Fish detector capable of detecting species of fish
US4290125A · kind A · utility
Inventor
Key dates
| Filing date | Jul 23, 1980 |
| Grant date | Sep 15, 1981 |
| Priority date | — |
| Expiry date | Jul 23, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S15/96
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A fish detector capable of detecting species of fish. Two ultrasonic sounds at different frequencies and echoes are detected by receivers tuned to said different frequencies, respectively. The output signals from the receivers are converted into binary-coded signals and one of the binary-coded signal is divided by the other binary-coded signal. The ratio or quotient thus obtained is compared with a plurality of reference signals at different levels or strengths so as to detect whether or not the ratio or quotient is higher than the highest level or strength reference signal, lower than the lowest level or strength reference signal or between two reference signals at adjacent levels or strengths and subsequently to display in color depending upon a level of the ratio or quotient thus detected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.