• Title/Summary/Keyword: ocean color

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Characteristics of Ocean Scanning Multi-spectral Imager (OSMI)

  • Cho, Young-Min;Yong, Sang-Soon;Woo, Sun-Hee;Lee, Sang-Gyu;Oh, Kyoung-Hwan;Paik, Hong-Yul
    • Proceedings of the KSRS Conference
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    • 1998.09a
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    • pp.319-324
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    • 1998
  • Ocean Scanning Multispectral Imager (OSMI) is a payload on the Korean Multi-purpose SATellite (KOMPSAT) to perform worldwide ocean color monitoring for the study of biological oceanography. The instrument images the ocean surface using a whisk-broom motion with a swath width of 800 km and a ground sample distance (GSD) of < 1 km over the entire field-of-view (FOV). The instrument is designed to have an on-orbit operation duty cycle of 20% over the mission lifetime of 3 years with the functions of programmable gain/offset and on-board image data storage. The instrument also performs sun calibration and dark calibration for on-board instrument calibration. The OSMI instrument is a multi-spectral imager covering the spectral range from 400 nm to 900 nm using a CCD Focal Plane Array (FPA). The ocean colors are monitored using 6 spectral channels that can be selected via ground commands after launch. The instrument performances are fully measured for 8 basic spectral bands centered at 412nm, 443nm, 490nm, 510nm, 555nm, 670nm, 765nm and 865nm during ground characterization of instrument. In addition to the ground calibration, the on-board calibration will also be used for the on-orbit band selection. The on-orbit band selection capability can provide great flexibility in ocean color monitoring.

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Characteristics of the Real-Time Operation For COMS Normal Operation (천리안위성 정상 운영의 실시간 운영 특성)

  • Cho, Young-Min;Park, Cheol-Min;Kim, Bang-Yeop;Lee, Sang-Cherl
    • Journal of Satellite, Information and Communications
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    • v.8 no.2
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    • pp.80-87
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    • 2013
  • Communication Ocean Meteorological Satellite (COMS) has the hybrid mission of meteorological observation, ocean monitoring, and telecommunication service. The COMS is located at $128.2{\circ}$ east longitude on the geostationary orbit and currently under normal operation service 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 communication payload. The satellite controls for the three mission operations and the satellite maintenance are done by the real-time operation which is the activity to communicate directly with the satellite through command and telemetry. In this paper the real-time operation for COMS is discussed in terms of the ground station configuration and the characteristics of daily, weekly, monthly, seasonal, and yearly operation activities. The successful real-time operation is also confirmed with the one year operation results for 2011 which includes both the latter part of the In-Orbit-Test (IOT) and the first year normal operation of the COMS.

The Ground Checkout Test of OSMI on KOMPSAT-1

  • Yong, Sang-Soon;Shim, Hyung-Sik;Heo, Haeng-Pal;Cho, Young-Min;Oh, Kyoung-Hwan;Woo, Sun-Hee;Paik, Hong-Yul
    • Korean Journal of Remote Sensing
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    • v.15 no.4
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    • pp.297-305
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    • 1999
  • Ocean Scanning Multispectral Imager (OSMI) is a payload on the KOMPSAT satellite to perform global ocean color monitoring for the study of biological oceanography. The instrument images the ocean surface using a wisk-broom motion with a swath width of 800km and a ground sample distance (GSD) of < 1km over the entire field of view (FOV). The instrument is designed to have an on-orbit operation duty cycle of 20% over the mission lifetime of 3 years with the functions of programmable gain/offset and on-board image data compression/storage. The instrument also performs sun and dark calibration for on-board instrument calibration. The OSMI instrument is a multi-spectral imager covering the spectral range from 400nm to 900nm using CCD Focal Plane Array (FPA). The ocean colors are monitored using 6 spectral channels that can be selected via ground commands. KOMPSAT satellite with OSMI was integrated and the satellite level environment tests including instrument aliveness/functional test, such as launch environment, on-orbit environment (Thermal/Vacuum) and EMI/EMC test were performed at KARl. Test results met the requirements and the OSMI data were collected and analyzed during each test phase. The instrument is launched on the KOMPSAT satellite on December 21,1999 and is scheduled to start collecting ocean color data in the early 2000 upon completion of on-orbit instrument checkout.

