M. Israil

A simple method of interpreting dipole resistivity soundings

A computational method has been developed based on a linear relationship between apparent resistivity and the kernel function through a matrix operator. Forward modeling of dipole apparent resistivity values over a one-dimensional layered earth model as well as the inversion of electrical sounding data can be easily accomplished using this matrix operator. For a few two-layer, three-layer, and four-layer earth models, the apparent resistivity values can be calculated quickly and accurately. It is shown that the technique is adaptable to automatic interpretation in both the resistivity and the kernel domains.

Reply by the authors to E. Szaraniec

We thank Dr. Szaraniec for taking a keen interest in our paper, but we are aware of the work of Santini and Zambrano (1981), Kumar and Chowdary (1982), and subsequent comments (Santini and Zambrano, 1982; Straub, 1984; Szaraniec, 1982, 1984.) The papers by Santini and Zambrano (1981) and Kumar and Chowdary (1982) are in fact referenced in our earlier paper (Niwas and Israil, 1987) dealing with resistivity‐data interpretation in the kernel domain.

On: “A simple method of interpreting dipole resistivity soundings; discussion and reply

The subject paper consists in approximating the apparent resistivity data by using a linear combination of suitable functions chosen in such a way that (1) they give a good approximation up to the desired precision and (2) they allow the kernel function to be determined analytically. Surprisingly enough, no mention is made that such an approach, especially directed toward interpretation of resistivity soundings, was first proposed by Santini and Zambrano (1981). The subject was subsequently continued by Kumar and Chowdary (1982) and commented by Santini and Zambrano (1982), Straub (1984), and Szaraniec (1982, 1984).