Unmanned aircraft system (UAS) and photogrammetry software have matured together at just about the right time. This makes for possibilities that were unthinkable only a few years ago.
ERM used demo software downloaded from the Internet and images taken by a hobbyist with a Phantom 2 Vision+ UAS to create this photogrammetry video in only a few hours, learning curve included. Yeah, those are school buses. Imagine the possibilities.