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A. Flores-Orozco, J. Gallistl, M. Bücker, K. Williams:
"Decay curve analysis for data error quantification in time-domain induced polarization imaging";
Geophysics, Volume 83 (2018), 2; 75 - 86.

In recent years, the time-domain induced polarization (TDIP)
imaging technique has emerged as a suitable method for the
characterization and the monitoring of hydrogeologic and biogeochemical
processes. However, one of the major challenges
refers to the resolution of the electrical images. Hence, various
studies have stressed the importance of data processing, error
characterization, and the deployment of adequate inversion
schemes. Awidely accepted method to assess data error in electrical
imaging relies on the analysis of the discrepancy between
normal and reciprocal measurements. Nevertheless, the collection
of reciprocals doubles the acquisition time and is only
viable for a limited subset of commonly used electrode configurations
(e.g., dipole-dipole [DD]). To overcome these limitations,
we have developed a new methodology to quantify the
data error in TDIP imaging, which is entirely based on the
analysis of the recorded IP decay curve and does not require
recollection of data (e.g., reciprocals). The first two steps of
the methodology assess the general characteristics of the decay
curves and the spatial consistency of the measurements for the
detection and removal of outliers. In the third and fourth steps,
we quantify the deviation of the measured decay curves from
a smooth model for the estimation of random error of the
total chargeability and transfer resistance measurement. The error
models and imaging results obtained from this methodology
- in the following referred to as "decay curve analysis" - are
compared with those obtained following a conventional normalreciprocal
analysis revealing consistent results. We determine
the applicability of our methodology with real field data collected
at the floodplain scale (approximately 12 ha) using multiple
gradient and DD configurations.

In recent years, the time-domain induced polarization (TDIP)
imaging technique has emerged as a suitable method for the
characterization and the monitoring of hydrogeologic and biogeochemical
processes. However, one of the major challenges
refers to the resolution of the electrical images. Hence, various
studies have stressed the importance of data processing, error
characterization, and the deployment of adequate inversion
schemes. Awidely accepted method to assess data error in electrical
imaging relies on the analysis of the discrepancy between
normal and reciprocal measurements. Nevertheless, the collection
of reciprocals doubles the acquisition time and is only
viable for a limited subset of commonly used electrode configurations
(e.g., dipole-dipole [DD]). To overcome these limitations,
we have developed a new methodology to quantify the
data error in TDIP imaging, which is entirely based on the
analysis of the recorded IP decay curve and does not require
recollection of data (e.g., reciprocals). The first two steps of
the methodology assess the general characteristics of the decay
curves and the spatial consistency of the measurements for the
detection and removal of outliers. In the third and fourth steps,
we quantify the deviation of the measured decay curves from
a smooth model for the estimation of random error of the
total chargeability and transfer resistance measurement. The error
models and imaging results obtained from this methodology
- in the following referred to as "decay curve analysis" - are
compared with those obtained following a conventional normalreciprocal
analysis revealing consistent results. We determine
the applicability of our methodology with real field data collected
at the floodplain scale (approximately 12 ha) using multiple
gradient and DD configurations.

geophysics

https://doi.org/10.1190/geo2016-0714.1