodology employs off-line forward radiative transfer calculations to generate synthetic clear-sky longwave fluxes from two different 4-DDA data sets. Simple linear regression is used to relate the clear-sky longwave flux discrepancies to discrepancies in ground temperature ((delta)T(sub g)) and broad-layer integrated atmospheric precipitable water ((delta)pw). The slopes of the regression lines define sensitivity parameters which can be exploited to help interpret mismatches between satellite observations and model-based estimates of clear-sky longwave fluxes. For illustration we analyze the discrepancies in the clear-sky longwave fluxes between an early implementation of the Goddard Earth Observing System Data Assimilation System (GEOS2) and a recent operational version of the European Centre for Medium-Range Weather Forecasts data assimilation system. The analysis of the synthetic clear-sky flux data shows that simple linear regression employing (delta)T(sub g)) and broad layer (delta)pw provides a good approximation to the full radiative transfer calculations, typically explaining more thin 90% of the 6 hourly variance in the flux differences. These simple regression relations can be inverted to "retrieve" the errors in the geophysical parameters, Uncertainties (normalized by standard deviation) in the monthly mean retrieved parameters range from 7% for (delta)T(sub g) to approx. 20% for the lower tropospheric moisture between 500 hPa and surface. The regression relationships developed from the synthetic flux data, together with CLR and RadWn observed with the Clouds and Earth Radiant Energy System instrument, ire used to assess the quality of the GEOS2 T(sub g) and pw. Results showed that the GEOS2 T(sub g) is too cold over land, and pw in upper layers is too high over the tropical oceans and too low in the lower atmosphere.

For Spacious Skies Activity Guide. An Interdisciplinary Approach to the Sky.

ERIC Educational Resources Information Center

Ward, C. Whitney; Borden, Jack

Despite the fact that the sky is the most dominant feature of our surroundings, it plays the role of an unseen background for may objects. It is the intent of this guide to bring about an awareness of the sky to young people. Topics for activities include: (1) "Sky Awareness"; (2) "Compass"; (3) "Hand Lens"; (4) "Prism"; (5) "Binoculars"; (6)…

Constraining foreground spectrum with the projection-induced polarization for the cosmological global 21-cm experiments

NASA Astrophysics Data System (ADS)

Nhan, Bang D.; Bradley, Richard F.; Burns, Professor O.

2018-01-01

Detecting the cosmological global (sky-averaged) 21-cm spectrum as a function of observed frequency will provide a powerful tool to study the thermal history of intergalactic medium (IGM) in the high-redshift Universe (~ 400 million years after the Big Bang). The biggest challenge in conventional ground-based total-power global 21-cm experiments is the removal of the Galactic and extragalactic synchrotron foreground (~ 1e4-1e5 K) to uncover the weak cosmological signal (~ 10-100 mK). The foreground is further corrupted by the frequency-dependent instrumental systematics. We have developed a new polarimetry-based observational approach that aims to measure the foreground emission by modulating it as a function of time through its circumpolar motion. Due to geometry, the projection of the anisotropic foreground sources onto the dual-polarized antenna induces a net foreground polarization, which is distinct from the much weaker intrinsic polarization of synchrotron sources. Instead of pointing the radio antenna at the zenith as in the conventional experiments, we point the antenna at the North Celestial Pole (NCP) and measure the projection-induced polarization modulated by the foreground's circumpolar diurnal periodicity. This temporal signature allows us to separate the dynamic foreground spectrum from the static cosmological background. In this presentation, we describe the design, construction, and initial results from the "Cosmic Twilight Polarimeter'' (CTP) as a proof-of-concept implementation of this technique. The instrument consists of a dual-polarized broadband antenna (60-120 MHz) with a two-stage thermally stabilized front-end electronics, tilted toward the NCP. The instrument is currently being evaluated at a site near Charlottesville, VA. Ultimately, the instrument will be relocated to an RFI-quiet site closer to the Geographic North Pole (GNP) to mitigate sky obstruction due to the horizon at a lower latitude.

