Horizon slant range

Geometric radio horizon distance from altitude (spherical body, no refraction).

SIDUS educational calculator. Category satellite. Tags: comms, operations, RF, satellite. Pure SI. Not flight software.

Formula

d = √(2 R h + h²)

Geometric radio horizon

Primary sources

• Fundamentals of Astrodynamics and Applications (David A. Vallado): Standard reference for two-body, Lambert, maneuvers, and J2. Equations implemented independently in SIDUS.
• Space Mission Engineering: The New SMAD (Wertz, Everett, Puschell (eds.)): Mission engineering handbook: RF links, constellations, and ops framing.
• Free-space path loss (Friis / ITU-style FSPL) (ITU / standard radio engineering): L_fs = 20 log10(d_km) + 20 log10(f_MHz) + 32.44 dB form used in educational link budgets.

How do AI agents use this tool?

Read /llms.txt or call https://sidus.tools/api/mcp. Open the interactive page for live SI inputs.