フーリエ変換を使用する地磁気異常解析法の誤差について

概要

論文の詳細を見る
Reduction to the pole and upward continuation methods are used to know the features of magnetic bodies causing magnetic anomalies. These methods are accomplished by wave-number domain using the Fourier transform. In general, transformation to wave-number domain is done by the method of the Fast Fourier Transform(FFT). The number of data must be powers of two to apply the FFT. We used to add the data to the observed magnetic anomalies either by interpolation or extrapolation to fixed in number of data, because it was hard to get the number of data powers of two for field observation. It is said that transformation errors using finite length data inevitably occur in the boundary of the data. In this paper, the author evaluated errors of reduction to the pole (RTP) calculated from the anomalies added extrapolation values in the outer area of original theoretical anomalies caused by a rectangular magnetic model. This handling of the data number by the extrapolation corresponds to extend the data range or the data length. Errors of RTP calculated from the anomalies added extrapolation values were smaller than those of original theoretical anomalies. The result means that handling of the data number by extrapolation is possible to reduce calculation errors in the geomagnetic analysis method such as the RTP.
東海大学の論文
2002-03-30