I am interested in flying relatively large areas and taking vertical images, then stitching them together into a large aerial image. Ideally, I would also be able to ortho rectify these (basically like professional aerial photogrammetry) with known high accuracy (x,y,z) base points on the ground. I have seen some online services and software, but it seems to be oriented more towards a handful of pictures for creating panoramas, etc. I am talking literally hundreds of images. Does anyone have knowledge here on appropriate software, or even service entities that you could send your images to and have them processed?