王錫祺《台灣海域JASON-1測高衛星的絕對率定與成果》
中正大學應用地震研究所
96學年度第2學期 2008/07
近年來衛星測高儀(satellite altimetry)已經發展成為一成熟的海洋資料收集工具，但是其資料還未能完全用於全球絕對海水面研究上，因為衛星測高儀觀測量與實際海水高度存在有一固定偏差(bias)，大小約為數公分，但目前公認的全球海水面上升趨勢的大小約為每年1至2 公釐左右，而海水面的量測會影響大地水準面的訂定，為滿足海水面監測與大地水準面訂定相關研究之需求，因此必須借助其他獨立的資料收集工具，例如：全球定位系統(Global Positioning System, GPS)浮標(buoys)、潮位站(tide gauges)等，率定衛星測高儀所測之海面橢球高(sea surface height, ssh)。本研究根據衛星軌道位置、走向，選定台南安平附近建立JASON-1 測高衛星之率定站，以GPS 浮標測量海面橢球高，並與JASON-1 觀測量進行測高儀Ku 頻的海水面橢球高作直接比對。推求出2008/03/17 安平外海JASON-1 測高衛星的固定偏差為13.4± 5.6cm 。間接率定推求P2 及P3 的固定偏差分別為18.1±1.9cm 與9.6± 1.9cm，與全球其他固定式率定站的值接近。後續研究可以討論ENVISAT、JASON-2 或延續潮位及測高儀資料與全球平均海水面的研究等。
Satellite altimetry has become an efficient tool for data collection over oceans. However, there is a bias between the sea surface height (ssh) observation of satellite altimeters and the actual sea level. Hence, the ssh observation may not be directly adopted by the studies of global sea level rise with the magnitude of 1–2 mm/year without precise calibration. Absolute calibration of satellite altimetry requires the ssh to be measured by an independent tools, such as Global Positioning System (GPS) buoys and tide gauges. In this study, we analyzed groundtrack location and the satellite's moving direction of JASON-1 altimeter and selected Anping, Tainan as the candidate site for calibration. A GPS buoy campaign near Anping has been conducted in order to catch the directly Ku overflight of JASON-1 space vehicle . The result of directly overflight show the bias is about 13.4 ± 5.6cm on July 23, 2007. The result of indirect overflight show the bias is about 14.1 ± 1.4cm. The value stands which with the global other stationary type calibration approaches. The following research may discuss ENVISAT, JASON-2 or continues the tide and the satellite altimetry material and the global mean sea level research and so on.
96學年度第2學期 2008/07
近年來衛星測高儀(satellite altimetry)已經發展成為一成熟的海洋資料收集工具，但是其資料還未能完全用於全球絕對海水面研究上，因為衛星測高儀觀測量與實際海水高度存在有一固定偏差(bias)，大小約為數公分，但目前公認的全球海水面上升趨勢的大小約為每年1至2 公釐左右，而海水面的量測會影響大地水準面的訂定，為滿足海水面監測與大地水準面訂定相關研究之需求，因此必須借助其他獨立的資料收集工具，例如：全球定位系統(Global Positioning System, GPS)浮標(buoys)、潮位站(tide gauges)等，率定衛星測高儀所測之海面橢球高(sea surface height, ssh)。本研究根據衛星軌道位置、走向，選定台南安平附近建立JASON-1 測高衛星之率定站，以GPS 浮標測量海面橢球高，並與JASON-1 觀測量進行測高儀Ku 頻的海水面橢球高作直接比對。推求出2008/03/17 安平外海JASON-1 測高衛星的固定偏差為13.4± 5.6cm 。間接率定推求P2 及P3 的固定偏差分別為18.1±1.9cm 與9.6± 1.9cm，與全球其他固定式率定站的值接近。後續研究可以討論ENVISAT、JASON-2 或延續潮位及測高儀資料與全球平均海水面的研究等。
Satellite altimetry has become an efficient tool for data collection over oceans. However, there is a bias between the sea surface height (ssh) observation of satellite altimeters and the actual sea level. Hence, the ssh observation may not be directly adopted by the studies of global sea level rise with the magnitude of 1–2 mm/year without precise calibration. Absolute calibration of satellite altimetry requires the ssh to be measured by an independent tools, such as Global Positioning System (GPS) buoys and tide gauges. In this study, we analyzed groundtrack location and the satellite's moving direction of JASON-1 altimeter and selected Anping, Tainan as the candidate site for calibration. A GPS buoy campaign near Anping has been conducted in order to catch the directly Ku overflight of JASON-1 space vehicle . The result of directly overflight show the bias is about 13.4 ± 5.6cm on July 23, 2007. The result of indirect overflight show the bias is about 14.1 ± 1.4cm. The value stands which with the global other stationary type calibration approaches. The following research may discuss ENVISAT, JASON-2 or continues the tide and the satellite altimetry material and the global mean sea level research and so on.
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