【摘要】 光谱型太阳辐射计可以直接测量得到太阳辐射变化，反映各个波段对应的辐射度信息，其直射通道全波段的仪器定标精度直接影响大气参数的反演精度。常用的Langley拟合法在大气强吸收波段定标精度不高，最终计算的可降水量、强吸收波段透过率数据均存在一定的误差。为了满足可见-近红外全波段太阳光谱的高精度测量需求，提出一种非吸收波段的Langley定标法和基于理论计算强吸收波段大气层顶太阳辐照度相结合的混合定标法，得到光谱辐射计全波段的定标值。因为仪器响应函数是随波长缓慢变化的，通过非吸收波段定标的仪器响应函数按波长线性插值得到强吸收波段下的仪器响应函数，再结合大气层顶太阳辐照度和仪器定标值之间的关系得到强吸收波段下的仪器定标值。通过对比Langley定标法、改进Langley法以及混合定标法的仪器定标值变化曲线发现，前两种方法在强吸收波段的定标值有明显的突变，而混合定标法计算的强吸收波段仪器定标值变化更平缓，符合仪器响应规律；通过对比不同定标法测量的大气透过率与CART理论计算透过率的相对偏差，发现混合定标法平均偏差减少了1.15%,误差的减小主要归因于混合定标法提高了强吸收波段大气透过率的测量精度。将改进Langley法和混合定标法计算得到的可降水量数据与国外同类型的POM辐射计测量得到的可降水量数据进行对比，混合定标法计算得到的可降水量与POM辐射计的计算结果几乎一致，相对误差在10%以下，而相对于改进Langley定标法平均减少了40%;对于测量的大气透过率，与POM辐射计测量的透过率数据进行对比，在940 nm水汽强吸收带处，混合定标法测量的相对误差减小了25%。因此混合定标法对于光谱型太阳辐射计直射通道全波段定标、可降水量计算以及强吸收波段透过率计算有应用价值，较好地改善了强吸收波段的定标精度。更多还原

【Abstract】 Spectral solar radiometers can directly measure the variation of solar radiation and reflect the radiation information corresponding to each band. The calibration accuracy of the instrument in the whole band of the direct ray channel directly affects the inversion accuracy of atmospheric parameters. The commonly used Langley fitting method has low calibration accuracy in the atmospheric strong absorption band, and there are certain errors in the final calculation of precipitable water and strong absorption band transmittance data. In order to meet the requirements of high-precision measurement of the visible-near-infrared full-band solar spectrum, this paper proposes a Mixing calibration method combining the Langley calibration method of the non-absorption band and the Mixing calibration method based on theoretical calculation of solar irradiance at the top of the atmosphere of the strong absorption band. It obtains the calibration value of the full band of the spectral radiometer. Because the instrumental response function changes slowly with wavelength, the instrumental response function in the strong absorption band is obtained by linear interpolation of the calibration instrument response function in the non-absorption band according to wavelength. Then the instrumental response function in the strong absorption band is obtained by combining the relationship between the solar irradiance at the top of the atmosphere and the instrumental calibration value. By comparing the change curves of instrument calibration values of the Langley calibration method, improved Langley calibration method and Mixing calibration method, it is found that the calibration values of the former two methods have obvious mutations in the strong absorption band, while the calibration values of the Mixing calibration method change more gradually in the strong absorption band, which conforms to the law of instrument response. By comparing the relative deviation between the atmospheric transmittance measured by different calibration methods and the transmittance calculated by CART theory, it is found that the average deviation of the Mixing calibration method is reduced by 1.15%, which is mainly attributed to the improvement of the measurement accuracy of atmospheric transmittance in the strong absorption band by the Mixing calibration method. The precipitation data calculated by the improved Langley method and the Mixing calibration method are compared with those measured by the same type of POM radiometer abroad. The results calculated by the Mixing calibration method are almost consistent with those calculated by the POM radiometer, and the relative error is less than 10%. Compared with the improved Langley scaling method, it reduced by 40% on average. For the atmospheric transmittance measured, compared with the POM radiometer transmittance data, the relative error of the Mixing calibration measurement is reduced by 25% at the 940 nm vapor absorption zone. Therefore, the Mixing calibration method is of great application value to the full-band calibration of a direct channel of spectral solar radiometer, the calculation of precipitable water and the calculation of transmittance of the strong absorption band, and improves the calibration accuracy of the strong absorption band.更多还原