Abstract: 1. A system for simulating wave reflections from an irregular-shaped moving bject which has been illuminated with energy of frequency F, said system comprising;a receiver (10) for said frequency F;a generator (14) of white noise voltage;means (13) for amplitude modulating frequency F with said white noise voltage to generate random bursts of frequency F;a radiating transducer (11);a bandpass filter (18) having a passband including said frequency F, the output of said filter being coupled to the input of said transducer, and the input of said filter being coupled to the output of said modulator means (13) to radiate said random bursts of frequency F;a second signal path between said modulator and filter including a time delay network (30) for randomly distorting the radiated bursts.

Abstract: 1. In a submarine simulation sonar beacon adapted for predetermined maneuing under water, a hull having a forward and an aft transducer for receiving an acoustical signal within said water, means disposed in said hull connected to said forward and aft transducers for comparing the time relationship of arrival of said acoustical signal thereat, means coupled to said comparing means for generating an output signal having a characteristic which is a function of said time relationship, means coupled to said generating means for amplitude and highlight modulation of said output signal, and transmitting transducer means mounted on said hull and coupled to said last mentioned means for broadcasting said modulated signal through said water.

Abstract: 1.