地基大口径红外光电系统的联合辐射定标

考虑标准红外星定标方法无法测定地基大口径红外光电系统像元级的辐射响应度,进而导致对系统存在的非均匀性现象适应能力差的问题,提出了基于标准红外星与小口径黑体的联合辐射定标方法。该方法以标准红外星为外定标参考源,测定全光路系统的辐射响应度;以小口径黑体为内定标参考源,测定半光路系统像元级的辐射响应度;最后,结合内、外定标结果推算前端光学系统透过率,进而实现系统的全光路像元级辐射响应度定标。开展了自然星红外辐射特性测量实验,并与标准红外星定标方法进行了对比。结果显示:提出方法获得的目标最大反演误差为15.89%,而标准红外星定标方法在最理想情况下获得的最大反演误差为15.92%,表明提出方法的定标精度高于标准红外星定标方法。另外,提出方法能够测定全光路系统像元级的辐射响应度,克服了系统响应非均匀性的影响,进而提高了红外探测器的焦平面利用率,弥补了标准红外星定标方法的应用缺陷。

Combined radiometric calibration of ground-based large-aperture infrared photoelectric systems

When infrared standard stars are used in radiation calibration for a ground-based large-aper-ture infrared photoelectric system ,it can not determine the radiance responsivity of each pixel and shows a poor adaptability for non-uniformity of the system .To solve this problems ,a combined radio-metric calibration method based on infrared standard stars and the small-aperture blackbody was pro-posed .The infrared standard stars were taken as an outer reference source to calibrate the radiance re-sponsivity of the total optics ,and the blackbody was taken as the inner reference source to calibrate the radiance responsivity of the partial optics .Finally ,the transmittance of the front optics was calculated based on the inner and outer calibration results ,and the radiance responsivity of the total optics was calibrated in pixel levels .Several experiments were performed to inverse the illuminance of the infra-red stars .The results show that the maximum relative inversion error of the proposed method is 15 .89％ and that from infrared standard star calibration is 15 .92％ ,which means that the proposed method keeps more accurate than that of the infrared standard star method .Moreover ,the radiance responsivity of the total optics corresponding to each pixel is calibrated ,and the results indicate that the proposed method overcomes the interference of system non-uniformity ,improves the utilization ra-tio of the focal plane array and makes up the application defect of standard infrared stars .