Abstract:

In the low frequency electromagnetic signal,in order to get the fine structure of a certain spectrum within the narrowband,improve the frequency resolution of spectrum,and meet the requirement of good real-timeness,this paper puts forward the frequency refining technology based on the fast Fourier transform algorithm.Through polyphonic system frequency refinement,we amplify a local spectrum to facilitate fast and accurate analysis for the low frequency electromagnetic signal spectrum.Matlab is used for simulation of the low frequency electromagnetic signal by the method of polyphonic system frequency refinement.The simulation results show that this method is more effective and feasible than the Chirp Z transformation algorithm.

Key words: low frequency electromagnetic signal;frequency refinement;spectrum;polyphonic system refinement