Abstract: To solve the problem of bad GPS tracking performance under high dynamic condition, a new tracking method integrated with frequencylocked loop (FLL) and phase-locked loop (PLL) was proposed. A judge factor is employed to define the current tracking state. In order to regulate the relative contribution of FLL and PLL to the tracking process, the FLL and PLL outputs are given with different weights based on the judge factor. This weight adjustment can perform a better integration of FLL and PLL in the tracking process. The simulation results prove that the method can be used to track the GPS signal of 150 g acceleration with small noise bandwidth.

Key words: global positioning system (GPS), high dynamic condition tracking, integration of frequency lock loop(FLL) and phase lock loop(PLL), weight adjustment