• 제목/요약/키워드: Orbit Illumination

검색결과 36건 처리시간 0.024초

Illumination Variations in Near-Equatorial Orbit Imaging: A Case Study with Simulated Data of RAZAKSAT

  • Hassan, Aida-Hayati-Mohd;Hashim, Mazlan;Arshad, Ahmad-Sabirin
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.1052-1054
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    • 2003
  • RAZAKSAT is a second micro-satellite mission by Malaysian Satellite Program and is expected for launch in June 2004. Designed to orbit the earth at low-equatorial orbit, RAZAKSAT will meet Malaysia’s immediate needs to rapid data acquisition (real time and more repetitions) to address many operational issues of remote sensing applications, which require availability of current data sets. RAZAKSAT will be among the first remote sensing satellite to orbit the earth at low inclination along the equator, 9$^{\circ}$ with 685km altitude, hence, allows optimal geographical information and environment change within equatorial region be observed with a unique revisit characteristics. The satellite primary payload is MAC, a push-broom type camera with 2.5m of ground sampling distance (GSD) in panchromatic band and 5m of GSD in four multi-spectral bands. This paper describes on the variation of illumination anticipated from simulated RAZAKSAT image, examine its implication to its ground leaving radiances for major applications.

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Assessment of Earth Remote Sensing Microsatellite Power Subsystem Capability during Detumbling and Nominal Modes

  • Zahran M.;Okasha M.;Ivanova Galina A.
    • Journal of Power Electronics
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    • 제6권1호
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    • pp.18-28
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    • 2006
  • The Electric Power Subsystem (EPS) is one of the most critical systems on any satellite because nearly every subsystem requires power. This makes the choice of power systems the most important task facing satellite designers. The main purpose of the Satellite EPS is to provide continuous, regulated and conditioned power to all the satellite subsystems. It has to withstand radiation, thermal cycling and vacuums in hostile space environments, as well as subsystem degradation over time. The EPS power characteristics are determined by both the parameters of the system itself and by the satellite orbit. After satellite separation from the launch vehicle (LV) to its orbit, in almost all situations, the satellite subsystems (attitude determination and control, communication and onboard computer and data handling (OBC&DH)), take their needed power from a storage battery (SB) and solar arrays (SA) besides the consumed power in the EPS management device. At this point (separation point, detumbling mode), the satellite's angular motion is high and the orientation of the solar arrays, with respect to the Sun, will change in a non-uniform way, so the amount of power generated by the solar arrays will be affected. The objective of this research is to select satellite EPS component types, to estimate solar array illumination parameters and to determine the efficiency of solar arrays during both detumbling and normal operation modes.

Stray Light Analysis of High Resolution Camera for a Low-Earth-Orbit Satellite

  • Park, Jun-Oh;Jang, Won-Kweon;Kim, Seong-Hui;Jang, Hong-Sul;Lee, Seung-Hoon
    • Journal of the Optical Society of Korea
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    • 제15권1호
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    • pp.52-55
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    • 2011
  • We discuss the effect of stray light on a high-precision camera in an LEO(Low Earth Orbit) satellite. The critical objects and illumination objects were sorted to discover the stray light sources in the optical system. Scatter modeling was applied to determine a noise effect on the surface of a detector, and the relative flux of a signal and noise were also calculated. The stable range of reflectivity of the beam splitter was estimated for various scattering models.

Hot Wall Epitaxy (HWE)에 의한 성장된 $ZnIn_2S_4$ 단결정 박막의 광전류 특성 (Opto-electric Properties of $ZnIn_2S_4$ single crystal thin film Grown by Hot Wall Epitaxy method)

  • 홍광준;이상열
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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    • pp.71-72
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    • 2006
  • The stochiometric mixture of evaporating materials for the $ZnIn_2S_4$ single crystal thin film was prepared from horizontal furnace. To obtain the $ZnIn_2S_4$ single crystal thin film. $ZnIn_2S_4$ mixed crystal was deposited on throughly etched semi-insulating GaAs(100). In the Hot Wall Epitaxy(HWE) system. From the photocurrent spectrum by illumination of perpendicular light on the c-axis of the $ZnIn_2S_4$ single crystal thin film, we have found that the values of spin orbit splitting ${\Delta}So$ and the crystal field splitting ${\Delta}Cr$ were 0.0148 eV and 0.1678 eV at $10_{\circ}K$, respectively.

