Satlink Planner

A mobile-first web app that, given any satellite (NORAD ID or name) and user location (via address or map), returns:

• Upcoming LEO pass predictions
• Link margin/SNR vs time
• Timeline chart, ICS export, PDF report

Security

• No inline tokens or keys in source
• No exposed DB or secrets in client; Google Maps key is injected at runtime via /api/config/public
• All inputs validated/sanitized via FastAPI/Pydantic

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Quickstart (Local)

1. Copy .env.example to .env and set GOOGLE_MAPS_API_KEY (public key).

2. Install backend deps and run dev servers:

make dev

• Backend: http://localhost:8000
• Frontend: http://localhost:5173 (proxy to backend under /api)

Link Budget (simplified)

• Free-space loss: Lfs[dB] = 92.45 + 20 log10(f[GHz]) + 20 log10(R[km])
• EIRP[dBW] = Ptx[dBW] + Gtx[dBi]
• Prx[dBW] = EIRP + Grx - Lfs - L_atm - L_rain - L_point
• kTB[dBW] = -228.6 + 10 log10(T[K]) + 10 log10(B[Hz])
• SNR[dB] = Prx - (kTB + NF)

Sample TLEs

A small set is under data/sample_tles.json.

Notes

• This implementation uses a simplified TEME->ECEF rotation (GMST), which is adequate for planning purposes but not for precision orbit determination.
• All times are treated as UTC in the API; the frontend renders local-time labels.