• Title/Summary/Keyword: Satellite Oceanography

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Estimation of the Range of the Suspended Solid from the Nakdong River using Satellite Imageries and Numerical Model (위성영상 및 수치모델을 이용한 낙동강유출 부유토사 확산범위 추정)

  • Hwang, Jae-Dong;Kang, Yong Q.;Suh, Yong-Sang;Cho, Kyu Dae;Park, Sung Eun;Jang, Lee-Hyun;Lee, Na Kyung
    • Journal of the Korean Association of Geographic Information Studies
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    • v.5 no.2
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    • pp.25-33
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    • 2002
  • We were trying to understand indirectly the range of the discharge from the Nakdong with the dispersion of suspended solid(SS) related to the amount of discharge from river in this study. The range of dispersion of SS from the Nakdong was estimated using satellite remote sensing and numerical modeling. The stream field with two dimensional and numerical model using the condition of integrated depth was calculated. According to the results, the streamline flowed from Busan to the Jinhae Bay and Geojae Island. at the flood. The situation at the ebb was totally changed. The streamline flowed out Busan from the Bay. The velocity in offshore was faster than one at coastal water of the Nackdong. Residual current which was averaged during 12hours dominantly appeared the dominant direction from the southwestern part of the Nackdong to the northeastern part of it. The eastward current appeared at the eastern coast of Gaduck Is. Base on the results of the velocity field, the quantifying of the dispersion of SS was estimated by the method of numerical tracer related to the Lagrangian method. The significant range of the dispersion of the SS from the Nackdong was from the eastern coast of Gaduck Is, to the coastal areas of Busan, Korea. The estimated range of the dispersion of the SS using the SeaWiFS and Landsat satellite data was similar to the estimated results using the numerical model.

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Can we obtain sea-surface flow information from satellite scatterometer winds\ulcorner

  • Park, Kyung-Ae;Cornillon, Peter;Chung, Jong-Yul;Kim, Kuh
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.621-626
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    • 2002
  • A satellite scatterometer is a microwave radar sensor used to measure the backscattering at a sea surface. This instrument transmits radar pulses to the sea surface and measure the radar energy reflected back towards the source. Changes in wind velocity make sea surface roughness change and then affect on backscattered power. This gives us information of sea surface wind speed. Directions of wind vectors are acquired by multiple, collocated, and nearly simultaneous measurements. It should be noted that the scatterometer observes not the wind directly but the wind stress vector relative to the surface current. This suggests the possibility that the satellite scatterometer winds can include the effect of the surface current. This study shows the evidence that scatterometer measure surface wind stress, not surface winds and presents the velocity structure of oceanic warm and cold eddies.

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The Ground Checkout Test of OSMI(Ocean Scanning Multispectral Imager) on KOMPSAT-1

  • Yong, Sang-Soon;Shim, Hyung-Sik;Heo, Haeng-Pal;Cho, Young-Min;Oh, Kyoung-Hwan;Woo, Sun-Hee;Paik, Hong-Yul
    • Proceedings of the KSRS Conference
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    • 1999.11a
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    • pp.375-380
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    • 1999
  • Ocean Scanning Multispectral Imager (OSMI) is a payload on the KOMPSAT satellite to perform worldwide 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 800 km 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 and instrument aliveness/functional test as well, such as launch environment, on-orbit environment (Thermal/vacuum) and EMl/EMC test were performed at KARI. 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 in the late 1999 and the image is scheduled to start collecting ocean color data in the early 2000 upon completion of on-orbit instrument checkout.

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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.

Current Status of Antarctic Environments and Resources

  • Park, Paul-Kilho;Sutton, Holly J.;Kim, Su-Am
    • Journal of the korean society of oceanography
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    • v.33 no.3
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    • pp.123-135
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    • 1998
  • Cooperative scientific research in Antarctic has been successful since the International Geophysical Year 1957/1958. Presently, 43 nations have joined the Antarctic Treaty as consultative parties or acceding states, and other treaties and agreements have evolved to conserve the integrity and to manage the resources of the Antarctic ecosystem. Although yet to be designated, tourism areas in Antarctica are under consideration. Due to its remoteness and vast magnitude, Antarctica's science is slowly emerging. Satellite technology has enabled observation of the progression of the ozone hole above Antarctica. Mineral exploitation has yet to take place, as has the transport of Antarctic icebergs to some arid nations. On the other hand, both seal and whale exploitations have occurred, devastating these populations. The lessons learned from past human greed are used to design krill and squid fisheries, though the life histories of these organisms are yet to be adequately understood. An ecosystem approach to managing Antarctic resource exploitation is essential. Procuring the needed logistics to do so is daunting, requiring the highest degree of international cooperation and educational outreach to nurture the needed effective scientific and engineering talent, both natural and social.

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Estimation of Coastal Suspended Sediment Concentration using Satellite Data and Oceanic In-Situ Measurements

  • Lee, Min-Sun;Park, Kyung-Ae;Chung, Jong-Yul;Ahn, Yu-Hwan;Moon, Jeong-Eun
    • Korean Journal of Remote Sensing
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    • v.27 no.6
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    • pp.677-692
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    • 2011
  • Suspended sediment is an important oceanic variable for monitoring changes in coastal environment related to physical and biogeochemical processes. In order to estimate suspended sediment concentration (SSC) from satellite data, we derived SSC coefficients by fitting satellite remote sensing reflectances to in-situ suspended sediment measurements. To collect in-situ suspended sediment, we conducted ship cruises at 16 different locations three times for the periods of Sep.-November 2009 and Jul. 2010 at the passing time of Landsat $ETM_+$. Satellite data and in-situ data measured by spectroradiometers were converted to remote sensing reflectances ($R_{rs}$). Statistical approaches proved that the exponential formula using a single band of $R_{rs}$(565) was the most appropriate equation for the estimation of SSC in this study. Satellite suspended sediment using the newly-derived coefficients showed a good agreement with insitu suspended sediment with an Root Mean Square (RMS) error of 1-3 g/$m^3$. Satellite-observed SSCs tended to be overestimated at shallow depths due to bottom reflection presumably. This implies that the satellite-based SSCs should be carefully understood at the shallow coastal regions. Nevertheless, the satellite-derived SSCs based on the derived SSC coefficients, for the most cases, reasonably coincided with the pattern of in-situ suspended sediment measurements in the study region.

