WorldWideScience

Sample records for space based observations

  1. Space-based pseudo-fixed latitude observation mode based on the characteristics of geosynchronous orbit belt

    Science.gov (United States)

    Hu, Yun-peng; Chen, Lei; Huang, Jian-yu

    2017-08-01

    The US Lincoln Laboratory proved that space-based visible (SBV) observation is efficient to observe space objects, especially Geosynchronous Orbit (GEO) objects. After that, SBV observation plays an important role in the space surveillance. In this paper, a novel space-based observation mode is designed to observe all the GEO objects in a relatively short time. A low earth orbit (LEO) satellite, especially a dawn-dusk sun-synchronous orbit satellite, is useful for space-based observation. Thus, the observation mode for GEO objects is based on a dawn-dusk sun-synchronous orbit satellite. It is found that the Pinch Point (PP) regions proposed by the US Lincoln Laboratory are spreading based on the analysis of the evolution principles of GEO objects. As the PP regions becoming more and more widely in the future, many strategies based on it may not be efficient any more. Hence, the key point of the space-based observation strategy design for GEO objects should be emphasized on the whole GEO belt as far as possible. The pseudo-fixed latitude observation mode is proposed in this paper based on the characteristics of GEO belt. Unlike classical space-based observation modes, pseudo-fixed latitude observation mode makes use of the one-dimensional attitude adjustment of the observation satellite. The pseudo-fixed latitude observation mode is more reliable and simple in engineering, compared with the gazing observation mode which needs to adjust the attitude from the two dimensions. It includes two types of attitude adjustment, i.e. daily and continuous attitude adjustment. Therefore, the pseudo-fixed latitude observation mode has two characteristics. In a day, the latitude of the observation region is fixed and the scanning region is about a rectangle, while the latitude of the observation region centre changes each day in a long term based on a daily strategy. The capabilities of a pseudo-fixed latitude observation instrument with a 98° dawn-dusk sun-synchronous orbit are

  2. Automated Detection of Small Bodies by Space Based Observation

    Science.gov (United States)

    Bidstrup, P. R.; Grillmayer, G.; Andersen, A. C.; Haack, H.; Jorgensen, J. L.

    The number of known comets and asteroids is increasing every year. Up till now this number is including approximately 250,000 of the largest minor planets, as they are usually referred. These discoveries are due to the Earth-based observation which has intensified over the previous decades. Additionally larger telescopes and arrays of telescopes are being used for exploring our Solar System. It is believed that all near- Earth and Main-Belt asteroids of diameters above 10 to 30 km have been discovered, leaving these groups of objects as observationally complete. However, the cataloguing of smaller bodies is incomplete as only a very small fraction of the expected number has been discovered. It is estimated that approximately 1010 main belt asteroids in the size range 1 m to 1 km are too faint to be observed using Earth-based telescopes. In order to observe these small bodies, space-based search must be initiated to remove atmospheric disturbances and to minimize the distance to the asteroids and thereby minimising the requirement for long camera integration times. A new method of space-based detection of moving non-stellar objects is currently being developed utilising the Advanced Stellar Compass (ASC) built for spacecraft attitude determination by Ørsted, Danish Technical University. The ASC serves as a backbone technology in the project as it is capable of fully automated distinction of known and unknown celestial objects. By only processing objects of particular interest, i.e. moving objects, it will be possible to discover small bodies with a minimum of ground control, with the ultimate ambition of a fully automated space search probe. Currently, the ASC is being mounted on the Flying Laptop satellite of the Institute of Space Systems, Universität Stuttgart. It will, after a launch into a low Earth polar orbit in 2008, test the detection method with the ASC equipment that already had significant in-flight experience. A future use of the ASC based automated

  3. The CEOS Atmospheric Composition Constellation: Enhancing the Value of Space-Based Observations

    Science.gov (United States)

    Eckman, Richard; Zehner, Claus; Al-Saadi, Jay

    2015-01-01

    The Committee on Earth Observation Satellites (CEOS) coordinates civil space-borne observations of the Earth. Participating agencies strive to enhance international coordination and data exchange and to optimize societal benefit. In recent years, CEOS has collaborated closely with the Group on Earth Observations (GEO) in implementing the Global Earth Observing System of Systems (GEOSS) space-based objectives. The goal of the CEOS Atmospheric Composition Constellation (ACC) is to collect and deliver data to improve monitoring, assessment and predictive capabilities for changes in the ozone layer, air quality and climate forcing associated with changes in the environment through coordination of existing and future international space assets. A project to coordinate and enhance the science value of a future constellation of geostationary sensors measuring parameters relevant to air quality supports the forthcoming European Sentinel-4, Korean GEMS, and US TEMPO missions. Recommendations have been developed for harmonization to mutually improve data quality and facilitate widespread use of the data products.

  4. CEOS contributions to informing energy management and policy decision making using space-based Earth observations

    International Nuclear Information System (INIS)

    Eckman, Richard S.; Stackhouse, Paul W.

    2012-01-01

    Earth observations are playing an increasingly significant role in informing decision making in the energy sector. In renewable energy applications, space-based observations now routinely augment sparse ground-based observations used as input for renewable energy resource assessment applications. As one of the nine Group on Earth Observations (GEO) societal benefit areas, the enhancement of management and policy decision making in the energy sector is receiving attention in activities conducted by the Committee on Earth Observation Satellites (CEOS). CEOS has become the “space arm” for the implementation of the Global Earth Observation System of Systems (GEOSS) vision. It is directly supporting the space-based, near-term tasks articulated in the GEO three-year work plan. This paper describes a coordinated program of demonstration projects conducted by CEOS member agencies and partners to utilize Earth observations to enhance energy management end-user decision support systems. We discuss the importance of engagement with stakeholders and understanding their decision support needs in successfully increasing the uptake of Earth observation products for societal benefit. Several case studies are presented, demonstrating the importance of providing data sets in formats and units familiar and immediately usable by decision makers. These projects show the utility of Earth observations to enhance renewable energy resource assessment in the developing world, forecast space weather impacts on the power grid, and improve energy efficiency in the built environment.

  5. CEOS Contributions to Informing Energy Management and Policy Decision Making Using Space-Based Earth Observations

    Science.gov (United States)

    Eckman, Richard S.

    2009-01-01

    Earth observations are playing an increasingly significant role in informing decision making in the energy sector. In renewable energy applications, space-based observations now routinely augment sparse ground-based observations used as input for renewable energy resource assessment applications. As one of the nine Group on Earth Observations (GEO) societal benefit areas, the enhancement of management and policy decision making in the energy sector is receiving attention in activities conducted by the Committee on Earth Observation Satellites (CEOS). CEOS has become the "space arm" for the implementation of the Global Earth Observation System of Systems (GEOSS) vision. It is directly supporting the space-based, near-term tasks articulated in the GEO three-year work plan. This paper describes a coordinated program of demonstration projects conducted by CEOS member agencies and partners to utilize Earth observations to enhance energy management end-user decision support systems. I discuss the importance of engagement with stakeholders and understanding their decision support needs in successfully increasing the uptake of Earth observation products for societal benefit. Several case studies are presented, demonstrating the importance of providing data sets in formats and units familiar and immediately usable by decision makers. These projects show the utility of Earth observations to enhance renewable energy resource assessment in the developing world, forecast space-weather impacts on the power grid, and improve energy efficiency in the built environment.

  6. OGLE-2016-BLG-0168 Binary Microlensing Event: Prediction and Confirmation of the Microlens Parallax Effect from Space-based Observations

    Energy Technology Data Exchange (ETDEWEB)

    Shin, I.-G.; Yee, J. C.; Jung, Y. K. [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Udalski, A.; Skowron, J.; Mróz, P.; Soszyński, I.; Poleski, R.; Szymański, M. K.; Kozłowski, S.; Pietrukowicz, P.; Ulaczyk, K.; Pawlak, M. [Warsaw University Observatory, Al. Ujazdowskie 4,00-478 Warszawa (Poland); Novati, S. Calchi [IPAC, Mail Code 100-22, California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA 91125 (United States); Han, C. [Department of Physics, Chungbuk National University, Cheongju 371-763 (Korea, Republic of); Albrow, M. D. [University of Canterbury, Department of Physics and Astronomy, Private Bag 4800, Christchurch 8020 (New Zealand); Gould, A. [Department of Astronomy, Ohio State University, 140 W. 18th Avenue, Columbus, OH 43210 (United States); Chung, S.-J.; Hwang, K.-H.; Ryu, Y.-H. [Korea Astronomy and Space Science Institute, 776 Daedeokdae-ro, Yuseong-Gu, Daejeon 34055 (Korea, Republic of); Collaboration: OGLE Collaboration; KMTNet Group; Spitzer Team; and others

    2017-11-01

    The microlens parallax is a crucial observable for conclusively identifying the nature of lens systems in microlensing events containing or composed of faint (even dark) astronomical objects such as planets, neutron stars, brown dwarfs, and black holes. With the commencement of a new era of microlensing in collaboration with space-based observations, the microlens parallax can be routinely measured. In addition, space-based observations can provide opportunities to verify the microlens parallax measured from ground-only observations and to find a unique solution to the lensing light-curve analysis. Furthermore, since most space-based observations cannot cover the full light curves of lensing events, it is also necessary to verify the reliability of the information extracted from fragmentary space-based light curves. We conduct a test based on the microlensing event OGLE-2016-BLG-0168, created by a binary lens system consisting of almost equal mass M-dwarf stars, to demonstrate that it is possible to verify the microlens parallax and to resolve degeneracies using the space-based light curve even though the observations are fragmentary. Since space-based observatories will frequently produce fragmentary light curves due to their short observing windows, the methodology of this test will be useful for next-generation microlensing experiments that combine space-based and ground-based collaboration.

  7. A phase-space approach to atmospheric dynamics based on observational data. Theory and applications

    International Nuclear Information System (INIS)

    Wang Risheng.

    1994-01-01

    This thesis is an attempt to develop systematically a phase-space approach to the atmospheric dynamics based on the theoretical achievement and application experiences in nonlinear time-series analysis. In particular, it is concerned with the derivation of quantities for describing the geometrical structure of the observed dynamics in phase-space (dimension estimation) and the examination of the observed atmospheric fluctuations in the light of phase-space representation. The thesis is, therefore composed of three major parts, i.e. an general survey of the theory of statistical approaches to dynamic systems, the methodology designed for the present study and specific applications with respect to dimension estimation and to a phase-space analysis of the tropical stratospheric quasi-biennial oscillation. (orig./KW)

  8. Understanding the Longitudinal Variability of Equatorial Electrodynamics using integrated Ground- and Space-based Observations

    Science.gov (United States)

    Yizengaw, E.; Moldwin, M.; Zesta, E.

    2015-12-01

    The currently funded African Meridian B-Field Education and Research (AMBER) magnetometer array comprises more than thirteen magnetometers stationed globally in the vicinity of geomagnetic equator. One of the main objectives of AMBER network is to understand the longitudinal variability of equatorial electrodynamics as function of local time, magnetic activity, and season. While providing complete meridian observation in the region and filling the largest land-based gap in global magnetometer coverage, the AMBER array addresses two fundamental areas of space physics: first, the processes governing electrodynamics of the equatorial ionosphere as a function of latitude (or L-shell), local time, longitude, magnetic activity, and season, and second, ULF pulsation strength at low/mid-latitude regions and its connection with equatorial electrojet and density fluctuation. The global AMBER network can also be used to augment observations from space-based instruments, such us the triplet SWARM mission and the upcoming ICON missions. Thus, in coordination with space-based and other ground-based observations, the AMBER magnetometer network provides a great opportunity to understand the electrodynamics that governs equatorial ionosphere motions. In this paper we present the longitudinal variability of the equatorial electrodynamics using the combination of instruments onboard SWARM and C/NOFS satellites and ground-based AMBER network. Both ground- and pace-based observations show stronger dayside and evening sector equatorial electrodynamics in the American and Asian sectors compared to the African sector. On the other hand, the African sector is home to stronger and year-round ionospheric bubbles/irregularities compared to the American and Asian sectors. This raises the question if the evening sector equatorial electrodynamics (vertical drift), which is believed to be the main cause for the enhancement of Rayleigh-Taylor (RT) instability growth rate, is stronger in the

  9. Approaching control for tethered space robot based on disturbance observer using super twisting law

    Science.gov (United States)

    Hu, Yongxin; Huang, Panfeng; Meng, Zhongjie; Wang, Dongke; Lu, Yingbo

    2018-05-01

    Approaching control is a key mission for the tethered space robot to perform the task of removing space debris. But the uncertainties of the TSR such as the change of model parameter have an important effect on the approaching mission. Considering the space tether and the attitude of the gripper, the dynamic model of the TSR is derived using Lagrange method. Then a disturbance observer is designed to estimate the uncertainty based on STW control method. Using the disturbance observer, a controller is designed, and the performance is compared with the dynamic inverse controller which turns out that the proposed controller performs better. Numerical simulation validates the feasibility of the proposed controller on the position and attitude tracking of the TSR.

  10. Prospects for Observing Ultracompact Binaries with Space-Based Gravitational Wave Interferometers and Optical Telescopes

    Science.gov (United States)

    Littenberg, T. B.; Larson, S. L.; Nelemans, G.; Cornish, N. J.

    2012-01-01

    Space-based gravitational wave interferometers are sensitive to the galactic population of ultracompact binaries. An important subset of the ultracompact binary population are those stars that can be individually resolved by both gravitational wave interferometers and electromagnetic telescopes. The aim of this paper is to quantify the multimessenger potential of space-based interferometers with arm-lengths between 1 and 5 Gm. The Fisher information matrix is used to estimate the number of binaries from a model of the Milky Way which are localized on the sky by the gravitational wave detector to within 1 and 10 deg(exp 2) and bright enough to be detected by a magnitude-limited survey.We find, depending on the choice ofGW detector characteristics, limiting magnitude and observing strategy, that up to several hundred gravitational wave sources could be detected in electromagnetic follow-up observations.

  11. Distributed Space Mission Design for Earth Observation Using Model-Based Performance Evaluation

    Science.gov (United States)

    Nag, Sreeja; LeMoigne-Stewart, Jacqueline; Cervantes, Ben; DeWeck, Oliver

    2015-01-01

    Distributed Space Missions (DSMs) are gaining momentum in their application to earth observation missions owing to their unique ability to increase observation sampling in multiple dimensions. DSM design is a complex problem with many design variables, multiple objectives determining performance and cost and emergent, often unexpected, behaviors. There are very few open-access tools available to explore the tradespace of variables, minimize cost and maximize performance for pre-defined science goals, and therefore select the most optimal design. This paper presents a software tool that can multiple DSM architectures based on pre-defined design variable ranges and size those architectures in terms of predefined science and cost metrics. The tool will help a user select Pareto optimal DSM designs based on design of experiments techniques. The tool will be applied to some earth observation examples to demonstrate its applicability in making some key decisions between different performance metrics and cost metrics early in the design lifecycle.

  12. Global Space Weather Observational Network: Challenges and China's Contribution

    Science.gov (United States)

    Wang, C.

    2017-12-01

    To understand space weather physical processes and predict space weather accurately, global space-borne and ground-based space weather observational network, making simultaneous observations from the Sun to geo-space (magnetosphere, ionosphere and atmosphere), plays an essential role. In this talk, we will present the advances of the Chinese space weather science missions, including the ASO-S (Advanced Space-borne Solar Observatory), MIT (Magnetosphere - Ionosphere- Thermosphere Coupling Exploration), and the ESA-China joint space weather science mission SMILE (Solar wind - Magnetosphere - Ionosphere Link Explore), a new mission to image the magnetosphere. Compared to satellites, ground-based monitors are cheap, convenient, and provide continuous real-time data. We will also introduce the Chinese Meridian Project (CMP), a ground-based program fully utilizing the geographic location of the Chinese landmass to monitor the geo-space environment. CMP is just one arm of a larger program that Chinese scientists are proposing to the international community. The International Meridian Circle Program (IMCP) for space weather hopes to connect chains of ground-based monitors at the longitudinal meridians 120 deg E and 60 deg W. IMCP takes advantage of the fact that these meridians already have the most monitors of any on Earth, with monitors in Russia, Australia, Brazil, the United States, Canada, and other countries. This data will greatly enhance the ability of scientists to monitor and predict the space weather worldwide.

  13. Observing the Anthropocene from Space

    Science.gov (United States)

    Dittus, Hansjörg

    2016-07-01

    Influence of mankind on Earth's climate is evident. The growing population using the resources available, especially by burning goal, oil and gas, changes the composition of the Earth's atmosphere with the result of a continuously increasing temperature. Effects are not limited to the regional scale but are evident on the whole planet, meanwhile named Anthropocene. According to this global influence, it's necessary to also extend monitoring to the entire planet. Space-based observation systems are not limited by any artificial borders and are in principle able, to cover the whole Earth. In principle, two different ways of observation can be selected: Either a dedicated spacecraft will be send into low earth orbit (LEO) or existing platforms are used. Advantages of satellites are the more or less freely selectable orbit (with orbits covering also the polar regions) and the possible adaption of spacecraft platform for the dedicated instrument. On the other hand platforms like the ISS space station enable continuous long term coverage with different instruments. The drawback of an only limited coverage based on the orbit inclination is made up by the possibility to service systems on the station. Furthermore different generations of sensors can be run in parallel and therefore cross calibrated if needed. This paper reviews the currently available sensors types and discusses potential future needs. Included in this discussion is the international space station as an already available platform for earth observation. Furthermore, discussion should also take into account, that an increasing number of constellations with dozens or even thousand satellites are planned. Are these constellations also an option for an increased temporal and spatial monitoring of the Earth?

  14. Toward Microsatellite Based Space Situational Awareness

    Science.gov (United States)

    Scott, L.; Wallace, B.; Sale, M.; Thorsteinson, S.

    2013-09-01

    The NEOSSat microsatellite is a dual mission space telescope which will perform asteroid detection and Space Situational Awareness (SSA) observation experiments on deep space, earth orbiting objects. NEOSSat was launched on 25 February 2013 into a 800 dawn-dusk sun synchronous orbit and is currently undergoing satellite commissioning. The microsatellite consists of a small aperture optical telescope, GPS receiver, high performance attitude control system, and stray light rejection baffle designed to reject stray light from the Sun while searching for asteroids with elongations 45 degrees along the ecliptic. The SSA experimental mission, referred to as HEOSS (High Earth Orbit Space Surveillance), will focus on objects in deep space orbits. The HEOSS mission objective is to evaluate the utility of microsatellites to perform catalog maintenance observations of resident space objects in a manner consistent with the needs of the Canadian Forces. The advantages of placing a space surveillance sensor in low Earth orbit are that the observer can conduct observations without the day-night interruption cycle experienced by ground based telescopes, the telescope is insensitive to adverse weather and the system has visibility to deep space resident space objects which are not normally visible from ground based sensors. Also, from a photometric standpoint, the microsatellite is able to conduct observations on objects with a rapidly changing observer position. The possibility of spin axis estimation on geostationary satellites may be possible and an experiment characterize spin axis of distant resident space objects is being planned. Also, HEOSS offers the ability to conduct observations of satellites at high phase angles which can potentially extend the trackable portion of space in which deep space objects' orbits can be monitored. In this paper we describe the HEOSS SSA experimental data processing system and the preliminary findings of the catalog maintenance experiments

  15. The COSPAR roadmap on Space-based observation and Integrated Earth System Science for 2016-2025

    Science.gov (United States)

    Fellous, Jean-Louis

    2016-07-01

    space-based observing systems, further long-term requirements for observations and other data, technological advances and data challenges, and the importance of enhanced international cooperation.

  16. Observations from Space and the Future of Meteorology

    Science.gov (United States)

    Tepper, Morris

    1974-01-01

    Describes space-based observations and other aspects of meterology that will enable weather forecasters to lengthen the scale of predictability from the current day-to-day basis to one week or longer. (Author/GS)

  17. Fifty Years of Lightning Observations from Space

    Science.gov (United States)

    Christian, H. J., Jr.

    2017-12-01

    Some of the earliest satellites, starting with OSO (1965), ARIEL (1967), and RAE (1968), detected lightning using either optical and RF sensors, although that was not their intent. One of the earliest instruments designed to detect lightning was the PBE (1977). The use of space to study lightning activity has exploded since these early days. The advent of focal-plane imaging arrays made it possible to develop high performance optical lightning sensors. Prior to the use of charged-coupled devices (CCD), most space-based lightning sensors used only a few photo-diodes, which limited the location accuracy and detection efficiency (DE) of the instruments. With CCDs, one can limit the field of view of each detector (pixel), and thus improve the signal to noise ratio over single-detectors that summed the light reflected from many clouds with the lightning produced by a single cloud. This pixelization enabled daytime DE to increase from a few percent to close to 90%. The OTD (1995), and the LIS (1997), were the first lightning sensors to utilize focal-plane arrays. Together they detected global lightning activity for more than twenty years, providing the first detailed information on the distribution of global lightning and its variability. The FORTE satellite was launched shortly after LIS, and became the first dedicated satellite to simultaneously measure RF and optical lightning emissions. It too used a CCD focal plane to detect and locate lightning. In November 2016, the GLM became the first lightning instrument in geostationary orbit. Shortly thereafter, China placed its GLI in orbit. Lightning sensors in geostationary orbit significantly increase the value of space-based observations. For the first time, lightning activity can be monitored continuously, over large areas of the Earth with high, uniform DE and location accuracy. In addition to observing standard lightning, a number of sensors have been placed in orbit to detect transient luminous events and

  18. Earth observations from space: the first 50 years of scientific achievements

    National Research Council Canada - National Science Library

    Committee on Scientific Accomplishments of Earth Observations from Space, National Research Council

    .... At the request of the National Aeronautics and Space Administration, the National Research Council convened a committee to examine the scientific accomplishments that have resulted from space-based observations...

  19. The magnetic field of the earth - Performance considerations for space-based observing systems

    Science.gov (United States)

    Webster, W. J., Jr.; Taylor, P. T.; Schnetzler, C. C.; Langel, R. A.

    1985-01-01

    Basic problems inherent in carrying out observations of the earth magnetic field from space are reviewed. It is shown that while useful observations of the core and crustal fields are possible at the peak of the solar cycle, the greatest useful data volume is obtained during solar minimum. During the last three solar cycles, the proportion of data with a planetary disturbance index of less than 2 at solar maximum was in the range 0.4-0.8 in comparison with solar minimum. It is found that current state of the art orbit determination techniques should eliminate orbit error as a problem in gravitational field measurements from space. The spatial resolution obtained for crustal field anomalies during the major satellite observation programs of the last 30 years are compared in a table. The relationship between observing altitude and the spatial resolution of magnetic field structures is discussed. Reference is made to data obtained using the Magsat, the Polar Orbiting Geophysical Observatory (POGO), and instruments on board the Space Shuttle.

  20. SPACE-BASED MICROLENS PARALLAX OBSERVATION AS A WAY TO RESOLVE THE SEVERE DEGENERACY BETWEEN MICROLENS-PARALLAX AND LENS-ORBITAL EFFECTS

    Energy Technology Data Exchange (ETDEWEB)

    Han, C. [Department of Physics, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Udalski, A.; Szymański, M. K.; Soszyński, I.; Skowron, J.; Mróz, P.; Poleski, R.; Pietrukowicz, P.; Kozłowski, S.; Ulaczyk, K.; Wyrzykowski, Ł.; Pawlak, M. [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Lee, C.-U.; Gould, A.; Chung, S.-J.; Kim, S.-L.; Cha, S.-M. [Korea Astronomy and Space Science Institute, Daejeon 34055 (Korea, Republic of); Bozza, V. [Dipartimento di Fisica “E. R. Caianiello”, Uńiversitá di Salerno, Via Giovanni Paolo II, I-84084 Fisciano (Italy); Albrow, M. D. [University of Canterbury, Department of Physics and Astronomy, Private Bag 4800, Christchurch 8020 (New Zealand); Jung, Y. K. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA, 02138 (United States); Collaboration: OGLE Collaboration; KMTNet Collaboration; and others

    2016-08-10

    In this paper, we demonstrate the severity of the degeneracy between the microlens-parallax and lens-orbital effects by presenting the analysis of the gravitational binary-lens event OGLE-2015-BLG-0768. Despite the obvious deviation from the model based on the linear observer motion and the static binary, it is found that the residual can be almost equally well explained by either the parallactic motion of the Earth or the rotation of the binary-lens axis, resulting in the severe degeneracy between the two effects. We show that the degeneracy can be readily resolved with the additional data provided by space-based microlens parallax observations. By enabling us to distinguish between the two higher-order effects, space-based microlens parallax observations will not only make it possible to accurately determine the physical lens parameters but also to further constrain the orbital parameters of binary lenses.

  1. OGLE-2015-BLG-0479LA,B: BINARY GRAVITATIONAL MICROLENS CHARACTERIZED BY SIMULTANEOUS GROUND-BASED AND SPACE-BASED OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Han, C. [Department of Physics, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Udalski, A.; Szymański, M. K.; Soszyński, I.; Skowron, J.; Mróz, P.; Poleski, R. [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Gould, A.; Zhu, Wei; Fausnaugh, M.; Gaudi, B. S.; Wibking, B. [Department of Astronomy, Ohio State University, 140 W. 18th Avenue, Columbus, OH 43210 (United States); Street, R. A. [School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Yee, J. C. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Beichman, C.; Novati, S. Calchi [NASA Exoplanet Science Institute, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States); Bryden, C.; Henderson, Calen B.; Shvartzvald, Y. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Carey, S. [Spitzer Science Center, MS 220-6, California Institute of Technology, Pasadena, CA (United States); Collaboration: (The Spitzer Microlensing Team; (The OGLE Collaboration; (The RoboNet collaboration; (The MiNDSTEp Consortium; (The μ FUN Collaboration; and others

    2016-09-01

    We present a combined analysis of the observations of the gravitational microlensing event OGLE-2015-BLG-0479 taken both from the ground and by the Spitzer Space Telescope . The light curves seen from the ground and from space exhibit a time offset of ∼13 days between the caustic spikes, indicating that the relative lens-source positions seen from the two places are displaced by parallax effects. From modeling the light curves, we measure the space-based microlens parallax. Combined with the angular Einstein radius measured by analyzing the caustic crossings, we determine the mass and distance of the lens. We find that the lens is a binary composed of two G-type stars with masses of ∼1.0 M {sub ⊙} and ∼0.9 M {sub ⊙} located at a distance of ∼3 kpc. In addition, we are able to constrain the complete orbital parameters of the lens thanks to the precise measurement of the microlens parallax derived from the joint analysis. In contrast to the binary event OGLE-2014-BLG-1050, which was also observed by Spitzer, we find that the interpretation of OGLE-2015-BLG-0479 does not suffer from the degeneracy between (±, ±) and (±, ∓) solutions, confirming that the four-fold parallax degeneracy in single-lens events collapses into the two-fold degeneracy for the general case of binary-lens events. The location of the blend in the color–magnitude diagram is consistent with the lens properties, suggesting that the blend is the lens itself. The blend is bright enough for spectroscopy and thus this possibility can be checked from future follow-up observations.

  2. Observing the Global Water Cycle from Space

    Science.gov (United States)

    Hildebrand, P. H.

    2004-01-01

    This paper presents an approach to measuring all major components of the water cycle from space. Key elements of the global water cycle are discussed in terms of the storage of water-in the ocean, air, cloud and precipitation, in soil, ground water, snow and ice, and in lakes and rivers, and in terms of the global fluxes of water between these reservoirs. Approaches to measuring or otherwise evaluating the global water cycle are presented, and the limitations on known accuracy for many components of the water cycle are discussed, as are the characteristic spatial and temporal scales of the different water cycle components. Using these observational requirements for a global water cycle observing system, an approach to measuring the global water cycle from space is developed. The capabilities of various active and passive microwave instruments are discussed, as is the potential of supporting measurements from other sources. Examples of space observational systems, including TRMM/GPM precipitation measurement, cloud radars, soil moisture, sea surface salinity, temperature and humidity profiling, other measurement approaches and assimilation of the microwave and other data into interpretative computer models are discussed to develop the observational possibilities. The selection of orbits is then addressed, for orbit selection and antenna size/beamwidth considerations determine the sampling characteristics for satellite measurement systems. These considerations dictate a particular set of measurement possibilities, which are then matched to the observational sampling requirements based on the science. The results define a network of satellite instrumentation systems, many in low Earth orbit, a few in geostationary orbit, and all tied together through a sampling network that feeds the observations into a data-assimilative computer model.

  3. Estimation of High-Frequency Earth-Space Radio Wave Signals via Ground-Based Polarimetric Radar Observations

    Science.gov (United States)

    Bolen, Steve; Chandrasekar, V.

    2002-01-01

    Expanding human presence in space, and enabling the commercialization of this frontier, is part of the strategic goals for NASA's Human Exploration and Development of Space (HEDS) enterprise. Future near-Earth and planetary missions will support the use of high-frequency Earth-space communication systems. Additionally, increased commercial demand on low-frequency Earth-space links in the S- and C-band spectra have led to increased interest in the use of higher frequencies in regions like Ku and Ka-band. Attenuation of high-frequency signals, due to a precipitating medium, can be quite severe and can cause considerable disruptions in a communications link that traverses such a medium. Previously, ground radar measurements were made along the Earth-space path and compared to satellite beacon data that was transmitted to a ground station. In this paper, quantitative estimation of the attenuation along the propagation path is made via inter-comparisons of radar data taken from the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) and ground-based polarimetric radar observations. Theoretical relationships between the expected specific attenuation (k) of spaceborne measurements with ground-based measurements of reflectivity (Zh) and differential propagation phase shift (Kdp) are developed for various hydrometeors that could be present along the propagation path, which are used to estimate the two-way path-integrated attenuation (PIA) on the PR return echo. Resolution volume matching and alignment of the radar systems is performed, and a direct comparison of PR return echo with ground radar attenuation estimates is made directly on a beam-by-beam basis. The technique is validated using data collected from the TExas and Florida UNderflights (TEFLUN-B) experiment and the TRMM large Biosphere-Atmosphere experiment in Amazonia (LBA) campaign. Attenuation estimation derived from this method can be used for strategiC planning of communication systems for

  4. Conformally compactified homogeneous spaces (Possible Observable Consequences)

    International Nuclear Information System (INIS)

    Budinich, P.

    1995-01-01

    Some arguments based on the possible spontaneous violation of the Cosmological Principles (represented by the observed large-scale structures of galaxies), the Cartan-geometry of simple spinors and on the Fock-formulation of hydrogen-atom wave-equation in momentum-space, are presented in favour of the hypothesis that space-time and momentum-space should be both conformally compactified and represented by the two four-dimensional homogeneous spaces of the conformal group, both isomorphic to (S 3 X S 1 )/Z 2 and correlated by conformal inversion. Within this framework, the possible common origin for the S0(4) symmetry underlying the geometrical structure of the Universe, of Kepler orbits and of the H-atom is discussed. On of the consequences of the proposed hypothesis could be that any quantum field theory should be naturally free from both infrared and ultraviolet divergences. But then physical spaces defined as those where physical phenomena may be best described, could be different from those homogeneous spaces. A simple, exactly soluble, toy model, valid for a two-dimensional space-time is presented where the conjecture conformally compactified space-time and momentum-space are both isomorphic to (S 1 X S 1 )/Z 2 , while the physical spaces are two finite lattice which are dual since Fourier transforms, represented by finite, discrete, sums may be well defined on them. Furthermore, a q-deformed SU q (1,1) may be represented on them if q is a root of unity. (author). 22 refs, 3 figs

  5. OGLE-2015-BLG-0196: GROUND-BASED GRAVITATIONAL MICROLENS PARALLAX CONFIRMED BY SPACE-BASED OBSERVATION

    Energy Technology Data Exchange (ETDEWEB)

    Han, C. [Department of Physics, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Udalski, A.; Szymański, M. K.; Soszyński, I.; Skowron, J.; Mróz, P.; Poleski, R.; Pietrukowicz, P.; Kozłowski, S.; Ulaczyk, K.; Pawlak, M. [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Gould, A.; Zhu, Wei; Fausnaugh, M.; Gaudi, B. S. [Department of Astronomy, Ohio State University, 140 W. 18th Ave., Columbus, OH 43210 (United States); Yee, J. C. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Beichman, C. [NASA Exoplanet Science Institute, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States); Novati, S. Calchi [Dipartimento di Fisica “E. R. Caianiello,” Uńiversitá di Salerno, Via Giovanni Paolo II, I-84084 Fisciano (Italy); Carey, S. [Spitzer Science Center, MS 220-6, California Institute of Technology, Pasadena, CA (United States); Bryden, C. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109 (United States); Collaboration: OGLE Collaboration; Spitzer Microlensing Team; and others

    2017-01-01

    In this paper, we present an analysis of the binary gravitational microlensing event OGLE-2015-BLG-0196. The event lasted for almost a year, and the light curve exhibited significant deviations from the lensing model based on the rectilinear lens-source relative motion, enabling us to measure the microlens parallax. The ground-based microlens parallax is confirmed by the data obtained from space-based microlens observations using the Spitzer telescope. By additionally measuring the angular Einstein radius from the analysis of the resolved caustic crossing, the physical parameters of the lens are determined up to the twofold degeneracy, u {sub 0} < 0 and u {sub 0} > 0, solutions caused by the well-known “ecliptic” degeneracy. It is found that the binary lens is composed of two M dwarf stars with similar masses, M {sub 1} = 0.38 ± 0.04 M {sub ⊙} (0.50 ± 0.05 M {sub ⊙}) and M {sub 2} = 0.38 ± 0.04 M {sub ⊙} (0.55 ± 0.06 M {sub ⊙}), and the distance to the lens is D {sub L} = 2.77 ± 0.23 kpc (3.30 ± 0.29 kpc). Here the physical parameters outside and inside the parentheses are for the u {sub 0} < 0 and u {sub 0} > 0 solutions, respectively.

  6. Observing photons in space a guide to experimental space astronomy

    CERN Document Server

    Pauluhn, Anuschka; Culhane, J; Timothy, J; Wilhelm, Klaus; Zehnder, Alex

    2013-01-01

    An ideal resource for lecturers, this book provides a comprehensive review of experimental space astronomy. The number of astronomers whose knowledge and interest is concentrated on interpreting observations has grown substantially in the past decades; yet, the number of scientists who are familiar with and capable of dealing with instrumentation has dwindled.  All of the authors of this work are leading and experienced experts and practitioners who have designed, built, tested, calibrated, launched and operated advanced observing equipment for space astronomy. This book also contains concise information on the history of the field, supported by appropriate references. Moreover, scientists working in other fields will be able to get a quick overview of the salient issues of observing photons in any one of the various energy, wavelength and frequency ranges accessible in space. This book was written with the intention to make it accessible to advanced undergraduate and graduate students.

  7. The First Simultaneous Microlensing Observations by Two Space telescopes

    DEFF Research Database (Denmark)

    Shvartzvald, Y.; Li, Z.; Udalski, A.

    2016-01-01

    study the region of microlensing parameter space to which Swift is sensitive, finding that though Swift could not measure the microlens parallax with respect to ground-based observations for this event, it can be important for other events. Specifically, it is important for detecting nearby brown dwarfs...

  8. Space observations for global and regional studies of the biosphere

    Science.gov (United States)

    Cihlar, J.; Li, Z.; Chen, J.; Sellers, P.; Hall, F.

    1994-01-01

    The capability to make space-based measurements of Earth at high spatial and temporal resolutions, which would not otherwise be economically or practically feasible, became available just in time to contribute to scientific understanding of the interactive processes governing the total Earth system. Such understanding has now become essential in order to take practical steps which would counteract or mitigate the pervasive impact of the growing human population on the future habitability of the Earth. The paper reviews the rationale for using space observations for studies of climate and terrestrial ecosystems at global and regional scales, as well as the requirements for such observations for studies of climate and ecosystem dynamics. The present status of these developments is reported along with initiatives under way to advance the use of satellite observations for Earth system studies. The most important contribution of space observations is the provision of physical or biophysical parameters for models representing various components of the Earth system. Examples of such parameters are given for climatic and ecosystem studies.

  9. Global Earth Observation System of Systems: Characterizing Uncertainties of Space- based Measurements and Earth System Models Informing Decision Tools

    Science.gov (United States)

    Birk, R. J.; Frederick, M.

    2006-05-01

    The Global Earth Observation System of Systems (GEOSS) framework identifies the benefits of systematically and scientifically networking the capacity of organizations and systems into solutions that benefit nine societal benefit areas. The U.S. Integrated Earth Observation System (IEOS), the U.S. contribution to the GEOSS, focuses on near-term, mid-term, and long-term opportunities to establish integrated system solutions based on capacities and capabilities of member agencies and affiliations. Scientists at NASA, NOAA, DOE, NSF and other U.S. agencies are evolving the predictive capacity of models of Earth processes based on space-based, airborne and surface-based instruments and their measurements. NASA research activities include advancing the power and accessibility of computational resources (i.e. Project Columbia) to enable robust science data analysis, modeling, and assimilation techniques to rapidly advance. The integration of the resulting observations and predictions into decision support tools require characterization of the accuracies of a range of input measurements includes temperature and humidity profiles, wind speed, ocean height, sea surface temperature, and atmospheric constituents that are measured globally by U.S. deployed spacecraft. These measurements are stored in many data formats on many different information systems with widely varying accessibility and have processes whose documentation ranges from extremely detailed to very minimal. Integrated and interdisciplinary modeling (enabled by the Earth System Model Framework) enable the types of ensemble analysis that are useful for decision processes associated with energy management, public health risk assessments, and optimizing transportation safety and efficiency. Interdisciplinary approaches challenge systems integrators (both scientists and engineers) to expand beyond the traditional boundaries of particular disciplines to develop, verify and validate, and ultimately benchmark the

  10. Using the SPICE system to help plan and interpret space science observations

    Science.gov (United States)

    Acton, Charles H., Jr.

    1993-01-01

    A portable multimission information system named SPICE is used to assemble, archive, and provide easy user access to viewing geometry and other ancillary information needed by space scientists to interpret observations of bodies within our solar system. The modular nature of this system lends it to use in planning such observations as well. With a successful proof of concept on Voyager, the SPICE system has been adapted to the Magellan, Galileo and Mars Observer missions, and to a variety of ground based operations. Adaptation of SPICE for Cassini and the Russian Mars 94/96 projects is underway, and work on Cassini will follow, SPICE has been used to support observation planning for moving targets on the Hubble Space Telescope Project. Applications for SPICE on earth science, space physics and other astrophysics missions are under consideration.

  11. 33-Foot-Diameter Space Station Leading to Space Base

    Science.gov (United States)

    1969-01-01

    This picture illustrates a concept of a 33-Foot-Diameter Space Station Leading to a Space Base. In-house work of the Marshall Space Flight Center, as well as a Phase B contract with the McDornel Douglas Astronautics Company, resulted in a preliminary design for a space station in 1969 and l970. The Marshall-McDonnel Douglas approach envisioned the use of two common modules as the core configuration of a 12-man space station. Each common module was 33 feet in diameter and 40 feet in length and provided the building blocks, not only for the space station, but also for a 50-man space base. Coupled together, the two modules would form a four-deck facility: two decks for laboratories and two decks for operations and living quarters. Zero-gravity would be the normal mode of operation, although the station would have an artificial gravity capability. This general-purpose orbital facility was to provide wide-ranging research capabilities. The design of the facility was driven by the need to accommodate a broad spectrum of activities in support of astronomy, astrophysics, aerospace medicine, biology, materials processing, space physics, and space manufacturing. To serve the needs of Earth observations, the station was to be placed in a 242-nautical-mile orbit at a 55-degree inclination. An Intermediate-21 vehicle (comprised of Saturn S-IC and S-II stages) would have launched the station in 1977.

  12. Seismology and space-based geodesy

    Science.gov (United States)

    Tralli, David M.; Tajima, Fumiko

    1993-01-01

    The potential of space-based geodetic measurement of crustal deformation in the context of seismology is explored. The achievements of seismological source theory and data analyses, mechanical modeling of fault zone behavior, and advances in space-based geodesy are reviewed, with emphasis on realizable contributions of space-based geodetic measurements specifically to seismology. The fundamental relationships between crustal deformation associated with an earthquake and the geodetically observable data are summarized. The response and spatial and temporal resolution of the geodetic data necessary to understand deformation at various phases of the earthquake cycle is stressed. The use of VLBI, SLR, and GPS measurements for studying global geodynamics properties that can be investigated to some extent with seismic data is discussed. The potential contributions of continuously operating strain monitoring networks and globally distributed geodetic observatories to existing worldwide modern digital seismographic networks are evaluated in reference to mutually addressable problems in seismology, geophysics, and tectonics.

  13. Exploiting Orbital Data and Observation Campaigns to Improve Space Debris Models

    Science.gov (United States)

    Braun, V.; Horstmann, A.; Reihs, B.; Lemmens, S.; Merz, K.; Krag, H.

    The European Space Agency (ESA) has been developing the Meteoroid and Space Debris Terrestrial Environment Reference (MASTER) software as the European reference model for space debris for more than 25 years. It is an event-based simulation of all known individual debris-generating events since 1957, including breakups, solid rocket motor firings and nuclear reactor core ejections. In 2014, the upgraded Debris Risk Assessment and Mitigation Analysis (DRAMA) tool suite was released. In the same year an ESA instruction made the standard ISO 24113:2011 on space debris mitigation requirements, adopted via the European Cooperation for Space Standardization (ECSS), applicable to all ESA missions. In order to verify the compliance of a space mission with those requirements, the DRAMA software is used to assess collision avoidance statistics, estimate the remaining orbital lifetime and evaluate the on-ground risk for controlled and uncontrolled reentries. In this paper, the approach to validate the MASTER and DRAMA tools is outlined. For objects larger than 1 cm, thus potentially being observable from ground, the MASTER model has been validated through dedicated observation campaigns. Recent campaign results shall be discussed. Moreover, catalogue data from the Space Surveillance Network (SSN) has been used to correlate the larger objects. In DRAMA, the assessment of collision avoidance statistics is based on orbit uncertainty information derived from Conjunction Data Messages (CDM) provided by the Joint Space Operations Center (JSpOC). They were collected for more than 20 ESA spacecraft in the recent years. The way this information is going to be used in a future DRAMA version is outlined and the comparison of estimated manoeuvre rates with real manoeuvres from the operations of ESA spacecraft is shown.

  14. Observation of Polarization Vortices in Momentum Space

    Science.gov (United States)

    Zhang, Yiwen; Chen, Ang; Liu, Wenzhe; Hsu, Chia Wei; Wang, Bo; Guan, Fang; Liu, Xiaohan; Shi, Lei; Lu, Ling; Zi, Jian

    2018-05-01

    The vortex, a fundamental topological excitation featuring the in-plane winding of a vector field, is important in various areas such as fluid dynamics, liquid crystals, and superconductors. Although commonly existing in nature, vortices were observed exclusively in real space. Here, we experimentally observed momentum-space vortices as the winding of far-field polarization vectors in the first Brillouin zone of periodic plasmonic structures. Using homemade polarization-resolved momentum-space imaging spectroscopy, we mapped out the dispersion, lifetime, and polarization of all radiative states at the visible wavelengths. The momentum-space vortices were experimentally identified by their winding patterns in the polarization-resolved isofrequency contours and their diverging radiative quality factors. Such polarization vortices can exist robustly on any periodic systems of vectorial fields, while they are not captured by the existing topological band theory developed for scalar fields. Our work provides a new way for designing high-Q plasmonic resonances, generating vector beams, and studying topological photonics in the momentum space.

  15. Experimental Observations of Ion Phase-Space Vortices

    DEFF Research Database (Denmark)

    Pécseli, Hans; Armstrong, R. J.; Trulsen, J.

    1981-01-01

    Experimental observations of ion phase-space vortices are reported. The ion phase-space vortices form in the region of heated ions behind electrostatic ion acoustic shocks. The results are in qualitative agreement with numerical and analytic studies....

  16. Observation and simulation of AGW in Space

    Science.gov (United States)

    Kunitsyn, Vyacheslav; Kholodov, Alexander; Andreeva, Elena; Nesterov, Ivan; Padokhin, Artem; Vorontsov, Artem

    2014-05-01

    Examples are presented of satellite observations and imaging of AGW and related phenomena in space travelling ionospheric disturbances (TID). The structure of AGW perturbations was reconstructed by satellite radio tomography (RT) based on the signals of Global Navigation Satellite Systems (GNSS). The experiments use different GNSS, both low-orbiting (Russian Tsikada and American Transit) and high-orbiting (GPS, GLONASS, Galileo, Beidou). The examples of RT imaging of TIDs and AGWs from anthropogenic sources such as ground explosions, rocket launching, heating the ionosphere by high-power radio waves are presented. In the latter case, the corresponding AGWs and TIDs were generated in response to the modulation in the power of the heating wave. The natural AGW-like wave disturbances are frequently observed in the atmosphere and ionosphere in the form of variations in density and electron concentration. These phenomena are caused by the influence of the near-space environment, atmosphere, and surface phenomena including long-period vibrations of the Earth's surface, earthquakes, explosions, temperature heating, seisches, tsunami waves, etc. Examples of experimental RT reconstructions of wave disturbances associated with the earthquakes and tsunami waves are presented, and RT images of TIDs caused by the variations in the corpuscular ionization are demonstrated. The results of numerical modeling of AGW generation by some surface and volume sources are discussed. The milli-Hertz AGWs generated by these sources induce perturbations with a typical scale of a few hundred of kilometers at the heights of the middle atmosphere and ionosphere. The numerical modeling is based on the solution of equations of geophysical hydrodynamics. The results of the numerical simulations agree with the observations. The authors acknowledge the support of the Russian Foundation for Basic Research (grants 14-05-00855 and 13-05-01122), grant of the President of Russian Federation MK-2670

  17. Internationally coordinated multi-mission planning is now critical to sustain the space-based rainfall observations needed for managing floods globally

    International Nuclear Information System (INIS)

    Reed, Patrick M; Herman, Jonathan D; Chaney, Nathaniel W; Wood, Eric F; Ferringer, Matthew P

    2015-01-01

    At present 4 of 10 dedicated rainfall observing satellite systems have exceeded their design life, some by more than a decade. Here, we show operational implications for flood management of a ‘collapse’ of space-based rainfall observing infrastructure as well as the high-value opportunities for a globally coordinated portfolio of satellite missions and data services. Results show that the current portfolio of rainfall missions fails to meet operational data needs for flood management, even when assuming a perfectly coordinated data product from all current rainfall-focused missions (i.e., the full portfolio). In the full portfolio, satellite-based rainfall data deficits vary across the globe and may preclude climate adaptation in locations vulnerable to increasing flood risks. Moreover, removing satellites that are currently beyond their design life (i.e., the reduced portfolio) dramatically increases data deficits globally and could cause entire high intensity flood events to be unobserved. Recovery from the reduced portfolio is possible with internationally coordinated replenishment of as few as 2 of the 4 satellite systems beyond their design life, yielding rainfall data coverages that outperform the current full portfolio (i.e., an optimized portfolio of eight satellites can outperform ten satellites). This work demonstrates the potential for internationally coordinated satellite replenishment and data services to substantially enhance the cost-effectiveness, sustainability and operational value of space-based rainfall observations in managing evolving flood risks. (letter)

  18. Partially Observable Markov Decision Process-Based Transmission Policy over Ka-Band Channels for Space Information Networks

    Directory of Open Access Journals (Sweden)

    Jian Jiao

    2017-09-01

    Full Text Available The Ka-band and higher Q/V band channels can provide an appealing capacity for the future deep-space communications and Space Information Networks (SIN, which are viewed as a primary solution to satisfy the increasing demands for high data rate services. However, Ka-band channel is much more sensitive to the weather conditions than the conventional communication channels. Moreover, due to the huge distance and long propagation delay in SINs, the transmitter can only obtain delayed Channel State Information (CSI from feedback. In this paper, the noise temperature of time-varying rain attenuation at Ka-band channels is modeled to a two-state Gilbert–Elliot channel, to capture the channel capacity that randomly ranging from good to bad state. An optimal transmission scheme based on Partially Observable Markov Decision Processes (POMDP is proposed, and the key thresholds for selecting the optimal transmission method in the SIN communications are derived. Simulation results show that our proposed scheme can effectively improve the throughput.

  19. Comments on Current Space Systems Observing the Climate

    Science.gov (United States)

    Fisk, L. A.

    2016-07-01

    The Global Climate Observing System (GCOS), which was established in 1992, has been effective in specifying the observations needed for climate studies, and advocating that these observations be made. As a result, there are essential climate variables being observed, particularly from space, and these have formed the basis for our ever-improving models of how the Earth system functions and the human impact on it. We cannot conclude, however, that the current observing system in space is adequate. Climate change is accelerating, and we need to ensure that our observations capture, with completeness and with proper resolution and cadence, the most important changes. Perhaps of most significance, we need to use observations from space to guide the mitigation and adaptation strategies on which at last our civilization seems prepared to embark. And we need to use our observations to educate particularly policy makers on the reality of climate change, so that none deny the need to act. COSPAR is determined to play its part in highlighting the need to strengthen the climate observing system and notably its research component. This is being accomplished through events like the present roundtable, through the work of its Scientific Commission A, its Task Group on GEO (where COSPAR is serving as a member of its Program Board), and by promoting among space agencies and policy-makers the recently released scientific roadmap on Integrated Earth System Science for the period 2016-2025.

  20. Analyzing the capability of a radio telescope in a bistatic space debris observation system

    International Nuclear Information System (INIS)

    Zhao Zhe; Zhao You; Gao Peng-Qi

    2013-01-01

    A bistatic space debris observation system using a radio telescope as the receiving part is introduced. The detection capability of the system at different working frequencies is analyzed based on real instruments. The detection range of targets with a fixed radar cross section and the detection ability of small space debris at a fixed range are discussed. The simulations of this particular observation system at different transmitting powers are also implemented and the detection capability is discussed. The simulated results approximately match the actual experiments. The analysis in this paper provides a theoretical basis for developing a space debris observation system that can be built in China

  1. Ballistic Target PHD Filter Based on Infrared Focal Plane Ambiguous Observation

    Directory of Open Access Journals (Sweden)

    Wei Zhao

    2017-01-01

    Full Text Available Space-based early warning system, the main detection means of which is passive detection based on focal plane, is an important part of ballistic missile defense system. The focal plane is mainly composed of CCD, and its size can reach the micron level, so the pixel is often regarded as point of no area in image postprocessing. The design of traditional tracking methods is based on this, and the observation based on the focal plane is modeled as the azimuth with random noise. However, this modeling is inaccurate. In the context of space-based detection, CCD cannot be simplified as a point, and its size should be considered. And the corresponding observation cannot be treated as azimuth with random noise. In this paper, the observation based on focal plane is modeled as Unambiguously Generated Ambiguous (UGA measurement. The PHD filter algorithm is redesigned and simplified. The simulation results show that the algorithm based on UGA measurement observation model has better tracking effect compared with that based on traditional observation model. This method provides technical support for more accurate target tracking for space-based early warning system.

  2. Remote observing with NASA's Deep Space Network

    Science.gov (United States)

    Kuiper, T. B. H.; Majid, W. A.; Martinez, S.; Garcia-Miro, C.; Rizzo, J. R.

    2012-09-01

    The Deep Space Network (DSN) communicates with spacecraft as far away as the boundary between the Solar System and the interstellar medium. To make this possible, large sensitive antennas at Canberra, Australia, Goldstone, California, and Madrid, Spain, provide for constant communication with interplanetary missions. We describe the procedures for radioastronomical observations using this network. Remote access to science monitor and control computers by authorized observers is provided by two-factor authentication through a gateway at the Jet Propulsion Laboratory (JPL) in Pasadena. To make such observations practical, we have devised schemes based on SSH tunnels and distributed computing. At the very minimum, one can use SSH tunnels and VNC (Virtual Network Computing, a remote desktop software suite) to control the science hosts within the DSN Flight Operations network. In this way we have controlled up to three telescopes simultaneously. However, X-window updates can be slow and there are issues involving incompatible screen sizes and multi-screen displays. Consequently, we are now developing SSH tunnel-based schemes in which instrument control and monitoring, and intense data processing, are done on-site by the remote DSN hosts while data manipulation and graphical display are done at the observer's host. We describe our approaches to various challenges, our experience with what worked well and lessons learned, and directions for future development.

  3. Application of Observing System Simulation Experiments (OSSEs) to determining science and user requirements for space-based missions

    Science.gov (United States)

    Atlas, R. M.

    2016-12-01

    Observing System Simulation Experiments (OSSEs) provide an effective method for evaluating the potential impact of proposed new observing systems, as well as for evaluating trade-offs in observing system design, and in developing and assessing improved methodology for assimilating new observations. As such, OSSEs can be an important tool for determining science and user requirements, and for incorporating these requirements into the planning for future missions. Detailed OSSEs have been conducted at NASA/ GSFC and NOAA/AOML in collaboration with Simpson Weather Associates and operational data assimilation centers over the last three decades. These OSSEs determined correctly the quantitative potential for several proposed satellite observing systems to improve weather analysis and prediction prior to their launch, evaluated trade-offs in orbits, coverage and accuracy for space-based wind lidars, and were used in the development of the methodology that led to the first beneficial impacts of satellite surface winds on numerical weather prediction. In this talk, the speaker will summarize the development of OSSE methodology, early and current applications of OSSEs and how OSSEs will evolve in order to enhance mission planning.

  4. Atmospheric Variability of CO2 impact on space observation Requirements

    Science.gov (United States)

    Swanson, A. L.; Sen, B.; Newhart, L.; Segal, G.

    2009-12-01

    If International governments are to reduce GHG levels by 80% by 2050, as recommended by most scientific bodies concerned with avoiding the most hazardous changes in climate, then massive investments in infrastructure and new technology will be required over the coming decades. Such an investment will be a huge commitment by governments and corporations, and while it will offer long-term dividends in lower energy costs, a healthier environment and averted additional global warming, the shear magnitude of upfront costs will drive a call for a monitoring and verification system. Such a system will be required to offer accountability to signatories of governing bodies, as well as, for the global public. Measuring the average global distribution of CO2 is straight forward, as exemplified by the long running station measurements managed by NOAA’s Global Monitoring Division that includes the longterm Keeling record. However, quantifying anthropogenic and natural source/sink distributions and atmospheric mixing have been much more difficult to constrain. And, yet, an accurate accounting of all anthropogenic source strengths is required for Global Treaty verification. The only way to accurately assess Global GHG emissions is to construct an integrated system of ground, air and space based observations with extensive chemical modeling capabilities. We look at the measurement requirements for the space based component of the solutions. To determine what space sensor performance requirements for ground resolution, coverage, and revisit, we have analyzed regional CO2 distributions and variability using NASA and NOAA aircraft flight campaigns. The results of our analysis are presented as variograms showing average spatial variability over several Northern Hemispheric regions. There are distinct regional differences with the starkest contrast between urban versus rural and Coastal Asia versus Coastal US. The results suggest specific consequences on what spatial and temporal

  5. Observing the Anthropocene from Space

    Science.gov (United States)

    Burrows, John

    The industrial revolution, which began in the UK in the late 18th century, has been fuelled by the use of cheap energy from fossil fuel combustion. It has facilitated a dramatic rise in both the human population, now above 7 Billion with 50% now living in urban agglomerations, and its standard of living. It is anticipated that by 2050 there will be of the order of 8.3 to 10 billion people, 75% living in cities. Anthropogenic activity has resulted in pollution from the local to the global scale changes in land use, the destruction of stratospheric ozone, the modification of biogeochemical cycling, acid deposition, impacted on ecosystems and ecosystem services, destruction of biodiversity and climate change. The impact of man has moved the earth from the Holocene to the new geological epoch of the Anthropocene. To improve our understanding of the earth atmosphere system and the accuracy of the prediction of its future changes, knowledge of the amounts and distributions of trace atmospheric constituents are essential -“One cannot manage what is not measured”. An integrated observing system, comprising ground and space based segments is required to improve our science and to provide an evidence base needed for environmental policymakers. Passive remote sensing measurements made of the up-welling radiation at the top of the atmosphere from instrumentation on space borne platforms provide a unique opportunity to retrieve globally atmospheric composition. This presentation describes results from the SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY on ESA Envsiat 2002 to 2012) and its spin offs GOME (Global Ozone Monitoring Experiment ESA ERS-2 1995 to 2011) and GOME-2 (ESA/EUMETSAT Metop series). The potential of the SCIAMACHY successors Sentinel 5, CarbonSat, and SCIA-ISS will also be addressed.

  6. OGLE-2017-BLG-0329L: A Microlensing Binary Characterized with Dramatically Enhanced Precision Using Data from Space-based Observations

    Science.gov (United States)

    Han, C.; Calchi Novati, S.; Udalski, A.; Lee, C.-U.; Gould, A.; Bozza, V.; Mróz, P.; Pietrukowicz, P.; Skowron, J.; Szymański, M. K.; Poleski, R.; Soszyński, I.; Kozłowski, S.; Ulaczyk, K.; Pawlak, M.; Rybicki, K.; Iwanek, P.; The OGLE Collaboration; Albrow, M. D.; Chung, S.-J.; Hwang, K.-H.; Jung, Y. K.; Ryu, Y.-H.; Shin, I.-G.; Shvartzvald, Y.; Yee, J. C.; Zang, W.; Zhu, W.; Cha, S.-M.; Kim, D.-J.; Kim, H.-W.; Kim, S.-L.; Lee, D.-J.; Lee, Y.; Park, B.-G.; Pogge, R. W.; Kim, W.-T.; The KMTNet Collaboration; Beichman, C.; Bryden, G.; Carey, S.; Gaudi, B. S.; Henderson, C. B.; The Spitzer Team; Dominik, M.; Helling, C.; Hundertmark, M.; Jørgensen, U. G.; Longa-Peña, P.; Lowry, S.; Sajadian, S.; Burgdorf, M. J.; Campbell-White, J.; Ciceri, S.; Evans, D. F.; Haikala, L. K.; Hinse, T. C.; Rahvar, S.; Rabus, M.; Snodgrass, C.; The MiNDSTEp Collaboration

    2018-06-01

    Mass measurements of gravitational microlenses require one to determine the microlens parallax π E, but precise π E measurement, in many cases, is hampered due to the subtlety of the microlens-parallax signal combined with the difficulty of distinguishing the signal from those induced by other higher-order effects. In this work, we present the analysis of the binary-lens event OGLE-2017-BLG-0329, for which π E is measured with a dramatically improved precision using additional data from space-based Spitzer observations. We find that while the parallax model based on the ground-based data cannot be distinguished from a zero-π E model at the 2σ level, the addition of the Spitzer data enables us to identify two classes of solutions, each composed of a pair of solutions according to the well-known ecliptic degeneracy. It is found that the space-based data reduce the measurement uncertainties of the north and east components of the microlens-parallax vector {{\\boldsymbol{π }}}{{E}} by factors ∼18 and ∼4, respectively. With the measured microlens parallax combined with the angular Einstein radius measured from the resolved caustic crossings, we find that the lens is composed of a binary with component masses of either (M 1, M 2) ∼ (1.1, 0.8) M ⊙ or ∼(0.4, 0.3) M ⊙ according to the two solution classes. The first solution is significantly favored but the second cannot be securely ruled out based on the microlensing data alone. However, the degeneracy can be resolved from adaptive optics observations taken ∼10 years after the event.

  7. Problem and Project Based Learning in Hybrid Spaces

    DEFF Research Database (Denmark)

    Ryberg, Thomas; Davidsen, Jacob; Hodgson, Vivien

    2016-01-01

    There is a need within networked learning to understand and conceptualise the interplay between digital and physical spaces or what we could term hybrid spaces. Therefore, we discuss a recent study of students from two different programmes who are engaged in long-term, group-based problem...... and project based learning. Based on interviews, workshops and observations of students’ actual group practices in open, shared and flexible spaces in Aalborg University (AAU), we identify and discuss how students incorporate networked and digital technologies into their group work and into the study places...... they create for themselves. We describe how in one of the programmes ‘nomadic’ groups of students used different technologies and spaces for ‘placemaking’. We then show how their experience and approach to collaborative work differs to that of the more static or ‘artisan’ groups of students in the other...

  8. First Space VLBI Observations and Images Using the VLBA and VSOP

    Science.gov (United States)

    Romney, J. D.; Benson, J. M.; Claussen, M. J.; Desai, K. M.; Flatters, C.; Mioduszewski, A. J.; Ulvestad, J. S.

    1997-12-01

    The National Radio Astronomy Observatory (NRAO) is a participant in the VSOP Space VLBI mission, an international collaboration led by Japan's Institute of Space and Astronautical Science. NRAO has committed up to 30% of scheduled observing time on the Very Long Baseline Array (VLBA), and corresponding correlation resources, to Space VLBI observations. The NRAO Space VLBI Project, funded by NASA, has been working for several years to complete the necessary enhancements to the VLBA correlator and the AIPS image processing system. These developments were completed by the time of the successful launch of the VSOP mission's Halca spacecraft on 1997 February 12. As part of the in-orbit checkout phase, the first Space VLBI fringes from a VLBA observation were detected on 1997 June 12, and the VSOP mission's first images, in both the 1.6- and 5-GHz bands, were obtained shortly thereafter. In-orbit test observations continued through early September, with the first General Observing Time (GOT) scientific observations beginning in July. Through mid-October, a total of 20 Space VLBI observations, comprising 190 hours, had been completed at the VLBA correlator. This paper reviews the unique features of correlation and imaging of Space VLBI observations. These include, for correlation, the ephemeris for an orbiting VLBI ``station'' which is not fixed on the surface of the earth, and the requirement to close the loop on the phase-transfer process from a frequency standard on the ground to the spacecraft. Images from a number of early tests and scientific observations are presented. NRAO's user-support program, providing expert assistance in data analysis to Space VLBI observers, is also described.

  9. Earth Observation from Space - The Issue of Environmental Sustainability

    Science.gov (United States)

    Durrieu, Sylvie; Nelson, Ross F.

    2013-01-01

    Remote sensing scientists work under assumptions that should not be taken for granted and should, therefore, be challenged. These assumptions include the following: 1. Space, especially Low Earth Orbit (LEO), will always be available to governmental and commercial space entities that launch Earth remote sensing missions. 2. Space launches are benign with respect to environmental impacts. 3. Minimization of Type 1 error, which provides increased confidence in the experimental outcome, is the best way to assess the significance of environmental change. 4. Large-area remote sensing investigations, i.e. national, continental, global studies, are best done from space. 5. National space missions should trump international, cooperative space missions to ensure national control and distribution of the data products. At best, all of these points are arguable, and in some cases, they're wrong. Development of observational space systems that are compatible with sustainability principles should be a primary concern when Earth remote sensing space systems are envisioned, designed, and launched. The discussion is based on the hypothesis that reducing the environmental impacts of thedata acquisition step,which is at the very beginning of the information streamleading to decision and action, will enhance coherence in the information streamand strengthen the capacity of measurement processes to meet their stated functional goal, i.e. sustainable management of Earth resources. We suggest that unconventional points of view should be adopted and when appropriate, remedial measures considered that could help to reduce the environmental footprint of space remote sensing and of Earth observation and monitoring systems in general. This article discusses these five assumptions inthe contextof sustainablemanagementof Earth's resources. Takingeachassumptioninturn,we find the following: (1) Space debris may limit access to Low Earth Orbit over the next decades. (2) Relatively speaking, given

  10. Event-based Sensing for Space Situational Awareness

    Science.gov (United States)

    Cohen, G.; Afshar, S.; van Schaik, A.; Wabnitz, A.; Bessell, T.; Rutten, M.; Morreale, B.

    A revolutionary type of imaging device, known as a silicon retina or event-based sensor, has recently been developed and is gaining in popularity in the field of artificial vision systems. These devices are inspired by a biological retina and operate in a significantly different way to traditional CCD-based imaging sensors. While a CCD produces frames of pixel intensities, an event-based sensor produces a continuous stream of events, each of which is generated when a pixel detects a change in log light intensity. These pixels operate asynchronously and independently, producing an event-based output with high temporal resolution. There are also no fixed exposure times, allowing these devices to offer a very high dynamic range independently for each pixel. Additionally, these devices offer high-speed, low power operation and a sparse spatiotemporal output. As a consequence, the data from these sensors must be interpreted in a significantly different way to traditional imaging sensors and this paper explores the advantages this technology provides for space imaging. The applicability and capabilities of event-based sensors for SSA applications are demonstrated through telescope field trials. Trial results have confirmed that the devices are capable of observing resident space objects from LEO through to GEO orbital regimes. Significantly, observations of RSOs were made during both day-time and nighttime (terminator) conditions without modification to the camera or optics. The event based sensor’s ability to image stars and satellites during day-time hours offers a dramatic capability increase for terrestrial optical sensors. This paper shows the field testing and validation of two different architectures of event-based imaging sensors. An eventbased sensor’s asynchronous output has an intrinsically low data-rate. In addition to low-bandwidth communications requirements, the low weight, low-power and high-speed make them ideally suitable to meeting the demanding

  11. Some observations on a fuzzy metric space

    Energy Technology Data Exchange (ETDEWEB)

    Gregori, V.

    2017-07-01

    Let $(X,d)$ be a metric space. In this paper we provide some observations about the fuzzy metric space in the sense of Kramosil and Michalek $(Y,N,/wedge)$, where $Y$ is the set of non-negative real numbers $[0,/infty[$ and $N(x,y,t)=1$ if $d(x,y)/leq t$ and $N(x,y,t)=0$ if $d(x,y)/geq t$. (Author)

  12. Earth Observations from Space: The First 50 Years of Scientific Achievements

    Science.gov (United States)

    2008-01-01

    Observing Earth from space over the past 50 years has fundamentally transformed the way people view our home planet. The image of the "blue marble" is taken for granted now, but it was revolutionary when taken in 1972 by the crew on Apollo 17. Since then the capability to look at Earth from space has grown increasingly sophisticated and has evolved from simple photographs to quantitative measurements of Earth properties such as temperature, concentrations of atmospheric trace gases, and the exact elevation of land and ocean. Imaging Earth from space has resulted in major scientific accomplishments; these observations have led to new discoveries, transformed the Earth sciences, opened new avenues of research, and provided important societal benefits by improving the predictability of Earth system processes. This report highlights the scientific achievements made possible by the first five decades of Earth satellite observations by space-faring nations. It follows on a recent report from the National Research Council (NRC) entitled Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond, also referred to as the "decadal survey." Recognizing the increasing need for space observations, the decadal survey identifies future directions and priorities for Earth observations from space. This companion report was requested by the National Aeronautics and Space Administration (NASA) to highlight, through selected examples, important past contributions of Earth observations from space to our current understanding of the planet.

  13. Problem and Project Based Learning in Hybrid Spaces:Nomads and Artisans

    OpenAIRE

    Ryberg, Thomas; Davidsen, Jacob; Hodgson, Vivien

    2016-01-01

    There is a need within networked learning to understand and conceptualise the interplay between digital and physical spaces or what we could term hybrid spaces. Therefore, we discuss a recent study of students from two different programmes who are engaged in long-term, group-based problem and project based learning. Based on interviews, workshops and observations of students’ actual group practices in open, shared and flexible spaces in Aalborg University (AAU), we identify and discuss how st...

  14. Space Science Cloud: a Virtual Space Science Research Platform Based on Cloud Model

    Science.gov (United States)

    Hu, Xiaoyan; Tong, Jizhou; Zou, Ziming

    Through independent and co-operational science missions, Strategic Pioneer Program (SPP) on Space Science, the new initiative of space science program in China which was approved by CAS and implemented by National Space Science Center (NSSC), dedicates to seek new discoveries and new breakthroughs in space science, thus deepen the understanding of universe and planet earth. In the framework of this program, in order to support the operations of space science missions and satisfy the demand of related research activities for e-Science, NSSC is developing a virtual space science research platform based on cloud model, namely the Space Science Cloud (SSC). In order to support mission demonstration, SSC integrates interactive satellite orbit design tool, satellite structure and payloads layout design tool, payload observation coverage analysis tool, etc., to help scientists analyze and verify space science mission designs. Another important function of SSC is supporting the mission operations, which runs through the space satellite data pipelines. Mission operators can acquire and process observation data, then distribute the data products to other systems or issue the data and archives with the services of SSC. In addition, SSC provides useful data, tools and models for space researchers. Several databases in the field of space science are integrated and an efficient retrieve system is developing. Common tools for data visualization, deep processing (e.g., smoothing and filtering tools), analysis (e.g., FFT analysis tool and minimum variance analysis tool) and mining (e.g., proton event correlation analysis tool) are also integrated to help the researchers to better utilize the data. The space weather models on SSC include magnetic storm forecast model, multi-station middle and upper atmospheric climate model, solar energetic particle propagation model and so on. All the services above-mentioned are based on the e-Science infrastructures of CAS e.g. cloud storage and

  15. Observations of the Earth's magnetic field from the Space Station: Measurement at high and extremely low altitude using Space Station-controlled free-flyers

    Science.gov (United States)

    Webster, W., Jr.; Frawley, J. J.; Stefanik, M.

    1984-01-01

    Simulation studies established that the main (core), crustal and electrojet components of the Earth's magnetic field can be observed with greater resolution or over a longer time-base than is presently possible by using the capabilities provided by the space station. Two systems are studied. The first, a large lifetime, magnetic monitor would observe the main field and its time variation. The second, a remotely-piloted, magnetic probe would observe the crustal field at low altitude and the electrojet field in situ. The system design and the scientific performance of these systems is assessed. The advantages of the space station are reviewed.

