Research on Relative Navigation for Formation Flying Spacecrafts Based on Differential GNSS

【摘要】：In order to improve the precision of relative navigation for formation flying spacecrafts,a relative navigation scheme based on differential GNSS was proposed , the method of differential-pseudo-range smoothed by double-differential carrier phase was applied for the distance measurement. The measurement vector included the relative distance , azimuth and elevation between spacecrafts. The extended Kalman filter was adopted to estimate the relative position and velocity. Taking the relative dynamic formula based on non-singularity orbit elements as the state equation instead of the traditional C-W formula,the restriction of eccentricity could be ignored,the transform formula between relative non-singularity orbit elements and relative position(velocity) between spacecrafts was derived, by which the singular point in the Kepler's elements was avoided. Corresponding numerical simulation and experimental demonstration was provided to verify the precision of relative navigation,the scheme proposed by the paper was proved to be available.