An improved Levenberg-Marquardt algorithm for extracting the features of Brillouin scattering spectrum

To extract the features of the Brillouin scattering spectrum in distributed sensing systems, an improved Levenberg-Marquardt (L-M) algorithm based on finite element analysis (FEA-LM algorithm) is proposed. The simulation data of different linewidth and signal-to-noise ratio (SNR) are analyzed by using the FEA-LM algorithm and the Brillouin center frequency shifts are extracted. The operational precision of the L-M and FEA-LM algorithms are compared in a certain range of initial value. The result shows that the FEA-LM algorithm can be appropriate for extracting the feature of the Brillouin scattering spectrum with different linewidth and SNR. Moreover, it has an advantage in precision by comparing with the L-M algorithm.