DIGHEM - DIGital Helicopter ElectroMagnetics

DIGHEM System Specifications

Fugro Airborne Surveys’ helicopter electromagnetic (HEM) systems are the product of more than 30 years of experience, the acquisition of over 2 million line kilometres of geophysical data from every inhabited continent on the globe, and sustained research & development programs.

DIGHEM systems can locate mineral deposits and map surficial and bedrock geology in the top 150 metres of the earth. The systems are used to provide information on the conductive properties of the overburden and the bedrock for use in a variety of mining and environmental applications.

The DIGHEM^v HEM system uses multiple frequency electromagnetic fields to measure and map the electrical conductivity of the earth in three dimensions. Changes in the conductivity of the earth are caused by changes in geology, such as the presence of base-metal ore deposits, kimberlite pipes, geologic alteration zones or conductive sediment layers; by changes in groundwater location or salinity; or by changes in overburden type or depth. Simultaneous with the HEM survey the system uses a magnetometer to measure the earth's magnetic field, which can be interpreted to show changes in bedrock geology to a great depth.

While exploration for metallic mineral deposits has been the most common application of the DIGHEM systems, they have also been successfully applied to diamond exploration, geologic mapping, engineering applications such as overburden and permafrost depth mapping, sand and gravel location, soil characterisation and bathymetry. Environmental applications have included mapping of salt-water intrusion into the Florida Everglades, detection of buried metallic landfill and brine leaks from abandoned oil wells.

Concurrent with a DIGHEM survey, Fugro Airborne Surveys collects high resolution magnetic gradient and radiometric data.