# Sidereon v0.11.1 - Table of Contents

> Satellite toolkit for Elixir with SGP4 propagation, coordinate transforms,
GNSS positioning, orbit determination, conjunction assessment, pass
prediction, and a Rust NIF backend.

## Pages

- [sidereon](readme.md)
- [sidereon: GNSS and astrodynamics in Elixir](sidereon.md)
- [Changelog](changelog.md)
- [GNSS Positioning](gnss_positioning.md)

- Guides
  - [Predict Passes with Doppler](pass_prediction.md)
  - [Accuracy &amp; Validation](accuracy.md)
  - [Data Acquisition](data_acquisition.md)
  - [GNSS Constellation Catalogs](gnss_constellation_catalog.md)

## Modules

- [Sidereon.Astro.Almanac](Sidereon.Astro.Almanac.md): Almanac event finders.
- [Sidereon.Astro.Anomaly](Sidereon.Astro.Anomaly.md): Kepler anomaly conversions and two-body propagation for classical elements.

- [Sidereon.Astro.Equinoctial](Sidereon.Astro.Equinoctial.md): Equinoctial and modified equinoctial orbital element conversions.

- [Sidereon.Astro.Equinoctial.EquinoctialElements](Sidereon.Astro.Equinoctial.EquinoctialElements.md): Equinoctial orbital elements.

- [Sidereon.Astro.Equinoctial.ModifiedEquinoctialElements](Sidereon.Astro.Equinoctial.ModifiedEquinoctialElements.md): Modified equinoctial orbital elements.

- [Sidereon.Astro.Observe](Sidereon.Astro.Observe.md): General topocentric body observation.
- [Sidereon.Astro.Relative](Sidereon.Astro.Relative.md): RSW, RTN, RIC, LVLH relative frames and Clohessy-Wiltshire motion.

- [Sidereon.Astro.Relative.State](Sidereon.Astro.Relative.State.md): Cartesian state used by relative-frame and Clohessy-Wiltshire helpers.

- [Sidereon.Bodies](Sidereon.Bodies.md): Ground-observer Sun and Moon geometry.
- [Sidereon.CCSDS.CDM](Sidereon.CCSDS.CDM.md): Parse and encode CCSDS Conjunction Data Messages (CDM).
- [Sidereon.CCSDS.CDM.ObjectData](Sidereon.CCSDS.CDM.ObjectData.md): Object-specific data block inside a parsed CCSDS CDM.

- [Sidereon.CCSDS.OEM](Sidereon.CCSDS.OEM.md): Parse and encode CCSDS Orbit Ephemeris Messages (OEM).
- [Sidereon.CCSDS.OEM.Covariance](Sidereon.CCSDS.OEM.Covariance.md): One 6x6 covariance block inside a parsed CCSDS OEM segment.
- [Sidereon.CCSDS.OEM.Metadata](Sidereon.CCSDS.OEM.Metadata.md): Metadata block for one CCSDS OEM segment.

- [Sidereon.CCSDS.OEM.Segment](Sidereon.CCSDS.OEM.Segment.md): One metadata/data segment of a CCSDS OEM.

- [Sidereon.CCSDS.OEM.State](Sidereon.CCSDS.OEM.State.md): One Cartesian state sample inside a parsed CCSDS OEM segment.
- [Sidereon.CCSDS.OPM](Sidereon.CCSDS.OPM.md): Parse and encode CCSDS Orbit Parameter Messages (OPM).
- [Sidereon.CCSDS.OPM.Covariance](Sidereon.CCSDS.OPM.Covariance.md): Optional OPM 6x6 covariance. `matrix` is a row-major list of six six-element
rows.

- [Sidereon.CCSDS.OPM.Keplerian](Sidereon.CCSDS.OPM.Keplerian.md): Optional OPM Keplerian elements.
- [Sidereon.CCSDS.OPM.Maneuver](Sidereon.CCSDS.OPM.Maneuver.md): One OPM maneuver block. `dv_km_s` is the `{x, y, z}` delta-v in the maneuver
reference frame.

