Sonar equipment for vessel measuring velocity distribution - sounds depth vertically and at angle and computes effective geometric angle

摘要

A sonar device continuously measures the bending of a sound wave. The process is based on the principle that the speed of sound propagated through water is a function of temp. and of the salt content. The measuring process enables the velocity distribution between the surface of the water and the bottom of the sea and hence the reflection of the sound wave to be determined. This is achieved without submerging a probe or reducing the speed of the vessel. The depth of the water is first sounded vertically and the results stored. This process is repeated in one or more directions at an angle to the vertical. Depending on the movement of the vessel, the result of the vertical sounding is compared with the sounding of a given angle instantaneously. The effective geometrical angle is first established for the angular sounding.