Spectral Scanning Measurement of High-Precision Solar Irradiance-Meter
LIU En-chao, LI Xin, ZHANG Yan-na, LI Wen-wei, ZHENG Xiao-bing
Key Laboratory of Optical Calibration and Characterization, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China
Abstract：In order to measure the radiation of the sun absolutely and retrieve the characterization of the atmosphere precisely, a high-precision solar spectral irradiance meter working in 0.4～1.0 μm band was developed. A Fèry prism was employed to disperse the incident sunlight and a closed-loop control method was adopted for spectral scanning in this solar irradiance meter. The design of spectral scanning measurement was depicted in detail. The design requirements of Fèry prism were given and spectral dispersion was achieved by single element. The trap detectors were used to ensure precise spectral measurement. According to the parameters of the trap detectors, the demands and method of temperature control were introduced. The design of spectral scanning structure was introduced, and wavelengths were positioned accurately. The requirements for parameters, stability and power supply of voice coil actuator were given and the wavelength position error of 0.025% was achieved. Spectral scanning measurement of 0.4～1.0 μm was accomplished in outdoor experiments. A comparison was carried out with visible-short wave infrared spectrometer and auto-sunphotometer(CE318). Results indicate that absorption peak locations of spectral scanning measurement of irradiance meter are correct, and the relative deviation from CE318 measurements is less than 0.13% for all day, and the relative deviation of optical depth in visible and near infrared band is less than 2% and 5%, respectively.
