| 摘要 |
A dither scanned IR imaging system is disclosed for achieving panoramic coverage. For complete 360 DEG azimuth coverate, the field of view is divided into eight sectors, each imaged by a separate objective lens upon a loose packed 2D photodetector array. The photodetectors are tight packed in the array columns while the columns are loose packed, being on centers spaced by integral numbers of photodetector dimensions (i.e., pixels). The image is dithered the distance between columns over the array by a pair of counter rotating IR refractive discs of wedge shaped cross section. A full-frame partial-sample of the image is taken each time the image advances one pixel until the image has been fully sampled. Tight packed arrays may also be employed if additional means are provided to partially sample the image. In achieving 360 DEG panoramic coverage, the imaging system provides a major improvement in performance over systems using a single linear array and avoids large mirror movements or large gimbal movements. An approach for employing a conventional tightly packed two dimensional photodetector array in a dither scanned imaging system is also disclosed which uses fiber optics to transform the image plane to the required loosely packed partially sampled configuration. Used in this manner the area array covers a wide field of view with many more pixels of resolution than the number of photodetectors provided in the array.
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