Crate kshana 

kshana — a validated, reproducible PNT simulation substrate

kshana is an open-source engine for positioning, navigation and timing (PNT) analysis: GNSS geometry and integrity, clock holdover and time transfer, inertial and alt-PNT navigation, orbit and mission analysis, lunar/cislunar PNT, and RF resilience. It has no scientific runtime dependencies, and every run is deterministic from its inputs.

Entry points

• api::run_toml is the single dispatch entry: it parses a scenario TOML, detects its kind, runs it, and returns a structured result. Every language binding — the Python package, the MCP server, and the WASM playground — is a thin wrapper over it, so all surfaces run the identical engine.
• api::list_scenario_kinds is the machine-readable catalogue of the built-in scenario kinds, each with its description and required/optional fields — the same catalogue the docs/SCENARIOS.md reference is generated from.

Honesty model

Every capability carries an explicit maturity tier, generated from source in verification::verification_matrix (the single source of truth) and CI-pinned so the labels cannot drift from the code:

• Validated — checked against an independent external oracle (a published dataset, reference vectors, or a closed-form value). A self-consistency check can never be labelled Validated.
• Modelled — implemented from published or first-principles physics with tests, but not checked against an external oracle to a stated tolerance.
• PartnerOwned — a capability kshana deliberately does not provide, recorded as a gap rather than faked.

The per-figure-of-merit tier shown next to a result is derived from this same matrix via fom_label. kshana makes no technology-readiness or heritage claim and is not affiliated with, nor endorsed by, any space agency.

Reproducibility

Runs are deterministic: a scenario, a seed, and a pinned engine version rebuild the same figures byte-for-byte. The governing equations behind the physics are collected, with their literature sources, in the docs/EQUATIONS.md reference.

Modules

acquisition

GNSS signal acquisition: square-law (non-coherent) detector statistics and the generalized Marcum Q-function.

allan

Allan-family frequency-stability estimators — overlapping ADEV, MDEV, TDEV and HDEV, and the IEEE-1139 power-law noise fit.

altpnt

Alternative-PNT (GPS-denied) navigation packs.

antenna

Orbital transmitter antenna pattern and surface capture footprint.

api

Scenario dispatch shared by the CLI and the language bindings.

assurance

Assurance primitives: provenance, uncertainty, and external-oracle attestation.

attack_surface

Lunar surface-navigation attack-surface scenario (P1): the binary-reachable (run_toml / CLI / Python / MCP) face that composes the open signal-security analyses into one run. kind = "lunar-attack-surface".

attitude_budget

3-DOF attitude & pointing error budget: a scalar, pre-hardware AOCS/GNC complement to high-fidelity tools (Basilisk, 42) — the environmental gravity-gradient disturbance torque and a root-sum-square pointing-error budget over the contributing error sources, producing a single pointing figure of merit a systems engineer brackets before committing to a control design.

attitude_dynamics

Torque-free rigid-body attitude dynamics: Euler’s rotational equations of motion coupled to quaternion attitude kinematics, integrated with a fixed-step RK4 propagator.

batch_ls

Gauss–Newton weighted batch least squares — the batch differential corrector.

body

Central-body parameters — the gravitational and orientation constants that turn the Earth-hard-coded dynamics core into a body-agnostic one.

bplane

Hyperbolic-flyby B-plane targeting and patched-conic gravity assist.

ccsds_tdm

CCSDS Tracking Data Message (TDM) parser and writer — the standard interchange format for raw radiometric tracking measurements.

chart

Shared SVG charting helpers used by the per-pack chart renderers.

cio

IAU 2006/2000A CIO-based celestial-to-terrestrial reduction (GCRS↔CIRS↔ITRS).

cislunar_observability

cislunar-observability scenario — planar cislunar constellation observability (P6).

cislunar_srif

Independent SRIF cross-validation of the cislunar observability transition (paper P6, L32).

