The Calibration Of UAV Video Geo-information And Live Processing Technology

With the development of unmanned aerial vehicle(UAV)technology,communication technology and computer technology,the live broadcast of video geospatial information becomes possible.In this paper,a set of video geospatial information live broadcast system based on the rotor UAV platform is built and the key technologies are studied and tested.On the basis of system design and integration,video-vamera geometry calibration,multi-sensor relative geometry calibration,airborne video frame extraction,POS aided orientation frame bundle block adjustment and POS data interpolation,high-accurate inner and exterior orientation elements are given to the video stream.The orientated video becomes a new type of survey product.This paper also carried out experiment to excavate the application potential of video geospatial information.The main work and innovation of the paper are as follows:1.A set of UAV video geospatial information live broadcast system is constructed.The keystone of multi-sensor synergy and the workflow of UAV video geospatial information live broadcast is introduced.The key technologies involved are analysed briefly.2.Theoretical research and engineering practice are carried out for video-camera geometric calibration.Undertake video-camera calibration by two workable and reliable methods respectively depending on 3D control field and LCD calibration field,and the calibration result is verified through experiment.3.On the basis of theoretical analysis of multi-sensor relative geometry(GPS antenna offset vector,IMU misalignment angle)in system integration,undertake IMU boresight angle calibration by “two-step” method.4.The frame extraction model of airborne video data is proposed.Several airborne video frame extraction methods are studied and their applicability is compared.POS aided orientation frame block adjustment is proposed to obtain high-precision exterior orientation elements of orientation frames,and its validity is certified by experiment.5.The problem of UAV POS data interpolation in complex flight course is solved by contrast experiment and analysis.The exterior orientation elements of video stream are interpolated by orientation frames to achieve the geospatial information registration of video stream.Experiments are carried out with the real geo-registrated data of test field in both emergency and routine mode to excavate the application potential of high definition video.