Location: Hydrology and Remote Sensing Laboratory
2012 Annual Report
A new model framework including these improvements has been constructed and is easily portable to any McIDAS (Man computer Interactive Data System) location. USCRN (U.S. Climate Reference Network) pyranometer data access has been automated in order to validate satellite daily and hourly insolation estimates from the new insolation model and calibrate the visible channel on GOES satellites via newly-developed techniques. Model resolution has been improved to 10-km spatial (down from 20 km), and half-hour temporal (up from hourly) to facilitate higher resolution mapping applications. Finally, it is apparent that errors in hourly satellite estimates of insolation can often be related to the bidirectional components of radiation that the insolation model does not take into account. We are researching simple bidirectional models that might be used to improve the accuracy of the hourly satellite estimates. Methods researched to date either require pre-classification of the scene type (clear, partly cloudy, ocean, land, etc.), which would make the estimation of insolation from GOES an iterative and computationally-expensive effort, or simply too much computer time due to the complexity of the radiative transfer model.
The new insolation model has been transferred to Space Science and Engineering Center (SSEC) Data Center at the University of Wisconsin, where it underwent debugging and testing. This model was transferred to operations. Both the old model and the new model are running simultaneously to allow further comparisons between the two versions. Although the new model tends to have large errors under the same conditions as the old version, the overall mean error is smaller due to the improved calibration.