Unmanned Aerial Vehicles, or Drones, have become inexpensive tools for not only high quality aerial video and photography, but also spectral and topographic mapping. Drones have become ubiquitous tools in the Natural Resources Industry. Applications in forest harvesting can be grouped into pre-harvest applications and post-harvest applications. Figure 1. Upper panels: Pre-harvest forest Stands; Lower panels: Post-harvest. Orthophotos (aerial imagery) from reconaissance flight

Recurrent mapping allows site managers to track tailings and overburden volumes and location, as well as mine pit geometry. Satellite Mapping has been mostly based on the photogrammetric processing of very-high-resolution, stereo optical imagery. Drone Mapping has also been mostly based on optical imagery (but with structure-from-motion algorithms). While a few satellite images may cover an entire mine site, 100s or 1000s of Drone photos may be needed to cover a large mine. A

There is a large number of Earth imaging satellites with high to very-high resolution cameras. The cell-size of their images generally ranges between 30 cm and 1 m . This is sufficient to map the smallest features in a cutblock. Figure 1. Forest cover mapping based on a satellite image of a cutblock in the Nechako-Bulkley region of British Columbia, Canada Combining all the different satellites, an area is often imaged multiple times per year. This is specially important fo