Satellite navigation signal antenna phase center calibration method and system

Abstract

The application provides a satellite navigation signal antenna phase center calibration method and system, comprising: satellite inter-satellite link data is used for satellite precise clock difference estimation, and high-precision satellite clock difference of the inter-satellite link is obtained; the satellite inter-satellite link clock difference is fitted with a polynomial model, and the satellite inter-satellite link clock difference model coefficients, including clock difference deviation, clock speed and clock drift, are determined; the satellite inter-satellite link clock difference model is used to constrain the satellite clock difference parameters, the random walk estimation is carried out on the clock difference random term, the simplified dynamic orbit determination principle is used, the satellite orbit and the navigation signal antenna phase center deviation are jointly solved, and the on-orbit calibration of the satellite navigation signal (L band) antenna phase center deviation is realized. The method relieves the problem that the satellite antenna phase center deviation is related to the clock difference parameters, guarantees the accuracy of the satellite antenna phase center deviation correction, and supports the satellite precise orbit determination and the precise positioning service.

Description

Technical Field

[0001] This invention relates to the field of satellite positioning and navigation technology, and in particular to a method and system for calibrating the phase center of a satellite navigation signal antenna. Background Technology

[0002] In precise orbit determination of navigation satellites, the reference point for the dynamic model is generally the satellite's center of mass, and the solution parameters for precise orbit determination are also the position of the satellite's center of mass. Various observations measure the distance between the signal transmitting antenna and the signal receiving antenna. For L-band satellite-to-ground observations, this is the distance from the phase center of the satellite antenna to the phase center of the ground receiver antenna. The phase center offset (PCO) of the navigation satellite antenna not only affects the satellite's orbit determination accuracy but also has a systematic impact on the calculation of the reference frame scale. Therefore, accurate satellite PCO information is crucial for high-precision applications of navigation satellites. Typically, navigation satellite manufacturers provide ground calibration values ​​for the PCO of each satellite. However, severe vibrations during satellite launch, the deployment status of solar panels after entering orbit, and mass loss during the orbit insertion and operational phases can all cause the PCO value to deviate from the ground calibration value. Furthermore, relevant departments may not always be able to promptly release satellite PCO parameter information. Therefore, it is necessary to perform on-orbit calibration of the navigation satellite antenna PCO value using measured data.

[0003] During PCO on-orbit calibration, the small variation range of the nadir angle between the satellite and the ground station when using L-band satellite-to-ground observations results in a strong correlation between the L-band Z-axis PCO and the satellite clock error, leading to low estimation accuracy of the Z-direction PCO. To address this issue, there is an urgent need to propose a satellite navigation signal antenna phase center calibration method that can improve the estimation accuracy of the Z-direction PCO, thereby enhancing the accuracy of the satellite observation model. This is of great significance for precise orbit determination and high-precision positioning of navigation satellites. Summary of the Invention

[0004] This invention provides a method and system for calibrating the phase center of a satellite navigation signal antenna, in order to overcome the deficiencies existing in the prior art.

[0005] In a first aspect, the present invention provides a method for calibrating the phase center of a satellite navigation signal antenna, comprising:

[0006] Based on the least squares principle, satellite precise clock bias estimation is performed using inter-satellite link data to obtain inter-satellite link satellite clock bias.

[0007] A polynomial model was fitted to the high-precision satellite clock bias of the inter-satellite link to determine the inter-satellite link clock bias model for different satellites;

[0008] By applying constraints to the satellite clock bias parameters using the inter-satellite link clock bias model, estimating the clock bias random term, and using the simplified dynamic orbit determination principle, the satellite orbit and navigation signal antenna phase center deviation are jointly calculated using ground station GNSS observation data to obtain the calibration results.

