Patent ID: 6388948
Filing Date: 2002-05-14
Classification: G01H,G01S

Abstract:
A method for determining the effective sound velocity between underwater points, the method comprising the steps of:providing a device for determining the effective sound velocity between the underwater points; feeding into the device the sound velocity profile from a source of sound energy located at an initial depth to a predetermined final target depth; feeding into the device a predetermined set of grazing angles; feeding into the device a predetermined number of target depths between the initial depth and the final target depth; calculating for each grazing angle and target depth a corresponding elevation angle and an effective sound velocity; feeding into the device a predetermined uniform set of elevation angles; determining for each elevation angle of the uniform set a pair of calculated elevation angles that correspond to a pair of successive grazing angles and a particular target depth wherein the particular elevation angle of the uniform set is between the pair of calculated elevation angles; interpolating the calculated effective sound velocity values associated with each elevation angle of the pair of calculated elevation angles to produce an interpolated effective sound velocity; repeating for each target depth used between the initial depth and the final depth the above-mentioned steps of determining for each elevation angle of the uniform set of pair of calculated elevation angles and interpolating the calculated effective sound velocity values; feeding parameters associated with an actual target, the parameters comprising an actual target depth and an actual target elevation angle; and selecting as the effective sound velocity between the source of sound energy and the actual target the interpolated effective sound velocity that corresponds to an elevation angle of the uniform set and a target depth that matches the actual target elevation angle and actual target depth, respectively.