- [Sidereon.CCSDS.OPM.Metadata](Sidereon.CCSDS.OPM.Metadata.md): OPM metadata block.

- [Sidereon.CCSDS.OPM.Spacecraft](Sidereon.CCSDS.OPM.Spacecraft.md): Optional OPM spacecraft parameters. Every field is optional.

- [Sidereon.CCSDS.OPM.State](Sidereon.CCSDS.OPM.State.md): OPM Cartesian state vector.
- [Sidereon.Collision](Sidereon.Collision.md): Collision probability calculation for close approaches.
- [Sidereon.Collision.Result](Sidereon.Collision.Result.md): Result of a collision-probability evaluation.

- [Sidereon.Covariance](Sidereon.Covariance.md): Covariance matrix helpers for conjunction and orbit analysis.
- [Sidereon.Drag](Sidereon.Drag.md): Atmospheric drag parameters, acceleration, and decay estimates.

- [Sidereon.Drag.DecayEstimate](Sidereon.Drag.DecayEstimate.md): Estimated decay time and reentry state.

- [Sidereon.Drag.Parameters](Sidereon.Drag.Parameters.md): Ballistic drag settings passed to propagation and drag-force calculations.

- [Sidereon.Drag.SpaceWeather](Sidereon.Drag.SpaceWeather.md): Space-weather inputs for the core drag model.

- [Sidereon.Encounter](Sidereon.Encounter.md): Encounter geometry helpers for conjunction assessment.
- [Sidereon.Encounter.Frame](Sidereon.Encounter.Frame.md): Relative encounter geometry at a common epoch.
- [Sidereon.Forces.J2](Sidereon.Forces.J2.md): Earth's oblateness (J2) perturbation force model.

- [Sidereon.Forces.TwoBody](Sidereon.Forces.TwoBody.md): Standard Keplerian Two-Body gravity force model.

- [Sidereon.Format.OMM.Epoch](Sidereon.Format.OMM.Epoch.md): UTC calendar epoch carried by an OMM `EPOCH` field.
- [Sidereon.GNSS.Antex](Sidereon.GNSS.Antex.md): Parser and lookup helpers for ANTEX 1.4 receiver and satellite antenna blocks.
- [Sidereon.GNSS.Bias](Sidereon.GNSS.Bias.md): DCB and OSB bias products backed by the core bias parsers.

- [Sidereon.GNSS.Bias.Record](Sidereon.GNSS.Bias.Record.md): One bias record decoded from a DCB or OSB product.

- [Sidereon.GNSS.Bias.Set](Sidereon.GNSS.Bias.Set.md): Parsed DCB or OSB bias product.

- [Sidereon.GNSS.Broadcast.ClockPolynomial](Sidereon.GNSS.Broadcast.ClockPolynomial.md): Broadcast satellite-clock polynomial.
- [Sidereon.GNSS.Broadcast.CnavCorrections](Sidereon.GNSS.Broadcast.CnavCorrections.md): Core-evaluated CNAV single-frequency clock corrections in seconds.

- [Sidereon.GNSS.Broadcast.CnavParameters](Sidereon.GNSS.Broadcast.CnavParameters.md): CNAV/CNAV-2 fields that have no LNAV counterpart.

- [Sidereon.GNSS.Broadcast.DetailedRecord](Sidereon.GNSS.Broadcast.DetailedRecord.md): One broadcast record with issue, time tags, group delays, and CNAV fields.

- [Sidereon.GNSS.Broadcast.GlonassRecord](Sidereon.GNSS.Broadcast.GlonassRecord.md): One GLONASS broadcast state-vector record.
- [Sidereon.GNSS.Broadcast.GroupDelays](Sidereon.GNSS.Broadcast.GroupDelays.md): Broadcast group-delay fields preserved from a NAV record.

- [Sidereon.GNSS.Broadcast.IonoCorrections](Sidereon.GNSS.Broadcast.IonoCorrections.md): Broadcast ionosphere coefficients parsed from a RINEX NAV header.
- [Sidereon.GNSS.Broadcast.Issue](Sidereon.GNSS.Broadcast.Issue.md): Broadcast issue value plus the navigation-message family that carried it.

