The potential daily solar irradiation
Value of the potential daily solar radiation is basic input for deriving other meteorological parameters. It is calculated by bbo.solar_day module.
Inputs to the module are raster layer of altitude (dem), raster layer of slope in degrees (slope) and raster layer of aspect (aspect). Furthermore it is necessary to enter latitude (latitude) and longitude (longitude) in degrees for region where is going to be calculated solar radiation, number of first day (day from) and number of last day (day to) of calculation, step of calculation (calculation step) in hours.
Optionally, you can set the attribute for clean of mapset before calculation started (clean mapset). Module will erase raster of potential solar radiation for each day of the year if the attribute is set.
Output files are saved under the name psr_d< xxx >, where xxx is three-digit number of day. All output and auxiliary layers are saved in solar mapset, which is automatically set by the module.
Firstly the module create auxiliary raster layers, with latitude (tmp_latitude) and longitude (tmp_longitude) attribute for every cell. Than for every day is calculated raster of potential solar radiation with set step.The calculation is very time consuming, it may take several hours. The length of the calculation depends on the size of the input raster and calculation step.