This paper deals with feature of extraction target signal with ISAR radar.Since the size of the rarget is larger than range resolution of ISAR radar
the back-scattered power of the target is represented as a function of time.The method of improved detection performance with ISAR are FFT and signal amplitude integration of each range cell
which presents the signal of the target.But in LRR the signal integration is vectoried integration
the output forms of the methods are given by this paper and theoretical calculation agrees with experimental measurement satisfactorily.