Echo Simulation And Imaging Study Of Spaceborne Scansar

Synthetic Aperture Radar (SAR) is a kind of active microwave imaging radar, which utilizes the method of aperture synthesis to achieve high resolution in the azimuth direction. The scanning mode SAR (ScanSAR) can get very large observation swath width, which makes it possible for monitoring of large area. In this paper, the methods for ScanSAR echo simulation, imaging and combining are studied.First, two echo simulation methods are discussed, that is the range frequency domain method and the two-dimensional frequency domain method. In the part of imaging and combining, several commonly used imaging algorithms are studied, including the Range Doppler Algorithm, Chirp Scaling Algorithm, SPECAN Algorithm and the modified SPECAN Algorithm. Based on the analysis of the results of these algorithms, subimages are combined together with some combining methods. The azimuth pixel spacing of different algorithms are discussed in detail, which is the reason for mismatch in azimuth direction. Based on the modified SPECAN method, a method to normalize the pixel spacing is given so to generate a fine combination. Finally, the problem of SAR raw data compression is also studied. Considering the methods of BAQ and VQ, some compression methods are studied and compared. All algorithms studied in this paper, including echo simulation, several imaging algorithms, subimage combining and data compression, are implemented in VC...