比辐射星上定标器以太阳照射的漫反射板为参考光源,通过比值辐射计对漫反射板在轨衰变进行修正,实现光学遥感器的绝对辐射 定标及长期稳定性监测。比值辐射计辐射响应特性是影响在轨定标精度的主要因素之一。对比值辐射计辐射响应特性进行了 评估,获取了绝对响应度,并测量了响应非线性、非稳定性。结果表明绝对辐射响应度定标合成不确定度优于2.88%,非线性 优于0.93%,非稳定性优于0.52%,满足在轨定标应用需求。

The absolute radiation calibration and long-term stability monitoring of the optical remote sensor can be realized by the ratioing radiation on-board calibrator, in which the diffuser illuminated by the sun is used as the reference light source, and the on-orbit degradation of the solar diffuser is corrected by the ratioing radiometer(RRM). The radiation response characteristics of the RRM is one of the main factors affecting the accuracy of the on-orbit calibration. The radiation response characteristics of the RRM is evaluated. The absolute responsivity is obtained, and the response nonlinearity and response instability are measured. The results show that the uncertainty of absolute response calibration is better than 2.88%, the nonlinearity is better than 0.93%, and the instability is better than 0.52%, which satisfies the requirements of on-orbit calibration applications.