Research On Low-altitude Aerial Photographical Systems Based On Unmanned Aerial Vehicle

Aerial photogrammetry with micro UAV(unmanned aerial vehicle) is a new method of terrain detection. It is widely used in small or dangerous areas photogrammetry due to its advantages, such as flexibility, efficiency, low cost, little influence by the weather and the airfield, and the ability of obtaining high resolution images. As a good complement to aerial photogrammetry and spatial photogrammetry, it has got great development in recent years. Howeve r, compared with traditional photogrammetry, the low-latitude remote sensing system of UAV has certain disadvantages: large amount of small UAV images; large obliquity; irregular overlap etc.Compared with fixed-wing UAV, Rotor UAV is often not naturally stable and its load is small. So it has a little chance of developing in the field of photogrammetry. But with the improvement of the flight control system, the ability of hover and vertical take-off and landing make rotor UAV has been widely used in civil field. This paper studies and constructs an aerial photogrammetry system with the rotorcraft. And an experiment is made to validate its feasibility of mosaicing UAV images.The main contents of this thesis includes four parts as follows:(1) The characterisstics of UAV photogrammetry system are introduced, and the advatages and disadvantage of the system are analyzed.(2) Remote sensing digital image processing software such as Pix4 Dmapper, PIE-UAV and Photoscan UAV are analyzed, and the UAV data processing process used in our UAV photogrammetry system is determined.(3)A UAV potogrammetry systerm has been developed in our lab. The systerm mainly consists of four parts: synchronous trigger for camera, GPS data receiving and processing, IMUdata receiving and processing, wireless transmission based on Lab VIEW.(4) Measurement and experiment for UAV potogrammetry systerm are conducted in outdoor. The images matched and stitched accurately can be gotten using experimental date and our processing software.The experiment results indicate that the system based on Lab VIEW can realize the synchronization of different parts and the collection of data. A full image of the playground runway with coordinate information is obtained successfully by our system.