The Exploration And Research On The Precision Of Measuring Time Interval Based On TDC

In recent years,with the progress of science and technology,the maturity of semiconductor,high-precision time interval measurement technology has become a major research focus,and has formed a professional discipline crossing multi-technology fields including physical,mathematical,circuits,signals and so on,which attracting a large number of researchers to join it.The application of high-precision time interval measurement technique is very widely.In many fields such as aerospace,military and national defence,deep-sea exploration,geological mapping,emission and monitoring of satellites,aircraft docking,laser ranging and scientific experiments it has important applications,and plays a significant role.There are many methods to measure the time interval with high-precision,and the precision is higher and higher.In this thesis,research and development will be carried out on the TDC-GP22 developed by time-digital converter method.Control program of TDC-GP22 is developed with the help of STM32,and Experiment is set up by TDC-GP22 to measure the length of the fiber.Control program of TDC-GP22 is designed and implemented.The control program is divided into SPI communication module,serial communication module,interrupt module,TDC module,key module and LED module.According to the characteristics and features of TDC chip,the function of each module is achieved.Finally complete the measurement for the input signal in the main function.All program development work is finished that makes TDC-GP22 can complete the measurement work.Using TDC-GP22 as a measurement system,set up an experiment to measure the length of 5km fiber.TDC-GP22 and 53230A both measure in the experiment.The 53230A is used as calibration system to calibrate the TDC-GP22.Due to the fiber is affected by mechanical vibration and temperature,delay jitter of 53230A measurement results in 400ps.Tdc-gp22 delay jitter is within 500ps,both in the acceptable range.Relative to the calibration system of 53230A,there is a deviation of 31.858m in the measurement result of TDC-GP22.After the calibration TDC-GP22 can be very good to complete the measurement work.