US 11,914,040 B2
Spatially resolved perturbation detection using line monitoring system
Maxim A. Bolshtyansky, Millstone, NJ (US); and Alexei N. Pilipetskii, Colts Neck, NJ (US)
Assigned to SubCom, LLC, Eatontown, NJ (US)
Filed by SUBCOM, LLC, Eatontown, NJ (US)
Filed on May 10, 2021, as Appl. No. 17/316,454.
Prior Publication US 2022/0357448 A1, Nov. 10, 2022
Int. Cl. G01C 3/08 (2006.01); G01S 17/26 (2020.01); G01S 17/34 (2020.01); G01S 17/36 (2006.01)
CPC G01S 17/34 (2020.01) [G01S 17/26 (2020.01); G01S 17/36 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A line monitoring system, comprising:
a laser source to launch a plurality of pulsed probe signals;
an optical transmission system, comprising a plurality of loopbacks, disposed to receive the plurality of pulsed probe signals, and direct the plurality of pulsed probe signals through the plurality of loopbacks;
a polarization rotator, disposed between the laser source and the optical transmission system, to rotate a polarization of the plurality of pulsed probe signals,
a receiver to receive a plurality of return signals, derived from the plurality of pulsed probe signals from the optical transmission system; and
a perturbance detection system, coupled to the receiver, and arranged to:
measure a phase difference between a polarization of a pair of return signals of the plurality of return signals, the pair of return signals being received from a pair of loopbacks of the plurality of loopbacks; and
determine a location of a perturbance, based upon the phase difference,
wherein the plurality of return signals are each characterized by a phase of a polarization rotation returned by a given loopback, and
wherein the perturbance location system is arranged to determine the location by:
measuring a change in a value of the phase difference, wherein the phase difference is associated with a polarization returned by adjacent loopbacks of the pair of loopbacks.