Getech maintains the world’s most extensive commercial library of gravity and magnetic data. The continental-scale compilations of Africa, South America and Southeast Asia, completed in the 1990s, are now augmented by regional compilations of Europe, Central Asia and many other country-specific datasets.
All of these compilations involved the data processing and QC skills of our team of geophysicists.
The key techniques are as follows:
- Digitising vintage contour maps or archive listings
- Data validation
- Checking and/or applying standard corrections (e.g. Bouguer correction, terrain correction, IGRF correction, etc.)
- Consideration of different gridding algorithms
- Upward and downward continuation
- Cross line and micro-levelling
- Using enhancements and derivatives for QC
- Linking magnetic surveys of different vintages
- Generating grids and line data in any format for loading into industry software (e.g. Petrel or ArcGIS™)
Before and after line levelling of magnetic data
Derivatives of gravity and magnetic data (e.g. high- and low-pass filters) are critical for quality controlling the processing of surveys and, of course, are generally the starting point for interpretation studies. The in-house development of specialist software (e.g. Geosoft’s GXs and our own internal GETgrid software) allow us to apply specialist algorithms that are not addressed by third-party software.
The team is at the forefront of the specialist skills required for processing satellite altimetry data into gravity data. Numerous Research and Development studies over many years have generated a team of in-house experts, who often give talks and presentations at industry conferences and meetings.
Data processing is critical for ensuring that geophysical surveys, whether shipborne or airborne, are in a suitable state and format to be interpreted.
Archiving large regional databases of gravity and magnetic data on behalf of clients is another important activity that our team manages.