LinkPlanner v4.3.5 - meaning of lines in Profile. Red line always seems to go in the ground


Created a Site, both PTP and PMP links Using LINKPlanner v.4.3.5.  What I would like more information on is what is the RED line represent in the Profile view?  The reason why I'm confused is that no matter what type of LOS I use at some point the red line always goes into the ground before reaching the end point.  The distances are under 3.5 (PTP) and one over 4.5mi (PMP).  There is LOS for the PTP with everything below it.  I have attached some snapshots images showing what I'm referring to.

I can adjust the antenna heights to whatever value, but the red line will not reach the end-points in a straight line.


The red line represents the line of sight to the high points in the profile.

In your  screenshots you can see that the high point (including the worst earth shown in grey) is below the Fresnel zone, so the link is LOS. A LOS link will always have the the red line coming down to a single high point.

When the link is non-line-of-sight then the re may be additional high points shown in the profile, as shown below.



Hi Andrew,

Thanks very much for the explanation and clarifying what those lines meant.