Dual beam doppler shift hydrophone
US4998225A · kind A · utility
11Cited by
3References
5Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Dec 10, 1979 |
| Grant date | Mar 5, 1991 |
| Priority date | — |
| Expiry date | Dec 10, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01H9/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A dual beam hydrophone wherein a reference laser beam and a signal laser m are both modulated simultaneosuly by the movement of reflecting surfaces responding to pressure variatrions due to an impinging acoustic wave. Each beam, travels the same path length within the hydrophone before being detected, thus eliminating any otherwise needed signal compensation. The reference beam and signal beam are acoustically modulated 180 degrees out of phase which reduces by one half the number of reflections normally required to produce the same sensitivity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.