Method and device for measuring gravitational potential difference by GNSS carrier phase single clock

Abstract

The invention relates to the technical field of geodetics and geophysics, in particular to a method and device for measuring gravitational potential difference through a GNSS carrier phase single clock, and the method comprises the steps: determining a first relative frequency difference according to a first receiver clock difference sequence of a target atomic clock of a first observation station relative to a reference clock in a target observation time period; determining a second relative frequency difference according to a second receiver clock difference sequence of a target atomic clock of a second observation station relative to the reference clock in the target observation time period; and determining a gravity frequency shift of the target atomic clock between the first observation station and the second observation station by using a difference value between the first relative frequency difference and the second relative frequency difference, so as to determine a gravity potential difference measured based on the GNSS carrier phase single clock between the first observation station and the second observation station according to the gravity frequency shift. Therefore, the problems that in the prior art, the requirement for satellite data precision is extremely high, errors are prone to being influenced, or the number of common-view satellites is relied on, long-distance application is limited, and the accuracy and flexibility of gravitational potential difference measurement are reduced are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of geodesy and geophysics, and in particular to a method and device for measuring gravity potential difference using a GNSS carrier phase single clock. Background Art

[0002] Gravity potential is a fundamental element of the Earth's gravitational field. As one of the key physical fields supporting seismology, geodynamics, aerospace, meteorology, oceanography, natural disaster research, national defense, and economic development, its accurate and reliable measurement is a core task of geodesy. Traditional methods for measuring gravity potential differences rely on a combination of leveling and gravity measurements. However, these methods suffer from limitations such as error accumulation, difficulty in cross-ocean transmission, and time and labor costs, posing significant challenges in cross-island measurements and global elevation datum unification. A new method for measuring gravity potential differences, known as "clock positioning," has emerged, based on the gravity frequency shift equation and using high-performance atomic clocks combined with frequency transfer technology for clock-to-clock comparisons. This innovative method can be used not only to determine gravity potential differences and orthometric height differences, but also for unifying elevation datums, monitoring vertical surface motion caused by volcanic eruptions, tides, earthquakes, and other activities, and eliminating gravitational redshift errors in optical clock comparisons.

[0003] Current experiments using clock positioning to measure gravitational potential differences between two locations can be roughly divided into two categories: the first employs fiber-optic frequency transfer, and the second relies on time-frequency transmission links established via microwave or laser signals from satellites or space stations. Each method has its own advantages and limitations. Fiber-optic frequency transmission, leveraging the exceptional stability and low uncertainty of optical clocks, can achieve accuracies on the order of 10⁻¹⁸ or better. Furthermore, the errors introduced by fiber-optic signal transmission are extremely low, resulting in comparable or even superior results to traditional leveling combined with gravity measurements. However, this method requires establishing fiber-optic links between sites, which is costly and inflexible. While suitable for backbone control network construction, it is difficult to scale up. In contrast, satellite-based time-frequency transmission methods require addressing the core challenge of eliminating link errors. Because they rely on free-space signal transmission, various atmospheric errors can significantly reduce the stability and accuracy of the time-frequency transmission, thereby limiting overall performance. However, this method can achieve clock comparison between any two locations in the world, is not restricted by ground connections, and has abundant satellite resources available, including GNSS (Global Navigation Satellite System), communication satellites, low-orbit satellites, and space station signal relay links. These advantages provide a broad platform for future research and application of gravity potential difference measurement.

[0004] Several experiments have used GNSS satellites to transfer time and frequency to measure gravitational potential differences between remote sites. These experiments require synchronized operation of two atomic clocks to directly compare the clock errors at the two sites. Therefore, each experiment requires at least two identical sets of equipment: one set is transported to the target site, and the other serves as a reference clock to enable comparison between the local and remote clocks. The GNSS time and frequency transfer techniques used in these experiments can be divided into two categories: the first, called Precise Point Positioning Time-Frequency Transfer (PPP-TFT), calculates the clock error between the local clock and a reference time scale separately and then subtracts the two results to eliminate the reference time scale; the second, called Single-Differenced Time-Frequency Transfer (SD-TFT), directly calculates the difference between the clock errors of the two clocks and the reference time scale, eliminating the reference time scale from the observation equation. Notably, PPP-TFT supports single-point solutions, enabling time and frequency transfer over extremely long distances. This feature is particularly useful for unifying global elevation datums. The SD-TFT technology can effectively eliminate most satellite-related errors and some atmospheric errors, but its implementation requires a sufficient number of common-view satellites between the two stations.

[0005] Among related technologies, although PPP-TFT supports ultra-long-distance time and frequency transmission and is suitable for global elevation benchmark unification, it has extremely high requirements on the accuracy of external data such as satellite orbits and clock errors. Any error will directly affect the final time comparison accuracy. In addition, although SD-TFT can effectively eliminate most satellite-related errors and some atmospheric errors, this method relies on a sufficient number of common-view satellites between the two stations, which limits its application in long-distance links and may make it difficult to obtain reliable data under certain geographical conditions, reducing the accuracy and flexibility of measuring gravity potential differences, which urgently needs to be solved. Summary of the Invention

[0006] The present invention provides a method and device for measuring gravity potential difference using a single GNSS carrier phase clock, so as to solve the problems in related technologies such as extremely high requirements for satellite data accuracy, susceptibility to errors, or reliance on the number of common-view satellites, which limits long-distance applications and reduces the accuracy and flexibility of measuring gravity potential difference.

