Echo simulator for active sonar

摘要

A target echo simulator with reverberation and ambient noise for testing an active sonar system. A transmit enable pulse from a sonar transmitter establishes a sequence of operations in which a target echo generator, reverberation generator and ambient noise generator produce a composite signal. The target echo generator produces a pulse modulated output pulse of a characteristic sonar frequency. The reverberation generator produces an amplitude modulating or envelope controlled output at a frequency of a carrier that is offset from the target echo carrier frequency. An ambient noise generator constantly produces ambient noise. A summing amplifier combines the generated signals to produce a composite signal for transfer to a receive connection on the active sonar system.