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How To: Control the visibility analysis in the Viewshed tool

Summary

Instructions provided explain how to specify parameters for visibility when using the Viewshed tool.

Procedure

Nine items in the observer feature dataset's attribute table can be used to control the viewshed analysis. These items are SPOT, OFFSETA, OFFSETB, AZIMUTH1, AZIMUTH2, VERT1, VERT2, RADIUS1, and RADIUS2.

Note:
ArcGIS Desktop help contains useful information about how these parameters work. The purpose of this article is to demonstrate how to set up a point shapefile attribute table to control the viewshed analysis.
For more information on the function of each parameter please see ArcGIS Desktop.

To control the nine parameters listed above, a numeric field must be added to the attribute table for each parameter that requires adjusting.

Each field needs to be named appropriately using one of the following keywords:

SPOT, OFFSETA, OFFSETB, AZIMUTH1, AZIMUTH2, VERT1, VERT2, RADIUS1, and RADIUS2

The type of field can be defined as Long Integer, Short Integer, Float, or Double. The field should be defined with enough scale and precision to accommodate values for the particular parameter.