Radiometric modeling and calibration of the Geostationary Imaging Fourier Transform Spectrometer (GIFTS) ground based measurement experiment

NASA Astrophysics Data System (ADS)

Tian, Jialin; Smith, William L.; Gazarik, Michael J.

2008-12-01

The ultimate remote sensing benefits of the high resolution Infrared radiance spectrometers will be realized with their geostationary satellite implementation in the form of imaging spectrometers. This will enable dynamic features of the atmosphere's thermodynamic fields and pollutant and greenhouse gas constituents to be observed for revolutionary improvements in weather forecasts and more accurate air quality and climate predictions. As an important step toward realizing this application objective, the Geostationary Imaging Fourier Transform Spectrometer (GIFTS) Engineering Demonstration Unit (EDU) was successfully developed under the NASA New Millennium Program, 2000-2006. The GIFTS-EDU instrument employs three focal plane arrays (FPAs), which gather measurements across the long-wave IR (LWIR), short/mid-wave IR (SMWIR), and visible spectral bands. The GIFTS calibration is achieved using internal blackbody calibration references at ambient (260 K) and hot (286 K) temperatures. In this paper, we introduce a refined calibration technique that utilizes Principle Component (PC) analysis to compensate for instrument distortions and artifacts, therefore, enhancing the absolute calibration accuracy. This method is applied to data collected during the GIFTS Ground Based Measurement (GBM) experiment, together with simultaneous observations by the accurately calibrated AERI (Atmospheric Emitted Radiance Interferometer), both simultaneously zenith viewing the sky through the same external scene mirror at ten-minute intervals throughout a cloudless day at Logan Utah on September 13, 2006. The accurately calibrated GIFTS radiances are produced using the first four PC scores in the GIFTS-AERI regression model. Temperature and moisture profiles retrieved from the PC-calibrated GIFTS radiances are verified against radiosonde measurements collected throughout the GIFTS sky measurement period. Using the GIFTS GBM calibration model, we compute the calibrated radiances from data collected during the moon tracking and viewing experiment events. From which, we derive the lunar surface temperature and emissivity associated with the moon viewing measurements.

Radiometric Modeling and Calibration of the Geostationary Imaging Fourier Transform Spectrometer (GIFTS)Ground Based Measurement Experiment

NASA Technical Reports Server (NTRS)

Tian, Jialin; Smith, William L.; Gazarik, Michael J.

2008-01-01

The ultimate remote sensing benefits of the high resolution Infrared radiance spectrometers will be realized with their geostationary satellite implementation in the form of imaging spectrometers. This will enable dynamic features of the atmosphere s thermodynamic fields and pollutant and greenhouse gas constituents to be observed for revolutionary improvements in weather forecasts and more accurate air quality and climate predictions. As an important step toward realizing this application objective, the Geostationary Imaging Fourier Transform Spectrometer (GIFTS) Engineering Demonstration Unit (EDU) was successfully developed under the NASA New Millennium Program, 2000-2006. The GIFTS-EDU instrument employs three focal plane arrays (FPAs), which gather measurements across the long-wave IR (LWIR), short/mid-wave IR (SMWIR), and visible spectral bands. The GIFTS calibration is achieved using internal blackbody calibration references at ambient (260 K) and hot (286 K) temperatures. In this paper, we introduce a refined calibration technique that utilizes Principle Component (PC) analysis to compensate for instrument distortions and artifacts, therefore, enhancing the absolute calibration accuracy. This method is applied to data collected during the GIFTS Ground Based Measurement (GBM) experiment, together with simultaneous observations by the accurately calibrated AERI (Atmospheric Emitted Radiance Interferometer), both simultaneously zenith viewing the sky through the same external scene mirror at ten-minute intervals throughout a cloudless day at Logan Utah on September 13, 2006. The accurately calibrated GIFTS radiances are produced using the first four PC scores in the GIFTS-AERI regression model. Temperature and moisture profiles retrieved from the PC-calibrated GIFTS radiances are verified against radiosonde measurements collected throughout the GIFTS sky measurement period. Using the GIFTS GBM calibration model, we compute the calibrated radiances from data collected during the moon tracking and viewing experiment events. From which, we derive the lunar surface temperature and emissivity associated with the moon viewing measurements.

