中文说明：
多个脉冲积累后可以有效地提高信噪比，中频积累时要求信号间有严格的相位关系，即信号时相参的，所以称为相参积累。
English Description：
The signal-to-noise ratio (SNR) can be effectively improved after multiple pulses are accumulated. If the signal is accumulated, there must be a strict phase relationship between the signals, that is, the signals are time coherent, so it is called coherent accumulation.