Study On Target Positioning Techniques Based On Airborne SAR

With airborne SAR imagery the technique of geolocation can absolutely locate the groundtargets without any reference point on the ground. So it is an available technique in civil and militaryaffairs. This paper studies the technique of SAR imagery geolocation. With the technique we can getthe information of longitude and latitude without any reference point on the ground. Imagingalgorithm, coordinate transformation and geolocation method of the technique are studied in greatdetail. A new approach based on Sum and difference beams has been developed to determine thelocations of the ground targets without reference point. The main content of the paper is summarizedas follows:In chapter1, we introduce the history and latest developments of geolocation. And its principleand theories are presented.In chapter2, LRD imaging algorithm used by airborne SAR is analyzed in great detail in thepaper. The implementation steps of LRD are presented. And the validity of the algorithm is tested bysimulation experiments.In chapter3, the coordinates used by airborne SAR geolocation are analyzed in the paper. Themethods and implementation steps of coordinate transformation are presented. And the validities ofthe methods are tested by simulation experiments.In chapter4, the principles of Range Doppler geolocation method are analyzed. And theimplementation steps of Range Doppler geolocation method are presented. The validity of the methodis tested by simulation and processing of real measure SAR data. The influence of inaccurateparameters on the accuracy of geolocation is also investigated.In chapter5, a new approach based on Sum and difference beams has been developed todetermine the locations of the ground targets without reference point. The principles andimplementation steps of the method are presented. And the influence of inaccurate parameters on themethod is also investigated.In chapter6, the Sum and difference beams method is compared with the Range Doppler one.The influences of inaccurate parameters on both methods are compared. The thesis is summarized.And some problems which require further investigation are pointed out.