为满足星载多角度偏振辐射计六孔径同时定标及全光路定标的要求,根据多角度偏振辐射计的光路特点和结构约束设计了六出孔椭球形积分球定标源,并对积分球辐射输出的一致性﹑均匀性及偏振特性进行了检测。其中,一致性的检测采用定标后的光谱辐射计直接测量;均匀性的检测考虑积分球出口小,采用了透镜加光阑扫描的方法;偏振度的检测使用了根据马吕斯消光定律设计的线偏振检测仪。实验和检测结果表明,采用的检测和数据处理方法提高了系统的信噪比和测量的准确性。积分球成对开孔输出一致性优于99.5%,面均匀性优于99%,偏振度低于1%,这些结果满足多角度偏振辐射计的辐射定标需求。
In order to calibrate the six apertures of a multi-angle polarizing radiometer synchronously and to meet the need of full beam path calibration, a six-hole ellipsoid integrating sphere calibration source was designed according to the optical characteristics and structural constraint of the polarizing radiometer. Then the consistency, uniformity and polarization of the integrating sphere output were tested. In the test, the consistency was directly measured by using the scaled spectral radiometer, while the uniformity was detected by using the scanning method combined a lens and apertures in con- sideration of the small outlet of the integrating sphere. Furthermore, the degree of polarization was detected by a linear polarization detector designed based on the Marius extinction law. Experiments demonstrate that the detection methods and data processing have enhanced the signal-to-noise ratio as well as the accuracy of the system. It is shown that the brightness consistency of paired openings for the integrating sphere is better than 99.5%, the surface uniformity is better than 99~, and the de- gree of polarization is below 1%, which satisfies the needs of radiometric calibration of the multi-angle polarizing radiometer.