US 12,000,729 B2
Perpendicular distance prediction of vibrations by distributed fiber optic sensing
Shaobo Han, Princeton, NJ (US); Ming-Fang Huang, Princeton, NJ (US); Yuheng Chen, South Brunswick, NJ (US); and Milad Salemi, Somerset, NJ (US)
Assigned to NEC Corporation, Tokyo (JP)
Filed by NEC Laboratories America, Inc., Princeton, NJ (US)
Filed on Dec. 20, 2021, as Appl. No. 17/555,990.
Claims priority of provisional application 63/192,183, filed on May 24, 2021.
Claims priority of provisional application 63/128,970, filed on Dec. 22, 2020.
Prior Publication US 2022/0196462 A1, Jun. 23, 2022
Int. Cl. G01H 9/00 (2006.01); G06N 7/01 (2023.01); G06V 10/28 (2022.01); G06V 10/44 (2022.01)
CPC G01H 9/004 (2013.01) [G06N 7/01 (2023.01); G06V 10/28 (2022.01); G06V 10/449 (2022.01); G06T 2207/30181 (2013.01)] 2 Claims
OG exemplary drawing
 
1. A method of operating a distributed fiber optic sensing (DFOS)/distributed acoustic sensing (DAS) system to determine perpendicular distance(s) from a DAS sensing fiber to vibration sources said method comprising:
operating the DAS system to measure baseline vibration levels and event characteristics at different perpendicular distances from locations along a length of sensing optical fiber that is part of the DAS system and collect a training dataset to establish canonical joint probability distribution of perpendicular distances from the sensing optical fiber and observed intensity;
integrating the measured baseline vibration levels and respective perpendicular distances from locations along the length of the sensing optical fiber to a geographic map;
generating a database of vibration intensity profiles for each perpendicular distance and location along the length of the sensing optical fiber;
determining background traffic vibrations in the database of vibration intensity profiles and removing same according to a median filtering methodology;
detecting a vibration through the effect of the DAS and determining a perpendicular distance from the sensing optical fiber of a source of the detected vibration; and
wherein the perpendicular distance determination is made from a DFOS stream of waterfall plots resulting from operation of the DAS system;
wherein the perpendicular distance determination includes an image binarization of the stream of waterfall plots; and
wherein the perpendicular distance determination includes generating an intensity profile at each perpendicular location using a join probability map by a Kernel Density or Gaussian Process Regression (GPR) process.