[0009] According to the present invention, a satellite navigation signal antenna phase center calibration method is provided, which is based on the least squares principle and uses inter-satellite link data to estimate the precise satellite clock bias and obtain the inter-satellite link satellite clock bias, including:

[0010] The observation equation after meta-normalization of the original observations of the inter-satellite link determined by satellites A and B is as follows:

[0011]

[0012] in, and The bidirectional one-way pseudorange observations transmitted from satellite A and received by satellite B, and transmitted from satellite B and received by satellite A, are normalized to... The observed value at time, and These are the position vectors of satellites B and A, respectively. The speed of light in a vacuum. and These are the satellite clock differences for satellites B and A at the corresponding times. and These represent the inter-satellite link reception delay and transmission delay for the corresponding satellites, respectively. and To correct system errors, and This includes unmodeled errors and observation noise;

[0013] After normalizing the observation equations, the difference is taken to obtain the orbitless combined observations of the inter-satellite links:

[0014]

[0015] Using inter-satellite link orbitless combined observations, we perform network-wide adjustment and estimate satellite precise clock errors based on inter-satellite link data.

[0016] According to the satellite navigation signal antenna phase center calibration method provided by the present invention, a polynomial model fitting is performed on the high-precision satellite clock bias of the inter-satellite link to determine the inter-satellite link clock bias model for different satellites, including:

[0017] Determine the inter-satellite link clock bias model for:

[0018]

[0019] in, , and Reference times Clock deviation, clock speed, and clock drift. For the random term of clock bias;

[0020] Based on the inter-satellite link clock bias model, a polynomial fit is performed on the satellite precision clock bias obtained from the inter-satellite link data to obtain the clock bias, clock speed and clock drift corresponding to each satellite.

[0021] According to the present invention, a satellite navigation signal antenna phase center calibration method applies constraints to satellite clock bias parameters using the inter-satellite link clock bias model and estimates the clock bias random term, including:

[0022] Determine L-band pseudorange and carrier observation equation They are respectively:

[0023]

[0024]

[0025] in, These represent the serial numbers of the satellite, receiver, and frequency, respectively. and They represent the first satellites at various frequencies to receiver L-band pseudorange and carrier observations; and These represent the satellite's centroid vector and the receiver antenna's phase center vector, respectively. Correction for the phase center of the satellite antenna; The speed of light; and These represent satellite clock bias and receiver clock bias, respectively. and These represent tropospheric delay and ionospheric delay, respectively. For frequency wavelength, For the ambiguity parameters corresponding to the frequency; and Indicates other systematic errors; and These represent the measurement noise of pseudorange and carrier phase observations, respectively.

[0026] Assume the phase center deviation (PCO) vector of an L-band antenna for a satellite in a fixed-plane system is... The antenna phase center deviation is corrected in the inertial frame as follows: :

[0027]

[0028] in, , , Let be the unit vector of the star-fixed coordinate axis in the inertial frame, specifically expressed as:

[0029]

[0030] in, The unit vector in the satellite-sun direction. This is the satellite position vector;

[0031] The correction amount of satellite-to-ground distance caused by the phase center deviation of any satellite's antenna for:

[0032]

[0033] in, Let be the unit direction vector from the satellite to the ground station in the inertial frame. The partial derivative of the L-band observation with respect to the PCO parameters is expressed as:

[0034]

[0035] After obtaining the partial derivatives of the satellite PCO parameters, the PCO is used as an estimated parameter in the precise orbit determination data processing, and is solved together with the satellite orbit parameters. In each orbit determination arc segment, the PCO is estimated as a constant.

[0036] According to the present invention, a method for calibrating the phase center of a satellite navigation signal antenna is provided. Based on the simplified dynamic orbit determination principle, the method uses GNSS observation data from ground stations to jointly calculate the deviation between the satellite orbit and the phase center of the navigation signal antenna, and obtains the calibration result, including:

[0037] The clock bias of each satellite was obtained using an inter-satellite link clock bias model. , and For each epoch, the satellite clock bias excluding the random term is calculated using the clock bias model formula as a priori value. A random walk estimation is performed on the random term, and constraints are imposed between epochs.

[0038]

[0039] in, and These represent the clock difference random terms in two adjacent epochs. Indicates the error per unit weight. This represents the constraint on the random term of clock bias between adjacent epochs, and its value is adjusted according to the stability of the satellite clock.

