Data Processing Services

Gravity | Magnetics

Mountain access with quads

Processing gravity data

Excel specializes in the reduction of gravity data in areas of rugged topography. Our proprietary terrain-correction software and extensive experience combine to provide the best terrain corrections available in the industry.

Our gravity modeling capabilities allow us to effectively evaluate the exploration significance of gravity over very complex geology. We provide both 2D and 3D modeling.

Some of the considerations we deal with during our processing are:

Basic corrections

• latitude correction,
• free air correction,
• Bouguer slab correction,
• terrain correction.

Density considerations

• constant density Bouguer and terrain corrections,
• variable density Bouguer slab and terrain corrections.

Available Gravity Datasets

• government and industry data currently for sale.

Datums

• NAD 27 vs NAD 83

Geoid undulations

Example of mismatch in elevations due to the use of two different geoids can be found at the Canada/US border in Alberta and Saskatchewan where there is a geoid offset of about 15 m.

Gridding Methods

• Kriging,
• minimum curvature,
• inverse distance,
• triangulation.

Filtering

• median filter,
• polynomial regression.

Processing magnetic data

We provide 2D and 3D ground gravity and 2D and 3D aeromagnetic data processing. We acquire and process about 10,000 km of ground magnetic data each year. In addition we process and interpret several hundred thousand kilometers of aeromagnetic data.

Our magnetic interpretations are integrated with available geological information to provide a complete assessment of the exploration implications of the aeromagnetic data.

In addition to basement relief mapping, Excel also provides very high-resolution versions of the standard aeromagnetic products such as:

• total magnetic intensity,
• vertical derivatives,
• near surface anomalies, and
• directional shaded relief.