Replace the sat_code git submodule (lib/sat_code/) with vendored
sources in src/sgp4/. The upstream .cpp files are renamed to .c —
the code is valid C99 with zero C++ features. This eliminates the
g++ and -lstdc++ build dependencies.
Adds 518 Vallado test vectors (AIAA 2006-6753-Rev1) as a 13th
regression suite to verify byte-identical numerical output.
Updates all documentation (CLAUDE.md, DESIGN.md, 11 MDX pages,
Dockerfile) to reflect the new layout and pure-C compilation.
Clean-room DE binary reader (~400 lines C) with Chebyshev/Clenshaw
evaluation — no GPL dependency on jpl_eph. Per-backend lazy
initialization preserves PARALLEL SAFE. Existing VSOP87/ELP82B
functions stay IMMUTABLE; new _de() variants are STABLE with
automatic fallback to compiled-in ephemerides on any DE failure.
Implementation:
- de_reader.c: header parse, record seek, Clenshaw recurrence
- eph_provider.c: GUC (pg_orbit.ephemeris_path), lazy init,
ICRS-to-ecliptic frame rotation, on_proc_exit cleanup
- de_funcs.c: 11 new SQL functions (_de variants + diagnostics)
- Constant chain of custody rules 6-8 (frame rotation,
same-provider, AU consistency)
Extract observe_from_geocentric() to astro_math.h for shared use
by planet_funcs.c, moon_funcs.c, and de_funcs.c.
57 → 68 functions, 11 → 12 regression test suites, all passing.
Add Universal Variable Lambert solver for computing transfer orbits
between any two planets. Enables pork chop plot generation as SQL:
SELECT dep_date, arr_date, lambert_c3(3, 4, dep_date, arr_date)
FROM generate_series(...) dep CROSS JOIN generate_series(...) arr;
New functions:
- lambert_transfer(dep_body, arr_body, dep_time, arr_time) → RECORD
Returns C3 departure/arrival (km^2/s^2), v_infinity (km/s),
time of flight (days), and transfer orbit SMA (AU).
- lambert_c3(dep_body, arr_body, dep_time, arr_time) → float8
Convenience: departure C3 only, NULL on solver failure.
The solver uses Stumpff functions for unified elliptic/parabolic/hyperbolic
handling, with Newton-Raphson iteration and bisection fallback.
Each solve is sub-millisecond; PARALLEL SAFE for batch computation.
All 11 regression tests pass.
Add observation functions for 19 planetary moons across four systems:
- Galilean moons (Io, Europa, Ganymede, Callisto) via clean-room L1.2 theory
- Saturn moons (Mimas through Hyperion) via TASS 1.7
- Uranus moons (Miranda through Oberon) via GUST86
- Mars moons (Phobos, Deimos) via MarsSat
Add Jupiter decametric radio burst prediction for Radio JOVE operators:
- io_phase_angle() — Io orbital phase from superior conjunction
- jupiter_cml() — System III Central Meridian Longitude with light-time correction
- jupiter_burst_probability() — Carr et al. (1983) source regions A, B, C, D
L1.2 Galilean theory is a clean-room MIT implementation from the published
IMCCE FORTRAN coefficients. All other ephemeris libraries are MIT-licensed
extractions from Stellarium with static caching removed for PARALLEL SAFE.
All 10 regression tests pass. Extension .so grows from 2.4MB to 2.5MB.
Phase 1 — Stars, comets, Keplerian propagation:
- star_observe() / star_observe_safe(): fixed star alt/az via IAU 1976
precession, equatorial-to-horizontal transform
- kepler_propagate(): two-body Keplerian orbit propagation for
elliptic, parabolic, and hyperbolic orbits
- comet_observe(): observe comets/asteroids from orbital elements
- heliocentric type: ecliptic J2000 position (x, y, z in AU)
Phase 2 — VSOP87 planets, ELP82B Moon, Sun:
- planet_heliocentric(): VSOP87 heliocentric ecliptic J2000 positions
for Mercury through Neptune (Bretagnon & Francou, MIT)
- planet_observe(): full observation pipeline for any planet
- sun_observe(): Sun position from negated Earth VSOP87
- moon_observe(): ELP2000-82B lunar position (Chapront-Touzé, MIT)
- Clean-room precession (IAU 2006) and sidereal time (IERS 2010)
- elliptic_to_rectangular utility (Stellarium, MIT)
All Stellarium extractions are MIT-licensed, thread-safe (static
caching removed for PARALLEL SAFE), zero external data files.
All 9 regression tests pass (90ms total).
The 1-D altitude-band index only pruned ~25% of the 22k satellite
catalog (eliminates MEO/GEO/HEO but 75% is LEO). Adding inclination
as a second indexed dimension prunes an additional ~40% of remaining
candidates — objects in equatorial or low-inclination orbits that
geometrically cannot pass over the observer's latitude.
Key changes:
- tle_alt_range (16 bytes) → tle_orbital_key (32 bytes) with
inc_low/inc_high fields
- All 8 GiST support functions updated for 2-D bounding boxes
- Penalty uses margin (half-perimeter) not area to avoid degeneracy
when leaf entries have zero-width inclination ranges
- Picksplit selects split dimension by normalized spread
- && operator now checks altitude AND inclination overlap
- <-> operator remains altitude-only (conjunction screening is
altitude-dominant)
- SQL operator comments updated for 2-D semantics
- Test adds Equatorial-LEO satellite at ISS altitude but 5° inclination
to validate inclination-based pruning
Implements 5 new C functions requested by the Craft (Astrolock) API team:
- tle_from_lines(text, text): two-argument TLE constructor
- observer_from_geodetic(float8, float8, float8): numeric observer constructor
- observe(tle, observer, timestamptz): single-call propagate + topocentric
- sgp4_propagate_safe(tle, timestamptz): returns NULL on propagation error
- observe_safe(tle, observer, timestamptz): returns NULL on propagation error
Refactors do_propagate() into safe/unsafe variants to support NULL returns.
Adds regression test (convenience.sql) covering all new functions including
an equivalence test verifying observe() matches the manual two-step pipeline.
All 6 regression tests pass.
6 custom types (tle, eci_position, geodetic, topocentric, observer,
pass_event), 67 SQL functions, 2 operators (&&, <->), and a GiST
operator class for altitude-band indexing. Wraps Bill Gray's sat_code
for SGP4/SDP4 propagation with WGS-72 constants for propagation and
WGS-84 for coordinate output. All 5 regression tests pass on PG 18.