[0007] A first aspect of the present invention provides a method for measuring gravity position difference using a GNSS carrier phase single clock, comprising the following steps: obtaining a first receiver clock difference sequence of a target atomic clock at a first station relative to a reference clock within a target observation period, and determining a first relative frequency difference of the target atomic clock relative to the reference clock based on the first receiver clock difference sequence; obtaining a second receiver clock difference sequence of the target atomic clock at a second station relative to the reference clock within the target observation period, and determining a second relative frequency difference of the target atomic clock relative to the reference clock based on the second receiver clock difference sequence; determining a gravity frequency shift of the target atomic clock between the first station and the second station based on the difference between the first relative frequency difference and the second relative frequency difference, so as to determine the gravity position difference between the first station and the second station based on the measurement of the global navigation satellite system GNSS carrier phase single clock according to the gravity frequency shift.

[0008] Optionally, in one embodiment of the present invention, determining the first relative frequency difference of the target atomic clock relative to the reference clock based on the first receiver clock difference sequence includes: obtaining the initial receiver clock difference sequence of the target atomic clock of the first measuring station relative to the reference clock for each day within the target observation period; converting the initial receiver clock difference sequence into an initial relative frequency difference sequence, and performing data processing on the initial relative frequency difference sequence to obtain a processed relative frequency difference sequence; determining the initial relative frequency difference between the target atomic clock and the reference clock based on the mean of the processed relative frequency difference sequence; determining the weight of the mean of the processed relative frequency difference sequence based on the frequency stability of the initial relative frequency difference; and determining the first relative frequency difference of the target atomic clock of the first measuring station relative to the reference clock within the target observation period based on the weight of the mean of the processed relative frequency difference sequence.

[0009] Optionally, in one embodiment of the present invention, determining the first relative frequency difference of the target atomic clock at the first measuring station relative to the reference clock during the target observation period based on the weight of the mean of the processed relative frequency difference sequence includes: determining the weighted average of the daily relative frequency differences between the target atomic clock at the first measuring station and the reference clock during the target observation period based on the weight of the mean of the processed relative frequency difference sequence; and determining the first relative frequency difference of the target atomic clock at the first measuring station relative to the reference clock during the target observation period based on the weighted average of the daily relative frequency differences.

[0010] Optionally, in one embodiment of the present invention, the data processing of the initial relative frequency difference sequence to obtain a processed relative frequency difference sequence includes: preprocessing the data of the initial relative frequency difference sequence by removing outliers and target interpolation to obtain a preprocessed relative frequency difference sequence; and linearly fitting the preprocessed relative frequency difference sequence to obtain the processed relative frequency difference sequence.

[0011] Optionally, in one embodiment of the present invention, the calculation formula of the gravity frequency shift is:

[0012]

[0013] Where Δf PQ / f0 is the target gravity frequency shift, is the first relative frequency difference, is the second relative frequency difference, P is the first measuring station, and Q is the second measuring station.

[0014] Optionally, in one embodiment of the present invention, the calculation formula of the gravity potential difference is:

[0015] ΔW PQ =-c 2 Δf PQ / f0

[0016] Where ΔW PQ is the gravitational potential difference, c is the speed of light in vacuum, Δf PQ / f0 is the target gravity frequency shift.

[0017] A second aspect of the present invention provides an apparatus for measuring gravity potential difference using a GNSS carrier phase single clock, comprising: a first acquisition module for acquiring a first receiver clock difference sequence of a target atomic clock at a first station relative to a reference clock during a target observation period, and determining a first relative frequency difference of the target atomic clock relative to the reference clock based on the first receiver clock difference sequence; a second acquisition module for acquiring a second receiver clock difference sequence of the target atomic clock at a second station relative to the reference clock during the target observation period, and determining a second relative frequency difference of the target atomic clock relative to the reference clock based on the second receiver clock difference sequence; and a measurement module for determining a gravity frequency shift of the target atomic clock between the first station and the second station based on a difference between the first relative frequency difference and the second relative frequency difference, so as to determine the gravity potential difference between the first station and the second station based on the measurement of the global navigation satellite system GNSS carrier phase single clock according to the gravity frequency shift.

[0018] Optionally, in one embodiment of the present invention, the first acquisition module includes: an acquisition unit, used to obtain the daily initial receiver clock difference sequence of the target atomic clock of the first measuring station relative to the reference clock within the target observation period; a conversion unit, used to convert the initial receiver clock difference sequence into an initial relative frequency difference sequence, and perform data processing on the initial relative frequency difference sequence to obtain a processed relative frequency difference sequence; a first determination unit, used to determine the initial relative frequency difference between the target atomic clock and the reference clock based on the mean of the processed relative frequency difference sequence; a second determination unit, used to determine the weight of the mean of the processed relative frequency difference sequence based on the frequency stability of the initial relative frequency difference; and a third determination unit, used to determine the first relative frequency difference of the target atomic clock of the first measuring station relative to the reference clock within the target observation period based on the weight of the mean of the processed relative frequency difference sequence.

[0019] Optionally, in one embodiment of the present invention, the third determination unit includes: a first determination subunit, used to determine the weighted average of the daily relative frequency differences between the target atomic clock of the first measuring station and the reference clock within the target observation period based on the weight of the mean of the processed relative frequency difference sequence; and a second determination subunit, used to determine the first relative frequency difference of the target atomic clock of the first measuring station relative to the reference clock within the target observation period based on the weighted average of the daily relative frequency differences.