Sky coverage modeling for the whole sky for laser guide star multiconjugate adaptive optics.

PubMed

Wang, Lianqi; Andersen, David; Ellerbroek, Brent

2012-06-01

The scientific productivity of laser guide star adaptive optics systems strongly depends on the sky coverage, which describes the probability of finding natural guide stars for the tip/tilt wavefront sensor(s) to achieve a certain performance. Knowledge of the sky coverage is also important for astronomers planning their observations. In this paper, we present an efficient method to compute the sky coverage for the laser guide star multiconjugate adaptive optics system, the Narrow Field Infrared Adaptive Optics System (NFIRAOS), being designed for the Thirty Meter Telescope project. We show that NFIRAOS can achieve more than 70% sky coverage over most of the accessible sky with the requirement of 191 nm total rms wavefront.

Radiative transfer model validations during the First ISLSCP Field Experiment

NASA Technical Reports Server (NTRS)

Frouin, Robert; Breon, Francois-Marie; Gautier, Catherine

1990-01-01

Two simple radiative transfer models, the 5S model based on Tanre et al. (1985, 1986) and the wide-band model of Morcrette (1984) are validated by comparing their outputs with results obtained during the First ISLSCP Field Experiment on concomitant radiosonde, aerosol turbidity, and radiation measurements and sky photographs. Results showed that the 5S model overestimates the short-wave irradiance by 13.2 W/sq m, whereas the Morcrette model underestimated the long-wave irradiance by 7.4 W/sq m.

The Indian ocean experiment: aerosol forcing obtained from satellite data

NASA Astrophysics Data System (ADS)

Rajeev, K.; Ramanathan, V.

The tropical Indian Ocean provides an ideal and unique natural laboratory to observe and understand the role of anthropogenic aerosols in climate forcing. Since 1996, an international team of American, European and Indian scientists have been collecting aerosol, chemical and radiation data from ships and surface stations, which culminated in a multi-platform field experiment conducted during January to March of 1999. A persistent haze layer that spread over most of the northern Indian Ocean during wintertime was discovered. The layer, a complex mix of organics, black carbon, sulfates, nitrates and other species, subjects the lower atmosphere to a strong radiative heating and a larger reduction in the solar heating of the ocean. We present here the regional distribution of aerosols and the resulting clear sky aerosol radiative forcing at top-of-atmosphere (TOA) observed over the Indian Ocean during the winter months of 1997, 1998 and 1999 based on the aerosol optical depth (AOD) estimated using NOAA14-AVHRR and the TOA radiation budget data from CERES on board TRMM. Using the ratio of surface to TOA clear sky aerosol radiative forcing observed during the same period over the Indian Ocean island of Kaashidhoo (Satheesh and Ramanathan, 2000), the clear sky aerosol radiative forcing at the surface and the atmosphere are discussed. The regional maps of AVHRR derived AOD show abnormally large aerosol concentration during the winter of 1999 which is about 1.5 to 2 times larger than the AOD during the corresponding period of 1997 and 1998. A large latitudinal gradient in AOD is observed during all the three years of observation, with maximum AOD in the northern hemisphere. The diurnal mean clear sky aerosol forcing at TOA in the northern hemisphere Indian Ocean is in the range of -4 to -16 Wm -2 and had large spatio-temporal variations while in the southern hemisphere Indian Ocean it is in the range of 0 to -6Wm -2. The importance of integrating in-situ data with satellite data to get reliable picture of the regional scale aerosol forcing is demonstrated.

Towards an Automated Classification of Transient Events in Synoptic Sky Surveys

NASA Technical Reports Server (NTRS)

Djorgovski, S. G.; Donalek, C.; Mahabal, A. A.; Moghaddam, B.; Turmon, M.; Graham, M. J.; Drake, A. J.; Sharma, N.; Chen, Y.

