LiDAR Measurement: Process & Production
The project will be flown with United Photo and Graphic Services' ALTM Optech 167KHz LiDAR, with IMU and airborne GPS. A medium format (39 Megapixel) ROLLEI digital camera captures photography along the LiDAR flight path. Production typically involves LiDAR being flown on first available day with suitable weather at the required scale, with one or more base stations for airborne GPS. GPS files are processed to provide the trajectory of the plane and the LiDAR device. Range files are then processed, position files matched and corrected using overlap of range files. Final LiDAR measurements are corrected and classified into ground and non-ground measurements. DEM is created from the ground return points. Data supplied in specified format or as raster tiles and ASCII format files.
Quality Assurance Provisions:
- LiDAR to be calibrated at regular intervals prior to and post measurement
- Overlapping passes provide redundancy in the LiDAR measurement
- Sufficient Ground Control to provide redundancy and as a check on LiDAR data
- Fortnightly reports to be provided to outline status of project to client
- Digital photography also provides visual verification of LiDAR data