Acoustic transfer function of the ocean for a motional source

The motional-source transfer characteristics of long-range acoustic propagations are derived based on the discrete multipath propagation model predicted by geometrical acoustics. Parameters are those associated with the characteristic solutions of the eikonal equation. A modified transfer function is formulated which relates the received signal to a particularly useful transformation of the source signal. The modified transfer function shows that a remotely received signal consists of the weighted superposition of a number of modified source signals both slightly compressed (or expanded) and translated in time. Both the compression and translation factors are random processes with deterministic means. Application of the model transfer function to a specific ocean profile exemplifies the ocean filter characteristics and the complex nature of the received signal from a cw source in motion.