[0040] Secondly, the present invention also provides a satellite navigation signal antenna phase center calibration system, comprising:

[0041] The estimation module is used to estimate the precise clock bias of satellites based on the least squares principle and using inter-satellite link data to obtain the inter-satellite link satellite clock bias.

[0042] The fitting module is used to perform polynomial model fitting on the high-precision satellite clock difference of the inter-satellite link to determine the inter-satellite link clock difference model for different satellites.

[0043] The calibration module is used to impose constraints on the satellite clock bias parameters using the inter-satellite link clock bias model, estimate the clock bias random term, and, based on the simplified dynamic orbit determination principle, jointly calculate the satellite orbit and navigation signal antenna phase center deviation using ground station GNSS observation data to obtain the calibration result.

[0044] According to the satellite navigation signal antenna phase center calibration system provided by the present invention, the estimation module is specifically used for:

[0045] The observation equation after meta-normalization of the original observations of the inter-satellite link determined by satellites A and B is as follows:

[0046]

[0047] in, and The bidirectional one-way pseudorange observations transmitted from satellite A and received by satellite B, and transmitted from satellite B and received by satellite A, are normalized to... The observed value at time, and These are the position vectors of satellites B and A, respectively. The speed of light in a vacuum. and These are the satellite clock differences for satellites B and A at the corresponding times. and These represent the inter-satellite link reception delay and transmission delay for the corresponding satellites, respectively. and To correct system errors, and This includes unmodeled errors and observation noise;

[0048] After normalizing the observation equations, the difference is taken to obtain the orbitless combined observations of the inter-satellite links:

[0049]

[0050] Using inter-satellite link orbitless combined observations, we perform network-wide adjustment and estimate satellite precise clock errors based on inter-satellite link data.

[0051] Thirdly, the present invention also provides an electronic device, including 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 the satellite navigation signal antenna phase center calibration method as described above.

[0052] Fourthly, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the satellite navigation signal antenna phase center calibration method as described above.

[0053] Fifthly, the present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the satellite navigation signal antenna phase center calibration method as described above.

[0054] The satellite navigation signal antenna phase center calibration method and system provided by this invention addresses the problem of low z-axis PCO estimation accuracy due to the strong correlation between satellite clock bias parameters and z-axis PCO parameters during on-orbit calibration of satellite antenna phase center deviation. Utilizing the high accuracy and decoupling of inter-satellite link clock bias with orbital parameters, a method is constructed to constrain satellite clock bias parameters using precise inter-satellite link clock bias and to calibrate the satellite antenna phase center deviation on-orbit in a simple manner. Applying the satellite antenna phase center deviation calibration method provided by this invention can obtain higher-precision satellite L-band antenna phase center deviations, providing a foundation for related research and effectively improving orbit accuracy during precise satellite orbit determination. Attached Figure Description

[0055] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0056] Figure 1 This is one of the flowcharts illustrating the satellite navigation signal antenna phase center calibration method provided by the present invention;

[0057] Figure 2 This is the second flowchart illustrating the satellite navigation signal antenna phase center calibration method provided by the present invention;

[0058] Figure 3 This is a schematic diagram of the satellite navigation signal antenna phase center calibration system provided by the present invention;

[0059] Figure 4This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0061] Figure 1 This is one of the flowcharts illustrating the satellite navigation signal antenna phase center calibration method provided in this embodiment of the invention, such as... Figure 1 As shown, it includes:

[0062] Step 100: Based on the least squares principle, use inter-satellite link data to estimate the precise satellite clock bias and obtain the inter-satellite link satellite clock bias;

[0063] Step 200: Perform polynomial model fitting on the high-precision satellite clock bias of the inter-satellite link to determine the inter-satellite link clock bias model for different satellites;

[0064] Step 300: Apply constraints to the satellite clock bias parameters using the inter-satellite link clock bias model, estimate the clock bias random term, and based on the simplified dynamic orbit determination principle, use ground station GNSS observation data to jointly calculate the satellite orbit and navigation signal antenna phase center deviation to obtain the calibration result.

