Overview

The ERT & IP modules are designed for processing and inversion of ERT and induced polarization data. A unique feature is the ability to invert the full decays of the IP signal and not only the integral IP. The module implements extensive processing tools with pseudo sections showing ERT or IP data, electrode positions with elevation, and full decay IP signals. The module is fully integrated with the GIS interface. Automatic filters help to improve the data quality and speed up the processing.

Inversion for both ERT/IP can be done in 1D or 2D using smooth, sharp, or layered models. The IP full decay data is modelled with a Cole-Cole or Constant Phase Angle parametrization.

 

Modelling and presentation to the customer is done with the well known functions of the Aarhus Workbench so integrating with boreholes, creating reports etc. is easy and only a few clicks away.

 

Key features

• Data processing with integrated display of electrode positions, pseudo section and IP decays

• Automatic processing of IP decays  

• Full current waveform and filters incorporated into the forward response when modelling IP data.

• 1D/2D Cole-Cole, Maximum Phase Angle, Constant Phase Angle and Integrated IP parametrization for inversion of IP data

• Smooth, sharp or layered inversion

• Integrated with the GIS interface

 

Import

ERT/IP data are imported using well-known data formats. In addition, the importer supports topography from an external topography grid or topography and electrode positions measured with GPS. Profile direction can be flipped. Data information is listed during import to make sure everything is correctly read from the data and electrode coordinate files.

 

Processing

The processing tool is integrated with the GIS interface. The processing window shows the data points at each focus depth along with pseudo section, electrode positions, ERT/IP decay curves. For processing the user can disable electrodes and the corresponding data points, single data points, IP decay curves and vertical soundings.

 

Inversion

Inversion of the ERT/IP data is performed with the AarhusInv inversion code. Full waveform IP data are inverted with Cole-Cole or constant phase parametrization. The model can be 1D or 2D with few-layered, many-layered and sharp models. Starting values for resistivity, thickness, constraints, chargeability, tau, and C can be individually changed for each layer, or optimal values can be chosen automatically. The inversion supports multi CPU cores with a high parallel efficiency. 

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