Potential Incoming Solar Radiation

Description

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!

References

Böhner, J., Antonić, O. (2009): Land Surface Parameters Specific to Topo-Climatology. In: Hengl, T. & Reuter, H.I. [Eds.]: Geomorphometry - Concepts, Software, Applications.

Hofierka, J., Šúri, M. (2002): The solar radiation model for Open source GIS: implementation and applications. International GRASS users conference in Trento, Italy, September 2002. ResearchGate

Oke, T.R. (1988): Boundary Layer Climates. London, Taylor & Francis.

Wilson, J.P., Gallant, J.C. (2000): Secondary topographic attributes. In: Wilson, J.P., Gallant, J.C. [Eds.]: Terrain analysis: Principles and applications. New York, John Wiley & Sons, Inc., 87-131. ResearchGate

Parameters

Command Line

Usage: saga_cmd ta_lighting 2 [-GRD_DEM ] [-GRD_SVF ] [-GRD_VAPOUR ] [-GRD_VAPOUR_DEFAULT ] [-GRD_LINKE ] [-GRD_LINKE_DEFAULT ] [-GRD_DIRECT ] [-GRD_DIFFUS ] [-GRD_TOTAL ] [-GRD_RATIO ] [-GRD_FLAT ] [-GRD_DURATION ] [-GRD_SUNRISE ] [-GRD_SUNSET ] [-SOLARCONST ] [-LOCALSVF ] [-UNITS ] [-SHADOW ] [-LOCATION ] [-LATITUDE ] [-PERIOD ] [-DAY ] [-DAY_STOP ] [-DAYS_STEP ] [-MOMENT ] [-HOUR_RANGE_MIN ] [-HOUR_RANGE_MAX ] [-HOUR_STEP ] [-METHOD ] [-ATMOSPHERE ] [-PRESSURE ] [-WATER ] [-DUST ] [-LUMPED ]
  -GRD_DEM:                 Elevation
	grid, input
  -GRD_SVF:                 Sky View Factor
	grid, input, optional
  -GRD_VAPOUR:              Water Vapour Pressure [mbar]
	grid, input, optional
  -GRD_VAPOUR_DEFAULT:   Default
	floating point number
	Minimum: 0.000000
	Default: 10.000000
  -GRD_LINKE:               Linke Turbidity Coefficient
	grid, input, optional
  -GRD_LINKE_DEFAULT:    Default
	floating point number
	Minimum: 0.000000
	Default: 3.000000
  -GRD_DIRECT:              Direct Insolation
	grid, output
  -GRD_DIFFUS:              Diffuse Insolation
	grid, output
  -GRD_TOTAL:               Total Insolation
	grid, output, optional
  -GRD_RATIO:               Direct to Diffuse Ratio
	grid, output, optional
  -GRD_FLAT:                Compare to Flat Terrain
	grid, output, optional
  -GRD_DURATION:            Duration of Insolation
	grid, output, optional
  -GRD_SUNRISE:             Sunrise
	grid, output, optional
  -GRD_SUNSET:              Sunset
	grid, output, optional
  -SOLARCONST:           Solar Constant [W/m²]
	floating point number
	Minimum: 0.000000
	Default: 1361.000000
  -LOCALSVF:                Local Sky View Factor
	boolean
	Default: 1
  -UNITS:                   Units
	choice
	Available Choices:
	[0] kWh/m²
	[1] kJ/m²
	[2] J/cm²
	Default: 0
  -SHADOW:                  Shadow
	choice
	Available Choices:
	[0] slim
	[1] fat
	[2] none
	Default: 1
  -LOCATION:
                                 Location
                                 	choice
                                 	Available Choices:
                                 	[0] constant latitude
                                 	[1] calculate from grid system
                                 	Default: 0
  -LATITUDE:             Latitude
	degree
	Minimum: -90.000000
	Maximum: 90.000000
	Default: 53.000000
  -PERIOD:
                                 Time Period
                                 	choice
                                 	Available Choices:
                                 	[0] moment
                                 	[1] day
                                 	[2] range of days
                                 	Default: 1
  -DAY:                    Day
	date
	Default: 2026-06-03
  -DAY_STOP:               Last Day
	date
	Default: 2026-06-03
  -DAYS_STEP:               Resolution [d]
	integer number
	Minimum: 1
	Default: 5
  -MOMENT:
                                 Moment [h]
                                 	floating point number
                                 	Minimum: 0.000000
                                 	Maximum: 24.000000
                                 	Default: 12.000000
  -HOUR_RANGE_MIN:       Time Span [h]
	value range
  -HOUR_RANGE_MAX:       Time Span [h]
	value range
  -HOUR_STEP:
                                 Resolution [h]
                                 	floating point number
                                 	Minimum: 0.000000
                                 	Maximum: 24.000000
                                 	Default: 0.500000
  -METHOD:
                                 Atmospheric Effects
                                 	choice
                                 	Available Choices:
                                 	[0] Height of Atmosphere and Vapour Pressure
                                 	[1] Air Pressure, Water and Dust Content
                                 	[2] Lumped Atmospheric Transmittance
                                 	[3] Hofierka and Šúri
                                 	Default: 2
  -ATMOSPHERE:
                                 Height of Atmosphere [m]
                                 	floating point number
                                 	Minimum: 0.000000
                                 	Default: 12000.000000
  -PRESSURE:
                                 Barometric Pressure [mbar]
                                 	floating point number
                                 	Minimum: 0.000000
                                 	Default: 1013.000000
  -WATER:                Water Content [cm]
	floating point number
	Minimum: 0.000000
	Default: 1.680000
  -DUST:                 Dust [ppm]
	floating point number
	Minimum: 0.000000
	Default: 100.000000
  -LUMPED:
                                 Lumped Atmospheric Transmittance [Percent]
                                 	floating point number
                                 	Minimum: 0.000000
                                 	Maximum: 100.000000
                                 	Default: 70.000000