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Digital Image Simulation of Electro-Optical Camera(EOC) on KOMPSAT-1

  • Shim, Hyung-Sik;Yong, Sang-Soo;Heo, Haeng-Pal;Lee, Seung-Hoon;Oh, Kyoung-Hwan;Paik, Hong-Yul
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 1999년도 Proceedings of International Symposium on Remote Sensing
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    • pp.349-354
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    • 1999
  • Electro-Optical Camera (EOC) is the main payload of the KOMPSAT-1 satellite to perform the mission of cartography that builds up a digital map of Korean territory including a digital terrain elevation map. This paper discusses the issues of the digital image simulation of EOC for the generation of EOC simulated scene as taken by EOC at 685km altitude on orbit. For the purpose, simulation work has been performed with the sensor models of EOC and the satellite platform motions models through image chain analysis from the illumination source (Sun) to a simulated image output in digital number. MODTRAN fur radiance calculation, MTF models of optics, detector and motions of EOC for system point spread function (PSF), and signal chain equations for digital number output are described. Several noise models of EOC are also considered. The final output is the EOC simulated image in digital number. The simulation technique can be used in several phase of a spaceborne electro-optical system development project, feasibility study phase, design, manufacturing, test phases, ground image processing phases, and so on.

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HWE(Hot Wall Epitaxy)에 의한 태양 전지용 박막성장과 특성에 관한 연구 (The Study of Growth and Characterization of CuGaSe$_2$ Sing1e Crystal Thin Films for solar cell by Hot Wall Epitaxy)

  • 홍광준
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 하계학술대회 논문집
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    • pp.237-242
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    • 2001
  • The stochiometric mix of evaporating materials for the CuGaSe$_2$ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films, CuGaSe$_2$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperature were 610$^{\circ}C$ and 450$^{\circ}C$, respectively The crystalline structure of single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). From the photocurrent spectrum by illumination of perpendicular light on the c-axis of the CuGaSe$_2$ single crystal thin film, we have found that the values of spin orbit splitting Δ So and the crystal field splitting ΔCr were 91 meV and 249.8 meV at 20 K, respectively. From the Photoluminescence measurement on CuGaSe$_2$ single crystal thin film, we observed free excition (Ex) existing only high quality crystal and neutral bound exiciton (D$^{\circ}$,X) having very strong peak intensity. Then, the full-width-at-half-maximum(FWHM) and binding energy 7f neutral acceptor bound excision were 8 meV and 35.2 meV, respectivity. By Haynes rule, an activation energy of impurity was 355.2 meV

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자연채광성능 평가를 위한 태양고정형 Heliodon의 유용성 검증에 관한 연구 (A Study on the Validation of Heliodon for Daylighting Performance Evaluation)

  • 김정태;이지현;김곤
    • 한국태양에너지학회 논문집
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    • 제24권2호
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    • pp.51-62
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    • 2004
  • Architects may evaluate building models to see how a building will shadow itself and its neighbors at various times. A heliodon, a tilt-table which is a machine that imitates the rotation and orbit of the Earth, helps architects wanting to analyze patterns of shadow patch, passive solar heating options, site solar panels, or control solar heat gain. The heliodon swivels in three directions for setting latitude, season, and time of day. Using the device, an architect first clamps a model to the tabletop, then turns the table to the coordinates of interest. Usually, the winter and summer solstices receive strong attention, for they represent extreme cases, A more recent installation at a university adds to its heliodon a set of lamps to recreate the illumination level and more accurate patterns of shadow patch. The table holds the building model at various angles to a spotlight, which mounts in the pole. The set of scale model measurement describes the validity of various electric lamps as an artificial sun to approximate the sun's parallel rays, helping designers to distinguish between illuminated areas in and around a building and those regions falling in the shadows.

