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Weissberger MED Model

Foliage Link Range Calculator

Estimates the maximum usable distance of a radio link routed through vegetation, combining free-space path loss with Weissberger’s Modified Exponential Decay foliage attenuation model against a link budget built from Meshtastic LoRa modem presets.

Radio

915 MHz
22 dBm

Modem Preset

From the Meshtastic radio settings docs. Link budget assumes 22 dBm TX and 0 dBi antennas — adjusted below for your actual setup.

Foliage Density

Scales Weissberger’s excess vegetation attenuation term. The model’s original baseline data was measured through mixed deciduous/coniferous forest, in leaf.

1.00×
½× lightbaseline2× heavy

Mixed deciduous/coniferous forest (Weissberger baseline)

Antennas & Cabling

2 dBi
2 dBi
0.5 dB
0.5 dB
20 dB

Usable distance through foliage

0m

Total link budget (MAPL): 151.0 dB

Free-space: 84.5 dB (56%)
Foliage: 46.5 dB (31%)
Margin: 20.0 dB (13%)
Margin: 20.0 dB (13%)

Note: distance exceeds Weissberger's validated 400 m range — result is extrapolated.

Path loss vs. distance

Breakdown

Transmitter22 dBm
TX ant.
2 dBi
TX pigtail
−0.5 dB
Free-space
84.5 dB
Foliage
46.5 dB
Margin
20.0 dB
RX pigtail
−0.5 dB
RX ant.
2 dBi

0 m · 151.0 dB total budget

Receiver · Medium Fast-126.0 dBm

Weissberger Modified Exponential Decay model (valid ≈14–400 m foliage depth, 230 MHz–95 GHz). Below 14 m a linear approximation is used. Results are an estimate — real-world foliage, terrain, and Fresnel-zone obstruction vary widely.