A method and
system for measuring cable strain based on
optical fiber stretching relates to the field of on-line monitoring of cables with optical fibers, and the method comprises the following steps: modulating a correlation sequence to a detection
wavelength to form a detection optical
signal, and sending the detection optical
signal to an
optical fiber line of a cable to be measured; receiving a reflected
signal or a
loopback signal in the
optical fiber line, performing correlation operation on the reflected signal or the
loopback signal and the correlation sequence, and determining the time
delay of a correlation peak of the reflected signal or the
loopback signal; according to the time
delay of the reflection signal, determining the length of an optical
fiber through which the optical signal passes from the transmitting end to each reflection point; or determining the optical
fiber length of the optical
fiber line from one end to the other end according to the time
delay of the loopback signal; comparing the length of the optical fiber with a corresponding reference
record to obtain the strain of the optical fiber; and obtaining the strain of the cable according to the corresponding relation between the strain of the optical fiber and the strain of the cable. According to the invention, the interference on the measurement result under temperature and dynamic conditions can be avoided, and the technical problem that the cable strain cannot be accurately measured in the prior art is solved.