A COMPARISON OF IP ELECTRODE ARRAYS

Abstract

The responses of dipole‐dipole, pole‐dipole, and gradient arrays to a set of ten structures have been computed using the finite element method. Comparison of the responses indicates that: (1) The dipole‐dipole array usually gives the largest anomalies, but the anomalies rarely give information on dip of a structure and are strongly influenced by overburden irregularities. This array gives best overall resolution. (2) Pole‐dipole anomalies are almost as large as dipole‐dipole ones and have the same general form but show less resolution. The lower resolution and the asymmetry of this array make results more difficult to interpret. (3) The gradient array provides dip information and good horizontal resolution. Responses to thin vertical structures are weak, anomalies are strongly affected by overburden irregularities, and there is no effective depth discrimination.