Time domain EM (TEM) for resistivity/geological mapping in a hydrological context is one of the HGG groups' main research areas. The group covers all aspects that deal with TEM: Numerical modeling, instrument development, survey design and quality control, processing and inversion algorithms, and software design. The group has internationally recognized expertise in all the above areas. This expertise has been built up over decades of focused research and development.
In the 80’s and 90’s the focus was on groundbased TEM. In this period thousands of ground based soundings were carried out in Denmark as part the national ground water mapping initiative. Our group played an important role in the development of inversion algorithms and processing/inversion software. Equally as important was the setting of standards for survey design, data handling, and data quality. Among other things this led to establishment of a TEM test site. The test site has, over the years, been used to calibrate airborne and groundbased TEM instruments not only from Denmark but also from France, Germany, Switzerland, Australia and USA.
In the 2000’s to the present day the focus has shifted to airborne TEM. The airborne TEM system "SkyTEM" was developed with in the HGG group. Parallel to the development of the SkyTEM instrument research and development continues in many related areas: Processing and inversion algorithms (AarhusInv), software design (Aarhus Workbench) and quality control.