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

integrity (scenario kind)

Scenario kind of the engine v0.38.0, family GNSS measurements, positioning and integrity. 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#

Snapshot / solution-separation / ARAIM RAIM with HPL/VPL and a Stanford diagram.

One run of scenarios/integrity-raim.toml summarises as: integrity | 24 satellites | 344/361 epochs available (95.3%) | HAL 40 m VAL 50 m | sigma 1.0 m | Stanford(V): 0 integrity events, 0 HMI

Inputs#

From the schema (kshana kinds --json):

  • Required fields: mask_deg, sigma_uere_m, p_fa, p_md, al_h_m, al_v_m, time, user|user_site, constellation
  • Optional fields: sigma_ura_m, b_nom_m, constellations, seed, araim_dual, p_hmi, skyline

The example scenarios/integrity-raim.toml sets, among others:

Field Value Unit
al_h_m 40 m
al_v_m 50 m
constellation.altitude_km 20200 km
constellation.inclination_deg 55 deg
constellation.phasing_f 1 not stated
constellation.planes 6 not stated
constellation.sats_per_plane 4 not stated
kind integrity text
mask_deg 5 deg
p_fa 1.0000e-5 not stated
p_md 0.001 not stated
seed 7 not stated

Run it#

kshana scenarios/integrity-raim.toml

3 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
al_h_m 40 m
al_v_m 50 m
samples_available 344 count
samples_total 361 count
stanford.alert_limit_m 50 m
The chart the engine writes for scenarios/integrity-raim.toml, kind integrity

Evidence#

MODELLED 6 · VALIDATED 4: the verification matrix rows that name this kind.

  • MODELLED The optional [integrity] section of the clock kind (clock_integrity::run): from a stated site and constellation presets (geometry::sky_geometry), at every integrity epoch while the GNSS timeline is not denied, snapshot RAIM (raim::snapshot_ Tests: clock_integrity.rs.
  • VALIDATED Scalar-time solution-separation TPL over heterogeneous sources; PL driven by worst-exclusion subset noise + UTC(k) bias
  • MODELLED PL(τ)=max(TPL_handover,HPL(τ)); lower-semicontinuous PL(0+)≥PL(0−); K(IR/2) running-max; τ/τ³/τ⁵ phase exponents
  • VALIDATED Running-max envelope overbound-covers (zero-piercing) a real metrological series at every tested lag tau>=90d on a disjoint segment; short-tau (<=30d) is a disclosed Modelled boundary Tests: cti_holdover_coverage_reference.rs.
  • and 6 more in the matrix.

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

  • VALIDATED ARAIM multiple-hypothesis solution separation per the ARAIM Airborne Design Document (ADD) v4.2 (araim_reference::add_v42_protection_levels and add_v42_protecti. Oracle (ExternalDataset): Three independent tools, pre-registered (0123cee1) before any fixture or oracle output existed, tolerances fixed then. (1) ARAIM: Stanford MAAST for ARAIM 2 (commit ab70e2a3, BSD-3) mhss_raim_baseline_v5.m, run as a separate program under GNU Octave 8.4 with a driver-side unique() compatibility shim (disclosed, no algorithm change), at the ADD TOL_PL of 0.05 m: the Rust reproduces the ADD reference implementation on
  • VALIDATED GDOP/PDOP/HDOP/VDOP/TDOP from line-of-sight geometry via Q=(HᵀH)⁻¹ with a local ENU split. Oracle (ExternalDataset): gnss_lib_py 1.0.4 (Stanford NAV Lab) DOP — independent library, matched to 1e-6 relative
  • VALIDATED The distributional core every protection level rests on: the snapshot fault-detection threshold χ²₁₋ₚfₐ(dof), the missed-detection non-centrality pbias=√λ, and . Oracle (ExternalDataset): SciPy 1.17.0 (scipy.stats.chi2/.norm/.ncx2 + optimize.brentq) — independent library (Cephes/Boost), a different algorithm from Kshana's incomplete-gamma series; matched to ≤1e-6 rel. Kernel only. The ARAIM MHSS P_HMI budget allocation is no longer without a published numeric oracle — the WG-C ARAIM Technical Subgroup's own worked example now backs the separate 'ARAIM MHSS protection levels against published referen
  • 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

Limitations#

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

  • 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#