TRACE: A mechanism for acoustic simulation

Several years ago Honeywell´s Marine Systems Center in Seattle started work on aprogram to develop an acoustic signal processor for an underwater vehicle. We were aware that refraction and reflection of the direct signal from the surface and the bottom would yield multiple signals and that refraction, although ever-present, cannot be accurately predicted. It became apparent that on certain days processors operating in thew ater seemed to behave abnormally. Attempting to correlate this abnormal behavior with known conditions, we found indications that a combination of reflection and refraction, producing multiple signal paths, might cause the noted abnormalities. A search of existing literature shed little light upon the effects of multiple signal paths on the performance of an acoustic signal processor. As a result the authors developed TRACE, a fast and economical means for evaluating the effectiveness of underwater vehicles in a realistically simulated undersea environment. The Honeywell TRACE facility has proved its effectiveness in analyzing design parameters and verifying actual performance of sonar-guided underwater vehicles. A unique feature of the TRACE facility is that it subjects acoustic signal processors to a multiplicity of signals occurring in the acoustic environment as a result of refraction and reflection. This paper describes TRACE, including some of the models used and the hardware designed to implement those models.