说明：  雷达信号处理中相参积累，生成线性调频程序，加噪声，形成回波，进行数字下变频， 抽取，再通过匹配滤波器，进行相参积累，非常完整的程序
(In radar signal processing, coherent accumulation generates LFM program, adds noise, forms echo, performs digital down conversion, extraction, and then conducts coherent accumulation through matched filter, which is a very complete program.)