• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.108-111
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• 2005

The Communication Ocean, Meteorological Satellite (COMS) as the one of the national space program has been developed by Korea Aerospace Research Institute (KARl). The Geostationary Ocean Color Imager (GOCI) is one of the main payloads ofCOMS which will provide consistent monitoring of ocean-colour around the Korean Peninsula from geostationary platforms. The ocean color observation from geostationary platform is required to remedy the coverage constraints imposed by polar orbiting platforms. In this paper the main characteristics of GOCI are described and compared with the current ocean color sensors. The GOCI will provide the measurement data of 6 visible channels and 2 nearinfrared channels (40Onm - 900nm). The high radiometric sensitivity is essential of ocean color sensor because of the weak water leaving radiance.

• 대한원격탐사학회지
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• 제29권6호
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• pp.601-610
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• 2013

As a standard water clarity variable, the vertical underwater visibility, called Secchi depth, is estimated with ocean color satellite data. In the present study, Moderate Resolvtion Imaging Spectradiometer (MODIS) data are used to measure the Secchi depth which is a useful indicator of ocean transparency for estimating the water quality and productivity. To estimate the Secchi depth $Z_v$, the empirical regression model is developed based on the satellite optical data and in-situ data. In the previous study, a semi-analytical algorithm for estimating $Z_v$ was developed and validated for Case 1 and 2 waters in both coastal and oceanic waters using extensive sets of satellite and in-situ data. The algorithm uses the vertical diffuse attenuation coefficient, $K_d$($m^{-1}$) and the beam attenuation coefficient, c($m^{-1}$) obtained from satellite ocean color data to estimate $Z_v$. In this study, the semi-analytical algorithm is validated using temporal MODIS data and in-situ data over the Yellow, Southern and East Seas including Case 1 and 2 waters. Using total 156 matching data, MODIS $Z_v$ data showed about 3.6m RMSE value and 1.7m bias value. The $Z_v$ values of the East Sea and Southern Sea showed higher RMSE than the Yellow Sea. Although the semi-analytical algorithm used the fixed coupling constant (= 6.0) transformed from Inherent Optical Properties (IOP) and Apparent Optical Properties (AOP) to Secchi depth, various coupling constants are needed for different sea types and water depth for the optimum estimation of $Z_v$.

• 대한원격탐사학회지
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• 제37권6_1호
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• pp.1507-1515
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• 2021

해색 원격 탐사를 통해 chlorophyll-a를 추정하면 식물성 플랑크톤, 해양일차생산력의 전 지구적 분포를 파악할 수 있다. 하지만 위성으로 관측된 해색 자료는 구름이나 기상 상황 등에 의하여 결측 데이터가 발생한다. 본 연구에서는 DINEOF를 이용하여 GOCI chlorophyll-a 산출물의 결측 자료를 복원하고자 하였다. DINEOF는 시·공간 자료에 기반을 두어 결측 자료를 복원하는 방법으로, 정확도는 GOCI chlorophyll-a 영상의 일부를 제거한 뒤 복원 영상과 비교하여 교차 검증하였다. 연구지역에서 DINEOF를 위한 최적의 EOF 모드는 10-13이었다. 시·공간 복원 자료 결과에서는 오후 시간대 chlorophyll-a 농도가 증가하는 경향이 반영되었고, 노이즈에 해당되는 이상치는 필터링 되는 효과를 보였다. 따라서 DINEOF는 결측이 발생한 영상에 대하여 복원 자료로 활용 가능할 것으로 보이며, 이를 통해 해양 환경 모니터링을 위한 기초 자료로 사용 가능할 것으로 판단된다.

• Ocean Science Journal
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• 제40권2호
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• pp.67-78
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• 2005

