Airborne Laser Scanning (ALS)

The TOPODRONE LiDAR is designed to perform airborne laser scanning (ALS). To perform this procedure, you will need a drone that supports the correct installation of the TOPODRONE LiDAR and is capable of following a planned flight path. One such drone, for example, is the DJI M300/350 RTK.

TOPODRONE LiDAR ALS rules:

1. Neighboring spans (hereinafter for simplification - scans) should have a lateral overlap of 30% or more. 2. 
2. Scans should be parallel to each other
3. The drone must follow neighboring scans in forward and reverse directions
4. The movement speed of the drone with the TOPODRONE LiDAR on the main section of the VLSALS should be constant
5. The distance from the TOPODRONE LiDAR to the ground surface shall be constant
6. To obtain correct ALS data, it is recommended to take at least two scans
7. Use original propellers to reduce vibration
8. Do not fly in squall winds or during precipitation to reduce noise
9. After initializing the TOPODRONE LiDAR and taking off, perform a calibration maneuver before the main ALS section of each flight
10. If the flight takes more than 30 minutes, it is recommended to perform the calibration maneuver again when the session time reaches 30 minutes after turning on the TOPODRONE LiDAR.

ALS and the terrain elevation:

At insignificant height differences at the ALS location (up to 10 meters) it is allowed to fly the drone with TOPODRONE LiDAR at a fixed altitude (AMSL). The altitude of the drone flight is set relative to the altitude of the takeoff point. Accordingly, for the main part of the flight, almost any software can be used, allowing to set the flight on a circle (to perform the calibration maneuver), as well as to set the distance between parallel passages. 
If altitude differences at the ALS location (10 meters or more) are exceeded, it is necessary to use software that supports the “elevation envelope” (AGL) function for ALS route planning. The most convenient way to plan such routes is to use UgCS Expert software.