  16. State of Art in space weather observational activities and data management in Europe

    Science.gov (United States)

    Stanislawska, Iwona

    One of the primary scientific and technical goals of space weather is to produce data in order to investigate the Sun impact on the Earth and its environment. Studies based on data mining philosophy yield increase the knowledge of space weather physical properties, modelling capabilities and gain applications of various procedures in space weather monitoring and forecasting. Exchanging tailored individually and/or jointly data between different entities, storing of the databases and making data accessible for the users is the most important task undertaken by investigators. National activities spread over Europe is currently consolidated pursuant to the terms of effectiveness and individual contributions embedded in joint integrated efforts. The role of COST 724 Action in animation of such a movement is essential. The paper focuses on the analysis of the European availability in the Internet near-real time and historical collections of the European ground based and satellite observations, operational indices and parameters. A detailed description of data delivered is included. The structure of the content is supplied according to the following selection: (1) observations, raw and/or corrected, updated data, (2) resolution, availability of real-time and historical data, (3) products, as the results of models and theory including (a) maps, forecasts and alerts, (b) resolution, availability of real-time and historical data, (4) platforms to deliver data. Characterization of the networking of stations, observatories and space related monitoring systems of data collections is integrated part of the paper. According to these provisions operational systems developed for these purposes is presented and analysed. It concerns measurements, observations and parameters from the theory and models referred to local, regional collections, European and worldwide networks. Techniques used by these organizations to generate the digital content are identified. As the reference pan

  17. Comparing observer models and feature selection methods for a task-based statistical assessment of digital breast tomsynthesis in reconstruction space

    Science.gov (United States)

    Park, Subok; Zhang, George Z.; Zeng, Rongping; Myers, Kyle J.

    2014-03-01

    A task-based assessment of image quality1 for digital breast tomosynthesis (DBT) can be done in either the projected or reconstructed data space. As the choice of observer models and feature selection methods can vary depending on the type of task and data statistics, we previously investigated the performance of two channelized- Hotelling observer models in conjunction with 2D Laguerre-Gauss (LG) and two implementations of partial least squares (PLS) channels along with that of the Hotelling observer in binary detection tasks involving DBT projections.2, 3 The difference in these observers lies in how the spatial correlation in DBT angular projections is incorporated in the observer's strategy to perform the given task. In the current work, we extend our method to the reconstructed data space of DBT. We investigate how various model observers including the aforementioned compare for performing the binary detection of a spherical signal embedded in structured breast phantoms with the use of DBT slices reconstructed via filtered back projection. We explore how well the model observers incorporate the spatial correlation between different numbers of reconstructed DBT slices while varying the number of projections. For this, relatively small and large scan angles (24° and 96°) are used for comparison. Our results indicate that 1) given a particular scan angle, the number of projections needed to achieve the best performance for each observer is similar across all observer/channel combinations, i.e., Np = 25 for scan angle 96° and Np = 13 for scan angle 24°, and 2) given these sufficient numbers of projections, the number of slices for each observer to achieve the best performance differs depending on the channel/observer types, which is more pronounced in the narrow scan angle case.

  18. Awareness-based game-theoretic space resource management

    Science.gov (United States)

    Chen, Genshe; Chen, Huimin; Pham, Khanh; Blasch, Erik; Cruz, Jose B., Jr.

    2009-05-01

    Over recent decades, the space environment becomes more complex with a significant increase in space debris and a greater density of spacecraft, which poses great difficulties to efficient and reliable space operations. In this paper we present a Hierarchical Sensor Management (HSM) method to space operations by (a) accommodating awareness modeling and updating and (b) collaborative search and tracking space objects. The basic approach is described as follows. Firstly, partition the relevant region of interest into district cells. Second, initialize and model the dynamics of each cell with awareness and object covariance according to prior information. Secondly, explicitly assign sensing resources to objects with user specified requirements. Note that when an object has intelligent response to the sensing event, the sensor assigned to observe an intelligent object may switch from time-to-time between a strong, active signal mode and a passive mode to maximize the total amount of information to be obtained over a multi-step time horizon and avoid risks. Thirdly, if all explicitly specified requirements are satisfied and there are still more sensing resources available, we assign the additional sensing resources to objects without explicitly specified requirements via an information based approach. Finally, sensor scheduling is applied to each sensor-object or sensor-cell pair according to the object type. We demonstrate our method with realistic space resources management scenario using NASA's General Mission Analysis Tool (GMAT) for space object search and track with multiple space borne observers.

  19. Space Weather Monitoring for ISS Space Environments Engineering and Crew Auroral Observations

    Science.gov (United States)

    Minow, Joseph I.; Pettit, Donald R.; Hartman, William A.

    2012-01-01

    The awareness of potentially significant impacts of space weather on spaceand ground ]based technological systems has generated a strong desire in many sectors of government and industry to effectively transform knowledge and understanding of the variable space environment into useful tools and applications for use by those entities responsible for systems that may be vulnerable to space weather impacts. Essentially, effectively transitioning science knowledge to useful applications relevant to space weather has become important. This talk will present proven methodologies that have been demonstrated to be effective, and how in the current environment those can be applied to space weather transition efforts.

  20. Observing Tropospheric Ozone From Space

    Science.gov (United States)

    Fishman, Jack

    2000-01-01

    The importance of tropospheric ozone embraces a spectrum of relevant scientific issues ranging from local environmental concerns, such as damage to the biosphere and human health, to those that impact global change questions, Such is climate warming. From an observational perspective, the challenge is to determine the tropospheric ozone global distribution. Because its lifetime is short compared with other important greenhouse gases that have been monitored over the past several decades, the distribution of tropospheric ozone cannot be inferred from a relatively small set of monitoring stations. Therefore, the best way to obtain a true global picture is from the use of space-based instrumentation where important spatial gradients over vast ocean expanses and other uninhabited areas can be properly characterized. In this paper, the development of the capability to measure tropospheric ozone from space over the past 15 years is summarized. Research in the late 1980s successfully led to the determination of the climatology of tropospheric ozone as a function of season; more recently, the methodology has improved to the extent where regional air pollution episodes can be characterized. The most recent modifications now provide quasi-global (50 N) to 50 S) maps on a daily basis. Such a data set would allow for the study of long-range (intercontinental) transport of air pollution and the quantification of how regional emissions feed into the global tropospheric ozone budget. Future measurement capabilities within this decade promise to offer the ability to provide Concurrent maps of the precursors to the in situ formation of tropospheric ozone from which the scientific community will gain unprecedented insight into the processes that control global tropospheric chemistry

  1. Space plasma observations - observations of solar-terrestrial environment. Space Weather Forecast

    International Nuclear Information System (INIS)

    Sagawa, Eiichi; Akioka, Maki

    1996-01-01

    The space environment becomes more important than ever before because of the expansion in the utilization of near-earth space and the increase in the vulnerability of large scale systems on the ground such as electrical power grids. The concept of the Space Weather Forecast program emerged from the accumulation of understanding on basic physical processes and from our activities as one of the regional warning centers of the international network of space environment services. (author)

  2. Cambridge observations at 38-115 MHz and their implications for space astronomy

    International Nuclear Information System (INIS)

    Saunders, R.

    1987-01-01

    The design and performance of the Cambridge LF telescopes are reviewed. Consideration is given to the 151-MHz 6C telescope, the 38-MHz and 151-MHz LF synthesis telescopes, 81.5-MHz interplanetary scintillation observations with the 3.6-hectare array, long-baseline interferometry at 81.5 MHz, and the use of the Jodrell Bank MERLIN for 151-MHz closure-phase observations of bright sources. The strict limitation on the field mappable at a given resolution in ground-based observations at these frequencies is pointed out, and some outstanding astronomical problems requiring 0.3-30-MHz space observations are listed. 7 references

  3. Relativity effects for space-based coherent lidar experiments

    Science.gov (United States)

    Gudimetla, V. S. Rao

    1996-01-01

    An effort was initiated last year in the Astrionics Laboratory at Marshall Space Flight Center to examine and incorporate, if necessary, the effects of relativity in the design of space-based lidar systems. A space-based lidar system, named AEOLUS, is under development at Marshall Space Flight Center and it will be used to accurately measure atmospheric wind profiles. Effects of relativity were also observed in the performance of space-based systems, for example in case of global positioning systems, and corrections were incorporated into the design of instruments. During the last summer, the effects of special relativity on the design of space-based lidar systems were studied in detail, by analyzing the problem of laser scattering off a fixed target when the source and a co-located receiver are moving on a spacecraft. Since the proposed lidar system uses a coherent detection system, errors even in the order of a few microradians must be corrected to achieve a good signal-to-noise ratio. Previous analysis assumed that the ground is flat and the spacecraft is moving parallel to the ground, and developed analytical expressions for the location, direction and Doppler shift of the returning radiation. Because of the assumptions used in that analysis, only special relativity effects were involved. In this report, that analysis is extended to include general relativity and calculate its effects on the design.

  4. Solar System Observations with the James Webb Space Telescope

    Science.gov (United States)

    Norwood, James; Hammel, Heidi; Milam, Stefanie; Stansberry, John; Lunine, Jonathan; Chanover, Nancy; Hines, Dean; Sonneborn, George; Tiscareno, Matthew; Brown, Michael; hide

    2016-01-01

    The James Webb Space Telescope (JWST) will enable a wealth of new scientific investigations in the near- and mid-infrared, with sensitivity and spatial/spectral resolution greatly surpassing its predecessors. In this paper, we focus upon Solar System science facilitated by JWST, discussing the most current information available concerning JWST instrument properties and observing techniques relevant to planetary science. We also present numerous example observing scenarios for a wide variety of Solar System targets to illustrate the potential of JWST science to the Solar System community. This paper updates and supersedes the Solar System white paper published by the JWST Project in 2010. It is based both on that paper and on a workshop held at the annual meeting of the Division for Planetary Sciences in Reno, NV, in 2012.

  5. Image processing improvement for optical observations of space debris with the TAROT telescopes

    Science.gov (United States)

    Thiebaut, C.; Theron, S.; Richard, P.; Blanchet, G.; Klotz, A.; Boër, M.

    2016-07-01

    CNES is involved in the Inter-Agency Space Debris Coordination Committee (IADC) and is observing space debris with two robotic ground based fully automated telescopes called TAROT and operated by the CNRS. An image processing algorithm devoted to debris detection in geostationary orbit is implemented in the standard pipeline. Nevertheless, this algorithm is unable to deal with debris tracking mode images, this mode being the preferred one for debris detectability. We present an algorithm improvement for this mode and give results in terms of false detection rate.

  6. Confined space ventilation by shipyard welders: observed use and effectiveness.

    Science.gov (United States)

    Pouzou, Jane G; Warner, Chris; Neitzel, Richard L; Croteau, Gerry A; Yost, Michael G; Seixas, Noah S

    2015-01-01

    Shipbuilding involves intensive welding activities within enclosed and confined spaces, and although ventilation is commonly used in the industry, its use and effectiveness has not been adequately documented. Workers engaged in welding in enclosed or confined spaces in two shipyards were observed for their use of ventilation and monitored for their exposure to particulate matter. The type of ventilation in use, its placement and face velocity, the movement of air within the space, and other ventilation-related parameters were recorded, along with task characteristics such as the type of welding, the welder's position, and the configuration of the space. Mechanical ventilation was present in about two-thirds of the 65 welding scenarios observed, with exhaust ventilation used predominantly in one shipyard and supply blowers predominantly in the other. Welders were observed working in apparent dead-spaces within the room in 53% of the cases, even where ventilation was in use. Respiratory protection was common in the two shipyards, observed in use in 77 and 100% of the cases. Welding method, the proximity of the welder's head to the fume, and air mixing were found to be significantly associated with the welder's exposure, while other characteristics of dilution ventilation did not produce appreciable differences in exposure level. These parameters associated with exposure reduction can be assessed subjectively and are thus good candidates for training on effective ventilation use during hot work in confined spaces. Ventilation used in confined space welding is often inadequate for controlling exposure to welding fume. © The Author 2014. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

  7. Optimal observables and phase-space ambiguities

    International Nuclear Information System (INIS)

    Nachtmann, O.; Nagel, F.

    2005-01-01

    Optimal observables are known to lead to minimal statistical errors on parameters for a given normalised event distribution of a physics reaction. Thereby all statistical correlations are taken into account. Therefore, on the one hand they are a useful tool to extract values on a set of parameters from measured data. On the other hand one can calculate the minimal constraints on these parameters achievable by any data-analysis method for the specific reaction. In case the final states can be reconstructed without ambiguities optimal observables have a particularly simple form. We give explicit formulae for the optimal observables for generic reactions in case of ambiguities in the reconstruction of the final state and for general parameterisation of the final-state phase space. (orig.)

  8. Space Debris and Observational Astronomy

    Science.gov (United States)

    Seitzer, Patrick

    2018-01-01

    Since the launch of Sputnik 1 in 1957, astronomers have faced an increasing number of artificial objects contaminating their images of the night sky. Currently almost 17000 objects larger than 10 cm are tracked and have current orbits in the public catalog. Active missions are only a small fraction of these objects. Most are inactive satellites, rocket bodies, and fragments of larger objects: all space debris. Several mega-constellations are planned which will increase this number by 20% or more in low Earth orbit (LEO). In terms of observational astronomy, this population of Earth orbiting objects has three implications: 1) the number of streaks and glints from spacecraft will only increase. There are some practical steps that can be taken to minimize the number of such streaks and glints in astronomical imaging data. 2) The risk to damage to orbiting astronomical telescopes will only increase, particularly those in LEO. 3) If you are working on a plan for an orbiting telescope project, then there are specific steps that must be taken to minimize space debris generation during the mission lifetime, and actions to safely dispose of the spacecraft at end of mission to prevent it from becoming space debris and a risk to other missions. These steps may involve sacrifices to mission performance and lifetime, but are essential in today's orbital environment.

  9. Research on Optimal Observation Scale for Damaged Buildings after Earthquake Based on Optimal Feature Space

    Science.gov (United States)

    Chen, J.; Chen, W.; Dou, A.; Li, W.; Sun, Y.

    2018-04-01

    A new information extraction method of damaged buildings rooted in optimal feature space is put forward on the basis of the traditional object-oriented method. In this new method, ESP (estimate of scale parameter) tool is used to optimize the segmentation of image. Then the distance matrix and minimum separation distance of all kinds of surface features are calculated through sample selection to find the optimal feature space, which is finally applied to extract the image of damaged buildings after earthquake. The overall extraction accuracy reaches 83.1 %, the kappa coefficient 0.813. The new information extraction method greatly improves the extraction accuracy and efficiency, compared with the traditional object-oriented method, and owns a good promotional value in the information extraction of damaged buildings. In addition, the new method can be used for the information extraction of different-resolution images of damaged buildings after earthquake, then to seek the optimal observation scale of damaged buildings through accuracy evaluation. It is supposed that the optimal observation scale of damaged buildings is between 1 m and 1.2 m, which provides a reference for future information extraction of damaged buildings.

  10. Observing Geohazards from Space

    Directory of Open Access Journals (Sweden)

    Francesca Cigna

    2018-02-01

    Full Text Available With a wide spectrum of imaging capabilities—from optical to radar sensors, low to very high resolution, continental to local scale, single-image to multi-temporal approaches, yearly to sub-daily acquisition repeat cycles—Earth Observation (EO offers several opportunities for the geoscience community to map and monitor natural and human-induced Earth hazards from space. The Special Issue “Observing Geohazards from Space” of Geosciences gathers 12 research articles on the development, validation, and implementation of satellite EO data, processing methods, and applications for mapping and monitoring of geohazards such as slow moving landslides, ground subsidence and uplift, and active and abandoned mining-induced ground movements. Papers published in this Special Issue provide novel case studies demonstrating how EO and remote sensing data can be used to detect and delineate land instability and geological hazards in different environmental contexts and using a range of spatial resolutions and image processing methods. Remote sensing datasets used in the Special Issue papers encompass satellite imagery from the ERS-1/2, ENVISAT, RADARSAT-1/2, and Sentinel-1 C-band, TerraSAR-X and COSMO-SkyMed X-band, and ALOS L-band SAR missions; Landsat 7, SPOT-5, WorldView-2/3, and Sentinel-2 multi-spectral data; UAV-derived RGB and near infrared aerial photographs; LiDAR surveying; and GNSS positioning data. Techniques that are showcased include, but are not limited to, differential Interferometric SAR (InSAR and its advanced approaches such as Persistent Scatterers (PS and Small Baseline Subset (SBAS methods to estimate ground deformation, Object-Based Image Analysis (OBIA to identify landslides in high resolution multi-spectral data, UAV and airborne photogrammetry, Structure-from-Motion (SfM for digital elevation model generation, aerial photo-interpretation, feature extraction, and time series analysis. Case studies presented in the papers focus on

  11. Observation of an Aligned Gas - Solid "Eutectic" during Controlled Directional Solidification Aboard the International Space Station - Comparison with Ground-based Studies

    Science.gov (United States)

    Grugel, R. N.; Anilkumar, A.

    2005-01-01

    Direct observation of the controlled melting and solidification of succinonitrile was conducted in the glovebox facility of the International Space Station (ISS). The experimental samples were prepared on ground by filling glass tubes, 1 cm ID and approximately 30 cm in length, with pure succinonitrile (SCN) in an atmosphere of nitrogen at 450 millibar pressure for eventual processing in the Pore Formation and Mobility Investigation (PFMI) apparatus in the glovebox facility (GBX) on board the ISS. Real time visualization during controlled directional melt back of the sample showed nitrogen bubbles emerging from the interface and moving through the liquid up the imposed temperature gradient. Over a period of time these bubbles disappear by dissolving into the melt. Translation is stopped after melting back of about 9 cm of the sample, with an equilibrium solid-liquid interface established. During controlled re-solidification, aligned tubes of gas were seen growing perpendicular to the planar solid/liquid interface, inferring that the nitrogen previously dissolved into the liquid SCN was now coming out at the solid/liquid interface and forming the little studied liquid = solid + gas eutectic-type reaction. The observed structure is evaluated in terms of spacing dimensions, interface undercooling, and mechanisms for spacing adjustments. Finally, the significance of processing in a microgravity environment is ascertained in view of ground-based results.

  12. A new space technology for ocean observation: the SMOS mission

    Directory of Open Access Journals (Sweden)

    Jordi Font

    2012-09-01

    Full Text Available Capability for sea surface salinity observation was an important gap in ocean remote sensing in the last few decades of the 20th century. New technological developments during the 1990s at the European Space Agency led to the proposal of SMOS (Soil Moisture and Ocean Salinity, an Earth explorer opportunity mission based on the use of a microwave interferometric radiometer, MIRAS (Microwave Imaging Radiometer with Aperture Synthesis. SMOS, the first satellite ever addressing the observation of ocean salinity from space, was successfully launched in November 2009. The determination of salinity from the MIRAS radiometric measurements at 1.4 GHz is a complex procedure that requires high performance from the instrument and accurate modelling of several physical processes that impact on the microwave emission of the ocean’s surface. This paper introduces SMOS in the ocean remote sensing context, and summarizes the MIRAS principles of operation and the SMOS salinity retrieval approach. It describes the Spanish SMOS high-level data processing centre (CP34 and the SMOS Barcelona Expert Centre on Radiometric Calibration and Ocean Salinity (SMOS-BEC, and presents a preliminary validation of global sea surface salinity maps operationally produced by CP34.

  13. Batman flies: a compact spectro-imager for space observation

    Science.gov (United States)

    Zamkotsian, Frederic; Ilbert, Olivier; Zoubian, Julien; Delsanti, Audrey; Boissier, Samuel; Lancon, Ariane

    2017-11-01

    Multi-object spectroscopy (MOS) is a key technique for large field of view surveys. MOEMS programmable slit masks could be next-generation devices for selecting objects in future infrared astronomical instrumentation for space telescopes. MOS is used extensively to investigate astronomical objects by optimizing the Signal-to-Noise Ratio (SNR): high precision spectra are obtained and the problem of spectral confusion and background level occurring in slitless spectroscopy is cancelled. Fainter limiting fluxes are reached and the scientific return is maximized both in cosmology and in legacy science. Major telescopes around the world are equipped with MOS in order to simultaneously record several hundred spectra in a single observation run. Next generation MOS for space like the Near Infrared Multi-Object Spectrograph (NIRSpec) for the James Webb Space Telescope (JWST) require a programmable multi-slit mask. Conventional masks or complex fiber-optics-based mechanisms are not attractive for space. The programmable multi-slit mask requires remote control of the multislit configuration in real time. During the early-phase studies of the European Space Agency (ESA) EUCLID mission, a MOS instrument based on a MOEMS device has been assessed. Due to complexity and cost reasons, slitless spectroscopy was chosen for EUCLID, despite a much higher efficiency with slit spectroscopy. A promising possible solution is the use of MOEMS devices such as micromirror arrays (MMA) [1,2,3] or micro-shutter arrays (MSA) [4]. MMAs are designed for generating reflecting slits, while MSAs generate transmissive slits. In Europe an effort is currently under way to develop single-crystalline silicon micromirror arrays for future generation infrared multi-object spectroscopy (collaboration LAM / EPFL-CSEM) [5,6]. By placing the programmable slit mask in the focal plane of the telescope, the light from selected objects is directed toward the spectrograph, while the light from other objects and

  14. Lightning Observations from the International Space Station (ISS) for Science Research and Operational Applications

    Science.gov (United States)

    Blakeslee, R. J.; Christian, H. J.; Mach, D. M.; Buechler, D. E.; Koshak, W. J.; Walker, T. D.; Bateman, M.; Stewart, M. F.; O'Brien, S.; Wilson, T.; hide

    2015-01-01

    There exist several core science applications of LIS lightning observations, that range from weather and climate to atmospheric chemistry and lightning physics due to strong quantitative connections that can be made between lightning and other geophysical processes of interest. The space-base vantage point, such as provided by ISS LIS, still remains an ideal location to obtain total lightning observations on a global basis.

  15. Integrating Satellite, Radar and Surface Observation with Time and Space Matching

    Science.gov (United States)

    Ho, Y.; Weber, J.

    2015-12-01

    The Integrated Data Viewer (IDV) from Unidata is a Java™-based software framework for analyzing and visualizing geoscience data. It brings together the ability to display and work with satellite imagery, gridded data, surface observations, balloon soundings, NWS WSR-88D Level II and Level III RADAR data, and NOAA National Profiler Network data, all within a unified interface. Applying time and space matching on the satellite, radar and surface observation datasets will automatically synchronize the display from different data sources and spatially subset to match the display area in the view window. These features allow the IDV users to effectively integrate these observations and provide 3 dimensional views of the weather system to better understand the underlying dynamics and physics of weather phenomena.

  16. Perspectives for Distributed Observations of Near-Earth Space Using a Russian-Cuban Observatory

    Science.gov (United States)

    Bisikalo, D. V.; Savanov, I. S.; Naroenkov, S. A.; Nalivkin, M. A.; Shugarov, A. S.; Bakhtigaraev, N. S.; Levkina, P. A.; Ibragimov, M. A.; Kil'pio, E. Yu.; Sachkov, M. E.; Kartashova, A. P.; Fateeva, A. M.; Uratsuka, Marta R. Rodriguez; Estrada, Ramses Zaldivar; Diaz, Antonio Alonsa; Rodríguez, Omar Pons; Figuera, Fidel Hernandes; Garcia, Maritza Garcia

    2018-06-01

    The creation of a specialized network of large, wide-angle telescopes for distributed observations of near-Earth space using a Russian-Cuban Observatory is considered. An extremely important goal of routine monitoring of near-Earth and near-Sun space is warding off threats with both natural and technogenic origins. Natural threats are associated with asteroids or comets, and technogenic threats with man-made debris in near-Earth space. A modern network of ground-based optical instruments designed to ward off such threats must: (a) have a global and, if possible, uniform geographic distribution, (b) be suitable for wide-angle, high-accuracy precision survey observations, and (c) be created and operated within a single network-oriented framework. Experience at the Institute of Astronomy on the development of one-meter-class wide-angle telescopes and elements of a super-wide-angle telescope cluster is applied to determine preferences for the composition of each node of such a network. The efficiency of distributed observations in attaining maximally accurate predictions of the motions of potentially dangerous celestial bodies as they approach the Earth and in observations of space debris and man-made satellites is estimated. The first estimates of astroclimatic conditions at the proposed site of the future Russian-Cuban Observatory in the mountains of the Sierra del Rosario Biosphere Reserve are obtained. Special attention is given to the possible use of the network to carry out a wide range of astrophysical studies, including optical support for the localization of gravitational waves and other transient events.

  17. High Precision Optical Observations of Space Debris in the Geo Ring from Venezuela

    Science.gov (United States)

    Lacruz, E.; Abad, C.; Downes, J. J.; Casanova, D.; Tresaco, E.

    2018-01-01

    We present preliminary results to demonstrate that our method for detection and location of Space Debris (SD) in the geostationary Earth orbit (GEO) ring, based on observations at the OAN of Venezuela is of high astrometric precision. A detailed explanation of the method, its validation and first results is available in (Lacruz et al. 2017).

  18. Observer-dependent quantum vacua in curved space. II

    International Nuclear Information System (INIS)

    Castagnino, M.A.; Sztrajman, J.B.

    1989-01-01

    An observer-dependent Hamiltonian is introduced in order to describe massless spin-1 particles in curved space-times. The vacuum state is defined by means of Hamiltonian diagonalization and minimization, which turns out to be equivalent criteria. This method works in an arbitrary geometry, although a condition on the fluid of observers is required. Computations give the vacua commonly accepted in the literature

  19. An observational study of defensible space in the neighbourhood park

    Science.gov (United States)

    Marzukhi, M. A.; Afiq, M. A.; Zaki, S. Ahmad; Ling, O. H. L.

    2018-02-01

    The planning of neighborhood park is important to provide space for interaction, leisure, and recreation among residents in any neighbourhood area. However, on an almost daily basis, newspapers report inappropriate incidents such as snatch theft, robbery and street attack that occurred in the neighborhood park. These cases reflect the significance of physical planning and design of neighborhood park that directly affect the safety and comfort of the users. Thus, this study attempts to engage with the defensible space concept in ensuring the security elements be applied in the planning of the recreational area. This study adopts a qualitative method form of research that is retrofitted to an observational study. The observational study is significant for revealing the condition of a neighbourhood park in the ‘real-world,’ in which direct observation is conducted on Taman Tasik Puchong Perdana. The observer focused on four elements or variables of defensible space concept including the provision of facilities in the neighborhood park, territoriality, surveillance, image and milieu. The findings revealed that the planning of Taman Tasik Puchong Perdana does not deliberate the defensible space elements, which may contribute to the crime activities in the park. In these circumstances, the planning of neighbourhood park needs to include proposals for the implementation of defensible space in response to the challenges underpinned by crime problems. Besides, the awareness among the residents needs to be emphasized with the support from local authorities and other organizations to manage and sustain the safety environment in the neighborhood park.

  20. First observations of iodine oxide from space

    Science.gov (United States)

    Saiz-Lopez, Alfonso; Chance, Kelly; Liu, Xiong; Kurosu, Thomas P.; Sander, Stanley P.

    2007-06-01

    We present retrievals of IO total columns from the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) satellite instrument. We analyze data for October 2005 in the polar regions to demonstrate for the first time the capability to measure IO column abundances from space. During the period of analysis (i.e. Southern Hemisphere springtime), enhanced IO vertical columns over 3 × 1013 molecules cm-2 are observed around coastal Antarctica; by contrast during that time in the Artic region IO is consistently below the calculated instrumental detection limit for individual radiance spectra (2-4 × 1012 molecules cm-2 for slant columns). The levels reported here are in reasonably good agreement with previous ground-based measurements at coastal Antarctica. These results also demonstrate that IO is widespread over sea-ice covered areas in the Southern Ocean. The occurrence of elevated IO and its hitherto unrecognized spatial distribution suggest an efficient iodine activation mechanism at a synoptic scale over coastal Antarctica.

  1. Observation of the Earth system from space

    CERN Document Server

    Flury, Jakob; Reigber, Christoph; Rothacher, Markus; Boedecker, Gerd

    2006-01-01

    In the recent years, space-based observation methods have led to a subst- tially improved understanding of Earth system. Geodesy and geophysics are contributing to this development by measuring the temporal and spatial va- ations of the Earth's shape, gravity ?eld, and magnetic ?eld, as well as at- sphere density. In the frame of the GermanR&D programmeGEOTECHNO- LOGIEN,researchprojectshavebeen launchedin2002relatedto the satellite missions CHAMP, GRACE and ESA's planned mission GOCE, to comp- mentary terrestrial and airborne sensor systems and to consistent and stable high-precision global reference systems for satellite and other techniques. In the initial 3-year phase of the research programme (2002-2004), new gravity ?eld models have been computed from CHAMP and GRACE data which outperform previous models in accuracy by up to two orders of m- nitude for the long and medium wavelengths. A special highlight is the - termination of seasonal gravity variations caused by changes in continental water masses...

  2. Speech-based recognition of self-reported and observed emotion in a dimensional space

    NARCIS (Netherlands)

    Truong, Khiet Phuong; van Leeuwen, David A.; de Jong, Franciska M.G.

    2012-01-01

    The differences between self-reported and observed emotion have only marginally been investigated in the context of speech-based automatic emotion recognition. We address this issue by comparing self-reported emotion ratings to observed emotion ratings and look at how differences between these two

  3. Hubble Space Telescope Observations of cD Galaxies and Their Globular Cluster Systems

    Science.gov (United States)

    Jordán, Andrés; Côté, Patrick; West, Michael J.; Marzke, Ronald O.; Minniti, Dante; Rejkuba, Marina

    2004-01-01

    We have used WFPC2 on the Hubble Space Telescope (HST) to obtain F450W and F814W images of four cD galaxies (NGC 541 in Abell 194, NGC 2832 in Abell 779, NGC 4839 in Abell 1656, and NGC 7768 in Abell 2666) in the range 5400 km s-1cluster (GC) systems reveals no anomalies in terms of specific frequencies, metallicity gradients, average metallicities, or the metallicity offset between the globular clusters and the host galaxy. We show that the latter offset appears roughly constant at Δ[Fe/H]~0.8 dex for early-type galaxies spanning a luminosity range of roughly 4 orders of magnitude. We combine the globular cluster metallicity distributions with an empirical technique described in a series of earlier papers to investigate the form of the protogalactic mass spectrum in these cD galaxies. We find that the observed GC metallicity distributions are consistent with those expected if cD galaxies form through the cannibalism of numerous galaxies and protogalactic fragments that formed their stars and globular clusters before capture and disruption. However, the properties of their GC systems suggest that dynamical friction is not the primary mechanism by which these galaxies are assembled. We argue that cD's instead form rapidly, via hierarchical merging, prior to cluster virialization. Based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555 Based in part on observations obtained at the European Southern Observatory, for VLT program 68.D-0130(A).

  4. Hubble space telescope and ground-based observations of the type Iax supernovae SN 2005hk and SN 2008A

    Energy Technology Data Exchange (ETDEWEB)

    McCully, Curtis; Jha, Saurabh W. [Department of Physics and Astronomy, Rutgers, the State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Foley, Ryan J. [Astronomy Department, University of Illinois at Urbana-Champaign, 1002 West Green Street, Urbana, IL 61801 (United States); Chornock, Ryan [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Holtzman, Jon A. [Department of Astronomy, MSC 4500, New Mexico State University, P.O. Box 30001, Las Cruces, NM 88003 (United States); Balam, David D. [Dominion Astrophysical Observatory, Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Branch, David [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States); Filippenko, Alexei V.; Ganeshalingam, Mohan; Li, Weidong [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Frieman, Joshua [Kavli Institute for Cosmological Physics and Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Fynbo, Johan; Leloudas, Giorgos [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen Ø (Denmark); Galbany, Lluis [Institut de Física d' Altes Energies, Universitat Autònoma de Barcelona, E-08193 Bellaterra (Barcelona) (Spain); Garnavich, Peter M. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Graham, Melissa L. [Las Cumbres Observatory Global Telescope Network, Goleta, CA 93117 (United States); Hsiao, Eric Y. [Carnegie Observatories, Las Campanas Observatory, Colina El Pino, Casilla 601 (Chile); Leonard, Douglas C., E-mail: cmccully@physics.rutgers.edu [Department of Astronomy, San Diego State University, San Diego, CA 92182 (United States); and others

    2014-05-10

    We present Hubble Space Telescope (HST) and ground-based optical and near-infrared observations of SN 2005hk and SN 2008A, typical members of the Type Iax class of supernovae (SNe). Here we focus on late-time observations, where these objects deviate most dramatically from all other SN types. Instead of the dominant nebular emission lines that are observed in other SNe at late phases, spectra of SNe 2005hk and 2008A show lines of Fe II, Ca II, and Fe I more than a year past maximum light, along with narrow [Fe II] and [Ca II] emission. We use spectral features to constrain the temperature and density of the ejecta, and find high densities at late times, with n{sub e} ≳ 10{sup 9} cm{sup –3}. Such high densities should yield enhanced cooling of the ejecta, making these objects good candidates to observe the expected 'infrared catastrophe', a generic feature of SN Ia models. However, our HST photometry of SN 2008A does not match the predictions of an infrared catastrophe. Moreover, our HST observations rule out a 'complete deflagration' that fully disrupts the white dwarf for these peculiar SNe, showing no evidence for unburned material at late times. Deflagration explosion models that leave behind a bound remnant can match some of the observed properties of SNe Iax, but no published model is consistent with all of our observations of SNe 2005hk and 2008A.

  5. Hubble space telescope and ground-based observations of the type Iax supernovae SN 2005hk and SN 2008A

    International Nuclear Information System (INIS)

    McCully, Curtis; Jha, Saurabh W.; Foley, Ryan J.; Chornock, Ryan; Holtzman, Jon A.; Balam, David D.; Branch, David; Filippenko, Alexei V.; Ganeshalingam, Mohan; Li, Weidong; Frieman, Joshua; Fynbo, Johan; Leloudas, Giorgos; Galbany, Lluis; Garnavich, Peter M.; Graham, Melissa L.; Hsiao, Eric Y.; Leonard, Douglas C.

    2014-01-01

    We present Hubble Space Telescope (HST) and ground-based optical and near-infrared observations of SN 2005hk and SN 2008A, typical members of the Type Iax class of supernovae (SNe). Here we focus on late-time observations, where these objects deviate most dramatically from all other SN types. Instead of the dominant nebular emission lines that are observed in other SNe at late phases, spectra of SNe 2005hk and 2008A show lines of Fe II, Ca II, and Fe I more than a year past maximum light, along with narrow [Fe II] and [Ca II] emission. We use spectral features to constrain the temperature and density of the ejecta, and find high densities at late times, with n e ≳ 10 9 cm –3 . Such high densities should yield enhanced cooling of the ejecta, making these objects good candidates to observe the expected 'infrared catastrophe', a generic feature of SN Ia models. However, our HST photometry of SN 2008A does not match the predictions of an infrared catastrophe. Moreover, our HST observations rule out a 'complete deflagration' that fully disrupts the white dwarf for these peculiar SNe, showing no evidence for unburned material at late times. Deflagration explosion models that leave behind a bound remnant can match some of the observed properties of SNe Iax, but no published model is consistent with all of our observations of SNe 2005hk and 2008A.

  6. Hubble Space Telescope and Ground-Based Observations of the Type Iax Supernovae SN 2005hk and SN 2008A

    Energy Technology Data Exchange (ETDEWEB)

    McCully, Curtis; Jha, Saurabh W.; Foley, Ryan J.; Chornock, Ryan; Holtzman, Jon A.; Balam, David D.; Branch, David; Filippenko, Alexei V.; Frieman, Joshua; Fynbo, Johan; Galbany, Lluis; Ganeshalingam, Mohan; Garnavich, Peter M.; Graham, Melissa L.; Hsiao, Eric Y.; Leloudas, Giorgos; Leonard, Douglas C.; Li, Weidong; Riess, Adam G.; Sako, Masao; Schneider, Donald P.; Silverman, Jeffrey M.; Sollerman, Jesper; Steele, Thea N.; Thomas, Rollin C.; Wheeler, J. Craig; Zheng, Chen

    2014-04-24

    We present Hubble Space Telescope (HST) and ground-based optical and near-infrared observations of SN 2005hk and SN 2008A, typical members of the Type Iax class of supernovae (SNe). Here we focus on late-time observations, where these objects deviate most dramatically from all other SN types. Instead of the dominant nebular emission lines that are observed in other SNe at late phases, spectra of SNe 2005hk and 2008A show lines of Fe II, Ca II, and Fe I more than a year past maximum light, along with narrow [Fe II] and [Ca II] emission. We use spectral features to constrain the temperature and density of the ejecta, and find high densities at late times, with ne109 cm–3. Such high densities should yield enhanced cooling of the ejecta, making these objects good candidates to observe the expected "infrared catastrophe," a generic feature of SN Ia models. However, our HST photometry of SN 2008A does not match the predictions of an infrared catastrophe. Moreover, our HST observations rule out a "complete deflagration" that fully disrupts the white dwarf for these peculiar SNe, showing no evidence for unburned material at late times. Deflagration explosion models that leave behind a bound remnant can match some of the observed properties of SNe Iax, but no published model is consistent with all of our observations of SNe 2005hk and 2008A.

  7. Iterative Observer-based Estimation Algorithms for Steady-State Elliptic Partial Differential Equation Systems

    KAUST Repository

    Majeed, Muhammad Usman

    2017-01-01

    the problems are formulated on higher dimensional space domains. However, in this dissertation, feedback based state estimation algorithms, known as state observers, are developed to solve such steady-state problems using one of the space variables as time

  8. Silicon carbide optics for space and ground based astronomical telescopes

    Science.gov (United States)

    Robichaud, Joseph; Sampath, Deepak; Wainer, Chris; Schwartz, Jay; Peton, Craig; Mix, Steve; Heller, Court

    2012-09-01

    Silicon Carbide (SiC) optical materials are being applied widely for both space based and ground based optical telescopes. The material provides a superior weight to stiffness ratio, which is an important metric for the design and fabrication of lightweight space telescopes. The material also has superior thermal properties with a low coefficient of thermal expansion, and a high thermal conductivity. The thermal properties advantages are important for both space based and ground based systems, which typically need to operate under stressing thermal conditions. The paper will review L-3 Integrated Optical Systems - SSG’s (L-3 SSG) work in developing SiC optics and SiC optical systems for astronomical observing systems. L-3 SSG has been fielding SiC optical components and systems for over 25 years. Space systems described will emphasize the recently launched Long Range Reconnaissance Imager (LORRI) developed for JHU-APL and NASA-GSFC. Review of ground based applications of SiC will include supporting L-3 IOS-Brashear’s current contract to provide the 0.65 meter diameter, aspheric SiC secondary mirror for the Advanced Technology Solar Telescope (ATST).

  9. Sapphire: Canada's Answer to Space-Based Surveillance of Orbital Objects

    Science.gov (United States)

    Maskell, P.; Oram, L.

    The Canadian Department of National Defence is in the process of developing the Canadian Space Surveillance System (CSSS) as the main focus of the Surveillance of Space (SofS) Project. The CSSS consists of two major elements: the Sapphire System and the Sensor System Operations Centre (SSOC). The space segment of the Sapphire System is comprised of the Sapphire Satellite - an autonomous spacecraft with an electro-optical payload which will act as a contributing sensor to the United States (US) Space Surveillance Network (SSN). It will operate in a circular, sunsynchronous orbit at an altitude of approximately 750 kilometers and image a minimum of 360 space objects daily in orbits ranging from 6,000 to 40,000 kilometers in altitude. The ground segment of the Sapphire System is composed of a Spacecraft Control Center (SCC), a Satellite Processing and Scheduling Facility (SPSF), and the Sapphire Simulator. The SPSF will be responsible for data transmission, reception, and processing while the SCC will serve to control and monitor the Sapphire Satellite. Surveillance data will be received from Sapphire through two ground stations. Following processing by the SPSF, the surveillance data will then be forwarded to the SSOC. The SSOC will function as the interface between the Sapphire System and the US Joint Space Operations Center (JSpOC). The JSpOC coordinates input from various sensors around the world, all of which are a part of the SSN. The SSOC will task the Sapphire System daily and provide surveillance data to the JSpOC for correlation with data from other SSN sensors. This will include orbital parameters required to predict future positions of objects to be tracked. The SSOC receives daily tasking instructions from the JSpOC to determine which objects the Sapphire spacecraft is required to observe. The advantage of this space-based sensor over ground-based telescopes is that weather and time of day are not factors affecting observation. Thus, space-based optical

  10. International Space Station Earth Observations Working Group

    Science.gov (United States)

    Stefanov, William L.; Oikawa, Koki

    2015-01-01

    The multilateral Earth Observations Working Group (EOWG) was chartered in May 2012 in order to improve coordination and collaboration of Earth observing payloads, research, and applications on the International Space Station (ISS). The EOWG derives its authority from the ISS Program Science Forum, and a NASA representative serves as a permanent co-chair. A rotating co-chair position can be occupied by any of the international partners, following concurrence by the other partners; a JAXA representative is the current co-chair. Primary functions of the EOWG include, 1) the exchange of information on plans for payloads, from science and application objectives to instrument development, data collection, distribution and research; 2) recognition and facilitation of opportunities for international collaboration in order to optimize benefits from different instruments; and 3) provide a formal ISS Program interface for collection and application of remotely sensed data collected in response to natural disasters through the International Charter, Space and Major Disasters. Recent examples of EOWG activities include coordination of bilateral data sharing protocols between NASA and TsNIIMash for use of crew time and instruments in support of ATV5 reentry imaging activities; discussion of continued use and support of the Nightpod camera mount system by NASA and ESA; and review and revision of international partner contributions on Earth observations to the ISS Program Benefits to Humanity publication.

  11. Gain Scheduling of Observer-Based Controllers with Integral Action

    DEFF Research Database (Denmark)

    Trangbæk, Klaus; Stoustrup, Jakob; Bendtsen, Jan Dimon

    2006-01-01

     This paper presents a method for continuous gain scheduling of  observer-based controllers with integral action. Given two stabilising controllers for a given system, explicit state space formulae are presented, allowing to change gradually from one  controller to the other while preserving...

  12. Optical observations on critical ionization velocity experiments in space

    International Nuclear Information System (INIS)

    Stenbaek-Nielsen, H.C.

    1993-01-01

    A number of Critical Ionization Velocity (CIV) experiments have been performed in space. CIV has been observed in laboratory experiments, but experiments in space have been inconclusive. Most space experiments have used barium which ionizes easily, and with emission lines from both neutrals and ions in the visible optical observations can be made from the ground. Also other elements, such as xenon, strontium and calcium, have been used. High initial ionization in some barium release experiments has been claimed due to CIV. However, a number of reactions between barium and the ambient plasma have been suggested as more likely processes. Currently the most popular process in this debate is charge exchange with O + . This process has a large cross section, but is it large enough? The cross section for charge exchange with calcium should be even larger, but in a double release of barium and calcium (part of the NASA CRRES release experiments) most ionization was observed from the barium release. Moreover, if charge exchange is the dominant process, the amount of ionization should relate to the oxygen ion density, and that does not appear to be the case. Other processes, such as associative ionization, have also been proposed, but yields are uncertain because the reaction rates are very poorly known

  13. Space- and Ground-based Coronal Spectro-Polarimetry

    Science.gov (United States)

    Fineschi, Silvano; Bemporad, Alessandro; Rybak, Jan; Capobianco, Gerardo

    This presentation gives an overview of the near-future perspectives of ultraviolet and visible-light spectro-polarimetric instrumentation for probing coronal magnetism from space-based and ground-based observatories. Spectro-polarimetric imaging of coronal emission-lines in the visible-light wavelength-band provides an important diagnostics tool of the coronal magnetism. The interpretation in terms of Hanle and Zeeman effect of the line-polarization in forbidden emission-lines yields information on the direction and strength of the coronal magnetic field. As study case, this presentation will describe the Torino Coronal Magnetograph (CorMag) for the spectro-polarimetric observation of the FeXIV, 530.3 nm, forbidden emission-line. CorMag - consisting of a Liquid Crystal (LC) Lyot filter and a LC linear polarimeter - has been recently installed on the Lomnicky Peak Observatory 20cm Zeiss coronagraph. The preliminary results from CorMag will be presented. The linear polarization by resonance scattering of coronal permitted line-emission in the ultraviolet (UV)can be modified by magnetic fields through the Hanle effect. Space-based UV spectro-polarimeters would provide an additional tool for the disgnostics of coronal magnetism. As a case study of space-borne UV spectro-polarimeters, this presentation will describe the future upgrade of the Sounding-rocket Coronagraphic Experiment (SCORE) to include the capability of imaging polarimetry of the HI Lyman-alpha, 121.6 nm. SCORE is a multi-wavelength imager for the emission-lines, HeII 30.4 nm and HI 121.6 nm, and visible-light broad-band emission of the polarized K-corona. SCORE has flown successfully in 2009. This presentation will describe how in future re-flights SCORE could observe the expected Hanle effect in corona with a HI Lyman-alpha polarimeter.

  14. An Approach to Assess Observation Impact Based on Observation-Minus-Forecast Residuals

    Science.gov (United States)

    Todling, Ricardo

    2009-01-01

    Langland and Baker (2004) introduced an approach to assess the impact of observations on the forecasts. In that, a state-space aspect of the forecast is defined and a procedure is derived that relates changes in the aspect with changes in the initial conditions associated with the assimilation of observations) ultimately providing information about the impact of individual observations on the forecast. Some features of the approach are to be noted. The typical choice of forecast aspect employed in related works is rather arbitrary and leads to an incomplete assessment of the observing system. Furthermore, the state-space forecast aspect requires availability of a verification state that should ideally be uncorrelated with the forecast but in practice is not. Lastly, the approach involves the adjoint operator of the entire data assimilation system and as such it is constrained by the validity of this operator. In this presentation, an observation-space metric is used that, for a relatively time-homogeneous observing system, allows inferring observation impact on the forecast without some of the limitations above. Specifically, using observation-minus-forecast residuals leads to an approach with the following features: (i) it suggests a rather natural choice of forecast aspect, directly linked to the analysis system and providing full assessment of the observations; (ii) it naturally avoids introducing undesirable correlations in the forecast aspect by verifying against the observations; and (iii) it does not involve linearization and use of adjoints; therefore being applicable to any length of forecast. The state and observation-space approaches might be complementary to some degree, and involve different limitations and complexities. Illustrations are given using the NASA GEOS-5 data.

  15. Space Observations for Global Change

    Science.gov (United States)

    Rasool, S. I.

    1991-01-01

    There is now compelling evidence that man's activities are changing both the composition of the atmospheric and the global landscape quite drastically. The consequences of these changes on the global climate of the 21st century is currently a hotly debated subject. Global models of a coupled Earth-ocean-atmosphere system are still very primitive and progress in this area appears largely data limited, specially over the global biosphere. A concerted effort on monitoring biospheric functions on scales from pixels to global and days to decades needs to be coordinated on an international scale in order to address the questions related to global change. An international program of space observations and ground research was described.

  16. Humanly space objects-Perception and connection with the observer

    Science.gov (United States)

    Balint, Tibor S.; Hall, Ashley

    2015-05-01

    Expanding humanity into space is an inevitable step in our quest to explore our world. Yet space exploration is costly, and the awaiting environment challenges us with extreme cold, heat, vacuum and radiation, unlike anything encountered on Earth. Thus, the few pioneers who experience it needed to be well protected throughout their spaceflight. The resulting isolation heightens the senses and increases the desire to make humanly connections with any other perceived manifestation of life. Such connections may occur via sensory inputs, namely vision, touch, sound, smell, and taste. This then follows the process of sensing, interpreting, and recognizing familiar patterns, or learning from new experiences. The desire to connect could even transfer to observed objects, if their movements and characteristics trigger the appropriate desires from the observer. When ordered in a familiar way, for example visual stimuli from lights and movements of an object, it may create a perceived real bond with an observer, and evoke the feeling of surprise when the expected behavior changes to something no longer predictable or recognizable. These behavior patterns can be designed into an object and performed autonomously in front of an observer, in our case an astronaut. The experience may introduce multiple responses, including communication, connection, empathy, order, and disorder. While emotions are clearly evoked in the observer and may seem one sided, in effect the object itself provides a decoupled bond, connectivity and communication between the observer and the artist-designer of the object. In this paper we will discuss examples from the field of arts and other domains, including robotics, where human perception through object interaction was explored, and investigate the starting point for new innovative design concepts and future prototype designs, that extend these experiences beyond the boundaries of Earth, while taking advantage of remoteness and the zero gravity

  17. Accounting for correlated observations in an age-based state-space stock assessment model

    DEFF Research Database (Denmark)

    Berg, Casper Willestofte; Nielsen, Anders

    2016-01-01

    Fish stock assessment models often relyon size- or age-specific observations that are assumed to be statistically independent of each other. In reality, these observations are not raw observations, but rather they are estimates from a catch-standardization model or similar summary statistics base...... the independence assumption is rejected. Less fluctuating estimates of the fishing mortality is obtained due to a reduced process error. The improved model does not suffer from correlated residuals unlike the independent model, and the variance of forecasts is decreased....

  18. Observation planning algorithm of a Japanese space-borne sensor: Hyperspectral Imager SUIte (HISUI) onboard International Space Station (ISS) as platform

    Science.gov (United States)

    Ogawa, Kenta; Konno, Yukiko; Yamamoto, Satoru; Matsunaga, Tsuneo; Tachikawa, Tetsushi; Komoda, Mako

    2017-09-01

    Hyperspectral Imager Suite (HISUI) is a Japanese future space-borne hyperspectral instrument being developed by Ministry of Economy, Trade, and Industry (METI). HISUI will be launched in 2019 or later onboard International Space Station (ISS) as platform. HISUI has 185 spectral band from 0.4 to 2.5 μm with 20 by 30 m spatial resolution with swath of 20 km. Swath is limited as such, however observations in continental scale area are requested in HISUI mission lifetime of three years. Therefore we are developing a scheduling algorithm to generate effective observation plans. HISUI scheduling algorithm is to generate observation plans automatically based on platform orbit, observation area maps (we say DAR; "Data Acquisition Request" in HISUI project), their priorities, and available resources and limitation of HISUI system such as instrument operation time per orbit and data transfer capability. Then next we need to set adequate DAR before start of HISUI observation, because years of observations are needed to cover continental scale wide area that is difficult to change after the mission started. To address these issues, we have developed observation simulator. The simulator's critical inputs are DAR and the ISS's orbit, HISUI limitations in observation minutes per orbit, data storage and past cloud coverage data for term of HISUI observations (3 years). Then the outputs of simulator are coverage map of each day. Areas with cloud free image are accumulated for the term of observation up to three years. We have successfully tested the simulator and tentative DAR and found that it is possible to estimate coverage for each of requests for the mission lifetime.

  19. Quantum tomography, phase-space observables and generalized Markov kernels

    International Nuclear Information System (INIS)

    Pellonpaeae, Juha-Pekka

    2009-01-01

    We construct a generalized Markov kernel which transforms the observable associated with the homodyne tomography into a covariant phase-space observable with a regular kernel state. Illustrative examples are given in the cases of a 'Schroedinger cat' kernel state and the Cahill-Glauber s-parametrized distributions. Also we consider an example of a kernel state when the generalized Markov kernel cannot be constructed.

  20. Space and Ground-Based Infrastructures

    Science.gov (United States)

    Weems, Jon; Zell, Martin

    This chapter deals first with the main characteristics of the space environment, outside and inside a spacecraft. Then the space and space-related (ground-based) infrastructures are described. The most important infrastructure is the International Space Station, which holds many European facilities (for instance the European Columbus Laboratory). Some of them, such as the Columbus External Payload Facility, are located outside the ISS to benefit from external space conditions. There is only one other example of orbital platforms, the Russian Foton/Bion Recoverable Orbital Capsule. In contrast, non-orbital weightless research platforms, although limited in experimental time, are more numerous: sounding rockets, parabolic flight aircraft, drop towers and high-altitude balloons. In addition to these facilities, there are a number of ground-based facilities and space simulators, for both life sciences (for instance: bed rest, clinostats) and physical sciences (for instance: magnetic compensation of gravity). Hypergravity can also be provided by human and non-human centrifuges.

  1. Multi-satellite observations of magnetic fields in space plasmas

    International Nuclear Information System (INIS)

    Potemra, T.A.; Zanetti, L.J.; Bythrow, P.F.; Erlandson, R.E.

    1987-01-01

    The most common method of detecting electric currents in space has been by virtue of the magnetic perturbations they produce. A satellite can pass through a field-aligned ''Birkeland'' current and measure the in-situ magnetic perturbations. Satellite-borne magnetic field experiments may also be used to observe characteristics of resonant oscillations of the Earth's magnetic field at ULF frequencies. Examples of such measurements with magnetic field experiments on the Viking, AMPTE/CCE, and DMSP-F7 satellites will be presented. The Viking satellite, launched in February, 1986, is Sweden's first satellite and is in a polar orbit with 3.1 R/sub e/ apogee. AMPTE/CCE was launched in August, 1984, with satellites from West Germany and the United Kingdom, for the purpose of creating artificial comets in space. It is in an equatorial orbit with a 8.8 R/sub e/ apogee. The Defense Meteorological Satellite Program (DMSP)-F7 satellite was launched in October, 1983 into an 800 km circular sun-synchronous orbit in the 0830-2030 magnetic local time plane. Viking and AMPTE/CCE observed harmonic ULF pulsations when they were near the same flux tube, but separated by about 10 R/sub e/. These unique observations are used to investigate the characteristics and sources of multiple field line resonances of Alfven waves. On another occasion, Viking and DMSP-F7 observed similar magnetic perturbations at widely separated locations. The authors interpret these perturbations as due to a complicated system of large-scale stable Birkeland currents in the morning sector. This multi-satellite data set is in the early stages of exploration, but already confirms the usefulness of coordinated multi-position observations of magnetic fields in space

  2. Aerosol and cloud observations from the Lidar In-space Technology Experiment

    Science.gov (United States)

    Winker, D. M.

    1995-01-01

    The Lidar In-Space Technology Experiment (LITE) is a backscatter lidar built by NASA Langley Research Center to fly on the Space Shuttle. The purpose of the program was to develop the engineering processes required for space lidar and to demonstrate applications of space lidar to remote sensing of the atmosphere. The instrument was flown on Discovery in September 1994. Global observations of clouds and aerosols were made between the latitudes of 57 deg N and 57 deg S during 10 days of the mission.

  3. Scoring sensor observations to facilitate the exchange of space surveillance data

    Science.gov (United States)

    Weigel, M.; Fiedler, H.; Schildknecht, T.

    2017-08-01

    In this paper, a scoring metric for space surveillance sensor observations is introduced. A scoring metric allows for direct comparison of data quantity and data quality, and makes transparent the effort made by different sensor operators. The concept might be applied to various sensor types like tracking and surveillance radar, active optical laser tracking, or passive optical telescopes as well as combinations of different measurement types. For each measurement type, a polynomial least squares fit is performed on the measurement values contained in the track. The track score is the average sum over the polynomial coefficients uncertainties and scaled by reference measurement accuracy. Based on the newly developed scoring metric, an accounting model and a rating model are introduced. Both models facilitate the exchange of observation data within a network of space surveillance sensors operators. In this paper, optical observations are taken as an example for analysis purposes, but both models can also be utilized for any other type of observations. The rating model has the capability to distinguish between network participants with major and minor data contribution to the network. The level of sanction on data reception is defined by the participants themselves enabling a high flexibility. The more elaborated accounting model translates the track score to credit points earned for data provision and spend for data reception. In this model, data reception is automatically limited for participants with low contribution to the network. The introduced method for observation scoring is first applied for transparent data exchange within the Small Aperture Robotic Telescope Network (SMARTnet). Therefore a detailed mathematical description is presented for line of sight measurements from optical telescopes, as well as numerical simulations for different network setups.

  4. Model-Based Trade Space Exploration for Near-Earth Space Missions

    Science.gov (United States)

    Cohen, Ronald H.; Boncyk, Wayne; Brutocao, James; Beveridge, Iain

    2005-01-01

    We developed a capability for model-based trade space exploration to be used in the conceptual design of Earth-orbiting space missions. We have created a set of reusable software components to model various subsystems and aspects of space missions. Several example mission models were created to test the tools and process. This technique and toolset has demonstrated itself to be valuable for space mission architectural design.

  5. The international earth observing system: a cultural debate about earth sciences from space

    NARCIS (Netherlands)

    Menenti, M.

    1996-01-01

    This paper gives an overview of the International Earth Observing System, i.e. the combined earth observation programmes of space agencies worldwide and of the relevance of advanced space-borne sensor systems to the study and understanding of interactions between land surface and atmosphere. The

  6. Assimilating irregularly spaced sparsely observed turbulent signals with hierarchical Bayesian reduced stochastic filters

    International Nuclear Information System (INIS)

    Brown, Kristen A.; Harlim, John

    2013-01-01

    In this paper, we consider a practical filtering approach for assimilating irregularly spaced, sparsely observed turbulent signals through a hierarchical Bayesian reduced stochastic filtering framework. The proposed hierarchical Bayesian approach consists of two steps, blending a data-driven interpolation scheme and the Mean Stochastic Model (MSM) filter. We examine the potential of using the deterministic piecewise linear interpolation scheme and the ordinary kriging scheme in interpolating irregularly spaced raw data to regularly spaced processed data and the importance of dynamical constraint (through MSM) in filtering the processed data on a numerically stiff state estimation problem. In particular, we test this approach on a two-layer quasi-geostrophic model in a two-dimensional domain with a small radius of deformation to mimic ocean turbulence. Our numerical results suggest that the dynamical constraint becomes important when the observation noise variance is large. Second, we find that the filtered estimates with ordinary kriging are superior to those with linear interpolation when observation networks are not too sparse; such robust results are found from numerical simulations with many randomly simulated irregularly spaced observation networks, various observation time intervals, and observation error variances. Third, when the observation network is very sparse, we find that both the kriging and linear interpolations are comparable

  7. Space and commodity-based society

    Directory of Open Access Journals (Sweden)

    Gvozden Vladimir

    2015-01-01

    Full Text Available The space is privileged in the commodity-based society. It is well known that the economic space in the 19th and 20th centuries rapidly managed to subordinate all other areas 'conveying and instilling in them their own meanings and goals' (G. Milatović. A new form of space that qualifies commodity society was created, marked by dualities: openness-closeness, private-public, sameness-difference. This paper is an attempt to criticize the usual analysis of the categories of commodity-space, linked to the ambivalent role of the state as a guarantor of the functioning of the commodity-based society, as well as its controlling instance. The increasing delocalisation of the political changes the nature of the space in the commodity-based society. Privileged areas are produced that create an illusion of protection of consumers (shopping malls, gated communities, theme parks, video surveillance, while at the same time social differentiation and identification are produced through the symbolic order of commodities and a sense of inclusion or exclusion from that order. At the same time, the examples of tourism and selling places demonstrate that such a commodity-space unusually easy reconciles sameness and difference. It entails uniformity to help achieve the fluctuation of goods, while insisting on the local as different, especially in terms of the role of particularity in the global trade.

  8. Solar System Observations with the James Webb Space Telescope

    OpenAIRE

    Norwood, James; Hammel, Heidi; Milam, Stefanie; Stansberry, John; Lunine, Jonathan; Chanover, Nancy; Hines, Dean; Sonneborn, George; Tiscareno, Matthew; Brown, Michael; Ferruit, Pierre

    2014-01-01

    The James Webb Space Telescope will enable a wealth of new scientific investigations in the near- and mid-infrared, with sensitivity and spatial/spectral resolution greatly surpassing its predecessors. In this paper, we focus upon Solar System science facilitated by JWST, discussing the most current information available concerning JWST instrument properties and observing techniques relevant to planetary science. We also present numerous example observing scenarios for a wide variety of Solar...

  9. Simultaneous radar and spaced receiver VHF scintillation observations of ESF irregularities

    Directory of Open Access Journals (Sweden)

    D. Tiwari

    2006-07-01

    Full Text Available Simultaneous observations of equatorial spread F (ESF irregularities made on 10 nights during March-April 1998 and 1999, using an 18-MHz radar at Trivandrum (77° E, 8.5° N, dip 0.5° N and two spaced receivers recording scintillations on a 251-MHz signal at Tirunelveli (77.8° E, 8.7° N, dip 0.4° N, have been used to study the evolution of Equatorial Spread F (ESF irregularities. Case studies have been carried out on the day-to-day variability in ESF structure and dynamics, as observed by 18-MHz radar, and with spaced receiver measurements of average zonal drift Vo of the 251-MHz radio wave diffraction pattern on the ground, random velocity Vc, which is a measure of random changes in the characteristics of scintillation-producing irregularities, and maximum cross-correlation CI of the spaced receivers signals. Results show that in the initial phase of plasma bubble development, the greater the maximum height of ESF irregularities responsible for the radar backscatter, the greater the decorrelation is of the spaced receiver scintillation signals, indicating greater turbulence. The relationship of the maximum spectral width derived from the radar observations and CI also supports this result.

  10. Astronomical Observations Astronomy and the Study of Deep Space

    CERN Document Server

    2010-01-01

    Our Search for knowledge about the universe has been remarkable, heartbreaking, fantastical, and inspiring, and this search is just beginning. Astronomical Observations is part of a 7 book series that takes readers through a virtual time warp of our discovery. From the nascent space programs of the 1960's to today's space tourism and the promise of distant planet colonization, readers will be transfixed. Throughout this journey of the mind, Earth-bound explorers gain keen insight into the celestial phenomena that have fascinated humans for centuries. Thrilling narratives about indefatigable sc

  11. Observational Model for Precision Astrometry with the Space Interferometry Mission

    National Research Council Canada - National Science Library

    Turyshev, Slava G; Milman, Mark H

    2000-01-01

    The Space Interferometry Mission (SIM) is a space-based 10-m baseline Michelson optical interferometer operating in the visible waveband that is designed to achieve astrometric accuracy in the single digits of the microarcsecond domain...

  12. Web-based description of the space radiation environment using the Bethe-Bloch model

    Science.gov (United States)

    Cazzola, Emanuele; Calders, Stijn; Lapenta, Giovanni

    2016-01-01

    Space weather is a rapidly growing area of research not only in scientific and engineering applications but also in physics education and in the interest of the public. We focus especially on space radiation and its impact on space exploration. The topic is highly interdisciplinary, bringing together fundamental concepts of nuclear physics with aspects of radiation protection and space science. We give a new approach to presenting the topic by developing a web-based application that combines some of the fundamental concepts from these two fields into a single tool that can be used in the context of advanced secondary or undergraduate university education. We present DREADCode, an outreach or teaching tool to rapidly assess the current conditions of the radiation field in space. DREADCode uses the available data feeds from a number of ongoing space missions (ACE, GOES-13, GOES-15) to produce a first order approximation of the radiation dose an astronaut would receive during a mission of exploration in deep space (i.e. far from the Earth’s shielding magnetic field and from the radiation belts). DREADCode is based on an easy-to-use GUI interface available online from the European Space Weather Portal (www.spaceweather.eu/dreadcode). The core of the radiation transport computation to produce the radiation dose from the observed fluence of radiation observed by the spacecraft fleet considered is based on a relatively simple approximation: the Bethe-Bloch equation. DREADCode also assumes a simplified geometry and material configuration for the shields used to compute the dose. The approach is approximate and sacrifices some important physics on the altar of rapid execution time, which allows a real-time operation scenario. There is no intention here to produce an operational tool for use in space science and engineering. Rather, we present an educational tool at undergraduate level that uses modern web-based and programming methods to learn some of the most important

  13. Web-based description of the space radiation environment using the Bethe–Bloch model

    International Nuclear Information System (INIS)

    Cazzola, Emanuele; Lapenta, Giovanni; Calders, Stijn

    2016-01-01

    Space weather is a rapidly growing area of research not only in scientific and engineering applications but also in physics education and in the interest of the public. We focus especially on space radiation and its impact on space exploration. The topic is highly interdisciplinary, bringing together fundamental concepts of nuclear physics with aspects of radiation protection and space science. We give a new approach to presenting the topic by developing a web-based application that combines some of the fundamental concepts from these two fields into a single tool that can be used in the context of advanced secondary or undergraduate university education. We present DREADCode, an outreach or teaching tool to rapidly assess the current conditions of the radiation field in space. DREADCode uses the available data feeds from a number of ongoing space missions (ACE, GOES-13, GOES-15) to produce a first order approximation of the radiation dose an astronaut would receive during a mission of exploration in deep space (i.e. far from the Earth’s shielding magnetic field and from the radiation belts). DREADCode is based on an easy-to-use GUI interface available online from the European Space Weather Portal (www.spaceweather.eu/dreadcode). The core of the radiation transport computation to produce the radiation dose from the observed fluence of radiation observed by the spacecraft fleet considered is based on a relatively simple approximation: the Bethe–Bloch equation. DREADCode also assumes a simplified geometry and material configuration for the shields used to compute the dose. The approach is approximate and sacrifices some important physics on the altar of rapid execution time, which allows a real-time operation scenario. There is no intention here to produce an operational tool for use in space science and engineering. Rather, we present an educational tool at undergraduate level that uses modern web-based and programming methods to learn some of the most

  14. Determining the orientation of the observed object in threedimensional space using stereo vision methods

    International Nuclear Information System (INIS)

    Ponomarev, S

    2014-01-01

    The task of matching image of an object with its template is central for many optoelectronic systems. Solution of the matching problem in three-dimensional space in contrast to the structural alignment in the image plane allows using a larger amount of information about the object for determining its orientation, which may increase the probability of correct matching. In the case of stereo vision methods for constructing a three-dimensional image of the object, it becomes possible to achieve invariance w.r.t. background and distance to the observed object. Only three of the orientation angle of the object relative to the camera are uncertain and require measurements. This paper proposes a method for determining the orientation angles of the observed object in three-dimensional space, which is based on the processing of stereo image sequences. Disparity map segmentation method that allows one to ensure the invariance of the background is presented. Quantitative estimates of the effectiveness of the proposed method are presented and discussed.

  15. Comparison of the light flash phenomena observed in space and in laboratory experiments

    International Nuclear Information System (INIS)

    McNulty, P.J.; Pease, V.P.; Bond, V.P.

    1976-01-01

    Astronauts on Apollo and Skylab missions have reported observing a variety of visual phenomena when their eyes were closed and adapted to darkness. These observations were studied under controlled conditions during a number of sessions on board Apollo and Skylab spacecraft and the data available to date on these so-called light flashes is in the form of descriptions of the phenomena and frequency of occurrence. Similar visual phenomena have been demonstrated in a number of laboratories by exposing the eyes of human subjects to beams of neutrons, alphas, pions, and protons. More than one physical mechanism is involved in the laboratory and space phenomena. No direct comparison of the laboratory and space observations has been made by observers who have experienced both. However, the range of visual phenomena observed in the laboratory is consistent with the Apollo and Skylab observations. Measured detection efficiencies can be used to estimate the frequencies with which various phenomena would be observed if the subject was exposed to cosmic rays in space

  16. Earth Observation from the International Space Station -Remote Sensing in Schools-

    Science.gov (United States)

    Schultz, Johannes; Rienow, Andreas; Graw, Valerie; Heinemann, Sascha; Selg, Fabian; Menz, Gunter

    2016-04-01

    Since spring 2014, the NASA High Definition Earth Viewing (HDEV) mission at the International Space Station (ISS) is online. HDEV consists of four cameras mounted at ESA's Columbus laboratory and is recording the earth 24/7. The educational project 'Columbus Eye - Live-Imagery from the ISS in Schools' has published a learning portal for earth observation from the ISS (www.columbuseye.uni-bonn.de). Besides a video live stream, the portal contains an archive providing spectacular footage, web-GIS and an observatory with interactive materials for school lessons. Columbus Eye is carried out by the University of Bonn and funded by the German Aerospace Center (DLR) Space Administration. Pupils should be motivated to work with the footage in order to learn about patterns and processes of the coupled human-environment system like volcano eruptions or deforestation. The material is developed on the experiences of the FIS (German abbreviation for "Remote Sensing in Schools") project and its learning portal (http://www.fis.uni-bonn.de). Based on the ISS videos three different teaching material types are developed. The simplest teaching type are provided by worksheets, which have a low degree of interactivity. Alongside a short didactical commentary for teachers is included. Additionally, videos, ancillary information, maps, and instructions for interactive school experiments are provided. The observatory contains the second type of the Columbus Eye teaching materials. It requires a high degree of self-organisation and responsibility of the pupils. Thus, the observatory provides the opportunity for pupils to freely construct their own hypotheses based on a spatial analysis tool similar to those provided by commercial software. The third type are comprehensive learning and teaching modules with a high degree of interactivity, including background information, interactive animations, quizzes and different analysis tools (e.g. change detection, classification, polygon or NDVI

  17. Hubble Space Telescope-NICMOS Observations of M31'S Metal-Rich Globular Clusters and Their Surrounding Fields. I. Techniques

    Science.gov (United States)

    Stephens, Andrew W.; Frogel, Jay A.; Freedman, Wendy; Gallart, Carme; Jablonka, Pascale; Ortolani, Sergio; Renzini, Alvio; Rich, R. Michael; Davies, Roger

    2001-05-01

    Astronomers are always anxious to push their observations to the limit-basing results on objects at the detection threshold, spectral features barely stronger than the noise, or photometry in very crowded regions. In this paper we present a careful analysis of photometry in crowded regions and show how image blending affects the results and interpretation of such data. Although this analysis is specifically for our NICMOS observations in M31, the techniques we develop can be applied to any imaging data taken in crowded fields; we show how the effects of image blending will limit even the Next Generation Space Telescope. We have obtained HST-NICMOS observations of five of M31's most metal-rich globular clusters. These data allow photometry of individual stars in the clusters and their surrounding fields. However, to achieve our goals-obtain accurate luminosity functions to compare with their Galactic counterparts, determine metallicities from the slope of the giant branch, identify long-period variables, and estimate ages from the AGB tip luminosity-we must be able to disentangle the true properties of the population from the observational effects associated with measurements made in very crowded fields. We thus use three different techniques to analyze the effects of crowding on our data, including the insertion of artificial stars (traditional completeness tests) and the creation of completely artificial clusters. These computer simulations are used to derive threshold- and critical-blending radii for each cluster, which determine how close to the cluster center reliable photometry can be achieved. The simulations also allow us to quantify and correct for the effects of blending on the slope and width of the RGB at different surface brightness levels. We then use these results to estimate the limits blending will place on future space-based observations. Based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science

  18. Earth observations during Space Shuttle flight STS-41 - Discovery's mission to planet earth

    Science.gov (United States)

    Lulla, Kamlesh P.; Helfert, Michael R.; Amsbury, David L.; Whitehead, Victor S.; Richards, Richard N.; Cabana, Robert D.; Shepherd, William M.; Akers, Thomas D.; Melnick, Bruce E.