- [Sidereon.GNSS.Broadcast.KeplerianElements](Sidereon.GNSS.Broadcast.KeplerianElements.md): Broadcast Keplerian orbital elements.
- [Sidereon.GNSS.Broadcast.KlobucharAlphaBeta](Sidereon.GNSS.Broadcast.KlobucharAlphaBeta.md): Klobuchar alpha and beta ionosphere coefficients.
- [Sidereon.GNSS.Broadcast.Record](Sidereon.GNSS.Broadcast.Record.md): One GPS, Galileo, or BeiDou broadcast ephemeris record from RINEX NAV.
- [Sidereon.GNSS.Broadcast.State](Sidereon.GNSS.Broadcast.State.md): A broadcast-evaluated satellite state at one epoch.
- [Sidereon.GNSS.Broadcast.WeekTow](Sidereon.GNSS.Broadcast.WeekTow.md): GNSS week and time-of-week tagged with its native time scale.

- [Sidereon.GNSS.BroadcastComparison](Sidereon.GNSS.BroadcastComparison.md): Broadcast-ephemeris accuracy: compare a broadcast navigation product against a
precise SP3 product over a window.
- [Sidereon.GNSS.BroadcastComparison.Report](Sidereon.GNSS.BroadcastComparison.Report.md): The result of a broadcast and precise product comparison.
- [Sidereon.GNSS.BroadcastComparison.Stats](Sidereon.GNSS.BroadcastComparison.Stats.md): Orbit and clock difference statistics for one satellite (or the overall set).
- [Sidereon.GNSS.Constellation.Catalog](Sidereon.GNSS.Constellation.Catalog.md): The result of a lenient catalog build: the records that resolved, plus the
OMM entries that did not.
- [Sidereon.GNSS.Constellation.Diff](Sidereon.GNSS.Constellation.Diff.md): Change report between two GNSS constellation catalog snapshots.

- [Sidereon.GNSS.Constellation.NavcenStatus](Sidereon.GNSS.Constellation.NavcenStatus.md): A parsed row from NAVCEN's GPS constellation status table.

- [Sidereon.GNSS.Constellation.Record](Sidereon.GNSS.Constellation.Record.md): A normalized GNSS satellite identity record.
- [Sidereon.GNSS.Constellation.SkippedOmm](Sidereon.GNSS.Constellation.SkippedOmm.md): An OMM entry that `Sidereon.GNSS.Constellation.from_celestrak_omm_lenient/2`
could not resolve to a `Record` for the requested system.
- [Sidereon.GNSS.Constellation.Validation](Sidereon.GNSS.Constellation.Validation.md): Validation report for a GNSS constellation catalog.
- [Sidereon.GNSS.Data.AbsentCenter](Sidereon.GNSS.Data.AbsentCenter.md): SP3 center that did not contribute to a merge.

- [Sidereon.GNSS.Data.Contributor](Sidereon.GNSS.Data.Contributor.md): SP3 center that contributed a product to a merge.

- [Sidereon.GNSS.Data.MergeReport](Sidereon.GNSS.Data.MergeReport.md): Audit report for merged SP3 acquisition.

- [Sidereon.GNSS.Data.Product](Sidereon.GNSS.Data.Product.md): Pure identity for one GNSS archive product.

- [Sidereon.GNSS.Data.TerrainFetchReport](Sidereon.GNSS.Data.TerrainFetchReport.md): Result partition for region and tile-list terrain prefetches.

- [Sidereon.GNSS.Ephemeris](Sidereon.GNSS.Ephemeris.md): A unified satellite-ephemeris sampling surface over precise SP3 products and
broadcast navigation messages.
- [Sidereon.GNSS.Ephemeris.Row](Sidereon.GNSS.Ephemeris.Row.md): One sampled satellite state at one epoch in the unified ephemeris table.
- [Sidereon.GNSS.NMEA](Sidereon.GNSS.NMEA.md): NMEA 0183 parsing, epoch accumulation, and GGA writing.

