A NodeJS port of python-sgp4 used for predicting and calculating orbital information of satellites from TLE data.

SGP4/SDP4 calculation library

High-performance SGP4 GPU/WebGPU/WebGL WASM wrapper.

Toolkit for solar system ephemerides and satellite propagation via SGP4

Orbital Object Toolkit. A modern typed replacement for satellite.js including SGP4 propagation, TLE parsing, Sun and Moon calculations, and more.

太陽系エフェメリス（JPL近似軌道要素1800-2050・Schlyter月理論・IAU自転）＋共通の時計（ephem/clock・#42）＋人工衛星 SGP4/SDP4（ephem/sgp4）。ortho-solar と ortho-japan の共用臓器

WebAssembly / JavaScript interface over the sidereon GNSS + astrodynamics engine: SP3 loading and multi-product merge, SPP / RTK (float + fixed) / PPP (float + fixed) positioning, IONEX slant delay, SGP4 and numerical orbit propagation, RINEX observation/

Real-time satellite tracking (ISS, GPS, weather, military) using CelesTrak TLE data and SGP4 propagation.

EarthOS satellites layer: CelesTrak GP catalog propagated with SGP4 in workers (Starlink, ISS, GPS, active catalog)

High-performance SGP4 orbital propagator for 50K+ satellites in Web Worker (WASM)

Modular set of functions for SGP4 and SDP4 propagation of TLEs.

This project is designed to visualize the orbits of spacecraft based on the SGP4/SDP4 ballistic models, in order to modify the ballistic parameters and evaluate the changes displayed on the Canvas using the ThreeJS library.

Open, reproducible PNT-resilience simulator with quantum-sensor performance models

Satellite TLE tools in JavaScript.

Standalone StateProviders for Argelander: near-earth SGP4/TLE and pre-sampled state playback behind the frozen SPEC-PROVIDER seam, with worker port marshalling. Reserved pre-release.

javascript port of predict open-source satellite tracking library

Two-line element set (TLE) data format parser

Satellite positions, passes and visibility from orbital elements, in TypeScript, checked against Skyfield

Mars3D平台插件, 卫星及相关视锥体可视化功能

EarthOS geodesy, orbital transforms, astronomy, and spatial indexing