Bob Goddard         Senior Physicist         EIS Department         Applied Physics Laboratory         University of Washington	SST, or Sonar Simulation Toolset, is a computer program that produces simulated sonar signals, enabling users to build an artificial ocean that sounds like a real ocean. Such signals are useful for designing new sonars, testing existing sonars, predicting performance, developing tactics, training operators and officers, planning experiments, and interpreting measurements. SST's simulated signals include reverberation, target echoes, discrete sound sources, and background noise with specified spectra. Externally generated or measured signals can be added to the output signal or used as transmissions. Eigenrays from the Generic Sonar Model (GSM) or the Comprehensive Acoustic System Simulation (CASS) can be used, making all of GSM's propagation models and CASS's GRAB propagation model available to the SST user. A command language controls a large collection of component models describing the ocean, sonars, noise sources, targets, and signals. The software runs on Windows and several different Unix platforms.