The geophysics team at English Heritage recently hired a JCB utility vehicle to help undertake a detailed survey of the ground surrounding Stonehenge. This ground penetrating radar (GPR) analysis has resulted in highly accurate 3D mapping of the fine detail of objects down to a depth of 2m.

The radar image was built from directional and depth data reflected from any solid buried objects, and global positioning system (GPS) antennae enabled measurements to be located at 7.5cm intervals.

To avoid ground surface damage, multi channel radar equipment with the GPS unit on top was towed by a 4×4 JCB vehicle, hired by English Heritage from SMH Quads at nearby Great Wishford. The topography of the site includes some deep ditches, and the vehicle was able to traverse them without any risk of wheel spin.

To avoid visitor disruption, the survey began each day in the early hours before the site opened to the public, and then continued after six o’clock when it had closed.