clock_specs

Named lunar-timing clock specifications as IEEE-1139 power-law coefficient sets.

clock_state

Three-state onboard clock error model: phase, fractional-frequency, frequency drift.

conflict_resilience

conflict-resilience scenario — layered-PNT resilience in a contested / conflict environment (paper P7).

conflict_threat_params

Sourced threat-parameter provenance catalog for the conflict-resilience pack (L36).

cr3bp

Circular restricted three-body problem (CR3BP) for the Earth–Moon system.

cross_raim

Cross-modality RAIM / protection level — receiver-autonomous integrity for a heterogeneous pair of PNT solutions. Where crate::raim monitors many homogeneous RF pseudoranges of one constellation, this module treats an RF PVT/time solution and an optical PVT/time solution as two independent measurements of the same underlying geometry, with disparate covariances (RF loose — metres, nanoseconds; optical tight — centimetres, picoseconds), and monitors their consistency.

cross_sensor_integrity

Layer-2 cross-sensor integrity sizing: minimum detectable spoof walk.

crossover

Quantum-versus-classical resilience crossover study.

crpa

Controlled-reception-pattern antenna (CRPA) anti-jam beamforming: deterministic null-steering and minimum-variance distortionless-response (MVDR) weights for an N-element GNSS array.

cw_dynamics

Clohessy–Wiltshire / Hill relative-motion dynamics: the linearised motion of a chaser relative to a target on a circular reference orbit, expressed in the target’s local-vertical/local-horizontal (LVLH) frame.

deepspace_od

Numerically-robust sequential orbit determination — a hand-rolled Square-Root Information Filter (SRIF; Bierman 1977) with reduced-dynamic empirical accelerations, the factored complement to the batch differential corrector of crate::precise_od.

detection

Detection-theory primitives for the spoof monitor.

dro

Planar distant-retrograde-orbit (DRO) seeder for the Earth–Moon CR3BP (paper P6, L29).

egm2008_data

EGM2008 geopotential spherical-harmonic coefficients to degree/order 70 — AUTO-GENERATED from tools/egm2008_to70.gfc by tools/gen_egm2008.py; do not edit by hand. Fully normalized, tide-free. The EGM2008 model is an NGA public-domain product (via ICGEM). EGM2008_COEFFS are (n, m, Cnm, Snm).

ensemble

Monte Carlo ensembles for the clock-holdover scenario.

eo_payload

Earth-observation payload footprint & coverage geometry: the SMAD/Wertz “space triangle” relations that turn an orbit altitude and a sensor field of view into the angular radius of the Earth, the swath width, the nadir ground sample distance, the maximum off-nadir access, and the equatorial ground-track spacing that drives revisit.

eop

IERS Earth-orientation parameters from the official finals2000A product.

ephem

Built-in low-precision analytical ephemerides for the third-body perturbing bodies, so the numerical propagator’s third-body force (crate::forces::third_body_accel) needs no external DE/SPK kernel for a low-fidelity run.

ephem_provider

A pluggable ephemeris provider seam — the source of one body’s position relative to another in the inertial frame — abstracted so the fidelity of those positions can be swapped without touching the deep-space light-time correction (D0.7) or the interplanetary orbit determination (D2/D3) that will consume it.

ephemeris

Ephemeris & ground-track scenario — the user-facing surface for satellite VELOCITY, the full frame reductions, and the WGS-84 sub-satellite point.

estimator

Clock-holdover state estimators: the coasted time-error prediction a GNSS-denied clock free-runs on.

eval_stats

Hand-derived statistics for the impairment-evaluation study.

filter_health

Kalman filter-consistency health monitoring (NIS / NEES).

fim

Fisher information, the Cramér–Rao lower bound, and observability/datum-defect analysis — the information-geometry core for experiment design and rank diagnosis.

fom

Figures of merit — the scored timing, integrity and security metrics a scenario reports, and the samples that feed them.

fom_label

Per-figure-of-merit validation tier.

