Camera calibration algorithms in vision based navigation systems

Calibration of intrinsic camera parameters is fundamental to vision based autonomous unmanned aerial vehicle (UAV) launching and landing. A pinhole camera perspective projection model is proposed. Both radial and tangential distortions are modeled. An improved two-step approach is examined by actual calibration experiments. Relative errors of parameters were all below 1%, and position accuracy is within 0.2 pixel. The proposed camera model and calibration method are appropriate for this application. Three major factors influence the accuracy of calibration process. They are camera model, precision of calibration pattern and quality of images. A method of practical camera calibration is realized.