Short for Light Detection and Ranging. LiDAR survey uses the well‐established principle of measuring distance by calculating the time taken by a pulse of light to reach a target and return. Airborne LiDAR does this with a pulsed laser beam which scans from side to side as the survey aircraft flies over a target area, measuring between 20 and 100 thousand points per second to build up an accurate, high resolution model of the ground surface and features upon it. The width of the scanned area is determined by the need to avoid obstacles that obscure the ground surface. The location of the data points is calculated using a Global Positioning System so that three‐dimensional coordinates are generated for modelling and analysis. Tests in landscapes rich in archaeological features show that careful use of LiDAR data can reveal previously unrecognized low‐relief features. Sophisticated modelling packages are also available to ‘clean up’ the data by removing the effects of tree cover to reveal a sub‐canopy land surface.
Subjects: Archaeology — Meteorology and Climatology.