- [Sidereon.GNSS.NMEA.Accumulator](Sidereon.GNSS.NMEA.Accumulator.md): Resource-backed incremental NMEA accumulator.

- [Sidereon.GNSS.NMEA.Sentence](Sidereon.GNSS.NMEA.Sentence.md): One decoded NMEA sentence.

- [Sidereon.GNSS.NMEA.Snapshot](Sidereon.GNSS.NMEA.Snapshot.md): One accumulated NMEA epoch snapshot.

- [Sidereon.GNSS.Ntrip](Sidereon.GNSS.Ntrip.md): NTRIP client helpers and stream process.
- [Sidereon.GNSS.Ntrip.CasRecord](Sidereon.GNSS.Ntrip.CasRecord.md): NTRIP CAS record.
- [Sidereon.GNSS.Ntrip.GgaPosition](Sidereon.GNSS.Ntrip.GgaPosition.md): Position fields for NTRIP VRS GGA output.

- [Sidereon.GNSS.Ntrip.NetRecord](Sidereon.GNSS.Ntrip.NetRecord.md): NTRIP NET record.
- [Sidereon.GNSS.Ntrip.OtherRecord](Sidereon.GNSS.Ntrip.OtherRecord.md): Unknown NTRIP sourcetable record with fields preserved.
- [Sidereon.GNSS.Ntrip.Sourcetable](Sidereon.GNSS.Ntrip.Sourcetable.md): Parsed NTRIP sourcetable resource and record list.

- [Sidereon.GNSS.Ntrip.StrRecord](Sidereon.GNSS.Ntrip.StrRecord.md): NTRIP STR record.
- [Sidereon.GNSS.Ntrip.Stream](Sidereon.GNSS.Ntrip.Stream.md): GenServer that owns an NTRIP stream connection.

- [Sidereon.GNSS.PPPCorrections](Sidereon.GNSS.PPPCorrections.md): Precomputed, state-independent PPP per-range corrections for the static-arc
float/fixed solve: solid-earth tide, carrier-phase wind-up, and satellite
antenna PCO/PCV.
- [Sidereon.GNSS.Positioning.Solution](Sidereon.GNSS.Positioning.Solution.md): A single-point-positioning solution at one receive epoch.
- [Sidereon.GNSS.Positioning.SourcedSolution](Sidereon.GNSS.Positioning.SourcedSolution.md): A single-point-positioning solution paired with the provenance of the
ephemeris that produced it.
- [Sidereon.GNSS.PreciseEphemeris](Sidereon.GNSS.PreciseEphemeris.md): A precise-ephemeris source built directly from samples, with no SP3 text in the
loop.
- [Sidereon.GNSS.PreciseEphemerisSample](Sidereon.GNSS.PreciseEphemerisSample.md): One precise-ephemeris sample: a satellite's ECEF position (and optional clock)
at one epoch, in SI units.
- [Sidereon.GNSS.PrecisePositioning.FixedSolution](Sidereon.GNSS.PrecisePositioning.FixedSolution.md): Static multi-epoch integer-fixed carrier-phase solution.

- [Sidereon.GNSS.PrecisePositioning.MultiEpochSolution](Sidereon.GNSS.PrecisePositioning.MultiEpochSolution.md): Static multi-epoch float-ambiguity phase positioning solution.

- [Sidereon.GNSS.PrecisePositioning.Solution](Sidereon.GNSS.PrecisePositioning.Solution.md): Float-ambiguity phase positioning solution for one epoch.