    1991-01-01

    An overview of space flight STS-41 is presented, including personal observations and comments by the mission astronauts. The crew deployed the Ulysses spacecraft to study the polar regions of the sun and the interplanetary space above the poles. Environmental observations, including those of Lake Turkana, Lake Chad, biomass burning in Madagascar and Argentina, and circular features in Yucatan are described. Observations that include landforms and geology, continental sedimentation, desert landscapes, and river morphology are discussed.

  19. Efficient and automatic image reduction framework for space debris detection based on GPU technology

    Science.gov (United States)

    Diprima, Francesco; Santoni, Fabio; Piergentili, Fabrizio; Fortunato, Vito; Abbattista, Cristoforo; Amoruso, Leonardo

    2018-04-01

    In the last years, the increasing number of space debris has triggered the need of a distributed monitoring system for the prevention of possible space collisions. Space surveillance based on ground telescope allows the monitoring of the traffic of the Resident Space Objects (RSOs) in the Earth orbit. This space debris surveillance has several applications such as orbit prediction and conjunction assessment. In this paper is proposed an optimized and performance-oriented pipeline for sources extraction intended to the automatic detection of space debris in optical data. The detection method is based on the morphological operations and Hough Transform for lines. Near real-time detection is obtained using General Purpose computing on Graphics Processing Units (GPGPU). The high degree of processing parallelism provided by GPGPU allows to split data analysis over thousands of threads in order to process big datasets with a limited computational time. The implementation has been tested on a large and heterogeneous images data set, containing both imaging satellites from different orbit ranges and multiple observation modes (i.e. sidereal and object tracking). These images were taken during an observation campaign performed from the EQUO (EQUatorial Observatory) observatory settled at the Broglio Space Center (BSC) in Kenya, which is part of the ASI-Sapienza Agreement.

  20. Hubble Space Telescope: The Telescope, the Observations & the Servicing Mission

    Science.gov (United States)

    1999-11-01

    NICMOS enabling it to resume operation, and install a new set of solar panels. Replacement of the thermal insulation will continue and the telescope will be reboosted to a higher orbit. The plans for the fourth Servicing Mission are preliminary at this time, but two new science instruments are being developed for that mission: Cosmic Origins Spectrograph (COS), which will replace COSTAR, and Wide Field Camera 3 (WFC3), which will replace WFPC2. It is planned to retrieve Hubble at the end of its life (around 2010) and bring it back to Earth. In the future ESA may have the opportunity to continue its collaboration with NASA on the Next Generation Space Telescope (NGST), which in many ways can be seen as Hubble's successor. The plan is to launch NGST in 2008, and ESA is currently considering a possible role in the project. Piero Benvenuti concludes: "The European Space Agency, in deciding to join NASA on the HST Project, made a very successful investment on behalf of European science. Today, NASA would not consider proceeding alone on the continued operation of HST or on the design of NGST. Not just because of the benefit of shared cost, but mainly because of the intellectual contribution by the European astronomers, who have made such effective scientific use of HST." Hubble Space Telescope - Fact sheet Description The Hubble Space Telescope (HST) is a co-operation between ESA and NASA. It is a long-term space-based observatory. Its observations are carried out in visible, infrared and ultraviolet light. HST has in many ways revolutionised modern astronomy, being a highly efficient tool for making new discoveries, but also by driving astronomical research in general. Objective HST was designed to take advantage of being above the Earth's disturbing atmosphere, and thereby providing astronomers with observations of very high resolution - opening new windows on planets, stars and galaxies. HST was designed as a flagship mission of the highest standard, and has served to pave

  1. The immune system in space, including Earth-based benefits of space-based research.

    Science.gov (United States)

    Sonnenfeld, Gerald

    2005-08-01

    Exposure to space flight conditions has been shown to result in alterations in immune responses. Changes in immune responses of humans and experimental animals have been shown to be altered during and after space flight of humans and experimental animals or cell cultures of lymphoid cells. Exposure of subjects to ground-based models of space flight conditions, such as hindlimb unloading of rodents or chronic bed rest of humans, has also resulted in changes in the immune system. The relationship of these changes to compromised resistance to infection or tumors in space flight has not been fully established, but results from model systems suggest that alterations in the immune system that occur in space flight conditions may be related to decreases in resistance to infection. The establishment of such a relationship could lead to the development of countermeasures that could prevent or ameliorate any compromises in resistance to infection resulting from exposure to space flight conditions. An understanding of the mechanisms of space flight conditions effects on the immune response and development of countermeasures to prevent them could contribute to the development of treatments for compromised immunity on earth.

  2. Space Telescope and Optical Reverberation Mapping Project.I. Ultraviolet Observations of the Seyfert 1 Galaxy NGC 5548 with the Cosmic Origins Spectrograph on Hubble Space Telescope

    NARCIS (Netherlands)

    De Rosa, G.; Peterson, B.M.; Ely, J.; Kriss, G.A.; Crenshaw, D.M.; Horne, K.; Korista, K.T.; Netzer, H.; Pogge, R.W.; Arévalo, P.; Barth, A.J.; Bentz, M.C.; Brandt, W.N.; Breeveld, A.A.; Brewer, B.J.; Dalla Bontà, E.; De Lorenzo-Cáceres, A.; Denney, K.D.; Dietrich, M.; Edelson, R.; Evans, P.A.; Fausnaugh, M.M.; Gehrels, N.; Gelbord, J.M.; Goad, M.R.; Grier, C.J.; Grupe, D.; Hall, P.B.; Kaastra, J.; Kelly, B.C.; Kennea, J.A.; Kochanek, C.S.; Lira, P.; Mathur, S.; McHardy, I.M.; Nousek, J.A.; Pancoast, A.; Papadakis, I.; Pei, L.; Schimoia, J.S.; Siegel, M.; Starkey, D.; Treu, T.; Uttley, P.; Vaughan, S.; Vestergaard, M.; Villforth, C.; Yan, H.; Young, S.; Zu, Y.

    2015-01-01

    We describe the first results from a six-month long reverberation-mapping experiment in the ultraviolet based on 171 observations of the Seyfert 1 galaxy NGC 5548 with the Cosmic Origins Spectrograph on the Hubble Space Telescope. Significant correlated variability is found in the continuum and

  3. An Aerosol Extinction-to-Backscatter Ratio Database Derived from the NASA Micro-Pulse Lidar Network: Applications for Space-based Lidar Observations

    Science.gov (United States)

    Welton, Ellsworth J.; Campbell, James R.; Spinhime, James D.; Berkoff, Timothy A.; Holben, Brent; Tsay, Si-Chee; Bucholtz, Anthony

    2004-01-01

    Backscatter lidar signals are a function of both backscatter and extinction. Hence, these lidar observations alone cannot separate the two quantities. The aerosol extinction-to-backscatter ratio, S, is the key parameter required to accurately retrieve extinction and optical depth from backscatter lidar observations of aerosol layers. S is commonly defined as 4*pi divided by the product of the single scatter albedo and the phase function at 180-degree scattering angle. Values of S for different aerosol types are not well known, and are even more difficult to determine when aerosols become mixed. Here we present a new lidar-sunphotometer S database derived from Observations of the NASA Micro-Pulse Lidar Network (MPLNET). MPLNET is a growing worldwide network of eye-safe backscatter lidars co-located with sunphotometers in the NASA Aerosol Robotic Network (AERONET). Values of S for different aerosol species and geographic regions will be presented. A framework for constructing an S look-up table will be shown. Look-up tables of S are needed to calculate aerosol extinction and optical depth from space-based lidar observations in the absence of co-located AOD data. Applications for using the new S look-up table to reprocess aerosol products from NASA's Geoscience Laser Altimeter System (GLAS) will be discussed.

  4. National Coordination Office for Space-Based PNT

    Science.gov (United States)

    Shaw, M. E.

    2008-12-01

    In December 2004, President Bush issued the US Policy on space-based positioning, navigation, and timing (PNT), providing guidance on the management of the Global Positioning System (GPS) and other space- based PNT systems. The policy established the National Executive Committee (EXCOM) to advise and coordinate federal agencies on matters related to space-based PNT. Chaired jointly by the deputy secretaries of defense and transportation, the EXCOM includes equivalent level officials from the Departments of State, the Interior, Agriculture, Commerce, and Homeland Security, the Joint Chiefs of Staff, and the National Aeronautics and Space Administration (NASA). A National Coordination Office (NCO) supports the EXCOM through an interagency staff. Since establishing the EXCOM and NCO in 2005, the organizations have quickly grown in influence and effectiveness, leading or managing many interagency initiatives including the development of a Five-Year National Space-Based PNT Plan, the Space-Based PNT Interference Detection and Mitigation (IDM) Plan, and other strategic documents. The NCO has also facilitated interagency coordination on numerous policy issues and on external communications intended to spread a consistent, positive US message about space-based PNT. Role of the NCO - The purpose of the EXCOM is to provide top-level guidance to US agencies regarding space-based PNT infrastructure. The president established it at the deputy secretary level to ensure its strategic recommendations effect real change in agency budgets. Recognizing such high-level officials could only meet every few months, the president directed the EXCOM to establish an NCO to carry out its day-to-day business, including overseeing the implementation of EXCOM action items across the member agencies. These range from the resolution of funding issues to the assessment of strategic policy options. They also include the completion of specific tasks and documents requested by the EXCOM co

  5. New algorithms for optical observations of space debris with the TAROT telescopes

    Science.gov (United States)

    Laas-Bourez, Myrtille; Boer, Michel; Blanchet, Gwendoline; Ducrotte, Etienne; Klotz, Alain

    To preserve the space environment for the future, and to make space expedition safe, we have to improve our knowledge of the debris population in the vicinity of the geostationary orbit. Since 2004, CNES observes satellites in the geostationary orbit with a network of robotic ground based fully automated telescopes. One is located in France and the second being in ESO La Silla, Chile. This system makes real time processing and its wide field of view is useful for detection, systematic survey and tracking both catalogued and uncatalogued objets. We are implementing new, more efficient, image processing algorithms. A new source extraction algorithm based on morphological mathematic, and a "matching-pursuit" algorithm allow to correlate the measurements of the same object on successive images and give an almost nil false detection rate. These new methods allow us to detect objects on the geostationary belt and on other orbits like MEO or GTO. We also improved the timing precision of individual images (few milliseconds) and the precision of the position restitution respective to the celestial frame. Our "delay card" provides an extremely precise date of objects in a picture and our new algorithm accurately extracts stars from background for calibration; Thanks to all these improvements, the overall efficiency and quality of the survey of the geostationary orbit has drastically improved and we can now detect satellites and debris in different orbits like GTO orbit. In this paper we present our new methods and the work we have made for the detection of space debris: the images dating with a card of delay, the accuracy of astronomical calibration, and the robustness of the extracting space debris with different algorithms. The results obtained on the sky will be shown.

  6. Simultaneous radar and spaced receiver VHF scintillation observations of ESF irregularities

    Directory of Open Access Journals (Sweden)

    D. Tiwari

    2006-07-01

    Full Text Available Simultaneous observations of equatorial spread F (ESF irregularities made on 10 nights during March-April 1998 and 1999, using an 18-MHz radar at Trivandrum (77° E, 8.5° N, dip 0.5° N and two spaced receivers recording scintillations on a 251-MHz signal at Tirunelveli (77.8° E, 8.7° N, dip 0.4° N, have been used to study the evolution of Equatorial Spread F (ESF irregularities. Case studies have been carried out on the day-to-day variability in ESF structure and dynamics, as observed by 18-MHz radar, and with spaced receiver measurements of average zonal drift Vo of the 251-MHz radio wave diffraction pattern on the ground, random velocity Vc, which is a measure of random changes in the characteristics of scintillation-producing irregularities, and maximum cross-correlation CI of the spaced receivers signals. Results show that in the initial phase of plasma bubble development, the greater the maximum height of ESF irregularities responsible for the radar backscatter, the greater the decorrelation is of the spaced receiver scintillation signals, indicating greater turbulence. The relationship of the maximum spectral width derived from the radar observations and CI also supports this result.

  7. Orthonormal bases for α-modulation spaces

    DEFF Research Database (Denmark)

    Nielsen, Morten

    We construct an orthonormal basis for the family of bi-variate a-modulation spaces. The construction is based on local trigonometric bases, and the basis elements are closely related to so-called brushlets. As an application, we show that m-term nonlinear approximation with the system in an a......-modulation space can be completely characterized....

  8. An International Disaster Management SensorWeb Consisting of Space-based and Insitu Sensors

    Science.gov (United States)

    Mandl, D.; Frye, S. W.; Policelli, F. S.; Cappelaere, P. G.

    2009-12-01

    For the past year, NASA along with partners consisting of the United Nations Space-based Information for Disaster and Emergency Response (UN-SPIDER) office, the Canadian Space Agency, the Ukraine Space Research Institute (SRI), Taiwan National Space Program Office (NSPO) and in conjunction with the Committee on Earth Observing Satellite (CEOS) Working Group on Information Systems and Services (WGISS) have been conducting a pilot project to automate the process of obtaining sensor data for the purpose of flood management and emergency response. This includes experimenting with flood prediction models based on numerous meteorological satellites and a global hydrological model and then automatically triggering follow up high resolution satellite imagery with rapid delivery of data products. This presentation will provide a overview of the effort, recent accomplishments and future plans.

  9. Poster: Observing change in crowded data sets in 3D space - Visualizing gene expression in human tissues

    KAUST Repository

    Rogowski, Marcin

    2013-03-01

    We have been confronted with a real-world problem of visualizing and observing change of gene expression between different human tissues. In this paper, we are presenting a universal representation space based on two-dimensional gel electrophoresis as opposed to force-directed layouts encountered most often in similar problems. We are discussing the methods we devised to make observing change more convenient in a 3D virtual reality environment. © 2013 IEEE.

  10. Ground-truth aerosol lidar observations: can the Klett solutions obtained from ground and space be equal for the same aerosol case?

    International Nuclear Information System (INIS)

    Ansmann, Albert

    2006-01-01

    Upcoming multiyear satellite lidar aerosol observations need strong support by a worldwide ground-truth lidar network. In this context the question arises as to whether the ground stations can deliver the same results as obtained from space when the Klett formalism is applied to elastic backscatter lidar data for the same aerosol case. This question is investigated based on simulations of observed cases of simple and complex aerosol layering. The results show that the differences between spaceborne and ground-based observations can be as large as20% for the backscatter and extinction coefficients and the optimum estimates of the column lidar ratios. In cases with complex aerosol layering, the application of the two-layer approach can lead to similar results (space, ground) and accurate products provided that horizontally homogeneous aerosol conditions are given

  11. Space-borne observation of mesospheric bore by Visible and near Infrared Spectral Imager onboard the International Space Station

    Science.gov (United States)

    Hozumi, Y.; Saito, A.; Sakanoi, T.; Yamazaki, A.; Hosokawa, K.

    2017-12-01

    Mesospheric bores were observed by Visible and near Infrared Spectral Imager (VISI) of the ISS-IMAP mission (Ionosphere, Mesosphere, upper Atmosphere and Plasmasphere mapping mission from the International Space Station) in O2 airglow at 762 nm wavelength. The mesospheric bore is moving front of sharp jump followed by undulations or turbulence in the mesopause region. Since previous studies of mesospheric bore were mainly based on ground-based airglow imaging that is limited in field-of-view and observing site, little is known about its horizontal extent and global behavior. Space-borne imaging by ISS-IMAP/VISI provides an opportunity to study the mesospheric bore with a wide field-of-view and global coverage. A mesospheric bore was captured by VISI in two consecutive paths on 9 July 2015 over the south of African continent (48ºS - 54ºS and 15ºE). The wave front aligned with south-north direction and propagated to west. The phase velocity and wave length of the following undulation were estimated to 100 m/s and 30 km, respectively. Those parameters are similar to those reported by previous studies. 30º anti-clockwise rotation of the wave front was recognized in 100 min. Another mesospheric bore was captured on 9 May 2013 over the south Atlantic ocean (35ºS - 43ºS and 24ºW - 1ºE) with more than 2,200 km horizontal extent of wave front. The wave front aligned with southeast-northwest direction. Because the following undulation is recognized in the southwest side of the wave front, it is estimated to propagate to northeast direction. The wave front was modulated with 1,000 km wave length. This modulation implies inhomogeneity of the phase velocity.

  12. In-Space Internet-Based Communications for Space Science Platforms Using Commercial Satellite Networks

    Science.gov (United States)

    Kerczewski, Robert J.; Bhasin, Kul B.; Fabian, Theodore P.; Griner, James H.; Kachmar, Brian A.; Richard, Alan M.

    1999-01-01

    The continuing technological advances in satellite communications and global networking have resulted in commercial systems that now can potentially provide capabilities for communications with space-based science platforms. This reduces the need for expensive government owned communications infrastructures to support space science missions while simultaneously making available better service to the end users. An interactive, high data rate Internet type connection through commercial space communications networks would enable authorized researchers anywhere to control space-based experiments in near real time and obtain experimental results immediately. A space based communications network architecture consisting of satellite constellations connecting orbiting space science platforms to ground users can be developed to provide this service. The unresolved technical issues presented by this scenario are the subject of research at NASA's Glenn Research Center in Cleveland, Ohio. Assessment of network architectures, identification of required new or improved technologies, and investigation of data communications protocols are being performed through testbed and satellite experiments and laboratory simulations.

  13. High resolution solar observations in the context of space weather prediction

    Science.gov (United States)

    Yang, Guo

    Space weather has a great impact on the Earth and human life. It is important to study and monitor active regions on the solar surface and ultimately to predict space weather based on the Sun's activity. In this study, a system that uses the full power of speckle masking imaging by parallel processing to obtain high-spatial resolution images of the solar surface in near real-time has been developed and built. The application of this system greatly improves the ability to monitor the evolution of solar active regions and to predict the adverse effects of space weather. The data obtained by this system have also been used to study fine structures on the solar surface and their effects on the upper solar atmosphere. A solar active region has been studied using high resolution data obtained by speckle masking imaging. Evolution of a pore in an active region presented. Formation of a rudimentary penumbra is studied. The effects of the change of the magnetic fields on the upper level atmosphere is discussed. Coronal Mass Ejections (CMEs) have a great impact on space weather. To study the relationship between CMEs and filament disappearance, a list of 431 filament and prominence disappearance events has been compiled. Comparison of this list with CME data obtained by satellite has shown that most filament disappearances seem to have no corresponding CME events. Even for the limb events, only thirty percent of filament disappearances are associated with CMEs. A CME event that was observed on March 20, 2000 has been studied in detail. This event did not show the three-parts structure of typical CMEs. The kinematical and morphological properties of this event were examined.

  14. Space-based infrared sensors of space target imaging effect analysis

    Science.gov (United States)

    Dai, Huayu; Zhang, Yasheng; Zhou, Haijun; Zhao, Shuang

    2018-02-01

    Target identification problem is one of the core problem of ballistic missile defense system, infrared imaging simulation is an important means of target detection and recognition. This paper first established the space-based infrared sensors ballistic target imaging model of point source on the planet's atmosphere; then from two aspects of space-based sensors camera parameters and target characteristics simulated atmosphere ballistic target of infrared imaging effect, analyzed the camera line of sight jitter, camera system noise and different imaging effects of wave on the target.

  15. Space construction base control system

    Science.gov (United States)

    1978-01-01

    Aspects of an attitude control system were studied and developed for a large space base that is structurally flexible and whose mass properties change rather dramatically during its orbital lifetime. Topics of discussion include the following: (1) space base orbital pointing and maneuvering; (2) angular momentum sizing of actuators; (3) momentum desaturation selection and sizing; (4) multilevel control technique applied to configuration one; (5) one-dimensional model simulation; (6) N-body discrete coordinate simulation; (7) structural analysis math model formulation; and (8) discussion of control problems and control methods.

  16. Phase space properties of charged fields in theories of local observables

    International Nuclear Information System (INIS)

    Buchholz, D.; D'Antoni, C.

    1994-10-01

    Within the setting of algebraic quantum field theory a relation between phase-space properties of observables and charged fields is established. These properties are expressed in terms of compactness and nuclarity conditions which are the basis for the characterization of theories with physically reasonable causal and thermal features. Relevant concepts and results of phase space analysis in algebraic qunatum field theory are reviewed and the underlying ideas are outlined. (orig.)

  17. StreakDet data processing and analysis pipeline for space debris optical observations

    Science.gov (United States)

    Virtanen, Jenni; Flohrer, Tim; Muinonen, Karri; Granvik, Mikael; Torppa, Johanna; Poikonen, Jonne; Lehti, Jussi; Santti, Tero; Komulainen, Tuomo; Naranen, Jyri

    We describe a novel data processing and analysis pipeline for optical observations of space debris. The monitoring of space object populations requires reliable acquisition of observational data, to support the development and validation of space debris environment models, the build-up and maintenance of a catalogue of orbital elements. In addition, data is needed for the assessment of conjunction events and for the support of contingency situations or launches. The currently available, mature image processing algorithms for detection and astrometric reduction of optical data cover objects that cross the sensor field-of-view comparably slowly, and within a rather narrow, predefined range of angular velocities. By applying specific tracking techniques, the objects appear point-like or as short trails in the exposures. However, the general survey scenario is always a “track before detect” problem, resulting in streaks, i.e., object trails of arbitrary lengths, in the images. The scope of the ESA-funded StreakDet (Streak detection and astrometric reduction) project is to investigate solutions for detecting and reducing streaks from optical images, particularly in the low signal-to-noise ratio (SNR) domain, where algorithms are not readily available yet. For long streaks, the challenge is to extract precise position information and related registered epochs with sufficient precision. Although some considerations for low-SNR processing of streak-like features are available in the current image processing and computer vision literature, there is a need to discuss and compare these approaches for space debris analysis, in order to develop and evaluate prototype implementations. In the StreakDet project, we develop algorithms applicable to single images (as compared to consecutive frames of the same field) obtained with any observing scenario, including space-based surveys and both low- and high-altitude populations. The proposed processing pipeline starts from the

  18. Iterative observer based method for source localization problem for Poisson equation in 3D

    KAUST Repository

    Majeed, Muhammad Usman

    2017-07-10

    A state-observer based method is developed to solve point source localization problem for Poisson equation in a 3D rectangular prism with available boundary data. The technique requires a weighted sum of solutions of multiple boundary data estimation problems for Laplace equation over the 3D domain. The solution of each of these boundary estimation problems involves writing down the mathematical problem in state-space-like representation using one of the space variables as time-like. First, system observability result for 3D boundary estimation problem is recalled in an infinite dimensional setting. Then, based on the observability result, the boundary estimation problem is decomposed into a set of independent 2D sub-problems. These 2D problems are then solved using an iterative observer to obtain the solution. Theoretical results are provided. The method is implemented numerically using finite difference discretization schemes. Numerical illustrations along with simulation results are provided.

  19. Space based microlensing planet searches

    Directory of Open Access Journals (Sweden)

    Tisserand Patrick

    2013-04-01

    Full Text Available The discovery of extra-solar planets is arguably the most exciting development in astrophysics during the past 15 years, rivalled only by the detection of dark energy. Two projects unite the communities of exoplanet scientists and cosmologists: the proposed ESA M class mission EUCLID and the large space mission WFIRST, top ranked by the Astronomy 2010 Decadal Survey report. The later states that: “Space-based microlensing is the optimal approach to providing a true statistical census of planetary systems in the Galaxy, over a range of likely semi-major axes”. They also add: “This census, combined with that made by the Kepler mission, will determine how common Earth-like planets are over a wide range of orbital parameters”. We will present a status report of the results obtained by microlensing on exoplanets and the new objectives of the next generation of ground based wide field imager networks. We will finally discuss the fantastic prospect offered by space based microlensing at the horizon 2020–2025.

  20. CONCEPTION OF ONTOLOGY-BASED SECTOR EDUCATIONAL SPACE

    Directory of Open Access Journals (Sweden)

    V. I. Khabarov

    2014-09-01

    Full Text Available PurposeThe aim of the research is to demonstrate the need for the Conception of Ontology-based Sector Educational Space. This Conception could become the basis for the integration of transport sector university information resources into the open virtual network information resource and global educational space. Its content will be presented by standardized ontology-based knowledge packages for educational programs in Russian and English languages.MethodologyComplex-based, ontological, content-based approaches and scientific principles of interdisciplinarity and standardization of knowledge are suggested as the methodological basis of the research. ResultsThe Conception of Ontology-based Sector Educational Space (railway transport, the method of the development of knowledge packages as ontologies in Russian and English languages, the Russian-English Transport Glossary as a separate ontology are among the expected results of the project implementation.Practical implicationsThe Conception could become the basis for the open project to establish the common resource center for transport universities (railway transport. The Conception of ontology-based sector educational space (railway transport could be adapted to the activity of universities of other economic sectors.

  1. Using observational methods to evaluate public open spaces and physical activity in Brazil.

    Science.gov (United States)

    Hino A A, F; Reis, Rodrigo S; Ribeiro, Isabela C; Parra, Diana C; Brownson, Ross C; Fermino, Rogerio C

    2010-07-01

    Open public spaces have been identified as important facilities to promote physical activity (PA) at the community level. The main goals of this study are to describe open public spaces user's characteristics and to explore to what extent these characteristics are associated with PA behavior. A system of direct observation was used to evaluate the PA levels on parks and squares (smaller parks) and users's characteristics (gender and age). The 4 parks and 4 squares observed were selected from neighborhoods with different socioeconomic status and environmental characteristics. The settings were observed 3 times a day, 6 days per week, during 2 weeks. More men than women were observed in parks (63.1%) and squares (70.0%) as well as more adults and adolescents than older adults and children. Users were more physically active in parks (men = 34.1%, women = 36.1%) than in squares (men = 25.5%, women 22.8%). The characteristics of public open spaces may affect PA in the observed places. Initiatives to improve PA levels in community settings should consider users' characteristics and preferences to be more effective and reach a larger number of people.

  2. Time Series Analysis of Non-Gaussian Observations Based on State Space Models from Both Classical and Bayesian Perspectives

    NARCIS (Netherlands)

    Durbin, J.; Koopman, S.J.M.

    1998-01-01

    The analysis of non-Gaussian time series using state space models is considered from both classical and Bayesian perspectives. The treatment in both cases is based on simulation using importance sampling and antithetic variables; Monte Carlo Markov chain methods are not employed. Non-Gaussian

  3. Earth observation space programmes, SAFISY activities, strategies of international organisations, legal aspects. Volume 3

    International Nuclear Information System (INIS)

    1992-01-01

    This volume is separated in four sessions. First part is on earth observation space programmes (international earth observation projects and international collaboration, the ERS-1, SPOT and PRIRODA programmes, the first ESA earth observation polar platform and its payload, the future earth observation remote sensing techniques and concepts). The second part is on SAFISY activities (ISY programmes, education and applications, demonstrations and outreach projects). The third part is on programme and strategies of international organisations with respect to earth observation from space. The fourth part is on legal aspects of the use of satellite remote sensing data in Europe. (A.B.). refs., figs., tabs

  4. Transferring Knowledge from a Bird's-Eye View - Earth Observation and Space Travels in Schools

    Science.gov (United States)

    Rienow, Andreas; Hodam, Henryk; Menz, Gunter; Voß, Kerstin

    2014-05-01

    In spring 2014, four commercial cameras will be transported by a Dragon spacecraft to the International Space Station (ISS) and mounted to the ESA Columbus laboratory. The cameras will deliver live earth observation data from different angles. The "Columbus-Eye"* project aims at distributing the video and image data produced by those cameras through a web portal. It should primary serve as learning portal for pupils comprising teaching material around the ISS earth observation imagery. The pupils should be motivated to work with the images in order to learn about curriculum relevant topics of natural sciences. The material will be prepared based on the experiences of the FIS* (German abbreviation for "Remote Sensing in Schools") project and its learning portal. Recognizing that in-depth use of satellite imagery can only be achieved by the means of computer aided learning methods, a sizeable number of e-Learning contents in German and English have been created throughout the last 5 years since FIS' kickoff. The talk presents the educational valorization of remote sensing data as well as their interactive implementation for teachers and pupils in both learning portals. It will be shown which possibilities the topic of remote sensing holds ready for teaching the regular curricula of Geography, Biology, Physics, Math and Informatics. Beside the sequenced implementation into digital and interactive teaching units, examples of a richly illustrated encyclopedia as well as easy-to-use image processing tools are given. The presentation finally addresses the question of how synergies of space travels can be used to enhance the fascination of earth observation imagery in the light of problem-based learning in everyday school lessons.

  5. Primary Dendrite Array Morphology: Observations from Ground-based and Space Station Processed Samples

    Science.gov (United States)

    Tewari, Surendra; Rajamure, Ravi; Grugel, Richard; Erdmann, Robert; Poirier, David

    2012-01-01

    Influence of natural convection on primary dendrite array morphology during directional solidification is being investigated under a collaborative European Space Agency-NASA joint research program, "Microstructure Formation in Castings of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions (MICAST)". Two Aluminum-7 wt pct Silicon alloy samples, MICAST6 and MICAST7, were directionally solidified in microgravity on the International Space Station. Terrestrially grown dendritic monocrystal cylindrical samples were remelted and directionally solidified at 18 K/cm (MICAST6) and 28 K/cm (MICAST7). Directional solidification involved a growth speed step increase (MICAST6-from 5 to 50 micron/s) and a speed decrease (MICAST7-from 20 to 10 micron/s). Distribution and morphology of primary dendrites is currently being characterized in these samples, and also in samples solidified on earth under nominally similar thermal gradients and growth speeds. Primary dendrite spacing and trunk diameter measurements from this investigation will be presented.

  6. UniSat-5: a space-based optical system for space debris monitoring

    Science.gov (United States)

    Di Roberto, Riccardo; Cappelletti, Chantal

    2012-07-01

    Micro-satellite missions, thanks to the miniaturization process of electronic components, now have a broader range of applications. Gauss Group at School of Aerospace Engineering has been a pioneer in educational micro-satellites, namely with UNISAT and EDUSAT missions. Moreover it has been long involved in space debris related studies, such as optical observations as well as mitigation. A new project is under development for a compact digital imaging system. The purpose will be in situ observation of space debris on board Unisat-5 micro-satellite. One of the key elements of observing on orbit is that many atmospheric phenomena would be avoided, such as diffraction and EM absorption. Hence images would gain more contrast and solar spectral irradiance would be higher for the whole visible spectrum Earlier limitations of power and instrument size prevented the inclusion of these payloads in educational satellite missions. The system is composed of an optical tube, a camera, C band and S band transceivers and two antennas. The system is independent from the rest of the spacecraft. The optical tube is a Schmidt-Cassegrain reflector, and the magnitude limit is 13. The camera is equipped with a panchromatic 5Mpix sensor, capable of direct video streaming, as well as local storage of recorded images. The transceivers operate on ISM 2.4GHz and 5 GHz Wi-Fi bands, and they provide stand-alone communication capabilities to the payload, and Unisat-5 OBDH can switch between the two. Both transceivers are connected to their respective custom-designed patch antenna. The ground segment is constituted of a high gain antenna dish, which will use the same transceiver on board the spacecraft as the feed, in order to establish a TCP/IP wireless link. Every component of this system is a consumer grade product. Therefore price reduction of cutting edge imaging technology now allows the use of professional instruments, that combined with the new wireless technology developed for

  7. Orthonormal bases for anisotropic α-modulation spaces

    DEFF Research Database (Denmark)

    Rasmussen, Kenneth Niemann

    2012-01-01

    In this article we construct orthonormal bases for bi-variate anisotropic α-modulation spaces. The construction is based on generating a nice anisotropic α-covering and using carefully selected tensor products of univariate brushlet functions with regards to this covering. As an application, we...... show that n-term nonlinear approximation with the orthonormal bases in certain anisotropic α-modulation spaces can be completely characterized....

  8. Orthonormal bases for anisotropic α-modulation spaces

    DEFF Research Database (Denmark)

    Rasmussen, Kenneth Niemann

    In this article we construct orthonormal bases for bi-variate anisotropic α-modulation spaces. The construction is based on generating a nice anisotropic α-covering and using carefully selected tensor products of univariate brushlet functions with regards to this covering. As an application, we...... show that n-term nonlinear approximation with the orthonormal bases in certain anisotropic α-modulation spaces can be completely characterized....

  9. Nuclear reactor power as applied to a space-based radar mission

    Science.gov (United States)

    Jaffe, L.; Fujita, T.; Beatty, R.; Bhandari, P.; Chow, E.; Deininger, W.; Ewell, R.; Grossman, M.; Kia, T.; Nesmith, B.

    1988-01-01

    The SP-100 Project was established to develop and demonstrate feasibility of a space reactor power system (SRPS) at power levels of 10's of kilowatts to a megawatt. To help determine systems requirements for the SRPS, a mission and spacecraft were examined which utilize this power system for a space-based radar to observe moving objects. Aspects of the mission and spacecraft bearing on the power system were the primary objectives of this study; performance of the radar itself was not within the scope. The study was carried out by the Systems Design Audit Team of the SP-100 Project.

  10. Space-Based Observation Technology

    Science.gov (United States)

    2000-10-01

    Analysis of P-band Synthetic Aperture Radar for Airborne and Spaceborne Applications 40 by A. Potsis, N. Uzunoglou, P. Frangos , R. Horn and K...P. Frangos . G. Jäger and U. Benz Image Content Dependent Compression of SAR Data 50† by U. Benz, J.V. Fischer and G. Jaeger An Embedded Fusion...Uzunoglou, ‘P. Frangos , 2R. Horn, 2K. Lumprecht ‘National Technical University of Athens. Department Of Electrical And Computer Engineering 9 Iroon

  11. Orthonormal bases for  α-modulation spaces

    DEFF Research Database (Denmark)

    Nielsen, Morten

    2010-01-01

    We construct an orthonormal basis for the family of bi-variate α-modulation spaces. The construction is based on local trigonometric bases, and the basis elements are closely related to so-called brushlets. As an application, we show that m-term nonlinear approximation with the representing system...... in an α-modulation space can be completely characterized....

  12. Fractal systems of central places based on intermittency of space-filling

    International Nuclear Information System (INIS)

    Chen Yanguang

    2011-01-01

    Highlights: → The idea of intermittency is introduced into central place model. → The revised central place model suggests incomplete space filling. → New central place fractals are presented for urban analysis. → The average nearest distance is proposed to estimate the fractal dimension. → The concept of distance-based space is replaced by that of dimension-based space. - Abstract: The central place models are fundamentally important in theoretical geography and city planning theory. The texture and structure of central place networks have been demonstrated to be self-similar in both theoretical and empirical studies. However, the underlying rationale of central place fractals in the real world has not yet been revealed so far. This paper is devoted to illustrating the mechanisms by which the fractal patterns can be generated from central place systems. The structural dimension of the traditional central place models is d = 2 indicating no intermittency in the spatial distribution of human settlements. This dimension value is inconsistent with empirical observations. Substituting the complete space filling with the incomplete space filling, we can obtain central place models with fractional dimension D < d = 2 indicative of spatial intermittency. Thus the conventional central place models are converted into fractal central place models. If we further integrate the chance factors into the improved central place fractals, the theory will be able to explain the real patterns of urban places very well. As empirical analyses, the US cities and towns are employed to verify the fractal-based models of central places.

  13. Space-Based Diagnosis of Surface Ozone Sensitivity to Anthropogenic Emissions

    Science.gov (United States)

    Martin, Randall V.; Fiore, Arlene M.; VanDonkelaar, Aaron

    2004-01-01

    We present a novel capability in satellite remote sensing with implications for air pollution control strategy. We show that the ratio of formaldehyde columns to tropospheric nitrogen dioxide columns is an indicator of the relative sensitivity of surface ozone to emissions of nitrogen oxides (NO(x) = NO + NO2) and volatile organic compounds (VOCs). The diagnosis from these space-based observations is highly consistent with current understanding of surface ozone chemistry based on in situ observations. The satellite-derived ratios indicate that surface ozone is more sensitive to emissions of NO(x) than of VOCs throughout most continental regions of the Northern Hemisphere during summer. Exceptions include Los Angeles and industrial areas of Germany. A seasonal transition occurs in the fall when surface ozone becomes less sensitive to NOx and more sensitive to VOCs.

  14. A Novel Controller Design for the Next Generation Space Electrostatic Accelerometer Based on Disturbance Observation and Rejection.

    Science.gov (United States)

    Li, Hongyin; Bai, Yanzheng; Hu, Ming; Luo, Yingxin; Zhou, Zebing

    2016-12-23

    The state-of-the-art accelerometer technology has been widely applied in space missions. The performance of the next generation accelerometer in future geodesic satellites is pushed to 8 × 10 - 13 m / s 2 / H z 1 / 2 , which is close to the hardware fundamental limit. According to the instrument noise budget, the geodesic test mass must be kept in the center of the accelerometer within the bounds of 56 pm / Hz 1 / 2 by the feedback controller. The unprecedented control requirements and necessity for the integration of calibration functions calls for a new type of control scheme with more flexibility and robustness. A novel digital controller design for the next generation electrostatic accelerometers based on disturbance observation and rejection with the well-studied Embedded Model Control (EMC) methodology is presented. The parameters are optimized automatically using a non-smooth optimization toolbox and setting a weighted H-infinity norm as the target. The precise frequency performance requirement of the accelerometer is well met during the batch auto-tuning, and a series of controllers for multiple working modes is generated. Simulation results show that the novel controller could obtain not only better disturbance rejection performance than the traditional Proportional Integral Derivative (PID) controllers, but also new instrument functions, including: easier tuning procedure, separation of measurement and control bandwidth and smooth control parameter switching.

  15. A Novel Controller Design for the Next Generation Space Electrostatic Accelerometer Based on Disturbance Observation and Rejection

    Directory of Open Access Journals (Sweden)

    Hongyin Li

    2016-12-01

    Full Text Available The state-of-the-art accelerometer technology has been widely applied in space missions. The performance of the next generation accelerometer in future geodesic satellites is pushed to 8 × 10 − 13 m / s 2 / H z 1 / 2 , which is close to the hardware fundamental limit. According to the instrument noise budget, the geodesic test mass must be kept in the center of the accelerometer within the bounds of 56 pm / Hz 1 / 2 by the feedback controller. The unprecedented control requirements and necessity for the integration of calibration functions calls for a new type of control scheme with more flexibility and robustness. A novel digital controller design for the next generation electrostatic accelerometers based on disturbance observation and rejection with the well-studied Embedded Model Control (EMC methodology is presented. The parameters are optimized automatically using a non-smooth optimization toolbox and setting a weighted H-infinity norm as the target. The precise frequency performance requirement of the accelerometer is well met during the batch auto-tuning, and a series of controllers for multiple working modes is generated. Simulation results show that the novel controller could obtain not only better disturbance rejection performance than the traditional Proportional Integral Derivative (PID controllers, but also new instrument functions, including: easier tuning procedure, separation of measurement and control bandwidth and smooth control parameter switching.

  16. Estimation of vegetation photosynthetic capacity from space-based measurements of chlorophyll fluorescence for terrestrial biosphere models.

    Science.gov (United States)

    Zhang, Yongguang; Guanter, Luis; Berry, Joseph A; Joiner, Joanna; van der Tol, Christiaan; Huete, Alfredo; Gitelson, Anatoly; Voigt, Maximilian; Köhler, Philipp

    2014-12-01

    Photosynthesis simulations by terrestrial biosphere models are usually based on the Farquhar's model, in which the maximum rate of carboxylation (Vcmax ) is a key control parameter of photosynthetic capacity. Even though Vcmax is known to vary substantially in space and time in response to environmental controls, it is typically parameterized in models with tabulated values associated to plant functional types. Remote sensing can be used to produce a spatially continuous and temporally resolved view on photosynthetic efficiency, but traditional vegetation observations based on spectral reflectance lack a direct link to plant photochemical processes. Alternatively, recent space-borne measurements of sun-induced chlorophyll fluorescence (SIF) can offer an observational constraint on photosynthesis simulations. Here, we show that top-of-canopy SIF measurements from space are sensitive to Vcmax at the ecosystem level, and present an approach to invert Vcmax from SIF data. We use the Soil-Canopy Observation of Photosynthesis and Energy (SCOPE) balance model to derive empirical relationships between seasonal Vcmax and SIF which are used to solve the inverse problem. We evaluate our Vcmax estimation method at six agricultural flux tower sites in the midwestern US using spaced-based SIF retrievals. Our Vcmax estimates agree well with literature values for corn and soybean plants (average values of 37 and 101 μmol m(-2)  s(-1) , respectively) and show plausible seasonal patterns. The effect of the updated seasonally varying Vcmax parameterization on simulated gross primary productivity (GPP) is tested by comparing to simulations with fixed Vcmax values. Validation against flux tower observations demonstrate that simulations of GPP and light use efficiency improve significantly when our time-resolved Vcmax estimates from SIF are used, with R(2) for GPP comparisons increasing from 0.85 to 0.93, and for light use efficiency from 0.44 to 0.83. Our results support the use of

  17. Discrete phase space based on finite fields

    International Nuclear Information System (INIS)

    Gibbons, Kathleen S.; Hoffman, Matthew J.; Wootters, William K.

    2004-01-01

    The original Wigner function provides a way of representing in phase space the quantum states of systems with continuous degrees of freedom. Wigner functions have also been developed for discrete quantum systems, one popular version being defined on a 2Nx2N discrete phase space for a system with N orthogonal states. Here we investigate an alternative class of discrete Wigner functions, in which the field of real numbers that labels the axes of continuous phase space is replaced by a finite field having N elements. There exists such a field if and only if N is a power of a prime; so our formulation can be applied directly only to systems for which the state-space dimension takes such a value. Though this condition may seem limiting, we note that any quantum computer based on qubits meets the condition and can thus be accommodated within our scheme. The geometry of our NxN phase space also leads naturally to a method of constructing a complete set of N+1 mutually unbiased bases for the state space

  18. MASS MEASUREMENTS OF ISOLATED OBJECTS FROM SPACE-BASED MICROLENSING

    DEFF Research Database (Denmark)

    Zhu, Wei; Novati, S. Calchi; Gould, A.

    2016-01-01

    lies behind the same amount of dust as the Bulge red clump, we find the lens is a 45 ± 7 {M}{{J}} BD at 5.9 ± 1.0 kpc. The lens of of the second event, OGLE-2015-BLG-0763, is a 0.50 ± 0.04 {M}⊙ star at 6.9 ± 1.0 kpc. We show that the probability to definitively measure the mass of isolated microlenses...... is dramatically increased once simultaneous ground- and space-based observations are conducted....

  19. Deep Space Habitat Configurations Based on International Space Station Systems

    Science.gov (United States)

    Smitherman, David; Russell, Tiffany; Baysinger, Mike; Capizzo, Pete; Fabisinski, Leo; Griffin, Brand; Hornsby, Linda; Maples, Dauphne; Miernik, Janie

    2012-01-01

    A Deep Space Habitat (DSH) is the crew habitation module designed for long duration missions. Although humans have lived in space for many years, there has never been a habitat beyond low-Earth-orbit. As part of the Advanced Exploration Systems (AES) Habitation Project, a study was conducted to develop weightless habitat configurations using systems based on International Space Station (ISS) designs. Two mission sizes are described for a 4-crew 60-day mission, and a 4-crew 500-day mission using standard Node, Lab, and Multi-Purpose Logistics Module (MPLM) sized elements, and ISS derived habitation systems. These durations were selected to explore the lower and upper bound for the exploration missions under consideration including a range of excursions within the Earth-Moon vicinity, near earth asteroids, and Mars orbit. Current methods for sizing the mass and volume for habitats are based on mathematical models that assume the construction of a new single volume habitat. In contrast to that approach, this study explored the use of ISS designs based on existing hardware where available and construction of new hardware based on ISS designs where appropriate. Findings included a very robust design that could be reused if the DSH were assembled and based at the ISS and a transportation system were provided for its return after each mission. Mass estimates were found to be higher than mathematical models due primarily to the use of multiple ISS modules instead of one new large module, but the maturity of the designs using flight qualified systems have potential for improved cost, schedule, and risk benefits.

  20. Observing at-surface irradiance and albedo from space : The Tibet experiment

    NARCIS (Netherlands)

    Roupioz, L.

    2015-01-01

    Monitoring the solar radiation budget on a daily basis is a prerequisite to study land surface processes, especially in climatology and hydrology, and in derived applications like drought early warning. Current space-born radiometers can provide daily observations to derive surface radiative fluxes

  1. Comparison of Ground- and Space-based Radar Observations with Disdrometer Measurements During the PECAN Field Campaign

    Science.gov (United States)

    Torres, A. D.; Rasmussen, K. L.; Bodine, D. J.; Dougherty, E.

    2015-12-01

    Plains Elevated Convection At Night (PECAN) was a large field campaign that studied nocturnal mesoscale convective systems (MCSs), convective initiation, bores, and low-level jets across the central plains in the United States. MCSs are responsible for over half of the warm-season precipitation across the central U.S. plains. The rainfall from deep convection of these systems over land have been observed to be underestimated by satellite radar rainfall-retrieval algorithms by as much as 40 percent. These algorithms have a strong dependence on the generally unmeasured rain drop-size distribution (DSD). During the campaign, our group measured rainfall DSDs, precipitation fall velocities, and total precipitation in the convective and stratiform regions of MCSs using Ott Parsivel optical laser disdrometers. The disdrometers were co-located with mobile pod units that measured temperature, wind, and relative humidity for quality control purposes. Data from the operational NEXRAD radar in LaCrosse, Wisconsin and space-based radar measurements from a Global Precipitation Measurement satellite overpass on July 13, 2015 were used for the analysis. The focus of this study is to compare DSD measurements from the disdrometers to radars in an effort to reduce errors in existing rainfall-retrieval algorithms. The error analysis consists of substituting measured DSDs into existing quantitative precipitation estimation techniques (e.g. Z-R relationships and dual-polarization rain estimates) and comparing these estimates to ground measurements of total precipitation. The results from this study will improve climatological estimates of total precipitation in continental convection that are used in hydrological studies, climate models, and other applications.

  2. Results of Joint Observations of Jupiter's Atmosphere by Juno and a Network of Earth-Based Observing Stations

    Science.gov (United States)

    Orton, G. S.; Momary, T.; Tabataba-Vakili, F.; Bolton, S.; Levin, S.; Adriani, A.; Gladstone, G. R.; Hansen, C. J.; Janssen, M.

    2017-09-01

    Well over sixty investigator/instrument investigations are actively engaged in the support of the Juno mission. These observations range from X-ray to the radio wavelengths and involve both space- and ground-based astronomical facilities. These observations enhance and expand Juno measurements by (1) providing a context that expands the area covered by often narrow spatial coverage of Juno's instruments, (2) providing a temporal context that shows how phenomena evolve over Juno's 53-day orbit period, (3) providing observations in spectral ranges not covered by Juno's instruments, and (4) monitoring the behavior of external influences to Jupiter's magnetosphere. Intercommunication between the Juno scientists and the support program is maintained by reference to a Google table that describes the observation and its current status, as well as by occasional group emails. A non-interactive version of this invitation-only site is mirrored in a public site. Several sets of these supporting observations are described at this meeting.

  3. Hubble Space Telescope STIS observations of GRB 000301C: CCD imaging and near-ultraviolet MAMA spectroscopy

    DEFF Research Database (Denmark)

    Smette, A.; Fruchter, A.S.; Gull, T.R.

    2001-01-01

    We present Space Telescope Imaging Spectrograph observations of the optical transient (OT) counterpart of the c-ray burster GRB 000301C obtained 5 days after the burst, on 2000 March 6. CCD clear-aperture imaging reveals a R similar or equal to 21.50 +/- 0.15 source with no apparent host galaxy...... Telescope images appear to lie on the stellar field of a host galaxy, and as the large H I column density measured here and in later ground-based observations is unlikely on a random line of sight, we believe we are probably seeing absorption from H I in the host galaxy. In any case, this represents...

  4. A digital beamforming processor for the joint DoD/NASA space based radar mission

    Science.gov (United States)

    Fischman, Mark A.; Le, Charles; Rosen, Paul A.

    2004-01-01

    The Space Based Radar (SBR) program includes a joint technology demonstration between NASA and the Air Force to design a low-earth orbiting, 2x50 m L-band radar system for both Earth science and intelligence related observations.

  5. Extreme covariant quantum observables in the case of an Abelian symmetry group and a transitive value space

    International Nuclear Information System (INIS)

    Haapasalo, Erkka Theodor; Pellonpaeae, Juha-Pekka

    2011-01-01

    We represent quantum observables as normalized positive operator valued measures and consider convex sets of observables which are covariant with respect to a unitary representation of a locally compact Abelian symmetry group G. The value space of such observables is a transitive G-space. We characterize the extreme points of covariant observables and also determine the covariant extreme points of the larger set of all quantum observables. The results are applied to position, position difference, and time observables.

  6. Just in Time in Space or Space Based JIT

    Science.gov (United States)

    VanOrsdel, Kathleen G.

    1995-01-01

    Our satellite systems are mega-buck items. In today's cost conscious world, we need to reduce the overall costs of satellites if our space program is to survive. One way to accomplish this would be through on-orbit maintenance of parts on the orbiting craft. In order to accomplish maintenance at a low cost I advance the hypothesis of having parts and pieces (spares) waiting. Waiting in the sense of having something when you need it, or just-in-time. The JIT concept can actually be applied to space processes. Its definition has to be changed just enough to encompass the needs of space. Our space engineers tell us which parts and pieces the satellite systems might be needing once in orbit. These items are stored in space for the time of need and can be ready when they are needed -- or Space Based JIT. When a system has a problem, the repair facility is near by and through human or robotics intervention, it can be brought back into service. Through a JIT process, overall system costs could be reduced as standardization of parts is built into satellite systems to facilitate reduced numbers of parts being stored. Launch costs will be contained as fewer spare pieces need to be included in the launch vehicle and the space program will continue to thrive even in this era of reduced budgets. The concept of using an orbiting parts servicer and human or robotics maintenance/repair capabilities would extend satellite life-cycle and reduce system replacement launches. Reductions of this nature throughout the satellite program result in cost savings.

  7. Seasonal variation of spherical aerosols distribution in East Asia based on ground and space Lidar observation and a Chemical transport model

    Science.gov (United States)

    Hara, Y.; Yumimoto, K.; Uno, I.; Shimizu, A.; Sugimoto, N.; Ohara, T.

    2009-12-01

    The anthropogenic aerosols largely impact on not only human health but also global climate system, therefore air pollution in East Asia due to a rapid economic growth has been recognized as a significant environmental problem. Several international field campaigns had been conducted to elucidate pollutant gases, aerosols characteristics and radiative forcing in East Asia. (e.g., ACE-Asia, TRACE-P, ADEC, EAREX 2005). However, these experiments were mainly conducted in springtime, therefore seasonal variation of aerosols distribution has not been clarified well yet. National Institute for Environmental Studies (NIES) has been constructing a lidar networks by automated dual wavelength / polarization Mie-lidar systems to observe the atmospheric environment in Asian region since 2001. Furthermore, from June 2006, space-borne backscatter lidar, Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), onboard NASA/CALIPSO satellite, measures continuous global aerosol and cloud vertical distribution with very high spatial resolution. In this paper, we will show the seasonal variation of aerosols distribution in East Asia based on the NIES lidar network observation, Community Multi-scale Air Quality Modeling System (CMAQ) chemical transport model simulation and CALIOP observation over the period from July 2006 to December 2008. We found that CMAQ result explains the typical seasonal aerosol characteristics by lidar observations. For example, CMAQ and ground lidar showed a summertime peak of aerosol optical thickness (AOT) at Beijing, an autumn AOT peak at Guangzhou and summertime AOT trough at Hedo, Okinawa. These characteristics are mainly controlled by seasonal variations of Asian summer/winter monsoon system. We also examined the CMAQ seasonal average aerosol extinction profiles with ground lidar and CALIOP extinction data. These comparisons clarified that the CMAQ reproduced the observed aerosol layer depth well in the downwind region. Ground lidar and CALIOP seasonal

  8. Ground Radar Polarimetric Observations of High-Frequency Earth-Space Communication Links

    Science.gov (United States)

    Bolen, Steve; Chandrasekar, V.; Benjamin, Andrew

    2002-01-01

    Strategic roadmaps for NASA's Human Exploration and Development of Space (REDS) enterprise support near-term high-frequency communication systems that provide moderate to high data rates with dependable service. Near-earth and human planetary exploration will baseline Ka-Band, but may ultimately require the use of even higher frequencies. Increased commercial demand on low-frequency earth-space bands has also led to increased interest in the use of higher frequencies in regions like K u - and K,- band. Data is taken from the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR), which operates at 13.8 GHz, and the true radar reflectivity profile is determined along the PR beam via low-frequency ground based polarimetric observations. The specific differential phase (Kdp) is measured along the beam and a theoretical model is used to determine the expected specific attenuation (k). This technique, called the k-Kdp method, uses a Fuzzy-Logic model to determine the hydrometeor type along the PR beam from which the appropriate k-Kdp relationship is used to determine k and, ultimately, the total path-integrated attenuation (PIA) on PR measurements. Measurements from PR and the NCAR S-POL radar were made during the TEFLUN-B experiment that took place near Melbourne, FL in 1998, and the TRMM-LBA campaign near Ji-Parana, Brazil in 1999.

  9. Hand gesture recognition in confined spaces with partial observability and occultation constraints

    Science.gov (United States)

    Shirkhodaie, Amir; Chan, Alex; Hu, Shuowen

    2016-05-01

    Human activity detection and recognition capabilities have broad applications for military and homeland security. These tasks are very complicated, however, especially when multiple persons are performing concurrent activities in confined spaces that impose significant obstruction, occultation, and observability uncertainty. In this paper, our primary contribution is to present a dedicated taxonomy and kinematic ontology that are developed for in-vehicle group human activities (IVGA). Secondly, we describe a set of hand-observable patterns that represents certain IVGA examples. Thirdly, we propose two classifiers for hand gesture recognition and compare their performance individually and jointly. Finally, we present a variant of Hidden Markov Model for Bayesian tracking, recognition, and annotation of hand motions, which enables spatiotemporal inference to human group activity perception and understanding. To validate our approach, synthetic (graphical data from virtual environment) and real physical environment video imagery are employed to verify the performance of these hand gesture classifiers, while measuring their efficiency and effectiveness based on the proposed Hidden Markov Model for tracking and interpreting dynamic spatiotemporal IVGA scenarios.

  10. The Future of Space Astronomy.

    Science.gov (United States)

    Field, George B.

    1984-01-01

    Discusses various aspects of space astronomy, considering advantages, the space telescope and ground-based astronomy, an orbiting astrophysics facility, solar physics, and other areas. Indicates that earth-based astronomy will continue to be carried out there and space astronomy will be limited to observations that can be carried out only from…

  11. A telescope for observation from space of extreme lightnings in the upper atmosphere

    International Nuclear Information System (INIS)

    Nam, S.; Artikova, S.; Chung, T.; Garipov, G.; Jeon, J.A.; Jeong, S.; Jin, J.Y.; Khrenov, B.A.; Kim, J.E.; Kim, M.; Kim, Y.K.; Klimov, P.; Lee, J.; Lee, H.Y.; Na, G.W.; Oh, S.J.; Panasyuk, M.; Park, I.H.; Park, J.H.; Park, Y.-S.

    2008-01-01

    A new type of telescope with a wide field-of-view and functions of fast zoom-in has been introduced. Two kinds of MEMS (Micro-Electro-Mechanical Systems) micromirrors, digital and analog, are used for reflectors of the telescope, placed at different focal lengths. We apply this technology to the observation from space of TLE (Transient Luminous Events), extremely large transient sparks occurring at the upper atmosphere. TLE are one type of important backgrounds to be understood for future space observation of UHECR (Ultra-High Energy Cosmic Rays). The launch of the payload carried by a Russian microsatellite is foreseen in the middle of 2008

  12. Depolarization ratio of polar stratospheric clouds in coastal Antarctica: comparison analysis between ground-based Micro Pulse Lidar and space-borne CALIOP observations

    Directory of Open Access Journals (Sweden)

    C. Córdoba-Jabonero

    2013-03-01

    Full Text Available Polar stratospheric clouds (PSCs play an important role in polar ozone depletion, since they are involved in diverse ozone destruction processes (chlorine activation, denitrification. The degree of that ozone reduction is depending on the type of PSCs, and hence on their occurrence. Therefore PSC characterization, mainly focused on PSC-type discrimination, is widely demanded. The backscattering (R and volume linear depolarization (δV ratios are the parameters usually used in lidar measurements for PSC detection and identification. In this work, an improved version of the standard NASA/Micro Pulse Lidar (MPL-4, which includes a built-in depolarization detection module, has been used for PSC observations above the coastal Antarctic Belgrano II station (Argentina, 77.9° S 34.6° W, 256 m a.s.l. since 2009. Examination of the MPL-4 δV feature as a suitable index for PSC-type discrimination is based on the analysis of the two-channel data, i.e., the parallel (p- and perpendicular (s- polarized MPL signals. This study focuses on the comparison of coincident δV-profiles as obtained from ground-based MPL-4 measurements during three Antarctic winters with those reported from the space-borne lidar CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization aboard the CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation satellite in the same period (83 simultaneous cases are analysed for 2009–2011 austral winter times. Three different approaches are considered for the comparison analysis between both lidar profile data sets in order to test the degree of agreement: the correlation coefficient (CC, as a measure of the relationship between both PSC vertical structures; the mean differences together with their root mean square (RMS values found between data sets; and the percentage differences (BIAS, parameter also used in profiling comparisons between CALIOP and other ground-based lidar systems. All of them are examined as a function

  13. NASA space station automation: AI-based technology review

    Science.gov (United States)

    Firschein, O.; Georgeff, M. P.; Park, W.; Neumann, P.; Kautz, W. H.; Levitt, K. N.; Rom, R. J.; Poggio, A. A.

    1985-01-01

    Research and Development projects in automation for the Space Station are discussed. Artificial Intelligence (AI) based automation technologies are planned to enhance crew safety through reduced need for EVA, increase crew productivity through the reduction of routine operations, increase space station autonomy, and augment space station capability through the use of teleoperation and robotics. AI technology will also be developed for the servicing of satellites at the Space Station, system monitoring and diagnosis, space manufacturing, and the assembly of large space structures.

  14. Using and Experiencing the Academic Library: A Multisite Observational Study of Space and Place

    Science.gov (United States)

    May, Francine; Swabey, Alice

    2015-01-01

    This study examines how students are using academic library spaces and the role these spaces are playing in the campus community. Data were collected on five campuses (two community colleges, two undergraduate universities, and one technical institute) via observational seating sweeps and questionnaires. The study found remarkably similar usage…

  15. Future Missions for Space Weather Specifications and Forecasts

    Science.gov (United States)

    Onsager, T. G.; Biesecker, D. A.; Anthes, R. A.; Maier, M. W.; Gallagher, F. W., III; St Germain, K.

    2017-12-01

    The progress of technology and the global integration of our economic and security infrastructures have introduced vulnerabilities to space weather that demand a more comprehensive ability to specify and to predict the dynamics of the space environment. This requires a comprehensive network of real-time space-based and ground-based observations with long-term continuity. In order to determine the most cost effective space architectures for NOAA's weather, space weather, and environmental missions, NOAA conducted the NOAA Satellite Observing System Architecture (NSOSA) study. This presentation will summarize the process used to document the future needs and the relative priorities for NOAA's operational space-based observations. This involves specifying the most important observations, defining the performance attributes at different levels of capability, and assigning priorities for achieving the higher capability levels. The highest priority observations recommended by the Space Platform Requirements Working Group (SPRWG) for improvement above a minimal capability level will be described. Finally, numerous possible satellite architectures have been explored to assess the costs and benefits of various architecture configurations.

  16. Activity-Based Collaboration for Interactive Spaces

    DEFF Research Database (Denmark)

    Bardram, Jakob Eyvind; Esbensen, Morten; Tabard, Aurélien

    2017-01-01

    , folder, documents, etc., users are able to interact with ‘activities’ which encapsulate files and other low-level resources. In ABC an ‘activity’ can be shared between collaborating users and can be accessed on different devices. As such, ABC is a framework that suits the requirements of designing...... interactive spaces. This chapter provides an overview of ABC with a special focus on its support for collaboration (‘Activity Sharing’) and multiple devices (‘Activity Roaming’). These ABC concepts are illustrated as implemented in two different interactive spaces technologies; ReticularSpaces [1] and the e......LabBench [2, 3]. The chapter discusses the benefits of activity-based collaboration support for these interactive spaces, while also discussing limitations and challenges to be addressed in further research....

  17. An expert systems application to space base data processing

    Science.gov (United States)

    Babb, Stephen M.

    1988-01-01

    The advent of space vehicles with their increased data requirements are reflected in the complexity of future telemetry systems. Space based operations with its immense operating costs will shift the burden of data processing and routine analysis from the space station to the Orbital Transfer Vehicle (OTV). A research and development project is described which addresses the real time onboard data processing tasks associated with a space based vehicle, specifically focusing on an implementation of an expert system.

  18. Calocube—A highly segmented calorimeter for a space based experiment

    International Nuclear Information System (INIS)

    D'Alessandro, R.; Adriani, O.; Agnesi, A.; Albergo, S.; Auditore, L.; Basti, A.; Berti, E.; Bigongiari, G.; Bonechi, L.; Bonechi, S.; Bongi, M.; Bonvicini, V.

    2016-01-01

    Future research in High Energy Cosmic Ray Physics concerns fundamental questions on their origin, acceleration mechanism, and composition. Unambiguous measurements of the energy spectra and of the composition of cosmic rays at the “knee” region could provide some of the answers to the above questions. Only ground based observations, which rely on sophisticated models describing high energy interactions in the earth's atmosphere, have been possible so far due to the extremely low particle rates at these energies. A calorimeter based space experiment can provide not only flux measurements but also energy spectra and particle identification, especially when coupled to a dE/dx measuring detector, and thus overcome some of the limitations plaguing ground based experiments. For this to be possible very large acceptances are needed if enough statistic is to be collected in a reasonable time. This contrasts with the lightness and compactness requirements for space based experiments. A novel idea in calorimetry is discussed here which addresses these issues while limiting the mass and volume of the detector. In fact a small prototype is currently being built and tested with ions. In this paper the results obtained will be presented in light of the simulations performed.

  19. Calocube—A highly segmented calorimeter for a space based experiment

    Energy Technology Data Exchange (ETDEWEB)

    D' Alessandro, R., E-mail: candi@fi.infn.it [University of Florence, Department of Physics and Astronomy, via G. Sansone 1, I-50019 Sesto Fiorentino (Firenze) (Italy); INFN Firenze, via B. Rossi 1, I-50019 Sesto Fiorentino (Firenze) (Italy); Adriani, O. [University of Florence, Department of Physics and Astronomy, via G. Sansone 1, I-50019 Sesto Fiorentino (Firenze) (Italy); INFN Firenze, via B. Rossi 1, I-50019 Sesto Fiorentino (Firenze) (Italy); Agnesi, A. [University of Pavia, Dipartimento di Ingegneria Industriale e dell' Informazione, Pavia (Italy); INFN Pavia, via A. Bassi 6, I-27100 Pavia (Italy); Albergo, S. [University of Catania, Department of Physics and Astronomy, via S. Sofia 64, I-95123 Catania (Italy); INFN Catania, via S. Sofia 64, I-95123 Catania (Italy); Auditore, L. [University of Messina, Department of Physics, sal. Sperone 31, I-98166 Messina (Italy); INFN Catania, via S. Sofia 64, I-95123 Catania (Italy); Basti, A. [University of Siena, Department of Physical Sciences, Earth and Environment, I-53100 Siena (Italy); INFN Pisa, via F. Buonarroti 2, I-56127 Pisa (Italy); Berti, E. [University of Florence, Department of Physics and Astronomy, via G. Sansone 1, I-50019 Sesto Fiorentino (Firenze) (Italy); INFN Firenze, via B. Rossi 1, I-50019 Sesto Fiorentino (Firenze) (Italy); Bigongiari, G. [University of Siena, Department of Physical Sciences, Earth and Environment, I-53100 Siena (Italy); INFN Pisa, via F. Buonarroti 2, I-56127 Pisa (Italy); Bonechi, L. [INFN Firenze, via B. Rossi 1, I-50019 Sesto Fiorentino (Firenze) (Italy); Bonechi, S. [University of Siena, Department of Physical Sciences, Earth and Environment, I-53100 Siena (Italy); INFN Pisa, via F. Buonarroti 2, I-56127 Pisa (Italy); Bongi, M. [University of Florence, Department of Physics and Astronomy, via G. Sansone 1, I-50019 Sesto Fiorentino (Firenze) (Italy); INFN Firenze, via B. Rossi 1, I-50019 Sesto Fiorentino (Firenze) (Italy); Bonvicini, V. [INFN Trieste, via Valerio 2, I-34127 Trieste (Italy); and others

    2016-07-11

    Future research in High Energy Cosmic Ray Physics concerns fundamental questions on their origin, acceleration mechanism, and composition. Unambiguous measurements of the energy spectra and of the composition of cosmic rays at the “knee” region could provide some of the answers to the above questions. Only ground based observations, which rely on sophisticated models describing high energy interactions in the earth's atmosphere, have been possible so far due to the extremely low particle rates at these energies. A calorimeter based space experiment can provide not only flux measurements but also energy spectra and particle identification, especially when coupled to a dE/dx measuring detector, and thus overcome some of the limitations plaguing ground based experiments. For this to be possible very large acceptances are needed if enough statistic is to be collected in a reasonable time. This contrasts with the lightness and compactness requirements for space based experiments. A novel idea in calorimetry is discussed here which addresses these issues while limiting the mass and volume of the detector. In fact a small prototype is currently being built and tested with ions. In this paper the results obtained will be presented in light of the simulations performed.

  20. Direct convertor based upon space charge effects

    International Nuclear Information System (INIS)

    Gitomer, S.J.

    1977-01-01

    A device capable of converting directly the kinetic energy of charged particles into electrical energy is considered. The device differs from earlier ones (such as Post's periodic focus electrostatic direct convertor) in that it makes use of the space charge repulsion in a high density charged particle beam. The beam is directed into a monotonic decelerating electrostatic field of a several-stage planar-finned structure. The collector fins coincide with vacuum equipotential surfaces. Space charge blowup of the beam directs particles onto various collector fins. The energy efficiency of a 4-stage device has been determined using a numberical simulation approach. We find that efficiencies approaching 75 percent are possible. An approximate scaling law is derived for the space charge based direct converter and a comparison is made to the periodic focus direct convertor. We find the space charge based direct convertor to be superior to a number of ways

  1. The Global Geodetic Observing System: Space Geodesy Networks for the Future

    Science.gov (United States)

    Pearlman, Michael; Pavlis, Erricos; Ma, Chopo; Altamini, Zuheir; Noll, Carey; Stowers, David

    2011-01-01

    Ground-based networks of co-located space geodetic techniques (VLBI, SLR, GNSS. and DORIS) are the basis for the development and maintenance of the International Terrestrial Reference frame (ITRF), which is our metric of reference for measurements of global change, The Global Geodetic Observing System (GGOS) of the International Association of Geodesy (IAG) has established a task to develop a strategy to design, integrate and maintain the fundamental geodetic network and supporting infrastructure in a sustainable way to satisfy the long-term requirements for the reference frame. The GGOS goal is an origin definition at 1 mm or better and a temporal stability on the order of 0.1 mm/y, with similar numbers for the scale and orientation components. These goals are based on scientific requirements to address sea level rise with confidence, but other applications are not far behind. Recent studies including one by the US National Research Council has strongly stated the need and the urgency for the fundamental space geodesy network. Simulations are underway to examining accuracies for origin, scale and orientation of the resulting ITRF based on various network designs and system performance to determine the optimal global network to achieve this goal. To date these simulations indicate that 24 - 32 co-located stations are adequate to define the reference frame and a more dense GNSS and DORIS network will be required to distribute the reference frame to users anywhere on Earth. Stations in the new global network will require geologically stable sites with good weather, established infrastructure, and local support and personnel. GGOS wil seek groups that are interested in participation. GGOS intends to issues a Call for Participation of groups that would like to contribute in the network implementation and operation. Some examples of integrated stations currently in operation or under development will be presented. We will examine necessary conditions and challenges in

  2. Possible Space-Based Gravitational-Wave Observatory Mission Concept

    Science.gov (United States)

    Livas, Jeffrey C.

    2015-08-01

    The existence of gravitational waves was established by the discovery of the Binary Pulsar PSR 1913+16 by Hulse and Taylor in 1974, for which they were awarded the 1983 Nobel Prize. However, it is the exploitation of these gravitational waves for the extraction of the astrophysical parameters of the sources that will open the first new astronomical window since the development of gamma ray telescopes in the 1970’s and enable a new era of discovery and understanding of the Universe. Direct detection is expected in at least two frequency bands from the ground before the end of the decade with Advanced LIGO and Pulsar Timing Arrays. However, many of the most exciting sources will be continuously observable in the band from 0.1-100 mHz, accessible only from space due to seismic noise and gravity gradients in that band that disturb ground-based observatories. This talk will discuss a possible mission concept developed from the original Laser Interferometer Space Antenna (LISA) reference mission but updated to reduce risk and cost.

