hybrid-optical-rf (scenario kind)

Scenario kind of the engine v0.38.0, family Optical PNT. 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#

MODELLED heterogeneous optical + RF PNT joint figure of merit (P5): composes the 1550 nm two-way optical link budget (photon-limited two-way ranging CRLB σ_τ/√N and diffraction footprint λ/D·range), a cross-modality solution-separation RAIM protection level (position AND timing) that fuses the loose RF and tight optical solutions with disparate covariances, the N-station optical clear-sky availability (independent-union 1−Π(1−a_i) and a spatially-correlated variant), an optical↔RF state/covariance handoff with a PROVEN bit-continuous (no-jump) mean and a NEES χ² consistency gate, and a joint P(available AND precision-grade AND integrity-assured) score with correlation handling. VALIDATED closed form: the ranging CRLB, diffraction footprint, χ² protection-level quantile, union combinatorics, handoff mean-continuity + NEES gate, and the joint independent product. MODELLED: the optical loss allocations, RF/optical σ magnitudes, cloud-climatology inputs, correlations, and P_HMI budget. Not a certified availability/integrity product.

One run of scenarios/hybrid-optical-rf.toml summarises as: hybrid-optical-rf | optical footprint 700 m, 1489 photons -> ranging σ 0.194 mm, timing σ 1.30 ps | cross-RAIM HPL 6.2 m / VPL 6.6 m / TPL 13.3 ns (protected) | availability 99.5% (5 sites) | handoff no-jump OK NEES 3.34∈[0.48,11.14] in-gate | joint FoM 0.993 (A 0.995 · P 0.995 · I 1.000) | Validated CRLB/χ²-PL/union/handoff, Modelled σ/climatology

Inputs#

From the schema (kshana kinds --json):

• Required fields: none
• Optional fields: wavelength_nm, tx_power_w, tx_aperture_m, rx_aperture_m, range_km, pulse_rms_ps, integration_s, atmospheric_loss_db, pointing_loss_db, optics_efficiency, detector_efficiency, two_way, rf_pos_sigma_m, rf_vertical_sigma_m, rf_clock_sigma_s, p_fa, p_md, alert_limit_h_m, alert_limit_v_m, alert_limit_t_s, grade_pos_m, grade_time_s, n_optical_sites, site_correlation, fom_correlation, handoff_inflation, p_hmi, fault_ramp_rate_pos_m_s, fault_ramp_rate_clock_s_s, process_noise_pos_psd_m2_s, process_noise_clock_psd_s2_s, coast_coverage_k, rf_band, rf_eirp_dbw, rf_g_over_t_db, rf_other_losses_db, rf_data_rate_bps, rf_required_eb_n0_db, rf_chip_rate_hz, rf_correlator_spacing_chips, rf_dll_bandwidth_hz, rf_tracking_threshold_dbhz, rf_degraded_margin_db

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

Run it#

kshana scenarios/hybrid-optical-rf.toml

What it gives#

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

Result label (the engine's): Heterogeneous optical + RF PNT joint availability / precision / integrity figure of merit (P5). VALIDATED closed form: the photon-limited ranging CRLB (σ_τ/√N) and diffraction footprint (λ/D·range), the χ² cross-modality protection-level quantile, the N-station independent-union availability (1 − Π(

Evidence#

No matrix row names this kind by name; the label on its result is the engine's own, above.

