Error analysis and optimal bandwidth design for SINS-aided GPS tracking loop

Design of the strapdown inertial navigation system (SINS) aided global positioning system (GPS) tracking loop is the primary process in the realization of the SINS/GPS ultra-tight integration system, and the loop bandwidth selection is the key to balance the performance of tracking loop under different error sources. Firstly, the error sources affecting the tracking performance of the phase lock loop (PLL) were modeled and analyzed. Then, on the principle of minimizing the tracking error of the SINS-aided PLL, an optimal adjustment method of the loop bandwidth according to the carrier-to-noise ratio detected by GPS receiver was proposed to keep PLL in optimal tracking state. Analysis results show that this method can effectively improve the anti-jamming performance as well as the tracking accuracy of the SINS-aided PLL.