空載干涉雷達系統高解析度數位高程模型精度評估

Accuracy Assessment of High Resolution Digital Elevation Model Derived from Airborne InSAR System

王志添(C. T. Wang) ； 陳錕山(K. S. Chen) ； 饒見有(J. Y. Rau) ； 施盈萱(Joy Shih) ； 陳哲俊(A. J. Chen)

《航測及遙測學刊》 10卷3期 (2005/09) Pp. 287-298

https://doi.org/10.6574/JPRS.2005.10(3).6

摘要

本文評估以空載雷達系統於台灣西南區域實施干涉雷達量測獲取高解析度雷達影像資料與數位高程資料之幾何精度。實驗區涵蓋嘉義、台南、高雄、屏東等縣市，約3676平方公里。資料經處理後得解析力為1.25公尺之正射化雷達影像及網格大小為5公尺之數位高程模型。經以內政部公佈基本控制測量成果資料之一、二等水準點資料共292點檢測干涉雷達量測高程後，發現其均方差為1.5公尺，系統偏差值為0.6公尺。誤差來源係因三角點高程為GPS樁位高程，雷達獲取高程為GPS樁位附近地表平均高程差異。經以水位深度模擬高屏溪口附近低漥地區，與2001年7月5日颱風後獲取之RADARSAT-1影像測得溢淹區域之成果與以上結論一致，說明此一高效率、高解析與高精度數位高程模型符合環境監測實務應用之需求。

關鍵字

干涉雷達 ； 數位高程模型

並列摘要

This paper presents accuracy assessment of InSAR derived DEM acquired by Intermap's IFSAR system. The flight area was located southwestern Taiwan covering counties of Chiayi, Tainan, Kaohsiung and Pingtung with about 3676 squared km mapping size. The output data included ortho-rectified radar image at 1.25 m resolution and digital elevation model at 5 meter posting. We compared the DEM with 292 ground control points provided by Satellite Survey Center, Department of Land Administration, MOI. It was found that the height difference standard deviation was around 1.5 m and the bias was 0.6 m. In this experiment campaign, the accuracy obtained from InSAR derived is highly acceptable for many applications. The error sources were attributed to the difference between the use of GPS point height and InSAR area (averaged over 5 squared meters) height. The relation of height difference to aspect and slope illustrated that there exist weak dependence of terrain effects. For purpose of demonstration, we overlaid the flooded area derived from RADARSAT-1 with DEM at fine and coarse resolution to illustrate the importance of high resolution DEM data in assessing the flood risk.

並列關鍵字

Interferometric SAR ； Digital Elevation Model