Study of Effect of Raw Data Compression on Space-borne SAR/GMTI Velocity Measurement
原始数据压缩对星载SAR/GMTI系统测速影响研究

At present, the effective way to resolve the contradiction between huge space-borne SAR raw data rate and limited on-board data-transmission bandwidth is space-borne SAR raw data compression. The higher compression ratio is, the lower data rate will be, but larger quantization error will affect the velocity measurement accuracy of SAR-GMTI. The lower compression ratio is, the less effect of data compression on velocity measurement accuracy is, but the higher data rate will be. Therefore, the choice of data compression ratio needs achieve a compromise between data rate and velocity measurement accuracy. This paper establishes the echo simulation model of space-borne SAR/GMTI system and simulates the raw data of space-borne SAR-GMTI. For Displaced Phase Center Antenna (DPCA) and Along-Track Interferometry (ATI) methods which have significant application potentialities in practice, this paper analyzes the effect of Block Adaptive Quantization (BAQ) algorithm on velocity measurement accuracy in detail. The results of this paper provides important theory basis for the choice of compression ratio of the space-borne SAR/GMTI system.