| How to determine location of target is very important in the application of remote sensing imagery. Location of target is an basic information in remote sensing imagery. It is fundamental for topographic survey, disaster monitoring, resource survey, change detection and so on. How to determine precise location and acquire 3D information by remote sensing is a focus in the remote sensing community. Synthetic Aperture Radar (SAR) is a hot point of research because SAR can observe all-weather and all day, and penetrate some object. Interferometric Synthetic Aperture Radar (InSAR) develops from SAR. Carried forward the merit of SAR, InSAR can acquire high precise DEM or accomplish change detection, such as slow-moving targets or subtle shift of the earth's surface. InSAR is widely applicated in many areas, such as military, civil and scientific research, which make InSAR one of the most active fields in Radar and Remote Sensing nowadays.There are two methods of how to determine location of points in SAR imagery. First method: This method looks for some feature points whose precise location, then finish location of points in SAR imagery by deduce relative position of image pixel and the control points. Second method: Its model was first proposed by Curlander J.C in 1982. Tests were conducted using SEASAT SAR imagery, comparing predicted feature location with the location as determined by high precision area maps. Results indicate that location accuracy of 200 meters is attainable with this model. But he didn't explain how to resolve the model in practical application. The method has two merits: 1) It needn't determine location pixel in SAR imagery. The method will make a break in the theory of earth-space location; achieve space-space location (absolute location). 2) Accuracy of location will only be determined by precise of satellite ephemeris, earth model, precise of range by determined pulse delay, estimation of Doppler frequency. So we must study SAR imaging feature for implement location of SAR imagery with no ground control point. The test results are also promising.The concept of InSAR was first proposed by L. C. Graham in 1974. Because of its severe requirement on the raw data pair, no distinct progress was made in about ten years that followed. It is the huge amount of raw data achieved by various spacebome SAR systems (ERS, Radarsat,JERS) after 1990's, which satisfy the request that make research on InSAR technique a focus in the remote sensing.In the paper, the location of target from SAR imagery is implemented without GCP and factors that effect position accuracy are analyzed. How to acquire precise DEM from InSAR is also studied in this paper. Main aspects of the paper include principle of SAR imaging, SAR imaging how to influence location of spaceborne SAR, model of location, principle of InSAR, implement chart of InSAR data processing, key principle and the fulfilling of each links of the procedure. Special stress is laid on the illustration to make basic concept and principles accurate, clear and easy to understand. After analyzing traditional algorithm, how to improve accurate of subpixel register, flat-earth remove, phase unwrapping and phase transfer to height is brought forward. Results indicate that algorithm and model is reasonable. Arrangement of chapters and sections are as follows:Chapter One presents development and current state of SAR, bring forward main research contents.Chapter Two discuss basic principle and primary working of spaceborne SAR.Chapter Three analyses geometry of SAR, motion compensation of SAR, and algorithm for spaceborne SAR imaging, implement RD algorithm.Chapter Four discusses principle of location of spaceborne SAR, describes the relation between imaging parameter and location of object. Implement simulation of point object and acquire an important conclusion. Final tests were conducted using real data.Chapter Five presents basic principle of InSAR, introduce algorithm for estimate baseline. Primary factors which influence the accuracy of DEM obtained f...
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