The invention relates to the field of optical measurement methods, in particular to a
distortion calibration method of a large-
caliber optical camera. The
distortion calibration method of the large-
caliber optical camera resolves the problem that an existing angle measurement method is low in accuracy and has too many artificial factors. The method comprises the steps that a standard aperture
mask is located at the
image plane of a tested camera, the center of the standard aperture
mask and the
principal point of the tested camera coincide, a
theodolite is located at the object space of the tested camera, and the rotary axis of the
theodolite and the
entrance pupil center of the tested camera coincide; a
reticle of the
theodolite is illuminated and is imaged through the tested camera; the image of the
reticle and the scribed line of the standard aperture
mask are observed by using a reading
microscope, the theodolite is rotated to enable the
reticle to be aligned at a scribed line pressing line of the standard aperture mask, the theodolite records spatial coordinates of each specific point and then transmits the spatial coordinates to a computer, a two-dimensional grid chart is automatically obtained in a fitting mode by two-dimensional grid chart fitting
software in the computer according to the spatial coordinates of each specific point, and
distortion values of different field angles of the tested camera are worked out. The distortion calibration method of the large-
caliber optical camera can automatically generate the two-dimensional grid chart and the distortion values, is high in measurement accuracy and is not affected by artificial factors.