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ProjectsPRJ-001Experiments

Experiments

Active

Full records live under experiments. This page is the project’s index into them. All eight sub-experiments run from a single harness, ephemeris/examples/evaluate.rs, and complete in about two seconds once built.

Configuration common to all runs

ParameterValue
Element set10,734 Starlink elements, CelesTrak supplemental GP, median epoch 2026-08-29 21:17:42 UTC
PropagatorSGP4, TEME → ECEF → ENU
Observer38.9°N, 77.0°W (Washington DC)
Elevation mask25°
Epochs96 at one-minute spacing, spanning a full orbital period
Link budget6, selected for angular diversity
Seed20271002

Runs

ExperimentTestsStatusResultReported in
E1 Visibility and dilution of precisionInstrument characterisationcomplete56 to 82 visible, median 68; HDOP median 1.02 on six diverse linksCH05, PUB-001 §VI-A
E2 Resolution vs Cramér–Rao boundHYP-001completeRatio 0.97 to 1.02 across three decadesPUB-001 Table III
E3 Spoofing immunity across epochsHYP-002complete384 attempts, worst displacement 1.51×10101.51\times10^{-10} mPUB-001 §VI-D
E4 Relay detection vs size and quotaHYP-003completeTotal from M=5M=5 at q=2q=2; 67% at M=3M=3PUB-001 Figure 1
E5 False positives vs terminal densityOperating envelopecompleteClean at 10 ns to 1000/km²; 28.3% at 100 ns and 100/km²PUB-001 Table IV
E6 Degradation without Condition SBoundary of HYP-002completeOCXO 228–411 m; TCXO 22.8–41.1 kmPUB-001 §IV-A
E7 Terminals required by residual adversaryEconomic bound on A4completeM/q\lceil M/q \rceil; 500 terminals for 10310^3 identities at q=2q=2PUB-001 §VI-H
E8 Robustness across ground sitesExternal validitycompleteFive sites, 1.4°N to 69.7°N; HDOP 1.01 to 1.10PUB-001 Table V

Cross-set replication

The entire evaluation was repeated on an independently derived element set: CelesTrak’s own general-perturbations solution, 10,731 elements at a median epoch nine hours later, produced by a different orbit-determination pipeline.

MetricSupplementalGP
Visible, median6872
HDOP, six diverse1.021.02
δ\delta at 10 ns3.1 m3.1 m
Estimator / CRLB0.97–1.020.94–1.02
Worst spoof displacement1.51×10101.51\times10^{-10} m1.71×10101.71\times10^{-10} m
Relay M=5M=5, q=2q=2100%100%
False positives, 10 ns, 1000/km²0%0%

Every headline figure reproduced. One difference is worth recording: the top-elevation HDOP tail is worse on the GP set, 8.90 against 6.01, which strengthens the case for diverse link selection rather than weakening it.

Planned but not run

ExperimentPurposeWhy not run
Doppler-augmented estimationTest whether folding Doppler in tightens δ\deltaEstimator is delay-only. Doppler is modelled in the code but not wired into the solve. Highest-value remaining run, since δ\delta binds the false-positive envelope
Multi-beam adversary detectionTest whether independently timed beams leave an aperture-level signatureRequires a phased-array transmit model the project does not have
Mobile terminalsTest whether the bound survives maritime and aeronautical motionScoped out; fixed terminals assumed throughout
Second epoch of the supplemental setCross-epoch replication within one pipelineCelesTrak’s supplemental set is operator-uploaded and was unchanged over a 14-hour window. Substituted the GP set, which varies both epoch and pipeline and is the stronger check

Run and excluded

A run that happened but is not reported is listed here with the reason. Silently dropping runs is the difference between a result and a selected result.

ExperimentReason for exclusion
Full evaluation on the Walker-delta constellationSuperseded. Run while CelesTrak was unreachable, using a synthetic 1,584-satellite single shell. Every qualitative conclusion matched, but the single-shell model shows only 9 to 14 satellites against 56 to 82 for the real multi-shell constellation, so its resolution figures are not comparable. The code is retained as a dependency-free fallback
Detector runs using fixed-grid quantisationInstrument was flawed, not the run. The grid fragmented relay clusters, placing 45 of 200 identities in the modal cell. Replaced with density-based detection and re-run; see methodology
Adversary classes A1 (emulator) and A2 (replayer)Not implemented rather than excluded. An adversary holding no terminal has no physical layer into which to inject observables, so simulating one would model a capability it does not have
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