- [Sidereon.GNSS.QC.ClockJump](Sidereon.GNSS.QC.ClockJump.md): Detected receiver-clock jump.
- [Sidereon.GNSS.QC.CycleSlipQc](Sidereon.GNSS.QC.CycleSlipQc.md): Aggregate dual-frequency cycle-slip counts.
- [Sidereon.GNSS.QC.DataGap](Sidereon.GNSS.QC.DataGap.md): Detected gap between adjacent observation epochs.
- [Sidereon.GNSS.QC.MultipathReport](Sidereon.GNSS.QC.MultipathReport.md): MP1/MP2 multipath RMS report.
- [Sidereon.GNSS.QC.MultipathStats](Sidereon.GNSS.QC.MultipathStats.md): RMS statistics for one multipath series.
- [Sidereon.GNSS.QC.ObservationAntenna](Sidereon.GNSS.QC.ObservationAntenna.md): Antenna identity from `ANT # / TYPE`.
- [Sidereon.GNSS.QC.ObservationFinding](Sidereon.GNSS.QC.ObservationFinding.md): Compact lint finding retained by a QC report.
- [Sidereon.GNSS.QC.ObservationHeader](Sidereon.GNSS.QC.ObservationHeader.md): Header metadata copied into a QC report.
- [Sidereon.GNSS.QC.ObservationNote](Sidereon.GNSS.QC.ObservationNote.md): Non-fatal QC note.
- [Sidereon.GNSS.QC.ObservationReceiver](Sidereon.GNSS.QC.ObservationReceiver.md): Receiver identity from `REC # / TYPE / VERS`.
- [Sidereon.GNSS.QC.ObservationReport](Sidereon.GNSS.QC.ObservationReport.md): RINEX observation QC report.
- [Sidereon.GNSS.QC.ObservationTime](Sidereon.GNSS.QC.ObservationTime.md): Observation epoch with an optional RINEX time-scale label.
- [Sidereon.GNSS.QC.SatelliteMultipath](Sidereon.GNSS.QC.SatelliteMultipath.md): Per-satellite MP1/MP2 RMS row.
- [Sidereon.GNSS.QC.SatelliteObservation](Sidereon.GNSS.QC.SatelliteObservation.md): Per-satellite observation completeness row.
- [Sidereon.GNSS.QC.SatelliteSignal](Sidereon.GNSS.QC.SatelliteSignal.md): Per-satellite, per-code observation completeness row.
- [Sidereon.GNSS.QC.SnrStats](Sidereon.GNSS.QC.SnrStats.md): Summary statistics over raw numeric S-code observations.
- [Sidereon.GNSS.QC.SsiHistogram](Sidereon.GNSS.QC.SsiHistogram.md): Histogram over RINEX SSI digits.
- [Sidereon.GNSS.QC.SystemCycleSlipQc](Sidereon.GNSS.QC.SystemCycleSlipQc.md): Per-constellation cycle-slip counts.
- [Sidereon.GNSS.QC.SystemMultipath](Sidereon.GNSS.QC.SystemMultipath.md): Per-constellation MP1/MP2 RMS row.
- [Sidereon.GNSS.QC.SystemObservation](Sidereon.GNSS.QC.SystemObservation.md): Per-constellation observation completeness row.
- [Sidereon.GNSS.QC.SystemSignal](Sidereon.GNSS.QC.SystemSignal.md): Per-constellation, per-code observation completeness row.
- [Sidereon.GNSS.RINEX.Clock](Sidereon.GNSS.RINEX.Clock.md): RINEX clock (`.CLK`) reader for satellite clock-bias records.
- [Sidereon.GNSS.RTCM](Sidereon.GNSS.RTCM.md): RTCM 3.x differential-GNSS stream decoding.
- [Sidereon.GNSS.RTK.FixedBaselineSolution](Sidereon.GNSS.RTK.FixedBaselineSolution.md): Integer-fixed RTK baseline solution from code/carrier double differences.

- [Sidereon.GNSS.RTK.FloatBaselineSolution](Sidereon.GNSS.RTK.FloatBaselineSolution.md): Float RTK baseline solution from code/carrier double differences.

