Methods Of Frequency Stability Measurement And Realization Of System

Test rang track and measure the flighting missle, acquisite the data to process and analysis.To measure the data accurately,there are lots of measurement control facilities in launch site and the navigation area,and most of monitoring stations and tested instruments are placed on hills and seaside highland where the vision is broad. In range environment, there are various instruments and equipments,at the same time, there are also lots of interference and noise. It is an important work to measure the frequency's stability of these measurement devices to ensure the reliability of the tested equipments. For the special requirements of outdoor rang environment to mobility, rapidity and automation of the frequency measurement, this paper study the realization of the stability measurement of frequency with frequency difference multiplication method which is continuous sampling, an integrated and automatic measurement system is designed which has the advantages of anti-interference and low noise and improve the stability of frequency measurement in complex environment.This paper discusses the principles and feasibility of the realization of stability measurement of frequency with frequency difference multiplocation method which is continous sampling,analyse and discusses the theory of measurement data procssing,process and analysis the continuously sampled data,and a whole system is designed.The hardware system includes mixer, continuous sampling module,data communication interfaces.The mixer is double balanced, making use of filter to remove clutter in the generated frequency component signal and the method of quadratic amplification shaping to overcome the counting error. In the continuous sampling module,the dual-channel counting method is applied,the standard frequency is used to mix,the output signal of frequency division is used to design sample circuit,so not only the circuit design is reduced,and the time base accuracy of standard frequency is made full use,the purpose of reducing noise is achieved, the most important is the continuous sampling is realized,so that the frequency stability parameter can be evaluated correctly and the system uncertainty can be analysed according to the theory of data processing.Data communication interfaces ensure the accurate communication between devices, computers and the measurement system.Basing on Visual Basic and LABVIEW, the system software is designed to realize the automatic measurement, data processing and results analysis.The Value transfer of the frequency measurement instruments specify that the certification and analysis of various system parameters and indexs can only be traced to parent unit.In Beijing Institute of Radio Metrology and Measurement the system is tested,the comparison uncertainty of 10s stability is 8×10-14, the comparison uncertainty of 10s accuracy is 5×10-13.The integral system design can be applied in complex field range environment, avoiding the interference of multi-level connections to system measurement, and the various parameters reflecting the frequency stability can be measured individually in accordance with the procedures set. Interactive and automation is achieved in the process of measurement.