If you need to create an advanced aerial 3D map of something like a bridge, the ground underneath a dense forest canopy, or even the massive Christ the Redeemer statue in Rio de Janerio, you may need to use LiDAR.
LiDAR (Light Detection and Ranging) is a sensor technology that uses laser pulses to map out objects on (or protruding from) the ground. By combining light pulses with other aerial data, LiDAR can create a precise, 3D model of the Earth and its service, as well as terrain and elevation models.
Drones have made LiDAR technology even easier to come by, as LiDAR systems can be mounted on a drone as an “all-in-one 3D mapping device.”
The best drone system for carrying a LiDAR sensor
There are a handful of systems out there that are meant for drone-based LiDAR, but many of them don’t seamlessly integrate between the drone and the sensor, meaning a lot of work on your end to connect the two.
The easiest way to create a drone-based LiDAR system that’s as close to “ready to fly out of the box” as you’ll get is by mounting a ScanLook A-series LiDAR system to a DJI Matrice 600 airframe (or the Matrice 600 Pro).
The Pro version is an upgraded version of the Matrice 600; the Matrice 600 is not available from DJI directly in the U.S.
The DJI Matrice 600 Pro, which costs about $5,000, improves upon the Matrice 600 with improved flight performance and better loading capacity. With that, you’ll get an A3 Pro flight controller, Lightbridge 2 HD transmission system, Intelligent Batteries and Battery Management system.
It’s easier than the original M600 to fly out of the box, as pre-installed arms and antennas reduce time required for setup.
The drone has a modular design, which is great for mounting additional modules, whether you’re using a LiDAR system or something else. Should you decide to add one of DJI’s Zenmuse cameras, they are natively compatible. Or, you can choose to integrate it with your own third-party software or hardware (like the ScanLook A-series LiDAR system).
Some of the best, most common or most interesting use cases for drones and LiDAR
Mapping accident scenes to be used as evidence: A drone can map a car accident scene, and since it can be deployed so quickly, it can gather data in the immediate aftermath to allow for quick ground cleanup. And even if the accident happened at night, a drone can still do the job. Since LiDAR uses ultraviolet, near infrared light, it requires no external light.
Archeology: A drone with a LiDAR system can map an entire city in 3D in a few minutes, which would have typically taken traditional surveying methods years to complete.
Preventing flooding: A drone can fly over flood-prone areas and build a topographic model, which can help in risk assessment or emergency planning operations, as well as generating elevation maps that could indicate where drainage needs to be improved.
LiDAR or photogrammetry?
The Drone Girl has covered photogrammetry for drones in the past, and although the two technologies are somewhat similar, they are not the same.
Photogrammetry is not able to generate as exact results as LiDAR can (estimates suggest a difference of half a foot using LiDAR versus four feet with photogrammetry). LiDAR is also better if you need to measure the density of vegetation or the ground underneath it.
and it can also accurately measure where vegetation occurs, how dense the vegetation is and the topography of the ground underneath, and can yield extremely high density point clouds (100–500 points per square meter at a vertical elevation accuracy of 2–3 centimeters), according to PrecisionHawk.