Many good comments here. I'm a senior surveyor technician in the DFW region, I fly a sophisticated drone with photogrammetry and LIDaR capabilities, and I have to agree with what I've seen here. Many newbies to the drone industry are thinking they can simply purchase a drone and some inexpensive software and start producing survey grade photogrammetry. It just doesn't work like that. As has been stated above, no photogrammetry will replace the accuracy that an experienced field crew with proper survey equipment can provide, nor does LIDaR...presently. However, it can be a visual aid to those crews, technicians, engineers, and developers. It's a great tool to add to our toolbox. I would think that any engineer who designs any development with a simple aerial topograph with no ground truthing is taking a huge risk. He might want to up the amount on his insurance coverage for his work. One thing I tell all the newbies is this,... you have to learn the science. A UAV is nothing but a pick up truck carrying your equipment. Your clients aren't paying for you fly a really cool drone over their property. They're paying for the science. They're paying for what they hope is high grade imagery. Photogrammetry,or LIDaR both need to be top quality, ortho rectified, and as accurate as can be made to be. It takes experienced survey personnel a long time to learn how to collect that imagery and produce accurate , quality aerial maps from that imagery. I'm finding that this alone is turning many away from the engineering applications of the drone industry. There are plenty of other applications out there they can do and still make money. They just need to keep in mind that they need to learn some science behind whatever particular industry or application they intend to pursue. People are going to be reluctant to hire skateboard man to fly his drone around and take pictures. They want to know that your professionals and you know what you're doing.