分光总日射表校准因子的迭代计算法

详细讨论了分光总日射表的校准方法。论证了以一台直接日射表和一台遮蔽的总日射表为标准的校准方法优于仅用一台直接日射表为标准的校准方法，并提出了分光总日射表校准因子的迭代计算法。该方法可以解决由于遮蔽的总日射表校准因子不准确而产生的误差。最后还讨论了在校准过程中时间准确的重要性，指出至少应准确到分，否则每分的误差通过太阳高度角的正弦会给直接日射值带来０．２％的系统误差。

AN ITERATION METHOD FOR DETERMINING THE CALIBRATION FACTOR OF SPECTRAL PYRANOMETER

In this article, the calibration method of spectral pyranometers is discussed in detail. It is demonstrated that the calibration method using a standard pyrheliometer and a shaded pyranometer is better than using only one standard pyrheliometer; and the iteration method for determining the calibration factor of spectral pyranometer is presented. This method may avoid the error caused by inaccuracy in the calibration factor of the shaded pyranometer. Finally, the importance of punctuality during calibration is demonstrated; it is shown that an accuracy to one minute is required, otherwise a 0.2% systematic error could appear in all direct insolation values through sink (h: solar altitude).