Reconvergence method and device for precise point positioning

Abstract

The invention provides a re-convergence method and device for precise point positioning, and the method comprises the steps: obtaining first GNSS measurement data of a current epoch and second GNSS measurement data of a previous effective epoch after a signal is recovered, and determining a difference age between the first GNSS measurement data and the second GNSS measurement data; if the differential age is not greater than the age threshold, performing inter-epoch differential positioning calculation according to the first GNSS measurement data and the second GNSS measurement data, and determining an estimated position of the receiver; according to the first GNSS measurement data, the second GNSS measurement data and the estimated position, determining an initial state parameter required by precise point positioning updating; the initial state parameter comprises a receiver position correction number, and the receiver position correction number is determined according to an estimated position; and according to the initial state parameter and a precise single-point positioning observation equation, carrying out filtering calculation processing, and determining the target position of the receiver. Thus, through inter-epoch differential positioning resolving processing, the accurate position of the receiver is determined, and therefore rapid reconvergence of the PPP can be achieved.

Description

Technical Field

[0001] The present application relates to the field of signal processing technology, and in particular to a re-convergence method and device for precise single-point positioning. Background Art

[0002] Precise Point Positioning (PPP) technology is a technology that achieves high-precision positioning through a single receiver. It has the advantages of portability, flexibility, low cost and wide operating range. It can provide high-precision positioning services for the majority of GNSS (Global Navigation Satellite System) users and has been widely used in many fields such as geodetic surveying.

[0003] Although satellite navigation resources have been greatly improved, PPP still has the problem of long convergence time. It usually takes about 20 minutes to achieve centimeter-level positioning results, which seriously restricts the application of PPP in high-precision positioning. Due to reasons such as satellite signal blocking, the signal will be lost, the carrier phase observation value will jump or be interrupted, and re-convergence is required. In complex scenarios, satellite signals are prone to frequent blocking problems, and the performance of PPP will be greatly reduced. Summary of the invention

[0004] In view of this, the purpose of the present application is to provide a re-convergence method and device for precise single-point positioning. The present application determines a relatively accurate receiver position through inter-epoch differential positioning solution processing, thereby achieving rapid re-convergence of PPP.

[0005] The present application provides a reconvergence method for precise point positioning, the reconvergence method comprising:

[0006] When the signal is restored, the first GNSS measurement data of the current epoch and the second GNSS measurement data of the previous valid epoch are obtained, and the differential age between the two is determined;

[0007] If the differential age is not greater than the age threshold, performing inter-epoch differential positioning solution according to the first GNSS measurement data and the second GNSS measurement data to determine the estimated position of the receiver; wherein the differential positioning solution includes inter-epoch pseudorange differential positioning solution and inter-epoch carrier phase differential positioning solution;

[0008] Determining initial state parameters required for precise point positioning update based on the first GNSS measurement data, the second GNSS measurement data, and the estimated position; the initial state parameters include a receiver position correction number, and the receiver position correction number is determined based on the estimated position;

[0009] According to the initial state parameters and the precise point positioning observation equation, filtering and solving are performed to determine the target position of the receiver.

[0010] Optionally, performing inter-epoch differential positioning solution according to the first GNSS measurement data and the second GNSS measurement data to determine the estimated position of the receiver includes:

[0011] Perform inter-epoch pseudorange differential positioning solution based on the first GNSS measurement data and the second GNSS measurement data to determine whether there is a first position of the receiver that meets the solution requirements;

[0012] If the first position exists, performing inter-epoch carrier phase differential positioning solution according to the first GNSS measurement data and the second GNSS measurement data to determine whether there is a second position of the receiver that meets the solution requirements;

[0013] If the first position exists but the second position does not exist, determining the first position as the estimated position;

[0014] If both the first position and the second position exist, the second position is determined as the estimated position.

[0015] Optionally, performing inter-epoch pseudorange differential positioning solution according to the first GNSS measurement data and the second GNSS measurement data to determine whether there is a first position of the receiver that meets the solution requirements includes:

[0016] For each of the target satellites, a first pseudorange undifferenced observation equation of a current epoch is determined according to the first GNSS measurement data, and a second pseudorange undifferenced observation equation of a previous valid epoch is determined according to the second GNSS measurement data;

[0017] According to the first pseudo-range non-difference observation equation and the second pseudo-range non-difference observation equation, for each of the target satellites, a pseudo-range single-difference observation equation is determined based on the pseudo-range non-difference observation equation between two epochs corresponding to the same target satellite by performing differential processing according to a preset differential rule. ;

[0018] One of the target satellites is used as a reference satellite, and the pseudo-range single-difference observation equation corresponding to the reference satellite and the pseudo-range single-difference observation equations corresponding to the remaining target satellites are subjected to a second difference process according to a preset difference rule to determine a pseudo-range double-difference model;

[0019] Constructing a first target matrix according to all pseudorange double-difference models;

[0020] Performing least squares parameter estimation based on the first target matrix, determining the first inter-epoch position difference and the first least squares parameter estimation index;

[0021] If the first least squares parameter estimation index is less than the first threshold, the first epoch position difference is the first epoch target position difference;

[0022] The historical position of the receiver determined according to the second GNSS measurement data is updated using the first inter-epoch target position difference to determine a first position of the receiver at a current epoch.

