Distortion measurement and geolocation error correction for high altitude oblique imaging using airborne cameras

To measure the image distortion during the actual operation of an airborne camera, improve the accuracy of geolocation using airborne cameras, and reduce the influence of image distortion on location results, a distortion measurement algorithm based on overlapping remote sensing images is proposed, which attempts to overcome the image distortion caused by external working environment. A distortion measurement algorithm based on the geographical locations of the image coincident points is presented, and the distortion rate for the camera is calculated. To correct the positioning error caused by image distortion, the coordinate values of the target projection in the charge-coupled device coordinate frame are processed based on the distortion rate. The simulation results show that positioning accuracy decreases with increase in the distortion rate. When the distortion rate is 4%, use of the correction algorithm can improve positioning accuracy by 21%. The flight test shows that the maximum distortion rate measured by the algorithm for the experimental camera is approximately 9%. After correction, positioning error is reduced by 50 to 100 m, and positioning accuracy is greatly improved to meet the needs of actual engineering. (C) 2020 Society of Photo-Optical Instrumentation Engineers (SPIE)