The continuous gradient ray tracing system (CONGRATS)
CONGRATS, an acronym for the Continuous Gradient Ray Tracing System, is an integrated collection of ray tracing programs designed to model acoustic propagation and reverberation. The fundamental programs of the series, CONGRATS I, construct ray diagrams and generate eigenrays, that is, rays that join a given source to a given target [Ref. lJ. The most distinguishing feature of CONGRATS I is that the velocity of sound in the ocean is represented by a function of depth whose first derivative is continuous, and still permits one to integrate the resulting ray tracing equations in closed form.
SourceIn: SACLANTCEN Conference Proceedings No. 5 part 1, pp. 77-93.
Cohen, J. S.