Petkov Boyan, Vitale Vito, Tomasi Claudio, Bonafé Ubaldo, Scaglione Salvatore, Flori Daniele, Santaguida Riccardo, Gausa Michael, Hansen Georg, Colombo Tiziano
Institute of Atmospheric Sciences and Climate, Italian National Research Council, Bologna, Italy.
Appl Opt. 2006 Jun 20;45(18):4383-95. doi: 10.1364/ao.45.004383.
The ultraviolet narrowband filter radiometer (UV-RAD) designed by the authors to take ground-based measurements of UV solar irradiance, total ozone, and biological dose rate is described, together with the main characteristics of the seven blocked filters mounted on it, all of which have full widths at half maxima that range 0.67 to 0.98 nm. We have analyzed the causes of cosine response and calibration errors carefully to define the corresponding correction terms, paying particular attention to those that are due to the spectral displacements of the filter transmittance peaks from the integer wavelength values. The influence of the ozone profile on the retrieved ozone at large solar zenith angles has also been examined by means of field measurements. The opportunity of carrying out nearly monochromatic irradiance measurements offered by the UV-RAD allowed us to improve the procedure usually followed to reconstruct the solar spectrum at the surface by fitting the computed results, using radiative transfer models with field measurements of irradiance. Two long-term comparison campaigns took place, showing that a mean discrepancy of +0.3% exists between the UV-RAD total ozone values and those given by the Brewer #63 spectroradiometer and that mean differences of +0.3% and -0.9% exist between the erythemal dose rates determined with the UV-RAD and those obtained with the Brewer #63 and the Brewer #104 spectroradiometers, respectively.
介绍了作者设计的用于地面测量紫外太阳辐照度、总臭氧和生物剂量率的紫外窄带滤光片辐射计（UV-RAD），以及安装在其上的七个阻挡滤光片的主要特性，所有这些滤光片的半高全宽范围为0.67至0.98纳米。我们仔细分析了余弦响应和校准误差的原因，以确定相应的校正项，特别关注那些由于滤光片透过率峰值相对于整数波长值的光谱位移而产生的误差。还通过实地测量研究了臭氧廓线在大太阳天顶角下对反演臭氧的影响。UV-RAD提供了进行近单色辐照度测量的机会，这使我们能够改进通常采用的通过将计算结果与使用辐照度实地测量的辐射传输模型进行拟合来重建地表太阳光谱的程序。进行了两次长期对比活动，结果表明，UV-RAD的总臭氧值与布鲁尔#63光谱辐射计给出的值之间存在+0.3%的平均差异，并且用UV-RAD测定的红斑剂量率与分别用布鲁尔#63和布鲁尔#104光谱辐射计获得的红斑剂量率之间存在+0.3%和-0.9%的平均差异。
