Plan coverage with line of sight and the Site Planner
1. Check the view with HeyWhatsThat
Section titled “1. Check the view with HeyWhatsThat”HeyWhatsThat computes what’s visible from a point, using terrain data. Enter your proposed repeater site and its height above ground, and it draws the area with line of sight. Meshtastic’s range-test page uses it to plan long links.
2. Predict coverage with the Site Planner
Section titled “2. Predict coverage with the Site Planner”Meshtastic’s Site Planner predicts radio coverage from a node using terrain and radio settings. Use it to compare candidate sites. It works for MeshCore planning too, since the physics is the same; just enter matching radio settings.
3. Mind the Fresnel zone
Section titled “3. Mind the Fresnel zone”A path can be “visible” and still fail if the ground or rooftops intrude into the Fresnel zone, the football-shaped region around the line of sight.
Radius at the midpoint: F1 (m) = 8.656 × √(km ÷ GHz)
| Link length | Midpoint radius at 915 MHz |
|---|---|
| 1 km | ~9 m |
| 5 km | ~20 m |
| 10 km | ~29 m |
| 30 km | ~50 m |
Keep at least 60% of that radius clear of terrain and buildings; 80% is better. Over long links, the curve of the Earth also gets in the way, which is another reason height matters.
4. Test for real
Section titled “4. Test for real”Predictions are estimates. Confirm with a range test before you permanently mount anything.
Sources
Checked on October 18, 2026.