3D Analyst Tools ArcToolbox

Points Solar Radiation Tool

How to use Points Solar Radiation Tool in Arc Toolbox??

Points Solar Radiation

Path to access the tool

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Points Solar Radiation Tool, Solar Radiation Toolset, Spatial Analyst Tools Toolbox

 

Points Solar Radiation

Derives incoming solar radiation for specific locations in a point feature class or location table.

1.    Input raster

Input elevation surface raster.

2.    Input points feature or table

The input point feature class or table specifying the locations to analyze solar radiation.

3.    Output global radiation features

The output feature class representing the global radiation or amount of incoming solar insolation (direct + diffuse) calculated for each location.

The output has units of watt hours per square meter (WH/m2).

4.    Height offset (optional)

The height (in meters) above the DEM surface for which calculations are to be performed.

The height offset will be applied to all input locations.

5.    Latitude (optional)

The latitude for the site area. The units are decimal degrees, with positive values for the northern hemisphere and negative for the southern.

For input surface rasters containing a spatial reference, the mean latitude is automatically calculated; otherwise, latitude will default to 45 degrees.

6.    Sky size / Resolution (optional)

The resolution or sky size for the viewshed, sky map, and sun map rasters. The units are cells.

The default creates a raster of 200 by 200 cells.

7.    Time configuration (optional)

Specifies the time period to use for the calculations.

1. Special days—Calculates solar insolation for the solstice days (summer and winter) and the equinox days (where the insolation for both spring and fall equinox are the same).
2. Within a day—Performs calculations for a specified time period within one single day.

Select the Julian Day and enter the start and end times. When the start time and the end time are the same, instantaneous insolation will be calculated. When the start time is before sunrise and the end time is after sunset, insolation will be calculated for the whole day.

• To facilitate entering the correct day, use the calendar button to open the Calendar dialog box.
• To set start and end times, use the clock button to open the Time Conversion dialog box. Here you can enter the local solar time, or the local standard time, while correcting for your degree of longitude and time zone.

Multiple days in a year—Performs calculations for a specific multiple-day period within a year.

• Specify the start year, start day, and end day. When the end day is smaller than the start day,the end day is considered to be in the following year. The default time configuration starts on day 5 and ends on day 160 of the current Julian year.

To facilitate entering the correct days, use the calendar button to open the Calendar dialog box.

• Whole year with monthly interval—Performs calculations for an entire year using monthly intervals for calculations.

If the Create outputs for each interval option is checked, output files will be created for each month; otherwise, a single output will be created for the whole year.

8.    Day interval (optional)

The time interval through the year (units: days) used for calculation of sky sectors for the sun map.

The default value is 14 (biweekly).

9.    Hour interval (optional)

Time interval through the day (units: hours) used for calculation of sky sectors for sun maps.

The default value is 0.5.

10. Create outputs for each interval (optional)

Specifies whether to calculate a single total insolation value for all locations or multiple values for the specified interval.

1. Unchecked—A single total radiation value will be calculated for the entire time configuration. This is default.
2. Checked—Multiple radiation values will be calculated for each time interval over the entire time configuration. The number of outputs will depend on the hour or day interval. For example, for a whole year with monthly intervals, the result will contain 12 output radiation values for each location.

11. Z factor (optional)

The number of ground x,y units in one surface z unit.

The z-factor adjusts the units of measure for the z units when they are different from the x,y units of the input surface. The z-values of the input surface are multiplied by the z-factor when calculating the final output surface.

If the x,y units and z units are in the same units of measure, the z-factor is 1. This is the default.

If the x,y units and z units are in different units of measure, the z-factor must be set to the appropriate factor, or the results will be incorrect.

For example, if your z units are feet and your x,y units are meters, you would use a z-factor of 0.3048 to convert your z units from feet to meters (1 foot = 0.3048 meter).

12. Slope and aspect input type (optional)

How slope and aspect information are derived for analysis.

1. FROM_DEM— The slope and aspect rasters are calculated from the input surface raster. This is the default.
2. FLAT_SURFACE— Constant values of zero are used for slope and aspect.

13. Calculation directions (optional)

The number of azimuth directions used when calculating the viewshed.

Valid values must be multiples of 8 (8, 16, 24, 32, and so on). The default value is 32 directions, which is adequate for complex topography.

14. Zenith divisions (optional)

The number of divisions used to create sky sectors in the sky map.

The default is eight divisions (relative to zenith). Values must be greater than zero and less than half the sky size value.

15. Azimuth divisions (optional)

The number of divisions used to create sky sectors in the sky map.

The default is eight divisions (relative to north). Valid values must be multiples of 8. Values must be greater than zero and less than 160.

16. Diffuse model type (optional)

Type of diffuse radiation model.

1. UNIFORM_SKY— Uniform diffuse model. The incoming diffuse radiation is the same from all sky directions. This is the default.
2. STANDARD_OVERCAST_SKY— Standard overcast diffuse model. The incoming diffuse radiation flux varies with zenith angle.

17. Diffuse proportion (optional)

The proportion of global normal radiation flux that is diffuse. Values range from 0 to 1.

This value should be set according to atmospheric conditions. The default value is 0.3 for generally clear sky conditions.

18. Transmittivity (optional)

The fraction of radiation that passes through the atmosphere (averaged overall wavelengths). Values range from 0 (no transmission) to 1 (all transmission).

The default is 0.5 for a generally clear sky.

19. Output direct radiation raster (optional)

The output raster representing the direct incoming solar radiation for each location.

The output has units of watt hours per square meter (WH/m2).

20. Output diffuse radiation raster (optional)

The output raster representing the diffuse incoming solar radiation for each location.

The output has units of watt hours per square meter (WH/m2).

21. Output direct duration raster (optional)

The output raster representing the duration of direct incoming solar radiation.

The output has units of hours.