The time-domain induced polarization (IP) technique energizes the ground with an alternating square wave pulse. During current injection, the apparent bulk resistivity of the ground is calculated from the input current and the measured primary voltage. After the pulse has been transmitted, the IP effect is measured as a time diminishing voltage at the receiver electrodes.
SJ Geophysics Ltd. is a world leader in three-dimensional (3D) IP surveys and inversions. Our state-of-the-art IP systems match highly portable 3 – 10 kilowatt transmitters with our proprietary full waveform digital receiver systems, expandable to at least 32 dipoles. Data is interpreted in the field using powerful in-house software. Back in the office, the field data are inverted (using UBC-GIF inversion software) to produce 3D models of the subsurface resistivity and chargeability.
There are numerous advantages to 3D IP over older 2D techniques: increased survey design flexibility, higher data acquisition rates, more detailed results and lower overall cost (including savings in drill costs).
Applications
- Detection of disseminated metallic minerals
- Mapping of clay layers and sand deposits
- Soil or rock lithology
- Soil and groundwater contamination
- Interfaces between salt and fresh water
- Fracture location
- Borehole logging