  3. Space-Based Remote Sensing of the Earth: A Report to the Congress

    Science.gov (United States)

    1987-01-01

    The commercialization of the LANDSAT Satellites, remote sensing research and development as applied to the Earth and its atmosphere as studied by NASA and NOAA is presented. Major gaps in the knowledge of the Earth and its atmosphere are identified and a series of space based measurement objectives are derived. The near-term space observations programs of the United States and other countries are detailed. The start is presented of the planning process to develop an integrated national program for research and development in Earth remote sensing for the remainder of this century and the many existing and proposed satellite and sensor systems that the program may include are described.

  4. Space weather effects on ground based technology

    Science.gov (United States)

    Clark, T.

    Space weather can affect a variety of forms of ground-based technology, usually as a result of either the direct effects of the varying geomagnetic field, or as a result of the induced electric field that accompanies such variations. Technologies affected directly by geomagnetic variations include magnetic measurements made d ringu geophysical surveys, and navigation relying on the geomagnetic field as a direction reference, a method that is particularly common in the surveying of well-bores in the oil industry. The most obvious technology affected by induced electric fields during magnetic storms is electric power transmission, where the example of the blackout in Quebec during the March 1989 magnetic storm is widely known. Additionally, space weather effects must be taken into account in the design of active cathodic protection systems on pipelines to protect them against corrosion. Long-distance telecommunication cables may also have to be designed to cope with space weather related effects. This paper reviews the effects of space weather in these different areas of ground-based technology, and provides examples of how mitigation against hazards may be achieved. (The paper does not include the effects of space weather on radio communication or satellite navigation systems).

  5. Fermi Coordinates of an Observer Moving in a Circle in Minkowski Space: Apparent Behavior of Clocks

    National Research Council Canada - National Science Library

    Bahder, Thomas

    2000-01-01

    Space-time coordinate transformations valid for arbitrarily long coordinate time are derived from global Minkowski coordinates to the Fermi coordinates of an observer moving in a circle in three-dimensional space...

  6. Laboratory Observation of Electron Phase-Space Holes during Magnetic Reconnection

    International Nuclear Information System (INIS)

    Fox, W.; Porkolab, M.; Egedal, J.; Katz, N.; Le, A.

    2008-01-01

    We report the observation of large-amplitude, nonlinear electrostatic structures, identified as electron phase-space holes, during magnetic reconnection experiments on the Versatile Toroidal Facility at MIT. The holes are positive electric potential spikes, observed on high-bandwidth (∼2 GHz) Langmuir probes. Investigations with multiple probes establish that the holes travel at or above the electron thermal speed and have a three-dimensional, approximately spherical shape, with a scale size ∼2 mm. This corresponds to a few electron gyroradii, or many tens of Debye lengths, which is large compared to holes considered in simulations and observed by satellites, whose length scale is typically only a few Debye lengths. Finally, a statistical study over many discharges confirms that the holes appear in conjunction with the large inductive electric fields and the creation of energetic electrons associated with the magnetic energy release

  7. Double layers in space

    International Nuclear Information System (INIS)

    Carlqvist, P.

    1982-07-01

    For more than a decade it has been realised that electrostatic double layers are likely to occur in space. We briefly discuss the theoretical background of such double layers. Most of the paper is devoted to an account of the observational evidence for double layers in the ionosphere and magnetosphere of the Earth. Several different experiments are reviewed including rocket and satellite measurements and ground based observations. It is concluded that the observational evidence for double layers in space is very strong. The experimental results indicate that double layers with widely different properties may exist in space. (Author)

  8. Double layers in space

    International Nuclear Information System (INIS)

    Carlqvist, P.

    1982-01-01

    For more than a decade it has been realised that electrostatic double layers are likely to occur in space. The author briefly discusses the theoretical background of such double layers. Most of the paper is devoted to an account of the observational evidence for double layers in the ionosphere and magnetosphere of the Earth. Several different experiments are reviewed including rocket and satellite measurements and ground based observations. It is concluded that the observational evidence for double layers in space is very strong. The experimental results indicate that double layers with widely different properties may exist in space. (Auth.)

  9. Space Weather and Real-Time Monitoring

    Directory of Open Access Journals (Sweden)

    S Watari

    2009-04-01

    Full Text Available Recent advance of information and communications technology enables to collect a large amount of ground-based and space-based observation data in real-time. The real-time data realize nowcast of space weather. This paper reports a history of space weather by the International Space Environment Service (ISES in association with the International Geophysical Year (IGY and importance of real-time monitoring in space weather.

  10. HUBBLE SPACE TELESCOPE AND GROUND-BASED OBSERVATIONS OF V455 ANDROMEDAE POST-OUTBURST

    Energy Technology Data Exchange (ETDEWEB)

    Szkody, Paula; Mukadam, Anjum S.; Brown, Justin; Funkhouser, Kelsey [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Gänsicke, Boris T. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Henden, Arne [AAVSO, 49 Bay State Road, Cambridge, MA 02138 (United States); Sion, Edward M. [Department of Astronomy and Astrophysics, Villanova University, Villanova, PA 19085 (United States); Townsley, Dean M. [Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL 35487 (United States); Christian, Damian [Department of Physics and Astronomy, California State University, Northridge, CA 91330 (United States); Falcon, Ross E. [Department of Astronomy, University of Texas, Austin, TX 78712 (United States); Pyrzas, Stylianos, E-mail: szkody@astro.washington.edu, E-mail: anjum@astro.washington.edu, E-mail: boris.gaensicke@warwick.ac.uk, E-mail: arne@aavso.org, E-mail: edward.sion@villanova.edu, E-mail: Dean.M.Townsley@ua.edu, E-mail: damian.christian@csun.edu, E-mail: cylver@astro.as.utexas.edu, E-mail: stylianos.pyrzas@gmail.com [Instituto de Astronomia, Universidad Catolica del Norte, Avenida Angamos 0619, Antofagasta (Chile)

    2013-09-20

    Hubble Space Telescope spectra obtained in 2010 and 2011, 3 and 4 yr after the large amplitude dwarf nova outburst of V455 And, were combined with optical photometry and spectra to study the cooling of the white dwarf, its spin, and possible pulsation periods after the outburst. The modeling of the ultraviolet (UV) spectra shows that the white dwarf temperature remains ∼600 K hotter than its quiescent value at 3 yr post-outburst, and still a few hundred degrees hotter at 4 yr post-outburst. The white dwarf spin at 67.6 s and its second harmonic at 33.8 s are visible in the optical within a month of outburst and are obvious in the later UV observations in the shortest wavelength continuum and the UV emission lines, indicating an origin in high-temperature regions near the accretion curtains. The UV light curves folded on the spin period show a double-humped modulation consistent with two-pole accretion. The optical photometry 2 yr after outburst shows a group of frequencies present at shorter periods (250-263 s) than the periods ascribed to pulsation at quiescence, and these gradually shift toward the quiescent frequencies (300-360 s) as time progresses past outburst. The most surprising result is that the frequencies near this period in the UV data are only prominent in the emission lines, not the UV continuum, implying an origin away from the white dwarf photosphere. Thus, the connection of this group of periods with non-radial pulsations of the white dwarf remains elusive.

  11. Earth observations from space: History, promise, and reality. Executive summary

    Science.gov (United States)

    1995-01-01

    In this report the Committee on Earth Studies (CES), a standing committee of the Space Studies Board (SSB) within the National Research Council (NRC), reviews the recent history (nominally from 1981 to 1995) of the U.S. earth observations programs that serve civilian needs. The principal observations programs examined are those of NASA and the National Oceanic and Atmospheric Administration (NOAA). The Air Force' s Defense Meteorological Satellite Program (DMSP) is discussed, but only from the perspective of its relationship to civil needs and the planned merger with the NOAA polar-orbiting system. The report also reviews the interfaces between the earth observations satellite programs and the major national and international environmental monitoring and research programs. The monitoring and research programs discussed are the U.S. Global Change Research Program (USGCRP), the International Geosphere-Biosphere Program (IGBP), the World Climate Research Program (WCRP), related international scientific campaigns, and operational programs for the sharing and application of environmental data. The purpose of this report is to provide a broad historical review and commentary based on the views of the CES members, with particular emphasis on tracing the lengthy record of advisory committee recommendations. Any individual topic could be the subject of an extended report in its own right. Indeed, extensive further reviews are already under way to that end. If the CES has succeeded in the task it has undertaken. This report will serve as a useful starting point for any such more intensive study. The report is divided into eight chapters: ( I ) an introduction, (2) the evolution of the MTPE, (3) its relationship to the USGCRP, (4) applications of earth observations data, (5) the role that smaller satellites can play in research and operational remote sensing, (6) earth system modeling and information systems, (7) a number of associated activities that contribute to the MTPE

  12. Exploring short-GRB afterglow parameter space for observations in coincidence with gravitational waves

    Science.gov (United States)

    Saleem, M.; Resmi, L.; Misra, Kuntal; Pai, Archana; Arun, K. G.

    2018-03-01

    Short duration Gamma Ray Bursts (SGRB) and their afterglows are among the most promising electromagnetic (EM) counterparts of Neutron Star (NS) mergers. The afterglow emission is broad-band, visible across the entire electromagnetic window from γ-ray to radio frequencies. The flux evolution in these frequencies is sensitive to the multidimensional afterglow physical parameter space. Observations of gravitational wave (GW) from BNS mergers in spatial and temporal coincidence with SGRB and associated afterglows can provide valuable constraints on afterglow physics. We run simulations of GW-detected BNS events and assuming that all of them are associated with a GRB jet which also produces an afterglow, investigate how detections or non-detections in X-ray, optical and radio frequencies can be influenced by the parameter space. We narrow down the regions of afterglow parameter space for a uniform top-hat jet model, which would result in different detection scenarios. We list inferences which can be drawn on the physics of GRB afterglows from multimessenger astronomy with coincident GW-EM observations.

  13. NASA's Carbon Cycle OSSE Initiative - Informing future space-based observing strategies through advanced modeling and data assimilation

    Science.gov (United States)

    Ott, L.; Sellers, P. J.; Schimel, D.; Moore, B., III; O'Dell, C.; Crowell, S.; Kawa, S. R.; Pawson, S.; Chatterjee, A.; Baker, D. F.; Schuh, A. E.

    2017-12-01

    Satellite observations of carbon dioxide (CO2) and methane (CH4) are critically needed to improve understanding of the contemporary carbon budget and carbon-climate feedbacks. Though current carbon observing satellites have provided valuable data in regions not covered by surface in situ measurements, limited sampling of key regions and small but spatially coherent biases have limited the ability to estimate fluxes at the time and space scales needed for improved process-level understanding and informed decision-making. Next generation satellites will improve coverage in data sparse regions, either through use of active remote sensing, a geostationary vantage point, or increased swath width, but all techniques have limitations. The relative strengths and weaknesses of these approaches and their synergism have not previously been examined. To address these needs, a significant subset of the US carbon modeling community has come together with support from NASA to conduct a series of coordinated observing system simulation experiments (OSSEs), with close collaboration in framing the experiments and in analyzing the results. Here, we report on the initial phase of this initiative, which focused on creating realistic, physically consistent synthetic CO2 and CH4 observational datasets for use in inversion and signal detection experiments. These datasets have been created using NASA's Goddard Earth Observing System Model (GEOS) to represent the current state of atmospheric carbon as well as best available estimates of expected flux changes. Scenarios represented include changes in urban emissions, release of permafrost soil carbon, changes in carbon uptake in tropical and mid-latitude forests, changes in the Southern Ocean sink, and changes in both anthropogenic and natural methane emissions. This GEOS carbon `nature run' was sampled by instrument simulators representing the most prominent observing strategies with a focus on consistently representing the impacts of

  14. Time-Variable Gravity from Space: Quarter Century of Observations, Mysteries, and Prospects

    Science.gov (United States)

    Chao, Benjamin F.; Boy, John-Paul

    2003-01-01

    Any large mass transport in the Earth system produces changes in the gravity field. Via the space geodetic technique of satellite-laser ranging in the last quarter century, the Earth's dynamic oblateness J2 (the lowest-degree harmonic component of the gravity field) has been observed to undergo a slight decrease -- until around 1998, when it switched quite suddenly to an increase trend which has continued to 2001 before sharply turning back to the value which it is "supposed to be"!. The secular decrease in J2 has long been attributed primarily to the post-glacial rebound in the mantle; the present increase signifies an even larger change in global mass distribution whose J2 effect overshadows that of the post-glacial rebound, at least over interannual timescales. Intriguing evidences have been found in the ocean water distribution, especially in the extratropical Pacific basins, that may be responsible for this J2 change. New techniques based on satellite-to-satellite tracking will yield greatly improved observations for time-variable gravity, with much higher precision and spatial resolution (i.e., much higher harmonic degrees). The most important example is the GRACE mission launched in March 2002, following the success of the CHAMP mission. Such observations are becoming a new and powerful tool for remote sensing of geophysical fluid processes that involve larger-scale mass transports.

  15. Current problems in astrophysics needing space-based radio astronomy

    International Nuclear Information System (INIS)

    Norman, C.A.

    1987-01-01

    The potential value of space-based radio observatories and VLBI networks for studies of cosmology, AGN and starburst galaxies, the ISM and the intergalactic medium, and molecular clouds and star formation is discussed. Topics examined include distance estimates for masers in external galaxies, high-resolution 21-cm observations of distant-galaxy kinematics and morphology, searches for LF emission from the neutral ISM at redshifts higher than the QSO turnon, detection of changes in the distribution of dark matter surrounding galaxies at redshifts near 1, and observations of Galactic SNRs and filamentary structures near the Galactic center. Consideration is given to comparative studies of the ISM in the Galaxy, the Magellanic Clouds, and M 31; estimates of the molecular content of external galaxies; emssion-line studies of H 2 O masers; and kinematic investigations of bipolar flows and molecular disks. 19 references

  16. Irradiation and accretion of solids in space based on observations of lunar rocks and grains

    International Nuclear Information System (INIS)

    Lal, D.

    1977-01-01

    Clues to a wide range of questions relating to the origin and evolution of the solar system and dynamic physical and electromagnetic processes occurring concurrently and in the past in our galaxy have been provided by a study of the lunar samples. This information is deduced from a variety of complementary physical and chemical evidence. In this presentation greatest emphasis is laid on information based on effects arising from interactions of low energy cosmic rays with lunar surface materials. The present discussions concern the nature of experimental data to date and implications thereof to the charged particle environment of the Moon, ancient magnetic fields and the nature of time scales involved in the irradiation and accretion of solids in space, based on lunar regolith dynamics. It becomes clear that there does not yet exist any consensus on the absolute values of charged particle or the meteorite fluxes, and also about the details of the evolution of the lunar regolith. The complex history of evolution of lunar material is slowly being understood and it is hoped that a great deal of quantitative information will soon be available which will in turn allow discussion of evolution of solid bodies in the solar system. (author)

  17. Observational astrophysics

    CERN Document Server

    Léna, Pierre; Lebrun, François; Mignard, François; Pelat, Didier

    2012-01-01

    This is the updated, widely revised, restructured and expanded third edition of Léna et al.'s successful work Observational Astrophysics. It presents a synthesis on tools and methods of observational astrophysics of the early 21st century. Written specifically for astrophysicists and graduate students, this textbook focuses on fundamental and sometimes practical limitations on the ultimate performance that an astronomical system may reach, rather than presenting particular systems in detail. In little more than a decade there has been extraordinary progress in imaging and detection technologies, in the fields of adaptive optics, optical interferometry, in the sub-millimetre waveband, observation of neutrinos, discovery of exoplanets, to name but a few examples. The work deals with ground-based and space-based astronomy and their respective fields. And it also presents the ambitious concepts behind space missions aimed for the next decades. Avoiding particulars, it covers the whole of the electromagnetic spec...

  18. Cauchy problem for Laplace equation: An observer based approach

    KAUST Repository

    Majeed, Muhammad Usman; Zayane-Aissa, Chadia; Laleg-Kirati, Taous Meriem

    2013-01-01

    domain from the observations on outer boundary. Proposed approach adapts one of the space variables as a time variable. The observer developed to solve Cauchy problem for the Laplace's equation is compuationally robust and accurate. © 2013 IEEE.

  19. A new open-source Python-based Space Weather data access, visualization, and analysis toolkit

    Science.gov (United States)

    de Larquier, S.; Ribeiro, A.; Frissell, N. A.; Spaleta, J.; Kunduri, B.; Thomas, E. G.; Ruohoniemi, J.; Baker, J. B.

    2013-12-01

    Space weather research relies heavily on combining and comparing data from multiple observational platforms. Current frameworks exist to aggregate some of the data sources, most based on file downloads via web or ftp interfaces. Empirical models are mostly fortran based and lack interfaces with more useful scripting languages. In an effort to improve data and model access, the SuperDARN community has been developing a Python-based Space Science Data Visualization Toolkit (DaViTpy). At the center of this development was a redesign of how our data (from 30 years of SuperDARN radars) was made available. Several access solutions are now wrapped into one convenient Python interface which probes local directories, a new remote NoSQL database, and an FTP server to retrieve the requested data based on availability. Motivated by the efficiency of this interface and the inherent need for data from multiple instruments, we implemented similar modules for other space science datasets (POES, OMNI, Kp, AE...), and also included fundamental empirical models with Python interfaces to enhance data analysis (IRI, HWM, MSIS...). All these modules and more are gathered in a single convenient toolkit, which is collaboratively developed and distributed using Github and continues to grow. While still in its early stages, we expect this toolkit will facilitate multi-instrument space weather research and improve scientific productivity.

  20. Observation of Atmospheric Constituents From Space

    Science.gov (United States)

    Burrows, J. P.

    Remote sensing of the atmosphere from space is a growing research field. Surprisingly but for good physical reasons, the mesosphere and stratosphere are easier to probe from space than the troposphere. GOME (Global Ozone Monitoring Experiment) and SCIAMACHY (Scanning Imaging absorption spectroMeter for Atmospheric CHartographY) are related European instruments, which were proposed and been designed to measure atmospheric constituents (gases, aerosols and clouds) by passive remote sensing of the up-welling solar radiation leaving atmosphere. GOME is a smaller version of SCIAMACHY and was launched as part of the core payload of the second European research satellite (ERS-2) on the 20th April 1995. GOME comprises four spectral channels and measures simultaneously the earthshine radiance or solar extra terrestrial irradiance between 240 and 790 nm. Inversion of GOME measurements using the DOAS (Differential Optical Absorption Spectroscopy) yields the total column of trace gases (e.g. O3, NO2, HCHO, BrO and OClO). Application of the FURM (Full Retrieval Method) enables the profiles of O3 to be retrieved. One of the important achievements of GOME has been the separation of tropopsheirc columns of trace gases using TEM (Tropospheric Excess Method). SCIAMACHY has been developed as Germa n, Dutch and Belgian contribution to ENVISAT. It has significantly enhanced capability compared to GOME, measuring a larger spectral range, 220-2380 nm, and observing in alternate nadir and limb modes as well as solar and lunar occultation. ENVISAT is to be launched into a sun synchronous polar orbit, having an equator crossing time of 10.00 a.m. at the beginning of March 2002. SCIAMACHY is thereby able to measure many more species and vertical profiles than GOME. This facilitates improved tropospheric retrievals. Finally GeoTROPE (Geostationary TROPospheric Explorer) is a new mission, which is proposed for launch within the ESA Earth Explorer Opportunity Mission. It comprises two national

  1. Space-based observatories providing key data for climate change applications

    Science.gov (United States)

    Lecomte, J.; Juillet, J. J.

    2016-12-01

    The Sentinel-1 & 3 mission are part of the Copernicus program, previously known as GMES (Global Monitoring for Environment and Security), whose overall objective is to support Europe's goals regarding sustainable development and global governance of the environment by providing timely and quality data, information, services and knowledge. This European Earth Observation program is led by the European Commission and the space infrastructure is developed under the European Space Agency leadership. Many services will be developed through the Copernicus program among different thematic areas. The climate change is one of this thematic area and the Sentinel-1 & 3 satellites will provide key space-based observations in this area. The Sentinel-1 mission is based on a constellation of 2 identical satellites each one embarking C-SAR Instrument and provides capability for continuous radar mapping of the Earth with enhanced revisit frequency, coverage, timeliness and reliability for operational services and applications requiring long time series. In particular, Sentinel 1 provides all-weather, day-and-night estimates of soil moisture, wind speed and direction, sea ice, continental ice sheets and glaciers. The Sentinel-3 mission will mainly be devoted to the provision of Ocean observation data in routine, long term (20 years of operations) and continuous fashion with a consistent quality and a very high level of availability. Among these data, very accurate surface temperatures and topography measurements will be provided and will constitute key indicators, once ingested in climate change models, for identifying climate drivers and expected climate impacts. The paper will briefly recall the satellite architectures, their main characteristics and performance. The inflight performance and key features of their images or data of the 3 satellites namely Sentinel 1A, 1B and 3A will be reviewed to demonstrate the quality and high scientific potential of the data as well as their

  2. Probing Very Bright End of Galaxy Luminosity Function at z >~ 7 Using Hubble Space Telescope Pure Parallel Observations

    Science.gov (United States)

    Yan, Haojing; Yan, Lin; Zamojski, Michel A.; Windhorst, Rogier A.; McCarthy, Patrick J.; Fan, Xiaohui; Röttgering, Huub J. A.; Koekemoer, Anton M.; Robertson, Brant E.; Davé, Romeel; Cai, Zheng

    2011-02-01

    We report the first results from the Hubble Infrared Pure Parallel Imaging Extragalactic Survey, which utilizes the pure parallel orbits of the Hubble Space Telescope to do deep imaging along a large number of random sightlines. To date, our analysis includes 26 widely separated fields observed by the Wide Field Camera 3, which amounts to 122.8 arcmin2 in total area. We have found three bright Y 098-dropouts, which are candidate galaxies at z >~ 7.4. One of these objects shows an indication of peculiar variability and its nature is uncertain. The other two objects are among the brightest candidate galaxies at these redshifts known to date (L>2L*). Such very luminous objects could be the progenitors of the high-mass Lyman break galaxies observed at lower redshifts (up to z ~ 5). While our sample is still limited in size, it is much less subject to the uncertainty caused by "cosmic variance" than other samples because it is derived using fields along many random sightlines. We find that the existence of the brightest candidate at z ≈ 7.4 is not well explained by the current luminosity function (LF) estimates at z ≈ 8. However, its inferred surface density could be explained by the prediction from the LFs at z ≈ 7 if it belongs to the high-redshift tail of the galaxy population at z ≈ 7. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs 11700 and 11702.

  3. SPACE BASED INTERCEPTOR SCALING

    Energy Technology Data Exchange (ETDEWEB)

    G. CANAVAN

    2001-02-01

    Space Based Interceptor (SBI) have ranges that are adequate to address rogue ICBMs. They are not overly sensitive to 30-60 s delay times. Current technologies would support boost phase intercept with about 150 interceptors. Higher acceleration and velocity could reduce than number by about a factor of 3 at the cost of heavier and more expensive Kinetic Kill Vehicles (KKVs). 6g SBI would reduce optimal constellation costs by about 35%; 8g SBI would reduce them another 20%. Interceptor ranges fall rapidly with theater missile range. Constellations increase significantly for ranges under 3,000 km, even with advanced interceptor technology. For distributed launches, these estimates recover earlier strategic scalings, which demonstrate the improved absentee ratio for larger or multiple launch areas. Constellations increase with the number of missiles and the number of interceptors launched at each. The economic estimates above suggest that two SBI per missile with a modest midcourse underlay is appropriate. The SBI KKV technology would appear to be common for space- and surface-based boost phase systems, and could have synergisms with improved midcourse intercept and discrimination systems. While advanced technology could be helpful in reducing costs, particularly for short range theater missiles, current technology appears adequate for pressing rogue ICBM, accidental, and unauthorized launches.

  4. ModelLab: A Cloud-Based Platform to Support Advanced Geospatial Modeling of Earth Observation Data, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — In order to promote and facilitate broader use of NASA and other Earth observation data sources, the Phase I research focused on development of a cloud-based...

  5. First observations of tropospheric δD data observed by ground- and space-based remote sensing and surface in-situ measurement techniques at MUSICA's principle reference station (Izaña Observatory, Spain)

    Science.gov (United States)

    González, Yenny; Schneider, Matthias; Christner, Emanuel; Rodríguez, Omaira E.; Sepúlveda, Eliezer; Dyroff, Christoph; Wiegele, Andreas

    2013-04-01

    The main goal of the project MUSICA (Multiplatform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water) is the generation of a quasi global tropospheric water vapor isototopologue dataset of a good and well-documented quality. Therefore, new ground- and space-based remote sensing observations (NDACC-FTIR and IASI/METOP) are combined with in-situ measurements. This work presents the first comparison between in-situ and remote sensing observations made at the Izaña Atmospheric Research Centre (Tenerife, Canary Islands, Spain). The in-situ measurements are made by a Picarro L2120-i water vapor isotopologue analyzer. At Izaña the in-situ data are affected by local small-scale mixing processes: during daylight, the thermally buoyant upslope flow prompts the mixing between the Marine Boundary Layer (MBL) and the low Free Troposphere (FT). However, the remote sensors detect δD values averaged over altitudes that are more representative for the free troposphere. This difference has to be considered for the comparison. In general, a good agreement between the MUSICA remote sensing and the in situ H2O-versus-δD plots is found, which demonstrates that the MUSICA δD remote sensing products add scientifically valuable information to the H2O data.

  6. Precision requirements for space-based X(CO2) data

    International Nuclear Information System (INIS)

    Miller, C.E.; Crisp, D.; Miller, C.E.; Salawitch, J.; Sander, S.P.; Sen, B.; Toon, C.; DeCola, P.L.; Olsen, S.C.; Randerson, J.T.; Michalak, A.M.; Alkhaled, A.; Michalak, A.M.; Rayner, P.; Jacob, D.J.; Suntharalingam, P.; Wofsy, S.C.; Jacob, D.J.; Suntharalingam, P.; Wofsy, S.C.; Jones, D.B.A.; Denning, A.S.; Nicholls, M.E.; O'Brien, D.; Doney, S.C.; Pawson, S.; Pawson, S.; Connor, B.J.; Fung, I.Y.; Tans, P.; Wennberg, P.O.; Yung, Y.L.; Law, R.M.

    2007-01-01

    Precision requirements are determined for space-based column-averaged CO 2 dry air mole fraction X(CO 2 ) data. These requirements result from an assessment of spatial and temporal gradients in X(CO 2 ), the relationship between X(CO 2 ) precision and surface CO 2 flux uncertainties inferred from inversions of the X(CO 2 ) data, and the effects of X(CO 2 ) biases on the fidelity of CO 2 flux inversions. Observational system simulation experiments and synthesis inversion modeling demonstrate that the Orbiting Carbon Observatory mission design and sampling strategy provide the means to achieve these X(CO 2 ) data precision requirements. (authors)

  7. Movement-based Interaction in Camera Spaces

    DEFF Research Database (Denmark)

    Eriksson, Eva; Riisgaard Hansen, Thomas; Lykke-Olesen, Andreas

    2006-01-01

    In this paper we present three concepts that address movement-based interaction using camera tracking. Based on our work with several movement-based projects we present four selected applications, and use these applications to leverage our discussion, and to describe our three main concepts space......, relations, and feedback. We see these as central for describing and analysing movement-based systems using camera tracking and we show how these three concepts can be used to analyse other camera tracking applications....

  8. Lidar technologies for airborne and space-based applications

    International Nuclear Information System (INIS)

    Henson, T.D.; Schmitt, R.L.; Sobering, T.J.; Raymond, T.D.; Stephenson, D.A.

    1994-10-01

    This study identifies technologies required to extend the capabilities of airborne light detection and ranging (lidar) systems and establish the feasibility of autonomous space-based lidars. Work focused on technologies that enable the development of a lightweight, low power, rugged and autonomous Differential Absorption Lidar (DIAL) instruments. Applications for airborne or space-based DIAL include the measurement of water vapor profiles in support of climate research and processing-plant emissions signatures for environmental and nonproliferation monitoring. A computer-based lidar performance model was developed to allow trade studies to be performed on various technologies and system configurations. It combines input from the physics (absorption line strengths and locations) of the problem, the system requirements (weight, power, volume, accuracy), and the critical technologies available (detectors, lasers, filters) to produce the best conceptual design. Conceptual designs for an airborne and space-based water vapor DIAL, and a detailed design of a ground-based water vapor DIAL demonstration system were completed. Future work planned includes the final testing, integration, and operation of the demonstration system to prove the capability of the critical enabling technologies identified

  9. Atlas-based segmentation technique incorporating inter-observer delineation uncertainty for whole breast

    International Nuclear Information System (INIS)

    Bell, L R; Pogson, E M; Metcalfe, P; Holloway, L; Dowling, J A

    2017-01-01

    Accurate, efficient auto-segmentation methods are essential for the clinical efficacy of adaptive radiotherapy delivered with highly conformal techniques. Current atlas based auto-segmentation techniques are adequate in this respect, however fail to account for inter-observer variation. An atlas-based segmentation method that incorporates inter-observer variation is proposed. This method is validated for a whole breast radiotherapy cohort containing 28 CT datasets with CTVs delineated by eight observers. To optimise atlas accuracy, the cohort was divided into categories by mean body mass index and laterality, with atlas’ generated for each in a leave-one-out approach. Observer CTVs were merged and thresholded to generate an auto-segmentation model representing both inter-observer and inter-patient differences. For each category, the atlas was registered to the left-out dataset to enable propagation of the auto-segmentation from atlas space. Auto-segmentation time was recorded. The segmentation was compared to the gold-standard contour using the dice similarity coefficient (DSC) and mean absolute surface distance (MASD). Comparison with the smallest and largest CTV was also made. This atlas-based auto-segmentation method incorporating inter-observer variation was shown to be efficient (<4min) and accurate for whole breast radiotherapy, with good agreement (DSC>0.7, MASD <9.3mm) between the auto-segmented contours and CTV volumes. (paper)

  10. GROUND-BASED TRANSIT OBSERVATIONS OF THE SUPER-EARTH 55 Cnc e

    Energy Technology Data Exchange (ETDEWEB)

    De Mooij, E. J. W. [Astronomy and Astrophysics, University of Toronto, Toronto (Canada); López-Morales, M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA (United States); Karjalainen, R.; Hrudkova, M. [Isaac Newton Group of Telescopes, La Palma (Spain); Jayawardhana, Ray, E-mail: demooij@astro.utoronto.ca [Physics and Astronomy, York University, Toronto (Canada)

    2014-12-20

    We report the first ground-based detections of the shallow transit of the super-Earth exoplanet 55 Cnc e using a 2 m class telescope. Using differential spectrophotometry, we observed one transit in 2013 and another in 2014, with average spectral resolutions of ∼700 and ∼250, spanning the Johnson BVR photometric bands. We find a white light planet-to-star radius ratio of 0.0190{sub −0.0027}{sup +0.0023} from the 2013 observations and 0.0200{sub −0.0018}{sup +0.0017} from the 2014 observations. The two data sets combined result in a radius ratio of 0.0198{sub −0.0014}{sup +0.0013}. These values are all in agreement with previous space-based results. Scintillation noise in the data prevents us from placing strong constraints on the presence of an extended hydrogen-rich atmosphere. Nevertheless, our detections of 55 Cnc e in transit demonstrate that moderate-sized telescopes on the ground will be capable of routine follow-up observations of super-Earth candidates discovered by the Transiting Exoplanet Survey Satellite around bright stars. We expect it also will be possible to place constraints on the atmospheric characteristics of those planets by devising observational strategies to minimize scintillation noise.

  11. Aviation & Space Weather Policy Research: Integrating Space Weather Observations & Forecasts into Operations

    Science.gov (United States)

    Fisher, G.; Jones, B.

    2006-12-01

    The American Meteorological Society and SolarMetrics Limited are conducting a policy research project leading to recommendations that will increase the safety, reliability, and efficiency of the nation's airline operations through more effective use of space weather forecasts and information. This study, which is funded by a 3-year National Science Foundation grant, also has the support of the Federal Aviation Administration and the Joint Planning and Development Office (JPDO) who is planning the Next Generation Air Transportation System. A major component involves interviewing and bringing together key people in the aviation industry who deal with space weather information. This research also examines public and industrial strategies and plans to respond to space weather information. The focus is to examine policy issues in implementing effective application of space weather services to the management of the nation's aviation system. The results from this project will provide government and industry leaders with additional tools and information to make effective decisions with respect to investments in space weather research and services. While space weather can impact the entire aviation industry, and this project will address national and international issues, the primary focus will be on developing a U.S. perspective for the airlines.

  12. Competitive market-based allocation of consumer attention space

    NARCIS (Netherlands)

    S.M. Bohte (Sander); E.H. Gerding (Enrico); J.A. La Poutré (Han)

    2001-01-01

    textabstractThe amount of attention space available for recommending suppliers to consumers on e-commerce sites is typically limited. We present a competitive distributed recommendation mechanism based on adaptive software agents for efficiently allocating the 'consumer attention space', or banners.

  13. Space shuttle booster multi-engine base flow analysis

    Science.gov (United States)

    Tang, H. H.; Gardiner, C. R.; Anderson, W. A.; Navickas, J.

    1972-01-01

    A comprehensive review of currently available techniques pertinent to several prominent aspects of the base thermal problem of the space shuttle booster is given along with a brief review of experimental results. A tractable engineering analysis, capable of predicting the power-on base pressure, base heating, and other base thermal environmental conditions, such as base gas temperature, is presented and used for an analysis of various space shuttle booster configurations. The analysis consists of a rational combination of theoretical treatments of the prominent flow interaction phenomena in the base region. These theories consider jet mixing, plume flow, axisymmetric flow effects, base injection, recirculating flow dynamics, and various modes of heat transfer. Such effects as initial boundary layer expansion at the nozzle lip, reattachment, recompression, choked vent flow, and nonisoenergetic mixing processes are included in the analysis. A unified method was developed and programmed to numerically obtain compatible solutions for the various flow field components in both flight and ground test conditions. Preliminary prediction for a 12-engine space shuttle booster base thermal environment was obtained for a typical trajectory history. Theoretical predictions were also obtained for some clustered-engine experimental conditions. Results indicate good agreement between the data and theoretical predicitons.

  14. Space station accommodations for lunar base elements: A study

    Science.gov (United States)

    Weidman, Deene J.; Cirillo, William; Llewellyn, Charles; Kaszubowski, Martin; Kienlen, E. Michael, Jr.

    1987-01-01

    The results of a study conducted at NASA-LaRC to assess the impact on the space station of accommodating a Manned Lunar Base are documented. Included in the study are assembly activities for all infrastructure components, resupply and operations support for lunar base elements, crew activity requirements, the effect of lunar activities on Cape Kennedy operations, and the effect on space station science missions. Technology needs to prepare for such missions are also defined. Results of the study indicate that the space station can support the manned lunar base missions with the addition of a Fuel Depot Facility and a heavy lift launch vehicle to support the large launch requirements.

  15. Key techniques for space-based solar pumped semiconductor lasers

    Science.gov (United States)

    He, Yang; Xiong, Sheng-jun; Liu, Xiao-long; Han, Wei-hua

    2014-12-01

    In space, the absence of atmospheric turbulence, absorption, dispersion and aerosol factors on laser transmission. Therefore, space-based laser has important values in satellite communication, satellite attitude controlling, space debris clearing, and long distance energy transmission, etc. On the other hand, solar energy is a kind of clean and renewable resources, the average intensity of solar irradiation on the earth is 1353W/m2, and it is even higher in space. Therefore, the space-based solar pumped lasers has attracted much research in recent years, most research focuses on solar pumped solid state lasers and solar pumped fiber lasers. The two lasing principle is based on stimulated emission of the rare earth ions such as Nd, Yb, Cr. The rare earth ions absorb light only in narrow bands. This leads to inefficient absorption of the broad-band solar spectrum, and increases the system heating load, which make the system solar to laser power conversion efficiency very low. As a solar pumped semiconductor lasers could absorb all photons with energy greater than the bandgap. Thus, solar pumped semiconductor lasers could have considerably higher efficiencies than other solar pumped lasers. Besides, solar pumped semiconductor lasers has smaller volume chip, simpler structure and better heat dissipation, it can be mounted on a small satellite platform, can compose satellite array, which can greatly improve the output power of the system, and have flexible character. This paper summarizes the research progress of space-based solar pumped semiconductor lasers, analyses of the key technologies based on several application areas, including the processing of semiconductor chip, the design of small and efficient solar condenser, and the cooling system of lasers, etc. We conclude that the solar pumped vertical cavity surface-emitting semiconductor lasers will have a wide application prospects in the space.

  16. Ground and space observations of medium frequency auroral radio emissions

    Science.gov (United States)

    Broughton, Matthew C.

    The auroral zone is a rich source of natural radio emissions that can be observed in space and at ground-level. By studying these waves, scientists can gain insight into the plasma processes that generate them and use the near-Earth space environment as a large-scale plasma physics laboratory. This thesis uses both ground-level and in situ observations to study two kinds of natural radio emissions. First, we report observations of a new kind of auroral radio emission. The waves have frequencies ranging from 1.3-2.2 MHz, bandwidths ranging from 90-272 kHz, and durations ranging from 16-355 s. Spectral analysis of the waveform data has revealed that the emission has a complex combination of at least three kinds of fine structures. For model auroral electron distributions, calculations indicate that Langmuir waves could be excited at frequencies consistent with observations. The remainder of the thesis discusses auroral medium frequency (MF) burst, an impulsive, broadband natural radio emission observed at ground-level within a few minutes of local substorm onset. LaBelle [2011] proposed that MF burst originates as Langmuir/Z-mode waves on the topside of the ionosphere that subsequently mode convert to L-mode waves and propagate to ground-level. Using continuous waveform measurements and combined observations with the Sondrestrom Incoherent Scatter Radar, we have performed two tests of this mechanism. The results of these tests are consistent with the mechanism described in LaBelle [2011]. A survey of 8,624 half-orbits of the DEMETER spacecraft has revealed 68 observations of bursty MF waves. We have compared the wave properties of these waves to those of MF burst and have found that although it is uncertain, the balance of the evidence suggests that the bursty MF waves observed with DEMETER are the same phenomenon as the ground-level MF burst. Finally, we have used numerical simulations to model both the fine structure of MF burst and to estimate the attenuation the

  17. Space-Based Space Surveillance Logistics Case Study: A Qualitative Product Support Element Analysis

    Science.gov (United States)

    2017-12-01

    REPORT TYPE AND DATES COVERED Joint applied project 4. TITLE AND SUBTITLE SPACE-BASED SPACE SURVEILLANCE LOGISTICS CASE STUDY: A QUALITATIVE ...INTENTIONALLY LEFT BLANK v ABSTRACT This research provides a qualitative analysis of the logistics impacts, effects, and sustainment challenges...provides a qualitative product support element-by-element review for both research questions. Chapters IV and V present the findings, results

  18. Controls on valley spacing in landscapes subject to rapid base-level fall

    Science.gov (United States)

    McGuire, Luke; Pelletier, John D.

    2015-01-01

    What controls the architecture of drainage networks is a fundamental question in geomorphology. Recent work has elucidated the mechanisms of drainage network development in steadily uplifting landscapes, but the controls on drainage-network morphology in transient landscapes are relatively unknown. In this paper we exploit natural experiments in drainage network development in incised Plio-Quaternary alluvial fan surfaces in order to understand and quantify drainage network development in highly transient landscapes, i.e. initially unincised low-relief surfaces that experience a pulse of rapid base-level drop followed by relative base-level stasis. Parallel drainage networks formed on incised alluvial-fan surfaces tend to have a drainage spacing that is approximately proportional to the magnitude of the base-level drop. Numerical experiments suggest that this observed relationship between the magnitude of base-level drop and mean drainage spacing is the result of feedbacks among the depth of valley incision, mass wasting and nonlinear increases in the rate of colluvial sediment transport with slope gradient on steep valley side slopes that lead to increasingly wide valleys in cases of larger base-level drop. We identify a threshold magnitude of base-level drop above which side slopes lengthen sufficiently to promote increases in contributing area and fluvial incision rates that lead to branching and encourage drainage networks to transition from systems of first-order valleys to systems of higher-order, branching valleys. The headward growth of these branching tributaries prevents the development of adjacent, ephemeral drainages and promotes a higher mean valley spacing relative to cases in which tributaries do not form. Model results offer additional insights into the response of initially unincised landscapes to rapid base-level drop and provide a preliminary basis for understanding how varying amounts of base-level change influence valley network morphology.

  19. Numerical Relativity for Space-Based Gravitational Wave Astronomy

    Science.gov (United States)

    Baker, John G.

    2011-01-01

    In the next decade, gravitational wave instruments in space may provide high-precision measurements of gravitational-wave signals from strong sources, such as black holes. Currently variations on the original Laser Interferometer Space Antenna mission concepts are under study in the hope of reducing costs. Even the observations of a reduced instrument may place strong demands on numerical relativity capabilities. Possible advances in the coming years may fuel a new generation of codes ready to confront these challenges.

  20. Learning characteristics of a space-time neural network as a tether skiprope observer

    Science.gov (United States)

    Lea, Robert N.; Villarreal, James A.; Jani, Yashvant; Copeland, Charles

    1993-01-01

    The Software Technology Laboratory at the Johnson Space Center is testing a Space Time Neural Network (STNN) for observing tether oscillations present during retrieval of a tethered satellite. Proper identification of tether oscillations, known as 'skiprope' motion, is vital to safe retrieval of the tethered satellite. Our studies indicate that STNN has certain learning characteristics that must be understood properly to utilize this type of neural network for the tethered satellite problem. We present our findings on the learning characteristics including a learning rate versus momentum performance table.

  1. Campaign 9 of the K2 Mission: Observational Parameters, Scientific Drivers, and Community Involvement for a Simultaneous Space- and Ground-based Microlensing Survey

    Science.gov (United States)

    Henderson, Calen B.; Poleski, Radoslaw; Penny, Matthew; Street, Rachel A.; Bennett, David P.; Hogg, David W.; Gaudi, B. Scott; Zhu, W.; Barclay, T.; Barentsen, G.; hide

    2016-01-01

    K2's Campaign 9 (K2C9) will conduct a approximately 3.7 sq. deg survey toward the Galactic bulge from 2016 April 22 through July 2 that will leverage the spatial separation between K2 and the Earth to facilitate measurement of the microlens parallax Pi(sub E) for approximately greater than 170 microlensing events. These will include several that are planetary in nature as well as many short-timescale microlensing events, which are potentially indicative of free-floating planets (FFPs). These satellite parallax measurements will in turn allow for the direct measurement of the masses of and distances to the lensing systems. In this article we provide an overview of the K2C9 space- and ground-based microlensing survey. Specifically, we detail the demographic questions that can be addressed by this program, including the frequency of FFPs and the Galactic distribution of exoplanets, the observational parameters of K2C9, and the array of resources dedicated to concurrent observations. Finally, we outline the avenues through which the larger community can become involved, and generally encourage participation in K2C9, which constitutes an important pathfinding mission and community exercise in anticipation of WFIRST.

  2. Iterative Observer-based Estimation Algorithms for Steady-State Elliptic Partial Differential Equation Systems

    KAUST Repository

    Majeed, Muhammad Usman

    2017-07-19

    Steady-state elliptic partial differential equations (PDEs) are frequently used to model a diverse range of physical phenomena. The source and boundary data estimation problems for such PDE systems are of prime interest in various engineering disciplines including biomedical engineering, mechanics of materials and earth sciences. Almost all existing solution strategies for such problems can be broadly classified as optimization-based techniques, which are computationally heavy especially when the problems are formulated on higher dimensional space domains. However, in this dissertation, feedback based state estimation algorithms, known as state observers, are developed to solve such steady-state problems using one of the space variables as time-like. In this regard, first, an iterative observer algorithm is developed that sweeps over regular-shaped domains and solves boundary estimation problems for steady-state Laplace equation. It is well-known that source and boundary estimation problems for the elliptic PDEs are highly sensitive to noise in the data. For this, an optimal iterative observer algorithm, which is a robust counterpart of the iterative observer, is presented to tackle the ill-posedness due to noise. The iterative observer algorithm and the optimal iterative algorithm are then used to solve source localization and estimation problems for Poisson equation for noise-free and noisy data cases respectively. Next, a divide and conquer approach is developed for three-dimensional domains with two congruent parallel surfaces to solve the boundary and the source data estimation problems for the steady-state Laplace and Poisson kind of systems respectively. Theoretical results are shown using a functional analysis framework, and consistent numerical simulation results are presented for several test cases using finite difference discretization schemes.

  3. Results from Joint Observations of Jupiter's Atmosphere by Juno and a Network of Earth-Based Observing Stations

    Science.gov (United States)

    Orton, G. S.; Bolton, S. J.; Levin, S.; Hansen, C. J.; Janssen, M. A.; Adriani, A.; Gladstone, R.; Bagenal, F.; Ingersoll, A. P.; Momary, T.; Payne, A.

    2016-12-01

    The Juno mission has promoted and coordinated a network of Earth-based observations, including both space- and ground-based facilities, to extend and enhance observations made by the Juno mission. The spectral region and timeline of all of these observations are summarized in the web site: https://www.missionjuno.swri.edu/planned-observations. Among the earliest of these were observation of Jovian auroral phenomena at X-ray, ultraviolet and infrared wavelengths and measurements of Jovian synchrotron radiation from the Earth simultaneously with the measurement of properties of the upstream solar wind described elsewhere in this meeting. Other observations of significance to the magnetosphere measured the mass loading from Io by tracking its observed volcanic activity and the opacity of its torus. Observations of Jupiter's neutral atmosphere included observations of reflected sunlight from the near-ultraviolet through the near-infrared and thermal emission from 5 microns through the radio region. The point of these measurements is to relate properties of the deep atmosphere that are the focus of Juno's mission to the state of the "weather layer" at much higher atmospheric levels. These observations cover spectral regions not included in Juno's instrumentation, provide spatial context for Juno's often spatially limited coverage of Jupiter, and they describe the evolution of atmospheric features in time that are measured only once by Juno. We will summarize the results of measurements during the approach phase of the mission that characterized the state of the atmosphere, as well as observations made by Juno and the supporting campaign during Juno's perijoves 1 (August 27), 2 (October 19), 3 (November 2), 4 (November 15), and 5 (November 30). The Juno mission also benefited from the enlistment of a network of dedicated amateur astronomers who, besides providing input needed for public operation of the JunoCam visible camera, tracked the evolution of features in Jupiter

  4. CIMEX: a prototype Instrument to observe from space the amazon forest In the near and shortwave infrared

    Science.gov (United States)

    Guerin, François; Dantes, Didier; Savaria, Eric; Selingardi, Mario Luis; Montes, Amauri Silva

    2018-04-01

    This paper, "CIMEX: a prototype Instrument to observe from space the amazon forest In the near and shortwave infrared," was presented as part of International Conference on Space Optics—ICSO 1997, held in Toulouse, France.

  5. Physics-based Space Weather Forecasting in the Project for Solar-Terrestrial Environment Prediction (PSTEP) in Japan

    Science.gov (United States)

    Kusano, K.

    2016-12-01

    Project for Solar-Terrestrial Environment Prediction (PSTEP) is a Japanese nation-wide research collaboration, which was recently launched. PSTEP aims to develop a synergistic interaction between predictive and scientific studies of the solar-terrestrial environment and to establish the basis for next-generation space weather forecasting using the state-of-the-art observation systems and the physics-based models. For this project, we coordinate the four research groups, which develop (1) the integration of space weather forecast system, (2) the physics-based solar storm prediction, (3) the predictive models of magnetosphere and ionosphere dynamics, and (4) the model of solar cycle activity and its impact on climate, respectively. In this project, we will build the coordinated physics-based model to answer the fundamental questions concerning the onset of solar eruptions and the mechanism for radiation belt dynamics in the Earth's magnetosphere. In this paper, we will show the strategy of PSTEP, and discuss about the role and prospect of the physics-based space weather forecasting system being developed by PSTEP.

  6. A state-space-based prognostics model for lithium-ion battery degradation

    International Nuclear Information System (INIS)

    Xu, Xin; Chen, Nan

    2017-01-01

    This paper proposes to analyze the degradation of lithium-ion batteries with the sequentially observed discharging profiles. A general state-space model is developed in which the observation model is used to approximate the discharging profile of each cycle, the corresponding parameter vector is treated as the hidden state, and the state-transition model is used to track the evolution of the parameter vector as the battery ages. The EM and EKF algorithms are adopted to estimate and update the model parameters and states jointly. Based on this model, we construct prediction on the end of discharge times for unobserved cycles and the remaining useful cycles before the battery failure. The effectiveness of the proposed model is demonstrated using a real lithium-ion battery degradation data set. - Highlights: • Unifying model for Li-Ion battery SOC and SOH estimation. • Extended Kalman filter based efficient inference algorithm. • Using voltage curves in discharging to have wide validity.

  7. Hubble space telescope: The GO and GTO observing programs, version 3.0

    Science.gov (United States)

    Downes, Ron

    1992-01-01

    A portion of the observing time with the Hubble Space Telescope (HST) was awarded by NASA to scientists involved in the development of the HST and its instruments. These scientists are the Guaranteed Time Observers (GTO's). Observing time was also awarded to General Observers (GO's) on the basis of the proposal reviews in 1989 and 1991. The majority of the 1989 programs have been completed during 'Cycle 1', while the 1991 programs will be completed during 'Cycle 2', nominally a 12-month period beginning July 1992. This document presents abstracts of these GO and GTO programs, and detailed listings of the specific targets and exposures contained in them. These programs and exposures are protected by NASA policy, as detailed in the HST Call for Proposals (CP), and are not to be duplicated by new programs.

  8. Large micro-mirror arrays: key components in future space instruments for Universe and Earth Observation

    Directory of Open Access Journals (Sweden)

    Zamkotsian Frederic

    2015-01-01

    Full Text Available In future space missions for Universe and Earth Observation, scientific return could be optimized using MOEMS devices. Micro-mirror arrays are used for designing new generation of instruments, multi-object spectrographs in Universe Observation and programmable wide field spectrographs in Earth Observation. Mock-ups have been designed and built for both applications and they show very promising results.

  9. Micro-satellite for space debris observation by optical sensors

    Science.gov (United States)

    Thillot, Marc; Brenière, Xavier; Midavaine, Thierry

    2017-11-01

    The purpose of this theoretical study carried out under CNES contract is to analyze the feasibility of small space debris detection and classification with an optical sensor on-board micro-satellite. Technical solutions based on active and passive sensors are analyzed and compared. For the most appropriated concept an optimization was made and theoretical performances in terms of number of detection versus class of diameter were calculated. Finally we give some preliminary physical sensor features to illustrate the concept (weight, volume, consumption,…).

  10. Dynamics of macro-observables and space-time inhomogeneous Gibbs ensembles

    International Nuclear Information System (INIS)

    Lanz, L.; Lupieri, G.

    1978-01-01

    The relationship between the classical description of a macro-system and quantum mechanics of its particles is considered within the framework recently developed by Ludwig. A procedure is given to define probability measures on the trajectory space of a macrosystem which yields a statistical description of the dynamics of a macrosystem. The basic tool in this treatment is a new concept of space-time inhomogeneous Gibbs ensemble, defined in N-body quantum mechanics. In the Gaussian approximation of the probabilities the results of Zubarev's theory based on the ''nonequilibrium statistical operator'' are recovered. The present ''embedding'' of the description of a macrosystem inside the N-body theory allows for a joint description of a macrosystem and a microsubsystem of it, and a ''macroscopical'' calculation of the statistical operator of the microsystem is indicated. (author)

  11. Why advanced computing? The key to space-based operations

    Science.gov (United States)

    Phister, Paul W., Jr.; Plonisch, Igor; Mineo, Jack

    2000-11-01

    The 'what is the requirement?' aspect of advanced computing and how it relates to and supports Air Force space-based operations is a key issue. In support of the Air Force Space Command's five major mission areas (space control, force enhancement, force applications, space support and mission support), two-fifths of the requirements have associated stringent computing/size implications. The Air Force Research Laboratory's 'migration to space' concept will eventually shift Science and Technology (S&T) dollars from predominantly airborne systems to airborne-and-space related S&T areas. One challenging 'space' area is in the development of sophisticated on-board computing processes for the next generation smaller, cheaper satellite systems. These new space systems (called microsats or nanosats) could be as small as a softball, yet perform functions that are currently being done by large, vulnerable ground-based assets. The Joint Battlespace Infosphere (JBI) concept will be used to manage the overall process of space applications coupled with advancements in computing. The JBI can be defined as a globally interoperable information 'space' which aggregates, integrates, fuses, and intelligently disseminates all relevant battlespace knowledge to support effective decision-making at all echelons of a Joint Task Force (JTF). This paper explores a single theme -- on-board processing is the best avenue to take advantage of advancements in high-performance computing, high-density memories, communications, and re-programmable architecture technologies. The goal is to break away from 'no changes after launch' design to a more flexible design environment that can take advantage of changing space requirements and needs while the space vehicle is 'on orbit.'

  12. Design and implementation of space physics multi-model application integration based on web

    Science.gov (United States)

    Jiang, Wenping; Zou, Ziming

    With the development of research on space environment and space science, how to develop network online computing environment of space weather, space environment and space physics models for Chinese scientific community is becoming more and more important in recent years. Currently, There are two software modes on space physics multi-model application integrated system (SPMAIS) such as C/S and B/S. the C/S mode which is traditional and stand-alone, demands a team or workshop from many disciplines and specialties to build their own multi-model application integrated system, that requires the client must be deployed in different physical regions when user visits the integrated system. Thus, this requirement brings two shortcomings: reducing the efficiency of researchers who use the models to compute; inconvenience of accessing the data. Therefore, it is necessary to create a shared network resource access environment which could help users to visit the computing resources of space physics models through the terminal quickly for conducting space science research and forecasting spatial environment. The SPMAIS develops high-performance, first-principles in B/S mode based on computational models of the space environment and uses these models to predict "Space Weather", to understand space mission data and to further our understanding of the solar system. the main goal of space physics multi-model application integration system (SPMAIS) is to provide an easily and convenient user-driven online models operating environment. up to now, the SPMAIS have contained dozens of space environment models , including international AP8/AE8 IGRF T96 models and solar proton prediction model geomagnetic transmission model etc. which are developed by Chinese scientists. another function of SPMAIS is to integrate space observation data sets which offers input data for models online high-speed computing. In this paper, service-oriented architecture (SOA) concept that divides system into

  13. Hubble Space Telescope Wide Field Planetary Camera 2 Observations of Neptune

    Science.gov (United States)

    1995-01-01

    Two groups have recently used the Hubble Space Telescope (HST) Wide Field Planetary Camera 2 (WFPC 2) to acquire new high-resolution images of the planet Neptune. Members of the WFPC-2 Science Team, lead by John Trauger, acquired the first series of images on 27 through 29 June 1994. These were the highest resolution images of Neptune taken since the Voyager-2 flyby in August of 1989. A more comprehensive program is currently being conducted by Heidi Hammel and Wes Lockwood. These two sets of observations are providing a wealth of new information about the structure, composition, and meteorology of this distant planet's atmosphere.Neptune is currently the most distant planet from the sun, with an orbital radius of 4.5 billion kilometers (2.8 billion miles, or 30 Astronomical Units). Even though its diameter is about four times that of the Earth (49,420 vs. 12,742 km), ground-based telescopes reveal a tiny blue disk that subtends less than 1/1200 of a degree (2.3 arc-seconds). Neptune has therefore been a particularly challenging object to study from the ground because its disk is badly blurred by the Earth's atmosphere. In spite of this, ground-based astronomers had learned a great deal about this planet since its position was first predicted by John C. Adams and Urbain Leverrier in 1845. For example, they had determined that Neptune was composed primarily of hydrogen and helium gas, and that its blue color caused by the presence of trace amounts of the gas methane, which absorbs red light. They had also detected bright cloud features whose brightness changed with time, and tracked these clouds to infer a rotation period between 17 and 22 hours.When the Voyager-2 spacecraft flew past the Neptune in 1989, its instruments revealed a surprising array of meteorological phenomena, including strong winds, bright, high-altitude clouds, and two large dark spots attributed to long-lived giant storm systems. These bright clouds and dark spots were tracked as they moved

  14. Simulations of VLBI observations of a geodetic satellite providing co-location in space

    Science.gov (United States)

    Anderson, James M.; Beyerle, Georg; Glaser, Susanne; Liu, Li; Männel, Benjamin; Nilsson, Tobias; Heinkelmann, Robert; Schuh, Harald

    2018-02-01

    We performed Monte Carlo simulations of very-long-baseline interferometry (VLBI) observations of Earth-orbiting satellites incorporating co-located space-geodetic instruments in order to study how well the VLBI frame and the spacecraft frame can be tied using such measurements. We simulated observations of spacecraft by VLBI observations, time-of-flight (TOF) measurements using a time-encoded signal in the spacecraft transmission, similar in concept to precise point positioning, and differential VLBI (D-VLBI) observations using angularly nearby quasar calibrators to compare their relative performance. We used the proposed European Geodetic Reference Antenna in Space (E-GRASP) mission as an initial test case for our software. We found that the standard VLBI technique is limited, in part, by the present lack of knowledge of the absolute offset of VLBI time to Coordinated Universal Time at the level of microseconds. TOF measurements are better able to overcome this problem and provide frame ties with uncertainties in translation and scale nearly a factor of three smaller than those yielded from VLBI measurements. If the absolute time offset issue can be resolved by external means, the VLBI results can be significantly improved and can come close to providing 1 mm accuracy in the frame tie parameters. D-VLBI observations with optimum performance assumptions provide roughly a factor of two higher uncertainties for the E-GRASP orbit. We additionally simulated how station and spacecraft position offsets affect the frame tie performance.

  15. Conserving Space Heritage - The Case for Tranquillity Base

    Science.gov (United States)

    Fewer, G.

    One of the most important and spectacular events in the history of space exploration was the first Moon Landing of 1969. Safe from the ravages of erosion, agriculture, industry or the expansion of human settlement, the greatest threat to the site of this momentous event - Tranquillity Base - is likely to be from a meteor impact. However, with the advent of space tourism and commercial space travel, the site of humankind's first visit to a celestial body may come under threat of a different kind - that of souvenir hunters and miners. In this paper, the historical background to the Apollo programme is outlined and the sequence of events that made up the Apollo 11 mission, which conducted the first Moon landing, is described before concluding with a consideration of the heritage conservation issues of Tranquillity Base.

  16. Ground-Based Global Navigation Satellite System (GNSS) Compact Observation Data (1-second sampling, sub-hourly files) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset consists of ground-based Global Navigation Satellite System (GNSS) Observation Data (1-second sampling, sub-hourly files) from the NASA Crustal Dynamics...

  17. On the possibility of space objects invasion observations into the Earth's atmosphere with the help of a multifunctional polarimeter

    Science.gov (United States)

    Nevodovskyi, P. V.; Steklov, A. F.; Vidmachenko, A. P.

    2018-05-01

    Relevance of the tasks associated with the observation of the invasion of space objects into the Earth's atmosphere increases with each passing year. We used astronomical panoramic polarimeter for carrying out of polarimetric observations of objects, that flying into the atmosphere of the Earth from the surrounding outer space.

  18. Space-based ballistic-missile defense

    International Nuclear Information System (INIS)

    Bethe, H.A.; Garwin, R.L.; Gottfried, K.; Kendall, H.W.

    1984-01-01

    This article, based on a forthcoming book by the Union for Concerned Scientists, focuses on the technical aspects of the issue of space-based ballistic-missile defense. After analysis, the authors conclude that the questionable performance of the proposed defense, the ease with which it could be overwhelmed or circumvented, and its potential as an antisatellite system would cause grievous damage to the security of the US if the Strategic Defense Initiative were to be pursued. The path toward greater security lies in quite another direction, they feel. Although research on ballistic-missile defense should continue at the traditional level of expenditure and within the constraints of the ABM Treaty, every effort should be made to negotiate a bilateral ban on the testing and use of space weapons. The authors think it is essential that such an agreement cover all altitudes, because a ban on high-altitude antisatellite weapons alone would not viable if directed energy weapons were developed for ballistic-missile defense. Further, the Star Wars program, unlikely ever to protect the entire nation against a nuclear attack, would nonetheless trigger a major expansion of the arms race

  19. State space modeling of Memristor-based Wien oscillator

    KAUST Repository

    Talukdar, Abdul Hafiz Ibne; Radwan, Ahmed G.; Salama, Khaled N.

    2011-01-01

    State space modeling of Memristor based Wien 'A' oscillator has been demonstrated for the first time considering nonlinear ion drift in Memristor. Time dependant oscillating resistance of Memristor is reported in both state space solution and SPICE simulation which plausibly provide the basis of realizing parametric oscillation by Memristor based Wien oscillator. In addition to this part Memristor is shown to stabilize the final oscillation amplitude by means of its nonlinear dynamic resistance which hints for eliminating diode in the feedback network of conventional Wien oscillator. © 2011 IEEE.

  20. State space modeling of Memristor-based Wien oscillator

    KAUST Repository

    Talukdar, Abdul Hafiz Ibne

    2011-12-01

    State space modeling of Memristor based Wien \\'A\\' oscillator has been demonstrated for the first time considering nonlinear ion drift in Memristor. Time dependant oscillating resistance of Memristor is reported in both state space solution and SPICE simulation which plausibly provide the basis of realizing parametric oscillation by Memristor based Wien oscillator. In addition to this part Memristor is shown to stabilize the final oscillation amplitude by means of its nonlinear dynamic resistance which hints for eliminating diode in the feedback network of conventional Wien oscillator. © 2011 IEEE.

  1. Spectroscopic characterization of extrasolar planets from ground-, space- and airborne-based observatories

    Science.gov (United States)

    Angerhausen, Daniel

    2010-11-01

    This thesis deals with techniques and results of observations of exoplanets from several platforms. In this work I present and then attempt solutions to particular issues and problems connected to ground- and space-based approaches to spectroscopic characterization of extrasolar planets. Furthermore, I present the future prospects of the airborne observatory, SOFIA, in this field of astronomy. The first part of this thesis covers results of an exploratory study to use near-infrared integral-field-spectroscopy to observe transiting extrasolar planets. I demonstrate how adaptive-optics assisted integral field spectroscopy compares with other spectroscopic techniques currently applied, foremost being slit spectroscopy. An advanced reduction method using elements of a spectral-differential decorrelation and optimized observation strategies is discussed. This concept was tested with K-Band time series observations of secondary eclipses of HD 209458b and HD 189733b obtained with the SINFONI at the Very Large Telescope (VLT), at spectral resolution of R~3000. In ground-based near infrared (NIR) observations, there is considerable likelihood of confusion between telluric absorption features and spectral features in the targeted object. I describe a detailed method that can cope with such confusion by a forward modelling approach employing Earth transmission models. In space-based transit spectroscopy with Hubble's NICMOS instrument, the main source of systematic noise is the perturbation in the instrument's configuration due to the near Earth orbital motion of the spacecraft. I present an extension to a pre-existing data analysis sequence that has allowed me to extract a NIR transmission spectrum of the hot-Neptune class planet GJ 436b from a data set that was highly corrupted by the above mentioned effects. Satisfyingly, I was able to obtain statistical consistency in spectra (acquired over a broad wavelength grid) over two distinct observing visits by HST. Earlier

  2. A new technique for observationally derived boundary conditions for space weather

    Science.gov (United States)

    Pagano, Paolo; Mackay, Duncan Hendry; Yeates, Anthony Robinson

    2018-04-01

    Context. In recent years, space weather research has focused on developing modelling techniques to predict the arrival time and properties of coronal mass ejections (CMEs) at the Earth. The aim of this paper is to propose a new modelling technique suitable for the next generation of Space Weather predictive tools that is both efficient and accurate. The aim of the new approach is to provide interplanetary space weather forecasting models with accurate time dependent boundary conditions of erupting magnetic flux ropes in the upper solar corona. Methods: To produce boundary conditions, we couple two different modelling techniques, MHD simulations and a quasi-static non-potential evolution model. Both are applied on a spatial domain that covers the entire solar surface, although they extend over a different radial distance. The non-potential model uses a time series of observed synoptic magnetograms to drive the non-potential quasi-static evolution of the coronal magnetic field. This allows us to follow the formation and loss of equilibrium of magnetic flux ropes. Following this a MHD simulation captures the dynamic evolution of the erupting flux rope, when it is ejected into interplanetary space. Results.The present paper focuses on the MHD simulations that follow the ejection of magnetic flux ropes to 4 R⊙. We first propose a technique for specifying the pre-eruptive plasma properties in the corona. Next, time dependent MHD simulations describe the ejection of two magnetic flux ropes, that produce time dependent boundary conditions for the magnetic field and plasma at 4 R⊙ that in future may be applied to interplanetary space weather prediction models. Conclusions: In the present paper, we show that the dual use of quasi-static non-potential magnetic field simulations and full time dependent MHD simulations can produce realistic inhomogeneous boundary conditions for space weather forecasting tools. Before a fully operational model can be produced there are a

  3. Observations of interplanetary scintillation and their application to the space weather forecast

    International Nuclear Information System (INIS)

    Kojima, Masayoshi; Kakinuma, Takakiyo

    1989-01-01

    The interplanetary scintillation (IPS) method using natural radio sources can observe the solar wind near the sun and at high latitudes that have never been accessible to any spacecraft. Therefore, the IPS has been the most powerful method to observe the solar wind in three-dimensional space. Although the IPS method cannot predict when a flare will occur or when a filament will disappear, it can be used to forecast the propagation of interplanetary disturbances and to warn when they will attack the earth. Thus, the IPS method can be used to forecast recurrent interplanetary phenomena as well as transient phenomena. (author)

  4. CONFRONTING THREE-DIMENSIONAL TIME-DEPENDENT JET SIMULATIONS WITH HUBBLE SPACE TELESCOPE OBSERVATIONS

    International Nuclear Information System (INIS)

    Staff, Jan E.; Niebergal, Brian P.; Ouyed, Rachid; Pudritz, Ralph E.; Cai, Kai

    2010-01-01

    We perform state-of-the-art, three-dimensional, time-dependent simulations of magnetized disk winds, carried out to simulation scales of 60 AU, in order to confront optical Hubble Space Telescope observations of protostellar jets. We 'observe' the optical forbidden line emission produced by shocks within our simulated jets and compare these with actual observations. Our simulations reproduce the rich structure of time-varying jets, including jet rotation far from the source, an inner (up to 400 km s -1 ) and outer (less than 100 km s -1 ) component of the jet, and jet widths of up to 20 AU in agreement with observed jets. These simulations when compared with the data are able to constrain disk wind models. In particular, models featuring a disk magnetic field with a modest radial spatial variation across the disk are favored.

  5. Trigonometric bases for matrix weighted Lp-spaces

    DEFF Research Database (Denmark)

    Nielsen, Morten

    2010-01-01

    We give a complete characterization of 2π-periodic matrix weights W for which the vector-valued trigonometric system forms a Schauder basis for the matrix weighted space Lp(T;W). Then trigonometric quasi-greedy bases for Lp(T;W) are considered. Quasi-greedy bases are systems for which the simple...

  6. Activities of NICT space weather project

    Science.gov (United States)

    Murata, Ken T.; Nagatsuma, Tsutomu; Watari, Shinichi; Shinagawa, Hiroyuki; Ishii, Mamoru

    NICT (National Institute of Information and Communications Technology) has been in charge of space weather forecast service in Japan for more than 20 years. The main target region of the space weather is the geo-space in the vicinity of the Earth where human activities are dominant. In the geo-space, serious damages of satellites, international space stations and astronauts take place caused by energetic particles or electromagnetic disturbances: the origin of the causes is dynamically changing of solar activities. Positioning systems via GPS satellites are also im-portant recently. Since the most significant effect of positioning error comes from disturbances of the ionosphere, it is crucial to estimate time-dependent modulation of the electron density profiles in the ionosphere. NICT is one of the 13 members of the ISES (International Space Environment Service), which is an international assembly of space weather forecast centers under the UNESCO. With help of geo-space environment data exchanging among the member nations, NICT operates daily space weather forecast service every day to provide informa-tion on forecasts of solar flare, geomagnetic disturbances, solar proton event, and radio-wave propagation conditions in the ionosphere. The space weather forecast at NICT is conducted based on the three methodologies: observations, simulations and informatics (OSI model). For real-time or quasi real-time reporting of space weather, we conduct our original observations: Hiraiso solar observatory to monitor the solar activity (solar flare, coronal mass ejection, and so on), domestic ionosonde network, magnetometer HF radar observations in far-east Siberia, and south-east Asia low-latitude ionosonde network (SEALION). Real-time observation data to monitor solar and solar-wind activities are obtained through antennae at NICT from ACE and STEREO satellites. We have a middle-class super-computer (NEC SX-8R) to maintain real-time computer simulations for solar and solar

  7. High Fidelity Airborne Imaging System for Remote Observation of Space Launch/Reentry Systems, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The utility of airborne remote observation of hypersonic reentry vehicles was demonstrated by the NASA Hypersonic Thermodynamic Infrared Measurement (HYTHIRM)...

