一、引言我们讨论一种处理单频脉冲回波测距系统的多普勒输出信号的方法(图1)。这一方法的目的是:在把信号送至报警信号提取设备的门限装置之前,消除混响的强烈的时变特征。这种声纳接收机主要包括波束形成、窄带滤波和包络检波等三部分。每个波束被分到若干个邻近的多普勒 I. INTRODUCTION We discuss a method of processing the Doppler output signal of a single-frequency pulse echo ranging system (Figure 1). The purpose of this method is to eliminate the strong time-varying signature of the reverberation before sending the signal to the threshold device of the alarm signal extraction device. This sonar receiver includes beam forming, narrowband filtering and envelope detection three parts. Each beam is divided into several adjacent Doppler