Module Potential Incoming Solar Radiation

Calculation of potential incoming solar radiation (insolation).
Times of sunrise/sunset will only be calculated if time span is set to single day.

References:

Boehner, J., Antonic, O. (2009): Land Surface Parameters Specific to Topo-Climatology. in Hengl, T. & Reuter, H.I. [Eds.]: Geomorphometry - Concepts, Software, Applications.
Oke, T.R. (1988): Boundary Layer Climates. London, Taylor & Francis.
Wilson, J.P., Gallant, J.C. [Eds.] (2000): Terrain Analysis - Principles and Applications. New York, John Wiley & Sons, Inc.
Joint Research Centre: GIS solar radiation database for Europe and Solar radiation and GIS.
Hofierka, J., Suri, M. (2002): The solar radiation model for Open source GIS: implementation and applications. International GRASS users conference in Trento, Italy, September 2002. pdf.

*) Most options should do well, but TAPES-G based diffuse irradiance calculation ('Atmospheric Effects' methods 2 and 3) needs further revision!

Author: O.Conrad (c) 2010
Specification: grid
Menu: Terrain Analysis|Lighting

Parameters

	Name	Type	Identifier	Description	Constraints
Input	Elevation	Grid (input)	`GRD_DEM`	-	-
	Sky View Factor (*)	Grid (optional input)	`GRD_SVF`	-	-
	Water Vapour Pressure [mbar] (*)	Grid (optional input)	`GRD_VAPOUR`	-	-
	Linke Turbidity Coefficient (*)	Grid (optional input)	`GRD_LINKE`	-	-
Output	Direct Insolation	Grid (output)	`GRD_DIRECT`	-	-
	Diffuse Insolation	Grid (output)	`GRD_DIFFUS`	-	-
	Total Insolation (*)	Grid (optional output)	`GRD_TOTAL`	-	-
	Direct to Diffuse Ratio (*)	Grid (optional output)	`GRD_RATIO`	-	-
	Duration of Insolation (*)	Grid (optional output)	`GRD_DURATION`	-	-
	Sunrise (*)	Grid (optional output)	`GRD_SUNRISE`	-	-
	Sunset (*)	Grid (optional output)	`GRD_SUNSET`	-	-
Options	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: 1
	Update	Choice	`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	`UPDATE_STRETCH`	-	Minimum: 0.000000 Default: 1.000000
	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
	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.	-
	Time Resolution [h]: Day	Floating point	`HOUR_STEP`	Time step size for a day's calculation given in hours.	Minimum: 0.000000 Maximum: 24.000000 Default: 0.500000
	Time Resolution [d]: Range of Days	Integer	`DAYS_STEP`	Time step size for a range of days calculation given in days.	Minimum: 1 Default: 5
	Day	Integer	`DAY_A`	-	Minimum: 1 Maximum: 31 Default: 16
	Month	Choice	`MON_A`	-	Available Choices: [0] January [1] February [2] March [3] April [4] May [5] June [6] July [7] August [8] September [9] October [10] November [11] December Default: 9
	Year	Integer	`YEAR_A`	-	Default: 2015
	Day	Integer	`DAY_B`	-	Minimum: 1 Maximum: 31 Default: 16
	Month	Choice	`MON_B`	-	Available Choices: [0] January [1] February [2] March [3] April [4] May [5] June [6] July [7] August [8] September [9] October [10] November [11] December Default: 9
	Year	Integer	`YEAR_B`	-	Default: 2015
	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
(*) optional