[0020] Optionally, in one embodiment of the present invention, the conversion unit includes: a first processing subunit, used to perform data preprocessing on the initial relative frequency difference sequence by removing outliers and target interpolation to obtain a preprocessed relative frequency difference sequence; and a second processing subunit, used to perform linear fitting on the preprocessed relative frequency difference sequence to obtain the processed relative frequency difference sequence.

[0021] Optionally, in one embodiment of the present invention, the calculation formula of the gravity frequency shift is:

[0022]

[0023] Where Δf PQ / f0 is the target gravity frequency shift, is the first relative frequency difference, is the second relative frequency difference, P is the first measuring station, and Q is the second measuring station.

[0024] Optionally, in one embodiment of the present invention, the calculation formula of the gravity potential difference is:

[0025] ΔW PQ =-c 2 ΔfPQ / f0

[0026] Where ΔW PQ is the gravitational potential difference, c is the speed of light in vacuum, Δf PQ / f0 is the target gravity frequency shift.

[0027] A third aspect of the present invention provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement a method for determining gravity potential difference using a single clock of a GNSS carrier phase as described in the above embodiment.

[0028] A fourth aspect of the present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the above method for measuring gravity potential difference using a single clock of a GNSS carrier phase.

[0029] A fifth aspect of the present invention provides a computer program product, comprising a computer program, which, when executed, is used to implement the above method for measuring gravity potential difference using a GNSS carrier phase single clock.

[0030] The embodiments of the present invention can determine a first relative frequency difference based on a first receiver clock difference sequence of a target atomic clock at a first station relative to a reference clock during a target observation period, and determine a second relative frequency difference based on a second receiver clock difference sequence of a target atomic clock at a second station relative to a reference clock during a target observation period. The difference between the first relative frequency difference and the second relative frequency difference can then be used to determine the gravity frequency shift of the target atomic clock between the first station and the second station. The gravity frequency shift can then be used to determine the gravity position difference between the first station and the second station based on the GNSS carrier phase single clock measurement, effectively improving the accuracy and flexibility of measuring gravity position difference. This solves the problems in related technologies such as extremely high satellite data accuracy requirements, susceptibility to errors, or reliance on the number of common-view satellites, which limits long-distance applications and reduces the accuracy and flexibility of measuring gravity position difference.

[0031] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0033] Figure 1 This is a flowchart of a method for measuring gravity potential difference using a single GNSS carrier phase clock according to an embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram showing the principle of measuring gravity potential difference using a single GNSS carrier phase clock according to a specific embodiment of the present invention;

[0035] Figure 3 This is a schematic diagram of a process for measuring gravity potential difference using a single GNSS carrier phase clock according to a specific embodiment of the present invention;

[0036] Figure 4 This is a schematic diagram of an experiment for measuring gravity potential difference using a single GNSS carrier phase clock according to a specific embodiment of the present invention;

[0037] Figure 5 This is a schematic diagram of the relative frequency difference results between two stations in an experiment of measuring gravity potential difference using a single GNSS carrier phase clock according to a specific embodiment of the present invention;

[0038] Figure 6 A schematic diagram of the structure of a device for measuring gravity potential difference using a single GNSS carrier phase clock according to an embodiment of the present invention;

[0039] Figure 7 A schematic structural diagram of an electronic device provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0040] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0041] The following describes a method and apparatus for measuring gravity displacement using a single GNSS carrier phase clock according to an embodiment of the present invention with reference to the accompanying drawings. To address the issues mentioned in the background art center, such as the extremely high accuracy requirements for satellite data, susceptibility to errors, or reliance on the number of satellites in common view, which limits long-distance applications and reduces the accuracy and flexibility of measuring gravity displacement, the present invention provides a method for measuring gravity displacement using a single GNSS carrier phase clock. In this method, a first relative frequency difference can be determined based on a first receiver clock difference sequence of a target atomic clock at a first station relative to a reference clock during a target observation period, and a second relative frequency difference can be determined based on a second receiver clock difference sequence of a target atomic clock at a second station relative to the reference clock during the target observation period. The difference between the first relative frequency difference and the second relative frequency difference is then used to determine the gravity frequency shift of the target atomic clock between the first station and the second station. The gravity displacement between the first station and the second station, measured using the GNSS carrier phase clock, can then be determined based on the gravity frequency shift, effectively improving the accuracy and flexibility of measuring gravity displacement. This solves the problems in related technologies such as extremely high requirements for satellite data accuracy, susceptibility to errors, or reliance on the number of common-view satellites, limiting long-distance applications, and reducing the accuracy and flexibility of measuring gravity potential differences.

[0042] Before introducing a method for measuring gravity position difference using a GNSS carrier phase single clock according to an embodiment of the present invention, a device for measuring gravity position difference using a GNSS carrier phase single clock involved in the method for measuring gravity position difference using a GNSS carrier phase single clock according to the present invention is briefly introduced.

[0043] The present invention establishes a device for measuring gravity potential difference using a single GNSS carrier phase clock. The device includes a high-performance atomic clock, a GNSS time and frequency receiver, a GNSS antenna, and related cables. The present invention can place the device at a measurement site for GNSS observation.