[0023] Optionally, if the first least squares parameter estimation index is not less than the first threshold, the first position is determined by the following steps:

[0024] Eliminate pseudorange observation values ​​that meet a first elimination condition in the first GNSS measurement data and the second GNSS measurement data;

[0025] If the total number of remaining pseudorange observation values ​​is not less than the first total number threshold, the iterative calculation of the first position is re-executed based on the remaining first GNSS measurement data and the second GNSS measurement data.

[0026] Optionally, performing inter-epoch carrier phase differential positioning solution according to the first GNSS measurement data and the second GNSS measurement data to determine whether there is a second position of the receiver that meets the solution requirements includes:

[0027] For each of the target satellites, a first carrier phase undifference observation equation of a current epoch is determined according to the first GNSS measurement data, and a second carrier phase undifference observation equation of a previous valid epoch is determined according to the second GNSS measurement data;

[0028] According to the first carrier phase non-difference observation equation and the second carrier phase non-difference observation equation, for each of the target satellites, a carrier phase single-difference observation equation is determined by performing differential processing according to a preset differential rule based on the carrier phase non-difference observation equation between two epochs corresponding to the same target satellite;

[0029] One of the target satellites is used as a reference satellite, and the carrier phase single-difference observation equation corresponding to the reference satellite and the carrier phase single-difference observation equations corresponding to the remaining target satellites are subjected to difference processing one by one according to a preset difference rule to determine a carrier phase double-difference model;

[0030] Constructing a second target matrix according to all carrier phase double difference models;

[0031] Performing least squares parameter estimation based on the second target matrix to determine the second epoch position difference and the second least squares parameter estimation index;

[0032] If the second least squares parameter estimation index is less than the second threshold, the second epoch position difference is the second epoch target position difference;

[0033] The historical position of the receiver determined according to the second GNSS measurement data is updated using the target position difference between the second epochs to determine the second position of the receiver in the current epoch.

[0034] Optionally, if the second least squares parameter estimation index is not less than the second threshold, the second position is determined by the following steps:

[0035] Eliminate carrier phase observation values ​​that meet a second elimination condition in the first GNSS measurement data and the second GNSS measurement data;

[0036] If the total number of remaining carrier phase observation values ​​is not less than the second total number threshold, the iterative calculation of the second position is re-executed based on the remaining first GNSS measurement data and the second GNSS measurement data.

[0037] The embodiment of the present application also provides a re-convergence device for precise single-point positioning, the re-convergence device comprising:

[0038] An acquisition module, used for acquiring the first GNSS measurement data of the current epoch and the second GNSS measurement data of the previous valid epoch after the signal is restored, and determining the differential age between the two;

[0039] A first determination module is used to perform inter-epoch differential positioning solution according to the first GNSS measurement data and the second GNSS measurement data to determine the estimated position of the receiver if the differential age is not greater than the age threshold; wherein the differential positioning solution includes inter-epoch pseudorange differential positioning solution and inter-epoch carrier phase differential positioning solution;

[0040] A second determination module is used to determine initial state parameters required for precise point positioning update according to the first GNSS measurement data, the second GNSS measurement data and the estimated position; the initial state parameters include a receiver position correction number, and the receiver position correction number is determined according to the estimated position;

[0041] The first processing module is used to perform filtering and solving processing according to the initial state parameters and the precise point positioning observation equation to determine the target position of the receiver.

[0042] Optionally, when the first determination module is used to perform inter-epoch differential positioning solution according to the first GNSS measurement data and the second GNSS measurement data to determine the estimated position of the receiver, the first determination module is used to:

[0043] Perform inter-epoch pseudorange differential positioning solution based on the first GNSS measurement data and the second GNSS measurement data to determine whether there is a first position of the receiver that meets the solution requirements;

[0044] If the first position exists, performing inter-epoch carrier phase differential positioning solution according to the first GNSS measurement data and the second GNSS measurement data to determine whether there is a second position of the receiver that meets the solution requirements;

[0045] If the first position exists but the second position does not exist, determining the first position as the estimated position;

[0046] If both the first position and the second position exist, the second position is determined as the estimated position.

