INS-aided tracking with FFT frequency discriminator for weak GPS signal under dynamic environments

We present an approach using INS-aided GPS tracking loop with FFT frequency discriminator for tracking of dynamic weak GPS signals. In this approach, the FFT carrier frequency discriminator is used to deal with the attenuated GPS signal, and the INS is used to handle the platform dynamics. With a tactical level INS aiding, when the CN0 of the GPS signal is as low as 19 dB-Hz and the platform dynamic is as high as 100 g, the tracking results indicate that the Doppler tracking error is <4 Hz, and the code loop bandwidth can be decreased to 0.05 Hz. The positioning results show that the positioning error is <5 m and the velocity error is <0.5 m/s.