• Proceedings of the KSRS Conference
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• v.1
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• pp.208-211
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• 2006

The contents of RF test set which can be used for checking the function and performance of 13m antenna installed in KARI site are described in this paper. For the purpose of considering RF test set as the transceiver in COMS, it is designed to retransmit the LRIT and HRIT in L-Band after receiving them in S-Band from 13m antenna. Additionally, this set has a function to turnaround raging tone used for the measurement of distance between satellite and 13m antenna. The required all equipments of RF test set are summarized with configuration. Measurements of several equipments which have already been delivered are described in this paper. The assembled RF test set will be used for the verification of 13m antenna

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.564-566
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• 2005

The relation between HPA (High Power Amplifier) and COMS (Communication Ocean Meteorological Satellite) multi-carrier is analyzed in this paper. MODAC (Meteorological and Ocean Data Application Center) has a primary mission to transmit processed data, HRIT (High Rate Information Transmission) and LRIT (Low Rate Information Transmission), which is normalized and calibrated by pre-processing. It is also replaced with the SOC (Satellite Operation Center) in emergency case and can transmit the command and ranging tones for operation of COMS. From the result of simulation with modelled HPA, it is found that the multi-carrier in one HPA can give rise to an inter-modulation which makes harmonic and spurious elements increase in-band. Under the environment of these increased parasitic elements, the degradation of multi-carrier's quality is estimated from the ratio of the amount of noise to total output power of HPA.

• Proceedings of the KSRS Conference
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• v.1
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• pp.204-207
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• 2006

COMS will receive two different meteorological signals in S-Band from IDACS (Image Data Acquisition and Control System) in ground station before transmitting them in L-Band to user station. MODCS (Meteorological Ocean Data Communication Subsystem) in satellite released the value of required PFD (Power Flux Density) to receive two signals. Thus, DATS (Data Acquisition and Transmission Subsystem) needs to send two signals to satellite with a satisfied EIRP. The value of minimum HPA (High Power Amplifier) output power was estimated by subtracting antenna directional gain and path loss between antenna and HPA from the needed EIRP in this paper. Besides the minimum output power of HPA, the maximum output power was also calculated with considering IMD (Inter-Modulation Distortion) characteristics. IMD is always occurred in the output of HPA when LRIT and HRIT are amplified by using single HPA as COMS application. In this paper, the setting of maximum output power was determined when the IMD of modelled HPA was corresponded to the requirement of MODCS.

• Journal of Astronomy and Space Sciences
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• v.25 no.4
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• pp.471-480
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• 2008

COMS Image Data Acquisition and Control System (IDACS) plays a key role in real time ground processing of Meteorological and Ocean observation data. Beyond processing, it serves processed image data and additional data to end users through the spacecraft in the internationally recommended format. The IDACS will be installed at three location (MSC, KOSC, and SOC) and automatically operated 24h/365days. After the IDACS subsystem tests and inter -subsystem interface tests had been completed in the first half of 2008, the acceptance test which was a comprehensive test performed as an integrated form to verify function performance and operational requirements. This paper introduces test objective, preparation, and major result of the COMS IDACS acceptance test.

• Journal of Satellite, Information and Communications
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• v.6 no.2
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• pp.1-9
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• 2011

The Communication Ocean and Meteorological Satellite(COMS), the first geostationary observation satellite, was successfully launched on June 27th in 2010. The raw data of Meteorological Imager(MI) and Geostationary Ocean Color Imager(GOCI), the main payloads of COMS, is delivered to end-users through the on-ground processing. The COMS Image Data Acquisition and Control System(IDACS) developed by Korea Aerospace Research Institute(KARI) in domestic technologies performs radiometric and geometric corrections to raw data and disseminates pre-processed image data and additional data to end-users through the satellite. Currently the IDACS is in the nominal operations phase after successful in-orbit testing and operates in National Meteorological Satellite Center, Korea Ocean Satellite Center, and Satellite Operations Center, During the in-orbit test period, validations on functionalities and performance IDACS were divided into 1) image data acquisition and transmission, 2) preprocessing of MI and GOCI raw data, and 3) end-user dissemination. This paper presents that IDACS' operational validation results performed during the in-orbit test period after COMS' launch.