A method for measuring the resolution of a picosecond interval measuring instrument

Abstract

The application relates to the technical field of time interval measurement, and discloses a method for measuring the resolution of a picosecond-level time interval measuring instrument, which first determines a method for measuring and testing the resolution by using a programmable delay line device, solves the problem that the resolution cannot be tested in the past and can only be given by visual observation, and avoids the problems of false high technical indexes given by some manufacturers, influence on use experience and the like.

Description

Technical Field

[0001] This invention relates to the field of time interval measurement technology, and more specifically, to a method for measuring the resolution of a picosecond-level time interval measuring instrument. Background Technology

[0002] High-precision time interval measurement technology plays a vital role not only in fundamental research fields such as atomic physics and geodynamics, but also in various sectors of the national economy and defense, including computer networks, mobile communications, power, finance, transportation, and heavy industry. It even has a significant impact on defense and military applications such as laser ranging, satellite navigation, and aerospace telemetry. Its applications have permeated almost every aspect of people's lives. In recent years, the development of national science and technology and the implementation of major projects such as manned spaceflight, BeiDou navigation, and lunar exploration have presented new challenges to time interval measurement technology. These challenges are manifested not only in the increased precision requirements of measuring instruments, but also in the increased demand for the number of instrument channels.

[0003] An independent and self-reliant time and frequency system is crucial to national security and core interests. Major developed countries worldwide attach great importance to the construction of their time and frequency systems; both the US and Russia have established independent and complete national time and frequency systems. Currently, my country is constructing and improving its national time and frequency system, primarily based on satellite navigation system timing, supplemented by wireless and network-based timing methods. The construction of this system encompasses timekeeping, timing synchronization, time usage, metrology calibration, and monitoring. This creates enormous demand for core time and frequency components, as well as time synchronization boards, modules, equipment, and systems, which will drive the rapid development of the entire time and frequency industry.

[0004] Time interval measurement technology plays an extremely important role in time and frequency applications and supporting fields. Scientific research, metrology and engineering applications all require time interval measurement equipment. Therefore, the development of high-precision multi-channel time interval counters will be a hot topic in the field of time and frequency.

[0005] Time interval measurement resolution is a technical indicator that users are very concerned about. The National Metrological Verification Regulation JJG238-2018 "Time Interval Measuring Instrument" gives the definition of the effective resolution of the time interval measuring instrument and directly cites the value of the effective resolution in the metrological characteristics of the maximum permissible error of time interval measurement. However, it does not give the measurement method of the effective resolution. From the terminology definition, the effective resolution is still the concept of display resolution and cannot be regarded as the actual measurement resolution of the time interval.

[0006] In response to the current situation where users of high-precision time interval measuring instruments have high requirements for the instrument's actual measurement resolution and lack relevant measurement standards, this invention proposes a method for measuring the resolution of picosecond-level time interval measuring instruments. Summary of the Invention

[0007] To overcome the aforementioned deficiencies in the existing technology, this invention provides a method for measuring the resolution of a picosecond-level time interval measuring instrument. It is the first to determine a method for measuring resolution using a programmable delay line device, which solves the problem that resolution could not be tested in the past and could only be displayed visually. This also avoids the problem of some manufacturers providing inflated technical specifications, which affects the user experience.

[0008] The above-mentioned technical objective of the present invention is achieved through the following technical solution: a method for measuring the resolution of a picosecond-level time interval measuring instrument, comprising the following steps:

[0009] S1. Turn on the time interval measuring instrument and preheat it, and confirm that the relevant signal indicator lights of the instrument are displaying normally;

[0010] S2. Set the delay of the programmable delay line device to 0;

[0011] S3. Connect the 1PPS output from the standard time frequency source and the 1PPS output from the programmable delay line device to the reference channel and measurement channel of the time interval measuring instrument, respectively. Start the measurement. The measurement result is recorded once per second by default. After continuous measurement for 100 seconds, take the average value as the initial value of the time interval measurement, and record it as t0.

[0012] S4. Based on the measurement resolution index declared by the time interval measuring instrument, set the delay amount of the programmable delay line device to be the same as the measurement resolution declared by the time interval measuring instrument, and denot it as p0.

