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Sun Shadow Frequency

Summary

Calculates the number of times a fixed position on a surface has its direct sight line to the sun obstructed by multipatch features.

Usage

  • The output raster's values represent the number of times a given cell's line of sight to the sun was obscured by a multipatch feature. This means the highest value possible will correspond to the number of times the sun position is being calculated, such that if only one date and time was specified, the largest number for any given cell would be 1, but if 10 times were specified, the maximum possible value would be 10.

  • The sun position will be calculated from the start date and time to the end date and time. To calculate from sunrise, specify the start date without the time. Likewise, to calculate sun position to sunset, specify the end date without the end time. If a time interval is specified, the sun position will be calculated for each day between the start date and end date, and each time between the specified start time and end time incrementing by the time interval.

Syntax

SunShadowFrequency_3d (in_features, ground, out_raster, {cell_size}, {start_time}, {end_time}, {time_interval}, {time_zone}, {dst})
ParameterExplanationData Type
in_features
[in_features,...]

The multipatch features that will constitute the source of obstruction for sunlight.

Feature Layer
ground

The ground surface that defines the positions where sunlight obstruction will be evaluated.

Raster Layer
out_raster

The output raster whose cell values reflect the number of times the corresponding ground height position was obstructed by the input features.

Raster Dataset
cell_size
(Optional)

The cell size of the output raster.

Linear Unit
start_time
(Optional)

The date and time sun position calculations will begin. If only the date is provided, the start time will be presumed as beginning from sunrise for that day. The default value is set to the date and time corresponding to when the tool is opened in the application or executed in Python.

Date
end_time
(Optional)

The date and time sun position calculations will end. If only the date is provided, the end time is defined by sunset for the specified day.

Date
time_interval
(Optional)

The interval used to calculate sun positions from the start date and time to the end date and time.

Time Unit
time_zone
(Optional)

The time zone that corresponds with the specified input times used to determine the relative position of the sun. The list of available values is defined by the operating system but will default to the time zone of the current time on the computer.

String
dst
(Optional)

Specifies whether the specified times have been adjusted for daylight saving time.

  • DSTThe input times are adjusted for daylight saving time.
  • NO_DSTThe input times are not adjusted for daylight saving time. This is the default.
Boolean

Code sample

SunShadowFrequency example 1 (Python window)

The following sample demonstrates the use of this tool in the Python window.

import arcpy
arcpy.env.workspace = 'd:\\data'
arcpy.ddd.SunShadowFrequency('Buildings.shp', 'DEM.tif', 'June_Shade.tif',
                             '4 Feet', '6/1/2018 10:00 AM', '6/30/2018 4:00 PM',
                             '15 Minutes', 'Pacific Standard Time', 'NO_DST')

Licensing information

  • ArcGIS Desktop Basic: Requires 3D Analyst
  • ArcGIS Desktop Standard: Requires 3D Analyst
  • ArcGIS Desktop Advanced: Requires 3D Analyst

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