Terrestrial laser scanning

The BGS has pioneered the use of terrestrial laser scanning for the monitoring of active earth processes. We use tripod mounted laser scanners that can be mobilised rapidly to make accurate measurements of landslides, coastal erosion and volcanic activity.

Since 1999 we have used a combination of scanners in different environments. We currently use two scanners. The first is a very long-range scanner that can make accurate measurements of the ground at distances of nearly 2000 m. Our second scanner is used at closer range (where measurements can be made more accurately and much quicker) at ranges up to 800 m.

Vehicle mounting system for scanning lowland areas.

Using our long range scanner to measure cliff retreat in Norfolk.

Scaffold mounted system with GPS control for estuarine monitoring

Used in combination with accurate differential GPS equipment the laser systems are used to support a number of applications that require detailed, accurate measurements of the ground surface. For each application, BGS scientists devise an appropriate survey technique. Just as importantly, we develop the best way to process the huge amount of information collected by each survey - we can collect up to ten million measurements and a thousand photographs in a single day! To make a model or record the data that the end user needs we often have to use sophisticated computers and software.

Volcano monitoring

Laser scanning is especially useful when we measure volcanoes - where we don't want to get to close the ground surface! The BGS has used terrestrial laser scanning to monitor the growth of a lava dome on Mount Soufriere on the Island of Montserrat. In May 2006, our measurements helped to support the decision to declare a volcano alert and evacuate the people of nearby villages and towns.

Monitoring an active volcano from a safe (1000 m) distance!

Measuring coastal erosion

We use our laser systems to monitor actively eroding sections of coast around England. The techniques we have developed are ideal for this application as terrestrial laser scanning is particularly suited to measuring vertical cliff sections. Measurements from a plane or satellite measure only the top edge of the cliff, whilst measuring them in the field is often very dangerous! Our technique enables the measurement of changes in the whole cliff section, (from a safe distance) that can be used to model how internal processes within the cliff slope affect coastal erosion.

3D model of the cliffs at Aldbrough, North Yorkshire measured in 2006. The image shows five million points, each measured to an accuracy of  25 mm.

For further information contact: enquiries@bgs.ac.uk