ViewShed Parameters

If you choose to perform viewshed operations at selected point feature locations, the viewshed calculation values will be initialized from attributes and attribute values of the point feature.

The values selected on the dialog will be used, except when one of the following attributes is present with a value to override what was selected on the dialog (this allows you to batch calculate viewsheds at different locations with different parameters):

  • OFFSETA or TRANSMITTER_HEIGHT - height above ground in meters (or feet if 'ft' in value) for transmitter (observation point)
  • OFFSETA_MSL (or OFFSETA_MS if coming from a Shapefile) - height above sea level in meters (or feet if 'ft' in value) for transmitter (observation point)
  • OFFSETB or RECEIVER_HEIGHT - height above ground in meters (or feet if 'ft' in value) for receiver
  • OFFSETB_MSL (or OFFSETB_MS if coming from a Shapefile) - height above sea level in meters (or feet if 'ft' in value) for receiver
  • AZIMUTH1 or SWEPT_ANGLE - start angle for viewshed (0 is north, 90 is east, etc.)
  • AZIMUTH2 or END_ANGLE - end angle for viewshed (0 is north, 90 is east, etc.)
  • SWEPT_ANGLE - number of degrees to sweep clockwise. Value must be greater than 0 and up to 360.0. You would use AZIMUTH2 or SWEPT_ANGLE, but not both
  • RADIUS2 or RADIUS- outer radius in meters of viewshed calculation. You can include units after the value to specify something other than meters, like '3 km' or '5 miles'
  • RADIUS1 - inner radius in meters of viewshed calculation (default is 0, which does entire radius). You can include units after the value, see RADIUS2 for details.
  • VERT1 - The top of the vertical angle to limit the scan (receiver angle range top value)
  • VERT2 - The bottom of the vertical angle to limit the scan (receiver angle range bottom value)
  • FRESFREQ - provides the frequency for a Fresnel zone in GHz
  • COLOR - specifies the color to use for the covered part of the viewshed. A number of formats are supported, including "RGB(red,green,blue)", hex formatting like "#RRGGBB" or "XRRGGBB", or just an integer representing the 24-bit color.

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