Coverage input form
Example data table
| Scenario | Altitude (km) | Min elevation (deg) | Satellites | Coverage area (km²) | Earth coverage (%) | Target completion (%) |
|---|---|---|---|---|---|---|
| LEO broadband example | 550.00 | 10.00 | 12 | 8,652,703.63 | 1.70 | 100.00 |
| MEO navigation example | 20,200.00 | 10.00 | 8 | 152,692,819.56 | 29.94 | 100.00 |
| GEO regional beam example | 35,786.00 | 5.00 | 3 | 194,808,935.01 | 38.19 | 100.00 |
Formula used
1) Edge central angle: ψ = acos((Re / (Re + h)) × cos(e)) − e
2) Slant range: ρ = √((Re + h)² − (Re × cos(e))²) − Re × sin(e)
3) Surface footprint radius: r = Re × ψ
4) Coverage area on Earth: A = 2 × π × Re² × (1 − cos(ψ))
5) Earth coverage percentage: %Earth = (A / (4 × π × Re²)) × 100
6) Orbital period estimate: T = 2 × π × √((Re + h)³ / μ), where μ = 398600.4418 km³/s²
7) Effective constellation coverage: Aeffective = min(Aearth, A × N × η), where N is satellite count and η is the efficiency factor.
How to use this calculator
- Choose a preset orbit or enter a custom satellite altitude.
- Set the minimum elevation angle allowed at the ground terminal.
- Keep Earth radius at 6371 km unless you need another planetary body.
- Enter the number of satellites in the planned constellation.
- Use constellation efficiency to discount overlap and spacing losses.
- Provide the target service area you want to cover.
- Click Calculate Coverage to place results above the form.
- Review the graph, example table, and exports for reporting.
Frequently asked questions
1) What does minimum elevation angle change?
It trims the outer edge of the visible footprint. A higher angle usually improves link margin and blockage resistance, but it reduces surface coverage area and footprint radius.
2) Why does higher altitude increase coverage?
A higher orbit sees more of Earth at once, so the edge central angle grows. That produces a larger footprint diameter and a larger spherical-cap coverage area.
3) Is full Earth coverage realistic from simple area division?
Not exactly. The ideal satellite count is a geometric lower bound. Real constellations need extra spacecraft for overlap, polar access, inclination, handoff, downtime, and revisit targets.
4) What does constellation efficiency represent?
It is a planning factor for overlap losses and imperfect spacing. Lower efficiency means your constellation produces less unique useful area than pure geometry suggests.
5) Can I use this for GEO, MEO, and LEO?
Yes. The calculator accepts any positive altitude and includes common defaults. It works best for first-pass engineering studies before deeper orbital access and link-budget analysis.
6) Does the calculator include terrain or weather?
No. It is a pure geometric coverage model. Local masking, rain fade, antenna patterns, regulations, and gateway architecture must be checked separately.
7) Why is slant range important?
Slant range affects propagation delay and free-space loss. Even when two systems share altitude, different elevation constraints can change the longest path the signal must travel.
8) What is the target service completion percentage?
It compares the effective unique constellation area against your entered target area. It helps estimate whether a planned fleet can cover a region of interest.