2011-01-01

We describe the development of a system for an automated, iterative, real-time classification of transient events discovered in synoptic sky surveys. The system under development incorporates a number of Machine Learning techniques, mostly using Bayesian approaches, due to the sparse nature, heterogeneity, and variable incompleteness of the available data. The classifications are improved iteratively as the new measurements are obtained. One novel featrue is the development of an automated follow-up recommendation engine, that suggest those measruements that would be the most advantageous in terms of resolving classification ambiguities and/or characterization of the astrophysically most interesting objects, given a set of available follow-up assets and their cost funcations. This illustrates the symbiotic relationship of astronomy and applied computer science through the emerging disciplne of AstroInformatics.

Algolcam: Low Cost Sky Scanning with Modern Technology

NASA Astrophysics Data System (ADS)

Connors, Martin; Bolton, Dempsey; Doktor, Ian

2016-01-01

Low cost DSLR cameras running under computer control offer good sensitivity, high resolution, small size, and the convenience of digital image handling. Recent developments in small single board computers have pushed the performance to cost and size ratio to unprecedented values, with the further advantage of very low power consumption. Yet a third technological development is motor control electronics which is easily integrated with the computer to make an automated mount, which in our case is custom built, but with similar mounts available commercially. Testing of such a system under a clear plastic dome at our auroral observatory was so successful that we have developed a weatherproof housing allowing use during the long, cold, and clear winter nights at northerly latitudes in Canada. The main advantage of this housing should be improved image quality as compared to operation through clear plastic. We have improved the driving software to include the ability to self-calibrate pointing through the web API of astrometry.net, and data can be reduced automatically through command line use of the Muniwin program. The mount offers slew in declination and RA, and tracking at sidereal or other rates in RA. Our previous tests with a Nikon D5100 with standard lenses in the focal length range 50-200 mm, operating at f/4 to f/5, allowed detection of 12th magnitude stars with 30 second exposure under very dark skies. At 85 mm focal length, a field of 15° by 10° is imaged with 4928 by 3264 color pixels, and we have adopted an 85 mm fixed focal length f/1.4 lens (as used by Project Panoptes), which we expect will give a limited magnitude approaching 15. With a large field of view, deep limiting magnitude, low cost, and ease of construction and use, we feel that the Algolcam offers great possibilities in monitoring and finding changes in the sky. We have already applied it to variable star light curves, and with a suitable pipeline for detection of moving or varying objects, it offers great potential for analysis and discovery. The use of low cost cutting edge technology makes Algolcam particularly interesting for enhancing the advanced undergraduate learning experience in astronomy.

Coevolution of nonlinear trends in vegetation, soils, and topography with elevation and slope aspect: A case study in the sky islands of southern Arizona

NASA Astrophysics Data System (ADS)

Pelletier, Jon D.; Barron-Gafford, Greg A.; Breshears, David D.; Brooks, Paul D.; Chorover, Jon; Durcik, Matej; Harman, Ciaran J.; Huxman, Travis E.; Lohse, Kathleen A.; Lybrand, Rebecca; Meixner, Tom; McIntosh, Jennifer C.; Papuga, Shirley A.; Rasmussen, Craig; Schaap, Marcel; Swetnam, Tyson L.; Troch, Peter A.

2013-06-01

among vegetation dynamics, pedogenesis, and topographic development affect the "critical zone"—the living filter for Earth's hydrologic, biogeochemical, and rock/sediment cycles. Assessing the importance of such feedbacks, which may be particularly pronounced in water-limited systems, remains a fundamental interdisciplinary challenge. The sky islands of southern Arizona offer an unusually well-defined natural experiment involving such feedbacks because mean annual precipitation varies by a factor of five over distances of approximately 10 km in areas of similar rock type (granite) and tectonic history. Here we compile high-resolution, spatially distributed data for Effective Energy and Mass Transfer (EEMT: the energy available to drive bedrock weathering), above-ground biomass, soil thickness, hillslope-scale topographic relief, and drainage density in two such mountain ranges (Santa Catalina: SCM; Pinaleño: PM). Strong correlations exist among vegetation-soil-topography variables, which vary nonlinearly with elevation, such that warm, dry, low-elevation portions of these ranges are characterized by relatively low above-ground biomass, thin soils, minimal soil organic matter, steep slopes, and high drainage densities; conversely, cooler, wetter, higher elevations have systematically higher biomass, thicker organic-rich soils, gentler slopes, and lower drainage densities. To test if eco-pedo-geomorphic feedbacks drive this pattern, we developed a landscape evolution model that couples pedogenesis and topographic development over geologic time scales, with rates explicitly dependent on vegetation density. The model self-organizes into states similar to those observed in SCM and PM. Our results highlight the potential importance of eco-pedo-geomorphic feedbacks, mediated by soil thickness, in water-limited systems.

