Geographic Information Systems (GIS)

Geographic Information Systems (GIS) are essentially database management systems (DBMS) capable of storing spatial information and which provide a map-based view of the data. Google Maps is a commonly used simple GIS platform but we also use a range of more specialised desktop and server-based applications for data capture, analysis and cartography.

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Much of our work now involves GIS including archaeological excavation and evaluation, desk-based assessments and transcription work with aerial photos and LiDAR. As most Historic Environment Records (HERs) also use GIS for the management of their heritage records, we also use GIS for HER enhancement work where we add to or enhance existing HER records. Our use of mobile GIS is invaluable here as it allows us to take HER information out into the field and, where necessary, capture new information.

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Where data does not exist in digital form, we can digitise points, lines and polygons from source plans and maps by georeferencing source material to a specified coordinate system such as the British National Grid, WGS84 or UTM zone. By attaching Global Navigation Satellite Systems (GNSS), we can use GIS to capture data in the field using mobile devices or on computers situated on boats for marine work.
 
GIS can also be used to undertake spatial analysis. This can include analysis of topographic survey data to quantify data quality or produce derived products such as hillshades, slope and/or aspect maps. Models of change can also be prepared using data from measured surveys including terrestrial laser scanning (TLS) and airborne laser scanning (ALS); depending on the scale, these can be used to monitor erosion and quantify impacts on a large scale, for example coastal erosion, or on a small scale, for example vehicular damage to earthworks. Spatial statistics can be used to investigate apparent patterns and correlations between features. Visual impact can be investigated using visibility analysis a method able to calculate the extent of potential visual intrusion and to inform an assessment of the effect this may have on archaeological sites and landscapes.
 
Maps and plans can be prepared to publication quality using GIS, including existing data or data captured for the purpose. Cartography is the discipline of conveying information using maps and our Graphics and Geomatics teams have considerable experience in producing high quality maps for archaeological purposes.

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GIS is a good way of publishing spatial information online and we regularly use Web Mapping Services (WMS), mobile GIS and platforms such as Google Maps to share our information with clients and the public, for example producing virtual tours of archaeological landscapes.
 
All our GIS and database work adheres to national heritage standards such as MIDAS Heritage and uses the National Monuments Record thesauri and the Inscription terminology lists maintained by the Forum on Information Standards in Heritage (FISH). This ensures our data is interoperable with other datasets and is fully compliant with English Heritage recommendations.