GCPs can be used to help constrain the SLAM data to mitigate drift
SLAM processing is available as an additional subscription for your ROCK LiDAR system. For further details and to explore your options, please contact the ROCK Sales Team.
Rock Desktop can incorporate GCPs in order to help constrain the SLAM trajectory. You can get these GCPs a number of ways.
- Collect with a Total Station or GNSS Rover. This is the traditional method and is the same for aerial LiDAR data captures.
- Users who collect aerial and SLAM data on a project site can generate GCPs using visible features like parking stripes, manholes, etc. from their aerial dataset. Here's how:
How to generate GCPs from your aerial point cloud data
- Process aerial LiDAR in ROCK Desktop and upload to ROCK Cloud.
- Set default CRS to WGS84 UTM Zone and ellipsoid height (m) in ROCK Cloud.
- In 3D visualizer, set point cloud view to Intensity.
- Adjust intensity slider for clear contrast.
- Place point measurements on clearly distinguishable ground features like parking and roadway striping, storm and sanitary manholes, valve box lids, etc.
- Save measurements.
- Export measurements as CSV.
- Download CSV.
After you have your csv of GCPs:
- Load SLAM data in ROCK Desktop and start SLAM processing.
- Choose capture method and process SLAM trajectory.
- Upload your GCPs to ROCK Desktop and select the corresponding WGS84 UTM Zone, the next step will be to match up your GCPs with your SLAM LiDAR point cloud data. Follow along with our video on SLAM GCP alignment:
GCPs USED TO ALIGN SLAM WILL NEED TO BE IN THE WGS84 UTM Zone COORDINATE SYSTEM
Other Helpful Links
How to capture and process SLAM data on the R3 Pro
Learn how to re-project SLAM data from meters to feet