How to add obstructions and edit Path Profiles

Manual editing of path profiles in LINKPlanner

There can be obstructions in the link path which can affect the signal quality. LINKPlanner makes it easy to edit the path profile for a link to alter the terrain and obstructions heights at single or multiple points. It also allows copy-paste of the profile, editing a profile and the addition of range points.

Adding Obstructions

Once the path profile has been obtained for the link then it can be manually updated for obstructions.

Select the specific PTP/PMP link in the navigation tree to view the link page.

Figure 1 Link Page

The link page will display the profile visualization chart.

Figure 2 Profile Visualization Chart

Double click on the profile visualization chart, the Profile Editor page will be displayed (See Figure 3 ). Enter or update the range or obstruction height as required, as shown in Figure 3, a 4 m high obstruction at range 0.501 km and a 3.5 m high obstruction at range 0.678 km have been added.


Figure 3 Profile Editor

The profile graph is updated to include the obstructions as green areas above the terrain. (See Figure 4)

Figure 4 Updated Profile

Editing multiple points

An obstruction of roughly constant height (for example a forest or tall buildings) may extend for some distance along the path. These can be added to the profile by editing multiple points at the same time.

There are two methods for selecting multiple points.

  1. Open the profile editor and select specific points by dragging the mouse cursor in the editor, this will highlight affected points in the graph. (Note: To adjust the obstruction height, ensure only the obstruction column is selected. To adjust the terrain height select only the terrain height column)
  2. Open the profile editor and select only the obstruction by dragging the mouse cursor in the graph or use Alt+Drag to select only the terrain.

Figure 5 Selecting multiple points to edit

To set the same height for multiple points, select those points in the profile editor and type the new height. Press enter and that height will be entered for all those points. To adjust the heights for multiple points so that there is a constant gradient, set the heights at either end of the range, then select the range and click the Straight Line image016.pngbutton from the profile editor tool menu.


Figure 6 Editing multiple profile points

Expert Tip - If a tall building partially obstructs the Fresnel zone by cutting vertically into one side, treat it as though it cuts horizontally into the bottom of the Fresnel zone. For example, if it extends 3 m into the right hand side of the zone, enter it as an obstruction, with a height which extends 3m into the bottom of the Fresnel zone.


Adding new range points

To insert a new range point in between two of the existing profile points, click on the Add Point image013.jpg button in the Profile Editor.


The range along the path needs to be specified along with the terrain height at that point and the obstruction height. The height can also be estimated for either the terrain or the obstruction by pressing the Estimate height button image016.png , this will enter the height based on the points either side of the new one.

Deleting points

The points can also be removed by selecting them and pressing the Delete Points image017.jpg button, any points except the first and last can be deleted.

Copy a Path Profile

There are two methods for copying a path profile:

  1. Right-click on the Profile Visualization Chart and choose Copy from the pop-up menu.
  2. Open the Profile Editor and click the copy image018.png button.

 The copied data can be pasted directly into a spreadsheet.


Editing a Profile in a Spreadsheet

LINKPlanner can export the profile data to a CSV file. This will automatically open in the appropriate software. To export the profile, open the Profile Editor and click the spreadsheet button. Once the appropriate changes have been made to the profile, copy the information and paste it back into LINKPlanner.


Figure 7 Editing profile points in the spreadsheet


LINKPlanner will use the units that are defined in the header row of the path profile when it is pasted into a project. If the header row is missing or if the units are not recognized then the preferred units will be used. If the new profile length does not match the link length then LINKPlanner will either truncate the data to the appropriate length or duplicate the last set of data at the end on the link.

Pasting a Path Profile

There are two methods for pasting a path profile:

  1. Right-click on the Profile Visualization Chart and choose Paste from the pop-up menu.
  2. Open the Profile Editor and click the paste image021.png button