OPGW optical cable sag monitoring method and system based on BOTDR strain measurement

The invention discloses an OPGW (Optical Fiber Composite Overhead Ground Wire) optical cable sag monitoring method and system based on BOTDR (Brillouin Optical Time Domain Reflectometry) strain measurement, relates to the technical field of optical cable sag monitoring, and is used for solving the problems of high cost, need of power supply and the like in the existing sag monitoring scheme. The method is characterized by comprising the following steps: acquiring a Brillouin spectrum of an OPGW optical cable at a fixed time interval based on a BOTDR (Brillouin Optical Time Domain Reflectometer), wherein the OPGW optical cable is erected on an equal-height tower and the shape of the OPGW optical Processing the Brillouin spectrum at the fixed time interval to obtain a Brillouin frequency shift variation and a Brillouin frequency shift variation caused by temperature at a downlead, and further demodulating the strain of the OPGW; according to the OPGW optical cable strain, calculating to obtain the optical cable