fusion (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#

Joint Kalman sensor-fusion PNT over the same hybrid inputs.

One run of scenarios/fusion-pnt.toml summarises as: scenario c8eac911bbe0 | fused | quantum PNT-holdover 6600s (t 6600s/p 6600s) integrity 1.000 security n/a (no attack) | classical PNT-holdover 1330s (t 1330s/p 6600s) integrity 0.973 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: coupled

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

Run it#

kshana scenarios/fusion-pnt.toml

2 bundled scenarios use this kind; the others are in scenarios/.

What it gives#

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

Evidence#

MODELLED 4 · VALIDATED 4: the verification matrix rows that name this kind.

• VALIDATED Recover an epoch state [r,v] from ground-station ranges via a Gauss–Newton batch differential corrector and a sequential filter, over a two-body+J2 force model Tests: batch_sequential_orbit_determination_reference.rs.
• MODELLED Error-state EKF over 15 INS states, a two-state receiver clock and one float carrier ambiguity per tracked satellite; pseudorange, carrier phase and optional range rate from an SGP4 Walker constellation (light-time and Sagnac), Klobuchar an Tests: fusion_carrier_tc.rs.
• MODELLED Three gnss-ins scenarios on the trajectory library (a vessel weaving at 8 m/s with a five-minute outage; a train through a two-satellite cutting and a tunnel; an aircraft whose outage covers a 25-degree banked turn) and the pack's optional Tests: gnss_ins_packs.rs.
• 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.
• and 4 more in the matrix.

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 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.
• MODELLED Composed bias + scale-factor + VRW + stability-decay position budget over holdover. Oracle (ReferenceImpl): Independent numpy Monte-Carlo SDE integration of double-integrated white-acceleration noise (validates the analytic VRW variance by a genuinely independent algorithm) + a Groves 2013 published-value anchor for the bias/scale-factor terms; the CAI device numbers quantify partner hardware and stay MODELLED

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))
• 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: LEO-PNT-FUSION.md