摘要 |
A method of and apparatus for minimizing the polarization modulation effect of an optical scanner system which is in earth orbit and is scanning the earth, where the optical train of the scanner includes a plurality of optically aligned, rotatable, flat folding mirrors having incident angle normals in the same plane, with the mirrors serially reflecting an image acquired by the scanning of the system in orbit. The method includes the steps of rotating the most rearwardly disposed of the mirrors around its vertical geometric axis such that the reflecting surface of the mirror is perpendicular to the impinging image beam, and then rotating the mirror around its horizontal geometric axis such that the angle of incidence of the impinging image beam is of a preselected magnitude. This change in positional relationship results in a novel apparatus which minimizes the aforesaid polarization modulation effect.
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