• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.70-75
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• 1998

The comparison of Topex/Poseidon sea surface heights and Tide Gauge sea levels was studied in the South Indian Ocean after Topex/Poseidon mission of about 3 years (11- 121 cycles) from January 1993 through December 1995. The user's handbook (AVISO) for sea surface height data process was used in this study Topex/Poseidon sea suface heights ($\zeta$$^{T/P}$), satellite data at the point which is very closed to Tide Gauge station, were chosen in the same latitude of Tide Gauge station. These data were re-sampled by a linear interpolation with the interval of about 10 days, and were filtered by the gaussian filter with a 60 day-window. Tide Gauge sea levels ($\zeta$$^{Argos}$, $\zeta$$^{In-situ}$ and $\zeta$$^{Model}$), were also treated with the same method as satellite data. The main conclusions obtained from the root-mean-square and correlation coefficient were as follows: 1) to Produce Tide Gauge sea levels from bottom pressure, in-situ data of METEO-FRANCE showed very good values against to the model data of ECMWF and 2) to compare Topex/Poseidon sea surface heights of Tide Gauge sea levels, the results of the open sea areas were better than those of the coast and island areas.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.3
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• pp.368-373
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• 1999

Topex/Poseidon sea surface heights are compared to tide gauge sea levels in the South Indian Ocean in the period of January 1993 to December 1995. A user's handbook (AVISO) for processing sea surface height data was used in this study. Topex/Poseidon sea surface heights were obtained from satellite data at the proximity of tide gauge stations. These data were reproduced by a linear interpolation with the interval of 10 days and were processed by the Gaussian filter with a 60-day window. The tide gauge sea levels were obtained in the same manner as the satellite data. The main results on RMS (Root-Mean-Square) and CORR (CORRelation coefficient) in our study were shown as follows: 1) on the characteristics between two data (in-situ and model data), the results (RMS=2.96 cm & CORR=$92\%$ in the Amsterdam plateau, and RMS=3.45 cm & CORR=$59\%$ in the Crozet plateau) of the comparison of Topex/Poseidon sea surface heights with tide gauge sea levels, which was calculated by in-situ data of obsewed station showed generally low values in RMS and high values in CORR against to the results (RMS=4.69 cm & CORR=$79\%$ in the Amsterdam plateau, and RMS= 6.29 cm & CORR= $49\%$ in the Crozet plateau) of the comparison of Topex/Poseidon sea surface heights with tide gauge sea levels, which was calculated by model data of ECMWF (European Center for Medium-range Weather Forecasting), and 2) on the characteristics between two areas (Kerguelen plateau and island), the results (RMS=3.28 cm & CORR= $54\%$ in the Kerguelen plateau) of open sea area showed low values in RMS and high values in CORR against to the results (RMS= 5.71 cm & CORR=$38\%$ in the Kerguelen island) of coast area, respectively.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.05a
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• pp.755-758
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• 2001

Topex/poseidon 위성의 자료를 통하여 남인도양의 암스테르담- 크호제트- 케르겔른 지역에 대한 표층 순환과 해수면 변화의 시ㆍ공간적인 해석을 쉽게 수행 할 수 있었다. 각 지역에서의 시ㆍ공간적인 변화 특성들을 보면, 암스테르담지역은 서쪽으로 전파하는 로쓰비파가 존재한다. 이때 이 파는 동쪽으로 전파하는 남극순환해류의 영향을 받는다. 1993년 늦가을에서 초겨울 동안에 분지의 동부지역에서 해수면이 급격히 떨어졌다. 이곳은 남극순환해류(아규라스순환반류전선과 아열대전선)의 북부에서 발전하는 시계방향(cyclonic)의 와동류가 예외적으로 강하게 북쪽으로 상승했다가 이어서 급격히 남쪽으로 하강했던 것과 관련된다. 쌩뽈지역은 5cm 정도의 해수면 진동과 함께 약 130일 정도의 주기성을 보였다. 서쪽으로 전파하는 신호인 자유 표면의 진동이 실제로 조사되었다.