[0065] Specifically, such as Figure 2 As shown, the basic implementation process of this invention is as follows: First, using inter-satellite link observation data, precise satellite clock bias estimation based on inter-satellite links is performed to calculate high-precision satellite clock bias for inter-satellite links; second, polynomial fitting is performed on the obtained inter-satellite link satellite clock bias to determine the clock offset, clock velocity, and clock drift parameters corresponding to the clock bias model of each satellite; finally, prior constraints are applied to the satellite clock bias parameters, and random term parameters are estimated. Based on the simplified dynamic orbit determination principle, ground station GNSS observation data is used to jointly calculate the phase center deviation of the satellite orbit and navigation signal antenna to achieve on-orbit calibration of the phase center deviation of the satellite navigation signal antenna.

[0066] In one embodiment, the specific implementation process includes the following steps:

[0067] Step 1: Estimate satellite clock bias using inter-satellite link observation data based on the least squares principle.

[0068] The observation equations after meta-normalization of the original observations from the BeiDou-3 inter-satellite links are as follows:

[0069] in, and The bidirectional one-way pseudorange observations transmitted from satellite A and received by satellite B, and transmitted from satellite B and received by satellite A, are normalized to... The observed value at time, and These are the position vectors of satellites B and A, respectively. The speed of light in a vacuum. and These are the satellite clock differences for satellites B and A at the corresponding times. and These represent the inter-satellite link reception delay and transmission delay for the corresponding satellites, respectively. and To correct system errors, and This includes unmodeled errors and observation noise.

[0070] The orbital information can be eliminated by subtracting the above normalized data, resulting in the following orbit-free inter-satellite link observations:

[0071]

[0072] This includes the transmission and reception delay difference between the inter-satellite link equipment of satellites A and B, which is strongly correlated with the satellite clock error parameters and cannot be solved simultaneously, so it needs to be calibrated in advance.

[0073] By utilizing the orbitless combined observations of inter-satellite links and performing network-wide adjustment, precise satellite clock error estimation based on inter-satellite link data can be achieved.

[0074] Step 2: Perform polynomial fitting on the obtained inter-satellite link satellite clock bias to determine the clock bias, clock speed, and clock drift parameters corresponding to the clock bias model of each satellite.

[0075] Inter-satellite link clock bias model for:

[0076]

[0077] in, , and Reference times Clock deviation, clock speed, and clock drift. For the random term of clock bias.

[0078] For the precise clock bias of satellites obtained based on inter-satellite link data, polynomial fitting is performed according to the clock bias model to obtain the clock bias, clock speed and clock drift parameters corresponding to each satellite.

[0079] Step 3: Combining the satellite clock bias model from Step 2, apply prior constraints to the satellite clock bias parameters and estimate the random term parameters. Based on the simplified dynamic orbit determination principle, use ground station GNSS observation data to jointly calculate the satellite orbit and navigation signal antenna phase center deviation.

[0080] L-band (satellite navigation signal) pseudorange and carrier observation equation It can be represented as:

[0081]

[0082]

[0083] in, These represent the serial numbers of the satellite, receiver, and frequency, respectively. and They represent the first satellites at various frequencies to receiver L-band pseudorange and carrier observations; and These represent the satellite's centroid vector and the receiver antenna's phase center vector, respectively. Correction for the phase center of the satellite antenna; The speed of light; and These represent satellite clock bias and receiver clock bias, respectively. and These represent tropospheric delay and ionospheric delay, respectively. For frequency wavelength, For the ambiguity parameters corresponding to the frequency; and Indicates other systematic errors; and These represent the measurement noise of pseudorange and carrier phase observations, respectively.

[0084] Assume the PCO vector of a satellite's L-band antenna in a fixed-plane system is Then, the phase center deviation of this antenna in the inertial frame is corrected as follows:

[0085]

[0086] in, , , Let be the unit vector of the star-fixed coordinate axis in the inertial frame, which can be specifically expressed as:

[0087]

[0088] in, The unit vector in the satellite-sun direction. This is the satellite position vector.

