广播星历参数拟合算法研究

导航卫星一般采用近圆轨道,当卫星轨道偏心率或者轨道倾角接近于0时,利用GPS卫星开普勒轨道根数拟合卫星广播星历会出现一些问题。当高轨卫星轨道偏心率接近0时,广播星历拟合精度下降甚至拟合失败,为此本文提出了减少拟合参数个数、固定轨道根数M0或者延长星历参数拟合弧段长度的方法;针对GEO卫星在小倾角情况下,广播星历可能拟合失败的情况,本文提出了改变坐标系参考轨道面,在新的坐标系下拟合广播星历的方法。结果表明,改进后的拟合方法能适用于各种类型的导航卫星轨道,拟合精度在cm级或者mm级。

The research of satellites broadcast ephemeris parameters fitting arithmetic

Nearly circular orbit satellites are often adopted in satellite navigation constellation. When their orbit eccentricity or inclination are near zero, some problems may occur when the GPS Kepler orbit elements fitting method is applied to fit broadcast ephemeris parameters. When the eccentricity of high orbit satellite is near zero, the fitting broadcast ephemeris parameters may lead to bad accuracy, even to failure. An improved method, less fitting parameters with fixed M0 or increased orbit arc lengths, is introduced for this problem. For GEO with near zero inclination, the GPS broadcast ephemeris parameters fitting may be unsuccessful. But the Kepler orbit parameters fitting method will works well in a new reference frame with different reference plane. The results show that these methods are adapted well to all types of navigation satellite, and the error of the fitting ephemeris is less than several centimeters, even several millimeters.