# Changelog
All notable changes to this project are documented here. The format is based on
[Keep a Changelog](https://keepachangelog.com/en/1.1.0/), and this project
adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
## [Unreleased]
## [0.14.1] - 2026-06-09
### Fixed
- Re-published the 0.14.x release line with precompiled-NIF checksums matching
the final GitHub release assets built against `astrodynamics-gnss` 0.9.4. The
0.14.0 package was published before the final checksum file was committed, so
supported platforms could reject the downloaded precompiled archive and fall
back poorly. No API or numerical behavior changed from 0.14.0.
## [0.14.0] - 2026-06-08
### Added
- `Orbis.GNSS.SP3.to_iodata/2` serializes an `%Orbis.GNSS.SP3{}` product back to
standard SP3-c / SP3-d text — the inverse of the reader, so a read → `merge/2`
→ write pipeline emits a single standard SP3 file any reader consumes. Pure and
deterministic; header fields are derived from the product; a satellite absent
at an epoch is written as the SP3 missing-orbit sentinel (so a quarantined
merge cell re-reads as missing, never a fabricated position). Round-trips to
SP3 format precision (mm / sub-ns) for position-only and position+velocity,
multi-constellation products.
- `Orbis.GNSS.Data.write_sp3/3` writes a product to disk with the fetch layer's
atomic-commit discipline (same-directory temp file + `File.rename/2`), with an
optional `gzip: true` for the gzipped-archive shape. Unblocks persisting a
merged product, which was otherwise only an in-memory handle.
- `Orbis.GNSS.Data.fetch_merged_sp3_file/4` composes `fetch_merged_sp3/3` and
`write_sp3/3` into one call — fetch the merged current-day product from several
ultra-rapid centers and persist it to a standard SP3 file, returning
`{:ok, path, report}` so a live-latency product feeds the cache / observables /
positioning layers with no network at solve time.
- `Orbis.GNSS.RTK.solve_widelane_fixed_baseline_epochs/3` now supports
`partial_ambiguity_resolution: true`. When the full narrow-lane set fails the
ratio test, a bounded largest-first exhaustive subset search (run only after
the greedy ranking finds nothing) accepts the highest-ratio subset of the
largest size that passes the **unchanged** ratio threshold. Holding the
widelane integers fixed collapses the per-satellite bias, so the dual-frequency
partial fix safely covers a larger subset than the single-frequency partial —
on the real Wettzell arc, a 6-satellite fix (ratio 4.27, 4.4 cm baseline error)
versus the single-frequency 4. The full-set refusal and single-frequency
behavior are unchanged.
### Fixed
- `Orbis.GNSS.Data` now starts the Erlang `:ftp` transport itself before its
first FTP fetch (the GSSC/MGEX archives are FTP). A consumer that used Orbis
without starting the `:orbis` application tree (an escript, a bare script, a
release that did not start the dep) previously crashed with
`(EXIT) no process: :ftp_sup`; it no longer has to start Erlang transports by
hand.
- `Orbis.GNSS.SP3.merge/2` now treats equivalent IGS reference-frame
realizations as compatible: `IGS20` / `IGb20` / `IGc20` are the same
ITRF2020-based IGS frame (the middle letter is the product/realization line,
not a datum), so products labeled differently across centers merge instead of
failing with `{:incompatible_sources, "mismatched coordinate systems"}`. A
genuinely different datum (e.g. `IGS14` vs `IGS20`) is still rejected.
## [0.13.0] - 2026-06-08
### Added
- `Orbis.GNSS.Data.ops_ultra_sp3/3` and `ops_ultra_clk/3` add the ultra-rapid
precise-product tier to the offline-safe catalog/fetch layer. The catalog now
derives anonymous GSSC archive names and URLs for `IGS0OPSULT`, `COD0OPSULT`,
`ESA0OPSULT`, `GFZ0OPSULT`, and `GRG0OPSULT` SP3 products (plus `GRG0OPSULT`
clocks), including sub-daily issue times, `02D` spans, per-center sampling,
and latest-available issue fallback before a target epoch.