  8. Earth-based Observing Campaign For Comet 103p/hartley 2 For The Dixi Mission

    Science.gov (United States)

    Meech, Karen Jean; Kelley, M. S.; A'Hearn, M. F.; DIXI Observing Team

    2011-01-01

    The Deep Impact Extended mission (DIXI) is part of the EPOXI mission and will rendezvous with the comet 103P/Hartley 2 on 4 Nov. 2010 at 13:50 UT. Many of the anticipated key science results will come from the combined interpretation of the in-situ spacecraft data and the Earth- and space-based observing campaigns. DIXI in-situ objectives include characterizing the nucleus properties, understanding the activity (outbursts, and sources), mapping the surface and correlating surface albedo, color and temperature with topography to understand the thermal properties of the surface. The Earth-based observations provide a longer-term context for the in-situ observations, and will characterize the activity levels leading up to the encounter, including assessing the dust environment and volatile species production rates. Earth-based observations will search for outbursts and jets that might be linked to activity. The international observing campaign scheduled at more than 20 observatories, began in March 2010, and will continue beyond January 2011, although selected observations began in 2008 with the recovery of the nucleus (Snodgrass et al., (2010), A&A, 516L) and Spitzer IR observations (Lisse et al., (2009) PASP 121, 968), and in 2009 with the measurement of the rotational light curve. We will report on Earth-based observing highlights and their synergies with the in-situ observations. With these combined data we can not only better understand comet Hartley 2, but through the legacy of telescopic observations we may also better understand comets as a whole.

  9. Space shuttle main engine vibration data base

    Science.gov (United States)

    Lewallen, Pat

    1986-01-01

    The Space Shuttle Main Engine Vibration Data Base is described. Included is a detailed description of the data base components, the data acquisition process, the more sophisticated software routines, and the future data acquisition methods. Several figures and plots are provided to illustrate the various output formats accessible to the user. The numerous vibration data recall and analysis capabilities available through automated data base techniques are revealed.

  10. Space weather in the EU’s FP7 Space Theme

    Directory of Open Access Journals (Sweden)

    Chiarini Paola

    2013-11-01

    Full Text Available Technological infrastructures in space and on ground provide services on which modern society and economies rely. Space weather related research is funded under the 7th Framework Programme for Research and Innovation (FP7 of the European Union in response to the need of protecting such critical infrastructures from the damage which could be caused by extreme space weather events. The calls for proposals published under the topic “Security of space assets from space weather events” of the FP7 Space Theme aimed to improve forecasts and predictions of disruptive space weather events as well as identify best practices to limit the impacts on space- and ground-based infrastructures and their data provision. Space weather related work was also funded under the topic “Exploitation of space science and exploration data”, which aims to add value to space missions and Earth-based observations by contributing to the effective scientific exploitation of collected data. Since 2007 a total of 20 collaborative projects have been funded, covering a variety of physical phenomena associated with space weather, from ionospheric disturbances and scintillation, to geomagnetically induced currents at Earth’s surface, to coronal mass ejections and solar energetic particles. This article provides an overview of the funded projects, touching upon some results and referring to specific websites for a more exhaustive description of the projects’ outcomes.

  11. Operation of a Data Acquisition, Transfer, and Storage System for the Global Space-Weather Observation Network

    Directory of Open Access Journals (Sweden)

    T Nagatsuma

    2014-10-01

    Full Text Available A system to optimize the management of global space-weather observation networks has been developed by the National Institute of Information and Communications Technology (NICT. Named the WONM (Wide-area Observation Network Monitoring system, it enables data acquisition, transfer, and storage through connection to the NICT Science Cloud, and has been supplied to observatories for supporting space-weather forecast and research. This system provides us with easier management of data collection than our previously employed systems by means of autonomous system recovery, periodical state monitoring, and dynamic warning procedures. Operation of the WONM system is introduced in this report.

  12. Space Launch System Base Heating Test: Tunable Diode Laser Absorption Spectroscopy

    Science.gov (United States)

    Parker, Ron; Carr, Zak; MacLean, Mathew; Dufrene, Aaron; Mehta, Manish

    2016-01-01

    This paper describes the Tunable Diode Laser Absorption Spectroscopy (TDLAS) measurement of several water transitions that were interrogated during a hot-fire testing of the Space Launch Systems (SLS) sub-scale vehicle installed in LENS II. The temperature of the recirculating gas flow over the base plate was found to increase with altitude and is consistent with CFD results. It was also observed that the gas above the base plate has significant velocity along the optical path of the sensor at the higher altitudes. The line-by-line analysis of the H2O absorption features must include the effects of the Doppler shift phenomena particularly at high altitude. The TDLAS experimental measurements and the analysis procedure which incorporates the velocity dependent flow will be described.

  13. Optimal Time-Space Trade-Offs for Non-Comparison-Based Sorting

    DEFF Research Database (Denmark)

    Pagh, Rasmus; Pagter, Jacob Illeborg

    2002-01-01

    We study the problem of sorting n integers of w bits on a unit-cost RAM with word size w, and in particular consider the time-space trade-off (product of time and space in bits) for this problem. For comparison-based algorithms, the time-space complexity is known to be Θ(n2). A result of Beame...... shows that the lower bound also holds for non-comparison-based algorithms, but no algorithm has met this for time below the comparison-based Ω(nlgn) lower bound.We show that if sorting within some time bound &Ttilde; is possible, then time T = O(&Ttilde; + nlg* n) can be achieved with high probability...... using space S = O(n2/T + w), which is optimal. Given a deterministic priority queue using amortized time t(n) per operation and space nO(1), we provide a deterministic algorithm sorting in time T = O(n(t(n) + lg* n)) with S = O(n2/T + w). Both results require that w ≤ n1-Ω(1). Using existing priority...

  14. An Inverse Source Problem for a One-dimensional Wave Equation: An Observer-Based Approach

    KAUST Repository

    Asiri, Sharefa M.

    2013-05-25

    Observers are well known in the theory of dynamical systems. They are used to estimate the states of a system from some measurements. However, recently observers have also been developed to estimate some unknowns for systems governed by Partial differential equations. Our aim is to design an observer to solve inverse source problem for a one dimensional wave equation. Firstly, the problem is discretized in both space and time and then an adaptive observer based on partial field measurements (i.e measurements taken form the solution of the wave equation) is applied to estimate both the states and the source. We see the effectiveness of this observer in both noise-free and noisy cases. In each case, numerical simulations are provided to illustrate the effectiveness of this approach. Finally, we compare the performance of the observer approach with Tikhonov regularization approach.

  15. Design Optimization for Interferometric Space-Based 21-cm Power Spectrum Measurements

    Science.gov (United States)

    Pober, Jonathan

    2018-06-01

    Observations of the highly-redshifted 21 cm hyperfine line of neutral hydrogen (HI) are one of the most promising probes for the future of cosmology. At redshifts z > 30, the HI signal is likely the only measurable emission, as luminous objects have yet to form. At these very low radio frequencies, however, the earth’s ionosphere becomes opaque — necessitating observations from space. The major challenge to neutral hydrogen cosmology (at all redshifts) lies in the presence of bright foreground emission, which can dominate the HI signal by as much as eight orders of magnitude at the highest redshifts. The only method for extracting the cosmological signal relies on the spectral smoothness of the foregrounds; since each frequency of the HI signal probes a different redshift, the cosmological emission is essentially uncorrelated from frequency to frequency. The key challenge for designing an experiment lies in maintaining the spectral smoothness of the foregrounds. If the frequency response of the instrument introduces spectral structure (or at least, a residual that cannot be calibrated out at the necessary precision), it quickly becomes impossible to distinguish the cosmological signal from the foregrounds. This principle has guided the design of ground-based experiments like the Precision Array for Probing the Epoch of Reionization (PAPER) and the Hydrogen Epoch of Reionization Array (HERA). However, there still exists no unifying framework for turning this design "philosophy" into a robust, quantitative set of performance metrics and specifications. In this talk, I will present updates on the efforts of my research group to translate lessons learned from ground-based experiments into a fully traceable set of mission requirements for Cosmic Dawn Mapper or other space-based 21 cm interferometer.

  16. Observational astrophysics.

    Science.gov (United States)

    Léna, P.; Lebrun, F.; Mignard, F.

    This book is the 2nd edition of an English translation published in 1988 (45.003.105) of the French original "Astrophysique: Méthodes physiques de l'observation" published in 1986 (42.003.048). Written specifically for physicists and graduate students in astronomy, this textbook focuses on astronomical observation and on the basic physical principles that astronomers use to conceive, build and exploit their instruments at their ultimate limits in sensitivity or resolution. This second edition has been entirely restructured and almost doubled in size, in order to improve its clarity and to account for the great progress achieved in the last 15 years. It deals with ground-based and space-based astronomy and their respective fields. It presents the new generation of giant ground-based telescopes, with the new methods of optical interferometry and adaptive optics, and also the ambitious concepts behind planned space missions for the next decades. Avoiding particulars, it covers the whole of the electromagnetic spectrum and touches upon the "new astronomies" becoming possible with gravitational waves and neutrinos.

  17. Measuring the Microlensing Parallax from Various Space Observatories

    Science.gov (United States)

    Bachelet, E.; Hinse, T. C.; Street, R.

    2018-05-01

    A few observational methods allow the measurement of the mass and distance of the lens-star for a microlensing event. A first estimate can be obtained by measuring the microlensing parallax effect produced by either the motion of the Earth (annual parallax) or the contemporaneous observation of the lensing event from two (or more) observatories (space or terrestrial parallax) sufficiently separated from each other. Further developing ideas originally outlined by Gould as well as Mogavero & Beaulieu, we review the possibility of measuring systematically the microlensing parallax using a telescope based on the Moon surface and other space-based observing platforms, including the upcoming WFIRST space-telescope. We first generalize the Fisher matrix formulation and present results demonstrating the advantage for each observing scenario. We conclude by outlining the limitation of the Fisher matrix analysis when submitted to a practical data modeling process. By considering a lunar-based parallax observation, we find that parameter correlations introduce a significant loss in detection efficiency of the probed lunar parallax effect.

  18. WSN-Based Space Charge Density Measurement System.

    Science.gov (United States)

    Deng, Dawei; Yuan, Haiwen; Lv, Jianxun; Ju, Yong

    2017-01-01

    It is generally acknowledged that high voltage direct current (HVDC) transmission line endures the drawback of large area, because of which the utilization of cable for space charge density monitoring system is of inconvenience. Compared with the traditional communication network, wireless sensor network (WSN) shows advantages in small volume, high flexibility and strong self-organization, thereby presenting great potential in solving the problem. Additionally, WSN is more suitable for the construction of distributed space charge density monitoring system as it has longer distance and higher mobility. A distributed wireless system is designed for collecting and monitoring the space charge density under HVDC transmission lines, which has been widely applied in both Chinese state grid HVDC test base and power transmission projects. Experimental results of the measuring system demonstrated its adaptability in the complex electromagnetic environment under the transmission lines and the ability in realizing accurate, flexible, and stable demands for the measurement of space charge density.

  19. Thermal Analysis of MIRIS Space Observation Camera for Verification of Passive Cooling

    Directory of Open Access Journals (Sweden)

    Duk-Hang Lee

    2012-09-01

    Full Text Available We conducted thermal analyses and cooling tests of the space observation camera (SOC of the multi-purpose infrared imaging system (MIRIS to verify passive cooling. The thermal analyses were conducted with NX 7.0 TMG for two cases of attitude of the MIRIS: for the worst hot case and normal case. Through the thermal analyses of the flight model, it was found that even in the worst case the telescope could be cooled to less than 206°K. This is similar to the results of the passive cooling test (~200.2°K. For the normal attitude case of the analysis, on the other hand, the SOC telescope was cooled to about 160°K in 10 days. Based on the results of these analyses and the test, it was determined that the telescope of the MIRIS SOC could be successfully cooled to below 200°K with passive cooling. The SOC is, therefore, expected to have optimal performance under cooled conditions in orbit.

  20. Theory and experiments in model-based space system anomaly management

    Science.gov (United States)

    Kitts, Christopher Adam

    This research program consists of an experimental study of model-based reasoning methods for detecting, diagnosing and resolving anomalies that occur when operating a comprehensive space system. Using a first principles approach, several extensions were made to the existing field of model-based fault detection and diagnosis in order to develop a general theory of model-based anomaly management. Based on this theory, a suite of algorithms were developed and computationally implemented in order to detect, diagnose and identify resolutions for anomalous conditions occurring within an engineering system. The theory and software suite were experimentally verified and validated in the context of a simple but comprehensive, student-developed, end-to-end space system, which was developed specifically to support such demonstrations. This space system consisted of the Sapphire microsatellite which was launched in 2001, several geographically distributed and Internet-enabled communication ground stations, and a centralized mission control complex located in the Space Technology Center in the NASA Ames Research Park. Results of both ground-based and on-board experiments demonstrate the speed, accuracy, and value of the algorithms compared to human operators, and they highlight future improvements required to mature this technology.

  1. Improved Space Object Orbit Determination Using CMOS Detectors

    Science.gov (United States)

    Schildknecht, T.; Peltonen, J.; Sännti, T.; Silha, J.; Flohrer, T.

    2014-09-01

    CMOS-sensors, or in general Active Pixel Sensors (APS), are rapidly replacing CCDs in the consumer camera market. Due to significant technological advances during the past years these devices start to compete with CCDs also for demanding scientific imaging applications, in particular in the astronomy community. CMOS detectors offer a series of inherent advantages compared to CCDs, due to the structure of their basic pixel cells, which each contains their own amplifier and readout electronics. The most prominent advantages for space object observations are the extremely fast and flexible readout capabilities, feasibility for electronic shuttering and precise epoch registration, and the potential to perform image processing operations on-chip and in real-time. The major challenges and design drivers for ground-based and space-based optical observation strategies have been analyzed. CMOS detector characteristics were critically evaluated and compared with the established CCD technology, especially with respect to the above mentioned observations. Similarly, the desirable on-chip processing functionalities which would further enhance the object detection and image segmentation were identified. Finally, we simulated several observation scenarios for ground- and space-based sensor by assuming different observation and sensor properties. We will introduce the analyzed end-to-end simulations of the ground- and space-based strategies in order to investigate the orbit determination accuracy and its sensitivity which may result from different values for the frame-rate, pixel scale, astrometric and epoch registration accuracies. Two cases were simulated, a survey using a ground-based sensor to observe objects in LEO for surveillance applications, and a statistical survey with a space-based sensor orbiting in LEO observing small-size debris in LEO. The ground-based LEO survey uses a dynamical fence close to the Earth shadow a few hours after sunset. For the space-based scenario

  2. Alamos: An International Collaboration to Provide a Space Based Environmental Monitoring Solution for the Deep Space Network

    Science.gov (United States)

    Kennedy, S. O.; Dunn, A.; Lecomte, J.; Buchheim, K.; Johansson, E.; Berger, T.

    2018-02-01

    This abstract proposes the advantages of an externally mounted instrument in support of the human physiology, space biology, and human health and performance key science area. Alamos provides Space-Based Environmental Monitoring capabilities.

  3. Sentinel-2: next generation satellites for optical land observation from space

    Science.gov (United States)

    Lautenschläger, G.; Gessner, R.; Gockel, W.; Haas, C.; Schweickert, G.; Bursch, S.; Welsch, M.; Sontag, H.

    2013-10-01

    The first Sentinel-2 satellites, which constitute the next generation of operational Earth observation satellites for optical land monitoring from space, are undergoing completion in the facilities at Astrium ready for launch end 2014. Sentinel-2 will feature a major breakthrough in the area of optical land observation since it will for the first time enable continuous and systematic acquisition of all land surfaces world-wide with the Multi-Spectral Instrument (MSI), thus providing the basis for a truly operational service. Flying in the same orbital plane and spaced at 180°, the constellation of two satellites, designed for an in-orbit nominal operational lifetime of 7 years each, will acquire all land surfaces in only 5 days at the equator. In order to support emergency operations, the satellites can further be operated in an extended observation mode allowing to image any point on Earth even on a daily basis. MSI acquires images in 13 spectral channels from Visible-to-Near Infrared (VNIR) to Short Wave Infrared (SWIR) with a swath of almost 300 km on ground and a spatial resolution up to 10 m. The data ensure continuity to the existing data sets produced by the series of Landsat and SPOT satellites, and will further provide detailed spectral information to enable derivation of biophysical or geophysical products. Excellent geometric image quality performances are achieved with geolocation better than 16 m, thanks to an innovative instrument design in conjunction with a high-performance satellite AOCS subsystem centered around a 2-band GPS receiver, high-performance star trackers and a fiberoptic gyro. To cope with the high data volume on-board, data are compressed using a state-of-the-art wavelet compression scheme. Thanks to a powerful mission data handling system built around a newly developed very large solid-state mass memory based on flash technology, on-board compression losses will be kept to a minimum. The Sentinel-2 satellite design features a highly

  4. Development of cultural tourism area based on the spiritual space of Cirebon Keraton

    Science.gov (United States)

    Rosmalia, D.; Prasetya, L. E.

    2018-03-01

    Cirebon is a city laden with spiritual activities. These are held almost every month in a year, by palace (keraton) disciples from surrounding Cirebon region and Indonesia. The spiritual events are located in almost of sacred places of keratons around Cirebon, and make an imaginary sacred space from the south to the north of Cirebon city. Sacred spiritual space is potential to be developed into tourism area destination, especially for religious tourist. Therefore, this study aims to explore an attractiveness of tourism, based on the spiritual area of keraton disciples, as a part of the cultural tourism space of Cirebon. To explore tourism potential, this research used survey and observation method in the palace, and in-depth interview with seven key persons, i.e., palace informants. After that, this potential was developed for the planning of tourist areas based on spiritual tourism destinations, divided by the core and the supporting areas, formed by sacred places and major tourist attractions. The core area is located in two locations, i.e., (1) the area of Cirebon keratons, and (2) complexes of graves on Gunung Jati. Meanwhile, the supporting area is formed by other supporting tourist objects and the ritual route of tourism.

  5. High Temporal Resolution Tropospheric Wind Profile Observations at NASA Kennedy Space Center During Hurricane Irma

    Science.gov (United States)

    Decker, Ryan K.; Barbre, Robert E., Jr.; Huddleston, Lisa; Brauer, Thomas; Wilfong, Timothy

    2018-01-01

    The NASA Kennedy Space Center (KSC) operates a 48-MHz Tropospheric/Stratospheric Doppler Radar Wind Profiler (TDRWP) on a continual basis generating wind profiles between 2-19 km in the support of space launch vehicle operations. A benefit of the continual operability of the system is the ability to provide unique observations of severe weather events such as hurricanes. Over the past two Atlantic Hurricane seasons the TDRWP has made high temporal resolution wind profile observations of Hurricane Irma in 2017 and Hurricane Matthew in 2016. Hurricane Irma was responsible for power outages to approximately 2/3 of Florida's population during its movement over the state(Stein,2017). An overview of the TDRWP system configuration, brief summary of Hurricanes Irma and Matthew storm track in proximity to KSC, characteristics of the tropospheric wind observations from the TDRWP during both events, and discussion of the dissemination of TDRWP data during the event will be presented.

  6. Earth rotation excitation mechanisms derived from geodetic space observations

    Science.gov (United States)

    Göttl, F.; Schmidt, M.

    2009-04-01

    Earth rotation variations are caused by mass displacements and motions in the subsystems of the Earth. Via the satellite Gravity and Climate Experiment (GRACE) gravity field variations can be identified which are caused by mass redistribution in the Earth system. Therefore time variable gravity field models (GFZ RL04, CSR RL04, JPL RL04, ITG-Grace03, GRGS, ...) can be used to derive different impacts on Earth rotation. Furthermore satellite altimetry provides accurate information on sea level anomalies (AVISO, DGFI) which are caused by mass and volume changes of seawater. Since Earth rotation is solely affected by mass variations and motions the volume (steric) effect has to be reduced from the altimetric observations in order to infer oceanic contributions to Earth rotation variations. Therefore the steric effect is estimated from physical ocean parameters such as temperature and salinity changes in the oceans (WOA05, Ishii). In this study specific individual geophysical contributions to Earth rotation variations are identified by means of a multitude of accurate geodetic space observations in combination with a realistic error propagation. It will be shown that due to adjustment of altimetric and/or gravimetric solutions the results for polar motion excitations can be improved.

  7. Observations of Heliospheric Faraday Rotation (FR) and Interplanetary Scintillation (IPS) with the LOw Frequency ARray (LOFAR): Steps Towards Improving Space-Weather Forecasting Capabilities

    Science.gov (United States)

    Bisi, M. M.; Fallows, R. A.; Sobey, C.; Eftekhari, T.; Jensen, E. A.; Jackson, B. V.; Yu, H. S.; Hick, P. P.; Odstrcil, D.; Tokumaru, M.

    2015-12-01

    The phenomenon of space weather - analogous to terrestrial weather which describes the changing pressure, temperature, wind, and humidity conditions on Earth - is essentially a description of the changes in velocity, density, magnetic field, high-energy particles, and radiation in the near-Earth space environment including the effects of such changes on the Earth's magnetosphere, radiation belts, ionosphere, and thermosphere. Space weather can be considered to have two main strands: (i) scientific research, and (ii) applications. The former is self-explanatory, but the latter covers operational aspects which includes its forecasting. Understanding and forecasting space weather in the near-Earth environment is vitally important to protecting our modern-day reliance (militarily and commercially) on satellites, global-communication and navigation networks, high-altitude air travel (radiation concerns particularly on polar routes), long-distance power/oil/gas lines and piping, and for any future human exploration of space to list but a few. Two ground-based radio-observing remote-sensing techniques that can aid our understanding and forecasting of heliospheric space weather are those of interplanetary scintillation (IPS) and heliospheric Faraday rotation (FR). The LOw Frequency ARray (LOFAR) is a next-generation 'software' radio telescope centered in The Netherlands with international stations spread across central and northwest Europe. For several years, scientific observations of IPS on LOFAR have been undertaken on a campaign basis and the experiment is now well developed. More recently, LOFAR has been used to attempt scientific heliospheric FR observations aimed at remotely sensing the magnetic field of the plasma traversing the inner heliosphere. We present our latest progress using these two radio heliospheric-imaging remote-sensing techniques including the use of three-dimensional (3-D) modeling and reconstruction techniques using other, additional data as input

  8. Complexity in Simplicity: Flexible Agent-based State Space Exploration

    DEFF Research Database (Denmark)

    Rasmussen, Jacob Illum; Larsen, Kim Guldstrand

    2007-01-01

    In this paper, we describe a new flexible framework for state space exploration based on cooperating agents. The idea is to let various agents with different search patterns explore the state space individually and communicate information about fruitful subpaths of the search tree to each other...

  9. Cauchy problem for Laplace equation: An observer based approach

    KAUST Repository

    Majeed, Muhammad Usman

    2013-10-01

    A method to solve Cauchy Problem for Laplace equation using state observers is proposed. It is known that this problem is ill-posed. The domain under consideration is simple lipschitz in 2 with a hole. The idea is to recover the solution over whole domain from the observations on outer boundary. Proposed approach adapts one of the space variables as a time variable. The observer developed to solve Cauchy problem for the Laplace\\'s equation is compuationally robust and accurate. © 2013 IEEE.

  10. Engineering graphics data entry for space station data base

    Science.gov (United States)

    Lacovara, R. C.

    1986-01-01

    The entry of graphical engineering data into the Space Station Data Base was examined. Discussed were: representation of graphics objects; representation of connectivity data; graphics capture hardware; graphics display hardware; site-wide distribution of graphics, and consolidation of tools and hardware. A fundamental assumption was that existing equipment such as IBM based graphics capture software and VAX networked facilities would be exploited. Defensible conclusions reached after study and simulations of use of these systems at the engineering level are: (1) existing IBM based graphics capture software is an adequate and economical means of entry of schematic and block diagram data for present and anticipated electronic systems for Space Station; (2) connectivity data from the aforementioned system may be incorporated into the envisioned Space Station Data Base with modest effort; (3) graphics and connectivity data captured on the IBM based system may be exported to the VAX network in a simple and direct fashion; (4) graphics data may be displayed site-wide on VT-125 terminals and lookalikes; (5) graphics hard-copy may be produced site-wide on various dot-matrix printers; and (6) the system may provide integrated engineering services at both the engineering and engineering management level.

  11. Ground Based Support for Exoplanet Space Missions

    Science.gov (United States)

    Haukka, H.; Hentunen, V.-P.; Salmi, T.; Aartolahti, H.; Juutilainen, J.; Vilokki, H.; Nissinen, M.

    2011-10-01

    Taurus Hill Observatory (THO), observatory code A95, is an amateur observatory located in Varkaus, Finland. The observatory is maintained by the local astronomical association Warkauden Kassiopeia. THO research team has observed and measured various stellar objects and phenomena. Observatory has mainly focused to asteroid [1] and exoplanet light curve measurements, observing the gamma rays burst, supernova discoveries and monitoring [2] and long term monitoring projects [3]. In the early 2011 Europlanet NA1 and NA2 organized "Coordinated Observations of Exoplanets from Ground and Space"-workshop in Graz, Austria. The workshop gathered together proam astronomers who have the equipment to measure the light curves of the exoplanets. Also there were professional scientists working in the exoplanet field who attended to the workshop. The result of the workshop was to organize coordinated observation campaign for follow-up observations of exoplanets (e.g. CoRoT planets). Also coordinated observation campaign to observe stellar CME outbreaks was planned. THO has a lot of experience in field of exoplanet light curve measurements and therefore this campaign is very supported by the research team of the observatory. In next coming observing seasons THO will concentrate its efforts for this kind of campaigns.

  12. NASA space station automation: AI-based technology review. Executive summary

    Science.gov (United States)

    Firschein, O.; Georgeff, M. P.; Park, W.; Cheeseman, P. C.; Goldberg, J.; Neumann, P.; Kautz, W. H.; Levitt, K. N.; Rom, R. J.; Poggio, A. A.

    1985-01-01

    Research and Development projects in automation technology for the Space Station are described. Artificial Intelligence (AI) based technologies are planned to enhance crew safety through reduced need for EVA, increase crew productivity through the reduction of routine operations, increase space station autonomy, and augment space station capability through the use of teleoperation and robotics.

  13. Efficient Divide-And-Conquer Classification Based on Feature-Space Decomposition

    OpenAIRE

    Guo, Qi; Chen, Bo-Wei; Jiang, Feng; Ji, Xiangyang; Kung, Sun-Yuan

    2015-01-01

    This study presents a divide-and-conquer (DC) approach based on feature space decomposition for classification. When large-scale datasets are present, typical approaches usually employed truncated kernel methods on the feature space or DC approaches on the sample space. However, this did not guarantee separability between classes, owing to overfitting. To overcome such problems, this work proposes a novel DC approach on feature spaces consisting of three steps. Firstly, we divide the feature ...

  14. Dynamic auroral storms on Saturn as observed by the Hubble Space Telescope.

    Science.gov (United States)

    Nichols, J D; Badman, S V; Baines, K H; Brown, R H; Bunce, E J; Clarke, J T; Cowley, S W H; Crary, F J; Dougherty, M K; Gérard, J-C; Grocott, A; Grodent, D; Kurth, W S; Melin, H; Mitchell, D G; Pryor, W R; Stallard, T S

    2014-05-28

    We present observations of significant dynamics within two UV auroral storms observed on Saturn using the Hubble Space Telescope in April/May 2013. Specifically, we discuss bursts of auroral emission observed at the poleward boundary of a solar wind-induced auroral storm, propagating at ∼330% rigid corotation from near ∼01 h LT toward ∼08 h LT. We suggest that these are indicative of ongoing, bursty reconnection of lobe flux in the magnetotail, providing strong evidence that Saturn's auroral storms are caused by large-scale flux closure. We also discuss the later evolution of a similar storm and show that the emission maps to the trailing region of an energetic neutral atom enhancement. We thus identify the auroral form with the upward field-aligned continuity currents flowing into the associated partial ring current.

  15. US Air Force Base Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hourly observations taken by U.S. Air Force personnel at bases in the United States and around the world. Foreign observations concentrated in the Middle East and...

  16. Industrialization of Space: Microgravity Based Opportunities for Material and Life Science

    Science.gov (United States)

    Cozmuta, Ioana; Harper, Lynn D.; Rasky, Daniel J.; MacDonald, Alexander; Pittman, Robert

    2015-01-01

    Microgravity based commercial opportunities are broad, with applications ranging from fiber optics, device-grade semiconductor crystals, space beads, new materials, cell micro encapsulation, 3D tissues and cell cultures, genetic and molecular changes of immune suppression, protein and virus crystal growth, perfume and hair care. To date, primarily the knowledge gained from observing and understanding new end states of systems unraveled in microgravity has been translated into unique technologies and business opportunities on Earth. In some instances existing light qualified hardware is immediately available for commercial RD for small scale in-space manufacturing. Overall products manufactured in microgravity have key properties usually surpassing the best terrestrial counterparts. The talk will address the potential benefits of microgravity research for a variety of terrestrial markets. Our findings originate from discussions with 100+ non-aerospace private companies among the high-tech Silicon Valley ecosystem, show that the opportunities and benefits of using the ISS are largely not considered by experts, primarily due to a lack of awareness of the breadth of terrestrial applications that have been enabled or enhanced by microgravity RD. Based on this dialogue, the concept of microgravity verticals is developed to translate the benefits of the microgravity environment into blue ocean business opportunities for various key US commercial sectors.

  17. ON THE DETECTION AND TRACKING OF SPACE DEBRIS USING THE MURCHISON WIDEFIELD ARRAY. I. SIMULATIONS AND TEST OBSERVATIONS DEMONSTRATE FEASIBILITY

    Energy Technology Data Exchange (ETDEWEB)

    Tingay, S. J.; Wayth, R. B.; Hurley-Walker, N.; Kennewell, J.; Arcus, W.; Bhat, N. D. R.; Emrich, D.; Herne, D.; Kudryavtseva, N.; Lynch, M.; Ord, S. M.; Waterson, M. [International Centre for Radio Astronomy Research, Curtin University, Perth (Australia); Kaplan, D. L. [University of Wisconsin-Milwaukee, Milwaukee (United States); McKinley, B.; Briggs, F.; Bell, M.; Gaensler, B. M. [ARC Centre of Excellence for All-sky Astrophysics (CAASTRO), Sydney (Australia); Smith, C. [Electro Optic Systems Pty Ltd, Canberra (Australia); Zhang, K. [RMIT University, Melbourne (Australia); Barnes, D. G., E-mail: s.tingay@curtin.edu.au [Monash e-Research Centre, Monash University, Clayton (Australia); and others

    2013-10-01

    The Murchison Widefield Array (MWA) is a new low-frequency interferometric radio telescope, operating in the benign radio frequency environment of remote Western Australia. The MWA is the low-frequency precursor to the Square Kilometre Array (SKA) and is the first of three SKA precursors to be operational, supporting a varied science mission ranging from the attempted detection of the Epoch of Reionization to the monitoring of solar flares and space weather. In this paper we explore the possibility that the MWA can be used for the purposes of Space Situational Awareness (SSA). In particular we propose that the MWA can be used as an element of a passive radar facility operating in the frequency range 87.5-108 MHz (the commercial FM broadcast band). In this scenario the MWA can be considered the receiving element in a bi-static radar configuration, with FM broadcast stations serving as non-cooperative transmitters. The FM broadcasts propagate into space, are reflected off debris in Earth orbit, and are received at the MWA. The imaging capabilities of the MWA can be used to simultaneously detect multiple pieces of space debris, image their positions on the sky as a function of time, and provide tracking data that can be used to determine orbital parameters. Such a capability would be a valuable addition to Australian and global SSA assets, in terms of southern and eastern hemispheric coverage. We provide a feasibility assessment of this proposal, based on simple calculations and electromagnetic simulations, that shows that the detection of sub-meter size debris should be possible (debris radius of >0.5 m to ∼1000 km altitude). We also present a proof-of-concept set of observations that demonstrate the feasibility of the proposal, based on the detection and tracking of the International Space Station via reflected FM broadcast signals originating in southwest Western Australia. These observations broadly validate our calculations and simulations. We discuss some

  18. On the Detection and Tracking of Space Debris Using the Murchison Widefield Array. I. Simulations and Test Observations Demonstrate Feasibility

    Science.gov (United States)

    Tingay, S. J.; Kaplan, D. L.; McKinley, B.; Briggs, F.; Wayth, R. B.; Hurley-Walker, N.; Kennewell, J.; Smith, C.; Zhang, K.; Arcus, W.; Bhat, N. D. R.; Emrich, D.; Herne, D.; Kudryavtseva, N.; Lynch, M.; Ord, S. M.; Waterson, M.; Barnes, D. G.; Bell, M.; Gaensler, B. M.; Lenc, E.; Bernardi, G.; Greenhill, L. J.; Kasper, J. C.; Bowman, J. D.; Jacobs, D.; Bunton, J. D.; deSouza, L.; Koenig, R.; Pathikulangara, J.; Stevens, J.; Cappallo, R. J.; Corey, B. E.; Kincaid, B. B.; Kratzenberg, E.; Lonsdale, C. J.; McWhirter, S. R.; Rogers, A. E. E.; Salah, J. E.; Whitney, A. R.; Deshpande, A.; Prabu, T.; Udaya Shankar, N.; Srivani, K. S.; Subrahmanyan, R.; Ewall-Wice, A.; Feng, L.; Goeke, R.; Morgan, E.; Remillard, R. A.; Williams, C. L.; Hazelton, B. J.; Morales, M. F.; Johnston-Hollitt, M.; Mitchell, D. A.; Procopio, P.; Riding, J.; Webster, R. L.; Wyithe, J. S. B.; Oberoi, D.; Roshi, A.; Sault, R. J.; Williams, A.

    2013-10-01

    The Murchison Widefield Array (MWA) is a new low-frequency interferometric radio telescope, operating in the benign radio frequency environment of remote Western Australia. The MWA is the low-frequency precursor to the Square Kilometre Array (SKA) and is the first of three SKA precursors to be operational, supporting a varied science mission ranging from the attempted detection of the Epoch of Reionization to the monitoring of solar flares and space weather. In this paper we explore the possibility that the MWA can be used for the purposes of Space Situational Awareness (SSA). In particular we propose that the MWA can be used as an element of a passive radar facility operating in the frequency range 87.5-108 MHz (the commercial FM broadcast band). In this scenario the MWA can be considered the receiving element in a bi-static radar configuration, with FM broadcast stations serving as non-cooperative transmitters. The FM broadcasts propagate into space, are reflected off debris in Earth orbit, and are received at the MWA. The imaging capabilities of the MWA can be used to simultaneously detect multiple pieces of space debris, image their positions on the sky as a function of time, and provide tracking data that can be used to determine orbital parameters. Such a capability would be a valuable addition to Australian and global SSA assets, in terms of southern and eastern hemispheric coverage. We provide a feasibility assessment of this proposal, based on simple calculations and electromagnetic simulations, that shows that the detection of sub-meter size debris should be possible (debris radius of >0.5 m to ~1000 km altitude). We also present a proof-of-concept set of observations that demonstrate the feasibility of the proposal, based on the detection and tracking of the International Space Station via reflected FM broadcast signals originating in southwest Western Australia. These observations broadly validate our calculations and simulations. We discuss some

  19. ON THE DETECTION AND TRACKING OF SPACE DEBRIS USING THE MURCHISON WIDEFIELD ARRAY. I. SIMULATIONS AND TEST OBSERVATIONS DEMONSTRATE FEASIBILITY

    International Nuclear Information System (INIS)

    Tingay, S. J.; Wayth, R. B.; Hurley-Walker, N.; Kennewell, J.; Arcus, W.; Bhat, N. D. R.; Emrich, D.; Herne, D.; Kudryavtseva, N.; Lynch, M.; Ord, S. M.; Waterson, M.; Kaplan, D. L.; McKinley, B.; Briggs, F.; Bell, M.; Gaensler, B. M.; Smith, C.; Zhang, K.; Barnes, D. G.

    2013-01-01

    The Murchison Widefield Array (MWA) is a new low-frequency interferometric radio telescope, operating in the benign radio frequency environment of remote Western Australia. The MWA is the low-frequency precursor to the Square Kilometre Array (SKA) and is the first of three SKA precursors to be operational, supporting a varied science mission ranging from the attempted detection of the Epoch of Reionization to the monitoring of solar flares and space weather. In this paper we explore the possibility that the MWA can be used for the purposes of Space Situational Awareness (SSA). In particular we propose that the MWA can be used as an element of a passive radar facility operating in the frequency range 87.5-108 MHz (the commercial FM broadcast band). In this scenario the MWA can be considered the receiving element in a bi-static radar configuration, with FM broadcast stations serving as non-cooperative transmitters. The FM broadcasts propagate into space, are reflected off debris in Earth orbit, and are received at the MWA. The imaging capabilities of the MWA can be used to simultaneously detect multiple pieces of space debris, image their positions on the sky as a function of time, and provide tracking data that can be used to determine orbital parameters. Such a capability would be a valuable addition to Australian and global SSA assets, in terms of southern and eastern hemispheric coverage. We provide a feasibility assessment of this proposal, based on simple calculations and electromagnetic simulations, that shows that the detection of sub-meter size debris should be possible (debris radius of >0.5 m to ∼1000 km altitude). We also present a proof-of-concept set of observations that demonstrate the feasibility of the proposal, based on the detection and tracking of the International Space Station via reflected FM broadcast signals originating in southwest Western Australia. These observations broadly validate our calculations and simulations. We discuss some

  20. A Ground-based validation of GOSAT-observed atmospheric CO2 in Inner-Mongolian grasslands

    International Nuclear Information System (INIS)

    Qin, X; Lei, L; Zeng, Z; Kawasaki, M; Oohasi, M

    2014-01-01

    Atmospheric carbon dioxide (CO 2 ) is a long-lived greenhouse gas that significantly contributes to global warming. Long-term and continuous measurements of atmospheric CO 2 to investigate its global distribution and concentration variations are important for accurately understanding its potential climatic effects. Satellite measurements from space can offer atmospheric CO 2 data for climate change research. For that, ground-based measurements are required for validation and improving the precision of satellite-measured CO 2 . We implemented observation experiment of CO 2 column densities in the Xilinguole grasslands in Inner Mongolia, China, using a ground-based measurement system, which mainly consists of an optical spectrum analyzer (OSA), a sun tracker and a notebook controller. Measurements from our ground-based system were analyzed and compared with those from the Greenhouse gas Observation SATellite (GOSAT). The ground-based measurements had an average value of 389.46 ppm, which was 2.4 ppm larger than from GOSAT, with a standard deviation of 3.4 ppm. This result is slightly larger than the difference between GOSAT and the Total Carbon Column Observing Network (TCCON). This study highlights the usefulness of the ground-based OSA measurement system for analyzing atmospheric CO 2 column densities, which is expected to supplement the current TCCON network

  1. Estimation of time averages from irregularly spaced observations - With application to coastal zone color scanner estimates of chlorophyll concentration

    Science.gov (United States)

    Chelton, Dudley B.; Schlax, Michael G.

    1991-01-01

    The sampling error of an arbitrary linear estimate of a time-averaged quantity constructed from a time series of irregularly spaced observations at a fixed located is quantified through a formalism. The method is applied to satellite observations of chlorophyll from the coastal zone color scanner. The two specific linear estimates under consideration are the composite average formed from the simple average of all observations within the averaging period and the optimal estimate formed by minimizing the mean squared error of the temporal average based on all the observations in the time series. The resulting suboptimal estimates are shown to be more accurate than composite averages. Suboptimal estimates are also found to be nearly as accurate as optimal estimates using the correct signal and measurement error variances and correlation functions for realistic ranges of these parameters, which makes it a viable practical alternative to the composite average method generally employed at present.

  2. Observing Tsunamis in the Ionosphere Using Ground Based GPS Measurements

    Science.gov (United States)

    Galvan, D. A.; Komjathy, A.; Song, Y. Tony; Stephens, P.; Hickey, M. P.; Foster, J.

    2011-01-01

    Ground-based Global Positioning System (GPS) measurements of ionospheric Total Electron Content (TEC) show variations consistent with atmospheric internal gravity waves caused by ocean tsunamis following recent seismic events, including the Tohoku tsunami of March 11, 2011. We observe fluctuations correlated in time, space, and wave properties with this tsunami in TEC estimates processed using JPL's Global Ionospheric Mapping Software. These TEC estimates were band-pass filtered to remove ionospheric TEC variations with periods outside the typical range of internal gravity waves caused by tsunamis. Observable variations in TEC appear correlated with the Tohoku tsunami near the epicenter, at Hawaii, and near the west coast of North America. Disturbance magnitudes are 1-10% of the background TEC value. Observations near the epicenter are compared to estimates of expected tsunami-driven TEC variations produced by Embry Riddle Aeronautical University's Spectral Full Wave Model, an atmosphere-ionosphere coupling model, and found to be in good agreement. The potential exists to apply these detection techniques to real-time GPS TEC data, providing estimates of tsunami speed and amplitude that may be useful for future early warning systems.

  3. Fragmented perception: slower space-based but faster object-based attention in recent-onset psychosis with and without Schizophrenia.

    Directory of Open Access Journals (Sweden)

    Henderikus G O M Smid

    Full Text Available BACKGROUND: Schizophrenia is associated with impairments of the perception of objects, but how this affects higher cognitive functions, whether this impairment is already present after recent onset of psychosis, and whether it is specific for schizophrenia related psychosis, is not clear. We therefore tested the hypothesis that because schizophrenia is associated with impaired object perception, schizophrenia patients should differ in shifting attention between objects compared to healthy controls. To test this hypothesis, a task was used that allowed us to separately observe space-based and object-based covert orienting of attention. To examine whether impairment of object-based visual attention is related to higher order cognitive functions, standard neuropsychological tests were also administered. METHOD: Patients with recent onset psychosis and normal controls performed the attention task, in which space- and object-based attention shifts were induced by cue-target sequences that required reorienting of attention within an object, or reorienting attention between objects. RESULTS: Patients with and without schizophrenia showed slower than normal spatial attention shifts, but the object-based component of attention shifts in patients was smaller than normal. Schizophrenia was specifically associated with slowed right-to-left attention shifts. Reorienting speed was significantly correlated with verbal memory scores in controls, and with visual attention scores in patients, but not with speed-of-processing scores in either group. CONCLUSIONS: deficits of object-perception and spatial attention shifting are not only associated with schizophrenia, but are common to all psychosis patients. Schizophrenia patients only differed by having abnormally slow right-to-left visual field reorienting. Deficits of object-perception and spatial attention shifting are already present after recent onset of psychosis. Studies investigating visual spatial

  4. Sensitivity studies for a space-based methane lidar mission

    Directory of Open Access Journals (Sweden)

    C. Kiemle

    2011-10-01

    Full Text Available Methane is the third most important greenhouse gas in the atmosphere after water vapour and carbon dioxide. A major handicap to quantify the emissions at the Earth's surface in order to better understand biosphere-atmosphere exchange processes and potential climate feedbacks is the lack of accurate and global observations of methane. Space-based integrated path differential absorption (IPDA lidar has potential to fill this gap, and a Methane Remote Lidar Mission (MERLIN on a small satellite in polar orbit was proposed by DLR and CNES in the frame of a German-French climate monitoring initiative. System simulations are used to identify key performance parameters and to find an advantageous instrument configuration, given the environmental, technological, and budget constraints. The sensitivity studies use representative averages of the atmospheric and surface state to estimate the measurement precision, i.e. the random uncertainty due to instrument noise. Key performance parameters for MERLIN are average laser power, telescope size, orbit height, surface reflectance, and detector noise. A modest-size lidar instrument with 0.45 W average laser power and 0.55 m telescope diameter on a 506 km orbit could provide 50-km averaged methane column measurement along the sub-satellite track with a precision of about 1% over vegetation. The use of a methane absorption trough at 1.65 μm improves the near-surface measurement sensitivity and vastly relaxes the wavelength stability requirement that was identified as one of the major technological risks in the pre-phase A studies for A-SCOPE, a space-based IPDA lidar for carbon dioxide at the European Space Agency. Minimal humidity and temperature sensitivity at this wavelength position will enable accurate measurements in tropical wetlands, key regions with largely uncertain methane emissions. In contrast to actual passive remote sensors, measurements in Polar Regions will be possible and biases due to aerosol

  5. Generalized probabilistic scale space for image restoration.

    Science.gov (United States)

    Wong, Alexander; Mishra, Akshaya K

    2010-10-01

    A novel generalized sampling-based probabilistic scale space theory is proposed for image restoration. We explore extending the definition of scale space to better account for both noise and observation models, which is important for producing accurately restored images. A new class of scale-space realizations based on sampling and probability theory is introduced to realize this extended definition in the context of image restoration. Experimental results using 2-D images show that generalized sampling-based probabilistic scale-space theory can be used to produce more accurate restored images when compared with state-of-the-art scale-space formulations, particularly under situations characterized by low signal-to-noise ratios and image degradation.

  6. Representations of space based on haptic input

    NARCIS (Netherlands)

    Zuidhoek, S.

    2005-01-01

    The present thesis focused on the representations of grasping space based on haptic input. We aimed at identifying their characteristics, and the underlying neurocognitive processes and mechanisms. To this end, we studied the systematic distortions in performance on several orientation perception

  7. The Latest Space-Borne Observations of TGFs from Fermi-GBM

    Science.gov (United States)

    Fishman, Gerald J.

    2010-01-01

    The Gamma-ray Burst Monitor (GBM) on the Fermi Gamma-ray Space Telescope Observatory (Fermi) is detecting about two TGFs per week. This rate has increased by a factor of approx.eight since launch when flight software was uploaded to the spacecraft in November 2009 in order to increase the sensitivity of GBM to TGFs. Weaker, un-triggered TGFs are now also being observed about once per day over selected low-latitude regions Americas. The high efficiency and time resolution (2 s) of GBM allows temporal features to be resolved so that some insight may be gained on the origin and transport of the gamma-ray photons through the atmosphere. TGFs are observed to be shorter than previously thought, with an average duration of approx.100 micro-s. The absolute times of TGFs are known to approx.10 micro-s, allowing accurate correlations of TGFs with lightning networks and other lightning-related phenomena. The events are observed in the thick bismuth germanate (BGO) scintillation detectors of GBM with photon energies above 40 MeV. Other new results on the temporal and spectral characteristics of TGFs will be presented, along with properties of several electron-positron TGF events that have been identified.

  8. HUBBLE SPACE TELESCOPE OBSERVATIONS OF MAIN-BELT COMET (596) SCHEILA

    International Nuclear Information System (INIS)

    Jewitt, David; Weaver, Harold; Mutchler, Max; Larson, Stephen; Agarwal, Jessica

    2011-01-01

    We present Hubble Space Telescope Observations of (596) Scheila during its recent dust outburst. The nucleus remained point-like with absolute magnitude H V = 8.85 ± 0.02 in our data, equal to the pre-outburst value, with no secondary fragments of diameter ≥100 m (for assumed albedos 0.04). We find a coma having a peak scattering cross section ∼2.2x10 4 km 2 , corresponding to a mass in micron-sized particles of ∼4x10 7 kg. The particles are deflected by solar radiation pressure on projected spatial scales ∼2x10 4 km, in the sunward direction, and swept from the vicinity of the nucleus on timescales of weeks. The coma fades by ∼30% between observations on UT 2010 December 27 and 2011 January 4. The observed mass loss is inconsistent with an origin either by rotational instability of the nucleus or by electrostatic ejection of regolith charged by sunlight. Dust ejection could be caused by the sudden but unexplained exposure of buried ice. However, the data are most simply explained by the impact, at ∼5 km s -1 , of a previously unknown asteroid ∼35 m in diameter.

  9. Driver ASIC Environmental Testing and Performance Optimization for SpaceBased Active Mirrors

    Science.gov (United States)

    Mejia Prada, Camilo

    Direct imaging of Earth-like planets requires techniques for light suppression, such as coronagraphs or nulling interferometers, in which deformable mirrors (DM) are a principal component. On ground-based systems, DMs are used to correct for turbulence in the Earth’s atmosphere in addition to static aberrations in the optics. For space-based observations, DMs are used to correct for static and quasi- static aberrations in the optical train. State-of-the-art, high-actuator count deformable mirrors suffer from external heavy and bulky electronics in which electrical connections are made through thousands of wires. We are instead developing Application Specific Integrated Circuits (ASICs) capable of direct integration with the DM in a single small package. This integrated ASIC-DM is ideal for space missions, where it offers significant reduction in mass, power and complexity, and performance compatible with high-contrast observations of exoplanets. We have successfully prototyped and tested a 32x32 format Switch-Mode (SM) ASIC which consumes only 2mW static power (total, not per-actuator). A number of constraints were imposed on key parameters of this ASIC design, including sub-picoamp levels of leakage across turned-off switches and from switch-to-substrate, control resolution of 0.04 mV, satisfactory rise/fall times, and a near-zero on-chip crosstalk over a useful range of operating temperatures. This driver ASIC technology is currently at TRL 4. This Supporting Technology proposal will further develop the ASIC technology to TRL 5 by carrying on environmental tests and further optimizing performance, with the end goal of making ASICs suitable for space-based deployment. The effort will be led by JPL, which has considerable expertise with DMs used in highcontrast imaging systems for exoplanet missions and in adaptive optic systems, and in design of DM driver electronics. Microscale, which developed the prototype of the ASICDM, will continue its development. We

  10. Competitive market-based allocation of consumer attention space

    OpenAIRE

    Bohte, Sander; Gerding, Enrico; La Poutré, Han

    2001-01-01

    textabstractThe amount of attention space available for recommending suppliers to consumers on e-commerce sites is typically limited. We present a competitive distributed recommendation mechanism based on adaptive software agents for efficiently allocating the 'consumer attention space', or banners. In the example of an electronic shopping mall, the task is delegated to the individual shops, each of which evaluates the information that is available about the consumer and his or her interests ...

  11. Entanglement-based Free Space Quantum Cryptography in Daylight

    Science.gov (United States)

    Gerhardt, Ilja; Peloso, Matthew P.; Ho, Caleb; Lamas-Linares, Antia; Kurtsiefer, Christian

    2009-05-01

    In quantum key distribution (QKD) two families of protocols are established: One, based on preparing and sending approximations of single photons, the other based on measurements on entangled photon pairs, which allow to establish a secret key using less assumptions on the size of a Hilbert space. The larger optical bandwidth of photon pairs in comparison with light used for the first family makes establishing a free space link challenging. We present a complete entanglement based QKD system following the BBM92 protocol, which generates a secure key continuously 24 hours a day between distant parties. Spectral, spatial and temporal filtering schemes were introduced to a previous setup, suppressing more than 30,B of background. We are able to establish the link during daytime, and have developed an algorithm to start and maintain time synchronization with simple crystal oscillators.

  12. Accelerometer for Space Applications Based on Light-Pulse Atom Interferometry, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to build a compact, high-precision single-axis accelerometer based on atom interferometry that is applicable to operation in space environments. Based on...

  13. Special Relativity Corrections for Space-Based Lidars

    Science.gov (United States)

    RaoGudimetla, Venkata S.; Kavaya, Michael J.

    1999-01-01

    The theory of special relativity is used to analyze some of the physical phenomena associated with space-based coherent Doppler lidars aimed at Earth and the atmosphere. Two important cases of diffuse scattering and retroreflection by lidar targets are treated. For the case of diffuse scattering, we show that for a coaligned transmitter and receiver on the moving satellite, there is no angle between transmitted and returned radiation. However, the ray that enters the receiver does not correspond to a retroreflected ray by the target. For the retroreflection case there is misalignment between the transmitted ray and the received ray. In addition, the Doppler shift in the frequency and the amount of tip for the receiver aperture when needed are calculated, The error in estimating wind because of the Doppler shift in the frequency due to special relativity effects is examined. The results are then applied to a proposed space-based pulsed coherent Doppler lidar at NASA's Marshall Space Flight Center for wind and aerosol backscatter measurements. The lidar uses an orbiting spacecraft with a pulsed laser source and measures the Doppler shift between the transmitted and the received frequencies to determine the atmospheric wind velocities. We show that the special relativity effects are small for the proposed system.

  14. Space-based societal applications—Relevance in developing countries

    Science.gov (United States)

    Bhaskaranarayana, A.; Varadarajan, C.; Hegde, V. S.

    2009-11-01

    Space technology has the vast potential for addressing a variety of societal problems of the developing countries, particularly in the areas of communication, education and health sectors, land and water resources management, disaster management and weather forecasting. Both remote sensing and communication technologies can be used to achieve this goal. With its primary emphasis on application of space technology, on an end-to-end basis, towards national development, the Indian Space Programme has distinguished itself as one of the most cost-effective and development-oriented space programmes in the world. Developing nations are faced with the enormous task of carrying development-oriented education to the masses at the lower strata of their societies. One important feature of these populations is their large number and the spread over vast and remote areas of these nations, making the reaching out to them a difficult task. Satellite communication (Satcom) technology offers the unique capability of simultaneously reaching out to very large numbers, spread over vast areas, including the remote corners of the country. It is a strong tool to support development education. India has been amongst the first few nations to explore and put to use the Satcom technology for education and development-oriented services to the rural masses. Most of the developing countries have inadequate infrastructure to provide proper medical care to the rural population. Availability of specialist doctors in rural areas is a major bottleneck. Use of Satcom and information technology to connect rural clinics to urban hospitals through telemedicine systems is one of the solutions; and India has embarked upon an effective satellite-based telemedicine programme. Space technology is also useful in disaster warning and management related applications. Use of satellite systems and beacons for locating the distressed units on land, sea or air is well known to us. Indian Space Research Organisation

  15. All-sky-imaging capabilities for ionospheric space weather research using geomagnetic conjugate point observing sites

    Science.gov (United States)

    Martinis, C.; Baumgardner, J.; Wroten, J.; Mendillo, M.

    2018-04-01

    Optical signatures of ionospheric disturbances exist at all latitudes on Earth-the most well known case being visible aurora at high latitudes. Sub-visual emissions occur equatorward of the auroral zones that also indicate periods and locations of severe Space Weather effects. These fall into three magnetic latitude domains in each hemisphere: (1) sub-auroral latitudes ∼40-60°, (2) mid-latitudes (20-40°) and (3) equatorial-to-low latitudes (0-20°). Boston University has established a network of all-sky-imagers (ASIs) with sites at opposite ends of the same geomagnetic field lines in each hemisphere-called geomagnetic conjugate points. Our ASIs are autonomous instruments that operate in mini-observatories situated at four conjugate pairs in North and South America, plus one pair linking Europe and South Africa. In this paper, we describe instrument design, data-taking protocols, data transfer and archiving issues, image processing, science objectives and early results for each latitude domain. This unique capability addresses how a single source of disturbance is transformed into similar or different effects based on the unique "receptor" conditions (seasonal effects) found in each hemisphere. Applying optical conjugate point observations to Space Weather problems offers a new diagnostic approach for understanding the global system response functions operating in the Earth's upper atmosphere.

  16. Earth-Space Propagation Data Bases

    Science.gov (United States)

    Smith, Ernest K.

    1996-01-01

    This paper, designed for the newcomer rather than the expert, will take a rather broad view of what is meant by 'propagation data bases' in that it will take the term to mean both the actual measurements and models of Earth-space paths. The text will largely be drawn from International Radio Consultative Committee (CCIR) reports, now annexed to the Recommendations of the International Telecommunications Union-R Study Group 3, plus some experience with a course taught at the University of Colorado.

  17. On the progress of the nano-satellite SAR based mission TOPMEX-9 and specification of potential applications advancing the Earth Observation Programme of the Mexican Space Agency.

    Science.gov (United States)

    Ocampo-Torres, Francisco J.; Gutiérrez-Nava, Antonio; Ponce, Octavio; Vicente-Vivas, Esaú; Pacheco, Enrique

    2013-04-01

    TOPMEX-9 is put forward in this paper, advancing a mission for the Earth Observation Programme of the Mexican Space Agency, a distributed Micro-SAR concept within a Master and Slaves flight formation. International collaboration is essential and a start project is being developed between the Microwaves and Radar Institute of the German Aerospace Centre (DLR), the Mexican Space Agency (AEM). While the basic idea is making use of the transmitting component of a SAR on a microsatellite and the receiving component on a nano-satellites cluster, only a brief illustration is given here. The objective of this work is mainly to present some SAR characteristics and the most important potential applications. Special attention is given to the capabilities and limitations of SAR systems to properly detect ocean surface waves. We do take into account the nonlinear nature of the ocean surface imaging porcesses, mainly based upon the SAR and the waves characteristics, and certainly considering the K band SAR being proposed. Some other ocean applications are also overview, regarding coastal erosion-deposition estimation, as well as ship detection and monitoring. International co-operation is also addressed as an essential component of TOPMEX-9 Mission. This work represents a DOT Project (CONACYT-SRE 186144) contribution.

  18. Cyber Security Threats to Safety-Critical, Space-Based Infrastructures

    Science.gov (United States)

    Johnson, C. W.; Atencia Yepez, A.

    2012-01-01

    Space-based systems play an important role within national critical infrastructures. They are being integrated into advanced air-traffic management applications, rail signalling systems, energy distribution software etc. Unfortunately, the end users of communications, location sensing and timing applications often fail to understand that these infrastructures are vulnerable to a wide range of security threats. The following pages focus on concerns associated with potential cyber-attacks. These are important because future attacks may invalidate many of the safety assumptions that support the provision of critical space-based services. These safety assumptions are based on standard forms of hazard analysis that ignore cyber-security considerations This is a significant limitation when, for instance, security attacks can simultaneously exploit multiple vulnerabilities in a manner that would never occur without a deliberate enemy seeking to damage space based systems and ground infrastructures. We address this concern through the development of a combined safety and security risk assessment methodology. The aim is to identify attack scenarios that justify the allocation of additional design resources so that safety barriers can be strengthened to increase our resilience against security threats.

  19. Feature extraction algorithm for space targets based on fractal theory

    Science.gov (United States)

    Tian, Balin; Yuan, Jianping; Yue, Xiaokui; Ning, Xin

    2007-11-01

    In order to offer a potential for extending the life of satellites and reducing the launch and operating costs, satellite servicing including conducting repairs, upgrading and refueling spacecraft on-orbit become much more frequently. Future space operations can be more economically and reliably executed using machine vision systems, which can meet real time and tracking reliability requirements for image tracking of space surveillance system. Machine vision was applied to the research of relative pose for spacecrafts, the feature extraction algorithm was the basis of relative pose. In this paper fractal geometry based edge extraction algorithm which can be used in determining and tracking the relative pose of an observed satellite during proximity operations in machine vision system was presented. The method gets the gray-level image distributed by fractal dimension used the Differential Box-Counting (DBC) approach of the fractal theory to restrain the noise. After this, we detect the consecutive edge using Mathematical Morphology. The validity of the proposed method is examined by processing and analyzing images of space targets. The edge extraction method not only extracts the outline of the target, but also keeps the inner details. Meanwhile, edge extraction is only processed in moving area to reduce computation greatly. Simulation results compared edge detection using the method which presented by us with other detection methods. The results indicate that the presented algorithm is a valid method to solve the problems of relative pose for spacecrafts.

  20. Multicolor Photometric Observation of Lightning from Space: Comparison with Radio Measurements

    Science.gov (United States)

    Adachi, Toru; Cohen, Morris; Said, Ryan; Blakeslee, Richard J.; Cummer, Steven A.; Li, Jingbo; Lu, Geopeng; Hsu, Rue-Ron; Su, Han-Tzong; Chen, Alfred Bing-Chih; hide

    2011-01-01

    This study evaluates the effectiveness of spectrophotometric measurements from space in revealing properties of lightning flash. The multicolor optical waveform data obtained by FORMOSAT-2/Imager of Sprites and Upper Atmospheric Lightning (ISUAL) were analyzed in relation to National Lightning Detection Network (NLDN), North Alabama Lightning Mapping Array (LMA). As of July 2011, we found six lightning events which were observed by ISUAL and North Alabama LMA. In two of these events, NLDN showed clear positive cloud-to-ground (CG) discharges with peak current of +139.9 kA and +41.6 kA and, around that time, LMA showed continuous intra-cloud (IC) leader activities at 4-6 km altitudes. ISUAL also observed consistent optical waveforms of the IC and CG components and, interestingly, it was found that the blue/red spectral ratio clearly decreased by a factor of 1.5-2.5 at the time of CG discharges. Other four lightning events in which NLDN did not detect any CG discharges were also investigated, but such a feature was not found in any of these cases. These results suggest that the optical color of CG component is more reddish than that of IC component and we explain this as a result of more effective Rayleigh scattering in blue light emissions coming from lower-altitude light source. This finding suggests that spectral measurements could be a new useful technique to characterize ICs and CGs from space. In this talk, we will also present a result from lightning statistical analysis of ISUAL spectrophotometric data and ULF magnetic data.

  1. TanDEM-X the Earth surface observation project from space level - basis and mission status

    Directory of Open Access Journals (Sweden)

    Jerzy Wiśniowski

    2015-03-01

    Full Text Available TanDEM-X is DLR (Deutsches Zentrum für Luft- und Raumfahrt the Earth surface observation project using high-resolution SAR interferometry. It opens a new era in space borne radar remote sensing. The system is based on two satellites: TerraSAR-X (TSX and TanDEM-X (TDX flying on the very close, strictly controlled orbits. This paper gives an overview of the radar technology and overview of the TanDEM-X mission concept which is based on several innovative technologies. The primary objective of the mission is to deliver a global digital elevation model (DEM with an unprecedented accuracy, which is equal to or surpass the HRTI-3 specifications (12 m posting, relative height accuracy ±2 m for slope < 20% and ±4 m for slope > 20% [8]. Beyond that, TanDEM-X provides a highly reconfigurable platform for the demonstration of new radar imaging techniques and applications.[b]Keywords[/b]: remote sensing, Bistatic SAR, digital elevation model (DEM, Helix formation, SAR interferomery, HRTI-3, synchronization

  2. Conceptual design of jewellery: a space-based aesthetics approach

    Directory of Open Access Journals (Sweden)

    Tzintzi Vaia

    2017-01-01

    Full Text Available Conceptual design is a field that offers various aesthetic approaches to generation of nature-based product design concepts. Essentially, Conceptual Product Design (CPD uses similarities based on the geometrical forms and functionalities. Furthermore, the CAD-based freehand sketch is a primary conceptual tool in the early stages of the design process. The proposed Conceptual Product Design concept is dealing with jewelleries that are inspired from space. Specifically, a number of galaxy features, such as galaxy shapes, wormholes and graphical representation of planet magnetic field are used as inspirations. Those space-based design ideas at a conceptual level can lead to further opportunities for research and economic success of the jewellery industry. A number of illustrative case studies are presented and new opportunities can be derived for economic success.

  3. Observation of Octupole Driven Resonance Phenomena with Space Charge at the CERN Proton Synchrotron

    CERN Document Server

    Métral, E; Martini, M; Steerenberg, R; Franchetti, Giuliano; Hofmann, I

    2006-01-01

    Several benchmarking space charge experiments have been performed during the last few years in the CERN Proton Synchrotron. These controlled experiments are of paramount importance to validate the present very powerful simulation codes. The observations of the combined effect of space charge and nonlinear resonance on beam loss and emittance, using a single controllable octupole during ~ 1 s at 1.4 GeV kinetic energy, are discussed in some detail in the present paper. By lowering the working point towards the octupolar resonance, a gradual transition from a regime of loss-free core emittance blow-up to a regime of continuous loss was found.

  4. Optical/Infrared Signatures for Space-Based Remote Sensing

    National Research Council Canada - National Science Library

    Picard, R. H; Dewan, E. M; Winick, J. R; O'Neil, R. R

    2007-01-01

    This report describes work carried out under the Air Force Research Laboratory's basic research task in optical remote-sensing signatures, entitled Optical / Infrared Signatures for Space-Based Remote Sensing...

  5. Separation of atmospheric, oceanic and hydrological polar motion excitation mechanisms based on a combination of geometric and gravimetric space observations

    Science.gov (United States)

    Göttl, F.; Schmidt, M.; Seitz, F.; Bloßfeld, M.

    2015-04-01

    The goal of our study is to determine accurate time series of geophysical Earth rotation excitations to learn more about global dynamic processes in the Earth system. For this purpose, we developed an adjustment model which allows to combine precise observations from space geodetic observation systems, such as Satellite Laser Ranging (SLR), Global Navigation Satellite Systems, Very Long Baseline Interferometry, Doppler Orbit determination and Radiopositioning Integrated on Satellite, satellite altimetry and satellite gravimetry in order to separate geophysical excitation mechanisms of Earth rotation. Three polar motion time series are applied to derive the polar motion excitation functions (integral effect). Furthermore we use five time variable gravity field solutions from Gravity Recovery and Climate Experiment to determine not only the integral mass effect but also the oceanic and hydrological mass effects by applying suitable filter techniques and a land-ocean mask. For comparison the integral mass effect is also derived from degree 2 potential coefficients that are estimated from SLR observations. The oceanic mass effect is also determined from sea level anomalies observed by satellite altimetry by reducing the steric sea level anomalies derived from temperature and salinity fields of the oceans. Due to the combination of all geodetic estimated excitations the weaknesses of the individual processing strategies can be reduced and the technique-specific strengths can be accounted for. The formal errors of the adjusted geodetic solutions are smaller than the RMS differences of the geophysical model solutions. The improved excitation time series can be used to improve the geophysical modeling.

  6. Space Weather at Mars: MAVEN and MSL/RAD Observations of CME and SEP Events

    Science.gov (United States)

    Lee, C. O.; Ehresmann, B.; Lillis, R. J.; Dunn, P.; Rahmati, A.; Larson, D. E.; Guo, J.; Zeitlin, C.; Luhmann, J. G.; Halekas, J. S.; Espley, J. R.; Thiemann, E.; Hassler, D.

    2017-12-01

    While MAVEN have been observing the space weather conditions driven by ICMEs and SEPs in orbit around Mars, MSL/RAD have been measuring the surface radiation environment due to E > 150 MeV/nuc SEPs and the higher-energy galactic cosmic rays. The suite of MAVEN instruments measuring the particles (SEP), plasma (SWIA) and fields (MAG) information provides detailed local space weather information regarding the solar activity-related fluctuations in the measured surface dose rates. At the same time, the related enhancements in the RAD surface dose rates indicate the degree to which the SEPs affect the lower atmosphere and surface. We will present an overview of the MAVEN observations together with the MSL/RAD measurements and focus our discussion on a number of space weather events driven by CMEs and SEPs. During the March 2015 solar storm period, a succession of CMEs produced intense SEP proton fluxes that were detected by MAVEN/SEP in the 20 keV to 6 MeV detected energy channels. At higher energies, MAVEN/SEP record `FTO' SEP events that were triggered by > 13 MeV energetic protons passing through all three silicon detector layers (Front, Thick, and Open). Using the detector response matrix for an FTO event (incident energy vs detected energy), the minimum incident energy of the SEP protons observed in March 2015 was inferred to be > 40 MeV. The lack of any notable enhancements in the surface dose rate by MSL/RAD suggests that the highest incident energies of the SEP protons were 150 MeV SEP protons impacted the Martian atmosphere and surface. The source of the October 2015 SEP event was probably the CME that erupted near the solar west limb with respect to the Sun-Mars line. As part of the discussion, we will also show solar-heliospheric observations from near-Earth assets together with WSA-Enlil-cone results for some global heliospheric context.

  7. Estimation of the neuronal activation using fMRI data: An observer-based approach

    KAUST Repository

    Laleg-Kirati, Taous-Meriem

    2013-06-01

    This paper deals with the estimation of the neuronal activation and some unmeasured physiological information using the Blood Oxygenation Level Dependent (BOLD) signal measured using functional Magnetic Resonance Imaging (fMRI). We propose to use an observer-based approach applied to the balloon hemodynamic model. The latter describes the relation between the neural activity and the BOLD signal. The balloon model can be expressed in a nonlinear state-space representation where the states, the parameters and the input (neuronal activation), are unknown. This study focuses only on the estimation of the hidden states and the neuronal activation. The model is first linearized around the equilibrium and an observer is applied to this linearized version. Numerical results performed on synthetic data are presented.

  8. Simulations of the observation of clouds and aerosols with the Experimental Lidar in Space Equipment system.

    Science.gov (United States)

    Liu, Z; Voelger, P; Sugimoto, N

    2000-06-20

    We carried out a simulation study for the observation of clouds and aerosols with the Japanese Experimental Lidar in Space Equipment (ELISE), which is a two-wavelength backscatter lidar with three detection channels. The National Space Development Agency of Japan plans to launch the ELISE on the Mission Demonstrate Satellite 2 (MDS-2). In the simulations, the lidar return signals for the ELISE are calculated for an artificial, two-dimensional atmospheric model including different types of clouds and aerosols. The signal detection processes are simulated realistically by inclusion of various sources of noise. The lidar signals that are generated are then used as input for simulations of data analysis with inversion algorithms to investigate retrieval of the optical properties of clouds and aerosols. The results demonstrate that the ELISE can provide global data on the structures and optical properties of clouds and aerosols. We also conducted an analysis of the effects of cloud inhomogeneity on retrievals from averaged lidar profiles. We show that the effects are significant for space lidar observations of optically thick broken clouds.

