Time measuring method based on double-clock system

Abstract

The invention provides a time measuring method based on a double-clock system. The method includes the steps: (1) building a system time scale, (2) calculating an actual cycle of a local clock by means of the system time scale and a second pulse clock, and (3) measuring absolute time of a pulse to be measured according to the actual cycle of the local clock. The time measuring method solves the inaccuracy problem of time in a unit smaller than second caused by non-synchronization and errors of the clock. The clock is corrected through the method that the local clock and the second pulse clock are used together to correct time, and by means of calculation of relation between the second pulse clock and the local clock, the relation between the pulse to be measured and the two clock systems is further calibrated in detail. Intrinsic time of the local clock is used for marking the absolute time of an event, relative errors between several kinds of time are eliminated, and the marking precision is extremely high.

Description

technical field [0001] The invention belongs to the technical field of high-precision time measurement, and in particular relates to a time measurement method based on a dual clock system. Background technique [0002] During the development of X-ray detectors, it is necessary to accurately measure the arrival time of each photon event. The measurement accuracy of the timing measurement system is less than 1ns. Therefore, high requirements are placed on the accuracy of each link. The arrival time of photons is passed Several times such as bus UTC time, second pulse, and local clock are jointly expressed and calculated. [0003] The result measured by the system is the absolute time of signal arrival. This absolute time is jointly determined by the second pulse signal and UTC time. But this time is only marked to the second, and the second pulse is not synchronized with the local clock, so: the signal arrival time seconds and the time above the second (minutes / hours) are ac...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the problem that the time below the second is inaccurate due to asynchrony and the error of the clock itself, the present invention provides a time measurement method based on a dual clock system, which uses the local clock and the second pulse clock to jointly correct the time To calibrate, by calculating the relationship between the second pulse clock and the local clock, and then calibrate the relationship between the measured pulse and the two clock systems in detail, cooperate with the local clock intrinsic time, mark the absolute time of the event, and eliminate the gap between several times The relative error of the mark is extremely high

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