VERIFICATION & BENCHMARKS
Physics Model Validation & Flight Telemetry Comparison
Every interactive Lab tool and computed MDX table in nadir lab. executes deterministic TypeScript physics modules in lib/physics/. Below is a live build-time comparison between our first-order models and published aerospace references or flight telemetry.
| Benchmark Case | nadir lab. Computed Value | Published / Flight Reference | Primary Source / Standard | Agreement |
|---|---|---|---|---|
| 525 km circular orbital period & J₂ SSO inclination (lib/physics/orbit.ts) | 95.13 min / 97.50° | 95.13 min / 97.50° | Vallado (2013), Fundamentals of Astrodynamics, 4th ed., Eqs. 2-36 & 11-11 | 0.00% (Validated) |
| Cylindrical shadow eclipse fraction at 525 km, β = 0° (lib/physics/orbit.ts) | 0.375 (35.7 min) | 0.375 (35.6 min) | Wertz, Everett & Puschell (2011), Space Mission Engineering: The New SMAD, Eq. 11-9 | 0.06% (Validated) |
| Grizu-263A (237 g, B = 0.039 m²/kg) decay from 525 km under observed NOAA F10.7 (lib/physics/decay.ts) | 774 d (2.12 yr; high–mod const: 0.91–2.29 yr) | 628 ± 1 d (1.72 yr; launch 13 Jan 2022 → re-entry 2 Oct 2023 SATCAT / 3 Oct 2023 SatNOGS) | CelesTrak SATCAT (CATNR 51025) + NOAA SWPC observed monthly F10.7 + SQ-R-001 §5.8 | +23.3% a priori (B_eff = 0.0502 matches 628 d) |
| Thermospheric density at 500 km & 525 km: Kennewell (F10.7=140, Ap=12) vs. Vallado Table 8-4 (lib/physics/atmosphere.ts) | 500 km: 5.71 × 10⁻¹³ · 525 km: 3.68 × 10⁻¹³ kg/m³ (extrapolated >500 km) | 500 km: 6.97 × 10⁻¹³ · 525 km: 4.71 × 10⁻¹³ kg/m³ | Kennewell (1999, ASWS, valid 180–500 km) vs. Vallado (2013), 4th ed., Table 8-4, p. 562 | −23% at 500 km (model comparison; extrapolated >500 km) |
| 1U CubeSat (1.33 kg, B = 0.0248 m²/kg) lifetime at 525 km, F10.7 = 140 sfu (lib/physics/decay.ts) | 3.60 yr (extrapolated 525→500 km) | No independent external reference — internal cross-check only | Internal King-Hele / Kennewell integration (SQ-R-001 §4.1) | Cross-check only |
| 437 MHz slant range & free-space path loss at 525 km, 10° elevation (lib/physics/link-budget.ts) | 1,755.9 km / 150.15 dB | 1755.1 km / 150.16 dB | ITU-R P.525-4 free-space attenuation & spherical Earth geometry | Δ = 0.01 dB (Validated) |
| Required Eb/N₀ at BER = 10⁻⁵: coherent BPSK vs. non-coherent BFSK (lib/physics/link-budget.ts) | BPSK 9.59 dB / NC-BFSK 13.35 dB (Δ = 3.76 dB) | 9.59 dB / 13.35 dB (Δ = 3.76 dB) | Proakis & Salehi (2008), Digital Communications, 5th ed., §4.2 | Δ < 0.05 dB (Validated) |
| LoRa SF10 / 125 kHz (CR 4/5, NF = 6 dB) sensitivity & Time-on-Air for 20 B / 32 B (lib/physics/lora.ts) | −132.0 dBm · 20 B: 370.7 ms · 32 B: 452.6 ms | −132.0 dBm · 20 B: 370.7 ms · 32 B: 452.6 ms | Semtech SX1276/77/78/79 Datasheet Rev. 7 Table 13 & AN1200.13 §4 | Δ = 0.03 dB / 0.0% ToA (Validated) |
| 1P PocketQube (250 g, A = 150 cm², ε = 0.80) radiative thermal time constant τ (lib/physics/thermal.ts) | 56.5 min (orbit-avg solar power at β=15°: 540 mW) | 56.5 min (τ = m·c / 4εσAT₀³ at T₀ = 290 K, c = 900 J/kg·K) | Gilmore (2002), Spacecraft Thermal Control Handbook, Vol. 1; SQ-R-001 Table 3 | 0.01% (Validated) |
| 1P Al 7075-T6 simply supported backplate (50 × 50 × 1.6 mm, 38 g board mass) f₁ (lib/physics/structures.ts) | 1,997 Hz (PASS (> 200 Hz)) | 1997 Hz analytical SSSS plate (λ₁ = 2π² = 19.74; >200 Hz stiffness floor) | Leissa (1969), Vibration of Plates, NASA SP-160, §2.1 & AlbaPod ICD | 0.01% (Validated) |
PHASE 3A · FLIGHT RE-ENTRY EPOCH VS. ANALYTICAL DRAG INTEGRATOR
In-Orbit Flight Heritage Overlay (Grizu-263A & Delfi-PQ)
Comparison of nadir lab.’s numerical King-Hele drag integrator (simulateDecay in lib/physics/decay.ts) driven by NOAA SWPC observed monthly F10.7 for a priori nominal (B = 0.039 m²/kg) and effective (B_eff ≈ 0.050 m²/kg) ballistic parameters against the observed re-entry epoch (CelesTrak SATCAT 2 Oct 2023 / SatNOGS DB 3 Oct 2023, Day 628) and the constant F10.7 = 100 sfu pre-launch forecast.
- Effective B_eff ≈ 0.050 m²/kg (matches Day 628 re-entry)
- A priori nominal B = 0.039 m²/kg (774 days)
- Pre-Launch Forecast (Fixed F10.7 = 100 sfu, Ap = 12, 3.4 yr)
- Co-Manifested 1U CubeSat (1.33 kg, B = 0.0248 m²/kg)
Show the data as a table
| Mission elapsed time (days since 13 Jan 2022) | Effective B_eff ≈ 0.050 m²/kg (matches Day 628 re-entry) | A priori nominal B = 0.039 m²/kg (774 days) | Pre-Launch Forecast (Fixed F10.7 = 100 sfu, Ap = 12, 3.4 yr) | Co-Manifested 1U CubeSat (1.33 kg, B = 0.0248 m²/kg) |
|---|---|---|---|---|
| 0 | 525 | 525 | 525 | 525 |
| 150 | 515 | 518 | 519 | 520 |
| 300 | 502 | 508 | 512 | 515 |
| 450 | 469 | 487 | 503 | 504 |
| 628 | — | 444 | 491 | 487 |
| 774 | — | 202 | 479 | 469 |
| 850 | — | — | — | — |
PHASE 3B · BASEBAND AUDIO & WATERFALL SYNTHESIZER
Interactive SmallSat Signal Museum (CW, 2-FSK, GMSK & LoRa CSS)
Synthesize real baseband waveforms in your browser via Web Audio API, inspect their time-frequency spectrogram, and export 16-bit PCM .WAV reference files.
Linear frequency-modulated up-chirps and sync down-chirps across band; closes links from LEO with omnidirectional ground antennas.
- Occupied BW
- 125 kHz
- Demod Threshold
- SNR -15.0 dB