SONAR SYSTEM ILIZED THEREWITH (U)EREWITH (U)D THEREWITH (U)EREWITH (U)

Assignee

Filed

Nov 2, 1973

Granted

Dec 25, 1990

Location

PANAMA CITY FL US

Abstract

A doppler compensated sonar system is disclosed as including a transmitternd a receiver. The receiver of the disclosed preferred embodiment is a single channel receiver which incorporates a mixer and a narrow pass band filter connected in series therein. A phase lock loop of the negative feedback type is connected between the control input and the output of said mixer which effectively determines the occurrence of any doppler effects being processed in said receiver channel and compensates therefor by appropriate adjustment of the frequency of the signal supplied to the control input of said mixer, thereby causing the remainder of said receiver channel, including said narrow band pass filter, to process received target signals without any doppler effects being present therein. When mounted on a fast moving marine vehicle, this doppler compensated sonar system aids considerably in the avoidance of floating logs, submerged tree stumps, and other hazardous objects and debris thereby during the navigation thereof through uncharted waters.

Source: Google Patents