“…In addition, there are operational and installation errors from miscalibration, a lack of regular cleaning of dust, snow, water droplets and bird droppings, and shadows cast on the equipment by nearby trees and buildings [12]. These factors cause systematic and random errors in the data, which have been reported in the literature [13][14][15][16][17]. Therefore, sensors that are measuring SR are unlike other meteorological instruments in that they need high maintenance to sustain performance and collection of high quality data, and their data recording needs to be checked regularly before using in scientific studies [1,11,18].…”