Sonar signal processing and display technique

Claim 1

A three color display system for sonar systems, comprising; a. a sonar signal projector and receiver system including first, second, and third guns in a three gun color tube; b. first, second, and third threshold circuits in said receiver individually controlling voltage applied to said first, second and third guns in said colored tube; c. an input circuit adapted to receive a sonar signal echo return; d. first, second, and third amplifier circuits coupled to receive a signal from said input circuit and to said first, second, and third threshold circuits respectively, to provide an amplified signal from said input to said threshold circuits; e. a clock circuit in said sonar signal projector; f. an automatic gain control circuit, and a time delay circuit coupled to receive a signal from said clock circuit and coupled to said first amplifier circuit for controlling the output of said first amplifier; g. a first time varying gain circuit coupled to said clock circuit and to said second amplifier, a second time varying gain circuit coupled to said clock circuit and to said third amplifier, said clock circuit generating signals to actuate said automatic gain control circuit and said first and second time variable gain circuits, said first amplifier circuit generating a signal thru said first threshold circuit to produce a display on the face of said tube from said first color gun including a target, a target shadow area and a background scatter signal, said second and third amplifiers generating signals to produce selected target signals and background scatter signals from said second and third guns.