摘要: | 隨著國際間的多顆X波段衛星雷達發射運作後,解析度達到5~3公尺,且重複軌道觀測週期的縮短,也就是時間解析度的提升。在干涉雷達應用上降低過去在觀測上常見的時間去相關(temporal decorrelation)。如德國TerraSAR-X衛星為11天週期,義大利COSMO-SkyMed星座衛星的4顆同規格雷達系統拍攝更可提高到1週3次重複軌道觀測。本研究是以高雄市阿蓮與岡山區為研究區,使用德國TerraSAR-X與義大利COSMO-SkyMed衛星影像資料,採用升模與降模雙模式觀測方式,結合不同觀測角度不同方向軌道進行地表三維地變形分解,降低差分干涉雷達觀測上的水平和垂直方向模糊問題。由於X波段資料易受到大氣影響使訊號衰減,在影像對選取時,除基線條件外,需考慮影像拍攝當時的天氣狀況,使用雷達回波圖,將水氣影響的影像先予以剔除,避免水氣造成相位偏移影響後續地變形量分解的誤差。經過昇模與降模式觀測顯示在高鐵阿蓮段附近,於2011年1-5月約有3公分下陷量,並且在岡山市區靠近岡山交流道附近有工廠小區域的地變形,三維分解結果2011年8-11月約有0.6公分的下陷率;經過2011年8月現地調查發現在阿蓮、岡山區域確實有路面破裂,圍牆傾斜等現象。本研究首次應用X波段雙模式差分干涉雷達於台灣地區進行小區域地變形觀測與成果驗証,展示干涉雷達遙測在高度開發的都會型地變形觀測應用。Currently several X-band satellite radar have been in orbit. As the spatial resolution up to 3 to 5 meters with shorter revisit time, meaning also the improvement of time resolution, it becomes more effective to apply the radar interferometry because the temporal decorrelation may be reduced. For example, the German TerraSAR-X satellite has 11 days cycle, and the four Italian COSMO-SkyMed constellation of satellites increase up to three times orbiting observation of repeated cycle in just one week..This thesis uses the German TerraSAR-X and the Italian COSMO-SkyMed satellite image data to perform interferometric observation of subsidence prone areas of Alian and Gangshan districts in Kaohsiung. By integrating both ascending and descending observations at different observation angles and different directions, ground deformation decomposition is carried out to estimate the three dimensional surface displacement while reducing the ambiguity in the horizontal and vertical direction for the differential interferometry radar observations. Since X-band radar image may be influenced by the atmospheric screen effect, it is essential not only to consider baseline requirement, the phase shift due to atmospheric delay must be taken into account as well. From the ascending and descending observations, results reveal about 3 cm of subsidence near the Alian area during January-May 2011 and subsidence about 0.6 cm in factory region near in the Intersection of Gangshan area during August- November 2011. Through the ground truth survey in Aug. 2011, it is found that road surface rupture and the wall tilt occurred in Alian and Gangshan area.For the first time in Taiwan, this study applies X-band dual-mode differential interferometry radar to observe three dimensional ground deformation in small area and demonstrates the applications of radar interferometry for surface subsidence mapping in metropolitan area. |