What is the Maximum Range I can Get?

[abcd567]

INTRODUCTION
The Maximum Range achievable at any location depends on
(1) Curvature of earth
(2) The  terrain around that location. Terrain plays a very important role as hills & changes in ground level will restrict maximum range.

This is due to the fact that propagation of radio waves in GHz/Microwave range is line of sight. The range is therefore limited by curvature of earth, and is about 250 nautical miles / 450 km for an ideal condition of perfectly level terrain. Hills &  rise in ground levels further restrict maximum range to less than 250 nautical miles / 450 km.

FIND YOUR MAXIMUM POSSIBLE RANGE
In order to determine what maximum possible range you can get at your location, follow the steps below:
(1) Visit the site http://www.heywhatsthat.com
(2) Select tab "new panorama"
(3) Enter your latitude and longitude
(4) Enter your elevation (=enter elevation of your antenna)
(5) Enter title
(6) Hit "submit request" button
(7) Wait and view sponsor's advertisement while panorama is generated
(8) When panorama is generated, scroll down to map, and click "up in the air" tab on top right of map.
(9) Zoom-out the map till you see two circular curves in blue & yellow colors, showing maximum distance of aircrafts at 10,000 feet & 30,000 feet elevation.
(10) Below the map you will see text boxes light yellow & light blue with default aircraft heights 10,000 feet & 30,000 feet. Change these to suite your requirements, and press "Enter" button. The two curves will modify to new height figures you have entered. I recommend to use 10,000 & 45,000 feet, as normally commercial flights are 45,000 feet & below.








REFRACTION OF RADIO WAVES
The layers of air cause refraction of radio waves, and radio line of sight may extend beyond optical line of sight by as much as 50 nautical miles. Your maximum possible range for planes flying between Flight Levels 400 (40,000 feet) and 450 (45,000 feet) therefore may be up to about 50 nautical miles more than the maximum possible range shown by the curves you got from heywhatsthat.com site.






ANTENNA LOCATION
To achieve your maximum possible range, your antenna should be installed at a height where it is above trees & houses surrounding it, and can "see" the horizon.


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[Tom N Jerry]

This thread is very useful. Deserves to be made Sticky by the Forum Admin.