• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.3
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• pp.503-516
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• 2001

At present, environmental control system of greenhouses related with industrial automation in the korea is composed of on/off-type control machine using a timer in facilities requiring intensive labor. This system, however, makes it difficult for us to find out any status of environmental control system in greenhouses when we are situated in a remote area or at midnight. In this paper we improved a system to monitor status for manual and automatic control by means of PC by replacing an existing on/off-type controller with a display panel, It also attempts to implement DB for information on corps and to provide a user with the efficiency of getting information for plants.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.448-451
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• 2004

MSC (Multi-Spectral Camera) system is an electro-optical camera system which is being developed to be installed on KOMPSAT-2 satellite. High resolution image data from MSC system will be transmitted to the ground-station through x-band antenna called APS (Antenna Pointing System). APS is a directional antenna which will point to the receiving antenna at ground station while the satellite is passing over it. The APS needs to be controlled accurately to provide the reliable communication with big RF link margin. The APS is controlled by ATS (Antenna Tracking Software) which is included in the MSC software. ATS uses the closed loop control algorithm which will use TPF (Tracking Parameter File) as an input for antenna position, and will use two resolve readings from APS as a feedback. ATS has been developed and verified using APS QM (Qualification Model) and all the control parameters for ATS have been tested and verified. Various kinds of maximum, nominal and realistic dynamics for the APS movement have been simulated and verified. In this paper, closed loop servo control algorithm and obtained APS position error from the verification test with APS QM will be presented in detail

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.336-339
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• 2004

Communication, Ocean and Meteorological Satellite (COMS) has been developed by Korean Aerospace Research Institute (KARI) since 2003. Ocean Color Imager (OCI) is the one of COMS payloads, which will monitor the marine environment around Korean peninsula routinely with the intermediate resolution. But considering COMS is to be located in the geostationary orbit, required geographical coverage is not positioned in the nadir direction of COMS but in specific location with horizontal and vertical offsets from the nadir. In this study, coverage by OCI Field Of View (FOV) is analyzed. First of all, OCI is modeled as the sensor which is a $2,500{\times}2,500$ sized 2-D CCD and the pixel resolution is about 500m. And then, OCI is simulated to be controlled to target the required coverage accurately. As a result of it, coverage by OCI FOV is determined. Finally, all coverages by OCI FOV are mapped.

• Proceedings of the KSRS Conference
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• 2006.03a
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• pp.398-403
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• 2006

2008년 발사를 목표로 개발되고 있는 통신해양기상위성(COMS : Communication, Ocean and Meteorological Satellite)의 기상 탑재체를 이용한 기상 관측 임무는 기상청 기상위성센터(가칭)의 고유 임무로서, 이는 기상탑재체에서 관측한 자료를 수신 처리하여 고품질의 영상과 분석 자료를 생산하여 기상 예보 업무에 활용하고, 위성을 통하여 국내외 사용자들에게 분배하는 것 등을 포함한다. 위성을 통한 기상 자료 서비스는 국내에서는 최초로 시도되는 것으로, 국제기상위성운영 기관들의 모임인 기상위성조정그룹회의(CGMS Coordination Group for Meteorological Satellites)에서 권고하는 High Rate Information Transmission/Low Rate Information Transmission(HRIT/LRIT)라는 특정 자료 형태를 사용하여 분배하게 된다. 따라서 본 논문에서는 CGMS에서 권고하는 CCSDS (Consultative Committee for Space Data Systems) 전송 규격과 일본의 MTSAT-1R(Multi-functional Transport Satellite) 위성 사용자 서비스 자료 형태를 참고하여 통신해양기상위성의 효과적인 기상자료 분배를 위한 HRIT/LRIT 데이터 전송률을 분석하여 보았다.

• 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.

• Proceedings of the KSRS Conference
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• v.1
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• pp.159-162
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• 2006

This paper describes the ground system for COMS (Communication, Ocean, and Meteorological Satellite), the first Korean multi-purposed geostationary satellite, at MSC (Meteorological Satellite Center) in Korea. The overview of COMS MI (Meteorological Imager) will be introduced as well. KMA would implement mission planning for COMS MI operation and receive, process, interpret, disseminate, and archive MI data operationally for domestic and foreign user groups. Major missions of COMS MI are mitigation of natural hazard such as typhoon, dust storm, and heavy rain, and short-term warning of severe weather to protect human health and commerce. Moreover, research of climate variability and long-term changes will be supported. In accordance with those missions, the concept and design of COMPASS (COMS operation and meteorological products application service system), the ground system for COMS MI in MSC, have been setting up since 2004. Currently, COMPASS design is being progressed and will have finished the end of 2006. The development of COMPASS has three phases: first phase is development of fundamental COMPASS components in 2007, second phase is to integrate and test all of the COMPASS components in 2008, and the last phase is to operate COMPASS after COMS In-Orbit Tests in 2009.

