Abstract:

According to the special requirements of the acquisition time and carrier frequency for strapdown inertial navigation system (SINS)/BeiDou tightly integrated navigation system under high dynamic environment, an algorithm based on zoom-fast Fourier transformation (Zoom-FFT) that receiver captures BeiDou B1 signal with SINS is put forward in this paper. The algorithm optimizes the traditional algorithm, the parallel code phase acquisition method based on fast Fourier transformation(FFT). Then, it designs a high dynamic source for simulation and verifies the algorithm. The simulation results show that this method reduces 50% cold start-time than that without aid, the warm start-time is only about 2%, and the sensitivity of the system is improved. At the same time, the estimated carrier frequency resolution increases by more than 50 times, and the error is less than 10Hz.The optimized algorithm can meet the requirements of tracking loop in the deeply integrated navigation system under high-dynamic environment, and improve the system acquisition performance.

Key words: Strapdown inertial navigation system aided, High dynamic, BeiDou B1 signal acquisition, Zoom fast Fourier transformation