MOTIONLESS FOCUS EVALUATION TEST STATION FOR ELECTRO-OPTIC (EO) SENSORS

摘要

A motionless focus evaluation test station is provided for measuring detector position error of EO sensors that do not possess dynamic focus capability. A positionally-fixed source emits EM radiation that diverges along an optical axis of the test station. Collimating optics collimate the EM radiation and direct it along the optical axis to the EO sensor. A positionally-fixed target is placed in the path of the diverging EM radiation nominally at the focal plane of the collimating optics. The target comprises a limiting aperture that exhibits an induced shift in optical focus at different positions along the aperture such that different positions on the target are imaged to different focal planes at the detector. The detector captures an image of the target that is blurred to either side of the spatial position that is optically conjugate to the actual detector position. A processor processes the image to measure the blur as function of spatial position to measure the actual detector position and output detector position error from a desired detector position.