  This paper presents OpenREALM, a real-time mapping framework for Unmanned
Aerial Vehicles (UAVs). A camera attached to the onboard computer of a moving
UAV is utilized to acquire high resolution image mosaics of a targeted area of
interest. Different modes of operation allow OpenREALM to perform simple
stitching assuming an approximate plane ground, or to fully recover complex 3D
surface information to extract both elevation maps and geometrically corrected
orthophotos. Additionally, the global position of the UAV is used to
georeference the data. In all modes incremental progress of the resulting map
can be viewed live by an operator on the ground. Obtained, up-to-date surface
information will be a push forward to a variety of UAV applications. For the
benefit of the community, source code is public at
https://github.com/laxnpander/OpenREALM.