- `Orbis.GNSS.Data.fetch_merged_sp3/3` fetches the same SP3 product from several
centers in precedence order, tolerates not-yet-published or missing centers,
and returns one merged `Orbis.GNSS.SP3` plus provenance and merge-audit
metadata. One available center is returned as a flagged single-source result;
zero available centers returns `{:error, {:no_products, reasons}}`; centers
that cannot be combined (mismatched time scale / coordinate-system frame)
return `{:error, {:incompatible_sources, %{centers:, reason:}}}` rather than
leaking a raw merge error.
## [0.12.0] - 2026-06-08
### Added
- `Orbis.GNSS.SP3.merge/2` merges several SP3 products from different analysis
centers into one consistent precise-ephemeris dataset. Coverage is the union
across satellite×epoch (a satellite present in any input is present in the
output, filling a single center's dropouts); overlapping records are resolved
by robust consensus — the largest subset of centers agreeing within tolerance
is combined (`:mean`, `:median`, or `:precedence`), disagreeing centers are
recorded as outliers, and a cell with no agreeing subset is quarantined rather
than averaged. Pure and deterministic; returns the merged product plus an audit
report (`:quarantined`, `:single_source`, `:position_outliers`).
- `Orbis.GNSS.SP3.clock_reference_offset/3` and
`Orbis.GNSS.SP3.align_clock_reference/3` expose the clock-datum primitive:
precise clock products from different centers are referenced to different
station/ensemble clocks, so their raw clocks differ by a per-epoch common
offset. The first estimates that offset (robust median over common satellites);
the second returns a copy of a product with its clocks shifted onto a
reference's datum so the two are directly comparable. Positions need no such
treatment.
- `Orbis.GNSS.BroadcastComparison` now reports `clock_datum_removed_rms_m` /
`clock_datum_removed_max_m` alongside the raw clock statistics: the per-epoch
common reference-clock offset (median over satellites) is removed to give the
actual signal-in-space clock error, several times smaller than the raw value.
- `Orbis.GNSS.Ephemeris.sample/3` samples a precise (`Orbis.GNSS.SP3`) or
broadcast (`Orbis.GNSS.Broadcast`) ephemeris over an epoch window into a
unified per-satellite, per-epoch table of ECEF position and clock bias — the
same call shape for either source, with out-of-coverage cells reported as an
explicit `:no_ephemeris` gap rather than extrapolated.
- `Orbis.GNSS.Broadcast.position/3` evaluates a single satellite's broadcast
ECEF position and clock at an epoch (IS-GPS-200 LNAV, Galileo OS-SIS-ICD,
BeiDou BDS-SIS-ICD).
- `Orbis.GNSS.BroadcastComparison.compare/4` (and the `mix gnss.broadcast_diff`
task, with a `--system` selector) computes per-satellite broadcast-vs-precise
orbit and clock differences (3D plus radial/along/cross RMS and max) over a
window — the standard broadcast ephemeris accuracy check. Validated over a full
UTC day against the IGS combined broadcast (`BRDC00IGS`) and CODE MGEX final
precise orbits (`COD0MGXFIN`): GPS LNAV ~1.4 m, Galileo I/NAV ~0.9 m, BeiDou
~2.5 m orbit RMS.
- `Orbis.GNSS.RTK.solve_float_baseline_epochs/3` and fixed RTK solvers now
accept `code_smoothing: true` to apply per-receiver/per-ambiguity-arc Hatch
carrier smoothing to code observations before forming double differences.
The real Wettzell RTK gate verifies the smoothing reduces code residual RMS
while still refusing unsafe integer fixes.
- `Orbis.GNSS.RTK.solve_fixed_baseline_epochs/3` now supports opt-in partial
ambiguity resolution with `partial_ambiguity_resolution: true`. When the full
ambiguity set fails the ratio test, Orbis tries confidence-ranked subsets and
re-solves with the accepted subset fixed while rejected ambiguities remain
float-estimated. The real Wettzell RTK gate now verifies a safe four-ambiguity
partial fix improves the L1 baseline while the unsafe full-set fix remains
rejected.
### Changed
- GNSS integer ambiguity fixing now uses a complete bounded integer
least-squares scan over the caller's `integer_search_radius_cycles`, scored by
the exact ambiguity covariance inverse. Fixed-solution metadata reports
`integer_method: :bounded_ils` (or
`:widelane_narrowlane_bounded_ils`) for this path.
- The default integer candidate cap for precise positioning and RTK fixed
solvers is now `200_000`, enough for the default radius-1 search with up to 11
ambiguities.
