Doppler-aided positioning based on Kalman filtering method for fused LEO navigation systems

LEO navigation systems have the potential to supplement and back up GNSS services, and Doppler-aided positioning has been proposed to address insufficient pseudorange measures due to a lack of navigational resources or the early phases of system development. To improve Doppler-aided positioning precision, we introduce the Kalman filtering method to Doppler-aided positioning for fused LEO navigation systems. Simulation results indicate that this method and pseudorange positioning achieve comparable accuracy when more than four pseudorange measurements are available. However, when fewer than four pseudorange measurements are available, Doppleraided positioning based on Kalman filtering can maintain 95% of the three-dimensional errors within 0.5 meters. The above results mean that Doppler-aided positioning based on Kalman filtering can simultaneously maintain service availability and improve positioning precision.