Location of Spaceborne Sar Imagery

Abstract

A method has been developed to determine the location of a pixel in a digital SAR image. 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. Tests were conducted using SEASAT SAR imagery, comparing predicted feature location with the location as determined by high precision area maps. Results indicate an accuracy of 200 m is attainable with this method. Error sources are analyzed and recommendations are given to improve image location accuracy in future spaceborne SAR's.