hybrid (scenario kind)

Scenario kind of the engine v0.38.0, family Inertial, fusion and quantum sensors. Advisory: analysis output from a research and engineering tool, not type-approved navigation equipment and not a safety-of-life service. Every label here is the engine's or the verification matrix's; a kind is MODELLED unless the matrix says otherwise (how a label is earned: the README's Evidence section).

What it does#

Hybrid PNT capstone: clock + IMU + time-transfer aiding.

One run of scenarios/hybrid-pnt.toml summarises as: scenario f33d734ecc51 | quantum PNT-holdover 6600s (t 6600s/p 6600s) integrity 0.998 security n/a (no attack) | classical PNT-holdover 350s (t 6600s/p 350s) integrity 1.000 security n/a (no attack)

Inputs#

From the schema (kshana kinds --json):

• Required fields: seed, timing_spec_ns, position_spec_m, time, gnss, resync, clock_quantum, clock_classical, accel_quantum, accel_classical
• Optional fields: none

The example scenarios/hybrid-pnt.toml sets, among others:

Run it#

kshana scenarios/hybrid-pnt.toml

What it gives#

The scalar results of that run, with the units the engine states:

Evidence#

MODELLED: the verification matrix rows that name this kind.

• MODELLED One stacked Kalman filter over position, velocity, clock phase and frequency fed pseudoranges that couple position and clock (Joseph-form updates carrying the cross-covariance); a 1-DOF variant augmented with a constant accelerometer-bias s Tests: fusion_coupled_filters.rs.

The rows the run itself exercised, with the oracle the matrix gives each (the public sources are named there):

• VALIDATED Allan/modified/Hadamard deviation + power-law noise ID with χ² CIs. Oracle (ExternalDataset): NIST SP 1065 (Riley) / Stable32 reference deviations on NBS14
• MODELLED Closed-form coast-error growth + holdover-to-threshold; quantum-clock classes. Oracle (ReferenceImpl): Multi-step clock_state covariance recursion (same-codebase cross-check); the underlying coast-variance & holdover-inversion kernel is externally validated vs scipy (see 'Clock-holdover coast-variance & threshold inversion'). The per-class red-noise-floor holdover figures stay MODELLED
• MODELLED 3-state (phase/freq/drift) van-Loan Kalman clock, Joseph-stabilised. Oracle (ReferenceImpl): filterpy 1.4.5 KalmanFilter (R. Labbe, MIT), with F via scipy.linalg.expm and Q via the Van-Loan 1978 block-matrix — an independent reference implementation reproducing kshana's full filter trajectory. Cross-implementation consistency: the clock physics / Allan calibration are not externally validated, so this stays MODELLED. 0.30 external comparison, a finding (stays MODELLED): on IGS final 30 s clocks of 11 GPS Blo
• MODELLED Two-way/TWSTFT (Sagnac), GNSS common-view, PPP; link-jitter→range. Oracle (ExternalDataset): Sagnac magnitude checked against an authoritative PUBLISHED VALUE — N. Ashby, 'Relativity in the GPS', Living Reviews in Relativity 6:1 (2003), Eq. 1.29: an eastward equatorial circumnavigation accrues 207.4 ns (2ωA_E/c²); kshana reproduces 207.386 ns. Independently corroborated by RTKLIB 2.4.3 geodist() (Takasu, BSD-2-Clause), which carries the same 2Aω/c² geometry. The composite BIPM TWSTFT transponder/common-view/
• MODELLED Cold-atom interferometer accelerometer from first principles (k_eff·T², QPN). Oracle (ExternalDataset): Published CAI primary-paper numeric vectors (Cheinet 2008 transfer function; Peters/Freier sensitivity): k_eff·T² matched exactly, shot-noise ASD a one-sided floor within ~2× of each published instrument (real devices carry technical noise above the quantum floor). A bracket, not parity. 0.30 round 2 (pre-registered fcb9ac64), a finding (stays MODELLED): the QPN-only rotation noise against the measured Gauguet et al.

Limitations#

What the run's own report says is not modelled or not validated:

• GNSS-denied clock holdover is MODELLED, not validated: checked against a separate implementation in this same codebase — independent of the unit under test, but not externally authoritative. (verification matrix (docs/MODELLED-RATIONALE.md))
• Onboard clock state estimation is MODELLED, not validated: checked against a separate implementation in this same codebase — independent of the unit under test, but not externally authoritative. (verification matrix (docs/MODELLED-RATIONALE.md))
• Time-transfer error budgeting is MODELLED, not validated: a sub-claim is externally checked, but the whole capability composes modelled pieces, so the capability stays Modelled. (verification matrix (docs/MODELLED-RATIONALE.md))
• Quantum inertial sensor performance is MODELLED, not validated: a sub-claim is externally checked, but the whole capability composes modelled pieces, so the capability stays Modelled. (verification matrix (docs/MODELLED-RATIONALE.md))
• Quantum inertial dead-reckoning resilience is MODELLED, not validated: checked against a separate implementation in this same codebase — independent of the unit under test, but not externally authoritative. (verification matrix (docs/MODELLED-RATIONALE.md))
• Spoofing detection is MODELLED, not validated: a sub-claim is externally checked, but the whole capability composes modelled pieces, so the capability stays Modelled. (verification matrix (docs/MODELLED-RATIONALE.md))
• Reproducibility & software assurance is MODELLED, not validated: a sub-claim is externally checked, but the whole capability composes modelled pieces, so the capability stays Modelled. (verification matrix (docs/MODELLED-RATIONALE.md))

See also#

• Family page: Inertial, fusion and quantum sensors
• All kinds: KINDS.md
• Topic page: INTEGRITY.md
• Topic page: MACHINE-INPUTS.md