The Sky This Week, 2016 March 1 - 8 - Naval Oceanography Portal

Science.gov Websites

submit many observations from different locations throughout the year. This is a great time to start are here: Home › USNO › News, Tours & Events › Sky This Week › The Sky This Week, 2016 March 1 - 8 USNO Logo USNO Navigation Tour Information USNO Scientific Colloquia Sky This Week The Sky

The sky as a topic in science education

NASA Astrophysics Data System (ADS)

Galili, Igal; Weizman, Ayelet; Cohen, Ariel

2004-07-01

The concepts of sky and visibility distance, as perceived by different learners, are investigated for the first time as a subject of a science education research. Mental models of students with regard to the subject were elicited. They were interpreted in terms of two-level hierarchy: schemes and facets-of-knowledge (defined in the paper). Our results suggest that many students do not consider sky to be a scientific (physical) concept. The majority perceives the sky as having an oblate profile. Among the parameters that determine this profile were mentioned daytime, atmosphere, geometry of the situation, and weather conditions. The students hold two major explanatory views (schemes) with regard to the sky: the sky is the atmosphere and the sky is the appearance of space. With regard to the visibility distance, the two following schemes prevail: vision weakens with the distance and natural obstacles determine vision distance. No significant correlation was found between the views regarding the sky appearance and the vision distance. Students do not relate Moon illusion to the profile of sky or visibility distance. The notions of sky and visibility distance are argued for inclusion into science curriculum, and implications of the findings to a constructivist instruction of the considered concepts and phenomena are discussed.

Novel method to avoid the open-sky condition in penetrating keratoplasty: covered cornea technique.

PubMed

Arslan, Osman S; Unal, Mustafa; Arici, Ceyhun; Cicik, Erdoğan; Mangan, Serhat; Atalay, Eray

2014-09-01

The aim of this study was to present a novel technique to avoid the open-sky condition in pediatric and adult penetrating keratoplasty (PK). Seventy-two eyes of 65 infants and children and 44 eyes of 44 adult patients were operated on using this technique. After trephining the recipient cornea up to a depth of 50% to 70%, the anterior chamber was entered at 1 point. Then, only a 2 clock hour segment of the recipient button was incised, and this segment was sutured to the recipient rim with a single tight suture. The procedure was repeated until the entire recipient button was excised and resutured. The donor corneal button was sutured to the recipient corneal rim. The sutures between the recipient button and the rim were then cut off, and the recipient button was drawn out. None of the patients operated on with this technique developed complications related to the open-sky condition. Visual acuities, graft failure rates, and endothelial cell loss were comparable with the findings of studies performed for conventional PK. The technique described avoids the open-sky condition during the entire PK procedure. Endothelial cell loss rates are acceptable.

Probing magnetic helicity with synchrotron radiation and Faraday rotation

NASA Astrophysics Data System (ADS)

Oppermann, N.; Junklewitz, H.; Robbers, G.; Enßlin, T. A.

2011-06-01

We present a first application of the recently proposed LITMUS test for magnetic helicity, as well as a thorough study of its applicability under different circumstances. In order to apply this test to the galactic magnetic field, the newly developed critical filter formalism is used to produce an all-sky map of the Faraday depth. The test does not detect helicity in the galactic magnetic field. To understand the significance of this finding, we made an applicability study, showing that a definite conclusion about the absence of magnetic helicity in the galactic field has not yet been reached. This study is conducted by applying the test to simulated observational data. We consider simulations in a flat sky approximation and all-sky simulations, both with assumptions of constant electron densities and realistic distributions of thermal and cosmic ray electrons. Our results suggest that the LITMUS test does indeed perform very well in cases where constant electron densities can be assumed, both in the flat-sky limit and in the galactic setting. Non-trivial distributions of thermal and cosmic ray electrons, however, may complicate the scenario to the point where helicity in the magnetic field can escape detection.