[0047] Optionally, when the first determination module is used to perform inter-epoch pseudorange differential positioning solution according to the first GNSS measurement data and the second GNSS measurement data to determine whether there is a first position of the receiver that meets the solution requirements, the first determination module is used to:

[0048] For each of the target satellites, a first pseudorange undifferenced observation equation of a current epoch is determined according to the first GNSS measurement data, and a second pseudorange undifferenced observation equation of a previous valid epoch is determined according to the second GNSS measurement data;

[0049] According to the first pseudorange non-difference observation equation and the second pseudorange non-difference observation equation, for each of the target satellites, a pseudorange single-difference observation equation is determined by performing differential processing according to a preset differential rule based on the pseudorange non-difference observation equation between two epochs corresponding to the same target satellite;

[0050] One of the target satellites is used as a reference satellite, and the pseudo-range single-difference observation equation corresponding to the reference satellite and the pseudo-range single-difference observation equations corresponding to the remaining target satellites are subjected to a second difference process according to a preset difference rule to determine a pseudo-range double-difference model;

[0051] Constructing a first target matrix according to all pseudorange double-difference models;

[0052] Performing least squares parameter estimation based on the first target matrix, determining the first inter-epoch position difference and the first least squares parameter estimation index;

[0053] If the first least squares parameter estimation index is less than the first threshold, the first epoch position difference is the first epoch target position difference;

[0054] The historical position of the receiver determined according to the second GNSS measurement data is updated using the first inter-epoch target position difference to determine a first position of the receiver at a current epoch.

[0055] Optionally, the first determining module is further used for:

[0056] If the first least squares parameter estimation index is not less than a first threshold, the pseudorange observation values ​​satisfying the first elimination condition in the first GNSS measurement data and the second GNSS measurement data are eliminated;

[0057] If the total number of remaining pseudorange observation values ​​is not less than the first total number threshold, the iterative calculation of the first position is re-executed based on the remaining first GNSS measurement data and the second GNSS measurement data.

[0058] Optionally, when the first determination module is used to perform inter-epoch carrier phase differential positioning solution according to the first GNSS measurement data and the second GNSS measurement data to determine whether there is a second position of the receiver that meets the solution requirements, the first determination module is used to:

[0059] For each of the target satellites, a first carrier phase undifference observation equation of a current epoch is determined according to the first GNSS measurement data, and a second carrier phase undifference observation equation of a previous valid epoch is determined according to the second GNSS measurement data;

[0060] According to the first carrier phase non-difference observation equation and the second carrier phase non-difference observation equation, for each of the target satellites, a carrier phase single-difference observation equation is determined by performing differential processing according to a preset differential rule based on the carrier phase non-difference observation equation between two epochs corresponding to the same target satellite;

[0061] One of the target satellites is used as a reference satellite, and the carrier phase single-difference observation equation corresponding to the reference satellite and the carrier phase single-difference observation equations corresponding to the remaining target satellites are subjected to difference processing one by one according to a preset difference rule to determine a carrier phase double-difference model;

[0062] Constructing a second target matrix according to all carrier phase double difference models;

[0063] Performing least squares parameter estimation based on the second target matrix to determine the second epoch position difference and the second least squares parameter estimation index;

[0064] If the second least squares parameter estimation index is less than the second threshold, the second epoch position difference is the second epoch target position difference;

[0065] The historical position of the receiver determined according to the second GNSS measurement data is updated using the target position difference between the second epochs to determine the second position of the receiver in the current epoch.

[0066] Optionally, the first determining module is further used for:

[0067] If the second least squares parameter estimation index is not less than the second threshold, carrier phase observation values ​​satisfying the second elimination condition in the first GNSS measurement data and the second GNSS measurement data are eliminated;

[0068] If the total number of remaining carrier phase observation values ​​is not less than the second total number threshold, the iterative calculation of the second position is re-executed based on the remaining first GNSS measurement data and the second GNSS measurement data.

[0069] An embodiment of the present application also provides an electronic device, comprising: a processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor and the memory communicate via the bus, and when the machine-readable instructions are executed by the processor, the steps of the re-convergence method as described above are performed.

[0070] An embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned re-convergence method are executed.

[0071] The embodiments of the present application provide a reconvergence method and device for precise point positioning, the reconvergence method comprising: after signal recovery, obtaining first GNSS measurement data of the current epoch and second GNSS measurement data of the previous valid epoch, and determining the differential age between the two; if the differential age is not greater than the age threshold, performing inter-epoch differential positioning solution according to the first GNSS measurement data and the second GNSS measurement data to determine the estimated position of the receiver; wherein the differential positioning solution comprises inter-epoch pseudorange differential positioning solution and inter-epoch carrier phase differential positioning solution; determining the initial state parameters required for precise point positioning update according to the first GNSS measurement data, the second GNSS measurement data and the estimated position; the initial state parameters comprise receiver position correction numbers, which are determined according to the estimated position; performing filtering solution processing according to the initial state parameters and the precise point positioning observation equation to determine the target position of the receiver.

[0072] In this way, by judging the differential age of the current epoch and the previous valid epoch, ensuring that the differential data within a certain age threshold range is used for reconvergence, the time correlation of the data can be ensured, thereby enhancing the accuracy of positioning. And by using pseudo-range differential and carrier phase differential positioning solutions, the continuity between multiple epochs can be effectively utilized to improve the accuracy of initial position estimation, so that the receiver can lock onto a more accurate position more quickly, thereby greatly shortening the reconvergence time. In addition, the estimated position obtained based on the differential solution is used to determine the initial state parameters required for precise point positioning (PPP), especially the receiver position correction number. This process reduces the complexity of re-estimation from scratch, making the starting point of the precise point positioning process closer to the actual position, thereby shortening the convergence time of PPP.

