中文说明：
提供了关于SAR(合成孔径雷达)中常用的BackProjection算法的Matalb实现(bpbasic.m). 同时提供了生成回波历史相位并应用BP成像的实例(dianmubiaobp.m). 对BP算法加入了注解和一些方便理解生成的中间图像。
English Description：
The MATALB implementation (bpbasic. M) of backprojection algorithm commonly used in SAR (synthetic aperture radar) is provided. At the same time, an example of generating echo historical phase and applying BP imaging (dianmubiaobp. M) is provided. Notes and some intermediate images for easy understanding of BP algorithm are added.