- `Orbis.GNSS.RTK.solve_float_baseline_epochs/3` and fixed RTK solvers now use
non-reference satellites on the epochs where they are available instead of
dropping a satellite from the entire arc when it is absent from one epoch. The
reference satellite is still required across the arc.
### Fixed
- GNSS integer ambiguity fixing no longer treats a missing runner-up lattice
candidate as infinite ratio confidence; one-candidate searches now return
`integer_status: :not_fixed`.
- `Orbis.GNSS.SP3.position/3` (and everything built on it, including
`Orbis.GNSS.Observables` and the ephemeris sampler) now refuses an epoch
beyond the product's node coverage with an `epoch out of range` error instead
of silently extrapolating the interpolation spline to a non-physical position.
Queries within one sampling step of the ends still interpolate; in-coverage
results are bit-for-bit unchanged.
## [0.11.0] - 2026-06-08
### Added
- `Orbis.GNSS.PrecisePositioning.solve_fixed_epochs/3` now reports
`metadata.ambiguity_search` diagnostics (satellite order, float ambiguities,
ambiguity covariance, and inverse covariance in cycles) so callers can audit
the LAMBDA integer decision against the same lattice metric.
- `Orbis.GNSS.PrecisePositioning` now accepts `elevation_weighting: true` on
float, multi-epoch, and fixed solves, scaling code and phase row sigmas by
`1 / sin(elevation)` for a simple real-data stochastic model that down-weights
low-elevation observations.
- `Orbis.GNSS.RTK.double_differences/3` for deterministic base/rover
code-and-carrier double differences, the RTK measurement primitive that
cancels receiver clocks and common short-baseline satellite errors before
baseline estimation.
- `Orbis.GNSS.RTK.solve_float_baseline_epochs/3` for static float RTK baseline
estimation from supplied satellite ECEF positions and multi-epoch
code/carrier double differences, holding one float ambiguity per
non-reference double-difference arc. The float solution now exposes the
double-difference ambiguity covariance and inverse covariance in metres.
- `Orbis.GNSS.RTK.solve_fixed_baseline_epochs/3` for LAMBDA-fixed RTK baseline
estimation. It starts from the float RTK baseline, fixes double-difference
carrier ambiguities with the same correlated covariance used by the float
solve, and re-solves the baseline with those integers held fixed.
- `Orbis.GNSS.RTK.solve_fixed_baseline_epochs/3` now accepts
`ambiguity_offset_m`, so fixed RTK ambiguities can be modeled as
`offset + integer * wavelength`. This is the hook needed for
wide-lane-fixed / narrow-lane dual-frequency RTK workflows.
- `Orbis.GNSS.RTK.solve_widelane_fixed_baseline_epochs/3` for dual-frequency
RTK fixing. It estimates Melbourne-Wubbena wide-lane double-difference
integers, converts the arc to ionosphere-free narrow-lane measurements, then
runs the existing correlated LAMBDA baseline solve with the wide-lane offsets
held fixed.
- `Orbis.GNSS.RTK.solve_float_baseline_epochs/3` and
`solve_fixed_baseline_epochs/3` now understand carrier-phase arc identities:
map observations may carry `:ambiguity_id`, and LLI loss-of-lock can be
handled with `on_cycle_slip: :error | :drop_satellite | :split_arc`. Split
arcs reset the affected double-difference ambiguity while residuals keep the
physical satellite id.
- `Orbis.GNSS.RTK.solve_float_baseline_epochs/3` and
`solve_fixed_baseline_epochs/3` now accept `elevation_weighting: true`, which
scales each undifferenced measurement sigma by
`1 / max(sin(elevation), 0.05)` before propagating the correlated
double-difference covariance.
- `Orbis.GNSS.PrecisePositioning.solve_widelane_fixed_epochs/3` now supports
`on_cycle_slip: :split_arc`, which resets a satellite's carrier ambiguity at
detected cycle slips and keeps any post-slip fragments long enough for
wide-lane fixing. Split fragments are reported in
`metadata.split_cycle_slip_arcs` and use suffixed ambiguity ids such as
`"G21#2"` in `used_sats` and the ambiguity maps.
### Changed
- `Orbis.GNSS.PrecisePositioning.solve_fixed_epochs/3` now uses an
LDL-consistent forward recursion for the decorrelated LAMBDA sphere search.
