The Australian Bureau of Meteorology has produced, in near real-time for more than three years, high resolution daily surface global solar exposure estimates over the Australian continent. Physical modelling of radiative transfer within the atmosphere has been used to provide these estimates from full resolution hourly visible Geostationary Meteorological Satellite (GMS) Stretched-Visible and Infrared Spin Scan Radiometer (S-VISSR) data. This paper describes the models and their calibration for estimating exposure from satellite observations. The accuracy of the exposure data is presented, along with the first high resolution initial climatology of exposure across Australia. The models provide high quality data. They perform best in clear and near clear-sky conditions, with the average deviation of model areal means from surface-based point pyranometer measurements being less than five per cent. In cloudy conditions, the average percentage deviation is larger, but absolute deviations remain small as the exposure is lower. Over most of the continent, the cloud conditions that actually occur lead to estimates being within eight per cent (mean modulus of daily percentage difference) of collocated point pyranometer measurements, an accuracy similar to or exceeding that of the older pyranometers which still comprised half of the Australian pyranometer network during this study.
Weymouth et al. (Wed,) studied this question.