Complex physical, chemical and biological interactions off the Korean coast created several striking patterns in the phytoplankton blooms, which became conspicuous during the measurements of ocean color from space. This study concentrated on analyzing the spatial and temporal aspects of phytoplankton chlorophyll variability in these areas using an integrated dataset from a Sea-viewing Wide Field-of-view Sensor (SeaWiFS), Advanced Very High Resolution (AVHRR) sensor, and Conductivity Temperature Depth (CTD) sensor. The results showed that chlorophyll concentrations were elevated in coastal and open ocean regions, with strong summer and fall blooms, which appeared to spread out in most of the enclosed bays and neighboring waters due to certain oceanographic processes. The chlorophyll concentration was observed to range between 3 and $54\;mg\;m^{-3}$ inside Jin-hae Bay and adjacent coastal bays and 0.5 and $8\;mg\;m^{-3}$ in the southeast sea offshore waters, this gradual decrease towards oceanic waters suggested physical transports of phytoplankton blooms from the shallow shelves to slope waters through the influence of the Tsushima Warm Current (TWC) along the Tsushima Strait. Horizontal distribution of potential temperature $(\theta)$ and salinity (S) of water off the southeastern coast exhibited cold and low saline surface water $(\theta and warm and high saline subsurface water $({\theta}>12^{\circ}C; S>34.4)$ at 75dBar, corroborating TWC intrusion along the Tsushima Strait. An eastward branch of this current was called the East Korean Warm Current (EKWC), tracked with the help of CTD data and satellite-derived sea surface temperature, which often influenced the dynamics of mesoscale anticyclonic eddy fields off the Korean east coast during the summer season. The process of such mesoscale anticyclonic eddy features might have produced interior upwelling that could have shoaled and steepened the nutricline, enhancing phytoplankton population by advection or diffusion of nutrients in the vicinity of Ulleungdo in the East Sea.

• 한국수산과학회지
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• 제35권3호
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• pp.207-215
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• 2002

Ocean color properties can be quantified by the relationship between the band ratios of the sensor on the ocean color satellites and the measured field ocean color parameters, A tool to determine the abundance of primary organism using the observed ocean color properties from satellite is presented. Coincident to ocean color satellite passes over the Korean waters, the research vessels were deployed to survey the East Sea, the South Sea and the West Sea around the Korean waters, We have been able to have more than 101) data sets containing coincident in situ chlorophyll a and the estimated chlorophyll a derived from SeaWiFS (Sea-viewing Wide Field-of-view Sensor) from february, 1999 to October, 2001. We were able to develop three proper regional algorithms for the East Sea, the South Sea and the West Sea of the Korean peninsula to estimate chlorophyll a, and set up regional algorithms to quantify the suspended solid in the southern sea of the Korean peninsula, Futhermore we were successful in finding out a simple way of estimating chlorophyll a in the turbid water (Case 2 water) using the relationship between in situ chlorophyll a and the estimated chlorophyll a from the processed level 2 data, using the NASA's global algorithm.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.45-48
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• 2007

COMS satellite is a multipurpose satellite in the geostationary orbit, which accommodates multiple payloads of Meteorological Imager, Geostationary Ocean Color Imager and Ka band Satellite Communication Payload in a single spacecraft platform. In this paper, current status of Korea's first geostationary Communication, Ocean and Meteorological Satellte(COMS) program development is introduced. The satellite platform is based on the Astrium EUROSTAR 3000 communication satellite, but creatively combined with MARS Express satellite platform to accommodate three different payloads efficiently for COMS. The system design difficulties are in the different kinds of payload mission requirements of communication and remote sensing purposes and how to combine them into a single satellite to meet the overall satellite requirements. The COMS satellite critical design has been accomplished successfully to meet three different mission payloads. The platform is in Korea, KARI facility for the system integration and test. The expected launch target of COMS satellite is scheduled in June 2009.

• 대한원격탐사학회지
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• 제30권6호
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• pp.809-816
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• 2014

Ocean Color product들은 해양 생태계를 이해하기 위해 중요한 변수이다. 고위도 지역에서는 해빙이 바다로 유입되어 ocean color product에 광학적인 영향을 미친다. 본 연구에서는 북극 다산기지 근해의 피요르드에 대한 광학적 특성을 평가하고 높은 공간해상도를 가진 Landsat-8 OLI 영상의 엽록소-a(chlorophyll-a)와 부유물질(suspended sediment) 농도를 산출하고자 한다. 엽록소-a와 부유물질 농도를 추정하기 위해서 band ratio를 이용한 다양한 회귀 모델을 테스트했다. 위성영상과 관측된 실측 값과의 시간적인 차이 때문에 사용된 회귀모델은 높은 상관관계를 가지지는 못하였다. 하지만 Landsat-8 OLI 영상을 이용한 모델에서 생산된 엽록소-a와 부유물질 농도는 북극해 주변 피요르드와 해안지역에 대한 고해상도 위성 데이터를 활용한 모니터링 가능성을 보여주었다. 북극해 주변의 기후변화 패턴을 이해하기 위해서는 해양 생태계 변화에 ice meltig이 어떠한 영향을 미치는지를 이해하는 것이 필요하다. 본 연구의 결과는 고위도지역에서 ice melting이 해양생태계 변화에 미치는 영향을 고해상도로 모니터링을 하는데 사용된다. 극지연구소는 2002년부터 스발바드 다산기지을 운영하고 있으며 한국의 북극 기지를 기반으로 연구를 수행하였다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.49-52
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• 2007

