Abstract: This paper mainly discusses how to design the optimal mode for arranging the electrodes in multi-spacing system for apparent response observation. The basic foundation in designing the optimal mode for arranging the electrodes is the theory of horizontal layered earth media and related sensitivity coefficients. The accuracy of inversion calculation associated with the choice of different separations should also be considered. Then, taking Baodi station as an example, this paper discussed how to decide the size of each separation in multi-spacing observation for a given station with known electric structure. At last, using the multi-spacing system for apparent resistivity observation decided by the newly designed optimal model for arranging the electrodes, we processed the simulation observation data of the multi-spacing system. From the results it can be seen that variation of the true resistivity of each layer of the underground media can be seen that variation of the true resistivity of each layer of the underground media can be accurately calculated using the multi-spacing system decided by the method put forward in this paper.

Key words: Apparent resistivity, Multi-spacing system for apparent resistivity observation, Response coefficients, Optimal mode for arranging the electrodes