合成孔径雷达原始数据AP-TCQ压缩算法  

AP-TCQ Compression Algorithm for SAR Raw Data

作　　者：张文超[1] 王岩飞[1] 潘志刚[1] 

机构地区：[1]中国科学院电子学研究所

出　　处：《数据采集与处理》2008年第1期89-94,共6页Journal of Data Acquisition and Processing

摘　　要：研究了合成孔径雷达原始数据幅相压缩算法(Amplitude and Phase,AP)和网格编码量化(Trellis codedquantization,TCQ),提出了合成孔径雷达原始数据AP-TCQ压缩算法。将I,Q两路原始数据转化为极坐标下相同大小的幅度-相位数据,根据率失真不等式由拉格朗日乘子法推导了基于幅度微分熵和相位微分熵的最优比特分配公式,然后用对应的比特数分别进行幅度和相位的网格编码量化。文中还探讨了TCQ码书的构成对AP-TCQ压缩算法性能的影响,通过理论分析和实验结果比较指出:幅度数据采用瑞利分布Lloyd-Max码书进行TCQ量化(Rayleigh trellis coded quantization,RTCQ),相位数据采用均匀分布Lloyd-Max码书进行TCQ量化(Uniform trellis coded quantization,UTCQ),具有最佳的量化性能。与I,Q两路原始数据采用TCQ算法和已有的AP算法相比,该方法能够很好地保留原始数据的相位信息,且能够实现幅度相位压缩量化比特自动分配,具有更好的压缩性能。The amplitude and phase （AP） algorithm for raw data of synthetic aperture radar （SAR） and the trellis coded quantization（TCQ） are studied and the AP-TCQ compression algorithm is proposed. The raw data of I,Q channels are converted into the same amplitude and phase data in polar coordinates. The formula of optimal bit allocation for the amplitude and phase is deduced by the Lagrange multiplier based on the Rate-Distortion equality. The ampli- tude and phase data are quantized by TCQ at the desired bits allocated by their differential entropy, respectively. The effect of the TCQ codebook on the algorithm performance is also discussed. The conclusion can be drawn： amplitude data use the Lloyd-Max codebook of the Rayleigh distribution and phase data use the uniform distribution, thus having the best compression results. Compared TCQ algorithm for I,Q channels of raw data with the AP algorithm, the method can preserve the phase information better, automatically realize the bit allocation of the amplitude and the phase, and has better compression performance.

关 键 词：合成孔径雷达 原始数据压缩 比特分配 网格编码量化 AP算法 

分 类 号：TN958[电子电信—信号与信息处理]