[0073] Therefore, this method significantly shortens the reconvergence time after GNSS signal recovery by combining differential age judgment with inter-epoch differential positioning, while ensuring positioning accuracy.

[0074] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0076] Figure 1 A flowchart of a re-convergence method for precise point positioning provided in an embodiment of the present application;

[0077] Figure 2 A flowchart of a method for determining an estimated position of a receiver provided in an embodiment of the present application;

[0078] Figure 3 A schematic diagram of the structure of a precise single-point positioning re-convergence device provided in an embodiment of the present application;

[0079] Figure 4 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0080] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application usually described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, each other embodiment obtained by those skilled in the art without making creative work belongs to the scope of protection of the present application.

[0081] Precise Point Positioning (PPP) technology is a technology that achieves high-precision positioning through a single receiver. It has the advantages of portability, flexibility, low cost and wide operating range. It can provide high-precision positioning services for the majority of GNSS (Global Navigation Satellite System) users and has been widely used in many fields such as geodetic surveying.

[0082] Although the current satellite navigation resources have been greatly improved with the construction and development of the global satellite navigation system, PPP still has the problem of long convergence time. It usually takes about 20 minutes to achieve centimeter-level positioning results, which seriously restricts the application of PPP in high-precision positioning. Due to reasons such as satellite signal blocking, the signal will be lost, the carrier phase observation value will jump or be interrupted, and re-convergence is required. In complex scenarios, satellite signals are prone to frequent blocking problems, and the performance of PPP will be greatly reduced.

[0083] Based on this, an embodiment of the present application provides a re-convergence method and device for precise single-point positioning. The present application determines a relatively accurate receiver position as the PPP initial position parameter through inter-epoch differential positioning solution processing, thereby improving the position accuracy during PPP re-initialization, thereby achieving rapid re-convergence of PPP.

[0084] See also Figure 1 , Figure 1 This is a flow chart of a reconvergence method for precise point positioning provided in an embodiment of the present application. Figure 1 As shown in , the reconvergence method provided in the embodiment of the present application includes:

[0085] S101. When the signal is restored, obtain the first GNSS measurement data of the current epoch and the second GNSS measurement data of the previous valid epoch, and determine the differential age between the two.

[0086] S102: If the differential age is not greater than the age threshold, perform inter-epoch differential positioning solution according to the first GNSS measurement data and the second GNSS measurement data to determine an estimated position of the receiver.

[0087] S103: Determine initial state parameters required for precise point positioning update according to the first GNSS measurement data, the second GNSS measurement data, and the estimated position.

[0088] S104: Perform filtering and solving processing according to the initial state parameters and the precise point positioning observation equation to determine the target position of the receiver.

[0089] It should be noted that the length of PPP convergence time mainly depends on the length of the estimation time of the parameters to be determined, which may include three-dimensional position, receiver clock error, tropospheric wet delay and carrier phase ambiguity. When the satellite signal is lost, the carrier phase ambiguity parameters need to be reinitialized. When there are many satellite signals that lose lock at the same time, the speed of convergence of the carrier phase ambiguity parameters mainly depends on the accuracy of other parameters. The receiver clock error parameters are generally estimated by single-point positioning, and the tropospheric wet delay is estimated by the model and filtering. There is a certain degree of difficulty in improving the accuracy of the two. Therefore, the accuracy of the three-dimensional position parameters is the key to affecting the re-convergence speed. However, traditional methods usually use pseudo-range single-point positioning to obtain the initial position parameters of PPP. Based on the relatively low-precision initial position parameters, a longer convergence time is required.

[0090] With respect to step S101, in this step, when the receiver signal is restored, the first GNSS measurement data of the current epoch (time point) is first obtained, and the second GNSS measurement data of the previous valid epoch is simultaneously obtained, and the differential age between the two epochs is calculated based on the observation time of the two epochs.

[0091] Here, the first GNSS measurement data includes observation data and navigation messages of the current epoch, so that the approximate three-dimensional position of the receiver and the receiver clock error of the current epoch can be calculated based on the first GNSS measurement data through the pseudo-range single-point positioning method.

[0092] The second GNSS measurement data includes observation data of the previous valid epoch (before signal interruption), navigation messages, and positioning results of the receiver (historical position of the receiver).

[0093] The differential age refers to the time difference between two epochs.

[0094] When calculating the differential age, the observation time of two epochs (the observation data includes the observation time) can be subtracted to obtain the differential age between the epochs.

[0095] For example, suppose the current epoch is 10 seconds, the previous valid epoch is 8 seconds, and the differential age between the two is 2 seconds.

[0096] With respect to step S102, in this step, if the differential age does not exceed the set threshold, the GNSS measurement data of the two epochs are used to perform differential positioning solution to deduce the estimated position of the receiver.

