How to create orthophoto from LiDAR and boresighted camera?

[helge-andre]

Hi,

I am looking for options to create an orthophoto, where I have available LiDAR point cloud (or DEM) together with images coupled with INS data.
What is then the best approach to generate an orthophoto, and what would be the requirements for image overlap?

I have processed orthophotos earlier just using nadir camera with loose reference to GPS data, but I assume there are other methods that can take benefit from the additional input data to speed up processing.

[Alexey Pasumansky]

Hello helge-andre,

One way is to align cameras, georeference the alignment result and then import external point cloud - build DEM from it (or import DEM directly) and use this surface for the orthomosaic generation.
For such approach common recommendations for overlap are applied (80% forward and 60% of side overlap).

If the exterior orientation information for cameras (XYZ coordinates and orientation angles) are known precisely, you can apply this information using the script and thus skip the alignment stage.
For the second approach overlap should be just sufficient to cover the complete area of interest, so could be even 20-30%.