  9. Observing with a space-borne gamma-ray telescope: selected results from INTEGRAL

    International Nuclear Information System (INIS)

    Schanne, Stephane

    2006-01-01

    The International Gamma-Ray Astrophysics Laboratory, i.e. the INTEGRAL satellite of ESA, in orbit since about 3 years, performs gamma-ray observations of the sky in the 15 keV to 8 MeV energy range. Thanks to its imager IBIS, and in particular the ISGRI detection plane based on 16384 CdTe pixels, it achieves an excellent angular resolution (12 arcmin) for point source studies with good continuum spectrum sensitivity. Thanks to its spectrometer SPI, based on 19 germanium detectors maintained at 85 K by a cryogenic system, located inside an active BGO veto shield, it achieves excellent spectral resolution of about 2 keV for 1 MeV photons, which permits astrophysical gamma-ray line studies with good narrow-line sensitivity. In this paper we review some goals of gamma-ray astronomy from space and present the INTEGRAL satellite, in particular its instruments ISGRI and SPI. Ground and in-flight calibration results from SPI are presented, before presenting some selected astrophysical results from INTEGRAL. In particular results on point source searches are presented, followed by results on nuclear astrophysics, exemplified by the study of the 1809 keV gamma-ray line from radioactive 26 Al nuclei produced by the ongoing stellar nucleosynthesis in the Galaxy. Finally a review on the study of the positron-electron annihilation in the Galactic center region, producing 511 keV gamma-rays, is presented

  10. A global space-based stratospheric aerosol climatology: 1979-2016

    Science.gov (United States)

    Thomason, Larry W.; Ernest, Nicholas; Millán, Luis; Rieger, Landon; Bourassa, Adam; Vernier, Jean-Paul; Manney, Gloria; Luo, Beiping; Arfeuille, Florian; Peter, Thomas

    2018-03-01

    We describe the construction of a continuous 38-year record of stratospheric aerosol optical properties. The Global Space-based Stratospheric Aerosol Climatology, or GloSSAC, provided the input data to the construction of the Climate Model Intercomparison Project stratospheric aerosol forcing data set (1979-2014) and we have extended it through 2016 following an identical process. GloSSAC focuses on the Stratospheric Aerosol and Gas Experiment (SAGE) series of instruments through mid-2005, and on the Optical Spectrograph and InfraRed Imager System (OSIRIS) and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) data thereafter. We also use data from other space instruments and from ground-based, air, and balloon borne instruments to fill in key gaps in the data set. The end result is a global and gap-free data set focused on aerosol extinction coefficient at 525 and 1020 nm and other parameters on an "as available" basis. For the primary data sets, we developed a new method for filling the post-Pinatubo eruption data gap for 1991-1993 based on data from the Cryogenic Limb Array Etalon Spectrometer. In addition, we developed a new method for populating wintertime high latitudes during the SAGE period employing a latitude-equivalent latitude conversion process that greatly improves the depiction of aerosol at high latitudes compared to earlier similar efforts. We report data in the troposphere only when and where it is available. This is primarily during the SAGE II period except for the most enhanced part of the Pinatubo period. It is likely that the upper troposphere during Pinatubo was greatly enhanced over non-volcanic periods and that domain remains substantially under-characterized. We note that aerosol levels during the OSIRIS/CALIPSO period in the lower stratosphere at mid- and high latitudes is routinely higher than what we observed during the SAGE II period. While this period had nearly continuous low-level volcanic activity, it

  11. Compressed Sensing for Space-Based High-Definition Video Technologies, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Space-based imaging sensors are important for NASA's mission in both performing scientific measurements and producing literature and documentary cinema. The recent...

  12. Space-Based Astronomy: An Educator Guide with Activities for Science, Mathematics, and Technology Education

    Science.gov (United States)

    Vogt, Gregory L.

    2001-01-01

    If you go to the country, far from city lights, you can see about 3,000 stars on a clear night. If your eyes were bigger, you could see many more stars. With a pair of binoculars, an optical device that effectively enlarges the pupil of your eye by about 30 times, the number of stars you can see increases to the tens of thousands. With a medium-sized telescope with a light-collecting mirror 30 centimeters in diameter, you can see hundreds of thousands of stars. With a large observatory telescope, millions of stars become visible. This curriculum guide uses hands-on activities to help students and teachers understand the significance of space-based astronomy--astronomical observations made from outer space. It is not intended to serve as a curriculum. Instead, teachers should select activities from this guide that support and extend existing study. The guide contains few of the traditional activities found in many astronomy guides such as constellation studies, lunar phases, and planetary orbits. It tells, rather, the story of why it is important to observe celestial objects from outer space and how to study the entire electromagnetic spectrum. Teachers are encouraged to adapt these activities for the particular needs of their students. When selected activities from this guide are used in conjunction with traditional astronomy curricula, students benefit from a more complete experience.

  13. Non-Topographic Space-Based Laser Remote Sensing

    Science.gov (United States)

    Yu, Anthony W.; Abshire, James B.; Riris, Haris; Purucker, Michael; Janches, Diego; Getty, Stephanie; Krainak, Michael A.; Stephen, Mark A.; Chen, Jeffrey R.; Li, Steve X.; hide

    2016-01-01

    In the past 20+ years, NASA Goddard Space Flight Center (GSFC) has successfully developed and flown lidars for mapping of Mars, the Earth, Mercury and the Moon. As laser and electro-optics technologies expand and mature, more sophisticated instruments that once were thought to be too complicated for space are being considered and developed. We will present progress on several new, space-based laser instruments that are being developed at GSFC. These include lidars for remote sensing of carbon dioxide and methane on Earth for carbon cycle and global climate change; sodium resonance fluorescence lidar to measure environmental parameters of the middle and upper atmosphere on Earth and Mars and a wind lidar for Mars orbit; in situ laser instruments include remote and in-situ measurements of the magnetic fields; and a time-of-flight mass spectrometer to study the diversity and structure of nonvolatile organics in solid samples on missions to outer planetary satellites and small bodies.

  14. Observer-Based Human Knee Stiffness Estimation.

    Science.gov (United States)

    Misgeld, Berno J E; Luken, Markus; Riener, Robert; Leonhardt, Steffen

    2017-05-01

    We consider the problem of stiffness estimation for the human knee joint during motion in the sagittal plane. The new stiffness estimator uses a nonlinear reduced-order biomechanical model and a body sensor network (BSN). The developed model is based on a two-dimensional knee kinematics approach to calculate the angle-dependent lever arms and the torques of the muscle-tendon-complex. To minimize errors in the knee stiffness estimation procedure that result from model uncertainties, a nonlinear observer is developed. The observer uses the electromyogram (EMG) of involved muscles as input signals and the segmental orientation as the output signal to correct the observer-internal states. Because of dominating model nonlinearities and nonsmoothness of the corresponding nonlinear functions, an unscented Kalman filter is designed to compute and update the observer feedback (Kalman) gain matrix. The observer-based stiffness estimation algorithm is subsequently evaluated in simulations and in a test bench, specifically designed to provide robotic movement support for the human knee joint. In silico and experimental validation underline the good performance of the knee stiffness estimation even in the cases of a knee stiffening due to antagonistic coactivation. We have shown the principle function of an observer-based approach to knee stiffness estimation that employs EMG signals and segmental orientation provided by our own IPANEMA BSN. The presented approach makes realtime, model-based estimation of knee stiffness with minimal instrumentation possible.

  15. Great Ellipse Route Planning Based on Space Vector

    Directory of Open Access Journals (Sweden)

    LIU Wenchao

    2015-07-01

    Full Text Available Aiming at the problem of navigation error caused by unified earth model in great circle route planning using sphere model and modern navigation equipment using ellipsoid mode, a method of great ellipse route planning based on space vector is studied. By using space vector algebra method, the vertex of great ellipse is solved directly, and description of great ellipse based on major-axis vector and minor-axis vector is presented. Then calculation formulas of great ellipse azimuth and distance are deduced using two basic vectors. Finally, algorithms of great ellipse route planning are studied, especially equal distance route planning algorithm based on Newton-Raphson(N-R method. Comparative examples show that the difference of route planning between great circle and great ellipse is significant, using algorithms of great ellipse route planning can eliminate the navigation error caused by the great circle route planning, and effectively improve the accuracy of navigation calculation.

  16. Spots and the Activity of Stars in the Hyades Cluster from Observations with the Kepler Space Telescope (K2)

    Science.gov (United States)

    Savanov, I. S.; Dmitrienko, E. S.

    2018-03-01

    Observations of the K2 mission (continuing the program of the Kepler Space Telescope) are used to estimate the spot coverage S (the fractional area of spots on the surface of an active star) for stars of the Hyades cluster. The analysis is based on data on the photometric variations of 47 confirmed single cluster members, together with their atmospheric parameters, masses, and rotation periods. The resulting values of S for these Hyades objects are lower than those stars of the Pleiades cluster (on average, by Δ S 0.05-0.06). A comparison of the results of studies of cool, low-mass dwarfs in the Hyades and Pleiades clusters, as well as the results of a study of 1570 M stars from the main field observed in the Kepler SpaceMission, indicates that the Hyades stars are more evolved than the Pleiades stars, and demonstrate lower activity. The activity of seven solar-type Hyades stars ( S = 0.013 ± 0.006) almost approaches the activity level of the present-day Sun, and is lower than the activity of solar-mass stars in the Pleiades ( S = 0.031 ± 0.003). Solar-type stars in the Hyades rotate faster than the Sun ( = 8.6 d ), but slower than similar Pleiades stars.

  17. Space Launch System Base Heating Test: Experimental Operations & Results

    Science.gov (United States)

    Dufrene, Aaron; Mehta, Manish; MacLean, Matthew; Seaford, Mark; Holden, Michael

    2016-01-01

    NASA's Space Launch System (SLS) uses four clustered liquid rocket engines along with two solid rocket boosters. The interaction between all six rocket exhaust plumes will produce a complex and severe thermal environment in the base of the vehicle. This work focuses on a recent 2% scale, hot-fire SLS base heating test. These base heating tests are short-duration tests executed with chamber pressures near the full-scale values with gaseous hydrogen/oxygen engines and RSRMV analogous solid propellant motors. The LENS II shock tunnel/Ludwieg tube tunnel was used at or near flight duplicated conditions up to Mach 5. Model development was based on the Space Shuttle base heating tests with several improvements including doubling of the maximum chamber pressures and duplication of freestream conditions. Test methodology and conditions are presented, and base heating results from 76 runs are reported in non-dimensional form. Regions of high heating are identified and comparisons of various configuration and conditions are highlighted. Base pressure and radiometer results are also reported.

  18. A prospective observational study of skin to subarachnoid space depth in the Indian population

    Directory of Open Access Journals (Sweden)

    Smita Prakash

    2014-01-01

    Full Text Available Background and Aims: A pre-puncture estimate of skin to subarachnoid space depth (SSD may guide spinal needle placement and reduce complications associated with lumbar puncture. Our aim was to determine (1 The SSD in Indian males, females, parturients and the overall population; (2 To derive formulae for predicting SSD and (3 To determine which previously suggested formula best suited our population. Methods: In this prospective, observational study, 800 adult Indian patients undergoing surgery under spinal anaesthesia were divided into three groups: Males (Group M, females (Group F and parturients (Group PF. SSD was measured after lumbar puncture. The relationship between SSD and patient characteristics was studied and statistical models were used to derive formula for predicting SSD. Statistical analysis included One-way ANOVA with post hoc analysis, forward stepwise multivariate regression analysis and paired t-tests. Results: Mean SSD was 4.71 ± 0.70 cm in the overall population. SSD in adult males (4.81 ± 0.68 cm was significantly longer than that observed in females (4.55 ± 0.66 cm but was comparable with SSD in parturients (4.73 ± 0.73 cm. Formula for predicting SSD in the overall population was 2.71 + 0.09 × Body Mass Index (BMI. Stocker′s formula when applied correlated best with the observed SSD. Formulae were derived for the three groups. Conclusions: We found gender-based differences in SSD, with SSD in males being significantly greater than that observed in the female population. SSD correlated with BMI in the parturient and the overall population. Amongst the previously proposed formulae, Stocker′s formula was most accurate in predicting SSD in our population.

  19. An optical flow-based state-space model of the vocal folds

    DEFF Research Database (Denmark)

    Granados, Alba; Brunskog, Jonas

    2017-01-01

    High-speed movies of the vocal fold vibration are valuable data to reveal vocal fold features for voice pathology diagnosis. This work presents a suitable Bayesian model and a purely theoretical discussion for further development of a framework for continuum biomechanical features estimation. A l...... to capture different deformation patterns between the computed optical flow and the finite element deformation, controlled by the choice of the model tissue parameters........ A linear and Gaussian nonstationary state-space model is proposed and thoroughly discussed. The evolution model is based on a self-sustained three-dimensional finite element model of the vocal folds, and the observation model involves a dense optical flow algorithm. The results show that the method is able...

  20. An optical flow-based state-space model of the vocal folds.

    Science.gov (United States)

    Granados, Alba; Brunskog, Jonas

    2017-06-01

    High-speed movies of the vocal fold vibration are valuable data to reveal vocal fold features for voice pathology diagnosis. This work presents a suitable Bayesian model and a purely theoretical discussion for further development of a framework for continuum biomechanical features estimation. A linear and Gaussian nonstationary state-space model is proposed and thoroughly discussed. The evolution model is based on a self-sustained three-dimensional finite element model of the vocal folds, and the observation model involves a dense optical flow algorithm. The results show that the method is able to capture different deformation patterns between the computed optical flow and the finite element deformation, controlled by the choice of the model tissue parameters.

  1. Reaping the space investment. [Shuttle era geosynchronous satellite based technological trends

    Science.gov (United States)

    Calio, A. J.

    1979-01-01

    By 1999 operational space systems will be implemented routinely on a worldwide scale in many areas vital to human survival and life quality. Geosynchronous-based monitoring and observation will be extensively used. The Shuttle era will bring in the capability to allow monitoring and identifying pollution sources which fail to stay within required limits. Remotely sensed data over land masses will provide needed facts on renewable and nonrenewable earth resources. New instruments and techniques will have been developed to provide geologists with clues to the declining number of deposits of fuels and minerals. Also, practical methods for predicting earthquakes will have been elaborated by 1999. Communications will see implementation of many of the technological goals of 1978.

  2. Solar origins of space weather and space climate

    CERN Document Server

    Komm, Rudolf; Pevtsov, Alexei; Leibacher, John

    2014-01-01

    This topical issue is based on the presentations given at the 26th National Solar Observatory (NSO) Summer Workshop held at the National Solar Observatory/Sacramento Peak, New Mexico, USA from 30 April to 4 May 2012. This unique forum brought together experts in different areas of solar and space physics to help in developing a full picture of the origin of solar phenomena that affect Earth’s technological systems.  The articles include theory, model, and observation research on the origin of the solar activity and its cycle, as well as a discussion on how to incorporate the research into space-weather forecasting tools.  This volume is aimed at graduate students and researchers active in solar physics and space science.  Previously published in Solar Physics, Vol. 289/2, 2014.

  3. Space-based gravitational-wave detectors can determine the thermal history of the early Universe

    International Nuclear Information System (INIS)

    Nakayama, Kazunori; Saito, Shun; Suwa, Yudai; Yokoyama, Jun'ichi

    2008-01-01

    It is shown that space-based gravitational-wave detectors such as DECIGO and/or the Big Bang Observer will provide us with invaluable information on the cosmic thermal history after inflation, and they will be able to determine the reheat temperature T R provided that it lies in the range preferred by the cosmological gravitino problem, T R ∼10 5-9 GeV. Therefore it is strongly desired that they will be put into practice as soon as possible

  4. Advanced fire observation by the Intelligent Infrared Sensor prototype FOCUS on the International Space Station

    Science.gov (United States)

    Oertel, D.; Haschberger, P.; Tank, V.; Lanzl, F.; Zhukov, B.; Jahn, H.; Briess, K.; Lorenz, E.; Roeser, H.-P.; Ginati, A.; Tobehn, C.; Schulte in den Bäumen, J.; Christmann, U.

    1999-01-01

    Current and planned operational space-borne Earth observation systems provide spatially, radiometrically or temporally crude data for the detection and monitoring of high temperature phenomena on the surface of our planet. High Temperature Events (HTE) very often cause environmental disasters. Such HTE are forest and savannah fires, fires of open coal mines, volcanic activities and others (e.g. fires of oil wells, pipelines etc.). A simultaneous co-registration of a combination of infrared (IR) and visible (VIS) channels is the key for a reliable autonomous on-board detection of High Temperature Events (HTE) on Earth surface, such as vegetation fires and volcano eruptions. This is the main feature of the FOCUS experiment. Furthermore there are ecology-oriented objectives of the FOCUS experiment mainly related to spectrometric/imaging remote inspection and parameter extraction of selected HTEs, and to the assessment of some ecological consequences of HTEs, such as aerosol and gas emission. Based on own experimental work and supported by Co-Investigators from Italy, Greece, France, Spain, Russia and Germany, DLR proposed in 1997 to use the International Space Station (ISS) in its early utilization phase as a platform and test-bed for an Intelligent Infrared Sensor prototype FOCUS of a future Environmental Disaster Recognition Satellite System. FOCUS is considered by ESA as an important mission combining a number of proven technologies and observation techniques to provide the scientific and operational user community with key data for the classification and monitoring of forest fires. FOCUS was selected as one of five European ``Groupings'' to be flown as an externally mounted payload during the early utilisation phase of the ISS. The FOCUS Phase A Study will be performed by OHB-System, DLR and Zeiss from September 1998 until May 1999.

  5. Observation and simulation of space-charge effects in a radio-frequency photoinjector using a transverse multibeamlet distribution

    Directory of Open Access Journals (Sweden)

    M. Rihaoui

    2009-12-01

    Full Text Available We report on an experimental study of space-charge effects in a radio-frequency (rf photoinjector. A 5 MeV electron bunch, consisting of a number of beamlets separated transversely, was generated in an rf photocathode gun and propagated in the succeeding drift space. The collective interaction of these beamlets was studied for different experimental conditions. The experiment allowed the exploration of space-charge effects and its comparison with 3D particle-in-cell simulations. Our observations also suggest the possible use of a multibeam configuration to tailor the transverse distribution of an electron beam.

  6. Time biases in laser ranging observations: A concerning issue of Space Geodesy

    Science.gov (United States)

    Exertier, Pierre; Belli, A.; Lemoine, J. M.

    2017-09-01

    Time transfer by Laser Ranging (LR) recently demonstrated a remarkable stability (a few ps over ∼1000 s) and accuracy (synchronizing both space and ground clocks over distances from a few thousands to tens of thousands kilometers. Given its potential role in navigation, fundamental physics and metrology, it is crucial that synergy between laser ranging and Time&Frequency (T/F) technologies improves to meet the present and future space geodesy requirements. In this article, we examine the behavior of T/F systems that are used in LR tracking stations of the international laser ranging service. The approach we investigate is to compute time synchronization between clocks used at LR stations using accurate data of the Time Transfer by Laser Link (T2L2) experiment onboard the satellite Jason-2 (Samain et al., 2014). Systematic time biases are estimated against the UTC time scale for a set of 22 observing stations in 2013, in the range of zero to a few μ s. Our results suggest that the ILRS network suffers from accuracy issues, due to time biases in the laser ranging observations. We discuss how these systematic effects impact the precise orbit determination of LAGEOS geodetic satellites over a 1-year analysis, and additionally give a measure of the local effect into station coordinates, regarding in particular the effect in the east-west component that is of 2-6 mm for a typical systematic time bias of one μ s.

  7. Control of variable speed variable pitch wind turbine based on a disturbance observer

    Science.gov (United States)

    Ren, Haijun; Lei, Xin

    2017-11-01

    In this paper, a novel sliding mode controller based on disturbance observer (DOB) to optimize the efficiency of variable speed variable pitch (VSVP) wind turbine is developed and analyzed. Due to the highly nonlinearity of the VSVP system, the model is linearly processed to obtain the state space model of the system. Then, a conventional sliding mode controller is designed and a DOB is added to estimate wind speed. The proposed control strategy can successfully deal with the random nature of wind speed, the nonlinearity of VSVP system, the uncertainty of parameters and external disturbance. Via adding the observer to the sliding mode controller, it can greatly reduce the chattering produced by the sliding mode switching gain. The simulation results show that the proposed control system has the effectiveness and robustness.

  8. Observations of the orbital debris complex by the Midcourse Space Experiment (MSX) satellite

    Science.gov (United States)

    Vilas, Faith; Anz-Meador, Phillip; Talent, Dave

    1997-01-01

    The midcourse space experiment (MSX) provides the opportunity to observe debris at multiple, simultaneous wavelengths, or in conjunction with other sensors and prior data sets. The instruments onboard MSX include an infrared telescope, an infrared interferometer, a visible telescope, an ultraviolet telescope and a spectroscopic imager. The spacecraft carries calibration spheres for instrument calibration and atmospheric drag studies. The experimental program, the implementation aspects, the data reduction techniques and the preliminary results are described.

  9. Near-Space TOPSAR Large-Scene Full-Aperture Imaging Scheme Based on Two-Step Processing

    Directory of Open Access Journals (Sweden)

    Qianghui Zhang

    2016-07-01

    Full Text Available Free of the constraints of orbit mechanisms, weather conditions and minimum antenna area, synthetic aperture radar (SAR equipped on near-space platform is more suitable for sustained large-scene imaging compared with the spaceborne and airborne counterparts. Terrain observation by progressive scans (TOPS, which is a novel wide-swath imaging mode and allows the beam of SAR to scan along the azimuth, can reduce the time of echo acquisition for large scene. Thus, near-space TOPS-mode SAR (NS-TOPSAR provides a new opportunity for sustained large-scene imaging. An efficient full-aperture imaging scheme for NS-TOPSAR is proposed in this paper. In this scheme, firstly, two-step processing (TSP is adopted to eliminate the Doppler aliasing of the echo. Then, the data is focused in two-dimensional frequency domain (FD based on Stolt interpolation. Finally, a modified TSP (MTSP is performed to remove the azimuth aliasing. Simulations are presented to demonstrate the validity of the proposed imaging scheme for near-space large-scene imaging application.

  10. Sparsity-Based Space-Time Adaptive Processing Using OFDM Radar

    Energy Technology Data Exchange (ETDEWEB)

    Sen, Satyabrata [ORNL

    2012-01-01

    We propose a sparsity-based space-time adaptive processing (STAP) algorithm to detect a slowly-moving target using an orthogonal frequency division multiplexing (OFDM) radar. We observe that the target and interference spectra are inherently sparse in the spatio-temporal domain, and hence we exploit that sparsity to develop an efficient STAP technique. In addition, the use of an OFDM signal increases the frequency diversity of our system, as different scattering centers of a target resonate at different frequencies, and thus improves the target detectability. First, we formulate a realistic sparse-measurement model for an OFDM radar considering both the clutter and jammer as the interfering sources. Then, we show that the optimal STAP-filter weight-vector is equal to the generalized eigenvector corresponding to the minimum generalized eigenvalue of the interference and target covariance matrices. To estimate the target and interference covariance matrices, we apply a residual sparse-recovery technique that enables us to incorporate the partially known support of the sparse vector. Our numerical results demonstrate that the sparsity-based STAP algorithm, with considerably lesser number of secondary data, produces an equivalent performance as the other existing STAP techniques.

  11. Movement-based interaction in camera spaces: a conceptual framework

    DEFF Research Database (Denmark)

    Eriksson, Eva; Hansen, Thomas Riisgaard; Lykke-Olesen, Andreas

    2007-01-01

    In this paper we present three concepts that address movement-based interaction using camera tracking. Based on our work with several movementbased projects we present four selected applications, and use these applications to leverage our discussion, and to describe our three main concepts space,...

  12. On projective invariants based on non-linear connections in a Finsler space I

    International Nuclear Information System (INIS)

    Rastogi, S.C.

    1986-05-01

    The projective transformations based on linear connections in a Finsler space have been studied by Berwald, Misra, Szabo, Matsumoto, Fukai and Yamada, Rastogi and others. In almost all these papers the emphasis has been on studying Finsler spaces of scalar curvature, Finsler spaces of constant curvature and Finsler spaces of zero curvature with the help of projective curvature tensors of Weyl and Douglas. In 1981, the author studied projective transformation in a Finsler space based on non-linear connections and obtained certain projective invariants. The aim of the present paper is to study Finsler spaces of scalar curvature, constant curvature and zero curvature with the help of non-linear connections and projective invariants obtained from non-linear connections. (author)

  13. Novel Space-based Solar Power Technologies and Architectures for Earth and Beyond

    Science.gov (United States)

    Howell, Joe T.; Fikes, John C.; O'Neill, Mark J.

    2005-01-01

    Research, development and studies of novel space-based solar power systems, technologies and architectures for Earth and beyond are needed to reduce the cost of clean electrical power for terrestrial use and to provide a stepping stone for providing an abundance of power in space, i.e., manufacturing facilities, tourist facilities, delivery of power between objects in space, and between space and surface sites. The architectures, technologies and systems needed for space to Earth applications may also be used for in-space applications. Advances in key technologies, i.e., power generation, power management and distribution, power beaming and conversion of beamed power are needed to achieve the objectives of both terrestrial and extraterrestrial applications. Power beaming or wireless power transmission (WPT) can involve lasers or microwaves along with the associated power interfaces. Microwave and laser transmission techniques have been studied with several promising approaches to safe and efficient WPT identified. These investigations have included microwave phased array transmitters, as well as laser transmission and associated optics. There is a need to produce "proof-of-concept" validation of critical WPT technologies for both the near-term, as well as far-term applications. Investments may be harvested in near-term beam safe demonstrations of commercial WPT applications. Receiving sites (users) include ground-based stations for terrestrial electrical power, orbital sites to provide power for satellites and other platforms, future space elevator systems, space vehicle propulsion, and space to surface sites. This paper briefly discusses achieving a promising approach to the solar power generation and beamed power conversion. The approach is based on a unique high-power solar concentrator array called Stretched Lens Array (SLA) for both solar power generation and beamed power conversion. Since both versions (solar and laser) of SLA use many identical components

  14. Development of 4D mathematical observer models for the task-based evaluation of gated myocardial perfusion SPECT

    Science.gov (United States)

    Lee, Taek-Soo; Frey, Eric C.; Tsui, Benjamin M. W.

    2015-04-01

    This paper presents two 4D mathematical observer models for the detection of motion defects in 4D gated medical images. Their performance was compared with results from human observers in detecting a regional motion abnormality in simulated 4D gated myocardial perfusion (MP) SPECT images. The first 4D mathematical observer model extends the conventional channelized Hotelling observer (CHO) based on a set of 2D spatial channels and the second is a proposed model that uses a set of 4D space-time channels. Simulated projection data were generated using the 4D NURBS-based cardiac-torso (NCAT) phantom with 16 gates/cardiac cycle. The activity distribution modelled uptake of 99mTc MIBI with normal perfusion and a regional wall motion defect. An analytical projector was used in the simulation and the filtered backprojection (FBP) algorithm was used in image reconstruction followed by spatial and temporal low-pass filtering with various cut-off frequencies. Then, we extracted 2D image slices from each time frame and reorganized them into a set of cine images. For the first model, we applied 2D spatial channels to the cine images and generated a set of feature vectors that were stacked for the images from different slices of the heart. The process was repeated for each of the 1,024 noise realizations, and CHO and receiver operating characteristics (ROC) analysis methodologies were applied to the ensemble of the feature vectors to compute areas under the ROC curves (AUCs). For the second model, a set of 4D space-time channels was developed and applied to the sets of cine images to produce space-time feature vectors to which the CHO methodology was applied. The AUC values of the second model showed better agreement (Spearman’s rank correlation (SRC) coefficient = 0.8) to human observer results than those from the first model (SRC coefficient = 0.4). The agreement with human observers indicates the proposed 4D mathematical observer model provides a good predictor of the

  15. Development of 4D mathematical observer models for the task-based evaluation of gated myocardial perfusion SPECT

    International Nuclear Information System (INIS)

    Lee, Taek-Soo; Frey, Eric C; Tsui, Benjamin M W

    2015-01-01

    This paper presents two 4D mathematical observer models for the detection of motion defects in 4D gated medical images. Their performance was compared with results from human observers in detecting a regional motion abnormality in simulated 4D gated myocardial perfusion (MP) SPECT images. The first 4D mathematical observer model extends the conventional channelized Hotelling observer (CHO) based on a set of 2D spatial channels and the second is a proposed model that uses a set of 4D space-time channels. Simulated projection data were generated using the 4D NURBS-based cardiac-torso (NCAT) phantom with 16 gates/cardiac cycle. The activity distribution modelled uptake of 99m Tc MIBI with normal perfusion and a regional wall motion defect. An analytical projector was used in the simulation and the filtered backprojection (FBP) algorithm was used in image reconstruction followed by spatial and temporal low-pass filtering with various cut-off frequencies. Then, we extracted 2D image slices from each time frame and reorganized them into a set of cine images. For the first model, we applied 2D spatial channels to the cine images and generated a set of feature vectors that were stacked for the images from different slices of the heart. The process was repeated for each of the 1,024 noise realizations, and CHO and receiver operating characteristics (ROC) analysis methodologies were applied to the ensemble of the feature vectors to compute areas under the ROC curves (AUCs). For the second model, a set of 4D space-time channels was developed and applied to the sets of cine images to produce space-time feature vectors to which the CHO methodology was applied. The AUC values of the second model showed better agreement (Spearman’s rank correlation (SRC) coefficient = 0.8) to human observer results than those from the first model (SRC coefficient = 0.4). The agreement with human observers indicates the proposed 4D mathematical observer model provides a good predictor of the

  16. A Simulation Base Investigation of High Latency Space Systems Operations

    Science.gov (United States)

    Li, Zu Qun; Crues, Edwin Z.; Bielski, Paul; Moore, Michael

    2017-01-01

    NASA's human space program has developed considerable experience with near Earth space operations. Although NASA has experience with deep space robotic missions, NASA has little substantive experience with human deep space operations. Even in the Apollo program, the missions lasted only a few weeks and the communication latencies were on the order of seconds. Human missions beyond the relatively close confines of the Earth-Moon system will involve missions with durations measured in months and communications latencies measured in minutes. To minimize crew risk and to maximize mission success, NASA needs to develop a better understanding of the implications of these types of mission durations and communication latencies on vehicle design, mission design and flight controller interaction with the crew. To begin to address these needs, NASA performed a study using a physics-based subsystem simulation to investigate the interactions between spacecraft crew and a ground-based mission control center for vehicle subsystem operations across long communication delays. The simulation, built with a subsystem modeling tool developed at NASA's Johnson Space Center, models the life support system of a Mars transit vehicle. The simulation contains models of the cabin atmosphere and pressure control system, electrical power system, drinking and waste water systems, internal and external thermal control systems, and crew metabolic functions. The simulation has three interfaces: 1) a real-time crew interface that can be use to monitor and control the vehicle subsystems; 2) a mission control center interface with data transport delays up to 15 minutes each way; 3) a real-time simulation test conductor interface that can be use to insert subsystem malfunctions and observe the interactions between the crew, ground, and simulated vehicle. The study was conducted at the 21st NASA Extreme Environment Mission Operations (NEEMO) mission between July 18th and Aug 3rd of year 2016. The NEEMO

  17. The Space Station as a Construction Base for Large Space Structures

    Science.gov (United States)

    Gates, R. M.

    1985-01-01

    The feasibility of using the Space Station as a construction site for large space structures is examined. An overview is presented of the results of a program entitled Definition of Technology Development Missions (TDM's) for Early Space Stations - Large Space Structures. The definition of LSS technology development missions must be responsive to the needs of future space missions which require large space structures. Long range plans for space were assembled by reviewing Space System Technology Models (SSTM) and other published sources. Those missions which will use large space structures were reviewed to determine the objectives which must be demonstrated by technology development missions. The three TDM's defined during this study are: (1) a construction storage/hangar facility; (2) a passive microwave radiometer; and (3) a precision optical system.

  18. Mission planning for space based satellite surveillance experiments with the MSX

    Science.gov (United States)

    Sridharan, R.; Fishman, T.; Robinson, E.; Viggh, H.; Wiseman, A.

    1994-01-01

    The Midcourse Space Experiment is a BMDO-sponsored scientific satellite set for launch within the year. The satellite will collect phenomenology data on missile targets, plumes, earth limb backgrounds and deep space backgrounds in the LWIR, visible and ultra-violet spectral bands. It will also conduct functional demonstrations for space-based space surveillance. The Space-Based Visible sensor, built by Lincoln Laboratory, Massachusetts Institute of Technology, is the primary sensor on board the MSX for demonstration of space surveillance. The SBV Processing, Operations and Control Center (SPOCC) is the mission planning and commanding center for all space surveillance experiments using the SBV and other MSX instruments. The guiding principle in the SPOCC Mission Planning System was that all routine functions be automated. Manual analyst input should be minimal. Major concepts are: (I) A high level language, called SLED, for user interface to the system; (2) A group of independent software processes which would generally be run in a pipe-line mode for experiment commanding but can be run independently for analyst assessment; (3) An integrated experiment cost computation function that permits assessment of the feasibility of the experiment. This paper will report on the design, implementation and testing of the Mission Planning System.

  19. Design of Urban Public Spaces: Intent vs. Reality

    Directory of Open Access Journals (Sweden)

    Mikkel Hjort

    2018-04-01

    Full Text Available This study investigated how two public spaces for sport and recreation were utilized by different user groups, and how this aligned with the initial design objectives for these spaces. Two newly built urban spaces situated in Copenhagen, Denmark, provided the context for this investigation. The System for Observing Play and Recreation in Communities (SOPARC was used to examine the physical activity of users in these two urban spaces. The architects responsible for designing each space were interviewed to ascertain the intended target group of each space and to unravel the reasons behind the design decisions. The SOPARC observations revealed that males were more vigorously active than females when using the recreation facilities, and the observed users did not align with the intended target groups. The interviews suggested that design decisions were based on minimal interdisciplinary knowledge, and that expert knowledge was chosen randomly. These findings point to a systematic lack of evidence-based practice when designing sport and recreational facilities. This article has implications for landscape architects and urban planners; a new method must be developed to embed interdisciplinary knowledge in the planning process of future sport and recreation projects. This must be done in a systematic way to make the design process transparent.

  20. New Designs of Reduced-Order Observer-Based Controllers for Singularly Perturbed Linear Systems

    Directory of Open Access Journals (Sweden)

    Heonjong Yoo

    2017-01-01

    Full Text Available The slow and fast reduced-order observers and reduced-order observer-based controllers are designed by using the two-stage feedback design technique for slow and fast subsystems. The new designs produce an arbitrary order of accuracy, while the previously known designs produce the accuracy of O(ϵ only where ϵ is a small singular perturbation parameter. Several cases of reduced-order observer designs are considered depending on the measured state space variables: only all slow variables are measured, only all fast variables are measured, and some combinations of the slow and fast variables are measured. Since the two-stage methods have been used to overcome the numerical ill-conditioning problem for Cases (III–(V, they have similar procedures. The numerical ill-conditioning problem is avoided so that independent feedback controllers can be applied to each subsystem. The design allows complete time-scale separation for both the reduced-order observer and controller through the complete and exact decomposition into slow and fast time scales. This method reduces both offline and online computations.

  1. METHOD OF IMAGE QUALITY ENHANCEMENT FOR SPACE OBJECTS

    Directory of Open Access Journals (Sweden)

    D. S. Korshunov

    2014-07-01

    Full Text Available The paper deals with an approach for image quality improvement of the space objects in the visible range of electromagnetic wave spectrum. The proposed method is based on the joint taking into account of both the motion velocity of the space supervisory apparatus and a space object observed in the near-earth space when the time of photo-detector exposure is chosen. The timing of exposure is carried out by light-signal characteristics, which determines the optimal value of the charge package formed in the charge-coupled device being irradiated. Thus, the parameters of onboard observation equipment can be selected, which provides space images suitable for interpretation. The linear resolving capacity is used as quality indicator for space images, giving a complete picture for the image contrast and geometric properties of the object on the photo. Observation scenario modeling of the space object, done by sputnik-inspector, has shown the possibility of increasing the linear resolution up to10% - 20% or up to 40% - 50% depending on the non-complanarity angle at the movement along orbits. The proposed approach to the increase of photographs quality provides getting sharp and highcontrast images of space objects by the optical-electronic equipment of the space-based remote sensing. The usage of these images makes it possible to detect in time the space technology failures, which are the result of its exploitation in the nearearth space. The proposed method can be also applied at the stage of space systems design for optical-electronic surveillance in computer models used for facilities assessment of the shooting equipment information tract.

  2. Cosmological observations with a wide field telescope in space: Pixel simulations of EUCLID spectrometer

    International Nuclear Information System (INIS)

    Zoubian, Julien

    2012-01-01

    The observations of the supernovae, the cosmic microwave background, and more recently the measurement of baryon acoustic oscillations and the weak lensing effects, converge to a Lambda CDM model, with an accelerating expansion of the today Universe. This model need two dark components to fit the observations, the dark matter and the dark energy. Two approaches seem particularly promising to measure both geometry of the Universe and growth of dark matter structures, the analysis of the weak distortions of distant galaxies by gravitational lensing and the study of the baryon acoustic oscillations. Both methods required a very large sky surveys of several thousand square degrees. In the context of the spectroscopic survey of the space mission EUCLID, dedicated to the study of the dark side of the universe, I developed a pixel simulation tool for analyzing instrumental performances. The proposed method can be summarized in three steps. The first step is to simulate the observables, i.e. mainly the sources of the sky. I work up a new method, adapted for spectroscopic simulations, which allows to mock an existing survey of galaxies in ensuring that the distribution of the spectral properties of galaxies are representative of current observations, in particular the distribution of the emission lines. The second step is to simulate the instrument and produce images which are equivalent to the expected real images. Based on the pixel simulator of the HST, I developed a new tool to compute the images of the spectroscopic channel of EUCLID. The new simulator have the particularity to be able to simulate PSF with various energy distributions and detectors which have different pixels. The last step is the estimation of the performances of the instrument. Based on existing tools, I set up a pipeline of image processing and performances measurement. My main results were: 1) to validate the method by simulating an existing survey of galaxies, the WISP survey, 2) to determine the

  3. Observing the Anthropocene from Space: Challenges and Needs

    Science.gov (United States)

    Burrows, John

    2016-07-01

    The rapid growth of human population since the industrial revolution has been coupled with a much increased standard of living and bountiful production of food. The dominant energy source sustaining this development has been fossil fuel combustion. However this has resulted in pollution which now spans all scales. There have significant impacts on air quality, water quality, stratospheric ozone and climate. The impacts can sudden and large and also slowly accumulate over time in the long term. The first decades of the space age resulted in pioneering efforts to establish adequate measurement capability. This process is continuing to evolve. Over the past two decades there have been a number of efforts to define the contribution and needs for a space segment which can separate anthropogenic form natural changes in the earth system. This talk introduces this topic of the use of the space segment to deconvolve change from anthropogenic activity and natural phenomena.

  4. SETH: A Hierarchical, Agent-based Architecture for Smart Spaces

    OpenAIRE

    Marsá Maestre, Iván

    2008-01-01

    The ultimate goal of any smart environment is to release users from the tasks they usually perform to achieve comfort, efficiency, and service personalization. To achieve this goal, we propose to use multiagent systems. In this report we describe the SETH architectur: a hierarchical, agent-based solution intended to be applicable to different smart space scenarios, ranging from small environments, like smart homes or smart offices, to large smart spaces like cities.

  5. Non-sky-averaged sensitivity curves for space-based gravitational-wave observatories

    International Nuclear Information System (INIS)

    Vallisneri, Michele; Galley, Chad R

    2012-01-01

    The signal-to-noise ratio (SNR) is used in gravitational-wave observations as the basic figure of merit for detection confidence and, together with the Fisher matrix, for the amount of physical information that can be extracted from a detected signal. SNRs are usually computed from a sensitivity curve, which describes the gravitational-wave amplitude needed by a monochromatic source of given frequency to achieve a threshold SNR. Although the term 'sensitivity' is used loosely to refer to the detector's noise spectral density, the two quantities are not the same: the sensitivity includes also the frequency- and orientation-dependent response of the detector to gravitational waves and takes into account the duration of observation. For interferometric space-based detectors similar to LISA, which are sensitive to long-lived signals and have constantly changing position and orientation, exact SNRs need to be computed on a source-by-source basis. For convenience, most authors prefer to work with sky-averaged sensitivities, accepting inaccurate SNRs for individual sources and giving up control over the statistical distribution of SNRs for source populations. In this paper, we describe a straightforward end-to-end recipe to compute the non-sky-averaged sensitivity of interferometric space-based detectors of any geometry. This recipe includes the effects of spacecraft motion and of seasonal variations in the partially subtracted confusion foreground from Galactic binaries, and it can be used to generate a sampling distribution of sensitivities for a given source population. In effect, we derive error bars for the sky-averaged sensitivity curve, which provide a stringent statistical interpretation for previously unqualified statements about sky-averaged SNRs. As a worked-out example, we consider isotropic and Galactic-disk populations of monochromatic sources, as observed with the 'classic LISA' configuration. We confirm that the (standard) inverse-rms average sensitivity

  6. Study of the galactic centre region in the soft γ ray domain from the observations performed by the space telescope SIGMA

    International Nuclear Information System (INIS)

    Cordier, Bertrand

    1992-01-01

    This research thesis reports the detailed presentation of the SIGMA telescope, and its use for the observation of the galactic centre region. The SIGMA (gamma imagery system with random mask) telescope is based on an imagery technique using a coded aperture mask, and comprises three main components: the code-mask which modulates information and defines the experiment angular resolution, a position detector which provides the coordinates of the point of interaction of photons and their energy, and allows images to be built up, and active and passive shielding to reduce the background noise. The telescope operating modes and performance (space resolution, angular resolution, camera energy response, sensitivity) are presented. The data reduction procedure is described. Then, the author presents the Galaxy centre, discusses previous observations, and reports and comments new observations performed by using SIGMA [fr

  7. A distributed data base management system. [for Deep Space Network

    Science.gov (United States)

    Bryan, A. I.

    1975-01-01

    Major system design features of a distributed data management system for the NASA Deep Space Network (DSN) designed for continuous two-way deep space communications are described. The reasons for which the distributed data base utilizing third-generation minicomputers is selected as the optimum approach for the DSN are threefold: (1) with a distributed master data base, valid data is available in real-time to support DSN management activities at each location; (2) data base integrity is the responsibility of local management; and (3) the data acquisition/distribution and processing power of a third-generation computer enables the computer to function successfully as a data handler or as an on-line process controller. The concept of the distributed data base is discussed along with the software, data base integrity, and hardware used. The data analysis/update constraint is examined.

  8. Phase space properties of local observables and structure of scaling limits

    International Nuclear Information System (INIS)

    Buchholz, D.

    1995-05-01

    For any given algebra of local observables in relativistic quantum field theory there exists an associated scaling algebra which permits one to introduce renormalization group transformations and to construct the scaling (short distance) limit of the theory. On the basis of this result it is discussed how the phase space properties of a theory determine the structure of its scaling limit. Bounds on the number of local degrees of freedom appearing in the scaling limit are given which allow one to distinguish between theories with classical and quantum scaling limits. The results can also be used to establish physically significant algebraic properties of the scaling limit theories, such as the split property. (orig.)

  9. Space debris removal using a high-power ground-based laser

    Energy Technology Data Exchange (ETDEWEB)

    Monroe, D.K.

    1993-12-31

    The feasibility and practicality of using a ground-based laser (GBL) to remove artificial space debris is examined. Physical constraints indicate that a reactor-pumped laser (RPL) may be best suited for this mission, because of its capabilities for multimegawatt output long run-times, and near-diffraction-limited initial beams. Simulations of a laser-powered debris removal system indicate that a 5-MW RPL with a 10-meter-diameter beam director and adaptive optics capabilities can deorbit 1-kg debris from space station altitudes. Larger debris can be deorbited or transferred to safer orbits after multiple laser engagements. A ground-based laser system may be the only realistic way to access and remove some 10,000 separate objects, having velocities in the neighborhood of 7 km/sec, and being spatially distributed over some 10{sup 10} km{sup 3} of space.

  10. Augmenting the Funding Sources for Space Science and the ASTRO-1 Space Telescope

    Science.gov (United States)

    Morse, Jon

    2015-08-01

    The BoldlyGo Institute was formed in 2013 to augment the planned space science portfolio through philanthropically funded robotic space missions, similar to how some U.S. medical institutes and ground-based telescopes are funded. I introduce BoldlyGo's two current projects: the SCIM mission to Mars and the ASTRO-1 space telescope. In particular, ASTRO-1 is a 1.8-meter off-axis (unobscured) ultraviolet-visible space observatory to be located in a Lagrange point or heliocentric orbit with a wide-field panchromatic camera, medium- and high-resolution spectrograph, and high-contrast imaging coronagraph and/or an accompanying starshade/occulter. It is intended for the post-Hubble Space Telescope era in the 2020s, enabling unique measurements of a broad range of celestial targets, while providing vital complementary capabilities to other ground- and space-based facilities such as the JWST, ALMA, WFIRST-AFTA, LSST, TESS, Euclid, and PLATO. The ASTRO-1 architecture simultaneously wields great scientific power while being technically viable and affordable. A wide variety of scientific programs can be accomplished, addressing topics across space astronomy, astrophysics, fundamental physics, and solar system science, as well as being technologically informative to future large-aperture programs. ASTRO-1 is intended to be a new-generation research facility serving a broad national and international community, as well as a vessel for impactful public engagement. Traditional institutional partnerships and consortia, such as are common with private ground-based observatories, may play a role in the support and governance of ASTRO-1; we are currently engaging interested international organizations. In addition to our planned open guest observer program and accessible data archive, we intend to provide a mechanism whereby individual scientists can buy in to a fraction of the gauranteed observing time. Our next step in ASTRO-1 development is to form the ASTRO-1 Requirements Team

  11. Update on the Worsening Particle Radiation Environment Observed by CRaTER and Implications for Future Human Deep-Space Exploration

    Science.gov (United States)

    Schwadron, N. A.; Rahmanifard, F.; Wilson, J.; Jordan, A. P.; Spence, H. E.; Joyce, C. J.; Blake, J. B.; Case, A. W.; de Wet, W.; Farrell, W. M.; Kasper, J. C.; Looper, M. D.; Lugaz, N.; Mays, L.; Mazur, J. E.; Niehof, J.; Petro, N.; Smith, C. W.; Townsend, L. W.; Winslow, R.; Zeitlin, C.

    2018-03-01

    Over the last decade, the solar wind has exhibited low densities and magnetic field strengths, representing anomalous states that have never been observed during the space age. As discussed by Schwadron, Blake, et al. (2014, https://doi.org/10.1002/2014SW001084), the cycle 23-24 solar activity led to the longest solar minimum in more than 80 years and continued into the "mini" solar maximum of cycle 24. During this weak activity, we observed galactic cosmic ray fluxes that exceeded theERobserved small solar energetic particle events. Here we provide an update to the Schwadron, Blake, et al. (2014, https://doi.org/10.1002/2014SW001084) observations from the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) on the Lunar Reconnaissance Orbiter. The Schwadron, Blake, et al. (2014, https://doi.org/10.1002/2014SW001084) study examined the evolution of the interplanetary magnetic field and utilized a previously published study by Goelzer et al. (2013, https://doi.org/10.1002/2013JA019404) projecting out the interplanetary magnetic field strength based on the evolution of sunspots as a proxy for the rate that the Sun releases coronal mass ejections. This led to a projection of dose rates from galactic cosmic rays on the lunar surface, which suggested a ˜20% increase of dose rates from one solar minimum to the next and indicated that the radiation environment in space may be a worsening factor important for consideration in future planning of human space exploration. We compare the predictions of Schwadron, Blake, et al. (2014, https://doi.org/10.1002/2014SW001084) with the actual dose rates observed by CRaTER in the last 4 years. The observed dose rates exceed the predictions by ˜10%, showing that the radiation environment is worsening more rapidly than previously estimated. Much of this increase is attributable to relatively low-energy ions, which can be effectively shielded. Despite the continued paucity of solar activity, one of the hardest solar events in

  12. Striction-based Power Monitoring in Space Environment, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The program delivers a completely new technology solution to isolation and sensing of power flow (current and voltage). Based on striction materials technology,...

  13. Design of a space-based infrared imaging interferometer

    Science.gov (United States)

    Hart, Michael; Hope, Douglas; Romeo, Robert

    2017-07-01

    Present space-based optical imaging sensors are expensive. Launch costs are dictated by weight and size, and system design must take into account the low fault tolerance of a system that cannot be readily accessed once deployed. We describe the design and first prototype of the space-based infrared imaging interferometer (SIRII) that aims to mitigate several aspects of the cost challenge. SIRII is a six-element Fizeau interferometer intended to operate in the short-wave and midwave IR spectral regions over a 6×6 mrad field of view. The volume is smaller by a factor of three than a filled-aperture telescope with equivalent resolving power. The structure and primary optics are fabricated from light-weight space-qualified carbon fiber reinforced polymer; they are easy to replicate and inexpensive. The design is intended to permit one-time alignment during assembly, with no need for further adjustment once on orbit. A three-element prototype of the SIRII imager has been constructed with a unit telescope primary mirror diameter of 165 mm and edge-to-edge baseline of 540 mm. The optics, structure, and interferometric signal processing principles draw on experience developed in ground-based astronomical applications designed to yield the highest sensitivity and resolution with cost-effective optical solutions. The initial motivation for the development of SIRII was the long-term collection of technical intelligence from geosynchronous orbit, but the scalable nature of the design will likely make it suitable for a range of IR imaging scenarios.

  14. Virtual Space Exploration: Let's Use Web-Based Computer Game Technology to Boost IYA 2009 Public Interest

    Science.gov (United States)

    Hussey, K.; Doronila, P.; Kulikov, A.; Lane, K.; Upchurch, P.; Howard, J.; Harvey, S.; Woodmansee, L.

    2008-09-01

    With the recent releases of both Google's "Sky" and Microsoft's "WorldWide Telescope" and the large and increasing popularity of video games, the time is now for using these tools, and those crafted at NASA's Jet Propulsion Laboratory, to engage the public in astronomy like never before. This presentation will use "Cassini at Saturn Interactive Explorer " (CASSIE) to demonstrate the power of web-based video-game engine technology in providing the public a "first-person" look at space exploration. The concept of virtual space exploration is to allow the public to "see" objects in space as if they were either riding aboard or "flying" next to an ESA/NASA spacecraft. Using this technology, people are able to immediately "look" in any direction from their virtual location in space and "zoom-in" at will. Users can position themselves near Saturn's moons and observe the Cassini Spacecraft's "encounters" as they happened. Whenever real data for their "view" exists it is incorporated into the scene. Where data is missing, a high-fidelity simulation of the view is generated to fill in the scene. The observer can also change the time of observation into the past or future. Our approach is to utilize and extend the Unity 3d game development tool, currently in use by the computer gaming industry, along with JPL mission specific telemetry and instrument data to build our virtual explorer. The potential of the application of game technology for the development of educational curricula and public engagement are huge. We believe this technology can revolutionize the way the general public and the planetary science community views ESA/NASA missions and provides an educational context that is attractive to the younger generation. This technology is currently under development and application at JPL to assist our missions in viewing their data, communicating with the public and visualizing future mission plans. Real-time demonstrations of CASSIE and other applications in development

  15. The Bus Station Spacing Optimization Based on Game Theory

    Directory of Open Access Journals (Sweden)

    Changjiang Zheng

    2015-01-01

    Full Text Available With the development of city, the problem of traffic is becoming more and more serious. Developing public transportation has become the key to solving this problem in all countries. Based on the existing public transit network, how to improve the bus operation efficiency, and reduce the residents transit trip cost has become a simple and effective way to develop the public transportation. Bus stop spacing is an important factor affecting passengers’ travel time. How to set up bus stop spacing has become the key to reducing passengers’ travel time. According to comprehensive traffic survey, theoretical analysis, and summary of urban public transport characteristics, this paper analyzes the impact of bus stop spacing on passenger in-bus time cost and out-bus time cost and establishes in-bus time and out-bus time model. Finally, the paper gets the balance best station spacing by introducing the game theory.

  16. A global space-based stratospheric aerosol climatology: 1979–2016

    Directory of Open Access Journals (Sweden)

    L. W. Thomason

    2018-03-01

    Full Text Available We describe the construction of a continuous 38-year record of stratospheric aerosol optical properties. The Global Space-based Stratospheric Aerosol Climatology, or GloSSAC, provided the input data to the construction of the Climate Model Intercomparison Project stratospheric aerosol forcing data set (1979–2014 and we have extended it through 2016 following an identical process. GloSSAC focuses on the Stratospheric Aerosol and Gas Experiment (SAGE series of instruments through mid-2005, and on the Optical Spectrograph and InfraRed Imager System (OSIRIS and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO data thereafter. We also use data from other space instruments and from ground-based, air, and balloon borne instruments to fill in key gaps in the data set. The end result is a global and gap-free data set focused on aerosol extinction coefficient at 525 and 1020 nm and other parameters on an "as available" basis. For the primary data sets, we developed a new method for filling the post-Pinatubo eruption data gap for 1991–1993 based on data from the Cryogenic Limb Array Etalon Spectrometer. In addition, we developed a new method for populating wintertime high latitudes during the SAGE period employing a latitude-equivalent latitude conversion process that greatly improves the depiction of aerosol at high latitudes compared to earlier similar efforts. We report data in the troposphere only when and where it is available. This is primarily during the SAGE II period except for the most enhanced part of the Pinatubo period. It is likely that the upper troposphere during Pinatubo was greatly enhanced over non-volcanic periods and that domain remains substantially under-characterized. We note that aerosol levels during the OSIRIS/CALIPSO period in the lower stratosphere at mid- and high latitudes is routinely higher than what we observed during the SAGE II period. While this period had nearly continuous low

  17. Learning of state-space models with highly informative observations: A tempered sequential Monte Carlo solution

    Science.gov (United States)

    Svensson, Andreas; Schön, Thomas B.; Lindsten, Fredrik

    2018-05-01

    Probabilistic (or Bayesian) modeling and learning offers interesting possibilities for systematic representation of uncertainty using probability theory. However, probabilistic learning often leads to computationally challenging problems. Some problems of this type that were previously intractable can now be solved on standard personal computers thanks to recent advances in Monte Carlo methods. In particular, for learning of unknown parameters in nonlinear state-space models, methods based on the particle filter (a Monte Carlo method) have proven very useful. A notoriously challenging problem, however, still occurs when the observations in the state-space model are highly informative, i.e. when there is very little or no measurement noise present, relative to the amount of process noise. The particle filter will then struggle in estimating one of the basic components for probabilistic learning, namely the likelihood p (data | parameters). To this end we suggest an algorithm which initially assumes that there is substantial amount of artificial measurement noise present. The variance of this noise is sequentially decreased in an adaptive fashion such that we, in the end, recover the original problem or possibly a very close approximation of it. The main component in our algorithm is a sequential Monte Carlo (SMC) sampler, which gives our proposed method a clear resemblance to the SMC2 method. Another natural link is also made to the ideas underlying the approximate Bayesian computation (ABC). We illustrate it with numerical examples, and in particular show promising results for a challenging Wiener-Hammerstein benchmark problem.

  18. International Space Station-Based Electromagnetic Launcher for Space Science Payloads

    Science.gov (United States)

    Jones, Ross M.

    2013-01-01

    A method was developed of lowering the cost of planetary exploration missions by using an electromagnetic propulsion/launcher, rather than a chemical-fueled rocket for propulsion. An electromagnetic launcher (EML) based at the International Space Station (ISS) would be used to launch small science payloads to the Moon and near Earth asteroids (NEAs) for the science and exploration missions. An ISS-based electromagnetic launcher could also inject science payloads into orbits around the Earth and perhaps to Mars. The EML would replace rocket technology for certain missions. The EML is a high-energy system that uses electricity rather than propellant to accelerate payloads to high velocities. The most common type of EML is the rail gun. Other types are possible, e.g., a coil gun, also known as a Gauss gun or mass driver. The EML could also "drop" science payloads into the Earth's upper

  19. Robust Predictive Functional Control for Flight Vehicles Based on Nonlinear Disturbance Observer

    Directory of Open Access Journals (Sweden)

    Yinhui Zhang

    2015-01-01

    Full Text Available A novel robust predictive functional control based on nonlinear disturbance observer is investigated in order to address the control system design for flight vehicles with significant uncertainties, external disturbances, and measurement noise. Firstly, the nonlinear longitudinal dynamics of the flight vehicle are transformed into linear-like state-space equations with state-dependent coefficient matrices. And then the lumped disturbances are considered in the linear structure predictive model of the predictive functional control to increase the precision of the predictive output and resolve the intractable mismatched disturbance problem. As the lumped disturbances cannot be derived or measured directly, the nonlinear disturbance observer is applied to estimate the lumped disturbances, which are then introduced to the predictive functional control to replace the unknown actual lumped disturbances. Consequently, the robust predictive functional control for the flight vehicle is proposed. Compared with the existing designs, the effectiveness and robustness of the proposed flight control are illustrated and validated in various simulation conditions.

  20. Programmable wide field spectrograph for earth observation

    Science.gov (United States)

    Zamkotsian, Frédéric; Lanzoni, Patrick; Liotard, Arnaud; Viard, Thierry; Costes, Vincent; Hébert, Philippe-Jean

    2017-11-01

    In Earth Observation, Universe Observation and Planet Exploration, scientific return of the instruments must be optimized in future missions. Micro-Opto-Electro-Mechanical Systems (MOEMS) could be key components in future generation of space instruments. These devices are based on the mature micro-electronics technology and in addition to their compactness, scalability, and specific task customization, they could generate new functions not available with current technologies. French and European space agencies, the Centre National d'Etudes Spatiales (CNES) and the European Space Agency (ESA) have initiated several studies with LAM and TAS for listing the new functions associated with several types of MEMS, and developing new ideas of instruments.

  1. Rule-Based Analytic Asset Management for Space Exploration Systems (RAMSES), Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Payload Systems Inc. (PSI) and the Massachusetts Institute of Technology (MIT) were selected to jointly develop the Rule-based Analytic Asset Management for Space...

  2. A Space-Based Learning Service for Schools Worldwide

    Science.gov (United States)

    White, Norman A.; Gibson, Alan

    2002-01-01

    This paper outlines a scheme for international collaboration to enrich the use of space in school education, to improve students' learning about science and related subjects and to enhance the continuity of science-related studies after the age of 16. Guidelines are presented for the design of an on-line learning service to provide schools worldwide with:- interactive curriculum-related learning resources for teaching about space and through - access to a purpose-designed education satellite or satellites; - opportunities for hands-on work by students in out-of-school hours; - news about space developments to attract, widen and deepen initial interest among teachers - support services to enable teachers to make effective use of the learning service. The Learning Service is the product of almost twenty years of experience by a significant number of UK schools in experimenting with, and in using, satellites and space to aid learning; and over four years of study and development by the SpaceLink Learning Foundation - a private-sector, not- for-profit UK registered charity, which is dedicated to help in increasing both the supply of scientists and engineers and the public understanding of science. This initiative provides scope for, and could benefit from, the involvement of relevant/interested organisations drawn from different countries. The Foundation would be ready, from its UK base, to be among such a group of initiating organisations.

  3. Kaluza-Klein-Carmeli Metric from Quaternion-Clifford Space, Lorentz' Force, and Some Observables

    Directory of Open Access Journals (Sweden)

    Christianto V.

    2008-04-01

    Full Text Available It was known for quite long time that a quaternion space can be generalized to a Clifford space, and vice versa; but how to find its neat link with more convenient metric form in the General Relativity theory, has not been explored extensively. We begin with a representation of group with non-zero quaternions to derive closed FLRW metric [1], and from there obtains Carmeli metric, which can be extended further to become 5D and 6D metric (which we propose to call Kaluza-Klein-Carmeli metric. Thereafter we discuss some plausible implications of this metric, beyond describing a galaxy’s spiraling motion and redshift data as these have been done by Carmeli and Hartnett [4, 5, 6]. In subsequent section we explain Podkletnov’s rotating disc experiment. We also note possible implications to quantum gravity. Further observations are of course recommended in order to refute or verify this proposition.

  4. Riemann Geometric Color-Weak Compensationfor Individual Observers

    OpenAIRE

    Kojima, Takanori; Mochizuki, Rika; Lenz, Reiner; Chao, Jinhui

    2014-01-01

    We extend a method for color weak compensation based on the criterion of preservation of subjective color differences between color normal and color weak observers presented in [2]. We introduce a new algorithm for color weak compensation using local affine maps between color spaces of color normal and color weak observers. We show howto estimate the local affine map and how to determine correspondences between the origins of local coordinates in color spaces of color normal and color weak ob...

  5. Observations and Analyses of Heliospheric Faraday Rotation of a Coronal Mass Ejection (CME) Using the LOw Frequency ARray (LOFAR) and Space-Based Imaging Techniques

    Science.gov (United States)

    Bisi, Mario Mark; Jensen, Elizabeth; Sobey, Charlotte; Fallows, Richard; Jackson, Bernard; Barnes, David; Giunta, Alessandra; Hick, Paul; Eftekhari, Tarraneh; Yu, Hsiu-Shan; Odstrcil, Dusan; Tokumaru, Munetoshi; Wood, Brian

    2017-04-01

    Geomagnetic storms of the highest intensity are general driven by coronal mass ejections (CMEs) impacting the Earth's space environment. Their intensity is driven by the speed, density, and, most-importantly, their magnetic-field orientation and magnitude of the incoming solar plasma. The most-significant magnetic-field factor is the North-South component (Bz in Geocentric Solar Magnetic - GSM - coordinates). At present, there are no reliable prediction methods available for this magnetic-field component ahead of the in-situ monitors around the Sun-Earth L1 point. Observations of Faraday rotation (FR) can be used to attempt to determine average magnetic-field orientations in the inner heliosphere. Such a technique has already been well demonstrated through the corona, ionosphere, and also the interstellar medium. Measurements of the polarisation of astronomical (or spacecraft in superior conjunction) radio sources (beacons/radio frequency carriers) through the inner corona of the Sun to obtain the FR have been demonstrated but mostly at relatively-high radio frequencies. Here we show some initial results of true heliospheric FR using the Low Frequency Array (LOFAR) below 200 MHz to investigate the passage of a coronal mass ejection (CME) across the line of sight. LOFAR is a next-generation low-frequency radio interferometer, and a pathfinder to the Square Kilometre Array (SKA) - LOW telescope. We demonstrate preliminary heliospheric FR results through the analysis of observations of pulsar J1022+1001, which commenced on 13 August 2014 at 13:00UT and spanned over 150 minutes in duration. We also show initial comparisons to the FR results via various modelling techniques and additional context information to understand the structure of the inner heliosphere being detected. This observation could indeed pave the way to an experiment which might be implemented for space-weather purposes that will eventually lead to a near-global method for determining the magnetic

  6. Traversable braneworld wormholes supported by astrophysical observations

    Science.gov (United States)

    Wang, Deng; Meng, Xin-He

    2018-02-01

    In this study, we investigate the characteristics and properties of a traversable wormhole constrained by the current astrophysical observations in the framework of modified theories of gravity (MOG). As a concrete case, we study traversable wormhole space-time configurations in the Dvali-Gabadadze-Porrati (DGP) braneworld scenario, which are supported by the effects of the gravity leakage of extra dimensions. We find that the wormhole space-time structure will open in terms of the 2 σ confidence level when we utilize the joint constraints supernovae (SNe) Ia + observational Hubble parameter data (OHD) + Planck + gravitational wave (GW) and z based on various energy conditions; (ii) we can offer a strict restriction to the local wormhole space-time structure by using the current astrophysical observations; and (iii) we can clearly identify a physical gravitational resource for the wormholes supported by astrophysical observations, namely the dark energy components of the universe or equivalent space-time curvature effects from MOG. Moreover, we find that the strong energy condition is always violated at low redshifts.

  7. Flexible Graphene-Based Energy Storage Devices for Space Application

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this project is to develop a graphene-based battery/ultra-capacitor prototype that is flexible, thin, lightweight, durable, low cost, and safe and...

  8. Free-space communication based on quantum cascade laser

    International Nuclear Information System (INIS)

    Liu Chuanwei; Zhai Shenqiang; Zhang Jinchuan; Zhou Yuhong; Jia Zhiwei; Liu Fengqi; Wang Zhanguo

    2015-01-01

    A free-space communication based on a mid-infrared quantum cascade laser (QCL) is presented. A room-temperature continuous-wave distributed-feedback (DFB) QCL combined with a mid-infrared detector comprise the basic unit of the communication system. Sinusoidal signals at a highest frequency of 40 MHz and modulated video signals with a carrier frequency of 30 MHz were successfully transmitted with this experimental setup. Our research has provided a proof-of-concept demonstration of space optical communication application with QCL. The highest operation frequency of our setup was determined by the circuit-limited modulation bandwidth. A high performance communication system can be obtained with improved modulation circuit system. (paper)

  9. Perovskite-based Photovoltaics: A New Pathway to Ultra- Low-Cost Space Power

    Data.gov (United States)

    National Aeronautics and Space Administration — We will determine if the lifetime performance of new perovskite-based solar cells can be engineered for long-term performance for space applications. We will utilize...

  10. Tests of gravity with future space-based experiments

    Science.gov (United States)

    Sakstein, Jeremy

    2018-03-01

    Future space-based tests of relativistic gravitation—laser ranging to Phobos, accelerometers in orbit, and optical networks surrounding Earth—will constrain the theory of gravity with unprecedented precision by testing the inverse-square law, the strong and weak equivalence principles, and the deflection and time delay of light by massive bodies. In this paper, we estimate the bounds that could be obtained on alternative gravity theories that use screening mechanisms to suppress deviations from general relativity in the Solar System: chameleon, symmetron, and Galileon models. We find that space-based tests of the parametrized post-Newtonian parameter γ will constrain chameleon and symmetron theories to new levels, and that tests of the inverse-square law using laser ranging to Phobos will provide the most stringent constraints on Galileon theories to date. We end by discussing the potential for constraining these theories using upcoming tests of the weak equivalence principle, and conclude that further theoretical modeling is required in order to fully utilize the data.

  11. Earth observations during Space Shuttle Mission STS-42 - Discovery's mission to planet earth

    Science.gov (United States)

    Lulla, Kamlesh P.; Helfert, Michael; Amsbury, David; Pitts, David; Jaklitch, Pat; Wilkinson, Justin; Evans, Cynthia; Ackleson, Steve; Helms, David; Chambers, Mark

    1993-01-01

    The noteworthy imagery acquired during Space Shuttle Mission STS-42 is documented. Attention is given to frozen Tibetan lakes, Merapi Volcano in Java, Mt. Pinatubo in the Philippines, the coastline east of Tokyo Japan, land use in southern India, and the Indus River Delta. Observations of Kamchatka Peninsula, Lake Baikal, Moscow, Katmai National Park and Mt. Augustine, Alaska, the Alaskan coast by the Bering Sea, snow-covered New York, the Rhone River valley, the Strait of Gibraltar, and Mt. Ararat, Turkey, are also reported.

  12. A New Approach to Space Situational Awareness using Small Ground-Based Telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Anheier, Norman C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chen, Cliff S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-12-01

    This report discusses a new SSA approach evaluated by Pacific Northwest National Laboratory (PNNL) that may lead to highly scalable, small telescope observing stations designed to help manage the growing space surveillance burden. Using the methods and observing tools described in this report, the team was able to acquire and track very faint satellites (near Pluto’s apparent brightness). Photometric data was collected and used to correlate object orbital position as a function of atomic clock-derived time. Object apparent brightness was estimated by image analysis and nearby star calibration. The measurement performance was only limited by weather conditions, object brightness, and the sky glow at the observation site. In the future, these new SSA technologies and techniques may be utilized to protect satellite assets, detect and monitor orbiting debris fields, and support Outer Space Treaty monitoring and transparency.

  13. METHOD OF GROUP OBJECTS FORMING FOR SPACE-BASED REMOTE SENSING OF THE EARTH

    Directory of Open Access Journals (Sweden)

    A. N. Grigoriev

    2015-07-01

    Full Text Available Subject of Research. Research findings of the specific application of space-based optical-electronic and radar means for the Earth remote sensing are considered. The subject matter of the study is the current planning of objects survey on the underlying surface in order to increase the effectiveness of sensing system due to the rational use of its resources. Method. New concept of a group object, stochastic swath and stochastic length of the route is introduced. The overview of models for single, group objects and their parameters is given. The criterion for the existence of the group object based on two single objects is formulated. The method for group objects formation while current survey planning has been developed and its description is presented. The method comprises several processing stages for data about objects with the calculation of new parameters, the stochastic characteristics of space means and validates the spatial size of the object value of the stochastic swath and stochastic length of the route. The strict mathematical description of techniques for model creation of a group object based on data about a single object and onboard special complex facilities in difficult conditions of registration of spatial data is given. Main Results. The developed method is implemented on the basis of modern geographic information system in the form of a software tool layout with advanced tools of processing and analysis of spatial data in vector format. Experimental studies of the forming method for the group of objects were carried out on a different real object environment using the parameters of modern national systems of the Earth remote sensing detailed observation Canopus-B and Resurs-P. Practical Relevance. The proposed models and method are focused on practical implementation using vector spatial data models and modern geoinformation technologies. Practical value lies in the reduction in the amount of consumable resources by means of

  14. Observability and Estimation of Distributed Space Systems via Local Information-Exchange Networks

    Science.gov (United States)

    Fathpour, Nanaz; Hadaegh, Fred Y.; Mesbahi, Mehran; Rahmani, Amirreza

    2011-01-01

    Spacecraft formation flying involves the coordination of states among multiple spacecraft through relative sensing, inter-spacecraft communication, and control. Most existing formation-flying estimation algorithms can only be supported via highly centralized, all-to-all, static relative sensing. New algorithms are proposed that are scalable, modular, and robust to variations in the topology and link characteristics of the formation exchange network. These distributed algorithms rely on a local information exchange network, relaxing the assumptions on existing algorithms. Distributed space systems rely on a signal transmission network among multiple spacecraft for their operation. Control and coordination among multiple spacecraft in a formation is facilitated via a network of relative sensing and interspacecraft communications. Guidance, navigation, and control rely on the sensing network. This network becomes more complex the more spacecraft are added, or as mission requirements become more complex. The observability of a formation state was observed by a set of local observations from a particular node in the formation. Formation observability can be parameterized in terms of the matrices appearing in the formation dynamics and observation matrices. An agreement protocol was used as a mechanism for observing formation states from local measurements. An agreement protocol is essentially an unforced dynamic system whose trajectory is governed by the interconnection geometry and initial condition of each node, with a goal of reaching a common value of interest. The observability of the interconnected system depends on the geometry of the network, as well as the position of the observer relative to the topology. For the first time, critical GN&C (guidance, navigation, and control estimation) subsystems are synthesized by bringing the contribution of the spacecraft information-exchange network to the forefront of algorithmic analysis and design. The result is a

  15. Momentum-space resummation for transverse observables and the Higgs p ⊥ at N3LL+NNLO

    Science.gov (United States)

    Bizoń, Wojciech; Monni, Pier Francesco; Re, Emanuele; Rottoli, Luca; Torrielli, Paolo

    2018-02-01

    We present an approach to the momentum-space resummation of global, recursively infrared and collinear safe observables that can vanish away from the Sudakov region. We focus on the hadro-production of a generic colour singlet, and we consider the class of observables that depend only upon the total transverse momentum of the radiation, prime examples being the transverse momentum of the singlet, and ϕ ∗ in Drell-Yan pair production. We derive a resummation formula valid up to next-to-next-to-next-to-leading-logarithmic accuracy for the considered class of observables. We use this result to compute state-of-the-art predictions for the Higgs-boson transverse-momentum spectrum at the LHC at next-to-next-to-next-to-leading-logarithmic accuracy matched to fixed next-to-next-to-leading order. Our resummation formula reduces exactly to the customary resummation performed in impact-parameter space in the known cases, and it also predicts the correct power-behaved scaling of the cross section in the limit of small value of the observable. We show how this formalism is efficiently implemented by means of Monte Carlo techniques in a fully exclusive generator that allows one to apply arbitrary cuts on the Born variables for any colour singlet, as well as to automatically match the resummed results to fixed-order calculations.

