Module Potential Incoming Solar Radiation

Calculation of potential incoming solar radiation (insolation).

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.

*) 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`	-	-
	Latitude [degree] (*)	Grid (optional input)	`GRD_LAT`	-	-
	Longitude [degree] (*)	Grid (optional input)	`GRD_LON`	-	-
Output	Direct Insolation	Grid (output)	`GRD_DIRECT`	-	-
	Diffuse Insolation	Grid (output)	`GRD_DIFFUS`	-	-
	Total Insolation (*)	Grid (optional output)	`GRD_TOTAL`	Total insolation, the sum of direct and diffuse incoming solar radiation.	-
	Direct to Diffuse Ratio (*)	Grid (optional output)	`GRD_RATIO`	-	-
	Duration of Insolation (*)	Grid (optional output)	`DURATION`	-	-
	Sunrise (*)	Grid (optional output)	`SUNRISE`	time of sunrise/sunset is only calculated if time span is set to single day	-
	Sunset (*)	Grid (optional output)	`SUNSET`	time of sunrise/sunset is only calculated if time span is set to single day	-
Options	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. The first is slightly faster but might show some artifacts.	Available Choices: [0] slim [1] fat Default: 1
	Latitude	Degree	`LATITUDE`	-	Minimum: -90.000000 Maximum: 90.000000 Default: 53.000000
	Planetary Bending	Parameters	`BENDING`	-	6 Parameters: - 1. Default: 0 - 2. Minimum: 0.000000 Default: 6366737.960000 - 3. Available Choices: [0] bottom [1] center [2] top [3] user defined reference Default: 3 - 4. Default: 0.000000 - 5. Available Choices: [0] left [1] center [2] right [3] user defined reference Default: 1 - 6. Default: 0.000000
	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	`DHOUR`	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	`DDAYS`	Time step size for a range of days calculation given in days.	Minimum: 1 Default: 5
	Update	Choice	`UPDATE`	show direct insolation for each time step.	Available Choices: [0] do not update [1] update, colour stretch for each time step [2] update, fixed colour stretch Default: 0
	Day of Month	Choice	`DAY_A`	-	Available Choices: [0] 1 [1] 2 [2] 3 [3] 4 [4] 5 [5] 6 [6] 7 [7] 8 [8] 9 [9] 10 [10] 11 [11] 12 [12] 13 [13] 14 [14] 15 [15] 16 [16] 17 [17] 18 [18] 19 [19] 20 [20] 21 [21] 22 [22] 23 [23] 24 [24] 25 [25] 26 [26] 27 [27] 28 [28] 29 [29] 30 [30] 31 Default: 20
	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: 2
	Day of Month	Choice	`DAY_B`	-	Available Choices: [0] 1 [1] 2 [2] 3 [3] 4 [4] 5 [5] 6 [6] 7 [7] 8 [8] 9 [9] 10 [10] 11 [11] 12 [12] 13 [13] 14 [14] 15 [15] 16 [16] 17 [17] 18 [18] 19 [19] 20 [20] 21 [21] 22 [22] 23 [23] 24 [24] 25 [25] 26 [26] 27 [27] 28 [28] 29 [29] 30 [30] 31 Default: 20
	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: 3
	Atmospheric Effects	Choice	`METHOD`	-	Available Choices: [0] Height of Atmosphere and Vapour Pressure [1] Air Pressure, Water and Dust Content [2] Lumped Atmospheric Transmittance Default: 0
	Height of Atmosphere [m]	Floating point	`ATMOSPHERE`	-	Minimum: 0.000000 Default: 12000.000000
	Water Vapour Pressure [mbar]	Floating point	`VAPOUR`	This value is used as constant if no vapour pressure grid is given.	Minimum: 0.000000 Default: 10.000000
