Label | Explanation | Data Type |

Input Elevation Surface | The elevation surface that will be used for calculating the viewshed. If the vertical unit of the input surface is different from the horizontal unit, such as when the elevation values are represented in feet but the coordinate system is in meters, the surface must have a defined vertical coordinate system. This is because the tool uses the vertical (z) and horizontal (x,y) units to compute a z-factor for the viewshed analysis. Without a vertical coordinate system, and having no z-unit information available, it is assumed that the z-unit is the same as the x,y unit. The result is an internal z-factor of 1.0 will be used for the analysis, which may give unexpected results. The elevation surface can be integer or floating point. | Raster Layer; Image Service; String |

Observer Features | The point features that represent the observer locations when calculating the viewsheds. | Feature Set |

Output Name | The name of the output raster service. The default name is based on the tool name and the input layer name. If the layer name already exists, you will be prompted to provide another name. | String |

Optimize For (Optional) | Specifies the optimization method that will be used to calculate the viewshed. - Speed—Processing speed will be optimized, trading some accuracy in the result for better performance. This is the default.
- Accuracy—Accuracy in the results will be optimized, at the expense of a longer processing time.
| String |

Maximum Viewing Distance Type (Optional) | Specifies how the maximum viewing distance will be determined. If you change the type from Distance to Field, the Maximum Viewing Distance parameter will change to Maximum Viewing Distance Field. - Distance—The maximum distance will be determined by the value you specify. This is the default method.
- Field—The maximum distance for each observer location will be determined by the values in a field you specify.
| String |

Maximum Viewing Distance (Optional) | The cutoff distance that will be used where the computation of visible areas stops. Beyond this distance, it is unknown whether the observer points and the other objects can see each other. The unit values are Kilometers, Meters, Statute Miles, International Yards, International Feet, US Survey Miles, US Survey Yards, and US Survey Feet. The default value is 9 statute miles. | Linear Unit |

Maximum Viewing Distance Field (Optional) | The field containing the maximum viewing distance for each observer. The values contained in the field must be in the same unit as the x,y unit of the input elevation surface. The maximum viewing distance is a cutoff distance where the computation of visible areas stops. Beyond this distance, it is unknown whether the observer points and the other objects can see each other. | Field |

Minimum Viewing Distance Type (Optional) | Specifies how the minimum visible distance will be determined. If you change the type from Distance to Field, the Minimum Viewing Distance parameter will change to Minimum Viewing Distance Field. - Distance—The minimum distance will be determined by the value you specify. This is the default method.
- Field—The minimum distance for each observer location will be determined by the values in a field you specify.
| String |

Minimum Viewing Distance (Optional) | The distance that will be used where the computation of visible areas begins. Cells on the surface closer than this distance are not visible in the output but can still block visibility of the cells between the minimum and maximum viewing distance. The unit values are Kilometers, Meters, Statute Miles, International Yards, International Feet, US Survey Miles, US Survey Yards, and US Survey Feet. | Linear Unit |

Minimum Viewing Distance Field (Optional) | The field containing the minimum viewing distance for each observer. The values contained in the field must be in the same unit as the x,y-unit of the input elevation surface. The minimum viewing distance defines where the computation of visible areas begins. Cells on the surface closer than this distance are not visible in the output but can still block visibility of the cells between the minimum and maximum viewing distance. | Field |

Viewing distances are 3D (Optional) | Specifies whether the minimum and maximum viewing distance parameter values will be measured in 3D or 2D. A 2D distance is the simple linear distance measured between an observer and the target using their projected locations at sea level. A 3D distance provides a more realistic value by taking their relative heights into consideration. - Checked—The viewing distance will be measured in 3D distance.
- Unchecked—The viewing distance will be measured in 2D distance. This is the default.
| Boolean |

