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:
Aug. 27, 1985
Filed:
Sep. 29, 1982
Joseph D Richard, Pensacola, FL (US);
Other;
Abstract
A directional Doppler fish movement detector uses a relatively low ultrasonic frequency to minimize particulate scattering and absorption losses in turbid lakes and streams. The low ultrasonic frequency also minimizes Doppler noise caused by boat drift and wave action. To compensate for the relatively low frequency Doppler signals which result, including sub-sonic Doppler signals from slow moving fish, means are provided for doubling, or otherwise multiplying, the frequency of the Doppler signal to improve audibility. Means are also included which allow the relatively wide beam of the Doppler fish movement detector to be directed over a wide horizontal angle, and in one of the preferred configurations, the transducer assembly is attachable to the underwater portion of an electric propulsion motor so that the ultrasonic beam is directed along the line of thrust. Although useful for the detection of normally swimming fish, a preferred use is in cooperation with a fishing effort in which otherwise inactive fish are provoked into impulsive and detectable movements by bait casting into the area covered by the relatively wide ultrasonic beam.