How to Create a Viewshed

How to Create a Viewshed

Viewsheds are a feature present in the Online Map (using V5.3.0 or later), which indicate all the locations in the area surrounding a chosen place that are considered to be Line-of-Sight for a given tower height and subscriber height. To obtain viewsheds please register with the path profile service.

Figure 1 A viewshed on the online mapFigure 1 A viewshed on the online mapCreating a viewshed

  1. Click New Network Site  and place it on the map in the location you desire.
  2. Click on the network site in the Online Map to enable the viewshed menu.
  3. Click either Create Optical LOS Viewshed or Create Radio LOS Viewshed in the top-right corner of the map. See the Viewshed Calculation section for details on Optical and Radio LOS. The viewshed configuration dialog is displayed.
  4. Configure the options in the viewshed configuration dialog. See the Viewshed Configuration section for information about the options in this dialog.
  5. Click OK to start the calculation.

Figure 2 Viewshed progress barFigure 2 Viewshed progress bar

After starting the calculation, a progress bar will be displayed and the buttons will disappear. This is to ensure that only one viewshed is calculated at a time. Multiple calculated viewsheds may be displayed on the map at the same time, although only one may be displayed for each site.

Once the calculation has finished, the menu in the top-right corner of the map will be populated with an entry for this viewshed. This menu contains a list of viewsheds that have been previously calculated. Use the radio buttons to display the desired viewshed image or select “None” to show no image for the site. Before any viewsheds are calculated, only the single item "None" will be shown.

Figure 3 Viewshed map menuFigure 3 Viewshed map menu

For each viewshed entry in the list, the following information is shown:

  1. Tower height
  2. Subscriber height
  3. Viewshed radius
  4. Frequency (for radio LOS viewsheds only)
  5. Clutter (indicates whether clutter was used in the calculation)
  6. The color of the viewshed

Click the red X symbol next to a viewshed in the list to delete it.

Click the "Hide All Viewsheds" button to hide viewsheds for all sites which are currently displaying any. The other two buttons allow the creation of two kinds of viewshed. Press either of these buttons to bring up the viewshed dialog.

Viewshed Configuration

Figure 4 Viewshed Configuration DialogFigure 4 Viewshed Configuration Dialog

The following attributes can be configured before calculating a viewshed.



Tower height

The height of the tower above ground. This does not include clutter.

Subscriber height

The height of the Subscriber above ground + clutter (if selected).


The maximum distance of a Subscriber away from the AP that the calculation will consider.


The frequency to use. This is only available for radio LOS viewsheds.


The display color of the viewshed. The color is only used to differentiate between multiple viewsheds.

Use Clutter?

Tick this to include clutter heights in the calculation. The heights will be taken from the project file.

Viewshed Calculation

Optical LOS viewsheds are calculated by only considering the antenna and tower heights at each end and the ground heights and clutter heights (if included) throughout the entire profile. The tower height (AP) is always the height above ground and the SM height is above ground when clutter is not included and above clutter when it is included. These are typically faster to calculate but will result in more optimistic coverage.

Radio LOS viewsheds will consider the same information as Optical, but determine Line-of-Sight based on a calculated Fresnel zone for each location. Any intersection between terrain, clutter and the Fresnel zone is considered to be Non Line-of-Sight so viewsheds will be pessimistic in Near Line-of-Sight cases and may differ from LINKPlanner profile results.

Viewshed Information

Due to performance reasons, the viewshed calculation will sample the terrain at slightly different locations to the LINKPlanner path profile service which may lead to differences between the two results, for example some areas may be shown as non-line-of-sight in the viewshed region but could still yield a viable link or vice versa.

The underlying terrain and clutter data used to calculate the viewsheds is the same as the Path Profile service. The data is sampled at approximately 30 meter intervals but may be sampled in slightly different locations to the Path Profile service. Where the data resolution exceeds 30 meters, it is resampled to 30 meters but is not any more accurate (this is notably the case for clutter data in Europe and non-US areas). Missing data values are considered to be 0 meters.

At certain zoom levels on the map, parts of the viewshed may appear out of focus - this is due to limitations with the browser scaling the viewshed images, but locations roughly within the 30 meter block of the coloured area will be Line-of-Sight.