发明名称 |
GNSS ephemeris with graceful degradation and measurement fusion |
摘要 |
A method for providing an extended propagation ephemeris model for a satellite in Earth orbit, the method includes obtaining a satellite's orbital position over a first period of time, applying a least square estimation filter to determine coefficients defining osculating Keplarian orbital elements and harmonic perturbation parameters associated with a coordinate system defining an extended propagation ephemeris model that can be used to estimate the satellite's position during the first period, wherein the osculating Keplarian orbital elements include semi-major axis of the satellite (a), eccentricity of the satellite (e), inclination of the satellite (i), right ascension of ascending node of the satellite (Ω), true anomaly (θ*), and argument of periapsis (ω), applying the least square estimation filter to determine a dominant frequency of the true anomaly, and applying a Fourier transform to determine dominant frequencies of the harmonic perturbation parameters. |
申请公布号 |
US9075140(B2) |
申请公布日期 |
2015.07.07 |
申请号 |
US201012889351 |
申请日期 |
2010.09.23 |
申请人 |
Purdue Research Foundation |
发明人 |
Garrison James Levi;Walker Michael Allen |
分类号 |
G01C21/24;G01S19/27 |
主分类号 |
G01C21/24 |
代理机构 |
Maginot, Moore & Beck LLP |
代理人 |
Maginot, Moore & Beck LLP |
主权项 |
1. A method for providing an extended propagation ephemeris model for a satellite in Earth orbit comprising:
obtaining within a ground station data associated with a satellite's orbital position over a first period of time; calculating within the ground station, from the data, coefficients defining osculating Keplarian orbital elements and harmonic perturbation parameters associated with a coordinate system defining an extended propagation ephemeris model that can be used to estimate the satellite's position during the first period; applying a Fourier transform to data derived from the calculated coefficients to determine dominant frequencies of the harmonic perturbation parameters; weighting the extended propagation ephemeris model according to a weighing function so that the extended propagation ephemeris model generates a highest level of accuracy at a beginning of the first period; and providing the weighted extended propagation ephemeris to a receiver. |
地址 |
West Lafayette IN US |