Measured Survey

Date July 2009

Event ID 608674

Category Recording

Type Measured Survey

Permalink http://canmore.org.uk/event/608674

HY 5955 0873 Following a geophysical survey over the Brough of Deerness in 2006 a topographic survey was undertaken in July 2009. The survey aimed to record any earthworks across the site relating to the monastic settlement. To facilitate good data coverage in a relatively short amount of time, data was collected at 0.5m intervals, along traverses c2m apart. The data collection was then repeated at right angles to the initial dataset to increase definition across the features. The strimming of vegetation in the northern part of the site and the use of Trimble DGPS 5800 in backpack mode seemed to reduce problems encountered previously when using a detail pole in extremely tussocky grass.

The data were processed to generate a topographic model of the site and this clearly showed slight topographic changes caused by the presence of archaeological features, together with much broader topographic changes. To increase the clarity of the small-scale features background topography was removed from the data set, leaving only earthworks of archaeological interest. Analysis of the data showed a number of features that had not been identified by a previous survey by Durham University in 1986 and redefined other features which had been identified in the earlier work. The use of a GPS rather than a plane table in this difficult vegetation/terrain is clearly advantageous and has yielded useful results.

Archive: OCGU

Funder: University of Cambridge

Mary Saunders – Orkney College Geophysics Unit