	Atmospheric 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_LAT <str>] [-GRD_LON <str>] [-GRD_DIRECT <str>] [-GRD_DIFFUS <str>] [-GRD_TOTAL <str>] [-GRD_RATIO <str>] [-DURATION <str>] [-SUNRISE <str>] [-SUNSET <str>] [-SOLARCONST <str>] [-LOCALSVF <str>] [-UNITS <str>] [-SHADOW <str>] [-LATITUDE <str>] [-BENDING_BENDING <str>] [-BENDING_RADIUS <str>] [-BENDING_LAT_OFFSET <str>] [-BENDING_LAT_REF_USER <str>] [-BENDING_LON_OFFSET <str>] [-BENDING_LON_REF_USER <str>] [-PERIOD <str>] [-MOMENT <str>] [-HOUR_RANGE_MIN <str>] [-HOUR_RANGE_MAX <str>] [-DHOUR <str>] [-DDAYS <num>] [-UPDATE <str>] [-DAY_A <str>] [-MON_A <str>] [-DAY_B <str>] [-MON_B <str>] [-METHOD <str>] [-ATMOSPHERE <str>] [-VAPOUR <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_LAT:<str>             	Latitude [degree]
	Grid (optional input)
  -GRD_LON:<str>             	Longitude [degree]
	Grid (optional input)
  -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)
  -DURATION:<str>            	Duration of Insolation
	Grid (optional output)
  -SUNRISE:<str>             	Sunrise
	Grid (optional output)
  -SUNSET:<str>              	Sunset
	Grid (optional output)
  -SOLARCONST:<str>          	Solar Constant [W / m2]
	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
	Default: 1
  -LATITUDE:<str>            	Latitude
	Degree
	Minimum: -90.000000
	Maximum: 90.000000
	Default: 53.000000
  -BENDING_BENDING:<str>     	Include Planetery Bending
	Boolean
	Default: 0
  -BENDING_RADIUS:<str>      	Planetary Radius
	Floating point
	Minimum: 0.000000
	Default: 6366737.960000
  -BENDING_LAT_OFFSET:<str>  	Latitude relates to grid's...
	Choice
	Available Choices:
	[0] bottom
	[1] center
	[2] top
	[3] user defined reference
	Default: 3
  -BENDING_LAT_REF_USER:<str>	Latitude (user defined reference)
	Floating point
	Default: 0.000000
  -BENDING_LON_OFFSET:<str>  	Local time relates to grid's...
	Choice
	Available Choices:
	[0] left
	[1] center
	[2] right
	[3] user defined reference
	Default: 1
  -BENDING_LON_REF_USER:<str>	Local Time (user defined reference)
	Floating point
	Default: 0.000000
  -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
  -DHOUR:<str>               	Time Resolution [h]: Day
	Floating point
	Minimum: 0.000000
	Maximum: 24.000000
	Default: 0.500000
  -DDAYS:<num>               	Time Resolution [d]: Range of Days
	Integer
	Minimum: 1
	Default: 5
  -UPDATE:<str>              	Update
	Choice
	Available Choices:
	[0] do not update
	[1] update, colour stretch for each time step
	[2] update, fixed colour stretch
	Default: 0
  -DAY_A:<str>               	Day of Month
	Choice
	Available Choices:
	[0] 1
	[1] 2
	[2] 3
	[3] 4
	[4] 5
	[5] 6
	[6] 7
	[7] 8
	[8] 9
	[9] 10
	[10] 11
	[11] 12
	[12] 13
	[13] 14
	[14] 15
	[15] 16
	[16] 17
	[17] 18
	[18] 19
	[19] 20
	[20] 21
	[21] 22
	[22] 23
	[23] 24
	[24] 25
	[25] 26
	[26] 27
	[27] 28
	[28] 29
	[29] 30
	[30] 31
	Default: 20
  -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: 2
  -DAY_B:<str>               	Day of Month
	Choice
	Available Choices:
	[0] 1
	[1] 2
	[2] 3
	[3] 4
	[4] 5
	[5] 6
	[6] 7
	[7] 8
	[8] 9
	[9] 10
	[10] 11
	[11] 12
	[12] 13
	[13] 14
	[14] 15
	[15] 16
	[16] 17
	[17] 18
	[18] 19
	[19] 20
	[20] 21
	[21] 22
	[22] 23
	[23] 24
	[24] 25
	[25] 26
	[26] 27
	[27] 28
	[28] 29
	[29] 30
	[30] 31
	Default: 20
  -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: 3
  -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
	Default: 0
  -ATMOSPHERE:<str>          	Height of Atmosphere [m]
	Floating point
	Minimum: 0.000000
	Default: 12000.000000
  -VAPOUR:<str>              	Water Vapour Pressure [mbar]
	Floating point
	Minimum: 0.000000
	Default: 10.000000
  -PRESSURE:<str>            	Atmospheric 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