Validation
Published magnitudes
The catalogue models against magnitudes published for the real objects.
npm run validate, or Validation on published magnitudes in the Satellite tab, simulates each catalogue model in the conditions that define a published magnitude.
Reference conditions
Section titled “Reference conditions”Whatever the interface shows: Haute-Provence Observatory, the 2026 equinoxes and solstices at 22:00 UTC (the Sun’s declination changes the attitude of nadir-pointing bodies relative to the Sun), the preset attitude and materials of each model, no Earth’s shadow, no atmosphere.
Definitions reproduced
Section titled “Definitions reproduced”Quicksat intrinsic magnitude (M. McCants)
1,000 km, full phase, “brightest likely” magnitude (quicksat.mag, definitions). Simulated magnitudes at 30, 50, 70, 90 and 110° of phase and three phase-plane tilts are brought to full phase with the illuminated-fraction law (1 + cos φ) / 2 (50 % illuminated = +0.75 mag, the 0.8 mag difference McCants gives), averaged, then made 0.7 mag brighter (the “brightest likely” vs average difference McCants gives).
Characteristic magnitude (Mallama & Respler 2022)
Mean brightness when the satellite is at the zenith at the end of astronomical twilight (Sun 18° below the horizon, phase ≈ 72°), at its operational altitude (550 km) — arXiv:2210.17268.
Mean magnitude at 1,000 km
Mean of the magnitudes adjusted to 1,000 km, over phases of 40 to 110°.
Results
Section titled “Results”| Object | Published | Definition | Simulated − published |
|---|---|---|---|
| ISS | −2.5 ± 0.7 | Quicksat | −0.02 |
| Hubble | 1.5 ± 0.7 | Quicksat | +0.88 |
| SL-16 rocket bodies (22220, 22285, 22566, 22803) | 2.0 ± 0.7 | Quicksat | −0.39 |
| Falcon 9 rocket body (37253, 2010 v1.0 stage) | 2.0 ± 0.8 | Quicksat | −0.33 |
| Starlink Post-VisorSat (v1.5) | 5.5 ± 0.3 | Characteristic | −1.77 |
| Starlink V2 Mini, not mitigated | 5.2 ± 0.6 | Mean at 1,000 km, derived | +1.68 |
Reading
Section titled “Reading”- The ISS and the rocket bodies are within 0.4 mag.
- Hubble is 0.9 mag too faint: the model’s silver MLI is very specular.
- The two Starlink models miss by about 1.7 mag, in opposite directions: SpaceX’s brightness-mitigation attitudes, films and visors are not modelled, and the model’s arrays track the Sun.
- The default materials are not recalibrated: one magnitude per family does not justify it. Several measured series fitted together would.
The Starlink V2 Mini value is derived from Mallama et al. 2023: 7.87 (mean at 1,000 km in mitigation mode) − 2.5 log10 12 (the published luminosity factor of the non-mitigated mode). The phases of the observations are not published.