摘要
GPS信号校准晶振信号频率源系统可输出高准确度时频信号,但GPS信号在传输和接收过程中会产生随机抖动或野值,给系统频率校准带来误差。为减小GPS信号随机抖动和野值所带来的影响,根据GPS信号与晶振信号准确度互补的特点,建立GPS信号校准晶振信号频差模型,利用强跟踪滤波算法对频差信号误差进行修正。针对GPS信号中存在的野值问题,对强跟踪滤波算法进行改进,根据残差变化率的大小判别野值,利用替代法对野值加以修正,提高滤波准确度。将该方法应用于某GPS信号校准晶振信号频率源系统,可使系统输出频率准确度达到10-11量级。
GPS-signal calibrating crystal oscillator frequency source can output high-precision frequency signal. However, errors appear in the system because of the influence of random jitter and outliers effecting to GSP-signals in the transmitting and receiving process. To decrease the effect of random jitter and outliers, according to the complementarities between GPS-signal and crystal oscillator, a frequency difference model for GPS-signal calibrating crystal oscillator is proposed, applying strong tracking filter algorithm to correct errors of frequency difference signal. In order to solve the outliers problem, improving the strong tracking filter and according to the variety of residual difference, outliers can be corrected with substitution method, which can improve the precision of strong tracking filter algorithm. Applying the proposed method to a GPS-signal calibrating crystal oscillator frequency source, the result shows that the system can output a high-precision frequency of 10-11 through the improved strong tracking filter algorithm.
出处
《中国测试》
CAS
北大核心
2016年第8期13-16,63,共5页
China Measurement & Test
基金
国家杰出青年基金项目(61025014)
国家自然科学基金项目(61573365)
关键词
GPS校频
晶振
强跟踪滤波
野值
GPS calibrating frequency
crystal oscillator
strong tracking filter
outliers