forces

Orbital force model: two-body gravity, the zonal-harmonic field, and third-body gravity.

frame_eop

Real-time frame / Earth-orientation prediction budget for lunar timing.

frames

Reference-frame reduction and a geodetic ground-station observer.

frugal

Frugal-engineering cost-per-coverage / ROI layer over constellation sizing.

fusion

Joint Kalman sensor-fusion estimator.

geolocation

Passive emitter geolocation by TDOA (time-difference-of-arrival) and FDOA (frequency-difference-of-arrival) across a network of receivers — the core of locating a jammer/spoofer, or reverse-PNT off an opportunistic emitter, when GNSS itself is the thing under attack.

glonass

GLONASS broadcast ephemeris: a PZ-90 state-vector model with RK4 propagation.

gnss_sim

Measurement-domain GNSS simulation: pseudoranges with ionospheric and tropospheric delays.

gravimeter

Cold-atom gravimeter measurement model and a spherical-harmonic gravity-anomaly reference field for gravity-map-matching navigation (GPS-denied alt-PNT).

gravity_sh

Full tesseral spherical-harmonic geopotential — the EGM2008 field to degree/order 70, the high-degree gravity model the numerical propagator’s crate::forces zonal-only field was missing.

gse_sim

Ground-Support-Equipment signal-in-space / observable simulator and the end-to-end PNT performance loop — the GSE half of the deep-space build (D4.2 + D4.3).

handoff

Optical ↔ RF measurement handoff — the receiver state-and-covariance transfer when the active PNT measurement type switches between a tight optical modality (small measurement noise R) and a loose RF modality (large R).

holdover

GNSS-denied clock holdover.

hybrid

Hybrid quantum + classical PNT: composing the clock-holdover and inertial models into one combined estimator.

hybrid_integrity

Joint availability / precision / integrity figure of merit for a heterogeneous optical + RF PNT service (P5), plus the hybrid-optical-rf scenario that drives it end-to-end.

igrf

IGRF-14 geomagnetic main-field model — an alternative-PNT signal source.

impairment_eval

AI-algorithm evaluation testbed for RF-impairment detection — the “Characterisation and Evaluation of Machine-Learning Techniques” layer.

impairment_ml

Learned RF-impairment detectors for the optimism-gap study.

impairment_study

The optimism-gap study: per-class AUC, the distribution-shift optimism gap, the experiment grid, and the ID-only gap predictor.

inertial

Inertial navigation: strapdown INS mechanization and the accelerometer error models (classical and cold-atom) a GNSS-denied coast dead-reckons on.

integrator

Adaptive numerical ODE integration: classical RK4 with step-doubling control, and a Dormand–Prince RK5(4) embedded pair.

integrity_impact

Detection-miss → integrity-impact mapping (context-aware alert limits).

interchange

Kshana Interchange Format (KIF) — a neutral, versioned, self-describing envelope for Kshana artifacts (scenarios, run results, trade studies, …).

intersat_range

Inter-satellite range / range-rate observables and their planar measurement Jacobians — the per-link measurement model for cislunar observability analysis.

ionex

IONEX-style total-electron-content (TEC) maps and the ionospheric range delay.

jamming

RF interference (jamming) model: J/S → effective C/N₀ → loss of lock.

jd2

Two-part (high-precision) Julian dates.

kalman

Two-state Kalman clock estimator.

lambda

GNSS carrier-phase integer ambiguity resolution — the LAMBDA approach (Teunissen 1995): integer least-squares with a decorrelating integer (Z) transform and a closed-form bootstrapped success rate.

launch

Launch-window & ascent geometry: the two-body relations a mission analyst uses at the trade-study tier to turn a launch-site latitude and a target orbit into launch azimuth(s), the minimum reachable inclination, the Earth-rotation velocity bonus, plane-change (dogleg) Δv, and the number of daily launch opportunities.

