Title:
FIBRE OPTIC DISTRIBUTED SENSING
Document Type and Number:
WIPO Patent Application WO/2012/137022
Kind Code:
A3
Abstract:
The application describes methods and apparatus for distributed fibre sensing, especially distributed acoustic/strain sensing. The method involves launching at least first and second pulse pairs into an optical fibre, the first and second pulse pairs having the same frequency configuration as one another and being generated such that the phase relationship of the pulses of the first pulse pair has a predetermined relative phase difference to the phase relationship of the pulses of the second pulse pair. In one embodiment there is a frequency difference between the pulses in a pulse pair which is related to the launch rate of the pulse pairs. In another embodiment the phase difference between the pulses in a pair is varied between successive launches. In this way an analytic version of the backscatter interference signal can be generated within the baseband of the sensor.
Inventors:
LEWIS ANDREW (GB)
RUSSELL STUART (GB)
RUSSELL STUART (GB)
Application Number:
PCT/GB2012/050788
Publication Date:
June 27, 2013
Filing Date:
April 10, 2012
Export Citation:
Assignee:
QINETIQ LTD (GB)
LEWIS ANDREW (GB)
RUSSELL STUART (GB)
LEWIS ANDREW (GB)
RUSSELL STUART (GB)
International Classes:
G01D5/353
Domestic Patent References:
| WO2007049004A1 | 2007-05-03 |
Foreign References:
| US20050046860A1 | 2005-03-03 |
Attorney, Agent or Firm:
DAVIES, Philip (120 Redcliff Street, Bristol Bristol BS1 6HU, GB)
Download PDF: