• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.482-484
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• 2003

GLI on boarded ADEOS-II satellite allows us to observe vegetation status in the two different resolutions simultaneously, because of thirty 1km resolution channels and six 250m resolution channels. There are four GLI land higher level products from these channels ; those are PGCP (Precise Geometric Correction Parameter), L2A_LC (TOA reflectance), ACLC (atmospheric corrected reflectance), and VGI (NDVI and EVI). This paper shows ADEOS-II GLI land data processing, and some of the latest results.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1236-1238
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• 2003

The Earth's total magnetic field was extracted from on board TAM (Three Axis Magnetometer) observations of KOMPSAT-1 satellite between June 19th and 21st, 2000. In the pre-processing, the TAM's telemetry data were transformed from ECI (Earth Centered Inertial frame) to ECEF (Earth Centered Earth Fixed frame) and then to spherical coordination, and self-induced magnetic field by satellite bus itself were removed by using an on-orbit magnetometer data correction method. The 2-D wavenumber correlation filtering and quadrant-swapping method were applied to the pre-processed data in order to eliminate dynamic components and track-line noise, respectively. Then, the spherical harmonic coefficients are calculated from KOMPSAT-1 data. To test the validity of the TAM's geomagnetic field, Danish/NASA/French ${\phi}$rsted satellite's magnetic model and IGRF2000 model were used for statistical comparison. The correlation coefficient between ${\phi}$rsted and TAM is 0.97 and IGRF and TAM is 0.96. It was found that the data from on board magnetometer observations for attitude control of Earth-observing satellites can be used to determinate the Earth's total magnetic field and that they can be efficiently used to upgrade the global geomagnetic field coefficients, such as IGRF by providing new information at various altitudes with better temporal and spatial coverage.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.367-370
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• 2006

A GPS-based time synchronization technique employing a refined HW circuitry and SW algorithm is considered as fine time-management system for Low Earth Orbit (LEO) remote sensing satellites. By synchronizing the On-Board Time (OBT) within satellites to the GPS 1PPS, a very expensive, highly accurate on-board clock is not required to determine the precise on-board time management. Also, the satellite command generation in ground stations and postprocessing of earth observation data which a particular image is acquired. This paper analyses on-orbit verification of the existing satellite time sync architecture and presents a new time sync architecture, operation and relation between the OBT and the GPS time.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.212-215
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• 2004

GOES-9 has been operated with the status of the Image Motion Compensation(IMC) off since last October. As the IMC function turned off, the sub-satellite point(SSP) of GVAR data was changed with the effect of the satellite motions. This makes the image registration, to maintain pixels within an image and between successive images to their earth-referenced information, not to be possible any more. In the paper, we introduce the method to accomplish image registration and the result of the SSP observation with the status of IMC off.

• Aerospace Engineering and Technology
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• v.12 no.2
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• pp.64-73
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• 2013

In order to observe the deep space more efficiently, a satellite installed with a telescope on earth is needed. Advanced countries in space such as U.S.A and E.U. etc. have obtained and analyzed informations and images of the space from Hubble telescope, Kepler space observatory and Herschel space observatory. This paper studied specifications and operation status of space observation satellite of the several foreign countries and described technologies and plans for the domestic deep space observation satellite.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.8A
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• pp.1149-1155
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• 1999

LEO(Low altitude Earth Orbit) Satellite systems have been utilized in the field of earth and scientific observation (cartography mission, ocean color monitoring, bioglogical coeanography, space environments observation by space physics sensor, and meteorological observation, atmospheric observation etc.), and the field of military (military communications and secret information, enemy reconnaissance etc.), and recently been developing in the field of mobile satellite commnication of GMPCS for commercial utilization. In Korea, KOMPSAT I satellite and ground system are been developing and planed to be lunched on October 1999 In this paper, the link budge of the TT&C system for LEO satellite is described and the relations between elevation angle and pass time of LEO satellite are calculated according to satellite moving. And the packet error rates of receiving data are derived three packet error rates(PER) of real-time(RT) mode, playback(PB) mode, and real-time and range tone(RT+RNG) mode are estimated according to pass time of satellite. The results of PER are the best at real-time and the worst at real-time mode and range mode at the all pass time of satellite. The average error free packet(EFP)s of real-time mode, playback mode, and real-time and range tone for the pass time of satellite are obtained as 99.999999%, 99.999912%, 99.995945% respectively. Therefore, transmission sequence of telemetry data are determined such as PER sequence according to pass time, namely, real-time, playback, and real-time and range mode.

• Proceedings of the KSRS Conference
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• v.2
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• pp.959-962
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• 2006

Public education is undoubtedly a very important aspect for a country to develop space program. People have the rights to understand how the tax they paid is being used. This paper addresses the effectiveness of FORMOSAT-2 on public education in Taiwan. As the first remote sensing satellite of the National Space Organization (NSPO) of Taiwan, FORMOSAT-2 is a small satellite of 746 kg mass for two remote sensing missions: Earth and upward lightning observations. The mission orbit is sun-synchronous of 888 km altitude for exactly 14 revolutions per day. For earth observation, the payload is an advanced high resolution remote sensing instrument (RSI) with ground sampling distance (GSD) 2 m in panchromatic (PAN) band and 8 m in four multi-spectral (MS) bands. For upward lightning observation, the payload is an imager of sprites and upper atmospheric lightning (ISUAL). After more than two years of Earth observation started in June 2004, the effectiveness of FORMOSAT-2 images on public education in Taiwan is very promised. Five domestic universities and one private company in Taiwan have signed contracts respectively with NSPO to take the roles of satellite image investigator and distributor. A private company has signed contract with NSPO to generate and provide URMAP (= your map) in its website for general public applications by using FORMOSAT-2 images. The Newtonkids Book Company used FORMOSAT-2 images to publish a kind of calendar for children education purpose. Besides, a science team in National Cheng Kung University (NCKU) is doing the research work on the 3820 (up to 30 June 2006) transient luminous events (TLEs) observed by FORMOSAT-2.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.05a
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• pp.123-126
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• 2002

Acoustic vibration analysis has been performed using random vibration analysis module of MSC/NASTRAN to evaluate the safety of the composite satellite antenna structure under the acoustic pressure from the launch vehicle. It was found that maximum $3\sigma$ stress by acoustic excitation was less than allowable stress.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.35-38
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• 2004

We developed a Near Real-Time Validation System (NRVS) for the Level-2 Products of AQUA Satellite. AQUA satellite is the second largest project of Earth Observing System (EOS) mission of NASA. This satellite provides the information of water cycle of the entire earth with many different forms. Among its products, we have used five kinds of level-2 geophysical parameters containing rain rate, sea surface wind speed, skin surface temperature, atmospheric temperature profile, and atmospheric humidity profile. To use these products in a scientific purpose, reasonable quantification is indispensable. In this paper we explain the near real-time validation system process and its detail algorithm. Its simulation results are also analyzed in a quantitative way. As reference data set in-situ measured meteorological data which are periodically gathered and provided by the Korea Meteorological Administration (KMA) is processed. Not only site-specific analysis but also time-series analysis of the validation results are explained and detail algorithms are described.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.686-689
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• 2006

SAC is earth observation camera being developed by satrec initiative. It provides 10m in multi-spectral channel and 50km swath width at 685km altitude. The EQM of SAC has been developed and tested. In this paper, the procedure and result of the vibration test of SAC to validate structural design and to verify structural toughness are described.