[0097] Here, the differential positioning solution includes the inter-epoch pseudorange differential positioning solution and the inter-epoch carrier phase differential positioning solution.

[0098] Pseudorange differential positioning: The position change is calculated using the pseudorange data of two epochs, and the position of the receiver is calculated based on the position correction. Carrier phase differential positioning: The carrier phase data of two epochs is used for higher-precision differential calculation to obtain the position change, and the position of the receiver is calculated based on the position correction.

[0099] The age threshold can be preset based on experience. It should be noted that, since the residual error in the double difference model will increase synchronously when the difference age increases, it is necessary to set the age threshold.

[0100] For example, the age threshold is generally set within 30 seconds, for example, 30 seconds, 25 seconds.

[0101] For examples, see Figure 2 , Figure 2 A flowchart of a method for determining an estimated position of a receiver provided in an embodiment of the present application. Figure 2 As shown, performing inter-epoch differential positioning solution based on the first GNSS measurement data and the second GNSS measurement data to determine the estimated position of the receiver includes:

[0102] S1021. Perform inter-epoch pseudorange differential positioning solution according to the first GNSS measurement data and the second GNSS measurement data to determine whether there is a first position of the receiver that meets the solution requirements.

[0103] S1022: If the first position exists, perform inter-epoch carrier phase differential positioning solution according to the first GNSS measurement data and the second GNSS measurement data to determine whether there is a second position of the receiver that meets the solution requirements.

[0104] S1023: If the first position exists but the second position does not exist, determine the first position as the estimated position.

[0105] S1024: If both the first position and the second position exist, determine the second position as the estimated position.

[0106] With respect to step S1021, in this step, pseudo-range data of the first GNSS measurement data and the second GNSS measurement data are used to perform inter-epoch pseudo-range differential positioning solution to determine whether a first position of the receiver that meets the solution requirements can be obtained. If the first position is selected, step S1022 is executed.

[0107] For step S1022, in this step, if it is determined that there is a first position that meets the requirements, a higher-precision carrier phase differential positioning solution between epochs is further performed based on the carrier phase data to determine whether the second position of the receiver can be determined. If the second position is screened out, step S1024 is executed, and if the second position is not screened out, step S1023 is executed.

[0108] It should be noted that the result of carrier phase differential positioning is more accurate than the result of pseudorange differential positioning, and can further refine the position of the receiver. In addition, the position accuracy of the first position and the second position is higher than the position accuracy of the approximate position.

[0109] With respect to step S1023, if the pseudorange differential positioning solution obtains the first position but the carrier phase differential positioning solution cannot obtain the second position, the first position is directly used as the final estimated position.

[0110] With respect to step S1024, if both the pseudorange differential positioning and the carrier phase differential positioning successfully obtain a position, the second position with higher accuracy is used as the final estimated position.

[0111] With respect to step S1021, in one implementation manner provided in the present application, performing inter-epoch pseudorange differential positioning solution based on the first GNSS measurement data and the second GNSS measurement data to determine whether there is a first position of the receiver that meets the solution requirements includes:

[0112] S10211. For each of the target satellites, determine a first pseudorange undifference observation equation for a current epoch based on the first GNSS measurement data, and determine a second pseudorange undifference observation equation for a previous valid epoch based on the second GNSS measurement data.

[0113] S10212. According to the first pseudorange undifference observation equation and the second pseudorange undifference observation equation, for each of the target satellites, differential processing is performed according to a preset differential rule based on the pseudorange undifference observation equation between two epochs corresponding to the same target satellite to determine a pseudorange single-difference observation equation.

[0114] S10213. Use one of the target satellites as a reference satellite, perform re-difference processing on the pseudo-range single-difference observation equation corresponding to the reference satellite and the pseudo-range single-difference observation equations corresponding to the remaining target satellites one by one according to a preset difference rule, and determine a pseudo-range double-difference model.

[0115] S10214. Construct a first target matrix according to all pseudorange double-difference models.

[0116] S10215, performing least squares parameter estimation based on the first target matrix to determine the first epoch position difference and the first least squares parameter estimation index.

[0117] S10216. If the first least squares parameter estimation index is less than the first threshold, the first epoch position difference is the first epoch target position difference.

[0118] S10217: Use the first epoch target position difference to update the historical position of the receiver determined according to the second GNSS measurement data, and determine the first position of the receiver in the current epoch.

[0119] S10218. If the first least squares parameter estimation index is not less than the first threshold, the pseudorange observation values ​​that meet the first elimination condition in the first GNSS measurement data and the second GNSS measurement data are eliminated. If the total number of remaining pseudorange observation values ​​is not less than the first total number threshold, return to step S10215 for iterative calculation based on the remaining first GNSS measurement data and the second GNSS measurement data.

[0120] For step S10211, for each of the target satellites, the pseudo-range undifference observation equation of the current epoch is constructed based on the first GNSS measurement data of the current epoch; and the pseudo-range undifference observation equation of the previous valid epoch is constructed based on the second GNSS measurement data of the previous valid epoch.

