无地面控制点的星载SAR影像直接对地定位研究
Location of Spaceborne SAR Imagery Without Reference Points
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摘要: 针对星载合成孔径雷达(SAR)对地面目标的定位问题,分析了在无地面控制点的情况下,利用距离-多普勒(R-D)模型和地球模型进行对地定位的理论与方法,给出了在无地面控制点(GCP)而有数字高程模型的情况下利用R-D模型进行对地定位的求解方法。用天津地区ERS-1数据进行实验,其结果与当地地形图进行比较,精度在50 m以内,表明该文提出的方法是正确、可行的。Abstract: A method is developed to determine the location of a pixel in a SAR image in this paper.This technique utilizes the spacecraft ephemeris data and the characteristics of the SAR data collection system to produce an estimate of the latitude and longitude of an arbitrary pixel.This approach has an advantage over previous techniques in that it requires no reference points and is independent of spacecraft attitude knowledge or control.Test is conducted using ERS1 SAR imagery,comparing predicted feature location with the location as determined by high precision area maps.Results indicate an accuracy of 50 m is attainable with this method.