PERFORMANCE ANALYSIS OF GNSS VECTOR TRACKING LOOP BASED GNSS/CSAC INTEGRATED NAVIGATION SYSTEM

Changhui Jiang ； Shuai Chen ； Yuwei Chen ； Yuming Bo ； Chaochen Wang ； Wei Tao

《Journal of Aeronautics, Astronautics and Aviation》 49卷4期 Vol.49 No.4 (2017/12) Pp. 289-297

https://doi.org/10.6125/17-0413-935

摘要

In the GNSS receiver, the position and velocity values are determined by the pseudo-range and pseudo-range rates respectively. For the vector tracking loop, the navigation filter estimates the navigation solutions using the measurements from the frequency discriminators and the code phase discriminators. The estimation of clock bias and clock drift are the key elements which make great impact on the performance of the vector tracking loops including the tracking and the navigation solutions. With the development of the micro-electromechanical system (MEMS) technology, the chip scale atomic clock (CSAC) is gradually cheap, small and its performance constantly improved. It becomes possible for the employment of CSAC in the receiver. In this paper, the performance of the CSAC based vector tracking is analyzed and evaluated. In the semi-physical simulation system, the CSAC is employed as the time reference as the immediate frequency data collecting equipment. An experiment was conducted and the results were presented by the comparison of the values of the dilution of position (DOP) and the accuracy of the navigation solutions. The results show the mean value of the PDOPs decease by 24.6%, 27.8%, 12.1% and 21.4% respectively (PDOP, HDOP, VDOP and TDOP) compared with the cheap oscillator based vector tracking loop.

關鍵字

GNSS ； vector tracking loop ； clock bias ； clock drift ； MEMS ； DOP