地基大口径红外光电设备快速辐射定标

Fast Radiance Calibration for Ground-Based Large-Aperture Infrared Opto-Electric Equipment

在地基大口径红外光电设备的多目标分时观测中,为了消除环境因素对系统绝对辐射响应度的影响,在观测间歇快速地完成红外光电设备的辐射定标,研究了快速辐射定标方法。建立了定标实验的数学模型,确定了实验流程;以标准红外自然星为辐射定标源对红外光电设备的绝对辐射响应度进行了定标,并测量了大气透射率;对已知辐射照度的自然星进行观测,并通过定标实验得到的参数进行反演计算。数据表明,基于快速辐射定标方法的目标辐射照度反演最大相对误差为18.93%,定标实验占用时间约为4 min。作为对比,基于面源黑体定标光学系统并应用Modtran软件计算大气透射率的传统方法,反演最大相对误差为28.74%,定标实验占用时间约为17 min。结果表明,与传统方法相比,快速辐射定标方法的实验占用时间显著缩短,目标反演误差明显降低;系统不需要匹配面源黑体,大幅降低了成本。

In the multi-target observations using the ground-based large-aperture infrared telescope, in order to eliminate the influence of changing the system radiance responsivity caused by environment, and calibrate the radiance responsivity in short time during two observations, a fast radiance calibration method is discussed. A mathematical model and experimental procedures are set up. The radiance responsivity is calibrated, and the atmospheric transmittance is measured, based on the standard infrared stars. The illuminance of stars is inversed, which is known in advance, using the calibrated data. Data shows that the maximum relative error of inversion is 18.93% and it takes about 4 min to complete the experiment. As a comparison, the maximum relative error is 28.74%, and it takes about 17 min to complete the experiment, using the traditional method, that the radiance respoinsivity is calibrated based on the black body, and the atmospheric transmittance is calculated by Modtran. Results show that, compared with the traditional method,it takes less time to complete the experiment, and the relative error of illuminance inversion is smaller. The black body is not necessary, and it takes less cost.