When flying a lidar mission, we would recommend using the following settings:
30-50% overlap
- With 50% overlap, this ensures every point we collect is seen from 2 flight lines. For missions that require high accuracy, 50% is recommended
Returns: Can differ from mission to mission. Lowering the returns will result in your project size being much smaller. If you need to penetrate vegetation and get accurate ground points, you should be using the most returns available on your sensor. However if you are just looking to quickly generate a DSM, then you may just want to use 1 return so you don't collect points you don't need with more returns.
Flight speed/height: Can differ from mission to mission but upper limit should be 10m/s. Flight height should generally be around 50-80m. For high accuracy its best to fly low and slow. We usually fly at 5m/s at 60m, however this takes more batteries and time to collect data. The higher and faster you fly, the quicker your mission will be. So if you are looking for quick collection you can always fly faster and higher, but your data will be slightly less accurate.
Repetitive vs. Non-Repetitive: Repetitive scanning follows a side to side pattern of scanning, this type of scanning is slightly more efficient and more precise. Non-Repetitive scans in a circular pattern which offers better coverage at more angles. Which to use depends on the flights setting, but it doesn't make a huge difference.
IMU Calibration (DJI mission planning setting): Rather than using this setting, we recommend planning your mission so you turn at least every 100 seconds during flight. This will save you a lot of time and batteries in the field, as well as a lot of time in post processing (boresite). This setting was made for the L1, so if your flight line is greater than 100 seconds, in the middle of your flight line it will go back and forth a few times to calibrate the IMU.
Turning will automatically calibrate your IMU, so its much more efficient to plan your mission to turn every 100 seconds. You can calculate the distance you can fly in 100 seconds with simple math. If I'm flying a mission at 5m/s and I want to figure out how long my flight lines can be, I would just go 5m/s multiplied by 100 seconds, which gives me 500 meters. My flight lines should be no longer than 500 meters.