A Calibration Method for Fish-Eye Camera of Lunar Rover

A two-step method is proposed in the paper for calibrating fish-eye camera of Lunar Rover accurately.First,the spherical projection equation is used as the fish-eye camera projection model,and the relation between spherical projection and perspective projection is modeled.Then using the property that the spherical projection of a line is ellipse arc,the coordinates of principal point of photograph and spherical radius are calculated.Second,by calculated parameters,spherical projection is transformed to perspective projection.And intrinsic parameters of fish-eye camera are calibrated.New calculated parameters are used to supersede old ones to calibrate iteratively the intrinsic parameters.The process stops until the calibrated result is converged to a design value.An experiment is carried out to validate the method in the paper.