Until very recently, the methodology tended to rely on aerial photographic surveys conducted for alternative purposes, fiddly kites and weather balloons or on expensive charters of light aircraft and a photographer specially for the purpose.
The use of Unmanned Aerial Vehicle (Drone) Aerial Imaging technologies provides a game changer for archaeological research and streamlines data collection in the field.
Drones provide an efficient and cost-effective method of surveying and recording areas of landscape and individual sites quickly and flexibly, allowing for each survey to be individually tailored and adapted as they take place.
These surveys can in fact cost as little as 10% of the charter cost of a light aircraft
Drones can cover a 100m x 100m in less than 10 minutes at heights of up to 400ft (120m), providing the ability to survey a 25 ha area in an incredibly short period of time.
GPS technology allows surveys to be easily and accurately located in the landscape, incorporated into GIS software or onto any digital mapping software.
The raw photographic outputs are available 'live' as the flight takes place and are available immediately afterwards for initial evaluation and interpretation.
In fact, a survey can be 'live streamed' back to the office and the drone pilot 'directed' over the phone.
Images can be uploaded to the cloud on site and within hours, complex outputs can be created - available for analysis and interpretation pretty much by the time you return to the office.
The real beauty of using drones for archaeological surveys however is that multiple outputs can be achieved simply from one or two short flights over a specified area.
Panoramic, Overhead or Oblique Aerial Video or photography is available quickly and immediately.
The real game changer however are Photogrammetric 3d models, Orthophotos and Digital Elevation Models (DEM) which can be produced from pretty much the same raw output.
These aerial survey techniques take hours to produce what would normally take two people days to complete, if it was possible at all