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

• 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
• MODELLED The hybrid-optical-rf report states the link configuration it actually ran at (carrier wavelength, transmit and receive aperture, range, pulse width, integratio. Oracle (InternalConsistency): No external oracle, and none is possible: this is self-description, not a measurement. It is recorded because the absence of it was a defect -- P5 had to quote the carrier wavelength and transmit aperture from source defaults, and to infer that a bare variance was in square metres from an internal consistency check. The inference was correct, which is precisely why it mattered: nothing would have caught it being wr
• MODELLED The hybrid-optical-rf report states an RF link availability, composed from quantities the engine already computes rather than from an imported climatology, and . Oracle (InternalConsistency): No external oracle, and ExternalDataset is declined. The two inputs are an Eb/N0 margin and a C/N0 threshold crossing, both functions of a MODELLED EIRP, figure of merit and lumped loss allocation; there is no measured availability record for an Earth-Moon optical/RF hybrid service to check the composed figure against. The checks that exist are internal and are stated as such: the composition is recomputed from the r
• MODELLED The hybrid-optical-rf report emits the optical-versus-RF ranging ratio with the ONE configuration both legs were evaluated at carried in the same object: the sa. Oracle (InternalConsistency): No external oracle for the RATIO, and ExternalDataset is declined deliberately. The underlying RF chain does have one -- tests/validate_p5_rf_ranging_precision.rs checks linkbudget::link_budget and navsignal::dll_code_jitter_chips against an independent Python/NumPy fixture and against the hardcoded Kaplan & Hegarty worked value (2.814e-3 chip / 0.825 m at 45 dB-Hz) -- and the optical CRLB has its own closed-form row
• MODELLED The hybrid-optical-rf report states what the cross-modality chi-square monitor can actually DETECT, not only that it passes a fault-free case: the minimum detec. Oracle (InternalConsistency): Two internal oracles, no external dataset. (1) Closed-form round trip: the minimum detectable bias is produced by inverting the non-central chi-square tail on the non-centrality (raim::pbias) and is verified by feeding the resulting non-centrality back through raim::noncentral_chi2_cdf at the monitor's own threshold, which must return P_md. (2) Injection vs analysis: a bias is written into the RF estimate of one axis

Limitations#

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

• Heterogeneous optical + RF PNT joint availability / precision / integrity figure of merit (P5). VALIDATED closed form: the photon-limited ranging CRLB (σ_τ/√N) and diffraction footprint (λ/D·range), the χ² cross-modality protection-level quantile, the N-station independent-union availability (1 − Π(1−a_i)), the optical↔RF handoff mean-continuity (bit-for-bit no-jump) invariant and NEES χ² gate, and the joint-FoM inde (result label)
• MODELLED heterogeneous optical + RF PNT joint figure of merit (P5): composes the 1550 nm two-way optical link budget (photon-limited two-way ranging CRLB σ_τ/√N and diffraction footprint λ/D·range), a cross-modality solution-separation RAIM protection level (position AND timing) that fuses the loose RF and tight optical solutions with disparate covariances, the N-station optical clear-sky availability (independent-un (kind catalogue (kshana kinds --json))
• MODELLED: the optical loss allocations, RF/optical σ magnitudes, cloud-climatology inputs, correlations, and P_HMI budget. (kind catalogue (kshana kinds --json))
• MODELLED. Validated closed forms: ranging CRLB (sigma_tau/sqrt(N)), diffraction footprint (lambda/D * range), chi-square protection-level quantile, union combinatorics, handoff mean-continuity + NEES gate, and the joint independent product. The loss allocations, sigma magnitudes, cloud-climatology inputs, correlations and P_HMI budget are Modelled representative inputs. Every field below is optional and shown at its (scenario file comment, lines 10 to 14)
• --- G15 bias / ramp fault injection against the cross-modality monitor --- The minimum detectable bias and the detection-power curve are ANALYTIC (non-central chi-square inversion), so they need no inputs of their own. These two only set the ramp rate the reported time-to-detect is a rate conversion of. Both MODELLED. (scenario file comment, lines 56 to 59)
• --- G17 post-handover coast: process noise and the alert-limit crossing --- Random walk on the existing 4-state (east, north, up, clock) handoff filter. The alert limits are the ones already declared above; only the process noise and the coverage factor are new. Both PSDs are MODELLED representative inputs and the crossing times scale directly with them. (scenario file comment, lines 63 to 67)
• 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))
• Hybrid optical/RF report self-description is MODELLED, not validated: checked against its own closed-form / analytic identity — catches transcription and coefficient errors, but is not an external oracle. (verification matrix (docs/MODELLED-RATIONALE.md))

See also#

• Family page: Optical PNT
• All kinds: KINDS.md