[0044] like Figure 1 As shown, Figure 1 A flowchart of a method for measuring gravity potential difference using a single GNSS carrier phase clock is provided in an embodiment of the present invention. The method for measuring gravity potential difference using a single GNSS carrier phase clock comprises the following steps:

[0045] In step S101, a first receiver clock difference sequence of a target atomic clock at a first measuring station relative to a reference clock in a target observation period is obtained, and a first relative frequency difference of the target atomic clock relative to the reference clock is determined based on the first receiver clock difference sequence.

[0046] In an embodiment of the present invention, the target observation period is the number of days for GNSS observations to be performed at a measurement site, which can be specifically set by relevant technical personnel; the first measurement station is the measurement station before the above-mentioned equipment for measuring gravity potential difference is transported; the target atomic clock is the high-performance atomic clock in the above-mentioned equipment; the first receiver clock difference sequence is the measurement station before transport, that is, the receiver clock difference sequence of the high-performance atomic clock of the P station relative to the IGS time reference clock; the first relative frequency difference is the relative frequency difference of the high-performance atomic clock of the P station relative to the IGS time reference clock.

[0047] It is understandable that the embodiment of the present invention can obtain a first receiver clock difference sequence of the target atomic clock of the first measuring station relative to the reference clock during the target observation period, for example, in combination with Figure 2 and Figure 3 As shown, the present invention can place the above equipment at a site for GNSS observation. The observation time can be set to 19 days. Then, the receiver clock error Δt of the first measuring station P is calculated using GNSS PPP-TFT. r , that is, high-performance atomic clock t r and the reference clock, that is, IGS time t G The time difference between G It is a very stable time scale, then the receiver clock error of station P can be expressed as:

[0048]

[0049] in, represents the time when the high-performance atomic clock is at station P, t G is the time scale, is the receiver clock error of station P.

[0050] Then, the slope of the receiver clock difference sequence at station P can be obtained by least square fitting, and this slope is approximately equal to the relative frequency difference between the high-performance atomic clock at station P and the IGS time reference clock, that is, This helps reduce the effects of hardware delays, unmodeled errors, and other noise.

[0051] It should be noted that the precision products generated by each data analysis center in the present invention are all based on stable time standards such as IGS time.

[0052] Optionally, in one embodiment of the present invention, determining a first relative frequency difference of a target atomic clock relative to a reference clock based on a first receiver clock difference sequence includes: obtaining an initial receiver clock difference sequence of the target atomic clock at the first measuring station relative to the reference clock for each day within a target observation period; converting the initial receiver clock difference sequence into an initial relative frequency difference sequence, and performing data processing on the initial relative frequency difference sequence to obtain a processed relative frequency difference sequence; determining an initial relative frequency difference between the target atomic clock and the reference clock based on a mean of the processed relative frequency difference sequence; determining a weight of a mean of the processed relative frequency difference sequence based on a frequency stability of the initial relative frequency difference; and determining the first relative frequency difference of the target atomic clock at the first measuring station relative to the reference clock within the target observation period based on the weight of the mean of the processed relative frequency difference sequence.

[0053] During actual implementation, an embodiment of the present invention can perform PPP-TFT processing on the daily GNSS observation data of the first measuring station within the observation time period, i.e., station P, to obtain the initial receiver clock difference sequence of the day, i.e., the time difference between the high-performance atomic clock of station P and the IGS time reference clock; then, the initial receiver clock difference sequence is converted into an initial relative frequency difference sequence, and the initial relative frequency difference sequence is subjected to data processing in the following steps, such as removing outliers and appropriate interpolation, to obtain a processed relative frequency difference sequence.

[0054] Secondly, the mean of the processed relative frequency difference sequence is calculated, and the mean of the processed relative frequency difference sequence is used as the initial relative frequency difference between the high-performance atomic clock of station P and the IGS time reference clock on that day. The frequency stability of the initial relative frequency difference is used as the weight of the mean of the processed relative frequency difference sequence on that day. Then, the weight of the mean of the processed relative frequency difference sequence is used to determine the relative frequency difference between the high-performance atomic clock of station P and the IGS time reference clock during the observation period, thereby improving the accuracy and reliability of the relative frequency difference estimation, which is conducive to improving the accuracy of gravity potential difference measurement.

[0055] Optionally, in one embodiment of the present invention, based on the weight of the mean of the processed relative frequency difference sequence, the first relative frequency difference of the target atomic clock of the first station relative to the reference clock in the target observation period is determined, including: based on the weight of the mean of the processed relative frequency difference sequence, determining the weighted average value of the daily relative frequency differences between the target atomic clock of the first station and the reference clock in the target observation period; and determining the first relative frequency difference of the target atomic clock of the first station relative to the reference clock in the target observation period according to the weighted average value of the daily relative frequency differences.

[0056] As a possible implementation method, an embodiment of the present invention can determine the weighted average of the daily relative frequency differences between the high-performance atomic clock of the P station and the IGS time reference clock during the observation period based on the weight of the mean of the processed relative frequency difference sequence. Then, the relative frequency difference between the high-performance atomic clock of the P station and the IGS time reference clock during the observation period is determined based on the weighted average of the daily relative frequency differences, that is, the overall relative frequency difference result of the observation period is obtained, which effectively improves the accuracy of the relative frequency difference.

