What are the major advantage and disadvantages of UAVs (drones) for the remote sensing applications in comparison with manned airborne and satellite platforms? What are the advantages and disadvantages of multi-rotor drones compared to Fixed-Wing drones? What are weight and flight altitude limits for small UAVs according to FAA regulations. What is Structure from Motion (SfM) photogrammetric technique. When the structure from motion (SfM) and the Multi-view stereo (MVS) algorithms are applied to sequential drone images as in Pix4D and Drone2Map Software Packages. What useful data products can be produced..