• Proceedings of the KSEEG Conference
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• 2001.04a
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• pp.356-360
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• 2001

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 1998.06a
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• pp.382.2-383
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• 1998

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 1998.06a
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• pp.380.2-381
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• 1998

• Journal of the Korean earth science society
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• v.23 no.4
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• pp.349-356
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• 2002

In an effort to properly assess the validity of spaceborne radar altimeter measurements, we made a direct comparison of two different sea surface heights (SSH) acquired by both Topex/Poseidon (T/P) satellite and in-situ tide-gauges (T/G). This comparative analysis was conducted using the data sets collected from three locations along the eastern coast of Korea which include: Ulleungdo, Pohang, and Sokcho. In the course of the analysis of satellite altimeter, information of SSH was extracted from the T/P MGDR data sets through the application of both atmospheric and geophysical corrections. To compare the T/P data sets in parallel basis, the T/G data sets were averaged using the measured values within the peripheral radius of 55km. When compared among different locations, the compatibility between the two methods was much more significant in an offshore location (Ulleungdo) than the two onshore locations (Pohang, Sokcho). If the low-pass filtered results were compared among the sites, the offshore site exhibited the best correlations between the two methods (correlation coefficient of 0.91) than those of the onshore sites. These large differences in the strength of correlations among different locations are due to the deformation of M2, S2, and K1 tidal components used in the tidal model. In case of the offshore location, the compatibility of the two different methods were improved systematically by the low-pass filtering with an increase of the filtering duration such as up to 200 days.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2003.04a
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• pp.297-299
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• 2003

Altimeter(Topex/Poseidon) and AVHRR(NOAA) data were used to study the variations and correlations of Sea Level(SL) and Sea Surface Temperature (SST) in the North East Asian Seas from November 1993 to May 1998. This region is influenced simultaneously to continental and oceanic climate as the border of the East Sea(Japan Sea). SL and SST have increased gradually every year because the global warming, and presented usually a strong annual variations in Kuroshio extension region with the influence of bottom topography.

• Korean Journal of Remote Sensing
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• v.14 no.2
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• pp.117-128
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• 1998

Topex/Poseidon satellite, launched in Auguest 1992, has provided more 5 years of very good quality data. Efficient improvements, either about instrumental accuracy or about sea level data correction, have been made so that Topex/Poseidon has become presently a wonderful tool for many researchers. The first mission data of 73 cycles, September 1992 - August 1994, was used to our study in order to know characteristics of environmental correction factors in the Amsterdam-Crozet-Kerguelen region of the South Indian Ocean. According to standard procedures as defined under user handbook for sea surface height data processes, then we have chosen cycles 43 as the cycle of reference because this cycle has provided the completed data for measurement points and has presented the exacted position of ground track compared to another cycles. It was computed variations of various factors for correction in ascending ground track 103(Amsterdam-Kerguelen continental plateau) and descending ground track170 (Crozet basin). Here the variations of ionosphere, dry troposphere, humid troposphere, electromagnetic bias, elastic tide and loading tide were generally very smaller as a few of cm, but the variations of oceanic tide(30-35cm) and inverted barometer(15-30cm) were higher than another factors. For the correction of ocean tide, our model(CEFMO: Code d' Elements Finis pour la Maree Oceanique) - This is hydrodynamic model that is very well applicated in all oceanic situations - was used because this model has especially good solution in the coastal and island area as the open sea area. Conclusionally, it should be understood that the variation of ocean free surface is mainly under the influence of tides(>80-90%) in the Amsterdam - Crozet- Kerguelen region of the South Indian Ocean.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.6
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• pp.1190-1194
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• 2001

The first 7 years of altimeter data from the TOPEX/POSEIDON(T/P) were analyzed to study the surface circulation and its variability in the East Asian Marginal Seas. Long term averaged T/P sea level time series data where compared with in situ sea level measurements from a float-operated type tide gauge around of south Korea and Japan. T/]P data are a large contaminated by 60-day tidal aliasing effect, very near the alias periods of M2 and 52. When this 60-day effect is removed, the data agree well with the tide gauge data with 4.6 cm averaged RMS difference. The T/P derived sea level variability reveals clearly the well-known, strong current-topography such as Kuroshio. The T/P mean sea level of North Pacific(NP) was higher than Yellow Sea(YS) and East Sea(ES). The T/P sea level variability, with strong eddy and meandering, was the largest in eastern part of Japan and this variability was mainly due to the influence of bottom topography in Kuroshio Extension area.