kshana 0.25.0

Open, reproducible PNT-resilience simulator with quantum-sensor performance models
Documentation 
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# ============================================================================
# TEACHING COPY — Tutorial 2: Clock holdover. Kind = clock.
#
# Provenance: a comment-annotated copy of scenarios/clock-holdover.toml. The
# FIELD VALUES are byte-for-byte identical to the parent, so the documented
# output (and the golden hashes in tests/golden/) are unaffected — a comment
# never changes a scenario hash (the hash is over the parsed definition: seed,
# thresholds, params, GNSS windows; not the file bytes).
#
# What it does: 2 h timeline — 10 min GNSS sync, then ~1.8 h denied — against a
# 20 ns timing spec. Compares an optical clock vs a chip-scale atomic clock
# (CSAC) coasting through the outage.
#
# Oracle (non-circular): the white-FM phase-error growth law sigma_x(T) = sqrt(q_wf*T),
# q_wf = sigma_y(1s)^2 (NIST SP 1065, the same relation tests/calibration.rs
# validates the ADEV against to ~2%). CSAC q_wf=9e-20 -> 1-sigma 20 ns crossing
# at ~4444 s; the engine's k-sigma/p95 spec-cross at ~2610 s sits in that band.
#
# expected: scenario 5ba83a232b94 | quantum holdover 6600s p95 0.0ns integrity 1.000 security 0.997 | classical holdover 2610s p95 19.7ns integrity 1.000 security 0.000
# ============================================================================

# Empty/omitted kind defaults to the clock pack; the parent omits `kind`, so do we.
seed = 42              # fixes the noise realization -> bit-identical reruns
threshold_ns = 20.0    # operational timing spec; holdover = time in-spec after GNSS loss

[time]
step_s = 10.0          # grid resolution; holdover is quantised to this (a lower bound)
duration_s = 7200.0    # 2 h total run

[gnss]
# The availability timeline — the outage driver. 10 min nominal, then ~1.8 h denied.
windows = [
  { t0 = 0.0,    t1 = 600.0,  state = "nominal" },
  { t0 = 600.0,  t1 = 7200.0, state = "denied" },
]

[clock_quantum]
# Optical Sr lattice clock; sigma_y(1s)=1e-15 space goal (cited, not invented).
id = "optical-sr-lattice"
provenance = "Strontium optical lattice clock, space-oriented goal sigma_y(1s)=1e-15 (Origlia/Schiller/Bongs et al., arXiv:1503.08457); q_wf=sigma_y(1s)^2; ground-demonstrator maturity, not flown; flicker/aging not modeled"
y0   = 5.0e-17         # initial fractional-frequency offset
q_wf = 1.0e-30         # white FM:  q_wf = sigma_y(1s)^2 (units s^2)
q_rw = 0.0             # random-walk FM (off)

[clock_classical]
# Microchip SA.45s / SA65 CSAC; sigma_y(1s)=3e-10 (datasheet) — a deployed part.
id = "csac-sa45s"
provenance = "Microchip SA65 / SA.45s CSAC datasheet sigma_y(1s)=3e-10; q_wf=sigma_y(1s)^2; flicker/aging not modeled"
y0   = 5.0e-10
q_wf = 9.0e-20         # (3e-10)^2 — the term that drives the ~2610 s holdover
q_rw = 0.0