Patent ID: 6819629
Filing Date: 2004-11-16
Classification: G01S

Abstract:
A method for locating the position of objects in a body of water comprising:a. selecting a fixed rate at which ultrasonic pulses are to be generated that is different from the rate of other units within range; b. generating a plurality of ultrasonic pulses at said fixed rate, sensing any signals received after generating a first of said ultrasonic pulse and measuring the time interval between said first of said ultrasonic pulses and the sensing of said signals received after said first of said ultrasonic pulse; c. sensing any signals received after generating a second of said ultrasonic pulses, and measuring the time interval between said second of said ultrasonic pulses and the sensing of said signals received after said second of said ultrasonic pulses; d. comparing the time intervals between said first of said ultrasonic pulse and the sensing of the signals received after said first of said ultrasonic pulses with the time intervals between said second of said ultrasonic pulse and the sensing of signals received after said second of said ultrasonic pulse, to see which of said time intervals match; and e. rejecting any signals that do not have time intervals that match as interfering ultrasonic signals.