Hybrid SGP4 orbit propagator

Construction of a BDSPHERE solar radiation pressure model for BeiDou GEOs at vernal and autumn equinox periods

In this project, an algorithm has been proposed to detect a satellite’s maneuver by comparingthe orbital elements observed from the two line element data and the orbital elements propagatedwith the ...

Combined Heuristic and Statistical Methodologies applied to Maneuver Detection in the SST Observation Correlation Process

The precision of BDS navigation message based on global satellite laser ranging (SLR) analysis is about 60 cm for geostationary earth orbit (GEO) satellites. There is an obvious gap between the POD accuracy of GEO satellites and IGSO & MEO satellites. The reason being that the GEO satellites lie in high and geostationary orbits. Also, the mature GPS solar radiation pressure (SRP) model is used as a reference in orbit determination for GEO satellite. We uses traditional spherical SRP model as background model and estimates the SRP parameters of a 2-yr precise GEO satellite ephemeris with dynamic smoothing method, and builds a continuous SRP parameter sequence. Thoughts on “Fourier series overlaid linear term” modeling are proposed and an empirical SRP model for BDS GEO satellite (BDSPHERE for short) comes into being. We verify the model based on observation data and the results show that: (1) the signal-in-space range error (SISRE(ORB)) of GEOs based on BDSPHERE model amounts to 0.63 m, while the orbital SISRE(ORB) for 8 h, 12 h and 24 h prediction is 0.79 m, 1.24 m and 1.65 m respectively; (2) compared to traditional spherical SRP model, there is an increase of 56.55%, 65.81%, 63.31% and 58.33% with the BDSPHERE model. The precision of radial orbit by global SLR analysis is 0.597 m, an increase of 70.06%.

A BDSPHERE Solar Radiation Pressure Model for BDS GEO Satellites

For sub-meter precise orbit determination of GEO satellites, solar radiation pressure (SRP) perturbation is the major error and also the main factor that restrains the accuracy of orbit prediction. Compared with MEO satellites, GEO satellites are easier to be influenced by SRP perturbation due to their high altitude orbit feature and the magnitude achieves 10–7 (relative to the central gravity). Solar pressure modeling relates to multiple factors, including the satellite platform, attitude controlling, etc., thus it is difficult to accurately model it. It is also the biggest error term that affects the accuracy of precise orbit determination (POD) for medium and high Earth orbit satellites. This paper completes the construction of the time series of the 3.5-year model SRP using the recent 3.5-year real data from COMPASS using the post-processing method. Meanwhile, this paper discovers a secular variation trend and a half-year period of the Cr coefficient. The parameters variation features relating to the seasonal solar activities are investigated. Estimated SPR parameters and periods of solar activities are analyzed, as well as the relationship among the POD accuracy. Therefore, some fruitful conclusions have been got, which helps to establish and refine the COMPASS GEO SRP model.

Zhi Qiao Chang

Papers

Application Characteristics Analysis of the T20 Solar Radiation Pressure Model in Orbit Determination for COMPASS GEO Satellites