Inputs
Formula used
This calculator combines a link budget range with a line-of-sight horizon range. The design radius is the smaller of the two.
- EIRP (dBm) = Tx Power (dBm) + Tx Antenna Gain (dBi) − Feeder Loss (dB)
- Received power: Prx (dBm) = EIRP − FSPL + Rx Gain − (Misc Loss + Clutter Loss)
- Allowable FSPL: FSPL ≤ EIRP + Rx Gain − Losses − (Sensitivity + Fade Margin)
- Free-space path loss: FSPL(dB) = 32.44 + 20log10(dkm) + 20log10(fMHz)
- Radio horizon (approx.): dkm = 3.57 × (√h1 + √h2) × √(k / (4/3))
- Coverage area: A = πr², and effective usable area = A × efficiency
How to use
- Enter your project area, frequency, and antenna parameters.
- Select an environment preset or enter a clutter loss override.
- Set receiver sensitivity and a realistic fade margin.
- Provide base height and UAV altitude to check line-of-sight range.
- Click Calculate Coverage, then export CSV or PDF as needed.
Example data table
| Scenario | Freq (MHz) | Tx (dBm) | Heights (m) | Fade (dB) | Design radius (km) | Stations for 5 km² |
|---|---|---|---|---|---|---|
| Suburban baseline | 2400 | 30 | 20 / 120 | 15 | ~2.50 | ~2 |
| Lower frequency option | 900 | 30 | 20 / 120 | 15 | 3.80 | 1 |
| Urban with higher margin | 5800 | 27 | 30 / 100 | 20 | 1.20 | 6 |
Professional note
This tool is a planning aid for early-stage coverage estimation. Real-world performance depends on terrain, foliage, multipath, antenna orientation, and regulatory limits. Always validate with field measurements.
Coverage planning article
1) Why coverage matters on construction projects
UAV surveys, progress mapping, and safety patrols depend on a stable control and telemetry link. A single dropout can interrupt mission data capture, delay flights, and trigger unplanned landing procedures. Coverage planning converts radio specifications into practical station placement that supports predictable daily operations.
2) Typical input ranges used in practice
Construction deployments often use 900 MHz, 2.4 GHz, or 5.8 GHz links. Lower frequencies generally travel farther, while higher frequencies provide capacity and compact antennas. Base-station heights commonly fall between 10–40 m, and UAV operating altitude is often 60–120 m where permitted.
3) Using link budget to estimate radio range
Link budget compares transmitted power, antenna gains, and losses against receiver sensitivity plus a fade margin. A 10–20 dB margin is frequently used to handle intermittent obstruction and multipath at active sites. The calculator converts allowable free-space path loss into a distance for the selected frequency.
4) Line-of-sight as a hard constraint
Even with strong radio power, curvature and obstructions can cap usable range. The horizon model estimates the maximum line-of-sight distance using the square root of antenna heights. If LoS is limiting, modest increases in mast height can yield meaningful gains without changing radio hardware.
5) Turning radius into base-station counts
A circular radius rarely covers an irregular boundary perfectly, so the tool applies a coverage efficiency factor. Values around 0.70–0.85 are common when overlap is needed for handover and when buildings create shadow zones. The resulting station count provides a rational starting point for layouts, budgets, and test plans.
FAQs
1) What does “design radius” represent?
It is the smaller of radio-limited distance and line-of-sight distance. Planning with the smaller value reduces the risk of overestimating coverage on real sites.
2) Why include a fade margin?
Fade margin accounts for time-varying losses from multipath, partial obstructions, and orientation changes. Without it, a link that “works on paper” can fail during operations.
3) When should I override clutter loss?
Override it when you know your site has unusual blockage, such as tall steel frames, dense equipment, or heavy foliage. Use field observations to choose a realistic extra loss.
4) Does this replace a detailed propagation study?
No. It is intended for early planning and comparisons. Detailed studies may use terrain data, clutter maps, and empirical models to refine range and reliability.
5) What efficiency value should I use?
Start with 0.80 for typical overlap and irregular boundaries. Use 0.70 for complex urban sites and 0.85–0.95 for open areas with minimal obstructions.
6) Why can LoS be smaller than radio range?
At low frequencies or strong link budgets, the radio may support long distances. However, curvature and physical obstructions limit line-of-sight, capping usable range.
7) How can I reduce the number of stations?
Increase base height, improve antenna gain, reduce losses, or choose a lower frequency if allowed. Also verify required fade margin; overly conservative values can inflate station counts.