This fixes the zero-candidate search miss on noisy real arcs without an
original-space substitute path: those arcs now return a `FixedSolution` with
`metadata.integer_status == :not_fixed` when candidates exist but fail the
ratio test.
- `Orbis.GNSS.RTK.solve_float_baseline_epochs/3` now propagates the
non-diagonal double-difference measurement covariance into the normal
equations and ambiguity covariance instead of treating DD rows that share a
reference satellite as independent.
- `Orbis.GNSS.RTK.solve_float_baseline_epochs/3` now chooses the
highest-average-elevation common satellite as the default reference, with a
deterministic satellite-id tie-break. `double_differences/3` still defaults to
the lexicographically first common satellite because it has no geometry.
## [0.10.0] - 2026-06-07
### Added
- `Orbis.GNSS.IonosphereFree.iono_free_phase/4` and
`iono_free_phase_cycles/4` for PPP/RTK-facing first-order ionosphere-free
carrier-phase combinations, plus `Orbis.GNSS.CarrierPhase.phase_meters/2`,
`code_minus_carrier/3`, and `smooth_iono_free_code/2` for code-carrier
diagnostics and dual-frequency divergence-free Hatch smoothing.
- `Orbis.GNSS.PrecisePositioning.solve_float/4`, a first float-ambiguity
carrier-phase estimator for one SP3-backed epoch from ionosphere-free code and
phase observations. It estimates receiver ECEF position, clock, and one float
ambiguity per satellite, exposing residuals and metadata for later PPP/RTK
layers.
- `Orbis.GNSS.PrecisePositioning.solve_float_epochs/3`, a static multi-epoch
float carrier-phase estimator that holds one ambiguity per satellite across an
arc while estimating one receiver clock per epoch. This is the bridge from
single-epoch float positioning toward PPP/RTK ambiguity fixing.
- `Orbis.GNSS.PrecisePositioning.solve_fixed_epochs/3`, an integer-fixed
multi-epoch carrier-phase estimator. It starts from the float arc, builds the
ambiguity covariance from the float normal matrix, runs LAMBDA integer
decorrelation plus a covariance-weighted integer sphere search on explicit
caller-supplied wavelengths, then re-solves receiver position and epoch clocks
with the selected ambiguities held fixed. The fixed solution reports the
integer method, ratio-test status, weighted scores, and evaluated candidate
count.
- `Orbis.GNSS.PrecisePositioning.solve_widelane_fixed_epochs/3`, a
dual-frequency convenience layer that fixes Melbourne-Wubbena wide-lane
integers first, then uses LAMBDA on the remaining narrow-lane integer while
returning both ambiguity sets.
- `Orbis.GNSS.PrecisePositioning` can now apply an opt-in a-priori
Saastamoinen/Niell tropospheric slant delay to ionosphere-free code and phase
observations (`troposphere: true` with surface meteorology options), including
the float, multi-epoch, and fixed-ambiguity solve paths.
- `Orbis.GNSS.PrecisePositioning.solve_float_epochs/3` and
`solve_fixed_epochs/3` can now estimate one residual zenith troposphere delay
over a static arc (`estimate_ztd: true`, with `troposphere: true`), reporting
`ztd_residual_m` and `metadata.ztd_estimated`.
- `Orbis.GNSS.PrecisePositioning.solve_widelane_fixed_epochs/3` accepts
`on_cycle_slip: :drop_satellite` to remove slipped satellite arcs before the
wide-lane / narrow-lane solve. The default remains `:error`; dropped satellites
are reported in `metadata.dropped_cycle_slip_sats`.
### Changed
- `Req` is now a required dependency. Network-backed features (`CelesTrak`,
`Orbis.GNSS.Data`, NAVCEN constellation status) are first-class Orbis
capabilities, and making the HTTP client required keeps consumer compiles
warning-free.
- The LAMBDA integer search now shrinks its live search bound to the current
second-best candidate, so `solve_fixed_epochs/3` keeps the same integer
decision and ratio-test semantics while visiting far fewer complete
candidates.
- `Orbis.GNSS.PrecisePositioning.solve_fixed_epochs/3` now reports an empty
LAMBDA sphere-search result as `{:error, {:no_integer_candidates, count}}`
instead of conflating it with the `:too_many_integer_candidates` cap.
