Is this flight software?

No. SIDUS models are educational reimplementations. Cross-check before any flight decision.

Diffraction resolution / GSD

θ ≈ 1.22 λ/D and ground sample distance at range.

SIDUS educational calculator. Category satellite. Tags: analysis, earth-observation, RF, satellite. Pure SI. Not flight software.

θ ≈ 1.22 λ/D

Diffraction resolution / GSD

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.
SIDUS pure-SI implementation (sidus.tools): Local pure-function implementations in src/lib/physics (educational, independent reimplementation).

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