Command-line

Usage: saga_cmd ta_lighting 2 [-GRD_DEM <str>] [-GRD_SVF <str>] [-GRD_VAPOUR <str>] [-GRD_VAPOUR_DEFAULT <str>] [-GRD_LINKE <str>] [-GRD_LINKE_DEFAULT <str>] [-GRD_DIRECT <str>] [-GRD_DIFFUS <str>] [-GRD_TOTAL <str>] [-GRD_RATIO <str>] [-GRD_DURATION <str>] [-GRD_SUNRISE <str>] [-GRD_SUNSET <str>] [-SOLARCONST <str>] [-LOCALSVF <str>] [-UNITS <str>] [-SHADOW <str>] [-UPDATE <str>] [-UPDATE_STRETCH <str>] [-LOCATION <str>] [-LATITUDE <str>] [-PERIOD <str>] [-MOMENT <str>] [-HOUR_RANGE_MIN <str>] [-HOUR_RANGE_MAX <str>] [-HOUR_STEP <str>] [-DAYS_STEP <num>] [-DAY_A <num>] [-MON_A <str>] [-YEAR_A <num>] [-DAY_B <num>] [-MON_B <str>] [-YEAR_B <num>] [-METHOD <str>] [-ATMOSPHERE <str>] [-PRESSURE <str>] [-WATER <str>] [-DUST <str>] [-LUMPED <str>]
  -GRD_DEM:<str>           	Elevation
	Grid (input)
  -GRD_SVF:<str>           	Sky View Factor
	Grid (optional input)
  -GRD_VAPOUR:<str>        	Water Vapour Pressure [mbar]
	Grid (optional input)
  -GRD_VAPOUR_DEFAULT:<str>	Default
	Floating point
	Minimum: 0.000000
	Default: 10.000000
  -GRD_LINKE:<str>         	Linke Turbidity Coefficient
	Grid (optional input)
  -GRD_LINKE_DEFAULT:<str> 	Default
	Floating point
	Minimum: 0.000000
	Default: 3.000000
  -GRD_DIRECT:<str>        	Direct Insolation
	Grid (output)
  -GRD_DIFFUS:<str>        	Diffuse Insolation
	Grid (output)
  -GRD_TOTAL:<str>         	Total Insolation
	Grid (optional output)
  -GRD_RATIO:<str>         	Direct to Diffuse Ratio
	Grid (optional output)
  -GRD_DURATION:<str>      	Duration of Insolation
	Grid (optional output)
  -GRD_SUNRISE:<str>       	Sunrise
	Grid (optional output)
  -GRD_SUNSET:<str>        	Sunset
	Grid (optional output)
  -SOLARCONST:<str>        	Solar Constant [W / m?]
	Floating point
	Minimum: 0.000000
	Default: 1367.000000
  -LOCALSVF:<str>          	Local Sky View Factor
	Boolean
	Default: 1
  -UNITS:<str>             	Units
	Choice
	Available Choices:
	[0] kWh / m2
	[1] kJ / m2
	[2] J / cm2
	Default: 0
  -SHADOW:<str>            	Shadow
	Choice
	Available Choices:
	[0] slim
	[1] fat
	[2] none
	Default: 1
  -UPDATE:<str>            	Update
	Choice
	Available Choices:
	[0] do not update
	[1] fit histogram stretch for each time step
	[2] constant histogram stretch for all time steps
	Default: 0
  -UPDATE_STRETCH:<str>    	Constant Histogram Stretch
	Floating point
	Minimum: 0.000000
	Default: 1.000000
  -LOCATION:<str>          	Location
	Choice
	Available Choices:
	[0] constant latitude
	[1] calculate from grid system
	Default: 0
  -LATITUDE:<str>          	Latitude
	Degree
	Minimum: -90.000000
	Maximum: 90.000000
	Default: 53.000000
  -PERIOD:<str>            	Time Period
	Choice
	Available Choices:
	[0] moment
	[1] day
	[2] range of days
	Default: 1
  -MOMENT:<str>            	Moment [h]
	Floating point
	Minimum: 0.000000
	Maximum: 24.000000
	Default: 12.000000
  -HOUR_RANGE_MIN:<str>    	Time Span [h]
	Value range
  -HOUR_RANGE_MAX:<str>    	Time Span [h]
	Value range
  -HOUR_STEP:<str>         	Time Resolution [h]: Day
	Floating point
	Minimum: 0.000000
	Maximum: 24.000000
	Default: 0.500000
  -DAYS_STEP:<num>         	Time Resolution [d]: Range of Days
	Integer
	Minimum: 1
	Default: 5
  -DAY_A:<num>             	Day
	Integer
	Minimum: 1
	Maximum: 31
	Default: 16
  -MON_A:<str>             	Month
	Choice
	Available Choices:
	[0] January
	[1] February
	[2] March
	[3] April
	[4] May
	[5] June
	[6] July
	[7] August
	[8] September
	[9] October
	[10] November
	[11] December
	Default: 9
  -YEAR_A:<num>            	Year
	Integer
	Default: 2015
  -DAY_B:<num>             	Day
	Integer
	Minimum: 1
	Maximum: 31
	Default: 16
  -MON_B:<str>             	Month
	Choice
	Available Choices:
	[0] January
	[1] February
	[2] March
	[3] April
	[4] May
	[5] June
	[6] July
	[7] August
	[8] September
	[9] October
	[10] November
	[11] December
	Default: 9
  -YEAR_B:<num>            	Year
	Integer
	Default: 2015
  -METHOD:<str>            	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 Suri
	Default: 2
  -ATMOSPHERE:<str>        	Height of Atmosphere [m]
	Floating point
	Minimum: 0.000000
	Default: 12000.000000
  -PRESSURE:<str>          	Barometric Pressure [mbar]
	Floating point
	Minimum: 0.000000
	Default: 1013.000000
  -WATER:<str>             	Water Content [cm]
	Floating point
	Minimum: 0.000000
	Default: 1.680000
  -DUST:<str>              	Dust [ppm]
	Floating point
	Minimum: 0.000000
	Default: 100.000000
  -LUMPED:<str>            	Lumped Atmospheric Transmittance [Percent]
	Floating point
	Minimum: 0.000000
	Maximum: 100.000000
	Default: 70.000000