## [0.9.2] - 2026-06-06
### Added
- `Orbis.GNSS.Constellation.diff/2` and `changed?/1` for deterministic
snapshot-to-snapshot catalog comparisons keyed by `{system, prn}`. The diff
reports added/removed PRNs plus NORAD, SP3 id, SVN, activity, and usability
changes in structured lists.
- GLONASS FDMA carrier-phase wavelengths. `Orbis.GNSS.RINEX.Observations`
exposes the parsed `GLONASS SLOT / FRQ #` channel map and `phases/3` now
derives carrier frequency, G1/G2 wavelengths, and metre phases for GLONASS
satellites with a channel entry, so `Orbis.GNSS.CarrierPhase` can process
real GLONASS phase arcs instead of skipping them.
- `Orbis.GNSS.ReducedOrbit` and `Orbis.GNSS.ReducedOrbit.Piecewise` can now fit
and drift against `%Orbis.Elements{}` TLE/OMM sources by sampling SGP4 over the
requested window (TEME → GCRS → ECEF, UTC scale). This closes the LEO reduced
orbit source path without changing the Rust reduced-orbit numerics.
## [0.9.1] - 2026-06-05
### Added
- Rustler precompiled-NIF packaging support. Release tags now build GitHub
Release archives for common Linux/macOS/Windows targets, and the Hex package
will include `checksum-*.exs` so supported users do not need a local Rust
toolchain. If no checksum file is present, Orbis source-builds instead of
trying to download missing assets; `ORBIS_BUILD=1` remains the explicit
source-build escape hatch.
- **`Orbis.GNSS.CarrierPhase`** — dual-frequency carrier-phase combinations and
the quality tooling on them: geometry-free (`L1 - L2`), wide-lane wavelength,
narrow-lane code, Melbourne-Wübbena, arc-wise cycle-slip detection (LLI bit,
geometry-free step, and Melbourne-Wübbena step, with documented thresholds),
and the single-frequency Hatch carrier-smoothed code (with slip/LLI reset).
GPS/Galileo/BeiDou; GLONASS satellites are skipped (FDMA wavelengths not yet
derived). Builds on the newly exposed phase observations; no crate change.
- `Orbis.GNSS.RINEX.Observations.values/3` and `phases/3` — expose the raw RINEX
observations for an epoch (pseudorange, carrier phase, Doppler, signal strength
with their LLI/SSI), and a carrier-phase convenience that adds the wavelength
and the phase in metres for GPS/Galileo/BeiDou bands (`band_frequency_hz/2` is
public; GLONASS FDMA wavelengths are not yet derived). `values/3` takes a
`:codes` per-system filter so only the requested systems/codes cross the NIF
boundary. This unlocks carrier-phase combinations without a parser change.
- `Orbis.GNSS.Constellation.validate_sp3!/2` — a build-time validation gate that
returns `:ok` or raises `ArgumentError` describing the findings (e.g. a
stale-active PRN that is active and usable in the catalog but missing from a
current SP3 product). Intended for catalog-build automation, not the runtime.
- Python/georinex/scipy oracle gates for the recent Orbis-only GNSS layer:
raw RINEX `values/3` / `phases/3`, `CarrierPhase` combinations/slip/Hatch
smoothing, `IonosphereFree` coefficients and combinations, `GNSS.QC`
weighting/chi-square thresholds, `GNSS.Observables.predict/5`, C/A
code/correlation/acquisition, LNAV parity/subframe synthesis,
visibility/DOP, velocity, DGNSS, `SolutionReport`, and `ReducedOrbit` /
`ReducedOrbit.Piecewise` fit/evaluation/drift against Astropy/scipy.
### Changed
- `Orbis.GNSS.Constellation.to_csv/2` gains a `:booleans` option: `:lower`
(default, conventional `true`/`false`) or `:title` (`True`/`False`, for a
pandas-style consumer that reads the `active` column as Python booleans).
- `Orbis.GNSS.QC.chi2_inv/2` now inverts the regularized-gamma chi-square CDF
and is checked against `scipy.stats.chi2.ppf`, replacing the older
Wilson-Hilferty approximation.
## [0.9.0] - 2026-06-05
A large GNSS expansion — signal generation, measurement modelling, velocity,
quality control, and differential positioning — alongside a consolidation of
the whole GNSS surface under the `Orbis.GNSS.*` namespace.