  16. Real-space observation of nanojet-induced modes in a chain of microspheres

    International Nuclear Information System (INIS)

    Liu, Cheng-Yang; Wang, Po-Kai

    2014-01-01

    The three-dimensional real-space observation of photonic nanojet-induced modes in a chain of microspheres with different diameters is reported. The optical transmission properties of a chain of microspheres are studied by using high resolution finite-difference time-domain calculation. The photonic nanojet-induced modes in different chains of microspheres are measured by using a scanning optical microscope system with an optical-fiber probe. We observe the photonic nanojet-induced modes from optical microscope images for chains of 3 μm, 5 μm, and 8 μm microspheres deposited on a patterned silicon substrate. The incident beam can be periodically reproduced in chains of dielectric microspheres giving rise to lossless periodically optical focusing with period of two diameters. Detailed theoretical and experimental data on the transmission, scattering loss, and field-of-view are presented. This waveguide technique can be used in biomedical microscopy, ultra-precise laser process, microfluidics, and nanophotonic circuits.

  17. Real-space observation of nanojet-induced modes in a chain of microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Cheng-Yang, E-mail: cyliu@mail.tku.edu.tw; Wang, Po-Kai

    2014-04-01

    The three-dimensional real-space observation of photonic nanojet-induced modes in a chain of microspheres with different diameters is reported. The optical transmission properties of a chain of microspheres are studied by using high resolution finite-difference time-domain calculation. The photonic nanojet-induced modes in different chains of microspheres are measured by using a scanning optical microscope system with an optical-fiber probe. We observe the photonic nanojet-induced modes from optical microscope images for chains of 3 μm, 5 μm, and 8 μm microspheres deposited on a patterned silicon substrate. The incident beam can be periodically reproduced in chains of dielectric microspheres giving rise to lossless periodically optical focusing with period of two diameters. Detailed theoretical and experimental data on the transmission, scattering loss, and field-of-view are presented. This waveguide technique can be used in biomedical microscopy, ultra-precise laser process, microfluidics, and nanophotonic circuits.

  18. Image Analysis Based on Soft Computing and Applied on Space Shuttle During the Liftoff Process

    Science.gov (United States)

    Dominquez, Jesus A.; Klinko, Steve J.

    2007-01-01

    Imaging techniques based on Soft Computing (SC) and developed at Kennedy Space Center (KSC) have been implemented on a variety of prototype applications related to the safety operation of the Space Shuttle during the liftoff process. These SC-based prototype applications include detection and tracking of moving Foreign Objects Debris (FOD) during the Space Shuttle liftoff, visual anomaly detection on slidewires used in the emergency egress system for the Space Shuttle at the laJlIlch pad, and visual detection of distant birds approaching the Space Shuttle launch pad. This SC-based image analysis capability developed at KSC was also used to analyze images acquired during the accident of the Space Shuttle Columbia and estimate the trajectory and velocity of the foam that caused the accident.

  19. Command and Control of Space Assets Through Internet-Based Technologies Demonstrated

    Science.gov (United States)

    Foltz, David A.

    2002-01-01

    The NASA Glenn Research Center successfully demonstrated a transmission-control-protocol/ Internet-protocol- (TCP/IP) based approach to the command and control of onorbit assets over a secure network. This is a significant accomplishment because future NASA missions will benefit by using Internet-standards-based protocols. Benefits of this Internet-based space command and control system architecture include reduced mission costs and increased mission efficiency. The demonstration proved that this communications architecture is viable for future NASA missions. This demonstration was a significant feat involving multiple NASA organizations and industry. Phillip Paulsen, from Glenn's Project Development and Integration Office, served as the overall project lead, and David Foltz, from Glenn's Satellite Networks and Architectures Branch, provided the hybrid networking support for the required Internet connections. The goal was to build a network that would emulate a connection between a space experiment on the International Space Station and a researcher accessing the experiment from anywhere on the Internet, as shown. The experiment was interfaced to a wireless 802.11 network inside the demonstration area. The wireless link provided connectivity to the Tracking and Data Relay Satellite System (TDRSS) Internet Link Terminal (TILT) satellite uplink terminal located 300 ft away in a parking lot on top of a panel van. TILT provided a crucial link in this demonstration. Leslie Ambrose, NASA Goddard Space Flight Center, provided the TILT/TDRSS support. The TILT unit transmitted the signal to TDRS 6 and was received at the White Sands Second TDRSS Ground Station. This station provided the gateway to the Internet. Coordination also took place at the White Sands station to install a Veridian Firewall and automated security incident measurement (ASIM) system to the Second TDRSS Ground Station Internet gateway. The firewall provides a trusted network for the simulated space

  20. Johnson Space Center's Solar and Wind-Based Renewable Energy System

    Science.gov (United States)

    Vasquez, A.; Ewert, M.; Rowlands, J.; Post, K.

    2009-01-01

    The NASA Johnson Space Center (JSC) in Houston, Texas has a Sustainability Partnership team that seeks ways for earth-based sustainability practices to also benefit space exploration research. A renewable energy gathering system was installed in 2007 at the JSC Child Care Center (CCC) which also offers a potential test bed for space exploration power generation and remote monitoring and control concepts. The system comprises: 1) several different types of photovoltaic panels (29 kW), 2) two wind-turbines (3.6 kW total), and 3) one roof-mounted solar thermal water heater and tank. A tie to the JSC local electrical grid was provided to accommodate excess power. The total first year electrical energy production was 53 megawatt-hours. A web-based real-time metering system collects and reports system performance and weather data. Improvements in areas of the CCC that were detected during subsequent energy analyses and some concepts for future efforts are also presented.

  1. Object-based warping: an illusory distortion of space within objects.

    Science.gov (United States)

    Vickery, Timothy J; Chun, Marvin M

    2010-12-01

    Visual objects are high-level primitives that are fundamental to numerous perceptual functions, such as guidance of attention. We report that objects warp visual perception of space in such a way that spatial distances within objects appear to be larger than spatial distances in ground regions. When two dots were placed inside a rectangular object, they appeared farther apart from one another than two dots with identical spacing outside of the object. To investigate whether this effect was object based, we measured the distortion while manipulating the structure surrounding the dots. Object displays were constructed with a single object, multiple objects, a partially occluded object, and an illusory object. Nonobject displays were constructed to be comparable to object displays in low-level visual attributes. In all cases, the object displays resulted in a more powerful distortion of spatial perception than comparable non-object-based displays. These results suggest that perception of space within objects is warped.

  2. The Library as a Preferred Place for Studying: Observation of Students’ Use of Physical Spaces. A Review of: Applegate, R. (2009. The library is for studying: Student preferences for study space. The Journal of Academic Librarianship, 35(4, 341-346.

    Directory of Open Access Journals (Sweden)

    Annie M. Hughes

    2011-06-01

    Full Text Available Objective – To determine students’ utilization of physical spaces in the library, excluding computer labs or stacks.Design – Observational research, unobtrusive method.Setting – Areas of space in the University Library, as well as within adjoining areas at Indiana University-Purdue University Indianapolis, such as carrels, tables, soft chairs, and study rooms.Subjects – Students using the library’s space.Methods – The researcher chose to collect data via observation of individuals and groups in a particular space in the library, noting the gender of the individuals using the space and whether or not they were using laptops. Areas of space examined were carrels, group study rooms, chairs and sofas, tables and chairs in the Academic Commons, and benches and chairs within corridors. The unit of analysis used was equal to an individual seat. The research excluded stack space as well as any space with fixed computer stations. The time periods chosen to study the spaces were selected based on the author’s previous research. Due to higher daytime usage than evening, data was collected at two time periods during the day: 12-1 p.m. and 3-4 p.m., Monday through Friday. The researcher recorded the time of the semester as well, choosing weeks 14-17 in Fall 2007 and weeks 10-17 in Spring 2008. Space diagrams for collecting data were created, and each area had different collection times. All data was entered into a database in which each area was recorded with the number and type of users. Each area had a different capacity as to how many individuals it could hold. If the percentage of capacity was higher than 50%, the usage was considered to be notable.Main Results – The researchers observed a few patterns from their data collection. Gender analysis provided information regarding the use of laptops; men were more likely to use them than women. While men were a smaller part of the overall university demographic while this research took place

  3. Community Based Distribution of Child Spacing Methods at ...

    African Journals Online (AJOL)

    uses volunteer CBD agents. Mrs. E.F. Pelekamoyo. Service Delivery Officer. National Family Welfare Council of Malawi. Private Bag 308. Lilongwe 3. Malawi. Community Based Distribution of. Child Spacing Methods ... than us at the Hospital; male motivators by talking to their male counterparts help them to accept that their ...

  4. Analysis of CPolSK-based FSO system working in space-to-ground channel

    Science.gov (United States)

    Su, Yuwei; Sato, Takuro

    2018-03-01

    In this article, the transmission performance of a circle polarization shift keying (CPolSK)-based free space optical (FSO) system working in space-to-ground channel is analyzed. Formulas describing the optical polarization distortion caused by the atmospheric turbulence and the communication qualities in terms of signal-to-noise-ratio (SNR), bit-error-ratio (BER) and outage probability of the proposed system are derived. Based on the Stokes parameters data measured by a Japanese optical communication satellite, we evaluate the space-to-ground FSO link and simulate the system performance under a varying regime of turbulence strength. The proposed system provides a more efficient way to compensate scintillation effects in a comparison with the on-off-keying (OOK)-based FSO system. These results are useful to the designing and evaluating of a deep space FSO communication system.

  5. New Constraints on ΩM, ΩΛ, and w from an Independent Set of 11 High-Redshift Supernovae Observed with the Hubble Space Telescope

    Science.gov (United States)

    Knop, R. A.; Aldering, G.; Amanullah, R.; Astier, P.; Blanc, G.; Burns, M. S.; Conley, A.; Deustua, S. E.; Doi, M.; Ellis, R.; Fabbro, S.; Folatelli, G.; Fruchter, A. S.; Garavini, G.; Garmond, S.; Garton, K.; Gibbons, R.; Goldhaber, G.; Goobar, A.; Groom, D. E.; Hardin, D.; Hook, I.; Howell, D. A.; Kim, A. G.; Lee, B. C.; Lidman, C.; Mendez, J.; Nobili, S.; Nugent, P. E.; Pain, R.; Panagia, N.; Pennypacker, C. R.; Perlmutter, S.; Quimby, R.; Raux, J.; Regnault, N.; Ruiz-Lapuente, P.; Sainton, G.; Schaefer, B.; Schahmaneche, K.; Smith, E.; Spadafora, A. L.; Stanishev, V.; Sullivan, M.; Walton, N. A.; Wang, L.; Wood-Vasey, W. M.; Yasuda, N.

    2003-11-01

    observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs GO-7336, GO-7590, and GO-8346. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. Based in part on observations obtained at the WIYN Observatory, which is a joint facility of the University of Wisconsin at Madison, Indiana University, Yale University, and the National Optical Astronomy Observatory. Based in part on observations made with the European Southern Observatory telescopes (ESO programs 60.A-0586 and 265.A-5721). Based in part on observations made with the Canada-France-Hawaii Telescope, operated by the National Research Council of Canada, le Centre National de la Recherche Scientifique de France, and the University of Hawaii.

  6. 3 x 3 free-space optical router based on crossbar network and its control algorithm

    Science.gov (United States)

    Hou, Peipei; Sun, Jianfeng; Yu, Zhou; Lu, Wei; Wang, Lijuan; Liu, Liren

    2015-08-01

    A 3 × 3 free-space optical router, which comprises optical switches and polarizing beam splitter (PBS) and based on crossbar network, is proposed in this paper. A control algorithm for the 3 × 3 free-space optical router is also developed to achieve rapid control without rearrangement. In order to test the performance of the network based on 3 × 3 free-space optical router and that of the algorithm developed for the optical router, experiments are designed. The experiment results show that the interconnection network based on the 3 × 3 free-space optical router has low cross talk, fast connection speed. Under the control of the algorithm developed, a non-block and real free interconnection network is obtained based on the 3 × 3 free-space optical router we proposed.

  7. NASA GSFC Space Weather Center - Innovative Space Weather Dissemination: Web-Interfaces, Mobile Applications, and More

    Science.gov (United States)

    Maddox, Marlo; Zheng, Yihua; Rastaetter, Lutz; Taktakishvili, A.; Mays, M. L.; Kuznetsova, M.; Lee, Hyesook; Chulaki, Anna; Hesse, Michael; Mullinix, Richard; hide

    2012-01-01

    The NASA GSFC Space Weather Center (http://swc.gsfc.nasa.gov) is committed to providing forecasts, alerts, research, and educational support to address NASA's space weather needs - in addition to the needs of the general space weather community. We provide a host of services including spacecraft anomaly resolution, historical impact analysis, real-time monitoring and forecasting, custom space weather alerts and products, weekly summaries and reports, and most recently - video casts. There are many challenges in providing accurate descriptions of past, present, and expected space weather events - and the Space Weather Center at NASA GSFC employs several innovative solutions to provide access to a comprehensive collection of both observational data, as well as space weather model/simulation data. We'll describe the challenges we've faced with managing hundreds of data streams, running models in real-time, data storage, and data dissemination. We'll also highlight several systems and tools that are utilized by the Space Weather Center in our daily operations, all of which are available to the general community as well. These systems and services include a web-based application called the Integrated Space Weather Analysis System (iSWA http://iswa.gsfc.nasa.gov), two mobile space weather applications for both IOS and Android devices, an external API for web-service style access to data, google earth compatible data products, and a downloadable client-based visualization tool.

  8. Sea-ice monitoring by ship-based visual observation during JARE ―Simplification of observation method based on the ASPeCt protocol―

    OpenAIRE

    Kay I. Ohshima; Shuki Ushio; Akihisa S. Otsuki

    2006-01-01

    A protocol for ship-based visual observation of sea ice is proposed for the Japanese Antarctic Research Expedition (JARE). The protocol is a simplified version of the ASPeCt protocol, used for extracting quantitative information on sea ice. The ship-based visual observations started from JARE-46. In the pack ice region, ice thickness, ratio of deformed ice, and total ice volume increased toward the coast. Continuous monitoring of sea ice, particularly its thickness, by ship-based observation ...

  9. Hybrid task priority-based motion control of a redundant free-floating space robot

    Directory of Open Access Journals (Sweden)

    Cheng ZHOU

    2017-12-01

    Full Text Available This paper presents a novel hybrid task priority-based motion planning algorithm of a space robot. The satellite attitude control task is defined as the primary task, while the least-squares-based non-strict task priority solution of the end-effector plus the multi-constraint task is viewed as the secondary task. Furthermore, a null-space task compensation strategy in the joint space is proposed to derive the combination of non-strict and strict task-priority motion planning, and this novel combination is termed hybrid task priority control. Thus, the secondary task is implemented in the primary task’s null-space. Besides, the transition of the state of multiple constraints between activeness and inactiveness will only influence the end-effector task without any effect on the primary task. A set of numerical experiments made in a real-time simulation system under Linux/RTAI shows the validity and feasibility of the proposed methodology. Keywords: Base attitude control, Hybrid task-priority, Motion planning, Multiple constraints, Redundant space robot

  10. Subtropical and Polar Cirrus Clouds Characterized by Ground-Based Lidars and CALIPSO/CALIOP Observations

    Directory of Open Access Journals (Sweden)

    Córdoba-Jabonero Carmen

    2016-01-01

    Full Text Available Cirrus clouds are product of weather processes, and then their occurrence and macrophysical/optical properties can vary significantly over different regions of the world. Lidars can provide height-resolved measurements with a relatively good both vertical and temporal resolutions, making them the most suitable instrumentation for high-cloud observations. The aim of this work is to show the potential of lidar observations on Cirrus clouds detection in combination with a recently proposed methodology to retrieve the Cirrus clouds macrophysical and optical features. In this sense, a few case studies of cirrus clouds observed at both subtropical and polar latitudes are examined and compared to CALIPSO/CALIOP observations. Lidar measurements are carried out in two stations: the Metropolitan city of Sao Paulo (MSP, Brazil, 23.3°S 46.4°W, located at subtropical latitudes, and the Belgrano II base (BEL, Argentina, 78ºS 35ºW in the Antarctic continent. Optical (COD-cloud optical depth and LR-Lidar Ratio and macrophysical (top/base heights and thickness properties of both the subtropical and polar cirrus clouds are reported. In general, subtropical Cirrus clouds present lower LR values and are found at higher altitudes than those detected at polar latitudes. In general, Cirrus clouds are detected at similar altitudes by CALIOP. However, a poor agreement is achieved in the LR retrieved between ground-based lidars and space-borne CALIOP measurements, likely due to the use of a fixed (or low-variable LR value in CALIOP inversion procedures.

  11. Development of a Multivariable Parametric Cost Analysis for Space-Based Telescopes

    Science.gov (United States)

    Dollinger, Courtnay

    2011-01-01

    Over the past 400 years, the telescope has proven to be a valuable tool in helping humankind understand the Universe around us. The images and data produced by telescopes have revolutionized planetary, solar, stellar, and galactic astronomy and have inspired a wide range of people, from the child who dreams about the images seen on NASA websites to the most highly trained scientist. Like all scientific endeavors, astronomical research must operate within the constraints imposed by budget limitations. Hence the importance of understanding cost: to find the balance between the dreams of scientists and the restrictions of the available budget. By logically analyzing the data we have collected for over thirty different telescopes from more than 200 different sources, statistical methods, such as plotting regressions and residuals, can be used to determine what drives the cost of telescopes to build and use a cost model for space-based telescopes. Previous cost models have focused their attention on ground-based telescopes due to limited data for space telescopes and the larger number and longer history of ground-based astronomy. Due to the increased availability of cost data from recent space-telescope construction, we have been able to produce and begin testing a comprehensive cost model for space telescopes, with guidance from the cost models for ground-based telescopes. By separating the variables that effect cost such as diameter, mass, wavelength, density, data rate, and number of instruments, we advance the goal to better understand the cost drivers of space telescopes.. The use of sophisticated mathematical techniques to improve the accuracy of cost models has the potential to help society make informed decisions about proposed scientific projects. An improved knowledge of cost will allow scientists to get the maximum value returned for the money given and create a harmony between the visions of scientists and the reality of a budget.

  12. Tropospheric methanol observations from space: retrieval evaluation and constraints on the seasonality of biogenic emissions

    Directory of Open Access Journals (Sweden)

    K. C. Wells

    2012-07-01

    Full Text Available Methanol retrievals from nadir-viewing space-based sensors offer powerful new information for quantifying methanol emissions on a global scale. Here we apply an ensemble of aircraft observations over North America to evaluate new methanol measurements from the Tropospheric Emission Spectrometer (TES on the Aura satellite, and combine the TES data with observations from the Infrared Atmospheric Sounding Interferometer (IASI on the MetOp-A satellite to investigate the seasonality of methanol emissions from northern midlatitude ecosystems. Using the GEOS-Chem chemical transport model as an intercomparison platform, we find that the TES retrieval performs well when the degrees of freedom for signal (DOFS are above 0.5, in which case the model:TES regressions are generally consistent with the model:aircraft comparisons. Including retrievals with DOFS below 0.5 degrades the comparisons, as these are excessively influenced by the a priori. The comparisons suggest DOFS >0.5 as a minimum threshold for interpreting retrievals of trace gases with a weak tropospheric signal. We analyze one full year of satellite observations and find that GEOS-Chem, driven with MEGANv2.1 biogenic emissions, underestimates observed methanol concentrations throughout the midlatitudes in springtime, with the timing of the seasonal peak in model emissions 1–2 months too late. We attribute this discrepancy to an underestimate of emissions from new leaves in MEGAN, and apply the satellite data to better quantify the seasonal change in methanol emissions for midlatitude ecosystems. The derived parameters (relative emission factors of 11.0, 0.26, 0.12 and 3.0 for new, growing, mature, and old leaves, respectively, plus a leaf area index activity factor of 0.5 for expanding canopies with leaf area index <1.2 provide a more realistic simulation of seasonal methanol concentrations in midlatitudes on the basis of both the IASI and TES measurements.

  13. New advanced netted ground based and topside radio diagnostics for Space Weather Program

    Science.gov (United States)

    Rothkaehl, Hanna; Krankowski, Andrzej; Morawski, Marek; Atamaniuk, Barbara; Zakharenkova, Irina; Cherniak, Iurii

    2014-05-01

    To give a more detailed and complete understanding of physical plasma processes that govern the solar-terrestrial space, and to develop qualitative and quantitative models of the magnetosphere-ionosphere-thermosphere coupling, it is necessary to design and build the next generation of instruments for space diagnostics and monitoring. Novel ground- based wide-area sensor networks, such as the LOFAR (Low Frequency Array) radar facility, comprising wide band, and vector-sensing radio receivers and multi-spacecraft plasma diagnostics should help solve outstanding problems of space physics and describe long-term environmental changes. The LOw Frequency ARray - LOFAR - is a new fully digital radio telescope designed for frequencies between 30 MHz and 240 MHz located in Europe. The three new LOFAR stations will be installed until summer 2015 in Poland. The LOFAR facilities in Poland will be distributed among three sites: Lazy (East of Krakow), Borowiec near Poznan and Baldy near Olsztyn. All they will be connected via PIONIER dedicated links to Poznan. Each site will host one LOFAR station (96 high-band+96 low-band antennas). They will most time work as a part of European network, however, when less charged, they can operate as a national network The new digital radio frequency analyzer (RFA) on board the low-orbiting RELEC satellite was designed to monitor and investigate the ionospheric plasma properties. This two-point ground-based and topside ionosphere-located space plasma diagnostic can be a useful new tool for monitoring and diagnosing turbulent plasma properties. The RFA on board the RELEC satellite is the first in a series of experiments which is planned to be launched into the near-Earth environment. In order to improve and validate the large scales and small scales ionospheric structures we will used the GPS observations collected at IGS/EPN network employed to reconstruct diurnal variations of TEC using all satellite passes over individual GPS stations and the

  14. Crop Production for Advanced Life Support Systems - Observations From the Kennedy Space Center Breadboard Project

    Science.gov (United States)

    Wheeler, R. M.; Sager, J. C.; Prince, R. P.; Knott, W. M.; Mackowiak, C. L.; Stutte, G. W.; Yorio, N. C.; Ruffe, L. M.; Peterson, B. V.; Goins, G. D.

    2003-01-01

    The use of plants for bioregenerative life support for space missions was first studied by the US Air Force in the 1950s and 1960s. Extensive testing was also conducted from the 1960s through the 1980s by Russian researchers located at the Institute of Biophysics in Krasnoyarsk, Siberia, and the Institute for Biomedical Problems in Moscow. NASA initiated bioregenerative research in the 1960s (e.g., Hydrogenomonas) but this research did not include testing with plants until about 1980, with the start of the Controlled Ecological Life Support System (CELSS) Program. The NASA CELSS research was carried out at universities, private corporations, and NASA field centers, including Kennedy Space Center (KSC). The project at KSC began in 1985 and was called the CELSS Breadboard Project to indicate the capability for plugging in and testing various life support technologies; this name has since been dropped but bioregenerative testing at KSC has continued to the present under the NASA s Advanced Life Support (ALS) Program. A primary objective of the KSC testing was to conduct pre-integration tests with plants (crops) in a large, atmospherically closed test chamber called the Biomass Production Chamber (BPC). Test protocols for the BPC were based on observations and growing procedures developed by university investigators, as well as procedures developed in plant growth chamber studies at KSC. Growth chamber studies to support BPC testing focused on plant responses to different carbon dioxide (CO2) concentrations, different spectral qualities from various electric lamps, and nutrient film hydroponic culture techniques.

  15. The First Simultaneous Microlensing Observations by Two Space Telescopes: Spitzer and Swift Reveal a Brown Dwarf in Event OGLE-2015-BLG-1319

    Science.gov (United States)

    Shvartzvald, Y.; Li, Z.; Udalski, A.; Gould, A.; Sumi, T.; Street, R. A.; Calchi Novati, S.; Hundertmark, M.; Bozza, V.; Beichman, C.; hide

    2016-01-01

    Simultaneous observations of microlensing events from multiple locations allow for the breaking of degeneracies between the physical properties of the lensing system, specifically by exploring different regions of the lens plane and by directly measuring the "microlens parallax". We report the discovery of a 30-65M J brown dwarf orbiting a K dwarf in the microlensing event OGLE-2015-BLG-1319. The system is located at a distance of approximately 5 kpc toward the Galactic Bulge. The event was observed by several ground-based groups as well as by Spitzer and Swift, allowing a measurement of the physical properties. However, the event is still subject to an eight-fold degeneracy, in particular the well-known close-wide degeneracy, and thus the projected separation between the two lens components is either approximately 0.25 au or approximately 45 au. This is the first microlensing event observed by Swift, with the UVOT camera. We study the region of microlensing parameter space to which Swift is sensitive, finding that though Swift could not measure the microlens parallax with respect to ground-based observations for this event, it can be important for other events. Specifically, it is important for detecting nearby brown dwarfs and free-floating planets in high magnification events.

  16. Atmospheric Signatures and Effects of Space-based Relativistic Electron Beam Injection

    Science.gov (United States)

    Marshall, R. A.; Sanchez, E. R.; Kero, A.; Turunen, E. S.; Marsh, D. R.

    2017-12-01

    Future relativistic electron beam injection experiments have the potential to provide groundbreaking insights into the physics of wave-particle interactions and beam-neutral interactions, relevant to space physics and to fundamental plasma physics. However, these experiments are only useful if their signatures can be detected. In this work, we use a physics-based forward modeling framework to investigate the observable signatures of a relativistic beam interacting with the upper atmosphere. The modeling framework is based around the Electron Precipitation Monte Carlo (EPMC) model, used to simulate electron precipitation in the upper atmosphere. That model is coupled to physics-based models of i) optical emission production; ii) bremsstrahlung photon production and propagation; iii) D-region ion chemistry; and iv) VLF wave propagation in the Earth-ionosphere waveguide. Using these modeling tools, we predict the optical, X-ray, chemical, radar, and VLF signatures of a realistic beam injection, based on recent space-based accelerator designs. In particular, we inject a beam pulse of 10 mA for a duration of 500 μs at an energy of 1 MeV, providing a total pulse energy of 5 J. We further investigate variations in these parameters, in particular the total energy and the electron energy. Our modeling shows that for this 5 J pulse injection at 1 MeV electron energy, the optical signal is easily detectable from the ground in common emission bands, but the X-ray signal is likely too weak to be seen from either balloons or LEO orbiting spacecraft. We further predict the optical signal-to-noise ratio that would be expected in different optical systems. Chemical signatures such as changes to NOx and HOx concentrations are too short-lived to be detectable; however our modeling provides a valuable estimate of the total chemical response. Electron density perturbations should be easily measurable from ground-based high-power radars and via VLF subionospheric remote sensing

  17. Comparison of EISCAT and ionosonde electron densities: application to a ground-based ionospheric segment of a space weather programme

    Directory of Open Access Journals (Sweden)

    J. Lilensten

    2005-01-01

    Full Text Available Space weather applications require real-time data and wide area observations from both ground- and space-based instrumentation. From space, the global navigation satellite system - GPS - is an important tool. From the ground the incoherent scatter (IS radar technique permits a direct measurement up to the topside region, while ionosondes give good measurements of the lower part of the ionosphere. An important issue is the intercalibration of these various instruments. In this paper, we address the intercomparison of the EISCAT IS radar and two ionosondes located at Tromsø (Norway, at times when GPS measurements were also available. We show that even EISCAT data calibrated using ionosonde data can lead to different values of total electron content (TEC when compared to that obtained from GPS.

  18. A bootstrap based space-time surveillance model with an application to crime occurrences

    Science.gov (United States)

    Kim, Youngho; O'Kelly, Morton

    2008-06-01

    This study proposes a bootstrap-based space-time surveillance model. Designed to find emerging hotspots in near-real time, the bootstrap based model is characterized by its use of past occurrence information and bootstrap permutations. Many existing space-time surveillance methods, using population at risk data to generate expected values, have resulting hotspots bounded by administrative area units and are of limited use for near-real time applications because of the population data needed. However, this study generates expected values for local hotspots from past occurrences rather than population at risk. Also, bootstrap permutations of previous occurrences are used for significant tests. Consequently, the bootstrap-based model, without the requirement of population at risk data, (1) is free from administrative area restriction, (2) enables more frequent surveillance for continuously updated registry database, and (3) is readily applicable to criminology and epidemiology surveillance. The bootstrap-based model performs better for space-time surveillance than the space-time scan statistic. This is shown by means of simulations and an application to residential crime occurrences in Columbus, OH, year 2000.

  19. Condition Based Maintenance of Space Exploration Vehicles Using Structural Health Monitoring, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Acellent Technologies proposes to develop an autonomous and automated diagnostic system for condition based maintenance (CBM) of safety critical structures for space...

  20. Observations of electron phase-space holes driven during magnetic reconnection in a laboratory plasma

    Science.gov (United States)

    Fox, W.; Porkolab, M.; Egedal, J.; Katz, N.; Le, A.

    2012-03-01

    This work presents detailed experimental observations of electron phase-space holes driven during magnetic reconnection events on the Versatile Toroidal Facility. The holes are observed to travel on the order of or faster than the electron thermal speed, and are of large size scale, with diameter of order 60 Debye lengths. In addition, they have 3D spheroidal structure with approximately unity aspect ratio. We estimate the direct anomalous resistivity due to ion interaction with the holes and find it to be too small to affect the reconnection rate; however, the holes may play a role in reining in a tail of accelerated electrons and they indicate the presence of other processes in the reconnection layer, such as electron energization and electron beam formation.

  1. Computers for Manned Space Applications Base on Commercial Off-the-Shelf Components

    Science.gov (United States)

    Vogel, T.; Gronowski, M.

    2009-05-01

    Similar to the consumer markets there has been an ever increasing demand in processing power, signal processing capabilities and memory space also for computers used for science data processing in space. An important driver of this development have been the payload developers for the International Space Station, requesting high-speed data acquisition and fast control loops in increasingly complex systems. Current experiments now even perform video processing and compression with their payload controllers. Nowadays the requirements for a space qualified computer are often far beyond the capabilities of, for example, the classic SPARC architecture that is found in ERC32 or LEON CPUs. An increase in performance usually demands costly and power consuming application specific solutions. Continuous developments over the last few years have now led to an alternative approach that is based on complete electronics modules manufactured for commercial and industrial customers. Computer modules used in industrial environments with a high demand for reliability under harsh environmental conditions like chemical reactors, electrical power plants or on manufacturing lines are entered into a selection procedure. Promising candidates then undergo a detailed characterisation process developed by Astrium Space Transportation. After thorough analysis and some modifications, these modules can replace fully qualified custom built electronics in specific, although not safety critical applications in manned space. This paper focuses on the benefits of COTS1 based electronics modules and the necessary analyses and modifications for their utilisation in manned space applications on the ISS. Some considerations regarding overall systems architecture will also be included. Furthermore this paper will also pinpoint issues that render such modules unsuitable for specific tasks, and justify the reasons. Finally, the conclusion of this paper will advocate the implementation of COTS based

  2. Fiber-based laser MOPA transmitter packaging for space environment

    Science.gov (United States)

    Stephen, Mark; Yu, Anthony; Chen, Jeffrey; Numata, Kenji; Wu, Stewart; Gonzales, Brayler; Han, Lawrence; Fahey, Molly; Plants, Michael; Rodriguez, Michael; Allan, Graham; Abshire, James; Nicholson, Jeffrey; Hariharan, Anand; Mamakos, William; Bean, Brian

    2018-02-01

    NASA's Goddard Space Flight Center has been developing lidar to remotely measure CO2 and CH4 in the Earth's atmosphere. The ultimate goal is to make space-based satellite measurements with global coverage. We are working on maturing the technology readiness of a fiber-based, 1.57-micron wavelength laser transmitter designed for use in atmospheric CO2 remote-sensing. To this end, we are building a ruggedized prototype to demonstrate the required power and performance and survive the required environment. We are building a fiber-based master oscillator power amplifier (MOPA) laser transmitter architecture. The laser is a wavelength-locked, single frequency, externally modulated DBR operating at 1.57-micron followed by erbium-doped fiber amplifiers. The last amplifier stage is a polarization-maintaining, very-large-mode-area fiber with 1000 μm2 effective area pumped by a Raman fiber laser. The optical output is single-frequency, one microsecond pulses with >450 μJ pulse energy, 7.5 KHz repetition rate, single spatial mode, and < 20 dB polarization extinction.

  3. Using Citizen Science Observations to Model Species Distributions Over Space, Through Time, and Across Scales

    Science.gov (United States)

    Kelling, S.

    2017-12-01

    The goal of Biodiversity research is to identify, explain, and predict why a species' distribution and abundance vary through time, space, and with features of the environment. Measuring these patterns and predicting their responses to change are not exercises in curiosity. Today, they are essential tasks for understanding the profound effects that humans have on earth's natural systems, and for developing science-based environmental policies. To gain insight about species' distribution patterns requires studying natural systems at appropriate scales, yet studies of ecological processes continue to be compromised by inadequate attention to scale issues. How spatial and temporal patterns in nature change with scale often reflects fundamental laws of physics, chemistry, or biology, and we can identify such basic, governing laws only by comparing patterns over a wide range of scales. This presentation will provide several examples that integrate bird observations made by volunteers, with NASA Earth Imagery using Big Data analysis techniques to analyze the temporal patterns of bird occurrence across scales—from hemisphere-wide views of bird distributions to the impact of powerful city lights on bird migration.

  4. Low degree Earth's gravity coefficients determined from different space geodetic observations and climate models

    Science.gov (United States)

    Wińska, Małgorzata; Nastula, Jolanta

    2017-04-01

    Large scale mass redistribution and its transport within the Earth system causes changes in the Earth's rotation in space, gravity field and Earth's ellipsoid shape. These changes are observed in the ΔC21, ΔS21, and ΔC20 spherical harmonics gravity coefficients, which are proportional to the mass load-induced Earth rotational excitations. In this study, linear trend, decadal, inter-annual, and seasonal variations of low degree spherical harmonics coefficients of Earth's gravity field, determined from different space geodetic techniques, Gravity Recovery and Climate Experiment (GRACE), satellite laser ranging (SLR), Global Navigation Satellite System (GNSS), Earth rotation, and climate models, are examined. In this way, the contribution of each measurement technique to interpreting the low degree surface mass density of the Earth is shown. Especially, we evaluate an usefulness of several climate models from the Coupled Model Intercomparison Project phase 5 (CMIP5) to determine the low degree Earth's gravity coefficients using GRACE satellite observations. To do that, Terrestrial Water Storage (TWS) changes from several CMIP5 climate models are determined and then these simulated data are compared with the GRACE observations. Spherical harmonics ΔC21, ΔS21, and ΔC20 changes are calculated as the sum of atmosphere and ocean mass effect (GAC values) taken from GRACE and a land surface hydrological estimate from the selected CMIP5 climate models. Low degree Stokes coefficients of the surface mass density determined from GRACE, SLR, GNSS, Earth rotation measurements and climate models are compared to each other in order to assess their consistency. The comparison is done by using different types of statistical and signal processing methods.

  5. Visualizing the Impacts of Movement Infrastructures on Social Inclusion: Graph-Based Methods for Observing Community Formations in Contrasting Geographic Contexts

    Directory of Open Access Journals (Sweden)

    Jamie O'Brien

    2017-12-01

    Full Text Available In this article we describe some innovative methods for observing the possible impacts of roads, junctions and pathways (movement infrastructures, on community life in terms of their affordances and hindrances for social connectivity. In seeking to observe these impacts, we combined a range of visualization research methods, based on qualitative points-data mapping, graphic representation and urban morphological analysis at local and global geographic scales. Our overall aim in this study was to develop exploratory methods for combining and visualizing various kinds of data that relate to urban community formations in contrasting urban contexts. We focused our enquiry on the perspectives of adolescents in two urban contexts: Liverpool, UK, and Medellín, Colombia. While they contrast in their geo-political and cultural characteristics, these two cities each present polarized socio-economic inequalities across distinctive spatial patterns. We found that adolescents in these cities offer generally localized, pedestrian perspectives of their local areas, and unique insights into the opportunities and challenges for place-making in their local community spaces. We gathered the communities’ local perspectives through map-making workshops, in which participants used given iconographic symbols to select and weight the social and structural assets that they deemed to be significant features of their community spaces. We then sampled and visualized these selective points data to observe ways in which local community assets relate to infrastructural affordances for movement (in terms of network integration. This analysis was based on the theory and method of Space Syntax, which provides a model of affordances for movement across the urban network over various scales of network configuration. In particular, we sought to determine how city-scale movement infrastructures interact with local-scale infrastructures, and to develop methods for observing ways

  6. Electron microscope observations of impact crater debris amongst contaminating particulates on materials surfaces exposed in space in low-Earth orbit

    Science.gov (United States)

    Murr, L. E.; Rivas, J. M.; Quinones, S.; Niou, C.-S.; Advani, A. H.; Marquez, B.

    1993-01-01

    Debris particles extracted from a small sampling region on the leading edge of the Long Duration Exposure Facility (LDEF) spacecraft have been examined by analytical transmission electron microscopy and the elemental frequency observed by energy-dispersive X-ray spectrometry and compared with upper atmosphere (Earth) particle elemental frequency and the average elemental compositions of interplanetary dust particles. A much broader elemental distribution was observed for the exposed spacecraft surface debris milieu. Numerous metal microfragment analyses, particularly aluminum and stainless steel, were compared with scanning electron microscope observations-of impact crater features, and the corresponding elemental spectra on selected LDEF aluminium tray clamps and stainless steel bolts. The compositions and melt features for these impact craters and ejecta have been shown to be consistent with microcrystalline debris fragments in the case of aluminum, and these observations suggest an ever changing debris milieu on exposed surfaces for space craft and space system materials.

  7. Ground-based observations of exoplanet atmospheres

    NARCIS (Netherlands)

    Mooij, Ernst Johan Walter de

    2011-01-01

    This thesis focuses on the properties of exoplanet atmospheres. The results for ground-based near-infrared secondary eclipse observations of three different exoplanets, TrES-3b, HAT-P-1b and WASP-33b, are presented which have been obtained with ground-based telescopes as part of the GROUSE project.

  8. Validation of ACE-FTS v2.2 measurements of HCl, HF, CCl3F and CCl2F2 using space-, balloon- and ground-based instrument observations

    Directory of Open Access Journals (Sweden)

    C. Servais

    2008-10-01

    Full Text Available Hydrogen chloride (HCl and hydrogen fluoride (HF are respectively the main chlorine and fluorine reservoirs in the Earth's stratosphere. Their buildup resulted from the intensive use of man-made halogenated source gases, in particular CFC-11 (CCl3F and CFC-12 (CCl2F2, during the second half of the 20th century. It is important to continue monitoring the evolution of these source gases and reservoirs, in support of the Montreal Protocol and also indirectly of the Kyoto Protocol. The Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS is a space-based instrument that has been performing regular solar occultation measurements of over 30 atmospheric gases since early 2004. In this validation paper, the HCl, HF, CFC-11 and CFC-12 version 2.2 profile data products retrieved from ACE-FTS measurements are evaluated. Volume mixing ratio profiles have been compared to observations made from space by MLS and HALOE, and from stratospheric balloons by SPIRALE, FIRS-2 and Mark-IV. Partial columns derived from the ACE-FTS data were also compared to column measurements from ground-based Fourier transform instruments operated at 12 sites. ACE-FTS data recorded from March 2004 to August 2007 have been used for the comparisons. These data are representative of a variety of atmospheric and chemical situations, with sounded air masses extending from the winter vortex to summer sub-tropical conditions. Typically, the ACE-FTS products are available in the 10–50 km altitude range for HCl and HF, and in the 7–20 and 7–25 km ranges for CFC-11 and -12, respectively. For both reservoirs, comparison results indicate an agreement generally better than 5–10% above 20 km altitude, when accounting for the known offset affecting HALOE measurements of HCl and HF. Larger positive differences are however found for comparisons with single profiles from FIRS-2 and SPIRALE. For CFCs, the few coincident measurements available suggest that the differences

  9. Ratioing methods for in-flight response calibration of space-based spectro-radiometers, operating in the solar spectral region

    Science.gov (United States)

    Lobb, Dan

    2017-11-01

    One of the most significant problems for space-based spectro-radiometer systems, observing Earth from space in the solar spectral band (UV through short-wave IR), is in achievement of the required absolute radiometric accuracy. Classical methods, for example using one or more sun-illuminated diffusers as reflectance standards, do not generally provide methods for monitoring degradation of the in-flight reference after pre-flight characterisation. Ratioing methods have been proposed that provide monitoring of degradation of solar attenuators in flight, thus in principle allowing much higher confidence in absolute response calibration. Two example methods are described. It is shown that systems can be designed for relatively low size and without significant additions to the complexity of flight hardware.

  10. Future of Space Astronomy: A Global Road Map for the Next Decades

    Science.gov (United States)

    Ubertini, Pietro; Gehrels, Neil; Corbett, Ian; DeBernardis, Paolo; Machado, Marcos; Griffin, Matt; Hauser, Michael; Manchanda, Ravinder K.; Kawai, Nobuyuki; Zhang, Shuang-Nan; hide

    2012-01-01

    The use of space techniques continues to play a key role in the advance of astrophysics by providing access to the entire electromagnetic spectrum from the radio observations to the high energy gamma rays. The increasing size, complexity and cost of large space observatories places a growing emphasis on international collaboration. Furthermore, combining existing and future datasets from space and ground based observatories is an emerging mode of powerful and relatively inexpensive research to address problems that can only be tackled by the application of large multi-wavelength observations. If the present set of space and ground-based astronomy facilities today is impressive and complete, with space and ground based astronomy telescopes nicely complementing each other, the situation becomes concerning and critical in the next 10-20 years. In fact, only a few main space missions are planned, possibly restricted to JWST and, perhaps, WFIRST and SPICA, since no other main facilities are already recommended. A "Working Group on the Future of Space Astronomy" was established at the 38th COSPAR Assembly held in Bremen, Germany in July 2010. The purpose of this Working Group was to establish a roadmap for future major space missions to complement future large ground-based telescopes. This paper presents the results of this study including a number of recommendations and a road map for the next decades of Space Astronomy research.

  11. Gender-sensitive observations in public spaces as a teaching tool

    NARCIS (Netherlands)

    Droogleever Fortuijn, J.

    2009-01-01

    Public spaces can be seen as arenas where gendered social roles, relations and identities are (re)produced, represented and contested. Because of their (assumed) public character - crowded, open, accessible and visible - these spaces are extremely useful as «observatories» for teaching and learning

  12. Flexible Graphene-based Energy Storage Devices for Space Application Project

    Science.gov (United States)

    Calle, Carlos I.

    2014-01-01

    Develop prototype graphene-based reversible energy storage devices that are flexible, thin, lightweight, durable, and that can be easily attached to spacesuits, rovers, landers, and equipment used in space.

  13. Magnetospheric Multiscale (MMS) Observation of Plasma Velocity-Space Cascade Processes

    Science.gov (United States)

    Parashar, T. N.; Servidio, S.; Matthaeus, W. H.; Chasapis, A.; Perrone, D.; Valentini, F.; Veltri, P.; Gershman, D. J.; Schwartz, S. J.; Giles, B. L.; Fuselier, S. A.; Phan, T.; Burch, J.

    2017-12-01

    Plasma turbulence is investigated using high-resolution ion velocity distributions, measured by theMagnetospheric Multiscale Mission (MMS) in the Earth's magnetosheath. The particle distributionmanifests large fluctuations, suggesting a cascade-like process in velocity space, invoked by theoristsfor many years. This complex velocity space structure is investigated using a three-dimensional Hermitetransform that reveals a power law distribution of moments. A Kolmogorov approach leads directlyto a range of predictions for this phase-space cascade. The scaling theory is in agreement withobservations, suggesting a new path for the study of plasma turbulence in weakly collisional spaceand astrophysical plasmas.

  14. Extreme Space Weather Events: From Cradle to Grave

    Science.gov (United States)

    Riley, Pete; Baker, Dan; Liu, Ying D.; Verronen, Pekka; Singer, Howard; Güdel, Manuel

    2018-02-01

    Extreme space weather events, while rare, can have a substantial impact on our technologically-dependent society. And, although such events have only occasionally been observed, through careful analysis of a wealth of space-based and ground-based observations, historical records, and extrapolations from more moderate events, we have developed a basic picture of the components required to produce them. Several key issues, however, remain unresolved. For example, what limits are imposed on the maximum size of such events? What are the likely societal consequences of a so-called "100-year" solar storm? In this review, we summarize our current scientific understanding about extreme space weather events as we follow several examples from the Sun, through the solar corona and inner heliosphere, across the magnetospheric boundary, into the ionosphere and atmosphere, into the Earth's lithosphere, and, finally, its impact on man-made structures and activities, such as spacecraft, GPS signals, radio communication, and the electric power grid. We describe preliminary attempts to provide probabilistic forecasts of extreme space weather phenomena, and we conclude by identifying several key areas that must be addressed if we are better able to understand, and, ultimately, predict extreme space weather events.

  15. Properties of the nuclei and comae of 10 ecliptic comets from Hubble Space Telescope multi-orbit observations

    Science.gov (United States)

    Lamy, P. L.; Toth, I.; Weaver, H. A.; A'Hearn, M. F.; Jorda, L.

    2011-04-01

    We report on our on-going effort to detect and characterize cometary nuclei with the Hubble Space Telescope (HST). During cycle 9 (2000 July to 2001 June), we performed multi-orbit observations of 10 ecliptic comets with the Wide Field Planetary Camera 2. Nominally, eight contiguous orbits covering a time interval of ˜11 h were devoted to each comet but a few orbits were occasionally lost. In addition to the standard R band, we could additionally observe four of them in the V band and the two brightest ones in the B band. Time series photometry was used to constrain the size, shape and rotational period of the 10 nuclei. Assuming a geometric albedo of 0.04 for the R band, a linear phase law with a coefficient of 0.04 mag deg-1 and an opposition effect similar to that of comet 19P/Borrelly, we determined the following mean values of the effective radii 47P/Ashbrook-Jackson: 2.86±0.08 km, 61P/Shajn-Schaldach: 0.62±0.02 km, 70P/Kojima: 1.83±0.05 km, 74P/Smirnova-Chernykh: 2.23±0.04 km, 76P/West-Kohoutek-Ikemura: 0.30±0.02 km, 82P/Gehrels 3: 0.69±0.02 km, 86P/Wild 3: 0.41±0.03 km, 87P/Bus: 0.270.01 km, 110P/Hartley 3: 2.15±0.04 km and 147P/Kushida-Muramatsu: 0.21±0.01 km. Because of the limited time coverage (˜11 h), the rotational periods could not be accurately determined, multiple solutions were sometime found and three periods were not constrained at all. Our estimates range from ˜5 to ˜32 h. The lower limits for the ratio a/b of the semi-axis of the equivalent spheroids range from 1.10 (70P) to 2.20 (87P). The four nuclei for which we could measure (V-R) are all significantly redder than the Sun, with 86P/Wild 3 (V-R) = 0.86 ± 0.10 appearing as an ultrared object. We finally determined the dust activity parameter Afρ of their coma in the R band, the colour indices and the reflectivity spectra of four of them. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at Space Telescope Science Institute, which is operated by the

  16. Bumpless Transfer between Observer-based Gain Scheduled Controllers

    DEFF Research Database (Denmark)

    Bendtsen, Jan Dimon; Stoustrup, Jakob; Trangbæk, Klaus

    2005-01-01

    This paper deals with bumpless transfer between a number of observer-based controllers in a gain scheduling architecture. Linear observer-based controllers are designed for a number of linear approximations of a nonlinear system in a set of operating points, and gain scheduling control can...

  17. A method of camera calibration in the measurement process with reference mark for approaching observation space target

    Science.gov (United States)

    Zhang, Hua; Zeng, Luan

    2017-11-01

    Binocular stereoscopic vision can be used for space-based space targets near observation. In order to solve the problem that the traditional binocular vision system cannot work normally after interference, an online calibration method of binocular stereo measuring camera with self-reference is proposed. The method uses an auxiliary optical imaging device to insert the image of the standard reference object into the edge of the main optical path and image with the target on the same focal plane, which is equivalent to a standard reference in the binocular imaging optical system; When the position of the system and the imaging device parameters are disturbed, the image of the standard reference will change accordingly in the imaging plane, and the position of the standard reference object does not change. The camera's external parameters can be re-calibrated by the visual relationship of the standard reference object. The experimental results show that the maximum mean square error of the same object can be reduced from the original 72.88mm to 1.65mm when the right camera is deflected by 0.4 degrees and the left camera is high and low with 0.2° rotation. This method can realize the online calibration of binocular stereoscopic vision measurement system, which can effectively improve the anti - jamming ability of the system.

  18. Process observation in fiber laser-based selective laser melting

    Science.gov (United States)

    Thombansen, Ulrich; Gatej, Alexander; Pereira, Milton

    2015-01-01

    The process observation in selective laser melting (SLM) focuses on observing the interaction point where the powder is processed. To provide process relevant information, signals have to be acquired that are resolved in both time and space. Especially in high-power SLM, where more than 1 kW of laser power is used, processing speeds of several meters per second are required for a high-quality processing results. Therefore, an implementation of a suitable process observation system has to acquire a large amount of spatially resolved data at low sampling speeds or it has to restrict the acquisition to a predefined area at a high sampling speed. In any case, it is vitally important to synchronously record the laser beam position and the acquired signal. This is a prerequisite that allows the recorded data become information. Today, most SLM systems employ f-theta lenses to focus the processing laser beam onto the powder bed. This report describes the drawbacks that result for process observation and suggests a variable retro-focus system which solves these issues. The beam quality of fiber lasers delivers the processing laser beam to the powder bed at relevant focus diameters, which is a key prerequisite for this solution to be viable. The optical train we present here couples the processing laser beam and the process observation coaxially, ensuring consistent alignment of interaction zone and observed area. With respect to signal processing, we have developed a solution that synchronously acquires signals from a pyrometer and the position of the laser beam by sampling the data with a field programmable gate array. The relevance of the acquired signals has been validated by the scanning of a sample filament. Experiments with grooved samples show a correlation between different powder thicknesses and the acquired signals at relevant processing parameters. This basic work takes a first step toward self-optimization of the manufacturing process in SLM. It enables the

  19. Space nuclear power systems for extraterrestrial basing

    International Nuclear Information System (INIS)

    Lance, J.R.; Chi, J.W.H.

    1989-01-01

    Previous studies of nuclear and non-nuclear power systems for lunar bases are compared with recent studies by others. Power levels from tens of kW e for early base operation up to 2000 kW e for a self-sustaining base with a Closed Environment Life Support System (CELSS) are considered. Permanent lunar or Martian bases will require the use of multiple nuclear units connected to loads with a power transmission and distribution system analogous to earth-based electric utility systems. A methodology used for such systems is applied to the lunar base system to examine the effects of adding 100 kW e SP-100 class and/or larger nuclear units when a reliability criterion is imposed. The results show that resource and logistic burdens can be reduced by using 1000 kW e units early in the base growth scenario without compromising system reliability. Therefore, both technologies being developed in two current programs (SP-100 and NERVA Derivative Reactor (NDR) technology for space power) can be used effectively for extraterrestrial base power systems. Recent developments in NDR design that result in major reductions in reactor mass are also described. (author)

  20. Nuclear reactor power as applied to a space-based radar mission

    Science.gov (United States)

    Jaffe, L.; Beatty, R.; Bhandari, P.; Chow, E.; Deininger, W.; Ewell, R.; Fujita, T.; Grossman, M.; Bloomfield, H.; Heller, J.

    1988-01-01

    A space-based radar mission and spacecraft are examined to determine system requirements for a 300 kWe space nuclear reactor power system. The spacecraft configuration and its orbit, launch vehicle, and propulsion are described. Mission profiles are addressed, and storage in assembly orbit is considered. Dynamics and attitude control and the problems of nuclear and thermal radiation are examined.

  1. 16 year climatology of cirrus clouds over a tropical station in southern India using ground and space-based lidar observations

    Science.gov (United States)

    Pandit, A. K.; Gadhavi, H. S.; Venkat Ratnam, M.; Raghunath, K.; Rao, S. V. B.; Jayaraman, A.

    2015-06-01

    16 year (1998-2013) climatology of cirrus clouds and their macrophysical (base height, top height and geometrical thickness) and optical properties (cloud optical thickness) observed using a ground-based lidar over Gadanki (13.5° N, 79.2° E), India, is presented. The climatology obtained from the ground-based lidar is compared with the climatology obtained from seven and half years (June 2006-December 2013) of Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP) observations. A very good agreement is found between the two climatologies in spite of their opposite viewing geometries and difference in sampling frequencies. Nearly 50-55% of cirrus clouds were found to possess geometrical thickness less than 2 km. Ground-based lidar is found to detect more number of sub-visible clouds than CALIOP which has implications for global warming studies as sub-visible cirrus clouds have significant positive radiative forcing. Cirrus clouds with mid-cloud temperatures between -50 to -70 °C have a mean geometrical thickness greater than 2 km in contrast to the earlier reported value of 1.7 km. Trend analyses reveal a statistically significant increase in the altitude of sub-visible cirrus clouds which is consistent with the recent climate model simulations. Also, the fraction of sub-visible cirrus cloud is found to be increasing during the last sixteen years (1998 to 2013) which has implications to the temperature and water vapour budget in the tropical tropopause layer.

  2. TiAu-based micro-calorimeters for space applications

    International Nuclear Information System (INIS)

    Dirks, B.P.F.; Popescu, M.; Bruijn, M.; Gottardi, L.; Hoevers, H.F.C.; Korte, P.A.J. de; Kuur, J. van der; Ridder, M.; Takei, Y.

    2009-01-01

    We present the latest results of the performance of micro-calorimeters based on transition edge sensors (TESs) for space applications. Sensors based on TiAu superconductive layers with Cu/Bi absorbers are discussed and have been characterized. Different coupling schemes between absorber and TES have been tested leading to an optimal (preferred) design for a new batch of arrays. We discuss the progress on array development for the International X-ray Observatory (IXO) in terms of pixel uniformity and filling factor. Inter-pixel cross-talk is discussed as well.

  3. Space-Based CO2 Active Optical Remote Sensing using 2-μm Triple-Pulse IPDA Lidar

    Science.gov (United States)

    Singh, Upendra; Refaat, Tamer; Ismail, Syed; Petros, Mulugeta

    2017-04-01

    Sustained high-quality column CO2 measurements from space are required to improve estimates of regional and global scale sources and sinks to attribute them to specific biogeochemical processes for improving models of carbon-climate interactions and to reduce uncertainties in projecting future change. Several studies show that space-borne CO2 measurements offer many advantages particularly over high altitudes, tropics and southern oceans. Current satellite-based sensing provides rapid CO2 monitoring with global-scale coverage and high spatial resolution. However, these sensors are based on passive remote sensing, which involves limitations such as full seasonal and high latitude coverage, poor sensitivity to the lower atmosphere, retrieval complexities and radiation path length uncertainties. CO2 active optical remote sensing is an alternative technique that has the potential to overcome these limitations. The need for space-based CO2 active optical remote sensing using the Integrated Path Differential Absorption (IPDA) lidar has been advocated by the Advanced Space Carbon and Climate Observation of Planet Earth (A-Scope) and Active Sensing of CO2 Emission over Nights, Days, and Seasons (ASCENDS) studies in Europe and the USA. Space-based IPDA systems can provide sustained, high precision and low-bias column CO2 in presence of thin clouds and aerosols while covering critical regions such as high latitude ecosystems, tropical ecosystems, southern ocean, managed ecosystems, urban and industrial systems and coastal systems. At NASA Langley Research Center, technology developments are in progress to provide high pulse energy 2-μm IPDA that enables optimum, lower troposphere weighted column CO2 measurements from space. This system provides simultaneous ranging; information on aerosol and cloud distributions; measurements over region of broken clouds; and reduces influences of surface complexities. Through the continual support from NASA Earth Science Technology Office

  4. Motion state analysis of space target based on optical cross section

    Science.gov (United States)

    Tian, Qichen; Li, Zhi; Xu, Can; Liu, Chenghao

    2017-10-01

    In order to solve the problem that the movement state analysis method of the space target based on OCS is not related to the real motion state. This paper proposes a method based on OCS for analyzing the state of space target motion. This paper first establish a three-dimensional model of real STSS satellite, then change the satellite's surface into element, and assign material to each panel according to the actual conditions of the satellite. This paper set up a motion scene according to the orbit parameters of STSS satellite in STK, and the motion states are set to three axis steady state and slowly rotating unstable state respectively. In these two states, the occlusion condition of the surface element is firstly determined, and the effective face element is selected. Then, the coordinates of the observation station and the solar coordinates in the satellite body coordinate system are input into the OCS calculation program, and the OCS variation curves of the three axis steady state and the slow rotating unstable state STSS satellite are obtained. Combining the satellite surface structure and the load situation, the OCS change curve of the three axis stabilized satellite is analyzed, and the conclude that the OCS curve fluctuates up and down when the sunlight is irradiated to the load area; By using Spectral analysis method, autocorrelation analysis and the cross residual method, the rotation speed of OCS satellite in slow rotating unstable state is analyzed, and the rotation speed of satellite is successfully reversed. By comparing the three methods, it is found that the cross residual method is more accurate.

  5. Ground and Space Radar Volume Matching and Comparison Software

    Science.gov (United States)

    Morris, Kenneth; Schwaller, Mathew

    2010-01-01

    This software enables easy comparison of ground- and space-based radar observations. The software was initially designed to compare ground radar reflectivity from operational, ground based Sand C-band meteorological radars with comparable measurements from the Tropical Rainfall Measuring Mission (TRMM) satellite s Precipitation Radar (PR) instrument. The software is also applicable to other ground-based and space-based radars. The ground and space radar volume matching and comparison software was developed in response to requirements defined by the Ground Validation System (GVS) of Goddard s Global Precipitation Mission (GPM) project. This software innovation is specifically concerned with simplifying the comparison of ground- and spacebased radar measurements for the purpose of GPM algorithm and data product validation. This software is unique in that it provides an operational environment to routinely create comparison products, and uses a direct geometric approach to derive common volumes of space- and ground-based radar data. In this approach, spatially coincident volumes are defined by the intersection of individual space-based Precipitation Radar rays with the each of the conical elevation sweeps of the ground radar. Thus, the resampled volume elements of the space and ground radar reflectivity can be directly compared to one another.

  6. "Slow-scanning" in Ground-based Mid-infrared Observations

    Science.gov (United States)

    Ohsawa, Ryou; Sako, Shigeyuki; Miyata, Takashi; Kamizuka, Takafumi; Okada, Kazushi; Mori, Kiyoshi; Uchiyama, Masahito S.; Yamaguchi, Junpei; Fujiyoshi, Takuya; Morii, Mikio; Ikeda, Shiro

    2018-04-01

    Chopping observations with a tip-tilt secondary mirror have conventionally been used in ground-based mid-infrared observations. However, it is not practical for next generation large telescopes to have a large tip-tilt mirror that moves at a frequency larger than a few hertz. We propose an alternative observing method, a "slow-scanning" observation. Images are continuously captured as movie data, while the field of view is slowly moved. The signal from an astronomical object is extracted from the movie data by a low-rank and sparse matrix decomposition. The performance of the "slow-scanning" observation was tested in an experimental observation with Subaru/COMICS. The quality of a resultant image in the "slow-scanning" observation was as good as in a conventional chopping observation with COMICS, at least for a bright point-source object. The observational efficiency in the "slow-scanning" observation was better than that in the chopping observation. The results suggest that the "slow-scanning" observation can be a competitive method for the Subaru telescope and be of potential interest to other ground-based facilities to avoid chopping.

  7. Trajectory Planning of 7-DOF Space Manipulator for Minimizing Base Disturbance

    Directory of Open Access Journals (Sweden)

    Qiang Zhang

    2016-03-01

    Full Text Available In the free-floating mode, there is intense dynamic coupling existing between the space manipulator and the base, and the base attitude may change while performing a motion with its manipulator. Therefore, it is necessary to reduce the interference that resulted from the manipulator movement. For planning trajectories of the space manipulator with 7 degrees of freedom (7-DOF, simulated annealing particle swarm optimization (SAPSO algorithm is presented in the paper. Firstly, kinematics equations are setup. Secondly, the joint functions are parameterized by sinusoidal functions, and the objective function is defined according to the motion constraints of manipulator and accuracy requirements of the base attitude. Finally, SAPSO algorithm is used to search the optimal trajectory. The simulation results verify the proposed method.

  8. Molecular basis sets - a general similarity-based approach for representing chemical spaces.

    Science.gov (United States)

    Raghavendra, Akshay S; Maggiora, Gerald M

    2007-01-01

    A new method, based on generalized Fourier analysis, is described that utilizes the concept of "molecular basis sets" to represent chemical space within an abstract vector space. The basis vectors in this space are abstract molecular vectors. Inner products among the basis vectors are determined using an ansatz that associates molecular similarities between pairs of molecules with their corresponding inner products. Moreover, the fact that similarities between pairs of molecules are, in essentially all cases, nonzero implies that the abstract molecular basis vectors are nonorthogonal, but since the similarity of a molecule with itself is unity, the molecular vectors are normalized to unity. A symmetric orthogonalization procedure, which optimally preserves the character of the original set of molecular basis vectors, is used to construct appropriate orthonormal basis sets. Molecules can then be represented, in general, by sets of orthonormal "molecule-like" basis vectors within a proper Euclidean vector space. However, the dimension of the space can become quite large. Thus, the work presented here assesses the effect of basis set size on a number of properties including the average squared error and average norm of molecular vectors represented in the space-the results clearly show the expected reduction in average squared error and increase in average norm as the basis set size is increased. Several distance-based statistics are also considered. These include the distribution of distances and their differences with respect to basis sets of differing size and several comparative distance measures such as Spearman rank correlation and Kruscal stress. All of the measures show that, even though the dimension can be high, the chemical spaces they represent, nonetheless, behave in a well-controlled and reasonable manner. Other abstract vector spaces analogous to that described here can also be constructed providing that the appropriate inner products can be directly

  9. 48 CFR 1812.7000 - Prohibition on guaranteed customer bases for new commercial space hardware or services.

    Science.gov (United States)

    2010-10-01

    ... customer bases for new commercial space hardware or services. 1812.7000 Section 1812.7000 Federal... PLANNING ACQUISITION OF COMMERCIAL ITEMS Commercial Space Hardware or Services 1812.7000 Prohibition on guaranteed customer bases for new commercial space hardware or services. Public Law 102-139, title III...

  10. Global Trends in Space Access and Utilization

    Science.gov (United States)

    Rahman, Shamim A.; Keim, Nicholas S.; Zeender, Peter E.

    2010-01-01

    In the not-so-distant past, space access and air/space technology superiority were within the purview of the U.S. and former Soviet Union's respective space agencies, both vying for global leadership in space exploitation. In more recent years, with the emergence of the European Space Agency (ESA) member countries and Asian countries joining the family of space-faring nations, it is truer now more than ever that space access and utilization has become a truly global enterprise. In fact, according to the Space Report 2007, this enterprise is a $251-billion economy. It is possible to gauge the vitality of worldwide efforts from open sources in today's transparent, media-based society. In particular, print and web broadcasters regularly report and catalog global space activities for defense and civil purposes. For the purposes of this paper, a representative catalog of missions is used to illustrate the nature of the emerging "globalization." This paper highlights global trends in terms of not only the providers of space access, but also the end-users for the various recently accomplished missions. With well over 50 launches per year, in recent years, the launch-log reveals a surprising percentage of "cooperative or co-dependent missions" where different agencies, countries, and/or commercial entities are so engaged presumably to the benefit of all who participate. Statistics are cited and used to show that recently over d0% of the 50-plus missions involved multiple nations working collectively to deliver payloads to orbit. Observers, space policy professionals, and space agency leaders have eloquently proposed that it might require the combined resources and talents of multiple nations to advance human exploration goals beyond low earth orbit. This paper does not intend to offer new information with respect to whether international collaboration is necessary but to observe that, in continuing to monitor global trends, the results seem to support the thesis that a

  11. Imaging the Surfaces of Stars from Space

    Science.gov (United States)

    Carpenter, Kenneth; Rau, Gioia

    2018-04-01

    Imaging of Stellar Surfacess has been dominated to-date by ground-based observations, but space-based facilities offer tremendous potential for extending the wavelength coverage and ultimately the resolution of such efforts. We review the imaging accomplished so far from space and then talk about exciting future prospects. The earliest attempts from space indirectly produced surface maps via the Doppler Imaging Technique, using UV spectra obtained with the International Ultraviolet Explorer (IUE). Later, the first direct UV images were obtained with the Hubble Space Telescope (HST), of Mira and Betelgeuse, using the Faint Object Camera (FOC). We will show this work and then investigate prospects for IR imaging with the James Webb Space Telescope (JWST). The real potential of space-based Imaging of Stellar Surfacess, however, lies in the future, when large-baseline Fizeau interferometers, such as the UV-optical Stellar Imager (SI) Vision Mission, with a 30-element array and 500m max baseline, are flown. We describe SI and its science goals, which include 0.1 milli-arcsec spectral Imaging of Stellar Surfacess and the probing of internal structure and flows via asteroseismology.

  12. Free locally convex spaces with a small base

    Czech Academy of Sciences Publication Activity Database

    Gabriyelyan, S.; Kąkol, Jerzy

    2017-01-01

    Roč. 111, č. 2 (2017), s. 575-585 ISSN 1578-7303 R&D Projects: GA ČR GF16-34860L Institutional support: RVO:67985840 Keywords : compact resolution * free locally convex space * G-base Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.690, year: 2016 http://link.springer.com/article/10.1007%2Fs13398-016-0315-1

  13. Self-excitation of space charge waves

    DEFF Research Database (Denmark)

    Lyuksyutov, Sergei; Buchhave, Preben; Vasnetsov, Mikhail

    1997-01-01

    We report a direct observation of space charge waves in photorefractive crystals with point group 23 (sillenites) based on their penetration into an area with uniform light illumination. It is shown experimentally that the quality factor of the waves increases substantially with respect to what c...... current theory predicts [B. Sturman el al., Appl. Phys. A 55, 235 (1992)]. This results in the appearance of strong spontaneous beams caused by space charge wave self-excitation....

  14. A Framework for Orbital Performance Evaluation in Distributed Space Missions for Earth Observation

    Science.gov (United States)

    Nag, Sreeja; LeMoigne-Stewart, Jacqueline; Miller, David W.; de Weck, Olivier

    2015-01-01

    Distributed Space Missions (DSMs) are gaining momentum in their application to earth science missions owing to their unique ability to increase observation sampling in spatial, spectral and temporal dimensions simultaneously. DSM architectures have a large number of design variables and since they are expected to increase mission flexibility, scalability, evolvability and robustness, their design is a complex problem with many variables and objectives affecting performance. There are very few open-access tools available to explore the tradespace of variables which allow performance assessment and are easy to plug into science goals, and therefore select the most optimal design. This paper presents a software tool developed on the MATLAB engine interfacing with STK, for DSM orbit design and selection. It is capable of generating thousands of homogeneous constellation or formation flight architectures based on pre-defined design variable ranges and sizing those architectures in terms of predefined performance metrics. The metrics can be input into observing system simulation experiments, as available from the science teams, allowing dynamic coupling of science and engineering designs. Design variables include but are not restricted to constellation type, formation flight type, FOV of instrument, altitude and inclination of chief orbits, differential orbital elements, leader satellites, latitudes or regions of interest, planes and satellite numbers. Intermediate performance metrics include angular coverage, number of accesses, revisit coverage, access deterioration over time at every point of the Earth's grid. The orbit design process can be streamlined and variables more bounded along the way, owing to the availability of low fidelity and low complexity models such as corrected HCW equations up to high precision STK models with J2 and drag. The tool can thus help any scientist or program manager select pre-Phase A, Pareto optimal DSM designs for a variety of science

  15. On the concept of survivability, with application to spacecraft and space-based networks

    International Nuclear Information System (INIS)

    Castet, Jean-Francois; Saleh, Joseph H.

