Label | Explanation | Data Type |
Input raster | The input surface raster. | Raster Layer |
Input point or polyline observer features | The feature class that identifies the observer locations. The input can be point or polyline features. | Feature Layer |
Output above ground level raster (Optional) | The output above-ground-level (AGL) raster. The AGL result is a raster where each cell value is the minimum height that must be added to an otherwise nonvisible cell to make it visible by at least one observer. Cells that were already visible will have a value of 0 in this output raster. | Raster Dataset |
Analysis type (Optional) | The visibility analysis type.
| String |
Use NoData for non-visible cells (Optional) | Value assigned to nonvisible cells.
| Boolean |
Z factor (Optional) | 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). | Double |
Use earth curvature corrections (Optional) | Specifies whether correction for the earth's curvature will be applied.
| Boolean |
Refractivity coefficient (Optional) | The coefficient of the refraction of visible light in air. The default value is 0.13. | Double |
Surface offset (Optional) | A vertical distance to be added to the z-value of each cell as it is considered for visibility. It must be a positive integer or floating-point value. You can select a field in the input observers dataset, or you can specify a numerical value. By default, a numerical field OFFSETB is used if it exists in the input observer features attribute table. You may overwrite it by specifying another numerical field or a value. If this parameter is unspecified and the default field does not exist in the input observer features attribute table, it defaults to 0. | Double; Field |
Observer elevation (Optional) | The surface elevations of the observer points or vertices. You can select a field in the input observers dataset, or you can specify a numerical value. By default, a numerical field SPOT is used if it exists in the input observer features attribute table. You may overwrite it by specifying another numerical field or a value. If this parameter is unspecified and the default field does not exist in the input observer features attribute table, it will be estimated through bilinear interpolation with the surface elevation values in the neighboring cells of the observer location. | Double; Field |
Observer offset (Optional) | A vertical distance to be added to the observer elevation. It must be a positive integer or floating-point value. You can select a field in the input observers dataset, or you can specify a numerical value. By default, a numerical field OFFSETA is used if it exists in the input observer features attribute table. You may overwrite it by specifying another numerical field or a value. If this parameter is unspecified and the default field does not exist in the input observer features attribute table, it defaults to 1. | Double; Field |
Inner radius (Optional) | The start distance from which visibility is determined. Cells closer than this distance are not visible in the output but can still block visibility of the cells between inner radius and outer radius. It can be a positive or negative integer or floating point value. If it is a positive value, then it is interpreted as three-dimensional, line-of-sight distance. If it is a negative value, then it is interpreted as two-dimensional planimetric distance. You can select a field in the input observers dataset, or you can specify a numerical value. By default, a numerical field RADIUS1 is used if it exists in the input observer features attribute table. You may overwrite it by specifying another numerical field or a value. If this parameter is unspecified and the default field does not exist in the input observer features attribute table, it defaults to 0. | Double; Field |
Outer radius (Optional) | The maximum distance from which visibility is determined. Cells beyond this distance are excluded from the analysis. It can be a positive or negative integer or floating point value. If it is a positive value, then it is interpreted as three-dimensional, line-of-sight distance. If it is a negative value, then it is interpreted as two-dimensional planimetric distance. You can select a field in the input observers dataset, or you can specify a numerical value. By default, a numerical field RADIUS2 is used if it exists in the input observer features attribute table. You may overwrite it by specifying another numerical field or a value. If this parameter is unspecified and the default field does not exist in the input observer features attribute table, it defaults to infinity. | Double; Field |
Horizontal start angle (Optional) | The start angle of the horizontal scan range. The value should be specified in degrees from 0 to 360, either as integer or floating point, with 0 oriented to north. The default value is 0. You can select a field in the input observers dataset, or you can specify a numerical value. By default, a numerical field AZIMUTH1 is used if it exists in the input observer features attribute table. You may overwrite it by specifying another numerical field or a value. If this parameter is unspecified and the default field does not exist in the input observer features attribute table, it defaults to 0. | Double; Field |
Horizontal end angle (Optional) | The end angle of the horizontal scan range. The value should be specified in degrees from 0 to 360, either as integer or floating point, with 0 oriented to north. The default value is 360. You can select a field in the input observers dataset, or you can specify a numerical value. By default, a numerical field AZIMUTH2 is used if it exists in the input observer features attribute table. You may overwrite it by specifying another numerical field or a value. If this parameter is unspecified and the default field does not exist in the input observer features attribute table, it defaults to 360. | Double; Field |
Vertical upper angle (Optional) | The upper vertical angle limit of the scan relative to the horizontal plane. The value is specified in degrees and can be integer or floating point. The allowed range is from above -90 up to and including 90. This parameter value must be greater than the Vertical Lower Angle parameter value. You can select a field in the input observers dataset, or you can specify a numerical value. By default, a numerical field VERT1 is used if it exists in the input observer features attribute table. You may overwrite it by specifying another numerical field or a value. If this parameter is unspecified and the default field does not exist in the input observer features attribute table, it defaults to 90. | Double; Field |
Vertical lower angle (Optional) | The lower vertical angle limit of the scan relative to the horizontal plane. The value is specified in degrees and can be integer or floating point. The allowed range is from -90 up to but not including 90. This parameter value must be less than the Vertical Upper Angle parameter value. You can select a field in the input observers dataset, or you can specify a numerical value. By default, a numerical field VERT2 is used if it exists in the input observer features attribute table. You may overwrite it by specifying another numerical field or a value. If this parameter is unspecified and the default field does not exist in the input observer features attribute table, it defaults to -90. | Double; Field |
Return Value
Label | Explanation | Data Type | Output raster | The output raster. The output will either record the number of times that each cell location in the input surface raster can be seen by the input observation locations (the frequency analysis type), or record which observer locations are visible from each cell in the raster surface (the observers type). | Raster |