Regional Renaissance and Rejuvenated Civilization in Japan for Sustainable Development and Global Innovation: Focusing on the Industry-Academia-Government Collaboration's Context

  • Miyakawa, Yasuo
    • World Technopolis Review
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    • 제6권1호
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    • pp.1.1-1.34
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    • 2017
  • This paper aims to illuminate the role of serial context among industry, academia and government, taking much care of the role of society and community in the sustainable regional planning and practice. This paper is composed of five chapters, each of them dealing with different aspects. In In chapter 1, we give the little long introduction of the time of mutation and significance of locus that explains the conceptual background and framework of this paper. In chapter 2, we elaborate on the mutation and metamorphosis of structural, social, and natural changes in the world and especially Japan. In chapter 3 and chapter 4, the main chapters of this paper, we describe the evolution of academic town in megalopolis, the revitalization of technopolis, and the creative local culture of the World Heritage for the regional renaissance in Japan. In chaper 5, we conclude this paper. As for this illumination, we should pay more due regards to the locus, orbit and iconography of region to develop better hosting environment and habitat for global innovation of industry-academia-government collaboration's serial contexts through sustainable tourism and tourism sustainability. Especially, at the time of natural and social mutation, we could not look over the heavy and sudden natural unexpected changes, the deep structural social and community changes in Japan, and war and terrorism in Asia on the global scene for sustainable rejuvenation.

Global Patterns of Pigment Concentration, Cloud Cover, and Sun Glint: Application to the OSMI Data Collection Planning

  • Kim, Yong-Seung;Kang, Chi-Ho;Lim, Hyo-Suk
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 1998년도 Proceedings of International Symposium on Remote Sensing
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    • pp.387-392
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    • 1998
  • To establish a monthly data collection planning for the Ocean Scanning Multispectral Imager (OSMI), we have examined the global patterns of three impacting factors: pigment concentration, cloud cover, and sun glint. Other than satellite mission constraints (e.g., duty cycle), these three factors are considered critical for the OSMI data collection. The Nimbus-7 Coastal Zone Color Scanner (CZCS) monthly mean products and the International Satellite Cloud Climatology Project (ISCCP) monthly mean products (C2) were used for the analysis of pigment concentration and cloud cover distributions, respectively. And the monthly simulated patterns of sun glint were produced by performing the OSMI orbit prediction and the calculation of sun glint radiances at the top-of-atmosphere (TOA). Using monthly statistics (mean and/or standard deviation) of each factor in the above for a given 10$^{\circ}$ latitude by 10$^{\circ}$ longitude grid, we generated the priority map for each month. The priority maps of three factors for each month were subsequently superimposed to visualize the impact of three factors in all. The initial results illustrated that a large part of oceans in the summer hemisphere was classified into the low priority regions because of seasonal changes of clouds and sun illumination. Sensitivity tests were performed to see how cloud cover and sun glint affect the priority determined by pigment concentration distributions, and consequently to minimize their seasonal effects upon the data collection planning.

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$AgInS_2$ 단결정 박막 성장과 광센서 특성 (Growth and Photosensor Properties for $AgInS_2$ Single Crystal Thin Film)

  • 홍광준;백승남
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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    • pp.134-135
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    • 2006
  • $AgInS_2$ single crystal thin filmsl was deposited on throughly etched semi-insulator GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperature were $680^{\circ}C$ and $410^{\circ}C$ respectively, and the thickness of the single crystal thin films is $6{\mu}m$. From the photocurrent spectrum by illumination of perpendicular light on the c-axis of the $AgInS_2$ single crystal thin film, we have found that the values of spin orbit coupling ${\Delta}So$ and the crystal field splitting ${\Delta}Cr$ were 0.0098 eV and 0.15 eV at 10 K, respectively. In order to explore the applicability as a photoconductive cell, we measured the sensitivity ($\gamma$), the ratio of photocurrent to darkcurrent (pc/dc), maximum allowable power dissipation (MAPD), spectral response and response time. The result indicated that the samples annealed in S vapour the photoconductive characteristics are best. Therefore we obtained the sensitivity of 0.98, the value of pc/dc of $1.02{\times}10^6$, the MAPD of 312 mW, and the rise and decay time of 10.4ms and 10.8ms respectively.

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