[0089] The correction amount for satellite-to-ground distance caused by the phase center deviation of a satellite's antenna. for,

[0090]

[0091] in, Let be the unit direction vector from the satellite to the ground station in the inertial frame. Then, the partial derivative of the L-band observation with respect to the PCO parameter can be expressed as:

[0092]

[0093] After obtaining the partial derivatives of the satellite PCO parameters, the PCO can be used as an estimated parameter in the precise orbit determination data processing, and solved together with the satellite orbit and other parameters. In each orbit determination arc segment, the PCO is estimated as a constant.

[0094] During the calculation, the satellite clock bias model is used to obtain the clock bias of each satellite. , and The parameters are calculated using the clock bias model formula for each epoch, and the satellite clock bias (excluding the random term) for the current epoch is used as the prior value. Random walk estimation is performed on the random term, and constraints are applied between epochs.

[0095]

[0096] In the above formula, and These represent the clock difference random terms in two adjacent epochs. Indicates the error per unit weight. This represents the constraint on the random term of clock bias between adjacent epochs, and its value should be adjusted according to the stability of the satellite clock.

[0097] The satellite navigation signal antenna phase center calibration system provided by the present invention is described below. The satellite navigation signal antenna phase center calibration system described below can be referred to in correspondence with the satellite navigation signal antenna phase center calibration method described above.

[0098] Figure 3 This is a schematic diagram of the satellite navigation signal antenna phase center calibration system provided in an embodiment of the present invention, as shown below. Figure 3 As shown, it includes: estimation module 31, fitting module 32, and calibration module 33, wherein:

[0099] The estimation module 31 is used to estimate the precise satellite clock bias based on the least squares principle using inter-satellite link data, and obtain the inter-satellite link satellite clock bias; the fitting module 32 is used to perform polynomial model fitting on the high-precision inter-satellite link satellite clock bias, and determine the inter-satellite link clock bias model for different satellites; the calibration module 33 is used to apply constraints to the satellite clock bias parameters using the inter-satellite link clock bias model, estimate the clock bias random term, and, based on the simplified dynamic orbit determination principle, use ground station GNSS observation data to jointly solve the satellite orbit and navigation signal antenna phase center deviation, and obtain the calibration result.

[0100] Figure 4 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 4 As shown, the electronic device may include a processor 410, a communication interface 420, a memory 430, and a communication bus 440. The processor 410, communication interface 420, and memory 430 communicate with each other via the communication bus 440. The processor 410 can call logical instructions in the memory 430 to execute a satellite navigation signal antenna phase center calibration method. This method includes: estimating the precise satellite clock bias using inter-satellite link data based on the least squares principle to obtain the inter-satellite link satellite clock bias; fitting a polynomial model to the high-precision inter-satellite link satellite clock bias to determine the inter-satellite link clock bias model for different satellites; applying constraints to the satellite clock bias parameters using the inter-satellite link clock bias model, estimating the clock bias random term, and, based on the simplified dynamic orbit determination principle, jointly calculating the satellite orbit and navigation signal antenna phase center deviation using ground station GNSS observation data to obtain the calibration result.

[0101] Furthermore, the logical instructions in the aforementioned memory 430 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0102] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the satellite navigation signal antenna phase center calibration method provided by the above methods. The method includes: estimating the precise satellite clock bias using inter-satellite link data based on the least squares principle to obtain the inter-satellite link satellite clock bias; fitting a polynomial model to the high-precision inter-satellite link satellite clock bias to determine the inter-satellite link clock bias model for different satellites; applying constraints to the satellite clock bias parameters using the inter-satellite link clock bias model, estimating the clock bias random term, and, based on the simplified dynamic orbit determination principle, jointly calculating the satellite orbit and navigation signal antenna phase center deviation using ground station GNSS observation data to obtain the calibration result.

[0103] In another aspect, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon. When executed by a processor, the computer program implements the satellite navigation signal antenna phase center calibration method provided by the above methods. The method includes: estimating the precise satellite clock bias using inter-satellite link data based on the least squares principle to obtain the inter-satellite link satellite clock bias; fitting a polynomial model to the high-precision inter-satellite link satellite clock bias to determine the inter-satellite link clock bias model for different satellites; applying constraints to the satellite clock bias parameters using the inter-satellite link clock bias model, estimating the clock bias random term, and, based on the simplified dynamic orbit determination principle, jointly calculating the satellite orbit and navigation signal antenna phase center deviation using ground station GNSS observation data to obtain the calibration result.

