Getting started

This short tutorial introduces to the basics of a complete ERTdesign project for multisource measurements through 3 quick steps.

Set the main survey parameters

The first thing to do to start an ERTdesign_ms project is to define the survey area. The most convenient way to do this is to draw a profile or an area - a polyline or polygon - in Google Earth TM and then to import the related KMZ or KML file. Don’t worry, however, if you miss a defined working area and you just need to perform a generic modeling task: ERTdesign_ms allows you to define simple layouts from interface.

Select the Survey Design icon of the Menu Bar to the left of the screen and set the configuration parameters in the corresponding panel.

Survey design panel.

Fig. 2 Survey design panel.

  • In the Survey area section select the KML or KMZ file containing the area for the design project. The layout of the area to be investigated will be shown on the map of the Survey design summary tab (Fig. 3).
  • In the Transceivers section, set the total number of boxes and/or the spacing for the electrodes of the Multisource boxes. The geometry of the electrodes is defined for each box in a reference system local to the P2 electrode.
  • In the TX combinations section specify the number of transmitting dipoles to be arranged in the two directions.
  • In the Run Generation section click on the Run arrow to generate the project. Appropriate advanced settings allow to make more flexible the sensors generation.

Check and modify the survey project

You can explore the details of the design project through the three main tabs of the software.

The Survey design summary tab shows the details of the set of sensors: the total number of Multisource boxes needed to cover the survey area, the total number of electrodes, the total number of measurements. This information is accompanied by a figure with the map of the sensors, which can be easily zoomed, panned or saved to file.

Survey design summary tab.

Fig. 3 Survey design summary tab.

The DOI/Vmn charts tab allows to display plots of the maximum sensitivity and depth of investigation for different combinations of receiving dipoles/transmitting multi-poles (left in Fig. 4) and to check how the Vmn signal changes when the background resistivity or the input current is modified (right section in Fig. 4).

Plots with maximum sensitivity, depth of investigation and expected Vmn signal.

Fig. 4 Plots with maximum sensitivity, depth of investigation and expected Vmn signal.

The TX/RX schedules tab displays the sheets with the coordinates of the electrodes of transceivers and with the details on n-poles measurements. In the bottom part of the tab you find the graphs with the measurements pseudo-plot and sensitivity plot for each n-pole.

Tab with sensors schedules and pseudo-plots.

Fig. 5 Tab with sensors schedules and pseudo-plots.

The analysis of the above parameters allows you to eventually redesign the survey, by modifying one or more parameters of the design panel, and to re-evaluate the project.

Save the project

Select the Load and save icon of the Menu Bar to the left of the screen to access the panel with the saving functions.

Load and save panel.

Fig. 6 Load and save panel.

The Save Project command allows you to save three files with the project details:

  • the KML file contains the locations of all sensors (Multisource boxes, electrodes, survey area). You can open this file in Google Earth TM , edit it and import it again into ERTdesign_ms using the command Load project to check how signals and sensitivities change with the new geometry of the electrodes.
  • The DATA file contains the complete list of electrodes and n-poles. You can use this file to perform modeling tasks within the ERTLab64 TM and ViewLab3D tools.
  • The TXT file contains the full configuration used to generate the project. You can open this file to reload the settings for a new survey design.

The Export configuration command allows you to save a CNFG file to load on the Multisource controller software to acquire field data.