linkbudget

Deep-space communications link budget — the Friis transmission account that turns transmit power, antenna gains, range and noise temperature into the carrier-to-noise-density C/N₀, the energy-per-bit-to-noise-density Eb/N₀, and the link margin over a required Eb/N₀. This is the telecom-design half of a deep-space mission, the companion to the navigation observable model in crate::radiometric: the navigation kernel says where the spacecraft is from the signal’s timing; the link budget says whether the signal closes at all across the same Earth–Mars range.

lunar

Cislunar PNT integrity: ARAIM for a LunaNet-style lunar navigation service.

lunar_beacon

Surface-beacon augmentation of a lunar navigation service (L08, L09).

lunar_combination

Joint multi-technique lunar OD + clock batch estimator (a SIMULATED network).

lunar_dpnt

Lunar differential PNT (a lunar DGNSS / SBAS analogue): a fixed reference station at a known lunar-surface location computes per-satellite differential corrections from a Moonlight / LCNS-class constellation, and a roving user applies them so the common-mode orbit + clock errors cancel — leaving only a residual that grows with the user↔reference baseline (spatial decorrelation) — plus user protection levels that reuse the crate’s DO-229E SBAS machinery.

lunar_frame

IAU 2015 / WGCCRE lunar body-fixed orientation — the Mean-Earth/polar-axis (ME) frame.

lunar_frame_predict

Real-time lunar frame/ephemeris prediction error — derived endogenously.

lunar_frame_realise

Lunar reference-frame realisation — estimate a frame datum from a network of points.

lunar_interop

Lunar interoperability export — the lunar reference frame, lunar time scale and lunar ephemeris emitted in LunaNet/IOAG-aligned, CCSDS-based interchange forms with round-trip / field conformance.

lunar_od

Moon-centred force model for lunar precise orbit determination — the selenocentric analogue of crate::precise_od::PreciseForceModel.

lunar_perturbed

Perturbed lunar-constellation ephemeris: an Elliptical Lunar Frozen Orbit (ELFO) / LCNS-class relay propagated under lunar J2 + C22 plus Earth (and optional Sun) third-body gravity, in a Moon-centred inertial (MCI) frame.

lunar_service

Lunar navigation service-volume analysis: DOP / coverage / availability and generalised lunar ARAIM protection levels over a lunar surface region, from a Moonlight / LCNS-class lunar-orbit constellation.

lunar_time

Lunar coordinate time scale (LTC/TCL) and the relativistic Earth↔Moon clock rate.

lunar_time_budget

Coordinated Lunar Time (LTC) end-to-end time-error budget over a τ grid.

lunar_time_budget_scenario

lunar-time-budget scenario — a runnable wrapper over the Coordinated Lunar Time (LTC) end-to-end time-error budget (crate::lunar_time_budget).

lunar_vlbi

Lunar geodetic VLBI delay observable for an Earth baseline observing a lunar beacon.

maneuver

Impulsive / finite-burn maneuvers, a Lambert two-body transfer solver, and a porkchop (departure × arrival C3 / arrival-V∞) sweep — the maneuver-modeling and trajectory-design beachhead.

mapmatch

Map-matching measurement model for terrain-/gravity-referenced navigation.

mars_atmos

Mars neutral-atmosphere density and atmospheric-drag acceleration.

mars_frame

IAU 2009 Mars body-fixed orientation — the rotation from Mars-centred inertial (≈J2000/ICRF) to the Mars body-fixed frame.

mars_pnt

Mars PNT — a simulated MARCONI-style relay constellation at Mars plus reference user scenarios, run through the D3.1 joint one-way + two-way radiometric fusion estimator (D3.2/D3.3).

mcda

Multi-Criteria Decision Analysis (MCDA).

models

Stochastic clock and error models — the noise processes a scenario samples to drive a run.

monitor_network

Sparse-monitor-network detection sizing: how many surveyed, known-location monitor receivers does it take to catch a wide-area / orbital-scale spoof or jam?