• Proceedings of the KSRS Conference
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• v.1
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• pp.282-285
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• 2006

This paper analyzed the characteristics of the Lossy JPEG of the meteorological satellite image, and analyzed the quality of the Lossy JPEG compression, which is proper for the LRIT(Low Rate Information Transmission) to be serviced to the SDUS(Small-scale Data Utilization Station) system of the COMS(Communication, Oceans, Meteorological Satellite). Since COMS is to start running after 2008, we collected the data of the MTSAT-1R(Multi-functional Transport Satellite -1R) for analysis, and after forming the original image to be used to LRIT by each channel and time zone of the satellite image data, we set the different quality with the Lossy JPEG compression, and compressed the original data. For the characteristic analysis of the Lossy JPEG, we measured PSNR(Peak Signal to Noise Rate), compression rate and the time spent in compression following each quality of Lossy JPEG compression. As a result of the analysis of the satellite image data of the MTSAT-1R, the ideal quality of the Lossy JPEG compression was found to be 90% in the VIS Channel, 85% in the IR1 Channel, 80% in the IR2 Channel, 90% in the IR3 Channel and 90% in the IR4 Channel.

• Proceedings of the KSRS Conference
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• v.1
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• pp.82-85
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• 2006

The Geostationary Ocean Color Imager (GOCI) will be loaded in Communication, Ocean and Meteorological Satellite (COMS). To efficiently apply the GOCI data in the variety of fields, it is essential to develop the standard algorithm for estimating the concentration of ocean environmental components (, , and ). For developing the empirical algorithm, about 300 water samples and in situ measurements were collected from sea water around the Korean peninsula from 1998 to 2006. Two kinds of chlorophyll algorithms are developed by using statistical regression and fluorescence technique considering the bio-optical properties in Case-II waters. The single band algorithm for is derived by relationship between Rrs (555) and in situ concentration. The CDOM is estimated by absorption coefficient and ratio of Rrs(412)/Rrs(555). These standard algorithms will be programmed as a module of GOCI Data Processing System (GDPS) until 2008.

• Proceedings of the KSRS Conference
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• v.1
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• pp.220-223
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• 2006

The COMS(Communication, Ocean and Meteorological Satellite) EPS(Electrical Power Subsystem) is derived from an enhanced Eurostar 3000 EPS which is fully autonomous operation in normal conditions or in the event of a failure and provides a high level of reconfiguration capability and flexibility. This paper introduces the COMS EPS preliminary design result. The COMS EPS consists of a battery, a solar array wing, a PSR(Power Supply Regulator), a PRU(Pyrotechnic Unit), a SADM(Solar Array Drive Mechanism) and relay and fuse brackets. This can offer a bus power capability of 3 kW. The solar array is made of a deployable wing with two panels. One type of solar cells is selected as GaAs/Ge triple junction cells. Li-ion battery is base lined with ten series cell module of five cells in parallel. PSR associated with battery and solar array generates a power bus fully regulated 50 V. Power bus is centralised protection and distribution by relay and fuse brackets. PRU provides power for firing actuators devices. The solar array wing is routed by the SADM under control of the AOCS(Attitude Orbit Control Subsystem). The control and monitoring of the EPS especially of the battery, is performed by the PSR in combination with on-board software.

• Proceedings of the KSRS Conference
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• 2007.03a
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• pp.204-209
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• 2007

수중에서의 하향 방향의 감쇠 계수 (Diffuse attenuation coefficient of down-welling irradiance, $K_d$)에 대한 연구는 상충 해양에 대한 열전달 수중에서의 광합성 및 다른 생물학적 과정에 대한 연구，해양 일차 생산력 추정, 대양 및 연안에서의 탁도 추정 등에 대한 연구의 보조 자료로서 해양원격탐사를 포함한 해양에 대한 연구에 매우 중요한 요소이다. 우리나라는 세계 최초의 정지궤도 해색 센서인 Geostationary Ocean Color Imager (GOCI)를 2008년 말에 통신해양기상위성 (COMS, Communication Ocean and Meteorological Satellite)에 탑재하여 쏘아 올릴 계획에 있다. 이 센서는 매일 한 시간 간격으로 한반도 주변 해역을 8회 이상 관측할 계획에 었다. 따라서 기존의 해색 센서들에 비해서 시간 해상도가 향상되기 때문에 해양 환경 모니터링에 있어서 많은 도움이 될 것으로 예상된다. 본 연구에서는 앞으로 운영될 GOCI 센서에 대한 수중에서의 하향 방향의 감쇠계수 (The diffuse attenuation coefficient of down-welling irradiance, $K_d$) 알고리즘을 현장 관측 값을 이용하여 미리 만들어 보고 이를 현재의 대표적인 해색 센서인 SeaWiFS 영상의$K_d$(490) product와 비교하여 보았다.