Context 168 - June 2021

C O N T E X T 1 6 8 : J U N E 2 0 2 1 25 DIGITAL TECHNOLOGY safe inspection of structures, where vehicular access may be limited, and discovery of structural issues (such as fabric damage, loss, weathering, cracking and vegetation build-up) which can not be seen from the ground. Use of a drone within a protective, lightweight cage also provides a safe means of remotely inspecting a space within a historic building, deemed unsuitable for access, or analysing a section of fabric close up. Use of thermal imaging enables an assessment of depth of soft-capping and the highlighting of areas that may be susceptible to water ingress. Photography: providing a means of raising the camera height to capture a low-level aerial view of how buildings and archaeological features sit within the landscape, and video capture for use on websites and other presentational applications. The FutureTechnologies Review, published by the Geospatial Commission in 2019, highlighted the current, emerging and future trends in drone development. Although some of these, such as package delivery and passenger transport, are unlikely to impact the heritage sector, others could provide additional survey and remote inspection capabilities. These include tethered drones for safe flying within urban spaces; drone operations beyond visual line of sight, enabling their remote con- trol over longer ranges; autonomous mission configuration and management, enabling more automated flying and image capture; artificial intelligence to enable their safe flying within complex heritage structures; and machine learn- ing to automate the structural and condition analysis of the captured imagery. Further information https://historicengland. sensing/ Paul Bryan is the geospatial survey manager in Historic England’s building conservation and geospatial survey team. He is joint author of 3D Laser Scanning for Heritage; BIM for Heritage: developing a historic building information model and BIM for Heritage: developing the asset information model. One of 679 overlapping images captured by a drone during a geospatial survey of St Mary’s Church, Kempley, Gloucestershire. The 12th-century Grade I listed church, in the care of English Heritage, contains one of the most complete and well-preserved sets of medieval wall paintings in England. (Photo: Historic England) A DJI Phantom 4 Pro drone (centre) being used to capture low-level overlapping imagery suitable for inspection and survey applications (Photo: Historic England)