A useful Doppler radar outlier elimination algorithm based on orthogonality of innovation

In order to solve the problem that the precision and stability of Doppler radar/Fiber Optical Gyroscope Strapdown Inertial Naivgation System (FOG-SINS)/Barometer Integrated Navigation System (DFBINS) for helicopters will be highly affected if there are outliers in doppler radar, especially consecutive outliers appear, a useful method to eliminate these outliers based on orthogonality of innovation is proposed in this paper. Outliers in Doppler radar can be detected by judging whether the orthogonality of innovation in Kalman filter is lost or not, and an activation function as the weight factor to each element of observation is assigned, so it can keep innovation sequence of kalman filter orthogonal and outliers can be detected and corrected. The excellent results of digital simulation for a long distance straight line flying test show that the modified method is effectively resistant to the adverse effects on accuracy and stability of DFBINS caused by outliers in Doppler radar, the proposed algorithm is of high value in practice.