Abstract: A two-step model based on MODIS remote sensing data and statistical inversion method for calculation of high resolution ground solar radiation is constructed. Firstly, monthly solar radiation percentage of grid points is calculated based on the correlation between remote sensing cloud cover and percentage of sunshine at ground level; secondly, the solar radiation of grid point is calculated based on the correlation between percentage of sunshine and solar radiation. Finally, this model is used to calculate the surface solar radiation with 1km grid resolution in Sichuan province, and the results are evaluated by actual total radiation from six representative radiation stations. The results show that the annual total radiation in Sichuan province ranges from 3102MJ·m⁻² to 6659MJ·m⁻². Among it, the lowest value occurs in the southeast of Sichuan Basin and the highest value occurs in the Western Sichuan Plateau. The calculated monthly solar radiation of the six representative stations are basically consistent with the observation results. Specifically, the absolute errors of calculated annual radiation are less than 100MJ·m−2 and the relative errors are less than 2%, which shows that the proposed model has high simulation accuracy and can be used to calculate the surface solar radiation in Sichuan province.

Key words: Solar radiation, MODIS data, Sichuan province