navsignal

Nav-signal modulation, correlation and code-tracking performance.

nma_budget

Navigation-message-authentication (TESLA/OSNMA) budget sizing: turns the assertion “an OSNMA-style authentication scheme fits an AFS (autonomous-formation-flying / augmented-navigation-service) message and timing budget” into a sized result — the authentication overhead as a fraction of the nav-data rate, a bounded authentication latency, and the forgery-resistance figures.

nutation

IAU 2000B nutation and the full TEME→GCRS/J2000 inertial reduction.

observability_gramian

Observability-Gramian-over-arc core for planar cislunar tracking (paper P6).

oem

CCSDS Orbit Ephemeris Message (OEM) writer.

omm

CCSDS OMM (Orbit Mean-Elements Message, 502.0-B-2) writer.

optical_availability

Optical ground-network availability — the clear-sky / pointing availability of a free-space optical PNT link, and the diversity gain of an N-station network. An optical link is weather-limited: a single site is available only when its sky is clear and the terminal can point and acquire. Distributing several sites across uncorrelated weather systems raises the network availability toward unity — the P5 Table 2 / Fig 1b argument.

optical_linkbudget

Optical (1550 nm) two-way link budget — the photonic companion to the RF crate::linkbudget module. Where the RF budget turns EIRP / G/T / range into a carrier-to-noise density, the optical budget turns transmit power, aperture, range and detection efficiency into a detected-photon rate, and from that photon count into a photon-limited ranging precision and a diffraction-limited beam footprint. This is the optical column of the P5 heterogeneous-PNT table.

orbit

Keplerian-orbit propagation and GNSS line-of-sight visibility.

orbit_determination

Orbit determination: recover a satellite’s orbital state from ground-station tracking.

particle_filter

Sequential-importance-resampling (SIR) particle filter.

passes

Ground-station pass prediction: the time-domain rise/set scheduler that turns an orbit + a ground station + an elevation mask into the list of visibility passes (AOS, TCA, LOS, maximum elevation, duration) over a window — the ground-segment planning query the static look-angle primitives in crate::frames (look_angles/elevation/is_visible) do not provide on their own.

permalink

Shareable scenario permalinks (self-contained Base64, RFC 4648).

powerlaw

IEEE-1139 power-law clock-noise model: the five-coefficient PSD ↔ Allan-variance conversion, with first-class support for the flicker-FM floor.

precession

IAU 2006 precession: Fukushima–Williams angles and the precession rotation matrix.

precise_od

Full-force precise orbit determination from position observations — the precise estimator that fits Kshana’s complete force model (EGM2008 tesseral gravity + solid/ocean/ atmospheric tides + Sun/Moon third body + SRP + drag + Schwarzschild/Lense–Thirring GR) to a track of inertial position fixes and reports the post-fit residuals in the radial/transverse/ normal (RTN) frame.

propagator

Numerical orbit propagator: a configurable force model integrated by the adaptive Runge–Kutta driver, the first non-analytic propagator in Kshana (the rest of the orbit stack is the analytic SGP4/SDP4 of crate::sgp4).

pvt

Single-point positioning (SPP): a position fix from real measurements.

qtrade

Unified quantum-vs-classical trade evidence.

quantum_devices

Quantum device error-model library + representativeness.

quantum_faults

Fault / anomaly detection for quantum PNT systems.

quantum_nav_od

GNSS-free quantum spacecraft navigation.

quantum_trade

Quantum-vs-classical PNT trade engine + measured-ADEV ingestion + GNSS-denied resilience envelope — the ground-side decision artifacts a quantum-PNT consortium needs (ESA AO/1-13503).

radiometric

Radiometric observable corrections for deep-space tracking — the light-time solution and the Shapiro relativistic delay that turn a geometric range into the time a signal actually takes to travel between two bodies.

