用于HJ-1-C卫星ScanSAR的等效RD几何校正方法

Geo-correction Algorithm Based on Equivalent RD Model for ScanSAR of HJ-1-C Satellite

HJ-1-C卫星是我国第1颗民用合成孔径雷达卫星,具有条带和扫描两种工作模式。该文根据HJ-1-C卫星ScanSAR模式的工作特点,在ECS成像算法和传统斜距多普勒定位方法基础上,提出一种适用于ScanSAR的等效RD几何校正方法。首先根据方位时刻关系进行方位拼接,然后根据斜距关系拼接各个子带,接着拟合等效参数,进行斜距多普勒定位,最后实现ScanSAR图像的几何校正。HJ-1-C卫星的实际数据实验结果表明:HJ-1-C卫星ScanSAR模式的定位精度可以达到100 m;24核CPU并行情况下实现10 s处理完一景图像。

HJ-1-C satellite is the first Synthetic Aperture Radar （SAR） satellite for civilian use in China, and it has a strip and scan mode. According to the characteristics of the ScanSAR of the HJ-1-C satellite, a geo-correction algorithm based on an equivalent RD model has been outlined in this paper on the basis of an ECS image processing algorithm and a traditional Range-Doppler location method. An azimuth mosaic was presented by a time series relationship, then the different burst was stitched by range, and the equivalent parameters were fitted to locations on the RD model. Finally, the ScanSAR image was geo-corrected. The HJ-1-C satellite data results showed that the location accuracy of ScanSAR for the HJ-1-C satellite was less than 100 m, and the geo-correction algorithm was realized in 10 s in fewer than 24 parMlel cores.