Pulled Array Continuous Vertical Electrical Sounding (Pa-Cites) With An Additional Inductive Source.

Abstract

Electrical and electromagnetic profiling methods are used extensively in environmental geophysical investigations for many different purposes. The PA-CVES method (Pulled-Array Continuous Vertical Electrical Sounding), where a tail of electrodes is towed behind a small vehicle while continuously measuring in many electrode configurations, has been used extensively for mapping the vulnerability of aquifers. Measurements are done for every 1 metre and 10- 15 km of profile can be made in one day. This paper presents a theoretical study of the resolution capabilities of PA-CVES measurements, as they are now performed, and an experimental design study for including an inductive source in the measuring equipment. The joint interpretation of the galvanic data set of ordinary PA-CVES measurements and a small number of inductive data from a horizontal magnetic dipole source will significantly enhance the resolution capabilities of the data set. The study is carried out by analyzing the uncertainty of the model parameters of a one-dimensional three layer model using the covariance matrix of the inversion problem.