This study uses empirical method to estimate absorption coefficient of colored dissolved organic matter $(a_{dom})$ from GOCI satellite data with the relationship between band ratio of remote sensing reflectance $(R_{rs})$ and $a_{dom}$. For development of $a_{dom}$ estimation algorithm, the used data is in-situ data about ocean optical properties in the around seawater area of the Korean Peninsula during 1998 - 2005. The relationship of $R_{rs}$(412)/$R_{rs}$(555), $R_{rs}$(443)/$R_{rs}$(555), $R_{rs}$(490)/$R_{rs}$(555), $R_{rs}$(510)/$R_{rs}$(555) and $a_{dom}$(412) showed $R^2$ values of 0.707, 0.707, 0.597 and 0.552, respectively. The spectrum of $a_{dom}({\lambda})$ is shape of exponential function $a_{dom}({\lambda})$ value decreases with increasing wavelength. For estimation of $a_{dom}$ from satellite data, we developed an algorithm from the relationship of $a_{dom}$(412) and $R_{rs}$(412)/$R_{rs}$(555). This algorithm was employed on SeaWiFS imagery to estimate $R_{rs}$(412) in the South Sea, East Sea, Yellow Sea and northern East China Sea areas. Also, SeaDAS-derived $a_{dg}$(412) from same SeaWiFS imagery, These $a_{dg}$(412) was then compared with in-situ and empirical-algorithm-derived $a_{dom}$(412), but these values were different. We think two points that such different values are caused by discrepancy related to failure of standard atmospheric correction scheme, the other are caused by error related to definition of $a_{dom}$(412) and $a_{dg}$(412).

• 정보과학회 컴퓨팅의 실제 논문지
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• 제23권3호
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• pp.171-176
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• 2017

최근, 효율적인 위성자료처리시스템의 개발을 위해 고성능 컴퓨팅, 클라우스 서비스, 데브옵스 방법론 등의 정보기술(information technology; IT)을 활용하는 연구가 활발히 진행되고 있다. 해양의 장단기 변화를 관측하여 해양재해 재난 예측 및 어장환경 관리를 지원하기 위해 정지궤도해양관측위성-II(Geostationary Ocean Color Imager II; GOCI-II)이 2019년 3월 발사될 예정이며, 자료 수신/처리/저장/배포를 위한 지상시스템(GOCI-II Ground Segment; G2GS)이 해양위성센터에서 설계되고 있다. G2GS는 자료수신(data acquisition subsystem; DAS), 자료보정(data correction subsystem; DCS), 정밀보정(precision correction subsystem; PCS), 자료처리(ocean data processing subsystem; ODPS), 자료관리(data management subsystem; DMS), 운영및품질관리(operation & quality management subsystem ; OQMS) 등 6개의 서브시스템으로 구성되어 있다. G2GS를 이용하여 GOCI-II로부터 생산된 해양 분석 자료를 유관기관 및 일반 사용자에게 실시간으로 제공할 수 있을 것이라 기대하고 있다.

• 대한원격탐사학회지
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• 제29권3호
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• pp.337-349
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• 2013

Communication Ocean Meteorological Satellite (COMS) for the hybrid mission of meteorological observation, ocean monitoring, and telecommunication service was launched onto Geostationary Earth Orbit on June 27, 2010 and it is currently under normal operation service on $128.2^{\circ}$ East of the geostationary orbit since April 2011. In order to perform the three missions, the COMS has 3 separate payloads, the meteorological imager (MI), the Geostationary Ocean Color Imager (GOCI), and the Ka-band antenna. The MI and GOCI perform the Earth observation mission of meteorological observation and ocean monitoring, respectively. For this Earth observation mission the COMS requires daily mission commands from the satellite control ground station and daily mission is affected by the satellite control activities. For this reason daily mission planning is required. The Earth observation mission operation of COMS is described in aspects of mission operation characteristics and mission planning for the normal operation services of meteorological observation and ocean monitoring. And the first one-year normal operation results after the In-Orbit-Test (IOT) are investigated through statistical approach to provide the achieved COMS normal operation status for the Earth observation mission.