Scenario kind pagesEdit on GitHubSource: docs/kinds/by-kind/inertial.md

inertial (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#

1-DOF inertial dead-reckoning during a GNSS outage.

One run of scenarios/imu-deadreckoning.toml summarises as: scenario fc9191cef784 | quantum holdover 6600s p95 41.39m | classical holdover 350s p95 30629.9m

Inputs#

From the schema (kshana kinds --json):

  • Required fields: seed, threshold_m, time, gnss, accel_quantum, accel_classical
  • Optional fields: runs

The example scenarios/imu-deadreckoning.toml sets, among others:

Field Value Unit
accel_classical.bias 0.00157 m/s^2
accel_classical.bias_instability 1.0000e-5 not stated
accel_classical.id nav-grade-quartz text
accel_classical.provenance Navigation-grade quartz accelerometer (Honeywell QA-2000 / G text
accel_classical.q_aa 1.0000e-13 (m/s^2)^2/s
accel_classical.q_va 3.8416e-8 (m/s^2)^2/Hz
accel_quantum.bias 5.8800e-7 m/s^2
accel_quantum.id cold-atom-quat text
accel_quantum.provenance Exail hybrid quantum accelerometer triad: bias stability 6e- text
accel_quantum.q_va 4.6656e-8 (m/s^2)^2/Hz
gnss.windows[0].state nominal text
gnss.windows[0].t0 0 not stated

Run it#

kshana scenarios/imu-deadreckoning.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:

Result Value Unit
classical.fom.availability 0.131761 1
classical.fom.drift_slope_m_per_s 5.138079 m/s
classical.fom.holdover_s 350 s
classical.fom.integrity no value not stated
classical.fom.pos_p95_m 30629.852742 m
classical.fom.pos_rms_m 15189.151543 m
classical.fom.security no value not stated
classical.monte_carlo false flag
classical.spec.id nav-grade-quartz text
classical.spec.kind inertial text
The chart the engine writes for scenarios/imu-deadreckoning.toml, kind inertial

Evidence#

MODELLED 6 · VALIDATED 2: the verification matrix rows that name this kind.

  • VALIDATED Quaternion-attitude, WGS-84 NED strapdown inertial mechanization (coning/sculling-compensated) propagating a navigation state from (Δθ, Δv) increments Tests: classical_strapdown_ins_reference.rs.
  • MODELLED Cold-atom interferometer accelerometer from first principles (k_eff·T², QPN) Tests: quantum_inertial_sensor_reference.rs.
  • MODELLED Mach–Zehnder fringe-ambiguity dynamic range: the 2π-periodic fringe readout sets a maximum unambiguous specific force a_max=π/(k_eff·T²), and the unambiguous range in resolution cells a_max/σ_a=π/σ_Φ is independent of the optical scale fact
  • MODELLED Composed bias + scale-factor + VRW + stability-decay position budget over holdover Tests: quantum_inertial_dead_reckoning_reference.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):

  • 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
  • MODELLED Deterministic, scenario-hashed, SBOM + cross-platform golden gates. Oracle (ExternalDataset): SBOM conformance to the official CycloneDX 1.5 JSON Schema (+ valid SPDX identifiers) — an external published standard, zero validation errors over the full dependency graph; the FoM-determinism / byte-reproducibility part remains a pinned self-consistency check, so the row stays MODELLED
  • PARTNER Not provided — performance models only; cold-atom/clock hardware is a partner's. Oracle (NoneKind): none: a partner-owned discipline, with no module and no test by design

Limitations#

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

  • 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))
  • 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#