[0013] S5. Measure the time interval between each channel and the reference channel. The measurement results are recorded at 1 time per second by default. After 100 seconds of continuous measurement, calculate the average value, denoted as t1, and obtain the following formula:

[0014] t1-t0=p0 (1)

[0015] Based on the above formula (1), the following two situations are identified:

[0016] a. If equation (1) holds, then the measurement resolution of the measuring time interval measuring instrument can be determined to be p0.

[0017] b. If equation (1) is not valid, then the delay of the programmable delay line device is gradually increased by stepping 1 / 10 of the resolution of the multi-channel time interval counter under test (if this value is less than the minimum adjustable step of the programmable delay line device, then the minimum adjustable step of the programmable delay line device is used). Each time the delay is changed, it is recorded as P0+ΔP. The time interval between each channel and the reference channel is measured. The measurement results are recorded once per second by default. After continuous measurement for 100 seconds, the average value is calculated and recorded as t'1. The following formula is obtained:

[0018] t′1-t0=P0+ΔP (2)

[0019] Based on the above formula (2), the following two situations are identified:

[0020] ① If equation (2) holds true, then the measurement resolution of the measuring time interval measuring instrument can be determined to be P0+ΔP;

[0021] ② If equation (2) still does not hold, continue to increase the delay of the programmable delay line device by the above step amount, and repeatedly measure the time interval between each channel and the reference channel until equation (2) holds. Stop the measurement. The delay adjustment amount at this time is the measurement resolution of the time interval measuring instrument.

[0022] Furthermore, the time interval measuring instrument adopts a dual-channel time interval measuring instrument or a multi-channel time interval measuring instrument.

[0023] Furthermore, the adjustable minimum step size of the programmable delay line device is less than or equal to the measurement resolution of the measuring instrument for the measured time interval.

[0024] In summary, the present invention has the following beneficial effects: The present invention is the first to determine a method for measuring resolution using a programmable delay line device, which solves the problem that resolution could not be measured in the past and could only be displayed by visual inspection; it also avoids the problem that some manufacturers give inflated technical specifications, which affects the user experience. Attached Figure Description

[0025] Figure 1 This is a connection block diagram of the time interval measurement resolution instrument in Embodiment 2 of the present invention;

[0026] Figure 2 This is a graph of the original data from the resolution test measured by the time interval measuring instrument in Embodiment 2 of the present invention. Detailed Implementation

[0027] The following is in conjunction with the appendix Figure 1-2 The present invention will be described in further detail below.

[0028] Example 1: A method for measuring the resolution of a picosecond-level time interval measuring instrument, such as... Figure 1 , Figure 2 As shown, it includes the following steps:

[0029] S1. Turn on the time interval measuring instrument and preheat it according to the instructions, and confirm that the relevant signal indicator lights of the instrument are displaying normally;

[0030] S2. Set the delay of the programmable delay line device to 0;

[0031] S3. Connect the 1PPS output from the standard time frequency source and the 1PPS output from the programmable delay line device to the reference channel and measurement channel of the time interval measuring instrument, respectively. Start the measurement. The measurement result is recorded once per second by default. After continuous measurement for 100 seconds, take the average value as the initial value of the time interval measurement, and record it as t0.

[0032] S4. Based on the measurement resolution index declared by the time interval measuring instrument, set the delay amount of the programmable delay line device to be the same as the measurement resolution declared by the time interval measuring instrument, and denot it as p0.

[0033] S5. Measure the time interval between each channel and the reference channel. The measurement results are recorded at 1 time per second by default. After 100 seconds of continuous measurement, calculate the average value, denoted as t1, and obtain the following formula:

[0034] t1-t0=p0 (1)

[0035] Based on the above formula (1), the following two situations are identified:

[0036] a. If equation (1) holds, then the measurement resolution of the measuring time interval measuring instrument can be determined to be p0.

[0037] b. If equation (1) is not valid, then the delay of the programmable delay line device is gradually increased by stepping 1 / 10 of the resolution of the multi-channel time interval counter under test (if this value is less than the minimum adjustable step of the programmable delay line device, then the minimum adjustable step of the programmable delay line device is used). Each time the delay is changed, it is recorded as P0+ΔP. The time interval between each channel and the reference channel is measured. The measurement results are recorded once per second by default. After continuous measurement for 100 seconds, the average value is calculated and recorded as t'1. The following formula is obtained:

[0038] t'1-t0=P0+ΔP (2)

[0039] Based on the above formula (2), the following two situations are identified:

[0040] ① If equation (2) holds true, then the measurement resolution of the measuring time interval measuring instrument can be determined to be P0+ΔP;

[0041] ② If equation (2) still does not hold, continue to increase the delay of the programmable delay line device by the above step amount, and repeatedly measure the time interval between each channel and the reference channel until equation (2) holds. Stop the measurement. The delay adjustment amount at this time is the measurement resolution of the time interval measuring instrument.

