Main requirements
The YellowScan systems are integrated in a way that the IMU and the scanner are maintained aligned even when dismantled from the UAV platform. Nevertheless, we recommend a yearly check to validate that the calibration angles remained stable.
If the unit has experienced a brutal shock during a crash or a hard landing, the system will likely need to be re-calibrated as the shock might have introduce a shift to the existing alignment. To complete the yearly health check calibration process, YellowScan users will be required to fly over an area, adopting a certain flight plan as described below and transferring the data back to YellowScan support team who will be checking the calibration angles.
The calibration process produces the 3 attitude angles required to correct the alignment of the IMU relative to the scanner: roll, pitch and yaw. These angles are measured by comparing how 3D features display from one flight line to another. The calibration process therefore requires that:
- the calibration contains 3D objects such as buildings (ideally with double pitched roofs)
- the flight plan needs to be conducted according to a certain pattern (see below)
- The flight altitude will depend on the system, as indicated in the table below:
| Mapper | Mapper+ | Ultra | Vx Serie | Explorer | Voyager | |
| Red path AGL | 50m | 70m | 60m | 60m | 70m | 70m |
| Blue path AGL | 60m | 90m | 80m | 80m | 90m | 90m |
For Mapper+ and Explorer : Several control points on flat surfaces, ideally intensity targets should be picked-up over the flown area with cm level accuracy method (RTK rod or theodolite). This will help the calibration process.
To complete the calibration flight plan, adopt the LiDAR Standard Operative Procedure as per a normal flight. This should include the IMU initialization method.
Best calibration angles are generated from flying over a double pitched roof building (see image below) following the flight plan described next.
