The cart-based ATV towed survey was undertaken using a five-sensor array deploying Sensys FGM650/10 sensors mounted at 1m intervals (1m traverse interval) onto a rigid frame. The system was programmed to take readings at a frequency of 100Hz (allowing for a 1-2cm sample interval) on roaming traverses (swaths) 5m apart. These readings were stored on an external weatherproof laptop and later downloaded for processing and interpretation. The system was linked to a Leica GS18 Real Time Kinetic (RTK) differential Global Positioning System (dGPS) outputting in NMEA mode to ensure a high positional accuracy for each data point. MonMX (Sensys Ltd) software was used to collect and export the data. Anomaly GeoSurvey v1.12.3 (Lichenstone Geoscience) and QGIS v.3.34.6 software was used to process and present the data respectively. A range of magnetic anomalies have been recorded by the survey including several anomalies of modern origin relating to the former use of the south-western part of the site during World War II as an airfield (Boxted). Several former field boundaries, cultivation trends, the base of a former electricity pylon and buried services have also been recorded. Although no anomalies of definite archaeological potential have been identified by the survey, excluding any remnants of the airfield infrastructure, several anomalies have been categorised as being of uncertain origin, where a possible archaeological origin cannot be disregarded. These interpretations are made based on their correlation to previously recorded undated cropmarks recorded on the Colchester Historic Environment Record. However, in all instances a non-archaeological origin is considered most likely. It should be noted that the bedrock and superficial geology may not be particularly conducive for clear results. This may explain the low magnitude of some of the anomalies including the vague response over the cropmarks. Consequently, it is considered possible that there may be archaeological features present (particularly those that may be small, shallow or discrete) that cannot be detected by the survey, although it is considered likely that any extensive or dense archaeological activity or wider settlement activity would have been detected. Overall, based solely on the results of the geophysical survey, the archaeological potential of the site is therefore assessed as low for remains of pre-modern date but high for remains associated with the former Boxted Airfield.
Eloise Turner (Wed,) studied this question.