A Direct Calculating Method and Experiment of Absolute Orientation for Unmanned Aerial Vehicle Photograph

The traditional photogrammetric space similar transformation is used for Unmanned Aerial Vehicle (UAV) photograph digital positioning with the quite precise initial value. The new method based on the unit quaternions is presented. The rotation parameters are solved without iterative calculating and initial value. The absolute orientation is still carried out under the condition of the large angle photograph and the uneven ground control point, in which the non-linear angle parameters calculation is substituted by direct calculation. The direct calculating improves the reliability of the absolute orientation. The experiment result shows that the method is practicable and available.