Geophysical Survey Geophysical Survey offers a non-intrusive method of archaeological prospection and evaluation which can aid in the discovery of sub-surface archaeology. The main methods of geophysical survey are magnetometry and resistivity although a number of other techniques such as ground penetrating radar are also used. With risk minimisation a key concern for most developers, geophysical survey can offer a cost-effective way of testing large areas for the presence of sub-surface remains. However, geophysical survey can work with varying degrees of success depending on the type of geology and soil-moisture conditions present. The technique is particularly effective at locating past military and settlement activity including in-filled ditches, pits and hearths, agricultural features including field systems, and areas of industrial activity both ancient and modern. ARS Ltd offer a high quality and cost-effective Geophysical Survey service. The majority of the surveys undertaken are gradiometer surveys with all work overseen by our expert and experienced Geospatial Services team. All survey data is georeferenced via GPS and we are well-practised in delivering usable results on a very quick turnaround. We routinely use the geophysical results to assist in driving a question-led and targeted programme for any subsequent evaluation trenching work that may be required in order to move away from large-scale blanket evaluation trenching coverage.