Submarine cable burial depth analysis and calculation method based on distributed optical fiber temperature measurement

The invention belongs to the field of submarine cable operation and maintenance, and particularly relates to a submarine cable burial depth analysis and calculation method based on distributed optical fiber temperature measurement. According to the method, finite element simulation software is used for establishing a three-dimensional electrothermal coupling finite element model of the submarine cable under different burial depths, load currents and environment temperatures, the model is used for solving temperature field distribution and change of the submarine cable, and optical fiber temperature data are extracted from the model; processing simulation data by using a multivariate nonlinear fitting method to obtain a submarine cable burial depth calculation formula taking the optical fiber temperature, the load current and the environment temperature as independent variables; the submarine cable burial depth can be directly calculated according to the temperature of the composite optical fiber in the submar