Perpendicular distance prediction of vibrations by distributed fiber optic sensing

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.