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Results

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Observations only. Interpretation belongs in the thesis chapter and in limitations; mixing them here is how a result becomes hard to reuse.

All figures are from the primary element set (10,734 elements, median epoch 2026-08-29 21:17:42 UTC, seed 20271002) unless stated otherwise.

Headline numbers

QuantityValueUncertaintySource run
Worst horizontal displacement under single-beam spoofing1.51×10101.51 \times 10^{-10} mWorst case over 384 attempts, not a meanE3
Largest uniform offset applied while achieving that22.6 km of rangeE3
Position resolution δ\delta at στ=10\sigma_\tau = 10 ns3.1 mEmpirical RMS 3.1 m against CRLB 3.1 mE2
Estimator efficiency0.97 to 1.02Ratio of empirical RMS to CRLB across four decades of στ\sigma_\tauE2
Satellites visible above 25°68 medianRange 56 to 82 over 96 epochsE1
HDOP, six angularly diverse links1.02 medianRange 1.00 to 1.12E1
HDOP, six highest-elevation links2.73 medianRange 1.74 to 6.01E1
Relay detection, M5M \geq 5 at q=2q = 2100%Over 12 sampled epochsE4
Relay detection, M=3M = 3 at q=2q = 267%Over 12 sampled epochsE4
False positives at 10 ns, up to 1000 terminals/km²0%300-terminal honest populationE5
False positives at 100 ns, 100 terminals/km²28.3%300-terminal honest populationE5

Resolution against the analytic bound

στ\sigma_\tauCRLB δ\deltaEmpirical RMSRatio
1 ns0.31 m0.30 m0.97
10 ns3.1 m3.1 m1.00
100 ns30.9 m31.4 m1.02
1 μs308.6 m302.7 m0.98

False positives against legitimate density

στ\sigma_\tauδ\delta1/km²10/km²100/km²1000/km²
10 ns3.0 m0%0%0%0%
100 ns30.1 m0%0%28.3%99.3%
1 μs301 m25.7%99.7%100%100%

Across ground sites

SiteLatitudeVisibleHDOPδ\delta at 10 nsFP at 100/km²
Singapore1.4°N341.043.1 m0%
Washington DC38.9°N701.023.1 m0%
Grand Forks47.9°N711.023.0 m0%
Tromsø69.7°N201.103.3 m0%
Sydney33.9°S671.013.0 m0%

Degradation without simultaneous observation

Measured as Δmax=cs/ωLOS\Delta_{\max} = c\,s / \omega_{\mathrm{LOS}}, the displacement an adversary can fabricate before a constrained clock model rejects it.

Assumed oscillatorStability90° pass30° pass
Rubidium / GPSDO101010^{-10}2.3 m4.1 m
OCXO10810^{-8}228 m411 m
TCXO10610^{-6}22.8 km41.1 km
Uncompensated XO10510^{-5}228 km411 km

Figures

Registered under artifacts and referenced by identifier. Identifiers are provisional; these are not yet promoted out of the project working directory.

IDCaptionProduced by
FIG-001 (provisional)Relay detection rate versus relay size at στ=10\sigma_\tau = 10 ns, for quota 1, 2 and 5E4, via pgfplots reading eval-relay.csv at compile time

Tables

IDCaptionProduced by
TABLE-001 (provisional)Empirical resolution against the Cramér–Rao boundE2
TABLE-002 (provisional)False-positive rate versus legitimate terminal densityE5
TABLE-003 (provisional)Geometry across five ground sitesE8

Against the hypotheses

HypothesisPredictionObservedStanding
HYP-001Estimator attains δ=cστHDOP\delta = c\,\sigma_\tau\cdot\mathrm{HDOP}Ratio 0.97 to 1.02 across four decadessupported
HYP-002Uniform offset produces zero horizontal displacementWorst case 1.51×10101.51\times10^{-10} m over 384 attempts spanning a full orbital periodsupported
HYP-003Relay of MM identities detected once MM exceeds quotaTotal from M=5M=5 at q=2q=2; 67% at M=3M=3supported above a floor at Mq+3M \approx q+3

Unexpected observations

Things that were not predicted and are not fully explained. Recording them is how the next research question gets found.

  • Link selection dominates measurement precision. Choosing six satellites for angular diversity rather than elevation improves median HDOP by 2.7×, from 2.73 to 1.02, and collapses its spread from 1.74–6.01 to 1.00–1.12. This was not a hypothesis; it was found while checking whether the obvious selection rule was sensible. It costs nothing, since it changes which links to measure rather than how many.

  • The result is latitude-invariant even where the constellation is sparse. Visible count varies more than 3× across the five sites, from 20 at Tromsø to 71 at Grand Forks, yet HDOP stays within 1.01 to 1.10 and δ\delta within 3.0 to 3.3 m. Six well-separated links appear to be sufficient, and even the sparsest site offers six. Why the tail is this flat is not established.

  • The naive selection degrades further on independent data. On the cross-check element set the top-elevation HDOP tail reaches 8.90 against 6.01 on the primary set, while the diverse selection is unchanged at 1.02 median. The bad rule is not merely worse but less stable across datasets.

  • Small relays sit at a detection floor that was not predicted. At M=3,q=2M = 3, q = 2 detection is 67%, not near-total. The floor appears to be where relay size approaches the quota and density estimation loses its signal, but the boundary has not been characterised.

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