US 12,111,189 B2
Object localization and threat classification for optical cable protection
Ming-Fang Huang, Princeton, NJ (US); Ting Wang, West Windsor, NJ (US); and Shaobo Han, Princeton, NJ (US)
Assigned to NEC Corporation, Tokyo (JP)
Filed by NEC Laboratories America, Inc., Princeton, NJ (US)
Filed on Apr. 4, 2021, as Appl. No. 17/221,822.
Claims priority of provisional application 63/139,059, filed on Jan. 19, 2021.
Claims priority of provisional application 63/006,140, filed on Apr. 7, 2020.
Prior Publication US 2022/0316921 A1, Oct. 6, 2022
Int. Cl. G01D 5/353 (2006.01); G01H 9/00 (2006.01); G06V 20/58 (2022.01); G08B 21/18 (2006.01)
CPC G01D 5/353 (2013.01) [G01D 5/35361 (2013.01); G01D 5/35364 (2013.01); G01H 9/004 (2013.01); G06V 20/58 (2022.01); G08B 21/18 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A method of operating a distributed optical fiber sensing system for object localization and threat classification for optical cable protection and early warning, said system comprising:
a length of optical fiber; and
a distributed optical fiber sensing interrogator in optical communication with the length of optical fiber;
said method comprising:
operating the distributed optical fiber sensing interrogator and detecting, at a detection point along the length of the optical fiber, vibrations produced by a vibration source; and
determining, a directional movement of the vibration source relative to the detection point by comparing a cut-off vibrational frequency produced by the vibration source at a first time t1 and cut-off vibrational frequency produced by the vibration source at a second time t2;
wherein the cut-off vibrational frequency produced by the vibration source is greater when the vibration source is physically closer to the detection point and a higher vibrational frequency is observed as compared to when the vibration source physically further away from the detection point and a lower vibrational frequency is observed.