Circuit for automatic seabed discrimination
US4648081A · kind A · utility
4Cited by
5References
13Claims
0Family size
Inventor
Key dates
| Filing date | Jan 19, 1984 |
| Grant date | Mar 3, 1987 |
| Priority date | — |
| Expiry date | Jan 19, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S15/96
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A circuit automatically determines the nature of the seabed over which a vessel is passing, indicating via an audible or other warning signal when a fishing vessel is above a type of seabed which might damage the fishing net. The circuit is responsive to an echosounder signal and raises an alarm when a amplitude of the second bottom echo component in the echosounder signal exceeds a selected threshold level. Preferably the analog echosounder signal is subject to threshold discrimination to provide a pulse-form signal which is then processed by a digital logic circuit to isolate the second bottom echo component.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.