LiDAR, or Light Detection and Ranging, is commonly used to generate accurate, precise (and often very detailed) survey data and point cloud models across a range of geo-survey, construction and infrastructure projects. What is LiDAR exactly? The US National Oceanic and Atmospheric Administration defines it as…
a remote sensing method that uses light in the form of a pulsed laser to measure ranges (variable distances) to the Earth. These light pulses — combined with other data recorded at the time — generate precise, three-dimensional information about the shape of the Earth and its surface characteristics.
NOAA
Most LiDAR capture is carried out at ground level, usually with static, fixed scanners attached to a tripod, or using mobile scanners on a vehicle. Large airborne LiDAR scanners fitted to manned aircraft are used for wide area mapping and extended survey work, mostly by government agencies or research institutions.
Drone-BAsed LIDAR
But in between ground-based LiDAR and the long-range scanners used on aircraft, there is a growing need for LiDAR data capture from the air at closer ranges, and over areas that might not be that accessible or easy to reach with conventional ground scanners.
This is where drone-based LiDAR comes into its own. But there’s a problem:
LiDAR scanners, even ones designed for UAV use, are still quite heavy — not to mention expensive! Most require a heavy-lift drone, able to carry payloads of 4kg to 6kg, or more. When combined with the weight of the drone itself, you’re looking at an overall take-off mass of 10kg to 12kg, which unfortunately exceeds the current max take-off limit for unmanned vehicles set by the Civil Aviation Department (CAD) in Hong Kong.
The maximum take-off weight for UAVs in Hong Kong is currently 7kg.
However, Dronesurvey Asia has a solution. We are pleased to have partnered with Red China Geosystems, and together we have flown a high resolution RIEGL miniVUX-1UAV aerial LiDAR system on an unmanned aircraft that falls within CAD weight regulations for the first time. Red China Geosystems is the Greater China Distributor for RIEGL laser measurement systems. They provide and support the entire range of RIEGL products in the region.
No doubt certain enterprises in Hong Kong have been operating LiDAR systems on larger drones with a take-off mass exceeding 7kg, but they are clearly flying without a CAD commercial operation permit, and probably without appropriate insurance cover. We are now able to fly within the current weight limitations, and deliver quality data without compromising air safety or regulations.
Riegl UAV
There are a number of RIEGL drone-based scanners available, all of which can deliver exceptional results across different scenarios. Probably the best all-round scanner for survey-grade aerial scanning is the RIEGL VUX-1UAV, with up to 500,000 measurements/sec, and a scan rate up to 200 scans/sec.
However, because of the weight restrictions outlined above, we can’t currently fly this scanner in Hong Kong. So instead we’ve been getting good results with the smaller RIEGL miniVUX-1UAV, fitted to a DJI Matrice 200 system.
Together, this combination comes in at under 7kg, and allows us to deliver excellent results over steep and/or inaccessible areas. The miniVUX-1UAV can make up to 100,000 measurements/sec, and has a scan rate up to 100 scans/sec.
Why Riegl?
Based in Austria, RIEGL is renowned the world over for the quality, reliability and precision of their laser scanning and measurement equipment. With 40 years experience in research, development and production of laser rangefinders, distance-meters and scanners, RIEGL delivers proven innovations in 3D laser scanning and acquisition.
The combination of RIEGL’s state-of-the-art hardware for terrestrial, industrial, mobile, airborne, bathymetric and UAV-based laser scanning with equally innovative software packages for data acquisition and processing delivers powerful solutions across a multitude of applications in surveying and GIS.
A key advantage of RIEGL scanners in the Hong Kong situation is their ability to scan “through” vegetation, and accurately map the underlying topography of the landscape. RIEGL’s multi-target resolution is the basis for penetrating even dense foliage, and a unique Waveform-LIDAR technology allows for echo digitisation and online waveform processing.
On top of this, RIEGL have recently announced the new miniVUX-2UAV, which doubles the measurement rate up to 200,000 measurements/sec, all in the same lightweight package, making it ideal for scanning dense, steep areas in Hong Kong.
We hope to have this unit available here very soon. Contact us for details.
The Complete LiDAR Solution
Laser scanning utilising unmanned airborne platforms allows you to acquire critical, accurate and detailed data in hard-to-reach areas (of which there are many in Hong Kong) while offering an excellent cost-to-benefit ratio across numerous applications.
With this new line of survey-grade airborne scanners developed specifically for UAV-based applications, we with Red China Geosystems are in a position to revolutionise LiDAR scanning capabilities in Hong Kong.
Get in touch today for a no-obligation estimate on your next project.
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