應用高空間與高時間分辨率之福爾摩沙二號衛星遙測影像探討極區冰架崩解之機制 (I)

• Main Author: 劉正千
• Other Authors: 地球科學系
• Format: Report
• Language: Chinese; English
• Published: 2009
• Subjects: 極區; 冰架; 追蹤浮冰; 崩解; 遙測; Polar Regions; ice shelves; tracking floating ice; disintegration; remote sensing; Formosat-2; Amundsen Scott South Pole Station; Amundsen-Scott; Amundsen-Scott South Pole Station; Greenland; South Pole; Wilkins; Wilkins Ice Shelf; Ice Shelf; Ice Shelves; International Polar Year; National Snow and Ice Data Center; South pole; Upernavik
• Online Access: http://ir.lib.ncku.edu.tw/handle/987654321/139126; http://ir.lib.ncku.edu.tw/bitstream/987654321/139126/1/應用高空間與高時間分辨率之福爾摩沙二號衛星遙測影像探討極區冰架崩解之機制 (I).pdf

計畫編號:NSC98-2116-M006-012 執行機構:國立成功大學地球科學系（所） 研究期間:2009-08~2010-07 國際極區年(International Polar Year 2007-2008)的主要任務之一，是協調並蒐集衛星在劇烈變化的極區環境中所獲取之各種資料。然而受到高度、刈幅、以及指向能力的限制，高空間分辨率光學遙測衛星的操作仍侷限於一定的緯度範圍。由台灣的國家太空中心所操控的福爾摩沙二號衛星（福衛二號）是全世界第一枚運行在每日再訪軌道上的高空間分辨率光學遙測衛星。福衛二號搭載了雙軸高扭矩反應輪，可以分別在沿軌±450 與跨軌±450 的兩個方向上進行指向拍攝。此特性讓我們每天都可以獲取極區任何地方2 公尺解析度的光學影像。我們已經成功地展現了這些前所未有的福衛二號影像是極區研究非常寶貴而重要的資料來源，例如全世界第一幅南極科學站的高空間分辨率光學衛星影像，以及在最近南極威爾金冰架崩解事件中所揭露的許多詳細資訊。 本研究與美國冰雪資料中心(National Snow and Ice Data Center; NSIDC)合作，運用高空間與高時間分辨率的福衛二號影像，共同探討極區冰架崩解事件的機制。研究的目標區域是格陵蘭三大冰川Upernavik ， Helheim 和Kangerdlugssuaq 的出海口附近。這些地區的福衛二號level-2 影像由國家太空中心提供，更高階的產品則由福衛二號影像自動處理系統產製。為確保詳細的速度與渦度場可以由前後期的影像中推導出來，本研究發展了一個可以同時考慮冰塊旋轉與平移效應的影像自動匹配模組。我們與NSIDC 的首席科學家Dr.Ted Scambos 密切合作，共同分析所有的福衛二號影像。本研究的最終目的是運用高空間與高時間分辨率的福衛二號影像，建立極區冰架崩解發生的機制。 Coordinating and collecting satellite data of changing polar environments is one of the prime activities occurring during International Polar Year 2007-2008. Limited to their altitude, swath and pointing capability, however, the operation of optical satellites with high-spatial-resolution sensors is generally restricted to certain latitudes. Operated by the National Space Organization of Taiwan, Formosat-2 is the first satellite with a high-spatial-resolution sensor placed in a daily revisit orbit. Equipped with two-axes high torque reaction wheels, Formosat-2 is able to point not only to �450 across track, but also to �450 along track. This characteristic enables us to acquire the optical imagery with 2m resolution at any place in Polar Regions everyday. We have demonstrated that these unprecedented images are a very useful data source with immediate impact on the research of Polar Regions, such as the first space-borne high-spatial-resolution (2m) optical image of the Amundsen-Scott South Pole Station, and the details of recent Wilkins Ice Shelf disintegration event. This research collaborates with the National Snow and Ice Data Center (NSIDC) to investigate the mechanism of ice shelf disintegration in Polar Regions using Formosat-2 high-spatial- and high-temporal-resolution imagery. The target areas of this research are the outlets of three glaciers in Greenland, namely Upernavik, Helheim, and Kangerdlugssuaq. The level-2 images of Polar Regions were produced by NSPO, and then the automatic Formosat-2 image processing system (F2-AIPS) were employed to produce the higher level products. To ensure the detailed velocity field and the vorticity field can be accurately mapped from the before- and after-event image pairs, we develop an automatic image coregistration module that is able to consider both the rotation and translation of ice floes. We work closely with the Chief Scientist, Dr. Ted Scambos, in NSIDC to analyze all Formosat-2 images. The ultimate goal is to come up with a detailed mechanism of ice shelf disintegration in Polar Regions using Formosat-2 high-spatial- and high-temporal-resolution imagery.