LiDAR and Drones: Accuracy and Quality Assurance
Air Inspect Australia uses drones equipped with LiDAR sensors to record a set of aerial data that can be used to produce high-resolution maps and 3D models of natural and man-made objects. The end result is high-level of accuracy, highly dense information about the conditions which reducing costs and man hours.
Originally, a method used in the the 1960s with helicopters, small aircrafts or satellites, first used by engineers and surveyors to map areas or measure depth. Nowadays the use of LiDAR with drones, allows for the collection of data to expand to areas that are hard to reach or near impossible to access.
The drone-based LiDAR sensors, scan the earth’s surface in a downward direction and measure the exact distance between the ground and the sensor at every point. Our team uses the DJI Zenmuse L1 – the point cloud generated from the data can yield 240,000 points per second at a vertical elevation accuracy between 50 – 80 mm. Other scanning sensors can count up to 1 trillion photons per second and outputting up to 5.2 millions points per second, (L2X Ouster LiDAR) and such data points can be generated within 5 mm accuracy.
The sensors can detect elevations of the earth’s surface through any kind of vegetation.
The result is an accurate map entailing the elevation information of every point. .
Why Aerial LiDAR?
Our team has completed aerial LiDAR capture for different projects at various specifications. LiDAR provides a fast, precise and a higher-performing alternative in delivering huge amounts of detail for large site areas, specific buildings, etc. In other words, drones equipped with LiDAR can gather accurate measurements of digital elevation and digital surfaces. Also, when combining photogrammetric techniques with LiDAR, you can achieve extremely accurate colour to point clouds and reality models.
Drone-based LiDAR Applications
Whenever the requirement is to assess terrains, LiDAR comes into play. And with rapid drone technological advances, such as symbiosis of sensor integration and visualisation software; data capturing, processing and generating point clouds are even easier. Simply put, the ability to monitor aerially offers significant advantages over any traditional/ manual on-ground methods in terms of speed, efficiency, accuracy and line of sight.
LiDAR aerial systems are the most suitable technology for mapping terrain. Previously, areas were measured manually using a theodolite and measuring rod. This time-consuming method is now replaced by a simplified, fully automated drone flight over the area. The LiDAR sensor measures the terrain and creates a digital map of the area with fine accuracy.
Feeder levels and crop yields can be calculated without the farmer driving long distances to the field or grazing area. Everything can be seamlessly recorded using a LiDAR equipped autonomous drone.
In large port areas, drone flights can be used to record the location, size, and number of containers, allowing port logistics to be optimised and the storage space to be used more efficiently.
Maintenance of utilities such as power lines, pipelines, railroad tracks, or wind turbines, is also an application where drone equipped with LiDAR sensor offer significant added value. It can be employed to detect structural damage, vegetation encroachment, integrity of the asset and other potential risks . This allows for substantial savings in costs and man-hours. For example, early detection of signs of damage can lead to predictive maintenance and thus save millions by avoiding potential shutdowns or breakdowns.
Sustainability of forests is vital, and the use of LiDAR-manned drones in forestry work are uplifting this ecosystem of trees and forest cultivation. Aerial surveys of the tree population provide valuable data on forest’s health and, for example, can help assess the damage after a storm.
Aerial LiDAR today
The nature of drone evolution brings about new ways and applications to integrate sensing technology. Subsequent usage scenarios can be derived, developed and integrated for better efficiency, reliability and accuracy. However, it is essential to ascertain quality LiDAR data.
Aerial LiDAR combined with photogrammetry techniques can produce extremely high measurements and data accuracy. It is more cost-effective and an ideal solution for large scale projects.