Development of a broadband spectroradiometer

Spectral measurements of the solar radiation at the Earth´s surface are important for meteorological, environmental, photovoltaic, and biomass study etc. Especially a long-term measurements and in-situ measurements are valid and efficient methods. Two types of spectroradiometers were developed for making those measurements in all weather conditions. One is a UV-VIS spectroradiometer for a wavelength of 350–1050 nm, and the other is a NIR for 900–1700 nm. The cosine errors of both instruments are less than ±5% over zenith angles ±80° and have no significant wavelength dependence. By absolute radiometric calibration, two instruments can measure the solar spectral radiation from 350 nm to 1700 nm with resolution less than 8 nm simultaneously. In this paper, the development concept, the outline of the instruments and their application to outdoor PV performance evaluation are described.