Mean orbit element-based relative navigation robust filtering method

Abstract

The invention discloses a mean orbit element-based relative navigation robust filtering method. The method comprises the following steps: 1, deriving a relative navigation state equation according to relative kinematics of formation flying satellites, measuring the intersatellite real-time relative positions and speeds through using CDGPS, and filtering measured data through an EKF algorithm to obtain a relative mean orbit element; 2, outputting formation configuration parameters after filtering is stable; and 3, carrying out prediction and recursion according to a relationship among the relative positions, the relative speeds and the configuration parameters in order to obtain intersatellite relative positions.

Description

technical field [0001] The invention relates to a relative navigation robust filtering technology based on orbit flat root number. Background technique [0002] The key to satellite formation flight to achieve ground interferometry is to maintain the required space formation configuration during formation flight, and the formation maintenance control depends on the navigation, guidance and control (Navigation, Guidance and Control, referred to as: GNC) system. The determined formation configuration parameters are to achieve high-precision real-time relative navigation between satellites. At present, the relative position and velocity measurement between satellites is generally realized by GPS carrier phase difference (GPS carrier phase difference, referred to as: CDGPS) method, but the information obtained by this method is an independent position point, not a formation structure. shape parameters, so high-precision, high-robust relative navigation filtering technolog...

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Problems solved by technology

[0017] Since the C-W equation gives the relationship between relative motion and instantaneous orbital elements, this description based on instantaneous elements is very sensitive to the initial parameters. When the initial parameters deviate slightly, the actual relative motion will be different from the real value. The deviation is very large, and the instantaneous root number has the characteristics of obvious error accumulation over time, so it is not conducive to the relative navigation of formation satellites

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