A Direct Induced-Polarization Decoupling Scheme by Chop-Wave

It is known that the electromagnetic coupling effect is a disturbance factor in induced‐polarization measurements. Based on the different appearances of EM coupling effect and IP effect in measured dual‐frequency waveform, a direct decoupling scheme by chop‐wave is presented in this paper. The method is able to eliminate EM coupling effect directly during the field data acquisition, and it does not suffer loss of IP information by and large. This paper has mainly discussed several aspects, which include the fundamentals of chop‐wave, the distortion of normal dual‐frequency wave resulting from chopping wave, chopper of existing pure EM coupling effect and IP effect's loss due to chop‐wave. The numerical results show that the scheme reduces and eliminates EM coupling effect markedly and can provide some parameter bases for the development and design on the correlative instrument. Thereby, it is worth generalizing the chop‐wave for decoupling scheme in the induced polarization method.