[0042] The time interval measuring instrument can be a dual-channel time interval measuring instrument or a multi-channel time interval measuring instrument, with one channel set as the reference channel and the remaining channels as measurement channels; the adjustable minimum step of the programmable delay line device is less than or equal to the measurement resolution of the time interval measuring instrument under test.

[0043] Example 2: Experimental Verification:

[0044] This embodiment uses a time interval measuring instrument with a resolution of 10 ps as an example for testing and verification. Connecting the instruments and equipment is as follows: Figure 1 As shown, the 1PPS power output from the standard time and frequency source is divided into two paths. One path is input to the reference channel of the time interval measuring instrument, and the other path is input to the programmable delay line device. The 1PPS signal output from the programmable delay line device is input to the measurement channel of the time interval measuring instrument. After warming up according to the time specified in the instrument manual, the measurement is performed. The delay of the programmable delay line device is adjusted by 10ps each time, and the continuous measurement is performed for 200s after each adjustment. A total of 5 adjustments are made. The raw data obtained are shown below. Figure 2 As shown in Table 1 below, the average values ​​for each measurement are:

[0045] Table 1. Time interval measurement data and calculated average values.

[0046]

[0047] Combination Figure 2 Based on the data in Table 1, it can be concluded that the actual measurement resolution of the time interval measuring instrument is 10 ps.

[0048] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A method for measuring the resolution of a picosecond-level time interval measuring instrument, characterized in that, Includes the following steps: S1. Turn on the time interval measuring instrument and preheat it, and confirm that the relevant signal indicator lights of the instrument are displaying normally; S2. Set the delay of the programmable delay line device to 0; S3. Connect the 1PPS output from the standard time and frequency source and the 1PPS output from the programmable delay line device to the reference channel and measurement channel of the time interval measuring instrument, respectively. Start the measurement. The measurement result is recorded at 1 time per second by default. After 100 seconds of continuous measurement, take the average value as the initial value of the time interval measurement, denoted as . ; S4. Based on the measurement resolution specification declared by the time interval measuring instrument, set the delay of the programmable delay line device to be the same as the measurement resolution declared by the time interval measuring instrument, denoted as... ; S5. Measure the time interval between each channel and the reference channel. The measurement results are recorded at 1 time per second by default. After 100 seconds of continuous measurement, calculate the average value and record it as follows. The following formula is derived: - = （1） Based on the above formula (1), the following two situations are identified: a. If equation (1) holds, then the measurement resolution of the time interval measuring instrument can be determined to be: ; b. If equation (1) is not valid, then measure 1 / 10 of the resolution using the multi-channel time interval measuring instrument under test; if this value is less than the minimum adjustable step of the programmable delay line device, then gradually increase the delay amount of the programmable delay line device using the minimum adjustable step of the programmable delay line device as the step amount; each change in delay amount is recorded as... The time interval between each channel and the reference channel is measured. The measurement results are recorded at 1 time per second by default. After 100 seconds of continuous measurement, the average value is calculated and recorded as follows. The following formula is derived: （2） Based on the above formula (2), the following two situations are identified: ① If equation (2) holds, then the measurement resolution of the measuring instrument for the measured time interval can be determined to be . ; ② If equation (2) still does not hold, continue to increase the delay of the programmable delay line device by the above step amount, and repeatedly measure the time interval between each channel and the reference channel until equation (2) holds; stop the measurement, and the delay adjustment amount at this time is the measurement resolution of the time interval measuring instrument.

2. The method for measuring the resolution of a picosecond-level time interval measuring instrument according to claim 1, characterized in that, The time interval measuring instrument is either a dual-channel time interval measuring instrument or a multi-channel time interval measuring instrument.

3. The method for measuring the resolution of a picosecond-level time interval measuring instrument according to claim 1, characterized in that, The adjustable minimum step of the programmable delay line device is less than or equal to the measurement resolution of the measuring instrument for the measured time interval.

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