If you click here then you will get to a BBC report explaining how archaeologists from the University of Southampton have built up a detailed plan of Old Sarum (Salisbury) using modern techniques. These included “magnetometry, earth resistance, ground penetrating radar and electric resistivity tomography, which uses electrodes to probe underground”. No actual digging was undertaken.
As such, it fits in well with what we were talking about in history society yesterday. The past is not fixed, and technology is increasingly being used to develop our understanding.