Estimation of the Mean Velocity of Acoustic Signal Propagation for Sea Operations

A representative velocity profile and a priori bathymetric information about possible undersea device depths are the only data required to generate coefficients for a three-dimensional quadric polynomial surface which then expresses an accurate estimate of the mean velocity of acoustic signal propagation as a function of measured travel time and receiver depth. The resultant polynomial estimator is easily implemented in real-time navigating, station keeping, and undersea device tracking software to account for the variable refraction effects on mean velocities encountered in raypath trajectories that extend from the vertical out to and including the limiting direct raypaths.