• 责任者：Liang Huaqing (College of Geophysics and Information Engineering ; China University of Petroleum ; Beijing 102249 ; China) ; Geng Min
• 刊名：Journal of China University of Petroleum
• 出版年：2013
• 卷期：37(4)
• 关键词：随钻测量 ; measurement while drilling ; 磁法勘探 ; magnetic prospecting
• 页码：p.83-87,99
• 图表：illus., 2 tables, 15 refs.
• 分类号：1600
• issnNo：ISSN1673-5005
• isbnNo：CN37-1441/TE

     According to the weak and frequency-varying characteristics of rotating magnetic signal, a filtering method was developed based on discrete Fourier transform （DFT） double-peak spectrum value. Firstly, the frequencies of two peaks in the main-lobe of sig-nal amplitude spectrum were searched. Secondly, the initial frequency value was reconstructed based on the two frequencies and the true frequency value was solved by Newton＇s method. Finally, the signal amplitude was recovered. The proposed method was tested by computer simulation and outdoor experiments. The simulation results show that the double-peak method is much better than the single-peak method based on DFT. The experimental results agree well with the variation law of magnetic field strength with distance. The proposed method is proved to be effective and accurate. The method can track the varing frequency aeeuratly and extract the weak am-plitude precisely.