Observers Elevation Type (Optional) | Specifies how the elevation of the observers will be determined. If you change the type from Elevation to Field, the Observers Elevation parameter will change to Observers Elevation Field. - Elevation—The observer elevation will be determined by the value you specify. This is the default method.
- Field—The elevation for each observer location will be determined by the values in a field you specify.
| String |

Observers Elevation (Optional) | The elevation that will be used for the observer locations. If this parameter is not specified, the observer elevation will be obtained from the surface raster using bilinear interpolation. If this parameter is set to a value, that value will be applied to all the observers. To specify different values for each observer, set this parameter to a field in the input observer features. The unit values are Kilometers, Meters, Statute Miles, International Yards, International Feet, US Survey Miles, US Survey Yards, and US Survey Feet. | Linear Unit |

Observers Elevation Field (Optional) | The field containing the elevation for the observers. The value contained in the field must be in the same unit as the z-unit of the input elevation surface. If this parameter is not specified, the observer elevation will be obtained from the surface raster using bilinear interpolation. | Field |

Observers Height Type (Optional) | Specifies how the height of the observers will be determined. If you change the type from Height to Field, the Observers Height parameter will change to Observers Height Field. - Height—The observer height will be determined by the value you specify. This is the default method.
- Field—The height for each observer location will be determined by the values in a field you specify.
| String |

Observers Height (Optional) | The height that will be used for the observer locations. The default value is 6 international feet. | Linear Unit |

Observers Height Field (Optional) | The field containing the height for the observers. The value contained in the field must be in the same unit as the z-unit of the input elevation surface. | Field |

Target Height Type (Optional) | Specifies how the target height will be determined. If you change the type from Height to Field, the Target Height parameter will change to Target Height Field. - Height—The target height will be determined by the value you specify. This is the default method.
- Field—The height for each target will be determined by the values in a field you specify.
| String |

Target Height (Optional) | The height of structures or people on the ground that will be used to establish visibility. The result viewshed are those areas where an observer point can see these other objects. The converse is also true; the other objects can see an observer point. | Linear Unit |

Target Height Field (Optional) | The field containing the height for the targets. The value contained in the field must be in the same unit as the z-unit of the input elevation surface. | Field |

Above Ground Level Output Name (Optional) | The name of the output above-ground-level (AGL) raster. The AGL result is a raster in which 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 be assigned 0 in this output raster. | String |

Vertical Error (Optional) | The amount of uncertainty (the root mean square (RMS) error) in the surface elevation values. It is a floating-point value representing the expected error of the input elevation values. When this parameter is assigned a value greater than 0, the output visibility raster will be floating point. | Linear Unit |

Refractivity Coefficient (Optional) | The coefficient of the refraction of visible light in air. The default value is 0.13. | Double |

Horizontal Start Angle (Optional) | The start angle of the horizontal scan range. Provide the value in degrees from 0 to 360 with 0 oriented to north. The value can be integer or floating point. The default value is 0. You can select a field in the input observer features, or you can provide a numerical value. | String |

Horizontal End Angle (Optional) | The end angle of the horizontal scan range. Provide the value in degrees from 0 to 360 with 0 oriented to north. The value can be integer or floating point. The default value is 360. You can select a field in the input observer features, or you can provide a numerical value. | String |

Vertical Upper Angle (Optional) | The upper vertical angle limit of the scan relative to the horizontal plane. Provide the value in degrees from above -90 up to and including 90. The value can be integer or floating point. The default value is 90 (straight up). You can select a field in the input observer features, or you can provide a numerical value. | String |

Vertical Lower Angle (Optional) | The lower vertical angle limit of the scan relative to the horizontal plane. Provide the value in degrees from -90 up to but not including 90. The value can be integer or floating point. The default value is -90 (straight down). You can select a field in the input observer features, or you can provide a numerical value. | String |

### Derived Output

Label | Explanation | Data Type |

Output Raster | The output viewshed raster. | Raster Layer |

Output Above Ground Level Raster | The output above ground level raster. | Raster Layer |