Phototaxis of Fish (3) - Response of Rock bream and Grass Puffer to the Colored lights - (어류의 주광성에 관한 연구 (3) - 어광의 돌돔과 복섬의 반응 -)

  • 양용림
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.16 no.1
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    • pp.37-42
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    • 1980
  • The purpose of the present study is to find the color induced maximum gathering rate and to observed'the trend of the - gathering rate by using two species of commercial fishes: rock bream, Oplegnathus fasciatus (Temminet et Schlegel) and 'grass puffer, Fugu niphobles (Jordan et Snyder). An experimental tank($360L{\times}50W{\times}55H cm$) was set up in a dark room. An illumination system was attached to the two end of tank to fix horizontal light intensity by co~bination c' one light bulb(20W) and four filters (red, blue, yellow, white) and the five regulating filters in order to fix light intensity. During the experiment water depth was maintained 50 cm lever in the tank. The tank was marked into six longitudinal sections each being 60 em long to observe the distribution of fish. The fish were acclimatized in dark condition for 40 minutes prior to the main experiment. Upon turning on the light, the number of fish in each section was counted 40 times every 30 seconds, and the gathering rates ,were obtain from the average number of fish in each secion. The color induced maximum gathering rate of rock bream appeared to be red, blue yellow and white color orderly.However, that of grass puffer appeared to be blue, white, yellow and red color orderly. Trend of the gathering rate in illumination time showed the remarkable fluctuation in the rock bream and little difference at the two color light sources. However, trend of the gathering rate in illumination time showed the little fluctuation in grass puffer and much difference at the two color light sources.

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MEASUREMENT OF SPECTRAL-ANGULAR RADIANCES OF COASTAL WATERS IN THE KOREAN SOUTH SEA

  • Ahn, Yu-Hwan;Shanmugam, Palanisamy;Ryu, Joo-Hyung;Moon, Jeong-Eon
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.156-158
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    • 2007
  • The radiance observed from the ocean depends on the illumination and viewing geometry along with the water properties, and this variation is called the bidirectional effect which is important to be considered in ocean color remote sensing. In the present study, as a preliminary step, the spectral-angular radiances in coastal water were investigated with experiments for a range of viewing geometric conditions $(0-70^{\circ})$. Over a phytoplankton-dominated water surface the upward radiance for visible and near-infrared wavelengths (example, SeaWiFS and GOCI) increased at nadir and decreased toward the near-horizon, becoming dependent of viewing angles (with higher radiance at nadir view angle and lower radiance at near-horizon viewing angle). This variations were better expressed by the Q-factor, which relates upwelling radiance to the upwelling irradiance (i.e., $Q=E_u/L_u$, also dependent on Sun's position). The Q-factor for this case was more non-uniform with the considered wavelengths and was dependent on viewing geometric conditions. These experimental results confirm the previous similar findings in other coastal waters.

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A STUDY ON THE DIFFUSE ATTENUATION COEFFICIENT OF DOWN-WELLING IRRADIANCE AROUND THE YELLOW SEA

  • Min, Jee-Eun;Ahn, Yu-Hwan;Ryu, Joo-Hyung;Lee, Kyu-Sung
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.459-462
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    • 2006
  • The diffuse attenuation coefficient for down-welling irradiance ($K_d$) is an important parameter for ocean studies including remote sensing applications. For the vast ocean, ocean color remote sensing is the only possible means to get the fine-scale measurements of $K_d$. To develop a technique of estimating $K_d$ from remotely sensed data, the following underwater optical parameters (absorption coefficient (a), attenuation coefficient (c), scattering coefficient (b), diffuse attenuation coefficient ($K_d$), etc.) have been studied. For this research we conducted the field campaign around the Yellow Sea at $8{\sim}9$ June, 2006. We obtained a set of underwater optical parameter data: down-welling irradiance ($E_d$), up-welling irradiance ($E_u$) and up-welling radiance ($L_u$) using TriOS optical sensors and a, c coefficient using Spectral Absorption and Attenuation Meter (AC-S). We then derived $K_d$ values from $E_d$ for each depth.