raim

Snapshot Receiver Autonomous Integrity Monitoring (RAIM).

realdata

Real-data ingest adapters for the optimism-gap probe.

realtime_frame_eop

realtime-frame-eop scenario — a runnable wrapper over the real-time lunar frame / Earth-orientation prediction budget (crate::frame_eop).

reentry

Ballistic re-entry corridor (Allen–Eggers): the closed-form analytic entry of a non-lifting body through an exponential atmosphere at a constant flight-path angle. It turns an entry velocity + flight-path angle into peak deceleration, the velocity and altitude where that peak occurs, and the peak-heating velocity — the pre-Phase-A corridor numbers an EDL analyst brackets before any high-fidelity trajectory or aerothermal run.

registry

Scenario pack registry — the dispatch seam.

report

Result reporting: assembling a run’s figures of merit, samples and provenance into the structured result returned to callers.

representativeness

Representativeness & gaps-to-flight ledger.

resilience

PNT-resilience scoring & the decision-instability of single-number ratings.

rinex

RINEX 3 navigation-message (broadcast ephemeris) parser.

rinex_obs

RINEX 3.0x / 4.00 observation-file parser.

run

Single-run orchestration: driving a parsed scenario through the estimator and scoring it into a result.

sbas

SBAS / DO-229E integrity: weighted-least-squares protection levels, the L1/L5 dual-frequency ionosphere-free combination, and a DO-316/DO-229E compliance map.

scenario

Scenario model: the parsed TOML scenario the engine classifies, dispatches and runs.

sdr

Software-defined-receiver front end: raw IQ IF -> correlator taps.

security

Spoofing-detection security figure of merit.

sgp4

SGP4/SDP4 analytical orbit propagation.

sp3

SP3-c/d precise-ephemeris reader and writer.

space_packet

CCSDS Space Packet Protocol (CCSDS 133.0-B) primary-header framing: the standards-compliant TM/TC packet structure ground systems and on-board software exchange. This is the simulation/test-level bridge that lets any Kshana scenario output be wrapped as a conformant packet stream (or a captured stream be parsed back), the “speak the agency packet format” interop layer.

space_weather

Space-weather environment model: solar (F10.7) and geomagnetic (Kp/ap) activity indices and their first-order effect on thermospheric neutral density — the activity dependence the static US-Standard-Atmosphere-1976 (crate::forces::atmospheric_density) deliberately omits.

spoof

Active time-spoofing attack demonstrator.

spoof_capture

Tracking-loop pull-in spoof-capture model: does the spoofer actually capture the loop?

spoof_detect

The runnable spoof-detect scenario — the product surface over crate::spoof_monitors::CombinedSpoofDetector.

spoof_monitors

RF-layer spoofing monitors: AGC received-power and signal-quality (SQM).

study

study mode: run a crate::suite::Suite into one aggregated, comparable artifact.

suite

Scenario-suite manifest: a named SET of scenarios run together.

sweep

Trade-study parameter sweeps.

tides

Solid Earth, ocean, and atmospheric tides on the geopotential (IERS Conventions 2010, Ch.6).

timegeo

Geometric time-transfer corrections: the Sagnac effect and GNSS common-view.

timescales

Time scales and the Julian-date API.

timetransfer

Time-and-frequency transfer: TWSTFT, GNSS common-view, PPP and free-space-optical link transfer precision.

timetransfer_adv

Advanced time-and-frequency transfer.

timetransfer_chain

Trusted quantum timing — end-to-end time-transfer chain, secure dissemination and a quantum-vs-classical trade.

tle

Two-line element set (TLE) ingestion.

tpl

Timing Protection Level (TPL) under time-synchronization attack.

types

Shared scalar and specification types used across the engine (e.g. Seconds, ModelSpec).

verification

Machine-checked verification matrix.

wahba

Wahba’s problem: optimal three-axis attitude from weighted vector observations.

walker

Walker-delta constellation design on the validated SGP4 core.