基于GPS的新型二级频标锁定系统

A GPS Based New Second-Class Frequency Standard Locked System

提出了一种基于GPS的新型二级频标锁定系统的设计方案。利用信号的时延稳定性和群相位差变化的规律性,产生一种基于长度游标的高精度时间间隔测量方法。将该方法应用于二级频标锁定系统中,通过对被测时间间隔进行多尺度卡尔曼滤波,在MCU控制下算出GPS与二级频标分频信号之间的相对频差;根据二级频标的频-压控制特性得到补偿电压,将该电压进行D/A转换后送到二级频标的压控端,调整输出频率,形成二级频标锁定系统。实验结果表明其锁定精度可达10-12/s量级,与传统频标锁定系统相比具有电路简单,成本低廉,附加噪声小,锁定精度高等特点。

A GPS based new design scheme for second-class frequency standard locked system is proposed in this paper.Using the delay stability of signal and the regular changes of group phase difference,a high-accuracy time interval measurement method is generated based on length vernier.If the method is used in the second-class frequency standard locked system,and the relative frequency difference between GPS and divided frequency signal of second-class frequency standard can be calculated by using multi-scale Kalman filter of measured time interval under the control of MCU.According to frequency-voltage control characteristics of second-class frequency standard,a compensation voltage can be obtained.After the compensation voltage is converted by D /A,it is sent to voltage control end.Then the output frequency of the second-class frequency standard can be adjusted.Thus the second-class frequency standard locked system is formed.Experimental results show that the system＇s locked accuracy is as high as 10-12 /s in time domain.Compared to traditional frequency standard locked system,the system has the advantages of simple structure,low cost,small additional noise and high locked accuracy.