The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 12, 1980
Filed:
Jun. 19, 1978
Joseph D Richard, Miami, FL (US);
Other;
Abstract
A seabed referenced fish detection system for detecting aquatic animals within a predetermined zone relative to the bottom of a body of water. Preferably, fish are detected within a predetermined zone contiguous with the bottom without the need for range switching to accommodate changes in depth. A pair of ultrasonic pulses are transmitted, preferably of different frequencies, and separated by a predetermined time delay. The bottom echo from the first ultrasonic pulse initiates a gate interval during which echoes from the second ultrasonic pulse are detectable. When the time delay and the gate interval are equal, the gate interval terminates immediately before the reception of the second bottom echo, so that only echoes from above the bottom, e.g., fish echoes, can trigger an audible output signal. Since fish detection events are un-ambiguously indicated by an audible signal, the need for a graphic recorder or C.R.T. to distinguish and interpret fish and bottom echoes is eliminated.