[0104] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0105] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0106] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for calibrating a phase center of a satellite navigation signal antenna, characterized in that, The method comprises the following steps: Based on the least square principle, the satellite precise clock difference is estimated by using the satellite inter-satellite link data to obtain the inter-satellite link satellite clock difference; The inter-satellite link satellite clock difference is fitted by a polynomial model to determine the inter-satellite link clock difference model of different satellites; The satellite clock difference parameters are constrained by using the inter-satellite link clock difference model, the clock difference random term is estimated, the satellite orbit and the navigation signal antenna phase center offset are jointly solved based on the simplified dynamic orbit determination principle by using the ground station GNSS observation data, and the calibration result is obtained; Based on the simplified dynamic orbit determination principle, the satellite orbit and the navigation signal antenna phase center offset are jointly solved by using the ground station GNSS observation data, and the calibration result is obtained, which comprises: Determining L-band pseudorange and carrier observation equations are: wherein, Nsat, Nrec, and Nf represent the serial numbers of the satellite, receiver and frequency, respectively, and Nsat, Nrec, and Nf represent the serial numbers of the satellite, receiver and frequency, respectively, and Nsat, Nrec, and Nf represent the serial numbers of the satellite, receiver and frequency, respectively, and Nsat, Nrec, and Nf represent the serial numbers of the satellite, receiver and frequency, respectively, and Nsat, Nrec, and Nf represent the serial numbers of the satellite, receiver and frequency, respectively, Nsat, Nrec, and Nf represent the serial numbers of the satellite, receiver and frequency, respectively, Nsat, Nrec, and Nf represent the serial numbers of the satellite, receiver and frequency, respectively, Nsat, Nrec, and Nf represent the serial numbers of the satellite, receiver and frequency, respectively, Nsat, Nrec, and Nf represent the serial numbers of the satellite, receiver and frequency, respectively, Nsat, Nrec, and Nf represent the serial numbers of the satellite, receiver and frequency, respectively, Nsat, Nrec, and Nf represent the serial numbers of the satellite, receiver and frequency, respectively, Nsat, Nrec, and Nf represent the serial numbers of the satellite, receiver and frequency, respectively, Nsat, Nrec, and Nf represent the serial numbers of the satellite, receiver and frequency, respectively, Nsat, Nrec, and Nf represent the serial numbers of the satellite, receiver and frequency, respectively, Nsat, Nrec, and Nf represent the serial numbers of the satellite, receiver and frequency, respectively, Nsat, Nrec, and Nf represent the serial numbers of the satellite, receiver and frequency, respectively, Nsat, Nrec, and Nf represent the serial numbers of the satellite, receiver and frequency, respectively, Assume that the phase center offset (PCO) vector of a satellite L-band antenna in the star-fixed system is Then the antenna phase center offset correction in the inertial system is : wherein , , is a unit vector of the star-fixed coordinate axis in the inertial system, and is specifically represented as: wherein, is a unit vector in the satellite-sun direction, is a satellite position vector; The correction of the slant range caused by the antenna phase center offset of any satellite is: where is the unit direction vector from the satellite to the ground station in the inertial frame, and the partial derivative of the L-band observations with respect to the PCO parameters is given by After obtaining the partial derivative of the satellite PCO parameter, the PCO is solved as a to-be-estimated parameter together with the satellite orbit parameter in the precise orbit determination data processing, and the PCO is estimated as a constant in each orbit determination arc segment.