- [Sidereon.GNSS.RTK.MovingBaseline](Sidereon.GNSS.RTK.MovingBaseline.md): Moving-baseline RTK: both receivers move each epoch (RTKLIB "moving-base").
- [Sidereon.GNSS.ReducedOrbit.Piecewise](Sidereon.GNSS.ReducedOrbit.Piecewise.md): A long position track approximated by a sequence of contiguous, independently
fitted `Sidereon.GNSS.ReducedOrbit` segments.
- [Sidereon.GNSS.SBAS](Sidereon.GNSS.SBAS.md): Satellite-based augmentation corrections.
- [Sidereon.GNSS.SBAS.LogBlock](Sidereon.GNSS.SBAS.LogBlock.md): One SBAS log block with decoded message metadata.
- [Sidereon.GNSS.SBAS.Message](Sidereon.GNSS.SBAS.Message.md): Decoded SBAS message metadata.
- [Sidereon.GNSS.SP3.State](Sidereon.GNSS.SP3.State.md): An SP3 satellite state at one epoch.
- [Sidereon.GNSS.SSR](Sidereon.GNSS.SSR.md): State-space GNSS corrections.
- [Sidereon.GNSS.SSR.ClockCorrection](Sidereon.GNSS.SSR.ClockCorrection.md): SSR clock correction.
- [Sidereon.GNSS.SSR.OrbitCorrection](Sidereon.GNSS.SSR.OrbitCorrection.md): SSR orbit correction.
- [Sidereon.GNSS.SSR.Solution](Sidereon.GNSS.SSR.Solution.md): SSR solution identity.
- [Sidereon.GNSS.Staleness](Sidereon.GNSS.Staleness.md): Product-staleness graceful degradation for time-varying GNSS products.
- [Sidereon.GNSS.Staleness.IonexSelection](Sidereon.GNSS.Staleness.IonexSelection.md): A selected IONEX product paired with its staleness metadata.
- [Sidereon.GNSS.Staleness.Policy](Sidereon.GNSS.Staleness.Policy.md): Staleness cap for product selection.
- [Sidereon.GNSS.Staleness.Sp3Selection](Sidereon.GNSS.Staleness.Sp3Selection.md): A selected SP3 product paired with its staleness metadata.
- [Sidereon.GNSS.Staleness.StalenessMetadata](Sidereon.GNSS.Staleness.StalenessMetadata.md): Structured description of the product staleness behind a selection result.
- [Sidereon.Geodetic](Sidereon.Geodetic.md): WGS84 geodetic position: latitude, longitude, altitude.

- [Sidereon.Geoid](Sidereon.Geoid.md): Geoid undulation lookup and orthometric/ellipsoidal height conversion.
- [Sidereon.ILS](Sidereon.ILS.md): Integer least-squares search helpers.

- [Sidereon.LeastSquares](Sidereon.LeastSquares.md): Generic data-driven trust-region least squares.
- [Sidereon.LeastSquares.DropOneReport](Sidereon.LeastSquares.DropOneReport.md): A leave-one-out sweep: the `base` solve over all rows, one `drops` solve per
masked residual row (in row order), and `cost_delta` giving how much the
optimum cost moves when each row is removed.

- [Sidereon.LeastSquares.Result](Sidereon.LeastSquares.Result.md): A single converged trust-region solve.
- [Sidereon.LookAngle](Sidereon.LookAngle.md): Topocentric look angle from a ground station to a satellite.

- [Sidereon.Observation](Sidereon.Observation.md): Observational-astronomy geometry primitives.
- [Sidereon.OrbitalElements](Sidereon.OrbitalElements.md): Classical (Keplerian) orbital elements and the two-body state transforms.
- [Sidereon.Pass](Sidereon.Pass.md): A satellite pass over a ground station.

- [Sidereon.Propagator](Sidereon.Propagator.md): High-precision numerical orbit propagation.
- [Sidereon.SGP4.Fit](Sidereon.SGP4.Fit.md): Result of inverse SGP4 TLE fitting.

- [Sidereon.SpaceWeather](Sidereon.SpaceWeather.md): Space-weather tables for drag and decay inputs.
- [Sidereon.SpaceWeather.Coverage](Sidereon.SpaceWeather.Coverage.md): J2000-second coverage bounds for a parsed space-weather table.

- [Sidereon.SpaceWeather.Policy](Sidereon.SpaceWeather.Policy.md): Lookup policy for rejecting lower-trust rows or monthly Ap defaults.

