三颗高分辨率星载SAR的定位模型构建及其定位精度评价

Constructing Geo-location Models and their Geo-location Accuracy Evaluation of Three High Resolution Satellite SAR

随着TerraSAR-X,Cosmo-SkyMed和Radarsat-2这三颗高分辨率SAR卫星的成功发射,国内越来越多的用户开始通过商业渠道或通过参与SAR数据的应用示范项目免费获取到这三颗卫星的SAR数据。要很好地应用SAR数据必须首先解决其地理编码或几何校正问题,而该问题的核心是解决SAR定位模型的建立和解算方法,在此基础上就可以实现SAR影像的地球椭球校正地理编码(Geocoding of Ellipsoid Correction,GEC)处理,增强地球椭球地理编码(Enhanced Elliposid Correction,EEC)和地形校正地理编码(Geocoding of Terrain Correc-tion,GTC)或正射校正。本文研究并实现了这三颗高分辨率SAR数据的定位模型构建方法,并对GEC效果进行了评价。结果表明本文发展的定位模型构建方法是正确的,为实现这三颗高分辨率卫星SAR数据的EEC和GTC处理奠定了基础。

With successful launch of the three high resolution SAR satellites： TerraSAR-X,CosmoSkyMed and Radarsat-2,more and more people in China are using or going to acquire the three satellite data through commercial channel or scientific demonstration projects gratis.The geocoding or geometric correction problems of SAR image should be solved before applying SAR data to any applications.The key point to solve this problem is to establish the geo-location model of each SAR satellite or its data products.Based on the geo-location model,the geocoding program of ellipsoid correction（GEC）,enhanced ellipsoid geogoding（EEC）and geocoding of terrain correction（GTC）or ortho-rectification of SAR image can be easily implemented.The ways to construct geo-location models of these three SAR satellite data products have been studied,and the geo-location accuracy of GEC was evaluated.It shows that the geo-location model developed for each of the three SAR satellites is right and can provide fundamental support for the EEC and ortho-rectification of these space-borne SAR data.