Correction of CSAMT static shift using transformed phase
Shi Xian-xin1,2, Yan Shu3, Chen Ming-sheng1, Fu Jun-mei2
1. Xi'an Research Institute of China Coal Technology & Engineering Group, Xi'an, Shaanxi 710077, China;
2. School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China;
3. School of Computer Science and Telecommunication Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China
Abstract：The static shift makes measured apparent resistivity curves up and down parallel shifts in double logarithmic coordinate system.This badly impacts the accuracy of interpretation.Phase data have no relation with parallel shifting of apparent resistivity curves.They only have relation with their slope and the information contained in phase curves are as same as in the electric field or the magnetic field.However,high quality phase data are difficultly measured in practice.In this paper,transformed phase curves from single electric field component in measuring data are used to remove static shifts.The results show that the approach is effective.There are no under-corrected or over-corrected problems and no limitations of the observation point spread.The litter difference between the results of quantitative inversion with transformed phase and the results of inversion with amplitude of the electric field can be ignored.Just as EMP method in CSAMT data processing and interpretation,phase curves can be used not only for static shift correction but also in data interpretation with apparent resistivity.
