Buckinghamshire Council Archaeology Service (BCAS) generic brief for an archaeological geophysical survey

Last updated: 18 August 2021

7. Fieldwork methodology

Accurate and precise surveying is essential and therefore preference is for a cart-based system with automatic RTK GPS logging, although, data collection using handheld gradiometers is also acceptable for magnetometer surveys.

As a minimum it is expected that:

  • All survey techniques will follow the guidance set out by the CIFA, Historic England, and the European Archaeology Council (EAC)
  • For handheld magnetometer surveys the standard survey resolution shall be no coarser than 1m x 0.25m (traverse lines 1m apart with data collected every 0.25m). For a cart-based system a higher resolution will be expected
  • The maximum survey resolution for earth resistance surveys shall be no greater than 1m x 0.5m (traverse lines 1m apart, data collected every 0.5m)
  • Instruments will be set up carefully to collect highest quality raw data to minimise the need for any post-survey processing
  • The location of survey grids will be plotted using a GPS system accurate to within ±0.01m relative to the Ordnance Survey National Grid