[0057] Optionally, in one embodiment of the present invention, data processing is performed on the initial relative frequency difference sequence to obtain a processed relative frequency difference sequence, including: data preprocessing of the initial relative frequency difference sequence by removing outliers and target interpolation to obtain a preprocessed relative frequency difference sequence; and linear fitting of the preprocessed relative frequency difference sequence to obtain a processed relative frequency difference sequence.

[0058] In some embodiments, the embodiments of the present invention can perform data preprocessing on the initial relative frequency difference sequence by removing outliers and performing appropriate interpolation to obtain a preprocessed relative frequency difference sequence. Then, the preprocessed relative frequency difference sequence is linearly fitted, and the slope is treated as a frequency drift and removed to obtain a processed relative frequency difference sequence. In this way, the present invention can effectively suppress the influence of noise and frequency drift, improve the accuracy and stability of the relative frequency difference sequence, and provide high-quality data support for subsequent gravity potential difference measurements.

[0059] In step S102, a second receiver clock difference sequence of a target atomic clock at a second measuring station relative to a reference clock within a target observation period is obtained, and a second relative frequency difference of the target atomic clock relative to the reference clock is determined based on the second receiver clock difference sequence.

[0060] In an embodiment of the present invention, the second measuring station is the measuring station after the above-mentioned equipment for measuring the gravitational potential difference is transported; the second receiver clock difference sequence is the measuring station after the transport, that is, the receiver clock difference sequence of the high-performance atomic clock of station Q relative to the IGS time reference clock; the second relative frequency difference is the relative frequency difference of the high-performance atomic clock of station Q relative to the IGS time reference clock.

[0061] It is understandable that the embodiment of the present invention can obtain the second receiver clock difference sequence of the target atomic clock of the second measuring station relative to the reference clock during the observation period, for example, in combination with Figure 2 and Figure 3 As shown, the present invention can transport the above equipment to another site for GNSS observation. The observation time can be set to 19 days. Then, the receiver clock error Δt of the second station Q is calculated using GNSS PPP-TFT. r , that is, high-performance atomic clock t r and the reference clock, that is, IGS time t GThe time difference between the two stations is , and the receiver clock error of station Q can be expressed as:

[0062]

[0063] in, represents the time when the high-performance atomic clock is at station Q, t G is the time scale, is the receiver clock error of station Q.

[0064] Then, the slope of the receiver clock difference sequence at station Q can be obtained by least square fitting, and this slope is approximately equal to the relative frequency difference between the high-performance atomic clock at station Q and the IGS time reference clock, that is, This helps reduce the effects of hardware delays, unmodeled errors, and other noise.

[0065] It should be noted that the second receiver clock difference sequence and the second relative frequency difference of the second measuring station are determined in the same manner as those of the first measuring station, and therefore, they will not be described in detail here.

[0066] In step S103, based on the difference between the first relative frequency difference and the second relative frequency difference, the gravity frequency shift of the target atomic clock between the first station and the second station is determined, so as to determine the gravity potential difference between the first station and the second station based on the global navigation satellite system GNSS carrier phase single clock measurement according to the gravity frequency shift.

[0067] It is understandable that the embodiment of the present invention can determine the gravitational frequency shift of the target atomic clock between the first measuring station and the second measuring station according to the difference between the first relative frequency difference and the second relative frequency difference, that is, combining Figure 2 and Figure 3 As shown, the present invention can calculate the relative frequency difference between two observation periods before and after the transport of a high-performance atomic clock, thereby obtaining the gravitational frequency shift of the high-performance atomic clocks at the two stations. This can then be used to determine the gravitational potential difference between the two stations, as measured by a single clock using the Global Navigation Satellite System (GNSS) carrier phase, based on the gravitational frequency shift equation. This embodiment of the present invention can directly compare the high-performance atomic clock with IGS time, reducing processing time and conserving significant computing resources. Therefore, compared to related technologies, the single-clock method of the present invention can halve the equipment requirements. Alternatively, using two sets of equipment, it can perform parallel single-clock experiments, improving the accuracy and reliability of the results. This method is suitable for resource-constrained areas or large-scale network measurements. Furthermore, the single-clock method can reduce manpower and material resources by 50% and can be quickly deployed at temporary sites. Furthermore, the single-clock method involves only one station per observation period, providing greater flexibility and allowing for the selective discarding of problematic data segments while retaining valid observations.

[0068] The relative frequency difference between the clocks at stations P and Q before and after transport, i.e., the high-performance atomic clocks, is the gravitational frequency shift of the clocks at the two stations:

[0069]

[0070] Where Δf PQ / f0 is the target gravity frequency shift, is the first relative frequency difference, is the second relative frequency difference, P is the first measuring station, and Q is the second measuring station.

[0071] Among them, if the gravity potential of P and Q stations are W P and W Q , then the gravity potential difference between stations P and Q is:

[0072] ΔW PQ =W Q -W P

[0073] According to the gravity frequency shift formula, the gravity potential difference between stations P and Q is expressed as:

[0074] ΔW PQ =-c 2 Δf PQ / f0

[0075] Where ΔW PQ is the gravitational potential difference, c is the speed of light in vacuum, Δf PQ / f0 is the target gravity frequency shift.

[0076] Thus, the gravitational potential difference of the clock position before and after the measurement station is moved can be determined.

