In 2012 during the case study Stonehenge four motorised fluxgate magnetometer systems were used in parallel for the first time. The newly developed eight-channel fluxgate magnetometer arrays towed by Quad bikes have been applied within the large-scale case study areas. Using sample spacing of 25 cm cross-line and 10 cm in-line daily coverage rates of over 20 hectares have been achieved. Thorough testing and development now permit the reliable use of magnetometry for high-resolution archaeological prospection at very large scale. This massive increase in data acquisition efficiency requires the formulation of best practice guides and standardized maintenance routines as well as a dedicated hardware service on standby. Continuous development and improvement of the data acquisition software and navigation solutions were fundamental for the success of this development.
A series of gradually improved magnetometer sensor carrier systems were designed, built and tested for fluxgate and caesium magnetometer probes. As a novelty all magnetometer systems now use digitizers that convert the analogue signal to a digital signal, which is recorded on ruggedized computers. Two different digitizer systems (EAL, Foerster PNC) were successfully tested and are now in routine operation. The within the LBI ArchPro consortium existing AMMS caesium magnetometer systems manufactured by PicoEnvirotec Inc. were converted to state-of-the-art analogue-digital converters for integration with the motorized LBI ArchPro magnetometer solutions. A first six-channel motorized CS magnetometer system was set up and successfully tested on the Neolithic site Altruppersdorf, within the Kreuttal case study area and at Carnuntum. The available caesium sensors and newly converted digitisers permit the formation of arrays supporting up to 20 total-field probes.
The instrument carriers for motorized systems were extensively used in the case studies and adapted where necessary. Routines for hardware maintenance and service were developed. Dedicated tow vehicles were acquired and specially fitted for the magnetometer systems. Exact positioning devices in form of RTK-GPS were integrated into the motorized survey systems. All acquired data is controlled and visualized by the developed data logging Software LoggerVis.