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ON-ORBIT THERMAL ANALYSIS FOR THE GEOSTATIONARY OCEAN COLOR IMAGER OF A GEOSTATIONARY SATELLITE (정지궤도위성의 해양관측센서 임무 궤도 열해석)

  • Kim, Jung-Hoon;Jun, Hyoung-Yoll
    • 한국전산유체공학회:학술대회논문집
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    • 2009.04a
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    • pp.135-141
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    • 2009
  • A preliminary thermal analysis is performed for the optical payload system of a geostationary satellite. The optical payload considered in this paper is GOCI(Geostationary Ocean Color Imager) of COMS of Korea. The radiative and conductive thermal models are employed in order to predict thermal responses of the GOCI on the geostationary orbit. According to the results of this analysis are as follows: 1) the GOCI instrument thermal control is satisfactory to provide the temperatures for the GOCI performances, 2) the thermal control is defined and interfaces are validated, and 3) the entrance baffle temperature is found slightly out its specification, therefore further detailed analyses should be continued on this element.

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PRELIMINARY ON-ORBIT THERMAL ANALYSIS FOR THE GEOSTATIONARY OCEAN COLOR IMAGER OF COMS (통신해양기상위성 해양탑재체 정지궤도 예비 열해석)

  • Kim, Jung-Hoon;Jun, Hyoung-Yoll;Han, Cho-Young
    • Journal of computational fluids engineering
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    • v.15 no.1
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    • pp.24-30
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    • 2010
  • A preliminary thermal analysis is performed for the optical payload system of a geostationary satellite. The optical payload considered in this paper is GOCI(Geostationary Ocean Color Imager) of COMS of Korea. The radiative and conductive thermal models are employed in order to predict thermal responses of the GOCI on the geostationary orbit. The results of this analysis are as follows: 1) the GOCI instrument thermal control is satisfactory to provide the temperatures for the GOCI performances, 2) the thermal control is defined and interfaces are validated, and 3) the entrance baffle temperature and shutter wheel motor gradient are found slightly out their specification, therefore further detailed analyses should be continued on these elements.

Development of sea water cooling apparatus for fish hold storage (어창용 해수 냉각장치 개발에 관한 연구)

  • 조영제
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.35 no.1
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    • pp.60-64
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    • 1999
  • The objective of this study was to manufacture the sea water cooling apparatus for fish hold storage to extend the freshness of fish. Using the sea water cooling apparatus manufactured, it makes observations on the physicochemical and sensual properties of mackerel such as ATP and its related compounds, K-value, VBN, TMA, TBA, salt-concentration and skin color through storage. The results of this investigation showed that the values of physicochemical properties such as ATP and its related compounds, K-value, VBN, TMA, TBA increased gradually during storage in sea water cooling apparatus manufactured and the changes of skin color was inhibited also. From these results, it could be suggested that developed sea water cooling apparatus is effective in shelf-life extension of fishes.

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Influence of atmospheric aerosol on satellite ocean color data in the East/Japan Sea (동해에서 대기에어로졸이 해색위성자료에 미치는 영향)

  • Yamada, Keiko;Kim, Sang-Woo
    • Proceedings of KOSOMES biannual meeting
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    • 2009.06a
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    • pp.53-54
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    • 2009
  • The influence of atmospheric aerosol on satellite ocean color data were evaluated using SeaWiFS monthly standard mapped image products. The atmospheric optical thickness (AOT) was increased in spring and summer, and it showed the strong positive correlation with remote sensing reflectance, normalized waterleaving radiance /solar irradiance, at 555 nm (Rrs555) which is a component of the satellite chlorophyll estimation. Such the high AOT and high Rrs555 pixels showed overestimation of satellite chlorophyll in spring, especially in the area which showed large phytoplankton absorption which 1s expressed by low remote sensing reflectance at 443, 490 and 510 nm (Rrs 443, Rrs490 and Rrs510).

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