FFT tracking based high dynamic GPS/INS scalar deeply integrated navigation algorithm

Traditional GPS receiver uses the digital Costas loop for carrier tracking, which will breakdown under low SNR environment. High-sensitivity receiver is designed using FFT based tracking loop, this method could track GPS signal as weak as -163dBm, but it fails rapidly in high dynamic scene. Aided by Inertial Navigation System (INS) solutions, dynamics of the GPS receiver is estimated and removed, then effectiveness of long time FFT is guaranteed for weak signal tracking in high dynamic circumstance. A 20 ms long FFT based tracking loop is proposed in this paper with INS-aiding. Simulation results show that this preliminary algorithm can track GPS signal as weak as -148dBm in 6m/s² dynamic scene, under which the traditional FLL loose lock on the incoming signal.