- [Sidereon.SpaceWeather.Sample](Sidereon.SpaceWeather.Sample.md): Space-weather values plus source metadata for one lookup.

- [Sidereon.Statistics](Sidereon.Statistics.md): Residual-distribution diagnostics: sample moments and normality tests.
- [Sidereon.Terrain](Sidereon.Terrain.md): DTED terrain loading and elevation lookup.

- [Sidereon.Terrain.Dted](Sidereon.Terrain.Dted.md): Handle for a DTED terrain directory.

- [Sidereon.Terrain.DtedTile](Sidereon.Terrain.DtedTile.md): Handle for one loaded DTED tile.

- Core
  - [Sidereon](Sidereon.md): Satellite toolkit for Elixir. SGP4 orbit propagation, coordinate
transformations, and ground station pass prediction.

  - [Sidereon.Elements](Sidereon.Elements.md): Canonical representation of satellite orbital elements.
  - [Sidereon.SGP4](Sidereon.SGP4.md): SGP4/SDP4 orbit propagation from Two-Line Element sets.

  - [Sidereon.TemeState](Sidereon.TemeState.md): Represents the position and velocity of a satellite in the TEME coordinate system.

- Coordinates
  - [Sidereon.Coordinates](Sidereon.Coordinates.md): Coordinate frame transformations for satellite state vectors.

- Ground Station
  - [Sidereon.Doppler](Sidereon.Doppler.md): Doppler shift calculation for satellite-ground links.
  - [Sidereon.Passes](Sidereon.Passes.md): Satellite pass prediction over a ground station.
  - [Sidereon.RF](Sidereon.RF.md): RF link budget primitives.

- Orbit Determination
  - [Sidereon.IOD](Sidereon.IOD.md): Initial Orbit Determination methods.
  - [Sidereon.Lambert](Sidereon.Lambert.md): Lambert problem solver (Battin's method).

- Space Environment
  - [Sidereon.Angles](Sidereon.Angles.md): Angular geometry calculations for satellites.
  - [Sidereon.Atmosphere](Sidereon.Atmosphere.md): Atmospheric density via the NRLMSISE-00 empirical model.
  - [Sidereon.Eclipse](Sidereon.Eclipse.md): Earth shadow (eclipse) prediction for satellites.
  - [Sidereon.Ephemeris](Sidereon.Ephemeris.md): JPL/NAIF SPK (DAF `.bsp`) ephemeris kernel reader.

- Conjunction
  - [Sidereon.Conjunction](Sidereon.Conjunction.md): Time-of-closest-approach and conjunction screening helpers.

