The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 11, 2018
Filed:
Jun. 27, 2014
Optasense Holdings Limited, Farnborough, Hampshire, GB;
Alastair Godfrey, Farnborough, GB;
Roger Ian Crickmore, Farnborough, GB;
Optasense Holdings Limited, , GB;
Abstract
This application describes method and apparatus for fiber optic distributed acoustic sensing (DAS) that allow for quantitative estimation of relatively large and continuous stimuli acting on the sensing fiber. An optical fiber () is interrogated with optical pulse and the Rayleigh backscatter detected to provide a DAS sensor. The method involves identifying a first stimulus acting on at least one sensing portion of the optical fiber, which results in an effective optical path length change within said sensing portion of at least the wavelength of the optical radiation. Such a path length change will result in signal wrapping leading to an observed variation () in backscatter intensity. The frequency of variation is detected and can be used to estimate the rate of change of path length. The method can be used to estimate strain rate and/or rate of change of temperature.