[0121] The pseudorange non-difference observation equation is an equation constructed based on pseudorange observation values ​​without any differential processing.

[0122] For example, when there are N target satellites, there are N first pseudo-range undifference observation equations and N second pseudo-range undifference observation equations.

[0123] For step S10212, according to the first pseudorange undifference observation equation and the second pseudorange undifference observation equation, a differential calculation is performed on each of the target satellites based on the pseudorange undifference observation equation between two epochs corresponding to the same target satellite according to a preset differential rule to determine the pseudorange single-difference observation equation between the two epochs of the target satellite.

[0124] For example, when there are N target satellites, the first pseudorange non-difference observation equation corresponding to the first satellite and the second pseudorange non-difference observation equation corresponding to the first satellite are differentially processed to determine the pseudorange single-difference observation equation corresponding to the first satellite; the first pseudorange non-difference observation equation corresponding to the second satellite and the second pseudorange non-difference observation equation corresponding to the second satellite are differentially processed to determine the pseudorange single-difference observation equation corresponding to the second satellite; and so on, the first pseudorange non-difference observation equation corresponding to the Nth satellite and the second pseudorange non-difference observation equation corresponding to the Nth satellite are differentially processed to determine the pseudorange single-difference observation equation corresponding to the Nth satellite.

[0125] Regarding step S10213, in this step, based on the single difference, difference processing is performed again, and a pseudorange double difference model is constructed according to the preset difference rules.

[0126] For example, when there are N target satellites, the first satellite can be used as a reference satellite (generally, a satellite with better observation quality is selected as the reference satellite). Then, the pseudo-range single-difference observation equation corresponding to the second satellite is differentially processed with the pseudo-range single-difference observation equation corresponding to the first satellite to determine the first pseudo-range double-difference model; the pseudo-range single-difference observation equation corresponding to the third satellite is differentially processed with the pseudo-range single-difference observation equation corresponding to the first satellite to determine the second pseudo-range double-difference model; and so on, the pseudo-range single-difference observation equation corresponding to the Nth satellite is differentially processed with the pseudo-range single-difference observation equation corresponding to the 1st satellite to determine the N-1th pseudo-range double-difference model.

[0127] With respect to step S10214, in this step, a first target matrix is ​​constructed using all pseudorange double-difference models.

[0128] For step S10215, in this step, based on the first target matrix, parameter estimation is performed by the least squares method to determine the first epoch position difference, and the posterior residual of each pseudorange observation value is calculated based on the first epoch position difference. The posterior residual results of each pseudorange observation value are normalized to obtain the first least squares parameter estimation index.

[0129] For step S10216, in this step, it is determined whether the threshold condition is met. If the first least squares parameter estimation index is less than the corresponding threshold (first threshold), the inter-epoch position difference (first inter-epoch position difference) solved by the pseudorange double difference is output, that is, the first inter-epoch position difference is used as the first inter-epoch target position difference.

[0130] If the first least squares parameter estimation index is not less than the first threshold, execute step S10218.

[0131] For step S10217, for example, in this step, the sum of the target position difference between the first epochs and the historical position is determined as the first position of the receiver in the current epoch.

[0132] For step S10218, if the first least squares parameter estimation index is not less than the first threshold, the abnormal data that causes the largest residual in the pseudorange observation value and affects the solution quality and meets the first elimination condition is eliminated (the first elimination condition is the pseudorange observation value corresponding to the maximum ratio of the sum of squares of the post-validation residual and the pre-validation deviation in the pseudorange observation value). If the total number of remaining pseudorange observation values ​​is not less than the first total number threshold, return to step S10215, perform iterative calculation based on the remaining first GNSS measurement data and the second GNSS measurement data, re-perform least squares estimation, and obtain the updated first epoch position difference and the first least squares parameter estimation index.

[0133] It can be understood that the updated first least squares parameter estimation index is compared with the first threshold. If it is still not less than the first threshold, step S10215 is repeated until the updated first least squares parameter estimation index is less than the first threshold, thereby outputting the corresponding first epoch position difference.

[0134] For steps S10216 and S10218, the first threshold and the first total threshold are pre-set.

[0135] For example, with respect to steps S10211-S10218, the process of determining the first position is described by way of example through the following content:

[0136] First, assuming that the last valid epoch is j and the current epoch is k, the pseudorange undifference observation equation for the last epoch j is:

[0137]

[0138] In the formula, the superscript S represents the satellite, and the subscript j represents the epoch number. represents the pseudo-range observation value of satellite S at time j, represents the distance between the satellite and the earth, c is the speed of light, dt j is the receiver clock error, dt S is the satellite clock error, is the tropospheric delay error, is the ionospheric delay error, is the residual error of pseudorange observation. The calculation formula of satellite-to-earth distance is:

[0139]

[0140] In the formula, (X S ,Y S ,Z S) is the satellite position, and its value can be obtained from the satellite ephemeris. j ,Y j ,Z j ) is the receiver position at epoch j, let it be a vector X, which can be expressed as:

[0141] X=X0+x,

[0142] Where X0 is the approximate receiver position (obtained based on the approximate position of the receiver), and x is the receiver position correction. Linearizing the satellite-to-earth distance yields:

[0143]

[0144] In the formula, Indicates the distance between the satellite and the approximate position of the receiver, Represents the three-dimensional direction cosines corresponding to the satellite-to-earth distance.