[0077] For example, if Figure 4 As shown, the single-clock transport experiment involved the transport of a single clock, a high-performance atomic clock, and two observation periods. First, the instrument was set up at the Luojiashan Time-Frequency Station (LTFS), establishing GNSS Station L001, for 19 days of GNSS observations. Then, the entire set of equipment was transported to the Jiugongshan Time-Frequency Station (JTFS) using a custom air-conditioned vehicle. The transport took approximately four hours, during which the clock remained powered by an uninterruptible power supply, ensuring continuous operation. GNSS observations were conducted at JTFS for 19 days.

[0078] Among them, the precision products of various GNSS data analysis centers are usually calculated and provided on a daily basis, which may lead to daily boundary effects between adjacent days. This effect manifests as a step-like jump in the time difference series, posing a major challenge to extracting the gravity frequency shift by determining the slope of the time difference series. In addition, the receiver clock error solved by PPP-TFT includes not only the gravity frequency shift, but also the clock frequency shift, hardware delay error, unmodeled error, and other noise, further complicating the extraction results. In addition, the observation conditions change every day. Therefore, it is necessary to process the observation data of each day separately to obtain the receiver clock error series. Then, the results of the entire observation period are summarized according to the weight of the receiver clock error series.

[0079] Specific methods such as Figure 4 As shown in the figure: PPP-TFT processing is performed on daily observation data to obtain the receiver clock difference series for that day, that is, the time difference between the station clock and the IGS time reference clock; the receiver clock difference series is converted into a relative frequency difference series, where the inter-epoch difference of the receiver clock difference series is involved, which helps to mitigate some hardware delay errors, unmodeled errors and other noises; the relative frequency difference series is preprocessed by removing outliers and appropriate interpolation; a linear fit is performed on the relative frequency difference series, and the slope is treated as a frequency drift and removed; the average value of the processed relative frequency difference series is calculated as the relative frequency difference between the station clock and the IGS time reference clock for that day; the weighted average value of the relative frequency difference of each day in the current observation period is calculated to obtain the overall relative frequency difference of the observation period; the difference between the relative frequency differences before and after the clock transfer is calculated to obtain the gravity frequency shift of the two stations; the gravity potential difference between the two stations is determined using the gravity frequency shift equation.

[0080] From this we can see that if Figure 5 The frequency instability of the two observation periods is expressed as the modified Allan deviation, as shown in Figure 4 As shown in the upper left corner, it shows that the frequency instability of the two observation periods is very similar. During LTFS, the relative frequency difference between the station clock and the IGS reference clock is (-4540.05±5.34)×10 -16 , in JTFS, the relative frequency difference between the station clock and the IGS reference clock is (-3196.43±12.06)×10 -16 The results show that the gravity frequency shift between the two stations is (-1343.62±13.19)×10 -16 Therefore, the calculated gravity potential difference between the two stations is 12075.9±118.5m 2 / s 2 Compared with the EIGEN-6C4 global gravity field model, the gravity potential difference deviates from the model value by -80.5m. 2 / s 2Therefore, the present invention effectively reduces the complexity of gravity potential difference measurement operation, improves data utilization, and enhances measurement flexibility.

[0081] According to an embodiment of the present invention, a method for measuring gravity potential difference using a GNSS carrier phase single clock is proposed. A first relative frequency difference is determined based on a first receiver clock difference sequence of a target atomic clock at a first station relative to a reference clock during a target observation period, and a second relative frequency difference is determined based on a second receiver clock difference sequence of a target atomic clock at a second station relative to the reference clock during the target observation period. The difference between the first relative frequency difference and the second relative frequency difference is then used to determine the gravity frequency shift of the target atomic clock between the first station and the second station. The gravity potential difference between the first station and the second station, measured based on the GNSS carrier phase single clock, is then determined based on the gravity frequency shift, effectively improving the accuracy and flexibility of measuring gravity potential difference. This solves the problems in related technologies such as extremely high satellite data accuracy requirements, susceptibility to errors, or reliance on the number of satellites in common view, which limits long-distance applications and reduces the accuracy and flexibility of measuring gravity potential difference.

[0082] Next, a device for measuring gravity potential difference using a single GNSS carrier phase clock according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0083] Figure 6 The present invention is a block diagram of a device for measuring gravity potential difference using a single GNSS carrier phase clock.

[0084] like Figure 6 As shown, the device 10 for measuring gravity potential difference using a single GNSS carrier phase clock includes: a first acquisition module 100 , a second acquisition module 200 and a measurement module 300 .

[0085] Specifically, the first acquisition module 100 is used to obtain a first receiver clock difference sequence of the target atomic clock at the first measuring station relative to the reference clock during the target observation period, and determine a first relative frequency difference of the target atomic clock relative to the reference clock based on the first receiver clock difference sequence.

[0086] The second acquisition module 200 is used to obtain a second receiver clock difference sequence of the target atomic clock of the second measuring station relative to the reference clock during the target observation period, and determine a second relative frequency difference of the target atomic clock relative to the reference clock based on the second receiver clock difference sequence.

[0087] The measurement module 300 is used to determine the gravity frequency shift of the target atomic clock between the first measurement station and the second measurement station based on the difference between the first relative frequency difference and the second relative frequency difference, so as to determine the gravity potential difference between the first measurement station and the second measurement station based on the global navigation satellite system GNSS carrier phase single clock measurement according to the gravity frequency shift.

