Historic Environment Division Lidar 2009

The Historic Environment Division (HED) acquired LIDAR over a six year period from 2008 to 2014 to assist with the interpretation and protection of archaeological landscapes in Northern Ireland.

A total area of approximately 130km2 was surveyed during this period across 39 sites. The data is provided “as is” under an Open Government Licence and is not supported.

LIDAR Airborne LIDAR (Light Detection and Ranging), also known as Airborne Laser Scanning (ALS) is a landscape survey technique that uses a laser beam transmitted in rapid pulses from an aircraft in order to accurately measure the distance between the aircraft and the ground. The laser pulses allow measurements to be taken in the order of 100,000 times per second with a vertical accuracy of 0.5cm which produces a dense cloud of points which can then be interpolated to produce an accurate three dimensional model of the landscape below.

In this instance surveys are supplied as either digital surface model (DSM) or as a digital terrain model (DTM).

For the DTM, buildings and vegetation have been removed and only ground returns have used to produce the model.

The technique can be particularly valuable for archaeological survey as it allows large areas to be surveyed accurately enough for the subtle topographic traces of archaeological features to be identified.

The data below was collected in 2009, the attached PDF coverage map shows the areas surveyed in that year.