Characterization of sun and sky glint from wind ruffled sea surfaces for improved estimation of polarized remote sensing reflectance

NASA Astrophysics Data System (ADS)

Foster, Robert; Ibrahim, Amir; Gilerson, Alex; El-Habashi, Ahmed; Carrizo, Carlos; Ahmed, Sam

2015-09-01

During two cruises in 2014, the polarized radiance of the ocean and the sky were continuously acquired using a HyperSAS-POL system. The system consists of seven hyperspectral radiometric sensors, three of which (one unpolarized and two polarized) look at the water and similarly three at the sky. The system autonomously tracks the Sun position and the heading of the research vessel to which it is attached in order to maintain a fixed relative azimuth angle with respect to the Sun (i.e. 90°) and therefore avoid the specular reflection of the sunlight. For the duration of both cruises, (NASA Ship Aircraft Bio-Optical Research (SABOR), and NOAA VIIRS Validation/Calibration), in situ inherent optical properties (IOPs) were continuously acquired using a set of instrument packages modified for underway measurement, and hyperspectral radiometric measurements were taken manually at all stations. During SABOR, an underwater polarimeter was deployed when conditions permitted. All measurements were combined in an effort to first develop a glint (sky + Sun) correction scheme for the upwelling polarized signal from a wind driven ocean surface and compare with one assuming that the ocean surface is flat.

Effects of skylight polarization, cloudiness, and view angle on the detection of oil on water.

NASA Technical Reports Server (NTRS)

Millard, J. P.; Arvesen, J. C.

1971-01-01

Three passive radiometric techniques, which use the contrast of sunlight reflected and backscattered from oil and water in specific wavelength regions, have potential application for remote sensing of oil spills. These techniques consist of measuring (1) total radiance, (2) the polarization components (normal and parallel) of radiance, and (3) the difference between the normal and parallel components. In this paper, the best view directions for these techniques are evaluated, conclusions are drawn as to the most promising technique, and explanations are developed to describe why previous total-radiance measurements yielded highest contrast between oil and water under overcast skies. The technique based on measurement of only the normal polorization component appears to be the most promising. The differential technique should be further investigated because of its potential to reduce the component of backscattered light from below the surface of the water. Measurements should be made about 45 deg nadir view angle in the direction opposite the sun. Overcast sky conditions provide a higher intensity of skylight relative to clear sky conditions and a lower intensity of backscatter within the water relative to surface reflectance. These factors result in higher contrast between oil and water under overcast skies.

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.

Controlling sunbathing safety during the summer holidays - The solar UV campaign at Baltic Sea coast in 2015.

PubMed

Guzikowski, Jakub; Czerwińska, Agnieszka E; Krzyścin, Janusz W; Czerwiński, Michał A

2017-08-01

Information regarding the intensity of surface UV radiation, provided for the public, is frequently given in terms of a daily maximum UV Index (UVI), based on a prognostic model. The quality of the UV forecast depends on the accuracy of column amount of ozone and cloudiness prediction. Daily variability of UVI is needed to determine the risk of the UV overexposure during outdoor activities. Various methods of estimating the temporary UVI and the maximum duration of UV exposures (received a dose equal to minimal erythemal dose - MED), at the site of sunbathing, were compared. The UV indices were obtained during a field experiment at the Baltic Sea coast in the period from 13th to 24th July 2015. The following UVI calculation models were considered: UVI measurements by simple hand-held biometers (Silver Crest, Oregon Scientific, or more advanced Solarmeter 6.5), our smartphone models based on cloud cover observations at the site and the cloudless-sky UVI forecast (available for any site for all smartphone users) or measured UVI, and the 24h weather predictions by the ensemble set of 10 models (with various cloud parameterizations). The direct UV measurements, even by a simple biometer, provided useful UVI estimates. The smartphone applications yielded a good agreement with the UV measurements. The weather prediction models for cloudless-sky conditions could provide valuable information if almost cloudless-sky conditions (cloudless-sky or slightly scattered clouds) were observed at the sunbathing site. Copyright © 2017 Elsevier B.V. All rights reserved.

