台灣地區TOPSAR高程數據之研究

On the DEM Acquired by NASA/ JPL TOPSAR

干涉合成孔徑雷達系統（Interferometric Synthetic Aperture Radar, InSAR）擁有穿透雲霧與夜間作業的特性，可有效與以光學技術產製高程數據之作業方式互補，成為獲取大範圍數值高程數據的有利工具之一。本文簡介干涉合成孔徑雷達原理，敘述2000年美國NASA/JPL的『環太平洋全偏極合成孔徑雷達計畫』中於台灣觀測的TOPSAR數據，並對此一數值高程模型數據進行初步整體分析。雖然目前台灣地區已有較高精度與較高空間解析度之數值高程模型，但是TOPSAR為完全免費、「自由」之數據，而且其產製方式與目前產製之主要方式如空載光達或航空攝影測量原理不同。對學術探討，有重要之意義。 InSAR (Interferometric Synthetic Aperture Radar, InSAR) technology takes advantagesof cloud penetrating capability of microwaves, being claimed as a system for all weather andday and night. It is useful in producing DEM (Digital Elevation Model) on the area whereoptical method is hard to be applied. In this paper, the principle of InSAR is introduced.Then the TOPSAR DEM data of Taiwan area surveyed in NASA/JPL PacRIM-II mission wasalso introduced and analyzed in a preliminary way. Although there are DEM products ofTaiwan area with better accuracy or resolution, TOPSAR DEM is completely free, both in thesense of cost and legal restriction, and available through internet. Aside from above, it issignificant in academic sense for studying the DEMs produced from INSAR technology, which is different from the primary methods such as photogrammetry or LiDAR.

InSAR (Interferometric Synthetic Aperture Radar, InSAR) technology takes advantagesof cloud penetrating capability of microwaves, being claimed as a system for all weather andday and night. It is useful in producing DEM (Digital Elevation Model) on the area whereoptical method is hard to be applied. In this paper, the principle of InSAR is introduced.Then the TOPSAR DEM data of Taiwan area surveyed in NASA/JPL PacRIM-II mission wasalso introduced and analyzed in a preliminary way. Although there are DEM products ofTaiwan area with better accuracy or resolution, TOPSAR DEM is completely free, both in thesense of cost and legal restriction, and available through internet. Aside from above, it issignificant in academic sense for studying the DEMs produced from INSAR technology,which is different from the primary methods such as photogrammetry or LiDAR.