    2012-01-01

    Survivability is an important attribute and requirement for military systems. Recently, survivability has become increasingly important for public infrastructure systems as well. In this work, we bring considerations of survivability to bear on space systems. We develop a conceptual framework and quantitative analyses based on stochastic Petri nets (SPN) to characterize and compare the survivability of different space architectures. The architectures here considered are a monolith spacecraft and a space-based network. To build the stochastic Petri net models for the degradations and failures of these two architectures, we conducted statistical analyses of historical multi-state failure data of spacecraft subsystems, and we assembled these subsystems, and their SPN models, in ways to create our monolith and networked systems. Preliminary results indicate, and quantify the extent to which, a space-based network is more survivable than the monolith spacecraft with respect to on-orbit anomalies and failures. For space systems, during the design and acquisition process, different architectures are benchmarked against several metrics; we argue that if survivability is not accounted for, then the evaluation process is likely to be biased in favor of the traditional dominant design, namely the monolith spacecraft. If however in a given context, survivability is a critical requirement for a customer, the survivability framework here proposed, and the stochastic modeling capability developed, can demonstrate the extent to which a networked space architecture may better satisfy this requirement than a monolith spacecraft. These results should be of interest to operators whose space assets require high levels of survivability, especially in the light of emerging threats.

  16. Space Based Infrared System High (SBIRS High)

    Science.gov (United States)

    2015-12-01

    elements (five SMGTs) for the S2E2 Mobile Ground System. ​ SBIRS Block Buy (GEO 5-6) The GEO 5-6 Tech Refresh (TR) Engineering Change Proposal was...Selected Acquisition Report (SAR) RCS: DD-A&T(Q&A)823-210 Space Based Infrared System High ( SBIRS High) As of FY 2017 President’s Budget Defense...Acquisition Management Information Retrieval (DAMIR) March 23, 2016 11:24:26 UNCLASSIFIED SBIRS High December 2015 SAR March 23, 2016 11:24:26

  17. A Strategy for Thailand's Space Technology Development: National Space Program (NSP)

    Science.gov (United States)

    Pimnoo, Ammarin; Purivigraipong, Somphop

    2016-07-01

    The Royal Thai Government has established the National Space Policy Committee (NSPC) with mandates for setting policy and strategy. The NSPC is considering plans and budget allocation for Thai space development. NSPC's goal is to promote the utilization of space technology in a manner that is congruent with the current situation and useful for the economy, society, science, technology, educational development and national security. The first proposed initiative of the National Space Program (NSP) is co-development of THEOS-2, a next-generation satellite system that includes Thailand's second and third earth observation satellite (THAICHOTE-2 and THAICHOTE-3). THEOS-1 or THAICHOTE-1 was the first Earth Observation Satellite of Thailand launched in 2008. At present, the THAICHOTE-1 is over the lifetime, therefore the THEOS-2 project has been established. THEOS-2 is a complete Earth Observation System comprising THAICHOTE-2&3 as well as ground control segment and capacity building. Thus, NSPC has considered that Thailand should manage the space system. Geo-Informatics and Space Technology Development Agency (GISTDA) has been assigned to propose the initiative National Space Program (NSP). This paper describes the strategy of Thailand's National Space Program (NSP) which will be driven by GISTDA. First, NSP focuses on different aspects of the utilization of space on the basis of technology, innovation, knowledge and manpower. It contains driving mechanisms related to policy, implementation and use in order to promote further development. The Program aims to increase economic competitiveness, reduce social disparity, and improve social security, natural resource management and environmental sustainability. The NSP conceptual framework includes five aspects: communications satellites, earth observation satellite systems, space economy, space exploration and research, and NSP administration. THEOS-2 is considered a part of NSP with relevance to the earth observation

  18. Construction of Orthonormal Piecewise Polynomial Scaling and Wavelet Bases on Non-Equally Spaced Knots

    Directory of Open Access Journals (Sweden)

    Jean Pierre Astruc

    2007-01-01

    Full Text Available This paper investigates the mathematical framework of multiresolution analysis based on irregularly spaced knots sequence. Our presentation is based on the construction of nested nonuniform spline multiresolution spaces. From these spaces, we present the construction of orthonormal scaling and wavelet basis functions on bounded intervals. For any arbitrary degree of the spline function, we provide an explicit generalization allowing the construction of the scaling and wavelet bases on the nontraditional sequences. We show that the orthogonal decomposition is implemented using filter banks where the coefficients depend on the location of the knots on the sequence. Examples of orthonormal spline scaling and wavelet bases are provided. This approach can be used to interpolate irregularly sampled signals in an efficient way, by keeping the multiresolution approach.

  19. An adaptive process-based cloud infrastructure for space situational awareness applications

    Science.gov (United States)

    Liu, Bingwei; Chen, Yu; Shen, Dan; Chen, Genshe; Pham, Khanh; Blasch, Erik; Rubin, Bruce

    2014-06-01

    Space situational awareness (SSA) and defense space control capabilities are top priorities for groups that own or operate man-made spacecraft. Also, with the growing amount of space debris, there is an increase in demand for contextual understanding that necessitates the capability of collecting and processing a vast amount sensor data. Cloud computing, which features scalable and flexible storage and computing services, has been recognized as an ideal candidate that can meet the large data contextual challenges as needed by SSA. Cloud computing consists of physical service providers and middleware virtual machines together with infrastructure, platform, and software as service (IaaS, PaaS, SaaS) models. However, the typical Virtual Machine (VM) abstraction is on a per operating systems basis, which is at too low-level and limits the flexibility of a mission application architecture. In responding to this technical challenge, a novel adaptive process based cloud infrastructure for SSA applications is proposed in this paper. In addition, the details for the design rationale and a prototype is further examined. The SSA Cloud (SSAC) conceptual capability will potentially support space situation monitoring and tracking, object identification, and threat assessment. Lastly, the benefits of a more granular and flexible cloud computing resources allocation are illustrated for data processing and implementation considerations within a representative SSA system environment. We show that the container-based virtualization performs better than hypervisor-based virtualization technology in an SSA scenario.

  20. Study on store-space assignment based on logistic AGV in e-commerce goods to person picking pattern

    Science.gov (United States)

    Xu, Lijuan; Zhu, Jie

    2017-10-01

    This paper studied on the store-space assignment based on logistic AGV in E-commerce goods to person picking pattern, and established the store-space assignment model based on the lowest picking cost, and design for store-space assignment algorithm after the cluster analysis based on similarity coefficient. And then through the example analysis, compared the picking cost between store-space assignment algorithm this paper design and according to item number and storage according to ABC classification allocation, and verified the effectiveness of the design of the store-space assignment algorithm.

  1. Applying Model Based Systems Engineering to NASA's Space Communications Networks

    Science.gov (United States)

    Bhasin, Kul; Barnes, Patrick; Reinert, Jessica; Golden, Bert

    2013-01-01

    System engineering practices for complex systems and networks now require that requirement, architecture, and concept of operations product development teams, simultaneously harmonize their activities to provide timely, useful and cost-effective products. When dealing with complex systems of systems, traditional systems engineering methodology quickly falls short of achieving project objectives. This approach is encumbered by the use of a number of disparate hardware and software tools, spreadsheets and documents to grasp the concept of the network design and operation. In case of NASA's space communication networks, since the networks are geographically distributed, and so are its subject matter experts, the team is challenged to create a common language and tools to produce its products. Using Model Based Systems Engineering methods and tools allows for a unified representation of the system in a model that enables a highly related level of detail. To date, Program System Engineering (PSE) team has been able to model each network from their top-level operational activities and system functions down to the atomic level through relational modeling decomposition. These models allow for a better understanding of the relationships between NASA's stakeholders, internal organizations, and impacts to all related entities due to integration and sustainment of existing systems. Understanding the existing systems is essential to accurate and detailed study of integration options being considered. In this paper, we identify the challenges the PSE team faced in its quest to unify complex legacy space communications networks and their operational processes. We describe the initial approaches undertaken and the evolution toward model based system engineering applied to produce Space Communication and Navigation (SCaN) PSE products. We will demonstrate the practice of Model Based System Engineering applied to integrating space communication networks and the summary of its

  2. Possible Space-Based Gravitational-Wave Observatory Mission Concept

    Science.gov (United States)

    Livas, Jeffrey C.

    2015-01-01

    The existence of gravitational waves was established by the discovery of the Binary Pulsar PSR 1913+16 by Hulse and Taylor in 1974, for which they were awarded the 1983 Nobel Prize. However, it is the exploitation of these gravitational waves for the extraction of the astrophysical parameters of the sources that will open the first new astronomical window since the development of gamma ray telescopes in the 1970's and enable a new era of discovery and understanding of the Universe. Direct detection is expected in at least two frequency bands from the ground before the end of the decade with Advanced LIGO and Pulsar Timing Arrays. However, many of the most exciting sources will be continuously observable in the band from 0.1-100 mHz, accessible only from space due to seismic noise and gravity gradients in that band that disturb groundbased observatories. This talk will discuss a possible mission concept developed from the original Laser Interferometer Space Antenna (LISA) reference mission but updated to reduce risk and cost.

  3. The daylighting dashboard - A simulation-based design analysis for daylit spaces

    Energy Technology Data Exchange (ETDEWEB)

    Reinhart, Christoph F. [Harvard University, Graduate School of Design, 48 Quincy Street, Cambridge, MA 02138 (United States); Wienold, Jan [Fraunhofer Institute for Solar Energy Systems, Heidenhofstrasse 2, 79110 Freiburg (Germany)

    2011-02-15

    This paper presents a vision of how state-of-the-art computer-based analysis techniques can be effectively used during the design of daylit spaces. Following a review of recent advances in dynamic daylight computation capabilities, climate-based daylighting metrics, occupant behavior and glare analysis, a fully integrated design analysis method is introduced that simultaneously considers annual daylight availability, visual comfort and energy use: Annual daylight glare probability profiles are combined with an occupant behavior model in order to determine annual shading profiles and visual comfort conditions throughout a space. The shading profiles are then used to calculate daylight autonomy plots, energy loads, operational energy costs and green house gas emissions. The paper then shows how simulation results for a sidelit space can be visually presented to simulation non-experts using the concept of a daylighting dashboard. The paper ends with a discussion of how the daylighting dashboard could be practically implemented using technologies that are available today. (author)

  4. A Space Based Solar Power Satellite System

    Science.gov (United States)

    Engel, J. M.; Polling, D.; Ustamujic, F.; Yaldiz, R.; et al.

    2002-01-01

    (SPoTS) supplying other satellites with energy. SPoTS is due to be commercially viable and operative in 2020. of Technology designed the SPoTS during a full-time design period of six weeks as a third year final project. The team, organized according to the principles of systems engineering, first conducted a literature study on space wireless energy transfer to select the most suitable candidates for use on the SPoTS. After that, several different system concepts have been generated and evaluated, the most promising concept being worked out in greater detail. km altitude. Each SPoTS satellite has a 50m diameter inflatable solar collector that focuses all received sunlight. Then, the received sunlight is further redirected by means of four pointing mirrors toward four individual customer satellites. A market-analysis study showed, that providing power to geo-stationary communication satellites during their eclipse would be most beneficial. At arrival at geo-stationary orbit, the focused beam has expended to such an extent that its density equals one solar flux. This means that customer satellites can continue to use their regular solar arrays during their eclipse for power generation, resulting in a satellite battery mass reduction. the customer satellites in geo-stationary orbit, the transmitted energy beams needs to be pointed with very high accuracy. Computations showed that for this degree of accuracy, sensors are needed, which are not mainstream nowadays. Therefore further research must be conducted in this area in order to make these high-accuracy-pointing systems commercially attractive for use on the SPoTS satellites around 2020. Total 20-year system lifetime cost for 18 SPoT satellites are estimated at approximately USD 6 billion [FY2001]. In order to compete with traditional battery-based satellite power systems or possible ground based wireless power transfer systems the price per kWh for the customer must be significantly lower than the present one

  5. Visible laser and superluminescent diode based free space and underwater communications

    KAUST Repository

    Ooi, Boon S.

    2017-01-30

    We report on our recent progress in high-modulation-efficiency, InGaN-based integrated waveguide modulator-laser diodes (IWM-LDs), high-speed violet and blue emitting superluminescent diodes (SLDs), InGaN-based vertical-cavity surface-emitting lasers (VCSELs), and their applications for gigahertz laser based free-space and underwater wireless optical communications.

  6. Visible laser and superluminescent diode based free space and underwater communications

    KAUST Repository

    Ooi, Boon S.

    2017-01-01

    We report on our recent progress in high-modulation-efficiency, InGaN-based integrated waveguide modulator-laser diodes (IWM-LDs), high-speed violet and blue emitting superluminescent diodes (SLDs), InGaN-based vertical-cavity surface-emitting lasers (VCSELs), and their applications for gigahertz laser based free-space and underwater wireless optical communications.

  7. Observability-Based Guidance and Sensor Placement

    Science.gov (United States)

    Hinson, Brian T.

    Control system performance is highly dependent on the quality of sensor information available. In a growing number of applications, however, the control task must be accomplished with limited sensing capabilities. This thesis addresses these types of problems from a control-theoretic point-of-view, leveraging system nonlinearities to improve sensing performance. Using measures of observability as an information quality metric, guidance trajectories and sensor distributions are designed to improve the quality of sensor information. An observability-based sensor placement algorithm is developed to compute optimal sensor configurations for a general nonlinear system. The algorithm utilizes a simulation of the nonlinear system as the source of input data, and convex optimization provides a scalable solution method. The sensor placement algorithm is applied to a study of gyroscopic sensing in insect wings. The sensor placement algorithm reveals information-rich areas on flexible insect wings, and a comparison to biological data suggests that insect wings are capable of acting as gyroscopic sensors. An observability-based guidance framework is developed for robotic navigation with limited inertial sensing. Guidance trajectories and algorithms are developed for range-only and bearing-only navigation that improve navigation accuracy. Simulations and experiments with an underwater vehicle demonstrate that the observability measure allows tuning of the navigation uncertainty.

  8. A review of ground-based heavy-ion radiobiology relevant to space radiation risk assessment: Part II. Cardiovascular and immunological effects

    Energy Technology Data Exchange (ETDEWEB)

    Blakely, Eleanor A.; Chang, Polly Y.

    2007-02-26

    The future of manned space flight depends on an analysis of the numerous potential risks of travel into deep space. Currently no radiation dose limits have been established for these exploratory missions. To set these standards more information is needed about potential acute and late effects on human physiology from appropriate radiation exposure scenarios, including pertinent radiation types and dose rates. Cancer risks have long been considered the most serious late effect from chronic daily relatively low-dose exposures to the complex space radiation environment. However, other late effects from space radiation exposure scenarios are under study in ground-based accelerator facilities and have revealed some unique particle radiation effects not observed with conventional radiations. A comprehensive review of pertinent literature that considers tissue effects of radiation leading to functional detriments in specific organ systems has recently been published (NCRP National Council on Radiation Protection and Measurements, Information Needed to Make Radiation Protection Recommendations for Space Missions Beyond Low-Earth Orbit, Report 153, Bethesda, MD, 2006). This paper highlights the review of two non-cancer concerns from this report: cardiovascular and immunological effects.

  9. Space-based visual attention: a marker of immature selective attention in toddlers?

    Science.gov (United States)

    Rivière, James; Brisson, Julie

    2014-11-01

    Various studies suggested that attentional difficulties cause toddlers' failure in some spatial search tasks. However, attention is not a unitary construct and this study investigated two attentional mechanisms: location selection (space-based attention) and object selection (object-based attention). We investigated how toddlers' attention is distributed in the visual field during a manual search task for objects moving out of sight, namely the moving boxes task. Results show that 2.5-year-olds who failed this task allocated more attention to the location of the relevant object than to the object itself. These findings suggest that in some manual search tasks the primacy of space-based attention over object-based attention could be a marker of immature selective attention in toddlers. © 2014 Wiley Periodicals, Inc.

  10. Context Matters: Systematic Observation of Place-Based Physical Activity

    Science.gov (United States)

    McKenzie, Thomas L.

    2016-01-01

    Physical activity is place-based, and being able to assess the number of people and their characteristics in specific locations is important both for public health surveillance and for practitioners in their design of physical activity spaces and programs. Although physical activity measurement has improved recently, many investigators avoid or…

  11. Design of chemical space networks using a Tanimoto similarity variant based upon maximum common substructures.

    Science.gov (United States)

    Zhang, Bijun; Vogt, Martin; Maggiora, Gerald M; Bajorath, Jürgen

    2015-10-01

    Chemical space networks (CSNs) have recently been introduced as an alternative to other coordinate-free and coordinate-based chemical space representations. In CSNs, nodes represent compounds and edges pairwise similarity relationships. In addition, nodes are annotated with compound property information such as biological activity. CSNs have been applied to view biologically relevant chemical space in comparison to random chemical space samples and found to display well-resolved topologies at low edge density levels. The way in which molecular similarity relationships are assessed is an important determinant of CSN topology. Previous CSN versions were based on numerical similarity functions or the assessment of substructure-based similarity. Herein, we report a new CSN design that is based upon combined numerical and substructure similarity evaluation. This has been facilitated by calculating numerical similarity values on the basis of maximum common substructures (MCSs) of compounds, leading to the introduction of MCS-based CSNs (MCS-CSNs). This CSN design combines advantages of continuous numerical similarity functions with a robust and chemically intuitive substructure-based assessment. Compared to earlier version of CSNs, MCS-CSNs are characterized by a further improved organization of local compound communities as exemplified by the delineation of drug-like subspaces in regions of biologically relevant chemical space.

  12. University-Preschool Partnership and Workplace-Based Learning: A Collaborative "Third Space" or No Space at All?

    Science.gov (United States)

    Jónsdóttir, Arna H.

    2015-01-01

    The article examines the aims of the workplace-based learning of prospective preschool teachers in Iceland and associated cooperative practices between the University of Iceland and preschools. A "third space" of collaboration between these two sites is considered necessary if the education of preschool student teachers is to be…

  13. Characterizing the Trade Space Between Capability and Complexity in Next Generation Cloud and Precipitation Observing Systems Using Markov Chain Monte Carlos Techniques

    Science.gov (United States)

    Xu, Z.; Mace, G. G.; Posselt, D. J.

    2017-12-01

    As we begin to contemplate the next generation atmospheric observing systems, it will be critically important that we are able to make informed decisions regarding the trade space between scientific capability and the need to keep complexity and cost within definable limits. To explore this trade space as it pertains to understanding key cloud and precipitation processes, we are developing a Markov Chain Monte Carlo (MCMC) algorithm suite that allows us to arbitrarily define the specifications of candidate observing systems and then explore how the uncertainties in key retrieved geophysical parameters respond to that observing system. MCMC algorithms produce a more complete posterior solution space, and allow for an objective examination of information contained in measurements. In our initial implementation, MCMC experiments are performed to retrieve vertical profiles of cloud and precipitation properties from a spectrum of active and passive measurements collected by aircraft during the ACE Radiation Definition Experiments (RADEX). Focusing on shallow cumulus clouds observed during the Integrated Precipitation and Hydrology EXperiment (IPHEX), observing systems in this study we consider W and Ka-band radar reflectivity, path-integrated attenuation at those frequencies, 31 and 94 GHz brightness temperatures as well as visible and near-infrared reflectance. By varying the sensitivity and uncertainty of these measurements, we quantify the capacity of various combinations of observations to characterize the physical properties of clouds and precipitation.

  14. Functional observer and state feedback

    International Nuclear Information System (INIS)

    Zhang, S.Y.

    1986-01-01

    In this paper, we show the relation between state space approach and transfer function approach for functional observer and state feedback design. Two approaches can be transformed into each other, based on this result. More importantly, we find that the state space approach introduces some severe, unnecessary restrictions in solving the problem. The restrictions are, however, reduced to be a trivial condition in transfer function approach. It is believed that the result presented in this paper will be useful in developing both approaches, and motivate some new results for solving the problem

  15. Laser interferometry for the Big Bang Observer

    OpenAIRE

    Harry, Gregory M.; Fritschel, Peter; Shaddock, Daniel A.; Folkner, William; Phinney, E. Sterl

    2006-01-01

    The Big Bang Observer is a proposed space-based gravitational-wave detector intended as a follow on mission to the Laser Interferometer Space Antenna (LISA). It is designed to detect the stochastic background of gravitational waves from the early universe. We discuss how the interferometry can be arranged between three spacecraft for this mission and what research and development on key technologies are necessary to realize this scheme.

  16. Laser interferometry for the Big Bang Observer

    Energy Technology Data Exchange (ETDEWEB)

    Harry, Gregory M [LIGO Laboratory, Massachusetts Institute of Technology, NW17-161, Cambridge, MA 02139 (United States); Fritschel, Peter [LIGO Laboratory, Massachusetts Institute of Technology, NW17-161, Cambridge, MA 02139 (United States); Shaddock, Daniel A [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Folkner, William [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Phinney, E Sterl [California Institute of Technology, Pasadena, CA 91125 (United States)

    2006-08-07

    The Big Bang Observer is a proposed space-based gravitational-wave detector intended as a follow on mission to the Laser Interferometer Space Antenna (LISA). It is designed to detect the stochastic background of gravitational waves from the early universe. We discuss how the interferometry can be arranged between three spacecraft for this mission and what research and development on key technologies are necessary to realize this scheme.

  17. Space situational awareness satellites and ground based radiation counting and imaging detector technology

    International Nuclear Information System (INIS)

    Jansen, Frank; Behrens, Joerg; Pospisil, Stanislav; Kudela, Karel

    2011-01-01

    We review the current status from the scientific and technological point of view of solar energetic particles, solar and galactic cosmic ray measurements as well as high energy UV-, X- and gamma-ray imaging of the Sun. These particles and electromagnetic data are an important tool for space situational awareness (SSA) aspects like space weather storm predictions to avoid failures in space, air and ground based technological systems. Real time data acquisition, position and energy sensitive imaging are demanded by the international space weather forecast services. We present how newly developed, highly miniaturized radiation detectors can find application in space in view of future SSA related satellites as a novel space application due to their counting and imaging capabilities.

  18. Space situational awareness satellites and ground based radiation counting and imaging detector technology

    Energy Technology Data Exchange (ETDEWEB)

    Jansen, Frank, E-mail: frank.jansen@dlr.de [DLR Institute of Space Systems, Robert-Hooke-Str. 7, 28359 Bremen (Germany); Behrens, Joerg [DLR Institute of Space Systems, Robert-Hooke-Str. 7, 28359 Bremen (Germany); Pospisil, Stanislav [Czech Technical University, IEAP, 12800 Prague 2, Horska 3a/22 (Czech Republic); Kudela, Karel [Slovak Academy of Sciences, IEP, 04001 Kosice, Watsonova 47 (Slovakia)

    2011-05-15

    We review the current status from the scientific and technological point of view of solar energetic particles, solar and galactic cosmic ray measurements as well as high energy UV-, X- and gamma-ray imaging of the Sun. These particles and electromagnetic data are an important tool for space situational awareness (SSA) aspects like space weather storm predictions to avoid failures in space, air and ground based technological systems. Real time data acquisition, position and energy sensitive imaging are demanded by the international space weather forecast services. We present how newly developed, highly miniaturized radiation detectors can find application in space in view of future SSA related satellites as a novel space application due to their counting and imaging capabilities.

  19. Laboratory simulation of space plasma phenomena*

    Science.gov (United States)

    Amatucci, B.; Tejero, E. M.; Ganguli, G.; Blackwell, D.; Enloe, C. L.; Gillman, E.; Walker, D.; Gatling, G.

    2017-12-01

    Laboratory devices, such as the Naval Research Laboratory's Space Physics Simulation Chamber, are large-scale experiments dedicated to the creation of large-volume plasmas with parameters realistically scaled to those found in various regions of the near-Earth space plasma environment. Such devices make valuable contributions to the understanding of space plasmas by investigating phenomena under carefully controlled, reproducible conditions, allowing for the validation of theoretical models being applied to space data. By working in collaboration with in situ experimentalists to create realistic conditions scaled to those found during the observations of interest, the microphysics responsible for the observed events can be investigated in detail not possible in space. To date, numerous investigations of phenomena such as plasma waves, wave-particle interactions, and particle energization have been successfully performed in the laboratory. In addition to investigations such as plasma wave and instability studies, the laboratory devices can also make valuable contributions to the development and testing of space plasma diagnostics. One example is the plasma impedance probe developed at NRL. Originally developed as a laboratory diagnostic, the sensor has now been flown on a sounding rocket, is included on a CubeSat experiment, and will be included on the DoD Space Test Program's STP-H6 experiment on the International Space Station. In this presentation, we will describe several examples of the laboratory investigation of space plasma waves and instabilities and diagnostic development. *This work supported by the NRL Base Program.

  20. Space debris: modeling and detectability

    Science.gov (United States)

    Wiedemann, C.; Lorenz, J.; Radtke, J.; Kebschull, C.; Horstmann, A.; Stoll, E.

    2017-01-01

    High precision orbit determination is required for the detection and removal of space debris. Knowledge of the distribution of debris objects in orbit is necessary for orbit determination by active or passive sensors. The results can be used to investigate the orbits on which objects of a certain size at a certain frequency can be found. The knowledge of the orbital distribution of the objects as well as their properties in accordance with sensor performance models provide the basis for estimating the expected detection rates. Comprehensive modeling of the space debris environment is required for this. This paper provides an overview of the current state of knowledge about the space debris environment. In particular non-cataloged small objects are evaluated. Furthermore, improvements concerning the update of the current space debris model are addressed. The model of the space debris environment is based on the simulation of historical events, such as fragmentations due to explosions and collisions that actually occurred in Earth orbits. The orbital distribution of debris is simulated by propagating the orbits considering all perturbing forces up to a reference epoch. The modeled object population is compared with measured data and validated. The model provides a statistical distribution of space objects, according to their size and number. This distribution is based on the correct consideration of orbital mechanics. This allows for a realistic description of the space debris environment. Subsequently, a realistic prediction can be provided concerning the question, how many pieces of debris can be expected on certain orbits. To validate the model, a software tool has been developed which allows the simulation of the observation behavior of ground-based or space-based sensors. Thus, it is possible to compare the results of published measurement data with simulated detections. This tool can also be used for the simulation of sensor measurement campaigns. It is

  1. Dual spaces of local Morrey-type spaces

    OpenAIRE

    Gogatishvili, A. (Amiran); Mustafayev, R. (Rza)

    2011-01-01

    In this paper we show that associated spaces and dual spaces of the local Morrey-type spaces are so called complementary local Morrey-type spaces. Our method is based on an application of multidimensional reverse Hardy inequalities.

  2. A Danish Perspective on Problem Based Learning in Space Education

    DEFF Research Database (Denmark)

    Bhanderi, Dan D. V.; Bisgaard, Morten; Alminde, Lars

    2006-01-01

    This paper describes the goals of the Student Satellite Program at Aalborg University (AAU), and the means for implementing it, namely a concept called Problem Based Learning, which is the cornerstone in the education at AAU. AAU has within the last decade chosen to focus strongly on education...... in space technology, not because the country lacks aerospace engineers, but because space projects require the students to think about systems rather than individual modules, while providing problems that are technically challenging for the students to solve. This combination makes the graduates very...

  3. VIP: A knowledge-based design aid for the engineering of space systems

    Science.gov (United States)

    Lewis, Steven M.; Bellman, Kirstie L.

    1990-01-01

    The Vehicles Implementation Project (VIP), a knowledge-based design aid for the engineering of space systems is described. VIP combines qualitative knowledge in the form of rules, quantitative knowledge in the form of equations, and other mathematical modeling tools. The system allows users rapidly to develop and experiment with models of spacecraft system designs. As information becomes available to the system, appropriate equations are solved symbolically and the results are displayed. Users may browse through the system, observing dependencies and the effects of altering specific parameters. The system can also suggest approaches to the derivation of specific parameter values. In addition to providing a tool for the development of specific designs, VIP aims at increasing the user's understanding of the design process. Users may rapidly examine the sensitivity of a given parameter to others in the system and perform tradeoffs or optimizations of specific parameters. A second major goal of VIP is to integrate the existing corporate knowledge base of models and rules into a central, symbolic form.

  4. James Webb Space Telescope Observations of Stellar Occultations by Solar System Bodies and Rings

    Science.gov (United States)

    Santos-Sanz, P.; French, R. G.; Pinilla-Alonso, N.; Stansberry, J.; Lin, Z-Y.; Zhang, Z-W.; Vilenius, E.; Mueller, Th.; Ortiz, J. L.; Braga-Ribas, F.; hide

    2016-01-01

    In this paper, we investigate the opportunities provided by the James Webb Space Telescope (JWST) for significant scientific advances in the study of Solar System bodies and rings using stellar occultations. The strengths and weaknesses of the stellar occultation technique are evaluated in light of JWST's unique capabilities. We identify several possible JWST occultation events by minor bodies and rings and evaluate their potential scientific value. These predictions depend critically on accurate a priori knowledge of the orbit of JWST near the Sun–Earth Lagrange point 2 (L2). We also explore the possibility of serendipitous stellar occultations by very small minor bodies as a byproduct of other JWST observing programs. Finally, to optimize the potential scientific return of stellar occultation observations, we identify several characteristics of JWST's orbit and instrumentation that should be taken into account during JWST's development.

  5. The future of Earth observation in hydrology

    KAUST Repository

    McCabe, Matthew; Rodell, Matthew; Alsdorf, Douglas E.; Miralles, Diego G.; Uijlenhoet, Remko; Wagner, Wolfgang; Lucieer, Arko; Houborg, Rasmus; Verhoest, Niko E. C.; Franz, Trenton E.; Shi, Jiancheng; Gao, Huilin; Wood, Eric F.

    2017-01-01

    In just the past 5 years, the field of Earth observation has progressed beyond the offerings of conventional space-agency-based platforms to include a plethora of sensing opportunities afforded by CubeSats, unmanned aerial vehicles

  6. BASE-A space experiment with Rhodospirillum rubrum S1H

    Data.gov (United States)

    National Aeronautics and Space Administration — R. rubrum S1H inoculated on solid minimal media was sent to the ISS in September 2006 (BASE-A experiment). After 10 days flight R. rubrum cultures returned back to...

  7. Relative-locality distant observers and the phenomenology of momentum-space geometry

    International Nuclear Information System (INIS)

    Amelino-Camelia, Giovanni; Rosati, Giacomo; Trevisan, Gabriele; Arzano, Michele; Kowalski-Glikman, Jerzy

    2012-01-01

    We study the translational invariance of the relative-locality framework proposed in Amelino-Camelia et al (2011 Phys. Rev. D 84 084010), which had been previously established only for the case of a single interaction. We provide an explicit example of boundary conditions at endpoints of worldlines, which indeed ensures the desired translational invariance for processes involving several interactions, even when some of the interactions are causally connected (particle exchange). We illustrate the properties of the associated relativistic description of distant observers within the example of a κ-Poincare-inspired momentum-space geometry, with de Sitter metric and parallel transport governed by a non-metric and torsionful connection. We find that in such a theory, simultaneously emitted massless particles do not reach simultaneously a distant detector, as expected in light of the findings of Freidel and Smolin (2011 arXiv:1103.5626) on the implications of non-metric connections. We also show that the theory admits a free-particle limit, where the relative-locality results of Amelino-Camelia et al (2011 Phys. Lett. B 700 150) are reproduced. We establish that the torsion of the κ-Poincare connection introduces a small (but observably large) dependence of the time of detection, for simultaneously emitted particles, on some properties of the interactions producing the particles at the source. (paper)

  8. Relative-locality distant observers and the phenomenology of momentum-space geometry

    Science.gov (United States)

    Amelino-Camelia, Giovanni; Arzano, Michele; Kowalski-Glikman, Jerzy; Rosati, Giacomo; Trevisan, Gabriele

    2012-04-01

    We study the translational invariance of the relative-locality framework proposed in Amelino-Camelia et al (2011 Phys. Rev. D 84 084010), which had been previously established only for the case of a single interaction. We provide an explicit example of boundary conditions at endpoints of worldlines, which indeed ensures the desired translational invariance for processes involving several interactions, even when some of the interactions are causally connected (particle exchange). We illustrate the properties of the associated relativistic description of distant observers within the example of a κ-Poincaré-inspired momentum-space geometry, with de Sitter metric and parallel transport governed by a non-metric and torsionful connection. We find that in such a theory, simultaneously emitted massless particles do not reach simultaneously a distant detector, as expected in light of the findings of Freidel and Smolin (2011 arXiv:1103.5626) on the implications of non-metric connections. We also show that the theory admits a free-particle limit, where the relative-locality results of Amelino-Camelia et al (2011 Phys. Lett. B 700 150) are reproduced. We establish that the torsion of the κ-Poincaré connection introduces a small (but observably large) dependence of the time of detection, for simultaneously emitted particles, on some properties of the interactions producing the particles at the source.

  9. Environment monitoring from space

    International Nuclear Information System (INIS)

    Takagi, M.

    1994-01-01

    Environmental problems such as acid rain, ozone depletion, deforestation, erosion, and the greenhouse effect are of increasing concern, and continuous earth observation from artificial satellites has been contributing significant information on the environment since the 1960s. Earth observation from space has the advantages of wide area coverage at potentially high resolutions, periodic and long-term observation capability, data acquisition with uniform quality and repeatability, and ability to observe using different types of sensors. Problems to be solved in earth observation include the need for preprocessing of satellite data, understanding the relationship between observed physical parameters and objects, and the high volume of data for processing. In Japan, a research project on the higher-order utilization of remote sensing data from space was organized in 1985, and the results led to recognition of the importance of satellite observation. It was then decided to undertake a program to improve the understanding of the earth environment by satellite. Five research plans were selected: a basic study on earth observation by microwaves; global change analysis of the biosphere; a study of the physical process of the water cycle over land; a study of air-sea interaction; and higher-order processing of earth observation information. In recognition of the international nature of satellite data, as well as the capabilities of Canada and Japan in computer, communication, and multimedia technologies, bilateral cooperation is proposed in the area of earth environment information systems based on satellite observation

  10. SOLAR-ISS: A new reference spectrum based on SOLAR/SOLSPEC observations

    Science.gov (United States)

    Meftah, M.; Damé, L.; Bolsée, D.; Hauchecorne, A.; Pereira, N.; Sluse, D.; Cessateur, G.; Irbah, A.; Bureau, J.; Weber, M.; Bramstedt, K.; Hilbig, T.; Thiéblemont, R.; Marchand, M.; Lefèvre, F.; Sarkissian, A.; Bekki, S.

    2018-03-01

    Context. Since April 5, 2008 and up to February 15, 2017, the SOLar SPECtrometer (SOLSPEC) instrument of the SOLAR payload on board the International Space Station (ISS) has performed accurate measurements of solar spectral irradiance (SSI) from the middle ultraviolet to the infrared (165 to 3088 nm). These measurements are of primary importance for a better understanding of solar physics and the impact of solar variability on climate. In particular, a new reference solar spectrum (SOLAR-ISS) is established in April 2008 during the solar minima of cycles 23-24 thanks to revised engineering corrections, improved calibrations, and advanced procedures to account for thermal and aging corrections of the SOLAR/SOLSPEC instrument. Aims: The main objective of this article is to present a new high-resolution solar spectrum with a mean absolute uncertainty of 1.26% at 1σ from 165 to 3000 nm. This solar spectrum is based on solar observations of the SOLAR/SOLSPEC space-based instrument. Methods: The SOLAR/SOLSPEC instrument consists of three separate double monochromators that use concave holographic gratings to cover the middle ultraviolet (UV), visible (VIS), and infrared (IR) domains. Our best ultraviolet, visible, and infrared spectra are merged into a single absolute solar spectrum covering the 165-3000 nm domain. The resulting solar spectrum has a spectral resolution varying between 0.6 and 9.5 nm in the 165-3000 nm wavelength range. We build a new solar reference spectrum (SOLAR-ISS) by constraining existing high-resolution spectra to SOLAR/SOLSPEC observed spectrum. For that purpose, we account for the difference of resolution between the two spectra using the SOLAR/SOLSPEC instrumental slit functions. Results: Using SOLAR/SOLSPEC data, a new solar spectrum covering the 165-3000 nm wavelength range is built and is representative of the 2008 solar minimum. It has a resolution better than 0.1 nm below 1000 nm and 1 nm in the 1000-3000 nm wavelength range. The new

  11. Observational modeling of topological spaces

    International Nuclear Information System (INIS)

    Molaei, M.R.

    2009-01-01

    In this paper a model for a multi-dimensional observer by using of the fuzzy theory is presented. Relative form of Tychonoff theorem is proved. The notion of topological entropy is extended. The persistence of relative topological entropy under relative conjugate relation is proved.

  12. Atomic oxygen effects on boron nitride and silicon nitride: A comparison of ground based and space flight data

    Science.gov (United States)

    Cross, J. B.; Lan, E. H.; Smith, C. A.; Whatley, W. J.

    1990-01-01

    The effects of atomic oxygen on boron nitride (BN) and silicon nitride (Si3N4) were evaluated in a low Earth orbit (LEO) flight experiment and in a ground based simulation facility. In both the inflight and ground based experiments, these materials were coated on thin (approx. 250A) silver films, and the electrical resistance of the silver was measured in situ to detect any penetration of atomic oxygen through the BN and Si3N4 materials. In the presence of atomic oxygen, silver oxidizes to form silver oxide, which has a much higher electrical resistance than pure silver. Permeation of atomic oxygen through BN, as indicated by an increase in the electrical resistance of the silver underneath, was observed in both the inflight and ground based experiments. In contrast, no permeation of atomic oxygen through Si3N4 was observed in either the inflight or ground based experiments. The ground based results show good qualitative correlation with the LEO flight results, indicating that ground based facilities such as the one at Los Alamos National Lab can reproduce space flight data from LEO.

  13. Effectiveness of media awareness campaigns on the proportion of vehicles that give space to ambulances on roads: An observational study.

    Science.gov (United States)

    Shaikh, Shiraz; Baig, Lubna A; Polkowski, Maciej

    2017-01-01

    The findings of the Health Care in Danger project in Karachi suggests that there is presence of behavioral negligence among vehicle operators on roads in regards to giving way to ambulances. A mass media campaign was conducted to raise people's awareness on the importance of giving way to ambulances. The main objective of this study was to determine the effectiveness of the campaign on increasing the proportion of vehicles that give way to ambulances. This was a quasi-experimental study that was based on before and after design. Three observation surveys were carried out in different areas of the city in Karachi, Pakistan before, during and after the campaign by trained observers who recorded their findings on a checklist. Each observation was carried out at three different times of the day for at least two days on each road. The relationship of the media campaign with regards to a vehicle giving space to an ambulance was calculated by means of odds ratios and 95% confidence intervals using multivariate logistic regression. Overall, 245 observations were included in the analysis. Traffic congestion and negligence/resistance, by vehicles operators who were in front of the ambulance, were the two main reasons why ambulances were not given way. Other reasons include: sudden stops by minibuses and in the process causing obstruction, ambulances not rushing through to alert vehicle operators to give way and traffic interruption by VIP movement. After adjustment for site, time of day, type of ambulance and number of cars in front of the ambulance, vehicles during (OR=2.13, 95% CI=1.22-3.71, p=0.007) and after the campaign (OR=1.73, 95% CI=1.02-2.95, p=0.042) were significantly more likely give space to ambulances. Mass media campaigns can play a significant role in changing the negligent behavior of people, especially when the campaign conveys a humanitarian message such as: giving way to ambulances can save lives.

  14. Research on Control Method Based on Real-Time Operational Reliability Evaluation for Space Manipulator

    Directory of Open Access Journals (Sweden)

    Yifan Wang

    2014-05-01

    Full Text Available A control method based on real-time operational reliability evaluation for space manipulator is presented for improving the success rate of a manipulator during the execution of a task. In this paper, a method for quantitative analysis of operational reliability is given when manipulator is executing a specified task; then a control model which could control the quantitative operational reliability is built. First, the control process is described by using a state space equation. Second, process parameters are estimated in real time using Bayesian method. Third, the expression of the system's real-time operational reliability is deduced based on the state space equation and process parameters which are estimated using Bayesian method. Finally, a control variable regulation strategy which considers the cost of control is given based on the Theory of Statistical Process Control. It is shown via simulations that this method effectively improves the operational reliability of space manipulator control system.

  15. A modular Space Station/Base electrical power system - Requirements and design study.

    Science.gov (United States)

    Eliason, J. T.; Adkisson, W. B.

    1972-01-01

    The requirements and procedures necessary for definition and specification of an electrical power system (EPS) for the future space station are discussed herein. The considered space station EPS consists of a replaceable main power module with self-contained auxiliary power, guidance, control, and communication subsystems. This independent power source may 'plug into' a space station module which has its own electrical distribution, control, power conditioning, and auxiliary power subsystems. Integration problems are discussed, and a transmission system selected with local floor-by-floor power conditioning and distribution in the station module. This technique eliminates the need for an immediate long range decision on the ultimate space base power sources by providing capability for almost any currently considered option.

  16. Skylab experiments. Volume 5: Astronomy and space physics. [Skylab observations of galactic radiation, solar energy, and interplanetary composition for high school level education

    Science.gov (United States)

    1973-01-01

    The astronomy and space physics investigations conducted in the Skylab program include over 20 experiments in four categories to explore space phenomena that cannot be observed from earth. The categories of space research are as follows: (1) phenomena within the solar system, such as the effect of solar energy on Earth's atmosphere, the composition of interplanetary space, the possibility of an inner planet, and the X-ray radiation from Jupiter, (2) analysis of energetic particles such as cosmic rays and neutrons in the near-earth space, (3) stellar and galactic astronomy, and (4) self-induced environment surrounding the Skylab spacecraft.

  17. An ultra-stable iodine-based frequency reference for space applications

    Science.gov (United States)

    Schuldt, Thilo; Braxmaier, Claus; Doeringshoff, Klaus; Keetman, Anja; Reggentin, Matthias; Kovalchuk, Evgeny; Peters, Achim

    2012-07-01

    Future space missions require for ultra-stable optical frequency references. Examples are the gravitational wave detector LISA/eLISA (Laser Interferometer Space Antenna), the SpaceTime Asymmetry Research (STAR) program, the aperture-synthesis telescope Darwin and the GRACE (Gravity Recovery and Climate Experiment) follow on mission exploring Earth's gravity. As high long-term frequency stability is required, lasers stabilized to atomic or molecular transitions are preferred, also offering an absolute frequency reference. Frequency stabilities in the 10 ^{-15} domains at longer integration times (up to several hours) are demonstrated in laboratory experiments using setups based on Doppler-free spectroscopy. Such setups with a frequency stability comparable to the hydrogen maser in the microwave domain, have the potential to be developed space compatible on a relatively short time scale. Here, we present the development of ultra-stable optical frequency references based on modulation-transfer spectroscopy of molecular iodine. Noise levels of 2\\cdot10 ^{-14} at an integration time of 1 s and below 3\\cdot10 ^{-15} at integration times between 100 s and 1000 s are demonstrated with a laboratory setup using an 80 cm long iodine cell in single-pass configuration in combination with a frequency-doubled Nd:YAG laser and standard optical components and optomechanic mounts. The frequency stability at longer integration times is (amongst other things) limited by the dimensional stability of the optical setup, i.e. by th pointing stability of the two counter-propagating beams overlapped in the iodine cell. With the goal of a future space compatible setup, a compact frequency standard on EBB (elegant breadboard) level was realized. The spectroscopy unit utilizes a baseplate made of Clearceram-HS, a glass ceramics with an ultra-low coefficient of thermal expansion of 2\\cdot10 ^{-8} K ^{-1}. The optical components are joint to the baseplate using adhesive bonding technology

  18. Results of the Simulation and Assimilation of Doppler Wind Lidar Observations in Preparation for European Space Agency's Aeolus Mission

    Science.gov (United States)

    McCarty, Will

    2011-01-01

    With the launch of the European Space Agency's Aeolus Mission in 2013, direct spaceborne measurements of vertical wind profiles are imminent via Doppler wind lidar technology. Part of the preparedness for such missions is the development of the proper data assimilation methodology for handling such observations. Since no heritage measurements exist in space, the Joint Observing System Simulation Experiment (Joint OSSE) framework has been utilized to generate a realistic proxy dataset as a precursor to flight. These data are being used for the development of the Gridpoint Statistical Interpolation (GSI) data assimilation system utilized at a number of centers through the United States including the Global Modeling and Assimilation Office (GMAO) at NASA/Goddard Space Flight Center and at the National Centers for Environmental Prediction (NOAA/NWS/NCEP) as an activity through the Joint Center for Satellite Data Assimilation. An update of this ongoing effort will be presented, including the methodology of proxy data generation, the limitations of the proxy data, the handling of line-of-sight wind measurements within the GSI, and the impact on both analyses and forecasts with the addition of the new data type.

  19. Rocket-Based Combined Cycle Activities in the Advanced Space Transportation Program Office

    Science.gov (United States)

    Hueter, Uwe; Turner, James

    1999-01-01

    NASA's Office of Aero-Space Technology (OAST) has established three major goals, referred to as, "The Three Pillars for Success". The Advanced Space Transportation Program Office (ASTP) at the NASA's Marshall Space Flight Center (MSFC) in Huntsville, Ala. focuses on future space transportation technologies Under the "Access to Space" pillar. The Core Technologies Project, part of ASTP, focuses on the reusable technologies beyond those being pursued by X-33. One of the main activities over the past two and a half years has been on advancing the rocket-based combined cycle (RBCC) technologies. In June of last year, activities for reusable launch vehicle (RLV) airframe and propulsion technologies were initiated. These activities focus primarily on those technologies that support the decision to determine the path this country will take for Space Shuttle and RLV. This year, additional technology efforts in the reusable technologies will be awarded. The RBCC effort that was completed early this year was the initial step leading to flight demonstrations of the technology for space launch vehicle propulsion.

  20. The James Webb Space Telescope's Plan for Operations and Instrument Capabilities for Observations in the Solar System

    Science.gov (United States)

    Milam, Stefanie N.; Stansberry, John A.; Sonneborn, George; Thomas, Cristina

    2016-01-01

    The James Webb Space Telescope (JWST) is optimized for observations in the near- and mid-infrared and will provide essential observations for targets that cannot be conducted from the ground or other missions during its lifetime. The state-of-the-art science instruments, along with the telescope's moving target tracking, will enable the infrared study, with unprecedented detail, for nearly every object (Mars and beyond) in the Solar System. The goals of this special issue are to stimulate discussion and encourage participation in JWST planning among members of the planetary science community. Key science goals for various targets, observing capabilities for JWST, and highlights for the complementary nature with other missions/observatories are described in this paper.

  1. Recharge signal identification based on groundwater level observations.

    Science.gov (United States)

    Yu, Hwa-Lung; Chu, Hone-Jay

    2012-10-01

    This study applied a method of the rotated empirical orthogonal functions to directly decompose the space-time groundwater level variations and determine the potential recharge zones by investigating the correlation between the identified groundwater signals and the observed local rainfall records. The approach is used to analyze the spatiotemporal process of piezometric heads estimated by Bayesian maximum entropy method from monthly observations of 45 wells in 1999-2007 located in the Pingtung Plain of Taiwan. From the results, the primary potential recharge area is located at the proximal fan areas where the recharge process accounts for 88% of the spatiotemporal variations of piezometric heads in the study area. The decomposition of groundwater levels associated with rainfall can provide information on the recharge process since rainfall is an important contributor to groundwater recharge in semi-arid regions. Correlation analysis shows that the identified recharge closely associates with the temporal variation of the local precipitation with a delay of 1-2 months in the study area.

  2. New interpretation of matter-antimatter asymmetry based on branes and possible observational consequences

    International Nuclear Information System (INIS)

    Cai Ronggen; Li Tong; Li Xueqian; Wang Xun

    2007-01-01

    Motivated by the alpha-magnetic-spectrometer (AMS) project, we assume that after the big bang or inflation epoch, antimatter was repelled onto one brane which is separated from our brane where all the observational matter resides. It is suggested that CP may be spontaneously broken, the two branes would correspond to ground states for matter and antimatter, respectively. Generally a complex scalar field which is responsible for the spontaneous CP violation, exists in the space between the branes. The matter and antimatter on the two branes attract each other via gravitational force, meanwhile the scalar field causes a Casimir effect to result in a repulsive force against the gravitation. We find that the Casimir force is much stronger than the gravitational force, as long as the separation of the two branes is small. Thus at early epoch after the big bang, the two branes were closer and then have been separated by the Casimir repulsive force from each other. The trend will continue until the separation is sufficiently large and then the gravitational force observed in our four-space would obviously deviate from the Newton's universal gravitational law. We suppose that there is a potential barrier at the brane boundary, which is similar to the surface tension for a water membrane. The barrier prevents the matter (antimatter) particles from entering the space between two branes and jump from one brane to another. However, by the quantum tunneling, a sizable antimatter flux may come to our brane and be observed by the AMS. In this work by considering two possible models, i.e. the naive flat space-time and Randall-Sundrum models, and using the observational data on the visible matter in our universe as inputs, we derive the antimatter flux which comes to our detector in the nonrelativistic approximation and make a rough numerical estimate of possible numbers of antihelium at AMS

  3. SpacePy - a Python-based library of tools for the space sciences

    International Nuclear Information System (INIS)

    Morley, Steven K.; Welling, Daniel T.; Koller, Josef; Larsen, Brian A.; Henderson, Michael G.

    2010-01-01

    Space science deals with the bodies within the solar system and the interplanetary medium; the primary focus is on atmospheres and above - at Earth the short timescale variation in the the geomagnetic field, the Van Allen radiation belts and the deposition of energy into the upper atmosphere are key areas of investigation. SpacePy is a package for Python, targeted at the space sciences, that aims to make basic data analysis, modeling and visualization easier. It builds on the capabilities of the well-known NumPy and MatPlotLib packages. Publication quality output direct from analyses is emphasized. The SpacePy project seeks to promote accurate and open research standards by providing an open environment for code development. In the space physics community there has long been a significant reliance on proprietary languages that restrict free transfer of data and reproducibility of results. By providing a comprehensive, open-source library of widely used analysis and visualization tools in a free, modern and intuitive language, we hope that this reliance will be diminished. SpacePy includes implementations of widely used empirical models, statistical techniques used frequently in space science (e.g. superposed epoch analysis), and interfaces to advanced tools such as electron drift shell calculations for radiation belt studies. SpacePy also provides analysis and visualization tools for components of the Space Weather Modeling Framework - currently this only includes the BATS-R-US 3-D magnetohydrodynamic model and the RAM ring current model - including streamline tracing in vector fields. Further development is currently underway. External libraries, which include well-known magnetic field models, high-precision time conversions and coordinate transformations are wrapped for access from Python using SWIG and f2py. The rest of the tools have been implemented directly in Python. The provision of open-source tools to perform common tasks will provide openness in the

  4. Space-Based Reconfigurable Software Defined Radio Test Bed Aboard International Space Station

    Science.gov (United States)

    Reinhart, Richard C.; Lux, James P.

    2014-01-01

    The National Aeronautical and Space Administration (NASA) recently launched a new software defined radio research test bed to the International Space Station. The test bed, sponsored by the Space Communications and Navigation (SCaN) Office within NASA is referred to as the SCaN Testbed. The SCaN Testbed is a highly capable communications system, composed of three software defined radios, integrated into a flight system, and mounted to the truss of the International Space Station. Software defined radios offer the future promise of in-flight reconfigurability, autonomy, and eventually cognitive operation. The adoption of software defined radios offers space missions a new way to develop and operate space transceivers for communications and navigation. Reconfigurable or software defined radios with communications and navigation functions implemented in software or VHDL (Very High Speed Hardware Description Language) provide the capability to change the functionality of the radio during development or after launch. The ability to change the operating characteristics of a radio through software once deployed to space offers the flexibility to adapt to new science opportunities, recover from anomalies within the science payload or communication system, and potentially reduce development cost and risk by adapting generic space platforms to meet specific mission requirements. The software defined radios on the SCaN Testbed are each compliant to NASA's Space Telecommunications Radio System (STRS) Architecture. The STRS Architecture is an open, non-proprietary architecture that defines interfaces for the connections between radio components. It provides an operating environment to abstract the communication waveform application from the underlying platform specific hardware such as digital-to-analog converters, analog-to-digital converters, oscillators, RF attenuators, automatic gain control circuits, FPGAs, general-purpose processors, etc. and the interconnections among

  5. Operation of commercially-based microcomputer technology in a space radiation environment

    Science.gov (United States)

    Yelverton, J. N.

    This paper focuses on detection and recovery techniques that should enable the reliable operation of commercially-based microprocessor technology in the harsh radiation environment of space and at high altitudes. This approach is especially significant in light of the current shift in emphasis (due to cost) from space hardened Class-S parts qualification to a more direct use of commercial parts. The method should offset some of the concern that the newer high density state-of-the-art RISC and CISC microprocessors can be used in future space applications. Also, commercial aviation, should benefit, since radiation induced transients are a new issue arising from the increased quantities of microcomputers used in aircraft avionics.

  6. Exploration Space Suit Architecture and Destination Environmental-Based Technology Development

    Science.gov (United States)

    Hill, Terry R.; McFarland, Shane M.; Korona, F. Adam

    2013-01-01

    This paper continues forward where EVA Space Suit Architecture: Low Earth Orbit Vs. Moon Vs. Mars left off in the development of a space suit architecture that is modular in design and could be reconfigured prior to launch or during any given mission depending on the tasks or destination. This space suit system architecture and technologies required based on human exploration (EVA) destinations will be discussed, and how these systems should evolve to meet the future exploration EVA needs of the US human space flight program. A series of exercises and analyses provided a strong indication that the Constellation Program space suit architecture, with its maximum reuse of technology and functionality across a range of mission profiles and destinations, is postured to provide a viable solution for future space exploration missions. The destination environmental analysis demonstrates that the modular architecture approach could provide the lowest mass and mission cost for the protection of the crew, given any human mission outside of low-Earth orbit. Additionally, some of the high-level trades presented here provide a review of the environmental and nonenvironmental design drivers that will become increasingly important as humans venture farther from Earth. The presentation of destination environmental data demonstrates a logical clustering of destination design environments that allows a focused approach to technology prioritization, development, and design that will maximize the return on investment, largely independent of any particular design reference mission.

  7. Leucine-based receptor sorting motifs are dependent on the spacing relative to the plasma membrane

    DEFF Research Database (Denmark)

    Geisler, C; Dietrich, J; Nielsen, B L

    1998-01-01

    Many integral membrane proteins contain leucine-based motifs within their cytoplasmic domains that mediate internalization and intracellular sorting. Two types of leucine-based motifs have been identified. One type is dependent on phosphorylation, whereas the other type, which includes an acidic...... amino acid, is constitutively active. In this study, we have investigated how the spacing relative to the plasma membrane affects the function of both types of leucine-based motifs. For phosphorylation-dependent leucine-based motifs, a minimal spacing of 7 residues between the plasma membrane...... and the phospho-acceptor was required for phosphorylation and thereby activation of the motifs. For constitutively active leucine-based motifs, a minimal spacing of 6 residues between the plasma membrane and the acidic residue was required for optimal activity of the motifs. In addition, we found that the acidic...

  8. An optimum organizational structure for a large earth-orbiting multidisciplinary Space Base

    Science.gov (United States)

    Ragusa, J. M.

    1973-01-01

    The purpose of this exploratory study was to identify an optimum hypothetical organizational structure for a large earth-orbiting multidisciplinary research and applications (R&A) Space Base manned by a mixed crew of technologists. Since such a facility does not presently exist, in situ empirical testing was not possible. Study activity was, therefore, concerned with the identification of a desired organizational structural model rather than the empirical testing of it. The essential finding of this research was that a four-level project type 'total matrix' model will optimize the efficiency and effectiveness of Space Base technologists.

  9. Optical asymmetric cryptography using a three-dimensional space-based model

    International Nuclear Information System (INIS)

    Chen, Wen; Chen, Xudong

    2011-01-01

    In this paper, we present optical asymmetric cryptography combined with a three-dimensional (3D) space-based model. An optical multiple-random-phase-mask encoding system is developed in the Fresnel domain, and one random phase-only mask and the plaintext are combined as a series of particles. Subsequently, the series of particles is translated along an axial direction, and is distributed in a 3D space. During image decryption, the robustness and security of the proposed method are further analyzed. Numerical simulation results are presented to show the feasibility and effectiveness of the proposed optical image encryption method

  10. Fuzzy model-based observers for fault detection in CSTR.

    Science.gov (United States)

    Ballesteros-Moncada, Hazael; Herrera-López, Enrique J; Anzurez-Marín, Juan

    2015-11-01

    Under the vast variety of fuzzy model-based observers reported in the literature, what would be the properone to be used for fault detection in a class of chemical reactor? In this study four fuzzy model-based observers for sensor fault detection of a Continuous Stirred Tank Reactor were designed and compared. The designs include (i) a Luenberger fuzzy observer, (ii) a Luenberger fuzzy observer with sliding modes, (iii) a Walcott-Zak fuzzy observer, and (iv) an Utkin fuzzy observer. A negative, an oscillating fault signal, and a bounded random noise signal with a maximum value of ±0.4 were used to evaluate and compare the performance of the fuzzy observers. The Utkin fuzzy observer showed the best performance under the tested conditions. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  11. Internet Technologies for Space-based Communications: State of the Art and Challenges

    Science.gov (United States)

    Bhasin, K.; DePaula, R.; Edwards, C.

    2000-01-01

    The Internet is rapidly changing the ways we communicate information around the globe today. The desire to provide Internet-based services to anyone, anywhere, anytime has brought satellite communications to the forefront to become an integral part of the Internet. In spite of the distances involved, satellite links are proving to be capable of providing Internet services based on Internet protocol (TCP/IP) stack. This development has led to the question particularly at NASA; can satellites and other space platforms become an Internet-node in space? This will allow the direct transfer of information directly from space to the users on Earth and even be able to control the spacecraft and its instruments. NASA even wants to extend the near earth space Internet to deep space applications where scientists and the public here on Earth may view space exploration in real time via the Internet. NASA's future solar system exploration will involve intensive in situ investigations of planets, moons, asteroids, and comets. While past missions typically involved a single fly-by or orbiting science spacecraft, future missions will begin to use fleets of small, highly intelligent robotic vehicles to carry out collaborative investigations. The resulting multi-spacecraft topologies will effectively create a wide area network spanning the solar system. However, this will require significant development in Internet technologies for space use. This paper provides the status'of the Internet for near earth applications and the potential extension of the Internet for use in deep space planetary exploration. The paper will discuss the overall challenges of implementing the space Internet and how the space Internet will integrate into the complex terrestrial systems those forms the Internet of today in a hybrid set of networks. Internet. We envision extending to the deep space environment such Internet concepts as a well-designed layered architecture. This effort will require an ability to

  12. Ultradeep Near-Infrared ISAAC Observations of the Hubble Deep Field South: Observations, Reduction, Multicolor Catalog, and Photometric Redshifts

    Science.gov (United States)

    Labbé, Ivo; Franx, Marijn; Rudnick, Gregory; Schreiber, Natascha M. Förster; Rix, Hans-Walter; Moorwood, Alan; van Dokkum, Pieter G.; van der Werf, Paul; Röttgering, Huub; van Starkenburg, Lottie; van der Wel, Arjen; Kuijken, Konrad; Daddi, Emanuele

    2003-03-01

    We present deep near-infrared (NIR) Js-, H-, and Ks-band ISAAC imaging of the Wide Field Planetary Camera 2 (WFPC2) field of the Hubble Deep Field South (HDF-S). The 2.5‧×2.5‧ high Galactic latitude field was observed with the Very Large Telescope under the best seeing conditions, with integration times amounting to 33.6 hr in Js, 32.3 hr in H, and 35.6 hr in Ks. We reach total AB magnitudes for point sources of 26.8, 26.2, and 26.2, respectively (3 σ), which make it the deepest ground-based NIR observation to date and the deepest Ks-band data in any field. The effective seeing of the co-added images is ~0.45" in Js, ~0.48" in H, and ~0.46" in Ks. Using published WFPC2 optical data, we constructed a Ks-limited multicolor catalog containing 833 sources down to Ktots,AB2.3 (in Johnson magnitudes). Because they are extremely faint in the observed optical, they would be missed by ultraviolet-optical selection techniques, such as the U-dropout method. Based on service mode observations collected at the European Southern Observatory, Paranal, Chile (ESO Program 164.O-0612). Also based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under NASA contract NAS 5-26555.

  13. Birth spacing of pregnant women in Nepal: A community-based study

    Directory of Open Access Journals (Sweden)

    Rajendra Karkee

    2016-09-01

    Full Text Available BackgroundOptimal birth spacing has health advantages for both mother and child. In developing countries, shorter birth intervals are common and associated with social, cultural and economic factors, as well as a lack of family planning. This study investigated the first birth interval after marriage and preceding interbirth interval in Nepal.MethodsA community-based prospective cohort study was conducted in the Kaski district of Nepal. Information on birth spacing, demographic and obstetric characteristics was obtained from 701 pregnant women using a structured questionnaire. Logistic regression analyses were performed to ascertain factors associated with short birth spacing.ResultsAbout 39% of primiparous women gave their first child birth within one year of marriage and 23% of multiparous women had short preceding interbirth intervals (<24 months. The average birth spacing among the multiparous group was 44.9 (SD 21.8 months. Overall, short birth spacing appeared to be inversely associated with advancing maternal age.For the multiparous group, Janajati and lower caste women, and those whose newborn was female, were more likely to have short birth spacing.ConclusionsThe preceding interbirth interval was relatively long in the Kaski district of Nepal and tended to be associated with maternal age, caste, and sex of newborn infant. Optimal birth spacing programs should target Janajati and lower caste women, along with promotion of gender equality in society.

  14. Performance Comparison of Assorted Color Spaces for Multilevel Block Truncation Coding based Face Recognition

    OpenAIRE

    H.B. Kekre; Sudeep Thepade; Karan Dhamejani; Sanchit Khandelwal; Adnan Azmi

    2012-01-01

    The paper presents a performance analysis of Multilevel Block Truncation Coding based Face Recognition among widely used color spaces. In [1], Multilevel Block Truncation Coding was applied on the RGB color space up to four levels for face recognition. Better results were obtained when the proposed technique was implemented using Kekre’s LUV (K’LUV) color space [25]. This was the motivation to test the proposed technique using assorted color spaces. For experimental analysis, two face databas...

  15. Monitoring geospace disturbances through coordinated space-borne and ground-based magnetometer observations

    Science.gov (United States)

    Balasis, Georgios

    2014-05-01

    Recently automated methods of deriving the characteristics of ultra low frequency (ULF) waves in the magnetosphere have been developed (Balasis et al., 2012, 2013), which can be effectively applied to the huge datasets from the new ESA Swarm mission, in order to retrieve, on an operational basis, new information about the near-Earth electromagnetic environment. Processing Swarm measurements with these methods will help to elucidate the processes influencing the generation and propagation of ULF waves, which in turn play a crucial role in magnetospheric dynamics. Moreover, a useful platform based on a combination of wavelet transforms and artificial neural networks has been developed to monitor the wave evolution from the outer boundaries of Earth's magnetosphere through the topside ionosphere down to the surface. Data from a Low Earth Orbit (LEO) satellite (CHAMP) and two magnetospheric missions (Cluster and Geotail) along with three ground-based magnetic networks (CARISMA, GIMA and IMAGE), during the Halloween 2003 magnetic superstorm when the Cluster and CHAMP spacecraft were in good local time (LT) conjunction, are used to demonstrate the potential of the analysis technique in studying wave evolution in detail.

  16. Flare Observations

    Directory of Open Access Journals (Sweden)

    Benz Arnold O.

    2008-02-01

    Full Text Available Solar flares are observed at all wavelengths from decameter radio waves to gamma-rays at 100 MeV. This review focuses on recent observations in EUV, soft and hard X-rays, white light, and radio waves. Space missions such as RHESSI, Yohkoh, TRACE, and SOHO have enlarged widely the observational base. They have revealed a number of surprises: Coronal sources appear before the hard X-ray emission in chromospheric footpoints, major flare acceleration sites appear to be independent of coronal mass ejections (CMEs, electrons, and ions may be accelerated at different sites, there are at least 3 different magnetic topologies, and basic characteristics vary from small to large flares. Recent progress also includes improved insights into the flare energy partition, on the location(s of energy release, tests of energy release scenarios and particle acceleration. The interplay of observations with theory is important to deduce the geometry and to disentangle the various processes involved. There is increasing evidence supporting reconnection of magnetic field lines as the basic cause. While this process has become generally accepted as the trigger, it is still controversial how it converts a considerable fraction of the energy into non-thermal particles. Flare-like processes may be responsible for large-scale restructuring of the magnetic field in the corona as well as for its heating. Large flares influence interplanetary space and substantially affect the Earth’s lower ionosphere. While flare scenarios have slowly converged over the past decades, every new observation still reveals major unexpected results, demonstrating that solar flares, after 150 years since their discovery, remain a complex problem of astrophysics including major unsolved questions.

  17. Flare Observations

    Science.gov (United States)

    Benz, Arnold O.

    2017-12-01

    Solar flares are observed at all wavelengths from decameter radio waves to gamma-rays beyond 1 GeV. This review focuses on recent observations in EUV, soft and hard X-rays, white light, and radio waves. Space missions such as RHESSI, Yohkoh, TRACE, SOHO, and more recently Hinode and SDO have enlarged widely the observational base. They have revealed a number of surprises: Coronal sources appear before the hard X-ray emission in chromospheric footpoints, major flare acceleration sites appear to be independent of coronal mass ejections, electrons, and ions may be accelerated at different sites, there are at least 3 different magnetic topologies, and basic characteristics vary from small to large flares. Recent progress also includes improved insights into the flare energy partition, on the location(s) of energy release, tests of energy release scenarios and particle acceleration. The interplay of observations with theory is important to deduce the geometry and to disentangle the various processes involved. There is increasing evidence supporting magnetic reconnection as the basic cause. While this process has become generally accepted as the trigger, it is still controversial how it converts a considerable fraction of the energy into non-thermal particles. Flare-like processes may be responsible for large-scale restructuring of the magnetic field in the corona as well as for its heating. Large flares influence interplanetary space and substantially affect the Earth's ionosphere. Flare scenarios have slowly converged over the past decades, but every new observation still reveals major unexpected results, demonstrating that solar flares, after 150 years since their discovery, remain a complex problem of astrophysics including major unsolved questions.

  18. Content Sharing Based on Personal Information in Virtually Secured Space

    Science.gov (United States)

    Sohn, Hosik; Ro, Yong Man; Plataniotis, Kostantinos N.

    User generated contents (UGC) are shared in an open space like social media where users can upload and consume contents freely. Since the access of contents is not restricted, the contents could be delivered to unwanted users or misused sometimes. In this paper, we propose a method for sharing UGCs securely based on the personal information of users. With the proposed method, virtual secure space is created for contents delivery. The virtual secure space allows UGC creator to deliver contents to users who have similar personal information and they can consume the contents without any leakage of personal information. In order to verify the usefulness of the proposed method, the experiment was performed where the content was encrypted with personal information of creator, and users with similar personal information have decrypted and consumed the contents. The results showed that UGCs were securely shared among users who have similar personal information.

  19. Large size space construction for space exploitation

    Science.gov (United States)

    Kondyurin, Alexey

    2016-07-01

    Space exploitation is impossible without large space structures. We need to make sufficient large volume of pressurized protecting frames for crew, passengers, space processing equipment, & etc. We have to be unlimited in space. Now the size and mass of space constructions are limited by possibility of a launch vehicle. It limits our future in exploitation of space by humans and in development of space industry. Large-size space construction can be made with using of the curing technology of the fibers-filled composites and a reactionable matrix applied directly in free space. For curing the fabric impregnated with a liquid matrix (prepreg) is prepared in terrestrial conditions and shipped in a container to orbit. In due time the prepreg is unfolded by inflating. After polymerization reaction, the durable construction can be fitted out with air, apparatus and life support systems. Our experimental studies of the curing processes in the simulated free space environment showed that the curing of composite in free space is possible. The large-size space construction can be developed. A project of space station, Moon base, Mars base, mining station, interplanet space ship, telecommunication station, space observatory, space factory, antenna dish, radiation shield, solar sail is proposed and overviewed. The study was supported by Humboldt Foundation, ESA (contract 17083/03/NL/SFe), NASA program of the stratospheric balloons and RFBR grants (05-08-18277, 12-08-00970 and 14-08-96011).

  20. Space closing versus space opening for bilateral missing upper laterals - aesthetic judgments of laypeople: a web-based survey.

    Science.gov (United States)

    Qadri, Salim; Parkin, Nicola A; Benson, Philip E

    2016-06-01

    To investigate the opinions of laypeople regarding the aesthetic outcome of treating patients with developmental absence of both maxillary lateral incisors using either orthodontic space closure (OSC) or space opening and prosthetic replacement (PR). Cross sectional, web-based survey. A panel of five orthodontists and five restorative dentists examined post-treatment intra-oral images of 21 patients with developmental absence of both upper lateral incisors. A consensus view was obtained about the 10 most attractive images (5 OSC; 5 PR). The 10 selected images were used in a web-based survey involving staff and students at the University of Sheffield. In the first section, the participants were asked to evaluate the attractiveness of the 10 randomly arranged single images using a 5-point Likert scale. In the second section, an image of OSC was paired with an image of PR according to their attractiveness ranking by the clinician panel, and the participants were asked to indicate which of the two images they preferred. The survey received 959 completed responses with 9590 judgements. The images of OSC were perceived to be more attractive (mean rating 3·34 out of 5; SD 0·56) compared with the images of PR (mean rating 3·14 out of 5; SD 0·58) (mean diff 0·21; P Space closing was perceived to be more attractive than space opening by lay people. The findings have implications for advising patients about the best aesthetic outcome when both maxillary lateral incisors are missing.