Techniques for identifying dust devils in mars pathfinder images

USGS Publications Warehouse

Metzger, S.M.; Carr, J.R.; Johnson, J. R.; Parker, T.J.; Lemmon, M.T.

2000-01-01

Image processing methods used to identify and enhance dust devil features imaged by IMP (Imager for Mars Pathfinder) are reviewed. Spectral differences, visible red minus visible blue, were used for initial dust devil searches, driven by the observation that Martian dust has high red and low blue reflectance. The Martian sky proved to be more heavily dust-laden than pre-Pathfinder predictions, based on analysis of images from the Hubble Space Telescope. As a result, these initial spectral difference methods failed to contrast dust devils with background dust haze. Imager artifacts (dust motes on the camera lens, flat-field effects caused by imperfections in the CCD, and projection onto a flat sensor plane by a convex lens) further impeded the ability to resolve subtle dust devil features. Consequently, reference images containing sky with a minimal horizon were first subtracted from each spectral filter image to remove camera artifacts and reduce the background dust haze signal. Once the sky-flat preprocessing step was completed, the red-minus-blue spectral difference scheme was attempted again. Dust devils then were successfully identified as bright plumes. False-color ratios using calibrated IMP images were found useful for visualizing dust plumes, verifying initial discoveries as vortex-like features. Enhancement of monochromatic (especially blue filter) images revealed dust devils as silhouettes against brighter background sky. Experiments with principal components transformation identified dust devils in raw, uncalibrated IMP images and further showed relative movement of dust devils across the Martian surface. A variety of methods therefore served qualitative and quantitative goals for dust plume identification and analysis in an environment where such features are obscure.

Monopole and dipole estimation for multi-frequency sky maps by linear regression

NASA Astrophysics Data System (ADS)

Wehus, I. K.; Fuskeland, U.; Eriksen, H. K.; Banday, A. J.; Dickinson, C.; Ghosh, T.; Górski, K. M.; Lawrence, C. R.; Leahy, J. P.; Maino, D.; Reich, P.; Reich, W.

2017-01-01

We describe a simple but efficient method for deriving a consistent set of monopole and dipole corrections for multi-frequency sky map data sets, allowing robust parametric component separation with the same data set. The computational core of this method is linear regression between pairs of frequency maps, often called T-T plots. Individual contributions from monopole and dipole terms are determined by performing the regression locally in patches on the sky, while the degeneracy between different frequencies is lifted whenever the dominant foreground component exhibits a significant spatial spectral index variation. Based on this method, we present two different, but each internally consistent, sets of monopole and dipole coefficients for the nine-year WMAP, Planck 2013, SFD 100 μm, Haslam 408 MHz and Reich & Reich 1420 MHz maps. The two sets have been derived with different analysis assumptions and data selection, and provide an estimate of residual systematic uncertainties. In general, our values are in good agreement with previously published results. Among the most notable results are a relative dipole between the WMAP and Planck experiments of 10-15μK (depending on frequency), an estimate of the 408 MHz map monopole of 8.9 ± 1.3 K, and a non-zero dipole in the 1420 MHz map of 0.15 ± 0.03 K pointing towards Galactic coordinates (l,b) = (308°,-36°) ± 14°. These values represent the sum of any instrumental and data processing offsets, as well as any Galactic or extra-Galactic component that is spectrally uniform over the full sky.

CMB-S4 and the hemispherical variance anomaly

NASA Astrophysics Data System (ADS)

O'Dwyer, Márcio; Copi, Craig J.; Knox, Lloyd; Starkman, Glenn D.

