Ryan Malloy
a792e7e083
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
99 lines
3.6 KiB
Plaintext
99 lines
3.6 KiB
Plaintext
-- Test GiST index and operators (2-D: altitude + inclination)
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CREATE EXTENSION IF NOT EXISTS pg_orbit;
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NOTICE: extension "pg_orbit" already exists, skipping
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-- Create test table with mixed orbit types
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CREATE TABLE test_orbits (
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id serial,
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name text,
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tle tle
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);
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-- ISS (LEO, ~400km, inclination 51.64 deg)
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INSERT INTO test_orbits (name, tle) VALUES ('ISS',
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'1 25544U 98067A 24001.50000000 .00016717 00000-0 10270-3 0 9025
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2 25544 51.6400 208.9163 0006703 30.1694 61.7520 15.50100486 00001');
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-- Hubble (LEO, ~540km, inclination 28.47 deg)
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INSERT INTO test_orbits (name, tle) VALUES ('Hubble',
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'1 20580U 90037B 24001.50000000 .00000790 00000+0 39573-4 0 9992
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2 20580 28.4705 61.4398 0002797 317.3115 42.7577 15.09395228 00008');
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-- GPS IIR-M (MEO, ~20200km, inclination 55.44 deg)
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INSERT INTO test_orbits (name, tle) VALUES ('GPS-IIR',
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'1 28874U 05038A 24001.50000000 .00000012 00000+0 00000+0 0 9993
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2 28874 55.4408 300.3467 0117034 51.6543 309.5420 2.00557079 00006');
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-- Equatorial-LEO: same altitude as ISS but near-equatorial inclination (5 deg).
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-- Same mean motion (15.501 rev/day) and eccentricity as ISS → same altitude band.
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-- Different inclination → should NOT overlap with ISS under 2-D key.
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INSERT INTO test_orbits (name, tle) VALUES ('Equatorial-LEO',
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'1 99901U 24999A 24001.50000000 .00016717 00000-0 10270-3 0 9990
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2 99901 5.0000 208.9163 0006703 30.1694 61.7520 15.50100486 00001');
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-- Create GiST index
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CREATE INDEX test_orbits_gist ON test_orbits USING gist (tle);
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-- 2-D overlap: ISS && Equatorial-LEO should be false (same altitude, different inclination)
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SELECT a.name AS sat_a, b.name AS sat_b, a.tle && b.tle AS overlaps
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FROM test_orbits a, test_orbits b
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WHERE a.id < b.id
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ORDER BY a.name, b.name;
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sat_a | sat_b | overlaps
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---------+----------------+----------
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GPS-IIR | Equatorial-LEO | f
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Hubble | Equatorial-LEO | f
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Hubble | GPS-IIR | f
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ISS | Equatorial-LEO | f
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ISS | GPS-IIR | f
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ISS | Hubble | f
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(6 rows)
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-- Altitude distance: ISS <-> Equatorial-LEO should be ~0 (same altitude shell)
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SELECT a.name AS sat_a, b.name AS sat_b,
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round((a.tle <-> b.tle)::numeric, 0) AS alt_dist_km
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FROM test_orbits a, test_orbits b
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WHERE a.id < b.id
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ORDER BY a.name, b.name;
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sat_a | sat_b | alt_dist_km
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---------+----------------+-------------
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GPS-IIR | Equatorial-LEO | 19451
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Hubble | Equatorial-LEO | 115
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Hubble | GPS-IIR | 19332
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ISS | Equatorial-LEO | 0
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ISS | GPS-IIR | 19451
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ISS | Hubble | 115
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(6 rows)
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-- GiST index scan: find all sats overlapping ISS (altitude AND inclination)
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-- Should return only ISS itself (Equatorial-LEO is at same altitude but wrong inclination)
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SET enable_seqscan = off;
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SELECT name FROM test_orbits
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WHERE tle && (SELECT tle FROM test_orbits WHERE name = 'ISS')
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ORDER BY name;
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name
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------
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ISS
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(1 row)
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RESET enable_seqscan;
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-- Nearest-neighbor via GiST: order by altitude distance to ISS
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SET enable_seqscan = off;
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SELECT name, round((tle <-> (SELECT tle FROM test_orbits WHERE name = 'ISS'))::numeric, 0) AS dist
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FROM test_orbits
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WHERE name != 'ISS'
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ORDER BY tle <-> (SELECT tle FROM test_orbits WHERE name = 'ISS');
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name | dist
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----------------+-------
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Equatorial-LEO | 0
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Hubble | 115
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GPS-IIR | 19451
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(3 rows)
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RESET enable_seqscan;
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-- Self-overlap is always true
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SELECT name, tle && tle AS self_overlap FROM test_orbits ORDER BY name;
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name | self_overlap
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----------------+--------------
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Equatorial-LEO | t
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GPS-IIR | t
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Hubble | t
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ISS | t
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(4 rows)
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-- Cleanup
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DROP TABLE test_orbits;
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