Calibration of selected pyranometers and satellite derived solar radiation in Puerto Rico

Knowledge of solar radiation at the ground surface is valuable for many disciplines. In this study, ground–based sensors at Fortuna and Mayaguez, Puerto Rico, were used to calibrate daily–integrated satellite–derived solar radiation. The calibration equations yielded R² values of 0.88 and 0.83 at Fortuna and Mayaguez, respectively. A regression equation was also derived based on the combined data from the two locations with an R² of 0.87. The calibration equations for Fortuna and UPRM were validated using 283 and 227 days of solar radiation data from 2010, respectively. The combined data equation (intended as an island–wide equation) worked well at UPRM but not at Fortuna. We recommend, for locations other than the study areas, that the uncorrected remotely sensed data be used. At the study sites, the uncorrected data produced reasonably accurate results with a maximum 6.22% error between the mean estimated and measured solar radiation.

Keywords: solar radiation, pyranometers, remote sensing, GOES, Puerto Rico, Caribbean, calibration, satellites