Research and application of zoom-FFT algorithm on spectrum analysis of long period magnetotelluric

摘要

Spectral analysis on the electromagnetic field collected in the field can directly determine the quality of the data, through quantitative analysis of the data 's signal to noise ratio can determine the credibility of the data. The priority of magnetotelluric field data processing is to filter out good data segments which have high credibility and reliability, and it will make greatly reduce the error bars in the Robust analysis ,the calculated result of apparent resistivity and phase information will be more reliable and true. Applied Zoom-FFT algorithm into spectrum analysis of long period magnetotelluric, Zoom-FFT is a kind of computational efficiency, accuracy and flexibility are rather ideal method, this paper described the principle of Zoom-FFT algorithm and showed Zoom-FFT's results applied on spectrum analysis of long period magnetotelluric. Experiment showed that Zoom-FFT exhibited good flexibility, better effect and strong applicability. The comparison data processing results of one long period magnetotelluric sounding in Longmen mountain region showed that the results after filtering out more continuous smooth curve, closer to the physical underground electrical distribution.