Archives and Research

Aerial survey and remote sensing

Find out how we use aerial photography and high-tech equipment to record and research Scotland’s historic environment.

1 Overview

Our Aerial Survey and Remote Sensing Team is actively involved in research into airborne detection and documentation.

The team’s work provides unique insights into the past, drawing on traditional sources like aerial photography along with up-to-date techniques like 3D digital topographic modelling and hyperspectral imaging.

Our aerial survey work contributes to:

  • improved knowledge about Scotland’s historic environment
  • efficient survey methodology
  • knowledge creation and interpretation
  • conservation and management
  • outreach
  • leading the sector and partnership working in Scotland
  • international research on a significant scale

2 The team

Aerial Survey and Remote Sensing Team

Area of focus: Airborne approaches to recording and understanding Scotland’s historic environment.

We focus on two main strands of research. The first is improving knowledge in areas where the aerial perspective is especially powerful. For example, many of the known archaeological sites in the Scottish Lowlands have been levelled by agriculture. As a result, most of these are only visible from the air.

We also actively research emerging technologies that have the potential to aid us in our work programmes. These include:

  • 3D topographic data produced by airborne laser scanning, or LiDAR
  • digital photogrammetry
  • hyperspectral imaging, which could help us to record sites that are invisible to the naked eye
  • more speculative areas such as synthetic aperture radar 

Through our aerial survey and remote sensing work, we can better:

  • improve our knowledge base through the discovery of previously unknown sites
  • understand landscape changes
  • assess the impact of climate and coastal changes on the historic environment
  • inform understanding of the condition and management of sites
  • improve the efficiency of survey methodology

Aspects of this research activity also occur in the work of the Digital Documentation Team, Archaeology Field Survey Team and Heritage Directorate.

3 Partnerships and funding

Our funding comes from our core budget, with additional capacity through partnerships, both within Historic Environment Scotland and externally, and through external funding applications.

We draw on extensive professional networks and partnerships. These include:

We’re also active contributors to conferences, workshops and publications. We’ve attracted external funding, including from the Royal Society of Edinburgh, to explore a variety of topics ranging from the application of computer-aided feature extraction to the role of military intelligence aerial photography in conflict museums.

4 Projects

3D Scotland: Digital topographic data for archaeological survey

Accurate high-resolution height data is a powerful source for exploring archaeological sites and landscapes. Data is generated through ‘soft-bench photogrammetry’ or ‘structure from motion’ to extract height data from aerial photographs. Alternatively, we make use of airborne laser scanning data where it is available.

We look at how to use this data to record and understand earthwork sites which survive as humps and bumps in the ground. For example, at the prehistoric site of Braidwood in Midlothian we’re testing the limits of soft-bench photogrammetry to produce digital models to a remarkable level of detail.

The data produced allows the land surface to be visualised in multiple ways. These can be used to:

  • advance understanding of the monument
  • assess our techniques of archaeological survey
  • create digital outputs for wider audiences

Improving the detection of archaeological remains

Our ability to detect archaeological sites largely depends on visible cues in the ground surface or variations in vegetation. These can reflect buried features like ditches and pits that are otherwise invisible.

Hyperspectral and multispectral imagery greatly expand what we’re able to detect, however. These show wavelengths that are invisible to the naked eye, allowing us to ‘see the unseen’. This work will:

  • revolutionise our survey methodology by making visible vastly more archaeological remains
  • develop our use of satellite imagery
  • explore processing routines and tools for identification of features of potential archaeological interest
  • develop our capacity in remote sensing for applications including monitoring of landscape change

Research techniques

Our research activities draw on a variety of data sources and analytical techniques, including:

  • airborne laser scanning – recording the topography of the earth using an aerial laser scanning device
  • photogrammetry – the name given to a range of technical approaches in obtaining information about physical objects from overlapping stereo images
  • structure from motion – an imaging technique where 3D datasets are produced from two-dimensional image sequences
  • synthetic aperture radar – using radar and digital electronics to quickly provide high-resolution imagery for terrain modelling

5 Our Publications

The Aerial Survey and Remote Sensing Team’s work is widely published in books, papers and magazines. Its work frequently features in the media, and is regularly a topic of report in international conferences.

Recent books

Stichelbaut, B. and Cowley D. (eds.), Conflict Landscapes and Archaeology from Above, Ashgate, (2016).

Opitz, R.S. and Cowley, D.C. (eds.), Interpreting Archaeological Topography: 3D Data, Visualisation and Observation, Oxbow: Oxford (2013).

Cowley D.C. (ed.) ‘Remote Sensing for Archaeological Heritage Management, Proceedings of the 11th EAC Heritage Management Symposium’, Reykjavík, Iceland, 25–27 March 2010. Archaeolingua: Budapest (2011).

Recent papers

Cowley, D., ‘Aerial photographs and aerial reconnaissance for landscape studies’, in Chavarria Arnau, A. and A. Reynolds (eds.), Detecting and Understanding Historic Landscapes. PCA Studies 2. SAP: Mantua, (2015), 37–66.

Bennett, R., Cowley, D. and De Laet, V., ‘The data explosion: tackling the taboo of automatic feature recognition in airborne survey data’. Antiquity 88(341), (September 2014), 896–905.

McKeague, P. and Cowley, D., ‘From paper to digital, and point to polygon – the application of GIS in a national body of survey and record’. International Journal of Heritage in the Digital Era 8, (2013), 678–94.