- GNSS Positioning
  - [Sidereon.GNSS.Broadcast](Sidereon.GNSS.Broadcast.md): A parsed RINEX broadcast-navigation product (GPS LNAV, Galileo I/NAV+F/NAV,
BeiDou D1/D2, GLONASS).
  - [Sidereon.GNSS.CarrierPhase](Sidereon.GNSS.CarrierPhase.md): Dual-frequency carrier-phase linear combinations and the precise-positioning
prep tooling built on them: geometry-free and wide-lane phase, the
narrow-lane code, Melbourne-Wubbena, cycle-slip detection, and Hatch
carrier-smoothed code.
  - [Sidereon.GNSS.Constellation](Sidereon.GNSS.Constellation.md): GNSS constellation identity catalogs and validation helpers.
  - [Sidereon.GNSS.DGNSS](Sidereon.GNSS.DGNSS.md): Code-differential GNSS (DGPS) positioning over single-frequency pseudoranges.
  - [Sidereon.GNSS.Data](Sidereon.GNSS.Data.md): Cache-first acquisition for GNSS products and DTED terrain tiles.
  - [Sidereon.GNSS.Frequencies](Sidereon.GNSS.Frequencies.md): Canonical GNSS carrier-frequency lookups.
  - [Sidereon.GNSS.Geometry](Sidereon.GNSS.Geometry.md): Satellite-geometry and mission-planning layer above the GNSS observables:
from a static receiver position and a precise (SP3) ephemeris, answer the
three planning questions: which satellites are visible, how good is the
geometry (dilution of precision), and when does each satellite rise and set.
  - [Sidereon.GNSS.Ionosphere](Sidereon.GNSS.Ionosphere.md): Single-frequency ionospheric group-delay corrections.
  - [Sidereon.GNSS.IonosphereFree](Sidereon.GNSS.IonosphereFree.md): The dual-frequency ionosphere-free linear combination for code and phase.
  - [Sidereon.GNSS.Navigation.LNAV](Sidereon.GNSS.Navigation.LNAV.md): GPS L1 C/A LNAV navigation message synthesis and decoding (subframes 1-3).
  - [Sidereon.GNSS.Navigation.LNAV.Ephemeris](Sidereon.GNSS.Navigation.LNAV.Ephemeris.md): GPS LNAV clock and ephemeris parameters in engineering units.
  - [Sidereon.GNSS.Observables](Sidereon.GNSS.Observables.md): Predict the GNSS observables a receiver at a known ECEF position would see for
a satellite, from a precise (SP3) or broadcast ephemeris source.
  - [Sidereon.GNSS.Positioning](Sidereon.GNSS.Positioning.md): GNSS single-point positioning (SPP): recover a receiver position, clock bias,
and geometry diagnostics from one epoch of pseudorange observations against a
precise SP3 ephemeris or a broadcast navigation product.
  - [Sidereon.GNSS.PrecisePositioning](Sidereon.GNSS.PrecisePositioning.md): Carrier-phase precise-positioning primitives.
  - [Sidereon.GNSS.QC](Sidereon.GNSS.QC.md): Measurement-quality control for single-point positioning.
  - [Sidereon.GNSS.RINEX.Observations](Sidereon.GNSS.RINEX.Observations.md): RINEX 3 observation products: parse a station's observation file, expose its
header (including the surveyed `APPROX POSITION XYZ`, optional antenna
`DELTA H/E/N` offset, and carrier phase-shift records), and extract the
single-frequency pseudoranges that `Sidereon.GNSS.Positioning.solve/4` consumes.
  - [Sidereon.GNSS.RTK](Sidereon.GNSS.RTK.md): RTK-facing carrier/code double-difference primitives.
  - [Sidereon.GNSS.ReducedOrbit](Sidereon.GNSS.ReducedOrbit.md): A compact, fitted mean-element approximation of a satellite's orbit.
  - [Sidereon.GNSS.SP3](Sidereon.GNSS.SP3.md): SP3-c / SP3-d precise-ephemeris products (IGS precise orbits + clocks).
  - [Sidereon.GNSS.Signal.CA](Sidereon.GNSS.Signal.CA.md): GPS L1 coarse/acquisition (C/A) code generation and correlation.
  - [Sidereon.GNSS.Signal.Correlator](Sidereon.GNSS.Signal.Correlator.md): Baseband simulation, correlation, and acquisition for the GPS L1 C/A signal.
  - [Sidereon.GNSS.Time](Sidereon.GNSS.Time.md): Epoch conversions shared by the GNSS correction wrappers.
  - [Sidereon.GNSS.Troposphere](Sidereon.GNSS.Troposphere.md): Neutral-atmosphere (tropospheric) signal-delay corrections.
  - [Sidereon.GNSS.Velocity](Sidereon.GNSS.Velocity.md): Recover receiver velocity and clock drift from one epoch of range-rate or
Doppler observations against a precise SP3 or broadcast ephemeris source.

- Data Sources
  - [Sidereon.Constellation](Sidereon.Constellation.md): Manage and propagate satellite constellations.

- Batch Analysis
  - [Sidereon.Coverage](Sidereon.Coverage.md): Batch single-epoch coverage helpers backed by the Rust core.

- Format
  - [Sidereon.Format.OMM](Sidereon.Format.OMM.md): Parse and encode CCSDS Orbit Mean-Elements Messages (OMM).
  - [Sidereon.Format.TLE](Sidereon.Format.TLE.md): Parse and encode Two-Line Element sets.

