I stumbled on the website of a researcher Paul Illsley from Nova Scotia that works on remote sensing and has a hobby of photography.  He has a nice website description of a balloon aerial photography system and techniques for working with different cameras, including a GoPro Hero.  The picture at left shows a model he generated in Photoscan from a balloon survey of a building.  He suggests a technique for removing the GoPro lens distortion that I will definitely have to try out.

Photo source: http://www.paulillsley.com/airphoto/systems/B.jpg