3 Commits

Author SHA1 Message Date
70420c3b4f Phase 4: Lambert transfer orbit solver for interplanetary trajectories
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.
2026-02-16 02:00:09 -07:00
ad7209d0db Phase 3: Planetary moons and Jupiter radio burst prediction
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.
2026-02-16 01:55:13 -07:00
0544a78276 pg_orbit 0.2.0: Full solar system computation at the SQL layer
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).
2026-02-16 01:36:27 -07:00