Rectangular-window band-pass amplitude-preserved filtering data processing method used in geophysical exploration

Abstract

The invention discloses a rectangular-window band-pass amplitude-preserved filtering data processing method in a geophysical exploration technology. An interpolation method is used to perform grid to gravity and magnetic data. The gravity and magnetic data with a low accuracy is used to perform supplement and fringing. Rapid Fourier forward transformation is performed. Two initial band-pass filtering frequency response functions are calculated in a wave number domain. Two initial filters are compensated and are multiplied so as to obtain a rectangular window band-pass filter. Through rapid Fourier inverse transformation, the gravity and magnetic data after the band-pass filtering can be obtained. Inverse fringing processing is to extract the gravity and magnetic data which is in a size oforiginal data and is processed after the band-pass filtering. The filter of the invention can achieve the amplitude-preserved signal in the passband and can achieve that the signal is completely inhibited in stop band. Gravity and magnetic abnormal low frequency background and high frequency noise can be suppressed. The intermediate-frequency useful signal in the wave number domain which is the rectangular window can be protruded.

Description

technical field [0001] The invention relates to the technical field of geophysical prospecting, in particular to a method for processing rectangular window bandpass amplitude-preserving filtering data in geophysical prospecting. Background technique [0002] Geophysical prospecting includes gravity, magnetic force, electrical method, seismic prospecting, etc. Gravity and magnetic force are two geophysical methods with the earliest development, mature theory and wide application. Gravity and magnetic methods cover a wide area and are economical and fast, and are widely used in various fields such as oil and gas, solid mineral resource exploration, regional and deep structure research, environmental and engineering surveys, etc. Gravity and magnetic prospecting include three parts: data acquisition, processing and interpretation. [0003] Digital filtering is to filter signals in the case of digital signals. In signal digital processing, low-pass, high-pass, and band-pass fil...

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Problems solved by technology

There are three main problems with other filters other than compensating smooth filtering. One is that the filter is not a continuous function, that is, there is a sudden break between the passband and the stopband, which causes the Gibbs phenomenon; the other is that it is not suitable for highlighting in The wavenumber domain is an intermediate frequency useful signal with a rectangular window; the third is that the attenuation area between the passband and stopband of the filter is relatively large, and the passband and stopband are not completely separated. The in-band signal is not completely suppressed, which not only affects the subsequent qualitative analysis, but more seriously affects the quantitative analysis

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