Orbital data tooling · NEOGY LLC

On 11 July 2026 the satellite catalog passed 99,999 objects, the most a TLE's five-digit field can hold; provider data now carries six-digit, nine-digit and lettered (Alpha-5) catalog numbers, and libraries reading them may not expect these forms. gp-omm-conformance is a test corpus for that migration: seventeen cases built from real CelesTrak data with no invented element sets, a runner, and adapters for testing your own parser.

Each run by hand against all seventeen cases on 2026-09-24, at the version named, and every finding reproduced on the library's own code before it was reported. These are results against a specific version on a specific date, not verdicts on the projects; six of the eight read only TLE, and CelesTrak's TLE feed omits the objects that trigger these failures, so their users are not affected today.

PyEphem 4.2.1 — #296
Five-digit sets exact, epoch within a microsecond.
Alpha-5 fields read as catalog number 0, silently.

satellite.js 7.1.0 — #185
All 604 TLE records exact, nine-digit OMM ids accepted.
OMM JSON epochs truncated to milliseconds; the TLE catalog field left as a string.

Gpredict 2.6 — #426
Five-digit ids right, every element but one exact.
Alpha-5 fields become 0; the mean motion loses its last digit on every record.

gods-eye-view main ce671ce — #751
Five-digit ids right, 1998 epoch pivots.
Alpha-5 satellites collapse onto one entry keyed NaN; the rest dropped.

SatDump 1.2.2 and master — #1221
Five-digit sets exact, six-digit CSV ids on master.
Alpha-5 sets dropped silently; SupGP CSV rejected whole on master.

libsgp4 master and PR #42 — #45, PR #42
Five-digit sets exact but for an 8 µs epoch rounding, CSV takes six-digit ids.
Master refuses every Alpha-5 set; the PR's letter table drops X and shifts Y and Z.

tle.js 5.0.3 — #62
Five-digit sets exact, checksums count letters as 0.
Alpha-5 fields give NaN with no error; two-digit years pivot at 50.

astroz main d558933 — #97, #98
Carried elements exact, nine-digit JSON ids as integers.
Alpha-5 decoded without skipping I and O; public epoch field off by hundreds of days.

• One fix merged upstream: python-sgp4 PR #172, the empty OBJECT_ID in OMM XML, merged 2026-09-24 and not yet in a release.
• Eleven reports filed with ten projects, the eight above plus python-sgp4 and strf, astroz accounting for two, each stating what was run and how to reproduce it.
• Corpus v0.2.1 archived on Zenodo: concept DOI 10.5281/zenodo.22867654, version DOI 10.5281/zenodo.22926017.

git clone https://github.com/hneogy/gp-omm-conformance.git && cd gp-omm-conformance
python3 tools/fetch.py                                              # once; fetches the fixtures under CelesTrak's usage policy
python3 -m gpconf run --adapter tests.adapters.reference:Parser    # the control
python3 -m gpconf run --adapter mypkg.gpconf_adapter:Parser --json report.json   # your parser

NEOGY LLC, orbital data tooling. Results and a live tracker at gpconf.neogy.dev · the corpus · neogy.dev