2. The method of claim 1, wherein, Based on the least square principle, the satellite precise clock difference is estimated by using the satellite inter-satellite link data to obtain the inter-satellite link satellite clock difference, which comprises: The observation equation of the original observation value of the inter-satellite link determined by satellite A and satellite B after the epoch normalization is as follows: where and are the bi-directional one-way pseudo-range observations of satellite A transmitting to satellite B receiving and satellite B transmitting to satellite A receiving normalized to the observation time, and are the position vectors of satellites B, A, is the speed of light in vacuum, and are the satellite clock errors of satellites B, A at the corresponding time, and are the inter-satellite link receiving delays of satellite A and satellite B, and are the transmitting delays of satellite A and satellite B, and are the systematic error corrections, and are the un-modeled errors and observation noise; The orbit-free combined observation of the inter-satellite link is obtained by differencing the normalized observation equation: The inter-satellite link data-based satellite precise clock difference is estimated by using the orbit-free combined observation of the inter-satellite link for network adjustment.

3. The method of claim 1, wherein, The inter-satellite link satellite clock difference is fitted by a polynomial model to determine the inter-satellite link clock difference model of different satellites, which comprises: Determining inter-satellite link clock difference model For: wherein, , and are the clock bias, clock rate and clock drift at the reference time , is the stochastic term of the clock error; According to the inter-satellite link clock difference model, the polynomial fitting of the satellite precise clock difference obtained based on the inter-satellite link data is performed to obtain the clock offset, clock speed and clock drift corresponding to each satellite.

4. The method of claim 3, wherein, The satellite clock difference parameters are constrained by using the inter-satellite link clock difference model, the clock difference random term is estimated, the satellite orbit and the navigation signal antenna phase center offset are jointly solved based on the simplified dynamic orbit determination principle by using the ground station GNSS observation data, and the calibration result is obtained. The parameters of each satellite are obtained by using the clock difference model of inter-satellite link , and . The satellite clock difference without random term at the current epoch is calculated by using the clock difference model formula at each epoch as the prior value, and the random walk estimation is performed on the random term, and the constraint is applied between epochs. where, and denote the clock error random terms of the adjacent two ephemerides, denotes the unit weight error, denotes the constraint of the clock error random terms between adjacent ephemerides, which is adjusted according to the stability of the satellite clock.

5. A satellite navigation signal antenna phase center calibration system based on the satellite navigation signal antenna phase center calibration method according to any one of claims 1 to 4, characterized in that, It comprises: The estimation module is used for estimating the satellite precise clock difference based on the least square principle by using the satellite inter-satellite link data to obtain the inter-satellite link satellite clock difference; The fitting module is used for fitting the inter-satellite link satellite clock difference by a polynomial model to determine the inter-satellite link clock difference model of different satellites; The calibration module is used for constraining the satellite clock difference parameters by using the inter-satellite link clock difference model, estimating the clock difference random term, jointly solving the satellite orbit and the navigation signal antenna phase center offset based on the simplified dynamic orbit determination principle by using the ground station GNSS observation data, and obtaining the calibration result.

6. The satellite navigation signal antenna phase center calibration system of claim 5, wherein, The estimation module is specifically used for: The observation equation of the original observation value of the inter-satellite link determined by satellite A and satellite B after the epoch normalization is as follows: where and are the normalized to the observation of the bi-directional one-way pseudo-range observations of satellite A transmitting to satellite B receiving and satellite B transmitting to satellite A receiving respectively, and are the position vectors of satellite B and satellite A respectively, is the speed of light in vacuum, and are the satellite clock biases of satellite B and satellite A at the corresponding time respectively, and are the inter-satellite link receiving delays of satellite A and satellite B respectively, and are the transmitting delays of satellite A and satellite B respectively, and are the system error corrections, and are the un-modeled errors and observation noise. The orbit-free combined observation of the inter-satellite link is obtained by differencing the normalized observation equation: The inter-satellite link data-based satellite precise clock difference is estimated by using the orbit-free combined observation of the inter-satellite link for network adjustment.

7. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor executes the program to realize the satellite navigation signal antenna phase center calibration method in any one of claims 1 to 4.

8. A non-transitory computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to realize the satellite navigation signal antenna phase center calibration method in any one of claims 1 to 4.

9. A computer program product comprising a computer program, characterized in that, The computer program is executed by a processor to implement the satellite navigation signal antenna phase center calibration method according to any one of claims 1 to 4.

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