APPLICATION OF UAV AERIAL PHOTOGRAMMETRY FOR ROCKFALL DISASTER SURVEY

As a new method to obtain geographic information, UAV(unmanned aerial vehicle) has attracted a lot of attention. Compared with professional photogrammetry fixed wing UAV and large multi-rotor UAV,small quad-rotor wing UAV is more flexible, more maneuverable and more economical to survey the topographic of single disaster and micro-region. In allusion to the particularity of the working environment for rockfall survey, this article studied the influence of flight height and the angle of camera to the accuracy of data acquired by mini quadrotor UAV when it's impossible to set GCPs(ground control points) in field to optimize the data. The results indicated that:(1)DJI phantom 3 UAV can improve the horizontal accuracy in 63%,vertical accuracy in 7%when decrease the flight height from 150m to 90m, and improve the horizontal accuracy in15%~69%,vertical accuracy in 6%~9% when keeping the lens vertical. (2)In the context of a rockfall survey case in Shandong province Zibo City, author obtained the topographic data by UAV,then analyzed the 3-D numerical simulation of the rockfall movement utilizing Rockyfor3D program, the result showing the rockfall movement will threat the power grid and road has certain significance for prevention and control work for rockfall disaster.