### Added
- **`Orbis.GNSS.Signal.CA`** — GPS L1 C/A Gold-code generation, chip indexing,
and auto/cross-correlation (IS-GPS-200 G1/G2 generators and per-PRN taps).
- **`Orbis.GNSS.Signal.Correlator`** — C/A code+carrier replica, coherent
correlation, a 2-D code-phase/Doppler acquisition search, and the
coherent-integration (sinc²) loss model.
- **`Orbis.GNSS.Navigation.LNAV`** — GPS LNAV subframe synthesis and decoding:
TLM/HOW, time-of-week, subframe parity (IS-GPS-200 Table 20-XIV), and
ephemeris bit-packing.
- **`Orbis.GNSS.Observables`** — predicted geometric range, range-rate, Doppler,
satellite clock, elevation, and azimuth from a receiver position and an SP3
ephemeris, with light-time (transmit-time) and Sagnac corrections.
- **`Orbis.GNSS.Geometry`** — satellite visibility above an elevation mask,
dilution of precision (GDOP/PDOP/HDOP/VDOP/TDOP), DOP/visibility time series,
and rise/set passes.
- **`Orbis.GNSS.Velocity`** — receiver velocity and clock drift from Doppler or
pseudorange-rate measurements by least squares over the line-of-sight geometry.
- **`Orbis.GNSS.QC`** — measurement quality control: residual-based RAIM fault
detection, leave-one-out fault detection and exclusion (FDE), and
elevation/C-N₀ measurement weighting.
- **`Orbis.GNSS.IonosphereFree`** — the dual-frequency ionosphere-free
pseudorange combination, with standard per-system frequency pairs
(GPS L1/L2, Galileo E1/E5a, BeiDou B1I/B3I).
- **`Orbis.GNSS.DGNSS`** — code-differential positioning: base-station
pseudorange corrections and corrected rover solves that cancel the errors
common to both receivers (satellite clock, ephemeris, short-baseline
atmosphere).
- **`Orbis.GNSS.SolutionReport`** — a per-satellite and summary diagnostic over
a position solution: elevation/azimuth, post-fit and RAIM-normalized
residuals, DOP, residual RMS, and the integrity verdict.
- **`Orbis.GNSS.ReducedOrbit.Piecewise`** — a piecewise (segmented)
reduced-orbit model that tiles a span into contiguous fitted segments for
tighter caching/transport accuracy than a single mean-element fit.
### Changed
- **Breaking:** GNSS modules now live under the `Orbis.GNSS.*` namespace. The
old top-level GNSS names (`Orbis.SP3`, `Orbis.PointPositioning`,
`Orbis.GnssData`, etc.) were removed instead of retained as aliases, matching
the library's current single-client / pre-broad-adoption status. Examples:
`Orbis.GNSS.SP3`, `Orbis.GNSS.Positioning`, `Orbis.GNSS.Data`,
`Orbis.GNSS.RINEX.Observations`, `Orbis.GNSS.ReducedOrbit`,
`Orbis.GNSS.Signal.CA`, and `Orbis.GNSS.Navigation.LNAV`.
- Internal GNSS implementation helpers were consolidated under
`Orbis.GNSS.Core` for shared constants, ECEF input normalization,
epoch/window handling, validation, source sampling, and versioned-map guards.
- Hardened public-API input validation across the GNSS modules: malformed
receiver/base positions, out-of-range RAIM options, sub-second piecewise
segment lengths, out-of-range LNAV flags, and duplicate observations now
return tagged errors (or raise a clear `ArgumentError` for invalid options)
instead of crashing, looping, or silently truncating.
## [0.8.0] - 2026-06-05
Observation parsing and a compact orbit model. Orbis can now read a station's
RINEX observation file end-to-end into pseudoranges, and distill a position
track into a tiny, transportable mean-element model.
### Added
- **`Orbis.GNSS.RINEX.Observations`** — RINEX 3 observation parsing with Hatanaka (CRINEX 1.0
and 3.0) decoding. Decodes `.crx`/`.rnx`, exposes the header (incl. the
surveyed `APPROX POSITION`), observation codes, and epochs, and extracts
single-frequency pseudoranges (`pseudoranges/3`) in the
`[{satellite_id, range_m}]` shape `Orbis.GNSS.Positioning.solve/4` consumes —
closing the loop from a station's observation file to a recovered position.
