Retracted: Induction-free acquisition range in spectral time- and frequency-domain induced polarization at field scale

Abstract

Spectral induced polarization imaging is a valuable method in near-surface hydrogeological and environmental investigations. Many field applications have been presented during the last 20 years, both in frequency and time domain. Despite the electromagnetic inductive effects always occurring in induced polarization measurements, they are usually disregarded in the spectral inversion of the data. Consequently, in order to invert only data with negligible inductive effects, the frequency and time ranges of both frequency-domain and time-domain data have often to be restricted, limiting the higher invertible frequency and the smaller invertible time. Consequently, this study investigates the induction-free acquisition range of both frequency-domain and time-domain acquisitions, computing the electromagnetic inductive effects of homogeneous media, with theoretical and field examples. It is found that it is much easier to get induction-free early times than induction-free high frequencies. For nested arrays it is difficult to measure a significant spectral range in the frequency domain, but also with the dipole-dipole array the inductive effects are not negligible with the typical settings used in field applications.