[0145] Then the original pseudo-range undifference observation equation of epoch j can be rewritten as:

[0146]

[0147] Similarly, the pseudo-range undifference observation equation of the current epoch k is:

[0148]

[0149] Then, the pseudorange single-difference observation equation of the current epoch and the previous epoch is established.

[0150] When satellite A is observed in both epochs, the pseudo-range non-difference observation equations of the two are single-differenced between the epochs to obtain:

[0151]

[0152] In the formula, Δ() represents the single difference operator. In a short period of time, the changes in satellite clock errors, troposphere and ionosphere are extremely small and can be ignored. Therefore, the above errors can be eliminated by making a difference.

[0153] Similarly, when satellite B is observed at both epochs, we can obtain:

[0154]

[0155] Finally, by continuing to make inter-satellite single differences on the two equations, we can get the double difference model:

[0156]

[0157] In the formula, represents the double difference operator, which further eliminates the receiver clock error through the inter-satellite single difference, and the final parameter to be estimated is the position difference dx between epochs.

[0158] Through the double difference model, the various matrices required for parameter estimation are constructed, and the least squares parameter estimation is performed to obtain the position difference dx between epochs. The posterior residuals of each pseudorange observation are calculated based on the position difference dx between epochs and the pseudorange observations. The posterior residual results of each pseudorange observation are normalized to obtain the least squares parameter estimation index. If the estimation index is less than the set threshold, the iteration is completed, and the position difference dx between epochs solved by the pseudorange double difference is output. If it is greater than the threshold, the pseudorange observation corresponding to the maximum ratio of the sum of squares of the posterior residuals to the pre-test deviations in the pseudorange observations is eliminated (the reason for elimination is that the error of the pseudorange observation is large), and the least squares estimation is performed again. The above steps are repeated until it is less than the threshold, and a higher precision result is output. If the total number of pseudorange observations is less than 3 and the estimation index is still not less than the set threshold, the least squares will have no output (the first position is empty). If there is an output, the receiver position of this epoch k can be updated by the following formula:

[0159] X k =X j +dx,

[0160] Where, the position X of the previous epoch j is j It is obtained based on the positioning result in the historical position (determined according to the second GNSS measurement data).

[0161] With respect to step S1022, in one implementation manner provided in the present application, performing inter-epoch carrier phase differential positioning solution according to the first GNSS measurement data and the second GNSS measurement data to determine whether there is a second position of the receiver that meets the solution requirements includes:

[0162] S10221. For each of the target satellites, determine a first carrier phase non-difference observation equation for a current epoch based on the first GNSS measurement data, and determine a second carrier phase non-difference observation equation for a previous valid epoch based on the second GNSS measurement data.

[0163] S10222. According to the first carrier phase undifference observation equation and the second carrier phase undifference observation equation, for each of the target satellites, differential processing is performed according to a preset differential rule based on the carrier phase undifference observation equation between two epochs corresponding to the same target satellite to determine a carrier phase single-difference observation equation.

[0164] S10223. Take one of the target satellites as a reference satellite, perform difference processing again on the carrier phase single-difference observation equation corresponding to the reference satellite and the carrier phase single-difference observation equations corresponding to the remaining target satellites one by one according to preset difference rules, and determine a carrier phase double-difference model.

[0165] S10224. Construct a second target matrix according to all carrier phase double-difference models.

[0166] S10225. Perform least squares parameter estimation based on the second target matrix to determine the second epoch position difference and the second least squares parameter estimation index.

[0167] S10226. If the second least squares parameter estimation index is less than the second threshold, the second epoch position difference is the second epoch target position difference.

[0168] S10227. Use the target position difference between the second epochs to update the historical position of the receiver determined according to the second GNSS measurement data, and determine the second position of the receiver in the current epoch.

[0169] S10228. If the second least squares parameter estimation index is not less than the second threshold, the carrier phase observation values ​​that meet the second elimination condition in the first GNSS measurement data and the second GNSS measurement data are eliminated. If the total number of remaining carrier phase observation values ​​is not less than the second total number threshold, return to step S10225 for iterative calculation based on the remaining first GNSS measurement data and the second GNSS measurement data.

[0170] For step S10221, for each of the target satellites, the carrier phase non-difference observation equation of the current epoch is constructed based on the first GNSS measurement data of the current epoch; and the carrier phase non-difference observation equation of the previous valid epoch is constructed based on the second GNSS measurement data of the previous valid epoch.

[0171] The carrier phase non-difference observation equation is an equation constructed based on the carrier phase observation value without any differential processing.

[0172] For example, when there are N target satellites, there are N first carrier phase non-difference observation equations and N second carrier phase non-difference observation equations.

