• • What do McCall Glacier, caribou, and monster truck tires have in common?
  • Matt Nolan
  • November 08, 2013
• 

  Image above: At left, my orthoimage draped over the topography of the old and new Duckering Bldgs. At right, the topography is color coded by height..
  Photo Credit: Matt Nolan.

I have developed an airborne mapping system using unmodified digital SLR cameras that creates digital elevation models and orthorectified image mosaics that can be used to map anything from glaciers to caribou to truck tires with these specs:

• Spatial resolution: 5 cm to 50 cm ground sample distance (GSD, or pixel size); 12-25 cm is usually the optimal resolution in terms of flying hassle, costs, and file sizes
• Absolute x,y,z positioning with no ground control: <50 cm
• Absolute x,y,z positioning with ground control: ~2 cm (or as good as ground control)
• Random and systematic errors: <20 cm
• Orthoimage co-registration to DEM: Perfect (made with same data)
• Rapid Results: full resolution ortho of large projects (e.g., 4 GB DEM, 16GB ortho) can be processed with low-resolution DEM within 24 hours; smaller areas same day
• Standard Results: large projects require 3-4 days CPU time at full resolution with fast 32 CPU machine; smaller projects can be same day at full resolution

Other systems have been around for a while that can also do this, or something close to it. What’s different about mine is that it is affordable enough to make time-series of these maps, opening up brand new lines of scientific inquiry.