Would You Like to Calculate the Path Distance Based on Latitude & Longitude?
Yes
No
If No, Enter the Distance Between Antenna Sites
If Yes, Answer the Following FOUR Questions
Transmitter Site Latitude
°
'
" Positive is North
Transmitter Site Longitude
°
'
" Negative is West
Receiver Site Latitude
°
'
" Positive is North
Receiver Site Longitude
°
'
" Negative is West
Notes
AGL Above Ground Level. Height above common ground to the midpoint of the radiating antenna.
AMSL Above Mean Sea Level. Height referenced above sea level, or zero elevation.
For sealed Yagi antennas, radome loss is usually taken into account in the antenna's specified gain.
Antenna height and diversity antenna height should be measured from the antenna's center-of-radiation, usually the midpoint of the antenna.
Miscellaneous path losses are caused by ground reflections, atmospheric absorption, interference, rain/fog, billboards, vegetation, knife-edge diffraction, small farm animals, etc.
Diversity antenna cable type is assumed the same as the main receiver's.
Dispersive fade margin is provided by your radio's manufacturer, and is determined by the type of modulation, effectiveness of any equalization in the receive path, and the multipath signal's time delay. Dispersive fade margin characterizes the radio's robustness to dispersive (spectrum-distoring) fades.
External interference fade margin is receiver threshold degradation due to interference from external systems.
Adjacent channel interference fade margin accounts for receiver threshold degradation due to interference from adjacent channel transmitters in one's own system.
Example standard deviation of the terrain elevations: 6 meters - for smooth and over-water terrain, 15 meters - for average terrain with some roughness, 43 meters - for mountainous or very rough terrain.
The K Factor accounts for refraction of radio waves close to the surface of the Earth. For antenna towers less than a couple of thousand feet above the surface, a K Factor of 4/3 is usually adequate for most line-of-sight calculations over average terrain. A K Factor of 1.0 is equal to the true Earth radius, a K Factor of Infinity is equal to a flat Earth.
