LiDAR (Light Detection and Ranging) data have proved effective for the location of subtle earthworks associated with archaeological features. Our analysis, using digital surface modelling, can help to identify archaeological landscapes virtually invisible on the ground.
Datasets for the UK are available from the Environment Agency and have proved exceptionally useful for archaeological assessment and prospection. Archaeological Surveys process raw data and can provide interpretation plots, contours and digital terrain models.
'Bare earth' models have produced exceptional results for wooded
landscapes. Subtle earthworks are often visible in the data where no
other form of survey could produce effective results. LiDAR was used to
compliment a recent geophysical survey of a Roman villa in the
Cotswolds and revealed a previously unknown Roman road running for 800m
through deciduous woodland.
Combining LiDAR data and magnetometry results also proved effective
on a Roman town adjacent to a flood plain. Where long linear magnetic
anomalies of uncertain origin were shown to correlate with surface
depressions, it was possible to state that they were unlikley to be
Roman in origin as much of the archaeology was buried below alluvial
LiDAR can provide a stand alone solution to archaeological
assessment and prospection where earthworks are expected or can be used
in conjunction with geophysical survey or analysis of aerial
LiDAR data analysis can prove highly cost effective in removing or
reducing the need for ground-truthing where earthwork complexes are
surveyed using magnetometry. It can be difficult to separate positive
magnetic anomalies relating to former ditches from those caused by
magetically enhanced soil within earth banks. Combining the magnetic
data with LiDAR can help to confirm the nature of features located and
indicate whether they are still extant.