Distributed acoustic sensing system using different coherent interrogating light patterns and corresponding sensing method
US10935417B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 22, 2018 |
| Grant date | Mar 2, 2021 |
| Priority date | — |
| Expiry date | Apr 3, 2039 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/35361
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A distributed acoustic sensing (DAS) system has a coherent light source device that repeatedly sends a coherent interrogating light pattern (CILP) into an optical sensing fiber during a measurement duration that is equal to or greater than a down-up travel time of the optical sensing fiber. The CILP is one of a plurality of patterns composed of coherent carrier light. A detection device detects backscattered light in the optical sensing fiber in response to the CILP and generates a signal indicative of the detected backscattered light. An evaluation device analyses the signal. Each CILP has similar physical properties that render the light patterns indistinguishable by comparing physical properties of the backscattered light responsive to at least two successive interrogating light patterns as detected. The coherent light source device can change the time between successively sent interrogating light patterns after the passing of at least one measurement time duration.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.