Third-party notices
Octant is mostly other people's work. Everything below is used under its own terms, which
this file records rather than summarises — where a licence requires attribution, that
attribution also appears in the application itself.
Octant's own terms are in LICENSE.md.
Software
| Component | Licence | Use |
| Orekit 13.1.7 | Apache-2.0 | All orbit propagation, frames, time scales and geodesy |
| Hipparchus 4.0.3 | Apache-2.0 | Numerics under Orekit |
| CesiumJS 1.144 | Apache-2.0 | 3D globe rendering |
| TeaVM 0.15.0 | Apache-2.0 | Compiles Orekit to JavaScript |
| GMAT R2026a | Apache-2.0 | Validation reference (development only, not distributed) |
Modifications
Two dependencies are patched to run under TeaVM. Both are Apache-2.0, which permits
modification provided it is stated — so, stated:
- Hipparchus
org.hipparchus.exception.Localizable— message translation removed;
it required a ResourceBundle overload TeaVM does not implement.
org.hipparchus.util.MathArrays — multi-dimensional array allocation rewritten as
nested single-dimension allocation, which TeaVM does implement.
- Orekit
org.orekit.utils.IERSConventions— resource loading routed through an added
org.orekit.data.BakedResources registry, because TeaVM does not bundle classpath
resources. Inert on a JVM.
Both patches are reproducible from benchmark/scripts/patch-hipparchus.sh and
benchmark/scripts/patch-orekit.sh. Neither changes any physics.
Data
| Source | Terms | Use |
| Natural Earth vector | Public domain | Coastlines, national borders, populated places |
| Natural Earth II raster (bundled in CesiumJS) | Public domain | Offline base imagery |
| NASA EOSDIS GIBS | Public domain, no API key | Blue Marble, VIIRS true colour, VIIRS city lights |
| NASA Trek — LRO WAC, Viking MDIM 2.1 | Public domain | Moon and Mars imagery, on the globe and as the 2D map’s surface. Credit: NASA/GSFC/ASU; NASA/JPL/USGS |
| ICGEM GL0660B (GRGM660PRIM) | Freely distributed for scientific use | Lunar gravity field |
| ICGEM jgm85f01 | Freely distributed for scientific use | Mars gravity field |
| ICGEM EIGEN-6S (GFZ/GRGS) | Freely distributed for scientific use | Earth gravity field |
| JPL DE440 planetary ephemeris | Public domain (NASA/JPL-Caltech) | Positions of the Moon and planets. Trimmed here to 1950–2050 and fetched only when a scenario needs another body |
| Orekit data | Various, per file | Leap seconds, Earth orientation, atmosphere |
| IERS conventions tables (bundled in Orekit) | IERS terms | Precession, nutation, frame transformations |
Gravity models are redistributed trimmed to degree and order 20; the originals are far
larger and unmodified copies are available from ICGEM.
To verify before commercial release
- [ ] ICGEM redistribution terms for GL0660B, jgm85f01 and EIGEN-6S — "free for scientific
use" is not automatically "free to redistribute inside a commercial product". Confirm
per model, and fall back to fetching them at runtime if redistribution is restricted.
- [ ] Celestrak usage policy — cleared in
principle, but re-read before shipping any TLE ingest.
- [ ] Confirm no GPL or AGPL component has entered the dependency graph. **JSatOrb is
AGPLv3 and was deliberately not used, read, or derived from** — see
docs/PRODUCT.md §2.