Suitability of a Mobile Electromagnetic Induction Sensor for Archaeological Prospection

Prospection methods for archaeology focus on detecting very small features compared to other geophysical investigations. This requires very high density measurements of a sufficiently large area to map the buried archaeological remains and their context. In this research, the suitability of a mobile electromagnetic induction sensor is tested on an experimental field with buried metal tubes of 1ha and on a medieval site of 8ha. Both fields were successfully mapped in a 2 by 2m resolution and a smaller area of interest in a 0.2 by 0.5m resolution with the mobile sensor. The simultaneous recording of the magnetic susceptibility and the apparent electrical conductivity yields complementary information. Compared with a stationary grid measurement, apart from a slight shift in the driving direction the maps show similar patterns. For long surveys, especially the magnetic susceptibility suffers from drifts in time, which should be monitored and corrected.