Not sure what kind of accuracy/resolution you would be going for but if check out "photogrammetry" can see how 3d reconstructions can be made from high resolution imagery taken from various angles, that combined with more traditional surveying of topography is possible. Also a quad or other aerial vehicle equipped with any sort of range detector like sonar or laser range finder could be used to create point clouds/rough topography maps but resolution there would be limited by GPS accuracy along with whatever range sensor is used. This isn't "typical" but any quad with a GPS and the right sensors could be made to do some kind of topographic maps.