On the reliability of HELIOSAT method: A comparison with experimental data

This study deals with comparison of Cameroonian ground based measurements with estimations done using satellite images, by applying the second version of the HELIOSAT method, as computed by the web tool HELIOCLIM of the SoDa project. Measurements and satellite resources were chosen for the same period of the year 1985, on ten Cameroonian locations, distributed with mean spatial resolution of 200 km between two neighbouring stations. Correlations curves are constructed between daily irradiation estimates from satellite data and from measurements. The consequent regression equations are established, using the least square method. Finally, a brief discussion is carried out on the spatial distribution of errors observed on results. Similarly to previous studies this study confirmed the capability of the method to produce good results for the Garoua location, and established its extension on other sahelian sites, comparatively to the poor agreement observed on southern sites. Furthermore, even if the study was not done on a long period, it brought out the necessity to correct the HELIOSAT results for many Cameroonian locations, to march the experimental results. (C) 2010 Elsevier Ltd. All rights reserved.