Surrey Heath Borough Council is using airborne laser mapping to help flood alleviation works on ChobhamCommon – the largest National Nature Reserve in the south-east of England. The LiDAR data from Blueskyhas been captured using aircraft mounted sensors to provide centimetre accurate land elevation data. This isused to model the flow of water across what is thought to be one of the finest remaining examples of lowlandheath in the world.
Using the Bluesky data Surrey Heath has identified the potential to reinstate some medieval ponds and hopesto attenuate flood water coming off the common into nearby villages in this desirable area of the Londongreen belt.
“I was blown away by how detailed the data was,” commented James Rutter, GIS Manager at Surrey HeathBorough Council. “I’ve not actually used LiDAR data before but am extremely impressed with the quality,density, coverage and accuracy of the height data. I have also been impressed with the service and supportfrom Bluesky.”
“Using the data we have been able to run a watershed analysis on this hugely important and sensitive site.We have identified at least one medieval bund; used to retain water, in Glovers Ponds on the common andwe hope to be able to reinstate this and other historic drainage pools to attenuate flood water coming off thecommon. We are also hoping to use the LiDAR data to work out cut and fill volumes for the work to reinstatethe bund in order to gain an accurate understanding of the project costs.”
The Surrey Heath data was captured using Bluesky’s state of the art airborne mapping system. The LiDAR(Light Imaging Detection and Ranging) system uses aircraft mounted lasers to accurately determine thedistance between the sensor and the ground or other targets such as buildings and vegetation.
Bluesky uses an Optech Orion M300, the highest specification instrument being operated from a UK base.This allows for the capture of LiDAR data at a higher point density and at a better accuracy than othersystems due to an increased pulse repetition rate. The system also includes the latest available technology inglobal positioning and inertial measurement for improved accuracy sensor positioning.
In what is a world first, the Bluesky system is also fully integrated with a photogrammetric survey camera(the CS-10000) and a thermal infra-red imaging system (the CS-LW640), to allow the simultaneous captureof truly co-registered data where required.