Seismic optical acoustic recursive sensor system
US6522797B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 1, 1998 |
| Grant date | Feb 18, 2003 |
| Priority date | — |
| Expiry date | Sep 1, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01H9/004
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A marine seismic fiber optic acoustic sensor system having internal mirrors with a low reflectivity written into the fiber to form a series of continuous, linear sensors incorporated in a single fiber, each sensor bounded by a pair of internal mirrors. A pulsed laser provides optical signals to the fiber at a pulse width less than twice the travel time to assure that there will be no phase or frequency modulation of signals returned from the sensors and reflected optical energy is returned through the same fiber to an optical coupler where it is input to a compensating interferometer to produce interference signals which are then time division multiplexed to produce signals corresponding to acoustic signals received by each mirror bound sensor. Calibration to remove local temperature effects is provided by using a desensitized reference fiber with internal mirrors identical to the sensitized fiber, by a piezoelectric stretcher built into the fiber or any other conventional calibration technique.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.