運用衛星雷達干涉測量法在臺灣地區求定數值高程模型之初步實驗成果和實務探討

Preliminary Test Results and Practical Considerations on DEM Generation in Taiwan by Satellite SAR Interferometry

蔡展榮(Jaan-Rong Tsay) ； 陳鴻緒(Hung-Hsu Chen)

《航測及遙測學刊》 7卷1期 (2002/03) Pp. 15-34

https://doi.org/10.6574/JPRS.2002.7(1).2

摘要

本文使用商用軟體Vexcel 3dSAR的合成孔徑雷達資料處理系統FOCUS/PHASE與ERS Tandem Mode衛星雷達資料，以合成孔徑雷達干涉測量法（InSAR）求定實驗區（臺北縣都會區）的數值高程模型（DEM），說明和分析採用的衛星雷達資料處理計算步驟，並做一實務探討。將初步實驗產生之DEM與台北縣航測高精度參考DEM進行比較，共使用84個地面控制點，求得它們的平均高程差為-0.11公尺，均方差為4.71公尺。並取得約12km x 10km區域內共93850個共同格點，得兩者的高程差之均方根值（RMS）為23.73公尺，其中有86%之高程格點其高程差在±20公尺內；將高程差在±20公尺內之點位分佈與航測正射影像對照，可發現高程差與地表覆蓋物種類有著相關性：在建物密集的區域其高程差較大，約5至20公尺，而在無建物或無植被或稀疏植被覆蓋之區域其高程差較小，約在±5公尺之間。

關鍵字

衛星 ； 合成孔徑雷達 ； 干涉測量法 ； 數值高程模型

並列摘要

In this paper, we describe and study the SAR (=synthetic aperture radar) processing steps adopted in our preliminary tests for generating a digital elevation model (DEM) in Taiwan by means of satellite SAR interferometry. We used two modules FOCUS and PHASE of the commercial software system ”Vexcel 3dSAR Processing System” and ERS Tandem mode data to generate a DEM by the interferometric synthetic aperture radar (InSAR) approach. The generated DEM is compared with the high precision reference DEM determined by aerial photogrammetry with an average flight height of about 1600m in the same area of about 42km x 25km in Taipei. Altogether 84 ground control points are adopted. They show a mean and RMS(=root mean square) value of height differences of -0.11m and 4.71m, respectively. Moreover, there are altogether 93850 common height points in an area of about 12km x 10km. They indicate a RMS value of height differences of 23.73 meter. About 86% of all these points has the absolute height difference |dH| ＜20m. Comparing the distribution of these points with the aerial ortho image shows the correlation between the height difference and the land cover type. The absolute height difference is larger in the area of dense buildings, about 5-20 meter. In the near bare area of no buildings and less vegetation, the absolute height difference is smaller and less than 5 meter.

並列關鍵字

Satellite ； Synthetic Aperture Radar (SAR) ； Interferometry ； Digital Elevation Model (DEM)