EDO7388 - A354 Dorchester to Weymouth; air photograph interpretation 1994

NRHE: A 1:2500 scale, level 3 photogrammetric survey was carried out by RCHME Air Photography Unit on an area of land on Ridgeway Hill above the Bincombe railway tunnel near Weymouth in Dorset. The area surveyed was 0.7 by 0.8 km in size and ran from the crown of the ridge southwards down the slope. The project was carried out at the request of Wessex Archaeology prior to a road building scheme, which threatened the area in question.The main objective of the project was to produce an accurate 1:2500 scale plan of the site in the form of an overlay to the Ordnance survey 1:2500 base maps. All archaeological features visible on aerial photographs were plotted. Features surviving as earthworks were copied from the OS base, except where accompanying crop marks provided new and previously unrecorded information. Plough levelled features were plotted as seen using the agreed conventions specified in the report. For the purposes of this survey, plough levelled features are defined as those which have been recorded on aerial photographs as differentially coloured or textured marks in bare soil, arable, grass or other vegetation.The plans were created using the AERIAL computer rectification software published by the University of Bradford. Field control was derived from OS maps of various scales and dates. This was due to the fact that some of the photography which showed the archaeology most clearly was of a very early date, and points visible as hard detail on the photographs were no longer plotted on the current edition OS maps. As a result residual errors did occasionally exceed the normally accepted level of +/- 2.5m, but when the separate plots were compared with each other and the base map, the accuracy was greater than that suggested by the residuals and well within acceptable limits.Since the intention of the project was to accurately record known features little new information was provided. For the barrow groups SY 68 NE 52 and SY 68 NE 96 some new information regarding their current appearance was added. Likewise the extent of the field system SY 68 NE 116 was increased.The archive created during this project is held by RCHME (Collection UID 932274) and consists of the plan and a short report.