Normalized orbit parameter-based steady-state gain correction GNSS autonomous navigation system

The invention relates to a steady-state gain correction GNSS autonomous navigation system based on normalized orbit parameters. The steady-state gain correction GNSS autonomous navigation system comprises a GNSS information conversion module, an orbit extrapolation updating module, a steady-state gain Kalman filtering correction module and a steady-state gain offline calculation module. According to the method, a normalized orbit semi-major axis, an orbit inclination angle, an ascending node right ascension, an eccentricity rate vector and a flat latitude argument are adopted as state variables of navigation filtering estimation, a Cowell method is adopted to carry out one-step estimation on orbit element information, and the position under a WGS84 system output by a GNSS receiver is combined with speed information of the one-step estimation to be converted into the orbit element information. And finishing filtering correction of the orbit element information by adopting a steady-state gain Kalman filtering a