Calculation of potential incoming solar radiation (insolation). Times of sunrise/sunset will only be calculated if time span is set to single day.
Most options should do well, but TAPES-G based diffuse irradiance calculation ('Atmospheric Effects' methods 2 and 3) needs further revision!
|   | Name | Type | Identifier | Description | Constraints | 
| Input | Elevation | Grid, input | GRD_DEM | - | - | 
 | Sky View Factor (*) | Grid, input, optional | GRD_SVF | - | - | 
 | Water Vapour Pressure [mbar] (*) | Grid, input, optional | GRD_VAPOUR | - | - | 
 | Linke Turbidity Coefficient (*) | Grid, input, optional | GRD_LINKE | - | - | 
| Output | Direct Insolation | Grid, output | GRD_DIRECT | - | - | 
 | Diffuse Insolation | Grid, output | GRD_DIFFUS | - | - | 
 | Total Insolation (*) | Grid, output, optional | GRD_TOTAL | - | - | 
 | Direct to Diffuse Ratio (*) | Grid, output, optional | GRD_RATIO | - | - | 
 | Compare to Flat Terrain (*) | Grid, output, optional | GRD_FLAT | - | - | 
 | Duration of Insolation (*) | Grid, output, optional | GRD_DURATION | - | - | 
 | Sunrise (*) | Grid, output, optional | GRD_SUNRISE | - | - | 
 | Sunset (*) | Grid, output, optional | GRD_SUNSET | - | - | 
| Options | Grid System | Grid system | PARAMETERS_GRID_SYSTEM | - | - | 
 | Default | Floating point | GRD_VAPOUR_DEFAULT | default value if no grid has been selected | Minimum: 0.000000 Default: 10.000000 | 
 | Default | Floating point | GRD_LINKE_DEFAULT | default value if no grid has been selected | Minimum: 0.000000 Default: 3.000000 | 
 | Solar Constant [W / m²] | Floating point | SOLARCONST | - | Minimum: 0.000000 Default: 1367.000000 | 
 | Local Sky View Factor | Boolean | LOCALSVF | Use sky view factor based on local slope (after Oke 1988), if no sky viev factor grid is given. | Default: 1 | 
 | Units | Choice | UNITS | Units for output radiation values. | Available Choices: [0] kWh / m² [1] kJ / m² [2] J / cm² Default: 0 | 
 | Shadow | Choice | SHADOW | Choose 'slim' to trace grid node's shadow, 'fat' to trace the whole cell's shadow, or ignore shadowing effects. The first is slightly faster but might show some artifacts. | Available Choices: [0] slim [1] fat [2] none Default: 0 | 
 | Location | Choice | LOCATION | - | Available Choices: [0] constant latitude [1] calculate from grid system Default: 0 | 
 | Latitude | Degree | LATITUDE | - | Minimum: -90.000000 Maximum: 90.000000 Default: 53.000000 | 
 | Time Period | Choice | PERIOD | - | Available Choices: [0] moment [1] day [2] range of days Default: 1 | 
 | Day | Date | DAY | - | Default: 2020-10-09 | 
 | Last Day | Date | DAY_STOP | - | Default: 2020-10-09 | 
 | Resolution [d] | Integer | DAYS_STEP | Time step size for a range of days calculation given in days. | Minimum: 1 Default: 5 | 
 | Moment [h] | Floating point | MOMENT | - | Minimum: 0.000000 Maximum: 24.000000 Default: 12.000000 | 
 | Time Span [h] | Value range | HOUR_RANGE | Time span used for the calculation of daily radiation sums. | - | 
 | Resolution [h] | Floating point | HOUR_STEP | Time step size for a day's calculation given in hours. | Minimum: 0.000000 Maximum: 24.000000 Default: 0.500000 | 
 | Atmospheric Effects | Choice | METHOD | - | Available Choices: [0] Height of Atmosphere and Vapour Pressure [1] Air Pressure, Water and Dust Content [2] Lumped Atmospheric Transmittance [3] Hofierka and Suri Default: 2 | 
 | Height of Atmosphere [m] | Floating point | ATMOSPHERE | - | Minimum: 0.000000 Default: 12000.000000 | 
 | Barometric Pressure [mbar] | Floating point | PRESSURE | - | Minimum: 0.000000 Default: 1013.000000 | 
 | Water Content [cm] | Floating point | WATER | Water content of a vertical slice of atmosphere in cm: 1.5 to 1.7, average=1.68 | Minimum: 0.000000 Default: 1.680000 | 
 | Dust [ppm] | Floating point | DUST | Dust factor: 100 ppm (standard) | Minimum: 0.000000 Default: 100.000000 | 
 | Lumped Atmospheric Transmittance [Percent] | Floating point | LUMPED | The transmittance of the atmosphere, usually between 60 and 80 percent. | Minimum: 0.000000 Maximum: 100.000000 Default: 70.000000 | 
 | Update | Choice, GUI | UPDATE | show direct insolation for each time step. | Available Choices: [0] do not update [1] fit histogram stretch for each time step [2] constant histogram stretch for all time steps Default: 0 | 
 | Constant Histogram Stretch | Floating point, GUI | UPDATE_STRETCH | - | Minimum: 0.000000 Default: 1.000000 | 
| (*) optional |