`Orbis.GNSS.Data` gains a station observation product fetch and an
`observations/2` loader. CRINEX decoding is verified byte-for-byte against
`crx2rnx`; an end-to-end test recovers a surveyed station position to metre
level from real GPS observations.
- **`Orbis.GNSS.ReducedOrbit`** — a compact, fitted mean-element approximation of an
orbit for caching, transport, and quick visibility math (not orbit
determination). Fits from an `Orbis.GNSS.SP3` track or a list of ECEF samples;
evaluates position/velocity (ECEF by default, GCRS on request); reports a
source-backed `drift/3` against the source ephemeris; and serialises to a
stable, versioned map (`to_map/1`/`from_map/1`). Two models: `:circular_secular`
(default) and `:eccentric_secular` (nonsingular `h = e·sin ω`, `k = e·cos ω`),
the latter recovering the radial `a·e` signal that the circular model discards —
cutting full-day extrapolation error by one-to-three orders of magnitude for
GPS and BeiDou while matching the circular model on near-circular Galileo.
## [0.7.0] - 2026-06-04
GNSS positioning. Orbis can now recover a receiver position from pseudoranges
against precise or broadcast ephemeris, with the supporting ephemeris,
correction, time, and data-fetch layers.
### Added
- **`Orbis.GNSS.Positioning`** — single-point positioning (SPP). Solves a
receiver position, clock, and geometry diagnostics from one epoch of
pseudoranges against either an `Orbis.GNSS.SP3` precise product or an
`Orbis.GNSS.Broadcast` handle. Multi-constellation
(GPS / Galileo / BeiDou / GLONASS) solves carry one receiver clock per system;
the solution reports position, geodetic position, per-system clocks, DOP,
residuals, used/rejected satellites, and solver metadata.
- **`Orbis.GNSS.SP3`** — SP3-c/SP3-d precise orbit/clock loading and arbitrary-epoch
satellite position/clock interpolation, plus `satellite_ids/1` to read the
product's declared satellite set.
- **`Orbis.GNSS.Constellation`** — a GPS constellation catalog built from
CelesTrak `gps-ops` OMM identity and an optional NAVCEN status/SVN overlay
(PRN ↔ SVN ↔ NORAD ↔ SP3 id, active/usable flags). Merges sources only when
the block type matches, recording PRN-transition disagreements as conflicts
rather than corrupting identity; exports the compact mapping CSV and validates
a catalog (duplicate PRNs/NORAD ids, inactive/unusable PRNs, and missing/extra
satellites against a loaded `Orbis.GNSS.SP3` product).
- **`Orbis.GNSS.Broadcast`** — RINEX 3.x and 4.xx navigation parsing and
broadcast orbit/clock evaluation: GPS LNAV, Galileo I/NAV and F/NAV, BeiDou
D1/D2 (including geostationary satellites), and GLONASS (PZ-90.11 state-vector
propagation by Runge–Kutta integration).
- **`Orbis.GNSS.Ionosphere`** (broadcast Klobuchar, frequency-aware across L1/E1/B1I)
and **`Orbis.GNSS.Troposphere`** (Saastamoinen zenith delay + Niell mapping)
correction models.
- **`Orbis.GNSS.Data`** — an optional product fetch/cache layer: a catalog over
public archives, HTTPS (`Req`) and FTP downloads, an atomic on-disk cache with
SHA-256 integrity and provenance sidecars, a gzip-bomb guard, and an offline
mode. Includes convenience loaders that return `Orbis.GNSS.SP3` /
`Orbis.GNSS.Broadcast` handles. `Req` is an optional dependency.
- **`Orbis.GNSS.Time`** — GNSS epoch/seconds-of-week and day-of-year helpers.
### Notes
- The GNSS numerical core lives in the Rust `astrodynamics` / `astrodynamics-gnss`
crate layer. Its libm-bound components (orbit and clock evaluation, ionosphere,
troposphere, dilution of precision) are held to bit-exact (0 ULP) parity
against pinned Python references; broadcast orbits are additionally validated
against precise SP3 products. The least-squares solver's final position is a
sub-micron solver-agreement result, not a 0-ULP claim.
---
Releases before 0.7.0 predate this changelog.