A General Treatment of Source Motion on Total Acoustic Field with Application to an Isospeed Channel.

摘要

A treatment of the effects of aribitrary motion of a cw source and depth-dependent sound speed on the total acoustic field at a fixed receiving point is considered for an ocean with horizontal boundaries. Application of our general method is made to a constant sound speed channel in which the range-to-depth ratio is large, when the source follows a short straight-line path with constant velocity. Total field phase is investigated as a function of receiver time for various source trajectories and phase rate is examined in terms of an arbitrary, but fixed, acoustic frequency. It is shown that source motion may be accounted for by assuming the sound source to be stationary, and by replacing its frequency by approximate Doppler frequency. For long source trajectories, cumulative phase can be approximated as a hyperbolic function of time. The outputs of two uniform colinear arryas, together with power spectra there, are employed to illustrate one method for determining source speed, location, bearing, and frequency. (Author)