Usage of Internet-based Oceanographic GIS of the NW Pacific for Joint Analysis of Satellite and sub-Satellite Data

  • Golik A.V.;Fischenko V.K.;Dubina V.A.;Mitnik L.M.
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.371-374
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    • 2004
  • The task of development and usage in a corporate computer network of the Far Eastern Branch of the Russian Academy of Sciences (FEB RAS) of integrated technology of joint use by the scientists of satellite and sub satellite data on a Northwestern Pacific is considered. This integrated technology is realized by embedding of satellite data in the corporate oceanographic GIS of FEB RAS as a new information layer, and also by support of GIS by program techniques for specialized processing of both kinds of the data. As a result of integration the specialists of FEB RAS have an opportunity to carry out coordinated samples of satellite and various oceanographic data as a function of area, time and other important conditions, visualize them together and carry out analytical processing with the usage of the GIS tools. Application of the realized approach to improve the techniques of detection and description of the oceanic phenomena on ERS-l and ERS-2 SAR images as well as to improve of perspective techniques of the usage the brightness temperatures measured by a microwave radiometers AMSR-E on a board of Aqua (USA) satellites are discussed.

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Status and Prospects of Marine Wind Observations from Geostationary and Polar-Orbiting Satellites for Tropical Cyclone Studies

  • Nam, SungHyun;Park, Kyung-Ae
    • Journal of the Korean earth science society
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    • v.39 no.4
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    • pp.305-316
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    • 2018
  • Satellite-derived sea surface winds (SSWs) and atmospheric motion vectors (AMVs) over the global ocean, particularly including the areas in and around tropical cyclones (TCs), have been provided in a real-time and continuous manner. More and better information is now derived from technologically improved multiple satellite missions and wind retrieving techniques. The status and prospects of key SSW products retrieved from scatterometers, passive microwave radiometers, synthetic aperture radar, and altimeters as well as AMVs derived by tracking features from multiple geostationary satellites are reviewed here. The quality and error characteristics, limitations, and challenges of satellite wind observations described in the literature, which need to be carefully considered to apply the observations for both operational and scientific uses, i.e., assimilation in numerical weather forecasting, are also described. Additionally, on-going efforts toward merging them, particularly for monitoring three-dimensional TC wind fields in a real-time and continuous manner and for providing global profiles of high-quality wind observations with the new mission are introduced. Future research is recommended to develop plans for providing more and better SSW and AMV products in a real-time and continuous manner from existing and new missions.

Dynamics Modeling and Simulation of Korean Communication, Ocean, and Meteorology Satellite

  • No, Tae-Soo;Lee, Sang-Uk;Kim, Sung-Ju
    • International Journal of Aeronautical and Space Sciences
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    • v.8 no.2
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    • pp.89-97
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    • 2007
  • COMS(Communication, Oceanography, and Meteorology Satellite) is the first Korean multi-purpose satellite which is planned to be deployed at the altitude of geosynchronous orbit above the Korean peninsular. Noting that COMS is composed of the main BUS structure, two deployable solar panels, one yoke, five reactions wheels, COMS is treated as a collection of 9 bodies and its nonlinear equations of motion are obtained using the multi-body dynamics approach. Also, a computer program is developed to analyze the COMS motion during the various mission phase. Quite often, the equations of motion have to be derived repeatedly to reflect the fact that the spacecraft dynamics change as its configuration, and therefore its degree of freedom varies. However, the equations of motion and simulation software presented in this paper are general enough to represent the COMS dynamics of various configurations with a minimum change in input files. There is no need to derive the equations of motion repeatedly. To show the capability of the simulation program, the spacecraft motion during the solar array partial and full deployment has been simulated and the results are summarized in this paper.

Satellite data analysis of the China Coastal Waters in the Seas surrounding Jeju Island, Korea

  • Cho, Han-Keun;Kang, Heung-Soon;Kim, Jung-Chang;Yoon, Hong-Joo
    • Korean Journal of Remote Sensing
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    • v.22 no.5
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    • pp.397-402
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    • 2006
  • China Coastal Water (CCW) usually appears in the seas surrounding Jeju Island annually (June-October) and is very pronounced in August. The power spectrum density (PSD), sea level anomalies (SLAs), and sea surface temperatures (SSTs) were found to peak annually and semiannually. The peaks at intervals of 80-, 60-, and 43-days are considered to be influenced by CCW and the Kuroshio Current. Generally, low-salinity water appears to the west of Jeju Island from June through October and gradually propagates to the east, where CCW meets the Tsushima Current. Empirical orthogonal function (EOF) analysis of SLAs and SSTs indicated that the variance in SLAs and SSTs was 55.70 and 98.09% in the first mode, respectively. The PSD for the first mode of EOF analysis of SLAs was stronger in the western than in the eastern waters because of the influence of CCW. The PSD for the EOF analysis of SSTs was similar in all areas (the Yangtze Estuary and the waters to the west and east of Jeju Island), with a period of approximately 260 days.