DescriptionThe frequency dependence of the induced polarization effect (IP), the socalled
spectral IP (SIP), has been demonstrated to be strongly correlated to important parameters in hydrogeological and environmental investigations. This has prompted the development of measuring and modelling techniques for an
enhancement in data quality for laboratory and field investigations at a broader frequency bandwidth.
Although SIP datasets have been traditionally collected in the frequencydomain
(FDIP), recent developments have demonstrated the capabilities to solve for the frequencydependence of the complex conductivity through the inversion of measurements collected in the timedomain (TDIP). In recent years, a few studies have addressed the comparison of both TDIP and FDIP methods; however,
mostly related to the imaging results and not the actual signalstrength.
Moreover, previous investigations have not addressed sources of error associated to TDIP and FDIP instruments. For FDIP we deployed measurements with the Radic Research SIP 256C and MPT DAS1; whereas ABEM Terrameter LS 2 and IRIS Syscal Switch Pro were used for TDIP. Hence, our investigation aims at comparing the IP response at a broad frequency bandwidth resolved through FDIP and TDIP measurements. Furthermore, a detailed discussion on the different sources of uncertainties effecting the IP data readings collected with different instruments. To provide a fair comparison, all measurements were performed using the same settings.
We present our results regarding the analysis of data errors. The analyses of signal strength are evaluated through comparison of data collected at different electrode separation. We observed that data collected through different instruments provide similar information, with comparable readings. Furthermore, resistivity revealed the same response and are comparable for different depth of investigations. The IP signals are also comparable but differs in data quality for higher frequencies/early times due to field setup and instrument techniques. Yet, each instrument revealed advantages and
disadvantages regarding the field robustness, easiness for deployment and frequency content.
|Period||2019 Mar 6|
|Event title||79th annual conference of the German Geophysical Society (DGG),|
Research output: Contribution to journal › Article › peer-review