Frequency

Frequency MHz

Coverage: 30 to 1300 MHz.

Coverage: 30 to 1300 MHz. A repeater can have its own frequency in the Repeaters panel.

Polarization

Station A (transmitter)Repeater

Lat Lon

Antenna height m above ground Power W Antenna gain dBi Cable Cable length Extra loss dB

Antenna pattern

MSI/Planet, Radio Mobile .ant

Vertical pattern Down-tilt °

Azimuth ° Beamwidth (−3 dB) ° Front-to-back dB

Mobile station (receiver)

Antenna height m above ground Antenna gain dBi Cable Cable length Extra loss dB

Receiver threshold dBm

Coverage

Radius km Resolution

Station B (receiver)

Lat Lon

Antenna height m above ground Antenna gain dBi Cable Cable length Extra loss dB

Receiver threshold dBm

Cable loss: typical catalogue attenuation (dB per 100 m at 20 °C) at the working frequency. Extra loss: connectors, adapters, arrestor, filters.

Propagation model (ITM, Longley-Rice)

Climate Surface refractivity N-units Ground Variability mode Time % Locations % Situations %

Click the map to place A, then B; drag the markers to move them. Everything is computed in your browser.

Drag the marker to move the repeater. Click the map to read the level at a point and open the profile to it. Computed in your browser, in parallel.

Repeaters are listed under the map; drag their numbered markers to move them. Click the map to read the levels at a point and open the profile from the best repeater. Computed in your browser, in parallel.

Next click places: A

Export:

Repeaters

Show

On		Name	Lat	Lon	Ground m a.s.l.	Height m	Power W	Gain dBi	Cable	Length		Extras dB	Pattern	Vertical	Tilt °	Az °	Beam °	F/B dB	MHz

"+ Add repeater" places a new one at the map centre. Empty MHz = the link frequency. Ground = terrain above sea level at the site (Copernicus DEM, read-only); Height = antenna above ground. Changing the view does not recompute; after editing press "Compute coverage".

Path profile

Terrain drawn on the curved earth (effective radius from the surface refractivity), straight line of sight, first Fresnel zone (shaded) and its 60 % boundary (dashed). Red: terrain inside the 60 % zone. The dot marks the worst clearance.

Results

Surface reflection (ITU-R P.530)

The reflected wave is searched on the terrain profile: smooth areas (water, plains, even slopes) seen by both antennas where the angles of the two rays are equal. Effective earth factor k from 2/3 to infinity; the median k comes from the surface refractivity. Not added to the received level above: ITM already includes an average ground reflection. Not included: antenna discrimination (narrow-beam antennas weaken the reflected wave) and reflections from the sides of the path.