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:
Oct. 07, 2025
Filed:
Apr. 25, 2022
Optasense Holdings Limited, Camberley, GB;
Richard Hooper, Farnborough, GB;
Roger Crickmore, Farnborough, GB;
Optasense Holdings Limited, Camberley, GB;
Abstract
This application relates to methods and apparatus for distributed fibre optic sensing. The apparatus includes an optical arrangement configured to generate a local oscillator signal (LO) and also to repeatedly interrogate a sensing optical fibre. Each interrogation comprises at least one pulse of coherent optical radiation at a launch frequency, which differs from that of the local oscillator signal by a carrier frequency. A mixer mixes backscatter signal from the sensing fibre with the local oscillator signal; and a detector arrangement provides at least one corresponding digital detector output signal (DX, DY). A processor processes each digital detector output signal to down-convert the digital detector output signal to a respective baseband signal based for each carrier frequency and convert each baseband signal to a phase signal. The processor is operable to apply time-domain low pass filtering to each baseband signal with a cut-off frequency, which is less than half the interrogation rate.