UAV LiDAR – making the invisible visible!
Imagine discovering ancient Mayan cities hidden for centuries beneath dense foliage in the northern jungles of Guatemala. Sounds like a scene from Indiana Jones and the Temple of Doom. But thanks to a remote sensing and mapping technology called LiDAR (short for Light Detection and Ranging), archaeologists were able to digitally remove the thick Guatemalan forest canopy to reveal a vast network of more than 61,000 Mayan structures including pyramids, buildings, canals and highways.While LiDAR is revolutionising archaeology, closer to home, Fox and Associates’ new UAV LiDAR technology is raising the bar for those needing highly accurate and detailed surface modelling and mapping services.
LiDAR sends bursts of laser pulses, from the air down towards the ground, to collect measurements that are used to create 3D models and maps of objects and environments. However, for the uninitiated, there is LiDAR and then there is LiDAR!
Most LiDAR technology currently available in New Zealand fire out laser pulses and only use the discrete laser returns this being the thing the laser pulses hit. So if the pulses hit the top of a tree, the measurements collected will give you lots of detail about the top of the tree but provide poor detail on what lies beneath the tree.
Fox and Associates use a unique Waveform-LiDAR technology, allowing echo digitization and online waveform processing. This means the pulses penetrate dense foliage better giving a more complete picture of the foliage and ground. A side benefit is out LiDAR unit is even optimised for the measurement of snowy and icy terrain.
The LiDAR data can then be used to create surface models that strip away the foliage to give accurate detail about the landscape, ground surface and ground condition. This provides vital information for people who need to model the ground for design purposes; whether that’s mapping flood risk, monitoring coastal erosion, assessing carbon stocks in forests or designing structures and landscapes for tree-covered sites.
The LiDAR data can also be used in the form of a point cloud to map structures, features and objects such as buildings, bridges, roads and infrastructure or in the case of the intrepid archaeologists, uncover entire cities, in pinpoint 3-dimensional detail.
With our new RPAS (Remote Piloted Aerial Systems) UAV and Part 102 CAA Operator certification, we can map sites up to 25 square kilometres in perfect detail of plus or minus 30 millimetres, depending on the level of accuracy required.
Our investment in UAV LiDAR is about making the invisible visible; removing assumptions and uncertainty and giving people tangible and accurate information so they can make decisions based on the real situation.
To learn more about the Mayan discovery, read these articles on the NY Times and National Geographic