Distortion calibration method of large-caliber optical camera

Abstract

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.

Description

technical field [0001] The invention relates to the technical field of optical measurement methods, in particular to a method for calibrating the distortion of a large-diameter optical lens. Background technique [0002] Photogrammetric optical lenses used in aerospace, aeronautical survey, astrometry and remote sensing technology have strict requirements on distortion, and their relative distortion is often less than 0.01%. The existing method for detecting optical lens distortion is goniometric method, which is to use a telescope to aim at a series of known points on the grid plate, and then measure a series of ω values ​​by the dial, and substitute each ω value into the distortion calculation The formula solves the distortion value of different field angles of the tested lens. The disadvantage of this method is that: during the measurement process, the telescope is used to align the grid plate's reticle and the dial is used to read the angle value, so it is difficult to ...

AI Technical Summary

Problems solved by technology

[0003] In order to solve the problems of low precision and many human factors in the existing goniometric method for detecting optical lens distortion, the present invention provides a calibration method for large-diameter optical lens distortion

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