Applications of conventional and non-conventional GPR systems in the Viking remains of Torget

The results of a geophysical survey conducted in the main square of Trondheim (Norway) are presented. Trondheim is one of the oldest major cities with urban settlement dating back to the Viking ages, and below the current square archaeological test excavations have revealed preserved cultural layers; the oldest from the 10^th century. We carried out a geophysical survey in the South Eastern quadrant using three different GPR systems: a reconfigurable prototype stepped frequency GPR, a pulsed GSSI GPR system and a 3DRadar stepped frequency device. The selected area represents a natural test site. In fact, the main topic of our geophysical campaign was to recognize, in an urban context, the presence of known archaeological remains and to compare the performances of the prototype device with two traditional GPR devices. Comparable results have been achieved, as it will be shown.