Sonar detection system

Abstract

Abstract A SIGNAL-PROCESSING SYSTEM FOR ECHO-RANGING SONAR IS DESCRIBED WHEREIN A FIRST EMBODIMENT SHOWS THE PROCESSING SYSTEM WITH A PREFORMED BEAM PHASE COMPARISON TYPE OF SONAR, AND A SECOND EMBODIMENT SHOWS AN ESSENTIALLY SIMILAR SYSTEM IN CONJUNCTION WITH A SOAR OF THE PREFORMED BEAM AMPLITUDE TYPE. THE TRANSMITTER SECTIONS OF EACH INCLUDE AN OSCILLATOR FOR GENERATING A HIGH FREQUENCY SIGNAL, AND MEANS ARE SUPPLIED FOR CONTROLLING THE LENGTH OR DURATION OF TRANSMITTED PULSES. IN ADDITION, SWITCHING MEANS ARE PROVIDED FOR SEPARATING NORMAL TRANSMIT PULSE INTO A PULSE TRAIN WITH COMPARATIVELY BRIEF ON AND OFF TIMES, AND THIS SWITCHING IS COORDINATED WITH POST DETECTION PROCESSING MEANS IN THE RECEIVER SUCH THAT RETURN SIGNALS OF LENGTH COMPARABLE TO THE LENGTH OF THE INDIVIDUAL PULSES IN THE PULSE TRAIN ARE FILTERED OUT. LONGER PULSES WHICH ARE RECEIVED BECAUSE OF THE CHARACTERISTIC OF REFLECTIONS FROM LARGER OBJECTS TO BECOME ELONGATED, AND THUS "FILL IN" THE TRAIN, REPRESENT LARGER REFLECTING OBJECTS AND ARE NOT FILTERED BUT ARE SUPPLIED TO BRIGHTEN THE CATHODE RAY TUBE DISPLAY. THE SWITCHING MEANS IS VARIABLE TO ADJUST THE LENGTH OR DURATION OF THE "ON" AND "OFF" TIMES AND THE NUMBER OF SUCH CYCLES IN EACH TRAIN OF PULSES.

Inventors

• 👤 Ernest P Longerich
• 👤 Erland W Rudy

Bibliographic Details