为了提高太阳辐射观测仪测量准确度, 针对余弦校正器自身漫射特性和菲涅耳反射引起的余弦误差, 研究了不同安装形式、不同结构下修正余弦误差的方法.结合太阳辐射特性和余弦误差的产生因素, 提出了余弦校正器外露、余弦器外露配合挡光环两种安装形式下的余弦误差修正方法, 以及余弦校正器、积分腔两种结构形式下的余弦误差修正方法.根据太阳辐射观测仪的使用要求, 利用 TracePro对不同安装方式下的余弦误差进行建模仿真, 利用高准直性太阳模拟器配合转台和转臂模拟不同方向的准直太阳光, 并实测余弦误差.实测结果表明, 余弦器外露配合挡光环形式下, 入射角小于±80°, 余弦误差可优于±6%.该修正方法可有效地减小太阳辐射光大入射角情况下的余弦误差, 提高太阳辐射观测准确度.

In order to improve measurement accuracy of solar radiation observation instrument, aiming at cosine error caused by characteristics of diffusion and Fresnel diffraction,a method of correcting cosine in case of different installation forms and different structures was researched. Considering the solar radiation characteristics and cosine corrector production factor, cosine error correction method was proposed in installation forms of cosine error exposed and cosine error exposed cooperating stop ring, while the method in two structures of cosine corrector and integral cavity was proposed. According to the requirements, cosine error was modulated and simulated by different installation methods by TracePro software. Using high collimation solar simulator, turntable and rotating arm, different directions sunlight were simulated, and the cosine error was measured. The results show that in the installation forms of cosine error exposed cooperating stop ring, the incident angle is less than ±80, the cosine error is better than 6%. The correction method can reduce cosine error effectively with the condition of large incident angle, and improve the accuracy of of solar radiation observation.