Research And Design Of High Precision Event Timer

Event timing technology has very important applications in the fields of star-toground,high-frequency laser ranging,atomic physics and so on,including multidisciplinary knowledge such as analog circuit,instrument science,digital circuit and signal processing.The event timer is introduced into the modern satellite laser ranging system,which greatly improves the working frequency and significantly improves the ranging accuracy.At present,the research on event timing technology in foreign countries is relatively mature,and the research on this technology in China started late with few achievements.The use of instruments are basically dependent on imports.This topic is put forward in this context.The most important feature of event timer is that it can record the real time when the event occurs,and high speed and precision are its core competitiveness.In this paper,the principle of event timer is studied and a high precision event timer is implemented.Combined with the subject index,this paper focuses on the following aspects of research work:1.Combined with the principle and actual needs of event timer,a coarse measuring module with resolution of 5 nanoseconds is designed,and the timing range is up to 43 seconds.2.Several commonly used time interval measurement schemes is deeply studied,and finally TDC method based on delay line interpolation is selected.The resolution of event timer fine time interval module reaches 13 ps.3.According to the requirements of timing and repetition frequency in the subject,an appropriate data transmission strategy is designed to realize the data interaction between the event timer and the computer.It mainly includes hardware design,protocol design and the programming of software upper computer.4.The temperature and voltage monitoring module are designed and implemented,which can monitor the working state of the event timer in real time,provide a reasonable basis for external safeguard measures,and further improve the accuracy index of the event timer.5.The time drift caused by the long-term operation of the event timer will greatly affect the time stability,so a self-correction algorithm is studied to correct the drift and improve the time stability.At the same time,the method of evaluating the moment stability is studied,and the test data is analyzed and verified by this method.The final test results showed that the event timer achieved has a high accuracy: the timing repetition frequency reaches 10 kHz,the temperature drift rate is 0.194ps/K,the short-term stability is 0.01787ps@300s,the long-term stability is 0.0605ps@1day,and all the indicators meet the actual requirements.