视场角(field of view, FOV)是太阳辐射计的基础参数,也是太阳辐射计传递定标方法和室内积分球光源对比定标方法的关键参数,获取高精度的FOV是提高 此类定标方法精度的重要手段。基于矩阵扫描测量方法,针对CE318型太阳辐射计,研制了激光光源测量FOV系统,并将测量结果与传递定标法进行 了对比验证。结果表明:基于激光光源的矩阵扫描测量效果最好,不确定度为0.4%～1.1%;而基于太阳光源矩阵扫描测量受太阳运动的影响,因 此有一定的发散角,导致测量结果比激光光源测量结果小约1.3%～1.4%。此外,在太阳辐射计历史定标系数较多时,激光光源测量结果与传递定 标法计算的FOV结果一致性较好,说明传递定标法在历史数据多时也可以得到较精确的FOV结果。

Field of view (FOV) is the basic parameter of sun-photometer and also the key parameter for transfer calibration and inter-comparison of sun-photometers using an integrating sphere as light source in the laboratory. Obtaining high-precision FOV is important to improve the accuracy of sun-photometer calibration. Based on the matrix measurement method, a system using laser as a light source to measure the FOV of CE318 sun-photometer is developed, and then the FOV results of matrix method are compared with the transfer calibration method. The results indicate that the matrix measurement with laser has a FOV uncertainty of 0.4%～1.1%. Because of the movement during measurement process and divergence angle of sun, the FOV uncertainty based on matrix measurement with sun is about 1.3%～1.4% which is larger than the laser result. In addition, the more historical calibration records, the more accurate FOV can be obtained by using transfer calibration method by comparing with matrix approach with laser, which suggests that the transfer calibration method can obtain accurate FOV when historical records are enough.