[0088] Optionally, in one embodiment of the present invention, the first acquisition module 100 includes: an acquisition unit, a conversion unit, a first determination unit, a second determination unit, and a third determination unit.

[0089] The acquisition unit is used to acquire the daily initial receiver clock difference sequence of the target atomic clock of the first measuring station relative to the reference clock during the target observation period.

[0090] The conversion unit is used to convert the initial receiver clock difference sequence into an initial relative frequency difference sequence, and perform data processing on the initial relative frequency difference sequence to obtain a processed relative frequency difference sequence.

[0091] The first determining unit is configured to determine an initial relative frequency difference between the target atomic clock and the reference clock according to a mean value of the processed relative frequency difference sequence.

[0092] The second determining unit is configured to determine a weight of a mean value of the processed relative frequency difference sequence based on the frequency stability of the initial relative frequency difference.

[0093] The third determining unit is configured to determine a first relative frequency difference of the target atomic clock of the first measuring station relative to the reference clock within the target observation period based on a weight of the mean value of the processed relative frequency difference sequence.

[0094] Optionally, in one embodiment of the present invention, the third determining unit includes: a first determining subunit and a second determining subunit.

[0095] The first determining subunit is configured to determine a weighted average of the daily relative frequency differences between the target atomic clock and the reference clock at the first measuring station during the target observation period based on the weight of the mean of the processed relative frequency difference sequence.

[0096] The second determining subunit is configured to determine a first relative frequency difference of a target atomic clock at a first measuring station relative to a reference clock within a target observation period according to a weighted average value of the relative frequency differences each day.

[0097] Optionally, in one embodiment of the present invention, the conversion unit includes: a first processing subunit and a second processing subunit.

[0098] The first processing subunit is configured to perform data preprocessing on the initial relative frequency difference sequence by removing outliers and performing target interpolation to obtain a preprocessed relative frequency difference sequence.

[0099] The second processing subunit is configured to perform linear fitting on the preprocessed relative frequency difference sequence to obtain a processed relative frequency difference sequence.

[0100] Optionally, in one embodiment of the present invention, the calculation formula of gravity frequency shift is:

[0101]

[0102] Where Δf PQ / f0 is the target gravity frequency shift, is the first relative frequency difference, is the second relative frequency difference, P is the first measuring station, and Q is the second measuring station.

[0103] Optionally, in one embodiment of the present invention, the calculation formula of the gravity potential difference is:

[0104] ΔW PQ =-c 2 Δf PQ / f0

[0105] Where ΔW PQ is the gravitational potential difference, c is the speed of light in vacuum, Δf PQ / f0 is the target gravity frequency shift.

[0106] It should be noted that the above explanation of the embodiment of the method for measuring gravity potential difference using a GNSS carrier phase single clock is also applicable to the device for measuring gravity potential difference using a GNSS carrier phase single clock in this embodiment, and will not be repeated here.

[0107] According to an embodiment of the present invention, a device for measuring gravity potential difference using a GNSS carrier phase single clock can determine a first relative frequency difference based on a first receiver clock difference sequence of a target atomic clock at a first station relative to a reference clock during a target observation period, and a second relative frequency difference based on a second receiver clock difference sequence of a target atomic clock at a second station relative to the reference clock during the target observation period. The device can then use the difference between the first relative frequency difference and the second relative frequency difference to determine the gravity frequency shift of the target atomic clock between the first station and the second station, thereby determining the gravity potential difference between the first station and the second station based on the GNSS carrier phase single clock measurement based on the gravity frequency shift. This effectively improves the accuracy and flexibility of measuring gravity potential difference. This solves the problems in related technologies such as extremely high satellite data accuracy requirements, susceptibility to errors, or reliance on the number of common-view satellites, which limits long-distance applications and reduces the accuracy and flexibility of measuring gravity potential difference.

[0108] Figure 7 This is a schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. The electronic device may include:

[0109] Memory 701 , processor 702 , and computer programs stored in the memory 701 and executable on the processor 702 .

[0110] When the processor 702 executes the program, the method for measuring gravity potential difference using a single GNSS carrier phase clock provided in the above embodiment is implemented.

[0111] Furthermore, the electronic device further includes:

[0112] The communication interface 703 is used for communication between the memory 701 and the processor 702 .

[0113] The memory 701 is used to store computer programs that can be run on the processor 702 .

[0114] The memory 701 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0115] If the memory 701, processor 702, and communication interface 703 are implemented independently, the communication interface 703, memory 701, and processor 702 can be connected to each other via a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 7 Only one thick line is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0116] Optionally, in a specific implementation, if the memory 701, the processor 702 and the communication interface 703 are integrated on a chip, the memory 701, the processor 702 and the communication interface 703 can communicate with each other through an internal interface.

[0117] The processor 702 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present invention.

[0118] This embodiment further provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the method for measuring gravity potential difference using a single GNSS carrier phase clock is implemented as described above.

[0119] This embodiment further provides a computer program product, including a computer program. When the computer program is executed, it is used to implement the above method for measuring gravity potential difference using a GNSS carrier phase single clock.

[0120] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0121] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "N" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0122] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or N executable instructions for implementing a custom logical function or step of a process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may be performed out of the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention pertain.

[0123] The logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (e.g., a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device). For purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include the following: an electrical connection with one or N wires (electronic devices), a portable computer disk cartridge (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disc read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program can be obtained electronically by optically scanning the paper or other medium and then editing, interpreting or processing it in other suitable ways as necessary, and then storing it in a computer memory.

