Low-order surface model-based satellite clock and ephemeris error relative correction method

Abstract

The invention discloses a low-order surface model-based satellite clock and ephemeris error relative correction method. The method includes the following steps that: satellite clock errors are corrected in a one-stop manner; 6 kinds of low-order surface models are built for relatively residual ephemeris errors; a surface model with a minimum visual-direction residual error is found out; surface model parameters are obtained through more than 6 differential stations; a relatively residual ephemeris error of a site is calculated through using the surface model parameters; and a correction effect can be obtained through optimizing the layout of 11 differential stations. According to the method adopted, strict time synchronization networks are not required to be built between the differential stations; and a visual-direction residual error in a service cell can be the corrected to a very small range through the differencing of the 11 stations, and therefore, positioning accuracy is high.

Description

technical field [0001] The invention belongs to the field of satellite navigation, in particular to a method for relative correction of star clock and ephemeris errors based on a low-order surface model Background technique [0002] The traditional wide-area difference method uses the full state estimation method to estimate the error of the star clock and ephemeris, assuming that the system time of each station and the satellite navigation system is completely synchronized, the full state estimation method uses the satellite position and time to form a 4-dimensional space, and uses the least squares Multiplication estimates and separates the error components of the satellite to obtain the ephemeris error and the satellite clock error, which can be regarded as the inverse positioning of GPS. However, in the satellite navigation satellite-based augmentation system, it is very difficult to keep the time of each differential station fully synchronized. Currently, the satellite ...

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Problems solved by technology

However, in the satellite navigation satellite-based augmentation system, it is very difficult to keep the time of each differential station completely synchronized. Currently, the satellite two-way time transfer technology is used, and there will be a time synchronization error of 0.3-1 ns between the stations. If this error is adopted in an ideal situation The calculation of the vector difference principle, the station clock time synchronization error will be absorbed into the ephemeris error, affected by the error amplification of the inverse positioning DOP, the calculation accuracy of the ephemeris correction number is also greatly affected, resulting in low positioning accuracy

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