Diversity Path Profiles
Q: How can I draw the line of sight and Fresnel zone for a space-diversity system in HDPath™?
A: With TAP6.0.2257 or later and a Maintenance Subscription date of August 31, 2008, or later, you can add the diversity path to the profile.
Note that all values in this example are for demonstration purposes only. You should determine appropriate settings for your application.
For example, suppose you have a path profile for a microwave system as shown:
A space diversity system is indicated by the antenna height shown for the “Receiver Antenna (Diversity) antenna height, showing the separation between the primary and the diversity antennas.
The line of sight and Fresnel zone for the transmitter frequency are shown, using the Fresnel number and ratio specified in the Fresnel section of the Path Settings:
To add the line of sight and the Fresnel zone to the diversity antenna, click the Configuration menu and then click “Draw Diversity LOS”
A checkbox beside the item in the menu indicates that the option is selected.
You will be prompted for the Fresnel zone number to use for the diversity plot. This may be the same or different from the primary Fresnel information. For example, you could enter a value of 2 for the second Fresnel zone:
Click the OK button to continue.
You will then be prompted for the Fresnel ratio to use for the diversity plot. For example, you could enter a value of 1.0. This would draw the full second Fresnel zone in this example (1F2).
Click the OK button to continue.
Now the profile will show both the primary and diversity line of sight and Fresnel zone information. The "Draw Diversity LOS" setting will remain in effect until you select the Configuration menu again and click Draw Diversity LOS. The option is ignored on paths with no diversity antenna information for the receiver Fixed Facility.
You can use the Box Zoom function to inspect the plot in more detail. Click the Box Zoom button.
Hold down the left mouse button and drag a box over the part of the profile you want to zoom to:
If you drag the box slightly off of the profile graphic you can include the site at the end.
You can see the separate lines of sight and Fresnel zones to the primary and diversity antennas:
The box zoom function can also be useful at locations along the path to examine the obstructions or possible reflection points based on the two Fresnel plots and the terrain.
To cancel the box zoom and return to the full path, right click on the profile graphic:
The profile will be restored to the entire path. The path can also be drawn with multiple earth curvature values by entering the values, separated by spaces, in the “Eff Curve” section of the Path Settings:
Click the pencil icon Draw button to draw the path with multiple earth curvature values and both the primary and diversity Fresnel zones:
The path is redrawn with all the information:
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Copyright 2008 by SoftWright LLC