Results
ActiveObservations 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
| Quantity | Value | Uncertainty | Source run |
|---|---|---|---|
| Worst horizontal displacement under single-beam spoofing | m | Worst case over 384 attempts, not a mean | E3 |
| Largest uniform offset applied while achieving that | 22.6 km of range | — | E3 |
| Position resolution at ns | 3.1 m | Empirical RMS 3.1 m against CRLB 3.1 m | E2 |
| Estimator efficiency | 0.97 to 1.02 | Ratio of empirical RMS to CRLB across four decades of | E2 |
| Satellites visible above 25° | 68 median | Range 56 to 82 over 96 epochs | E1 |
| HDOP, six angularly diverse links | 1.02 median | Range 1.00 to 1.12 | E1 |
| HDOP, six highest-elevation links | 2.73 median | Range 1.74 to 6.01 | E1 |
| Relay detection, at | 100% | Over 12 sampled epochs | E4 |
| Relay detection, at | 67% | Over 12 sampled epochs | E4 |
| False positives at 10 ns, up to 1000 terminals/km² | 0% | 300-terminal honest population | E5 |
| False positives at 100 ns, 100 terminals/km² | 28.3% | 300-terminal honest population | E5 |
Resolution against the analytic bound
| CRLB | Empirical RMS | Ratio | |
|---|---|---|---|
| 1 ns | 0.31 m | 0.30 m | 0.97 |
| 10 ns | 3.1 m | 3.1 m | 1.00 |
| 100 ns | 30.9 m | 31.4 m | 1.02 |
| 1 μs | 308.6 m | 302.7 m | 0.98 |
False positives against legitimate density
| 1/km² | 10/km² | 100/km² | 1000/km² | ||
|---|---|---|---|---|---|
| 10 ns | 3.0 m | 0% | 0% | 0% | 0% |
| 100 ns | 30.1 m | 0% | 0% | 28.3% | 99.3% |
| 1 μs | 301 m | 25.7% | 99.7% | 100% | 100% |
Across ground sites
| Site | Latitude | Visible | HDOP | at 10 ns | FP at 100/km² |
|---|---|---|---|---|---|
| Singapore | 1.4°N | 34 | 1.04 | 3.1 m | 0% |
| Washington DC | 38.9°N | 70 | 1.02 | 3.1 m | 0% |
| Grand Forks | 47.9°N | 71 | 1.02 | 3.0 m | 0% |
| Tromsø | 69.7°N | 20 | 1.10 | 3.3 m | 0% |
| Sydney | 33.9°S | 67 | 1.01 | 3.0 m | 0% |
Degradation without simultaneous observation
Measured as , the displacement an adversary can fabricate before a constrained clock model rejects it.
| Assumed oscillator | Stability | 90° pass | 30° pass |
|---|---|---|---|
| Rubidium / GPSDO | 2.3 m | 4.1 m | |
| OCXO | 228 m | 411 m | |
| TCXO | 22.8 km | 41.1 km | |
| Uncompensated XO | 228 km | 411 km |
Figures
Registered under artifacts and referenced by identifier. Identifiers are provisional; these are not yet promoted out of the project working directory.
| ID | Caption | Produced by |
|---|---|---|
| FIG-001 (provisional) | Relay detection rate versus relay size at ns, for quota 1, 2 and 5 | E4, via pgfplots reading eval-relay.csv at compile time |
Tables
| ID | Caption | Produced by |
|---|---|---|
| TABLE-001 (provisional) | Empirical resolution against the Cramér–Rao bound | E2 |
| TABLE-002 (provisional) | False-positive rate versus legitimate terminal density | E5 |
| TABLE-003 (provisional) | Geometry across five ground sites | E8 |
Against the hypotheses
| Hypothesis | Prediction | Observed | Standing |
|---|---|---|---|
| HYP-001 | Estimator attains | Ratio 0.97 to 1.02 across four decades | supported |
| HYP-002 | Uniform offset produces zero horizontal displacement | Worst case m over 384 attempts spanning a full orbital period | supported |
| HYP-003 | Relay of identities detected once exceeds quota | Total from at ; 67% at | supported above a floor at |
Unexpected observations
Things that were not predicted and are not fully explained. Recording them is how the next research question gets found.
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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.
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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 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.
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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.
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Small relays sit at a detection floor that was not predicted. At 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.