[0124] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiment, the N steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, it can be implemented using any one or a combination of the following technologies known in the art: a discrete logic circuit having logic gate circuits for implementing logical functions on data signals, an application-specific integrated circuit having suitable combinational logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0125] Those skilled in the art will understand that all or part of the steps in the method of the above embodiment can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiment.

[0126] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing module, or each unit may exist physically separately, or two or more units may be integrated into a single module. The aforementioned integrated modules may be implemented in the form of hardware or in the form of software functional modules. If the integrated modules are implemented in the form of software functional modules and sold or used as independent products, they may also be stored in a computer-readable storage medium.

[0127] The storage medium mentioned above may be a read-only memory, a magnetic disk, or an optical disk, etc. Although the embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and are not to be construed as limiting the present invention. Persons skilled in the art may make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for measuring gravity potential difference using a single GNSS carrier phase clock, characterized in that: The following steps are involved: Acquire a first receiver clock difference sequence of a target atomic clock at a first measuring station relative to a reference clock during a target observation period, and determine a first relative frequency difference of the target atomic clock relative to the reference clock based on the first receiver clock difference sequence; obtaining a second receiver clock difference sequence of the target atomic clock at the second measuring station relative to the reference clock during the target observation period, and determining a second relative frequency difference of the target atomic clock relative to the reference clock based on the second receiver clock difference sequence; Based on the difference between the first relative frequency difference and the second relative frequency difference, a gravitational frequency shift of the target atomic clock between the first station and the second station is determined, so as to determine the gravitational potential difference between the first station and the second station based on the global navigation satellite system GNSS carrier phase single clock measurement according to the gravitational frequency shift.

2. The method according to claim 1, characterized in that The determining, according to the first receiver clock difference sequence, a first relative frequency difference of the target atomic clock relative to the reference clock, comprises: Acquire a daily initial receiver clock difference sequence of the target atomic clock of the first measuring station relative to the reference clock during the target observation period; Converting the initial receiver clock difference sequence into an initial relative frequency difference sequence, and performing data processing on the initial relative frequency difference sequence to obtain a processed relative frequency difference sequence; determining an initial relative frequency difference between the target atomic clock and the reference clock according to a mean value of the processed relative frequency difference sequence; determining a weight of a mean value of the processed relative frequency difference sequence based on a frequency stability of the initial relative frequency difference; Based on the weight of the mean of the processed relative frequency difference sequence, a first relative frequency difference of the target atomic clock of the first measuring station relative to the reference clock within the target observation period is determined.

3. The method according to claim 2, characterized in that Determining a first relative frequency difference of the target atomic clock at the first measuring station relative to the reference clock within the target observation period based on the weight of the mean of the processed relative frequency difference sequence includes: determining a weighted average of the daily relative frequency differences between the target atomic clock and the reference clock at the first station during the target observation period based on a weight of the mean of the processed relative frequency difference sequence; A first relative frequency difference of the target atomic clock of the first measuring station relative to the reference clock within the target observation period is determined according to a weighted average of the relative frequency differences of each day.

4. The method according to claim 2, characterized in that The performing data processing on the initial relative frequency difference sequence to obtain a processed relative frequency difference sequence includes: performing data preprocessing on the initial relative frequency difference sequence by removing outliers and performing target interpolation to obtain a preprocessed relative frequency difference sequence; The pre-processed relative frequency difference sequence is linearly fitted to obtain the processed relative frequency difference sequence.

5. The method according to claim 1, wherein The calculation formula of the gravity frequency shift is: Where Δf PQ / f0 is the target gravity frequency shift, is the first relative frequency difference, is the second relative frequency difference, P is the first measuring station, and Q is the second measuring station.

6. The method according to claim 5, characterized in that The calculation formula of the gravity potential difference is: ΔW PQ =-c 2 ·Δf PQ / f0 Where ΔW PQ is the gravitational potential difference, c is the speed of light in vacuum, Δf PQ / f0 is the target gravity frequency shift.

7. A device for measuring gravity potential difference using a single GNSS carrier phase clock, characterized in that: include: a first acquisition module, configured to acquire a first receiver clock difference sequence of a target atomic clock at a first measuring station relative to a reference clock during a target observation period, and determine a first relative frequency difference of the target atomic clock relative to the reference clock based on the first receiver clock difference sequence; a second acquisition module, configured to acquire a second receiver clock difference sequence of the target atomic clock at a second measuring station relative to the reference clock during the target observation period, and determine a second relative frequency difference of the target atomic clock relative to the reference clock based on the second receiver clock difference sequence; A measurement module is configured to determine a gravitational frequency shift of the target atomic clock between the first measuring station and the second measuring station based on a difference between the first relative frequency difference and the second relative frequency difference, so as to determine a gravitational potential difference between the first measuring station and the second measuring station based on a global navigation satellite system (GNSS) carrier phase single clock measurement according to the gravitational frequency shift.

8. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement a method for determining gravity potential difference using a GNSS carrier phase single clock as described in any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement a method for measuring gravity potential difference using a GNSS carrier phase single clock as described in any one of claims 1 to 6.

10. A computer program product comprising a computer program, characterized in that The computer program is executed by a processor to implement the method for measuring gravity potential difference using a GNSS carrier phase single clock as described in any one of claims 1 to 6.

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