2017-09-01

Cosmic microwave background (CMB) full-sky temperature data show a hemispherical asymmetry in power nearly aligned with the Ecliptic. In real space, this anomaly can be quantified by the temperature variance in the Northern and Southern Ecliptic hemispheres, with the Northern hemisphere displaying an anomalously low variance while the Southern hemisphere appears unremarkable [consistent with expectations from the best-fitting theory, Lambda Cold Dark Matter (ΛCDM)]. While this is a well-established result in temperature, the low signal-to-noise ratio in current polarization data prevents a similar comparison. This will change with a proposed ground-based CMB experiment, CMB-S4. With that in mind, we generate realizations of polarization maps constrained by the temperature data and predict the distribution of the hemispherical variance in polarization considering two different sky coverage scenarios possible in CMB-S4: full Ecliptic north coverage and just the portion of the North that can be observed from a ground-based telescope at the high Chilean Atacama plateau. We find that even in the set of realizations constrained by the temperature data, the low Northern hemisphere variance observed in temperature is not expected in polarization. Therefore, observing an anomalously low variance in polarization would make the hypothesis that the temperature anomaly is simply a statistical fluke more unlikely and thus increase the motivation for physical explanations. We show, within ΛCDM, how variance measurements in both sky coverage scenarios are related. We find that the variance makes for a good statistic in cases where the sky coverage is limited, however, full northern coverage is still preferable.

Automatic color preference correction for color reproduction

NASA Astrophysics Data System (ADS)

Tsukada, Masato; Funayama, Chisato; Tajima, Johji

2000-12-01

The reproduction of natural objects in color images has attracted a great deal of attention. Reproduction more pleasing colors of natural objects is one of the methods available to improve image quality. We developed an automatic color correction method to maintain preferred color reproduction for three significant categories: facial skin color, green grass and blue sky. In this method, a representative color in an object area to be corrected is automatically extracted from an input image, and a set of color correction parameters is selected depending on the representative color. The improvement in image quality for reproductions of natural image was more than 93 percent in subjective experiments. These results show the usefulness of our automatic color correction method for the reproduction of preferred colors.

KSC-97PC1695

NASA Image and Video Library

1997-11-19

Like a rising sun lighting up the afternoon sky, the Space Shuttle Columbia soars from Launch Pad 39B at 2:46:00 p.m. EST, November 19, on the fourth flight of the United States Microgravity Payload and Spartan-201 satellite. The crew members include Mission Commander Kevin Kregel.; Pilot Steven Lindsey; Mission Specialists Kalpana Chawla, Ph.D., Winston Scott, and Takao Doi, Ph.D., of the National Space Development Agency of Japan; and Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine. During the 16-day STS-87 mission, the crew will oversee experiments in microgravity; deploy and retrieve a solar satellite; and test a new experimental camera, the AERCam Sprint. Dr. Doi and Scott also will perform a spacewalk to practice International Space Station maneuvers

KSC-97PC1701

NASA Image and Video Library

1997-11-19

Like a rising sun lighting up the afternoon sky, the Space Shuttle Columbia soars from Launch Pad 39B at 2:46:00 p.m. EST, November 19, on the fourth flight of the United States Microgravity Payload and Spartan-201 satellite. The crew members include Mission Commander Kevin Kregel.; Pilot Steven Lindsey; Mission Specialists Kalpana Chawla, Ph.D., Winston Scott, and Takao Doi, Ph.D., of the National Space Development Agency of Japan; and Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine. During the 16-day STS-87 mission, the crew will oversee experiments in microgravity; deploy and retrieve a solar satellite; and test a new experimental camera, the AERCam Sprint. Dr. Doi and Scott also will perform a spacewalk to practice International Space Station maneuvers

KSC-97PC1700

NASA Image and Video Library

1997-11-19

Like a rising sun lighting up the afternoon sky, the Space Shuttle Columbia soars from Launch Pad 39B at 2:46:00 p.m. EST, November 19, on the fourth flight of the United States Microgravity Payload and Spartan-201 satellite. The crew members include Mission Commander Kevin Kregel.; Pilot Steven Lindsey; Mission Specialists Kalpana Chawla, Ph.D., Winston Scott, and Takao Doi, Ph.D., of the National Space Development Agency of Japan; and Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine. During the 16-day STS-87 mission, the crew will oversee experiments in microgravity; deploy and retrieve a solar satellite; and test a new experimental camera, the AERCam Sprint. Dr. Doi and Scott also will perform a spacewalk to practice International Space Station maneuvers