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
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.