[0173] For step S10222, according to the first carrier phase non-difference observation equation and the second carrier phase non-difference observation equation, a differential calculation is performed on each of the target satellites according to a preset differential rule based on the carrier phase non-difference observation equation between two epochs corresponding to the same target satellite to determine the carrier phase single-difference observation equation between the two epochs of the target satellite.

[0174] For example, when there are N target satellites, the first carrier phase non-difference observation equation corresponding to the first satellite and the second carrier phase non-difference observation equation corresponding to the first satellite are differentially processed to determine the carrier phase single-difference observation equation corresponding to the first satellite; the first carrier phase non-difference observation equation corresponding to the second satellite and the second carrier phase non-difference observation equation corresponding to the second satellite are differentially processed to determine the carrier phase single-difference observation equation corresponding to the second satellite; and so on, the first carrier phase non-difference observation equation corresponding to the Nth satellite and the second carrier phase non-difference observation equation corresponding to the Nth satellite are differentially processed to determine the carrier phase single-difference observation equation corresponding to the Nth satellite.

[0175] Regarding step S10223, in this step, based on the single difference, differential processing is performed again, and a carrier phase double difference model is constructed according to a preset differential rule.

[0176] For example, when there are N target satellites, the first satellite can be used as a reference satellite (generally, a satellite with better observation quality is selected as the reference satellite). Then, the carrier phase single-difference observation equation corresponding to the second satellite is differentially processed with the carrier phase single-difference observation equation corresponding to the first satellite to determine the first carrier phase double-difference model; the carrier phase single-difference observation equation corresponding to the third satellite is differentially processed with the carrier phase single-difference observation equation corresponding to the first satellite to determine the second carrier phase double-difference model; and so on, the carrier phase single-difference observation equation corresponding to the Nth satellite is differentially processed with the carrier phase single-difference observation equation corresponding to the 1st satellite to determine the N-1th carrier phase double-difference model.

[0177] With respect to step S10224, in this step, a second target matrix is ​​constructed using all carrier phase double-difference models.

[0178] For step S10225, in this step, based on the second target matrix, parameter estimation is performed by the least squares method to determine the position difference between the second epochs, and the posterior residuals of each carrier phase observation value are calculated based on the position difference between the second epochs. The posterior residual results of each carrier phase observation value are normalized and the second least squares parameter estimation index is obtained.

[0179] For step S10226, in this step, it is determined whether the threshold condition is met. If the second least squares parameter estimation index is less than the corresponding threshold (second threshold), the inter-epoch position difference (second inter-epoch position difference) of the carrier phase double difference solution is output, that is, the second inter-epoch position difference is used as the second inter-epoch target position difference.

[0180] If the second least squares parameter estimation index is not less than the second threshold, execute step S10228.

[0181] For step S10227, illustratively, in this step, the sum of the target position difference between the second epochs and the historical position is determined as the second position of the receiver in the current epoch.

[0182] For step S10228, if the second least squares parameter estimation index is not less than the second threshold, then the abnormal data that meets the second elimination condition in the carrier phase observation value that causes the residual to be too large and affects the solution quality is eliminated (the second elimination condition is the carrier phase observation value corresponding to the post-test residual in the carrier phase observation value that is greater than the residual threshold. In this case, it can be regarded as a cycle slip that has occurred, resulting in the ambiguity parameter after differentiation being not zero, making the post-test residual too large). If the total number of remaining carrier phase observation values ​​is not less than the second total threshold, the least squares estimation is performed again to obtain the updated second epoch position difference and the second least squares parameter estimation index.

[0183] It can be understood that the updated second least squares parameter estimation index is compared with the second threshold. If it is still not less than the second threshold, step S10225 is repeated until the updated second least squares parameter estimation index is less than the second threshold, thereby outputting the corresponding second epoch position difference.

[0184] For steps S10226 and S10228, the second threshold and the second total threshold are pre-set.

[0185] For example, with respect to steps S10221-S10228, the process of determining the second position is described by way of example through the following content:

[0186] To perform carrier phase differential positioning between epochs, first, the non-difference observation equation of the carrier phase at time j is:

[0187]

[0188] Where λ is the carrier phase wavelength, is the carrier phase observation value of satellite S at time j, is the undifferenced carrier phase ambiguity, is the residual error of the undifferenced carrier phase observation.

[0189] Similarly, the carrier phase non-difference observation equation at time k is:

[0190]

[0191] Then, the single-difference observation equation of the carrier phase of the current epoch and the previous epoch is established.

[0192] When satellite A is observed in both epochs, the carrier phase non-difference observation equations of the two are single-differenced between epochs to obtain:

[0193]

[0194] Similar to pseudorange observations, satellite clock errors, tropospheric and ionospheric errors are eliminated by inter-epoch difference. In addition, when the carrier phase observation does not have a cycle slip, its ambiguity parameter should be constant, so the parameter can also be eliminated by inter-epoch difference.

[0195] Similarly, when satellite B is observed at both epochs, we can obtain:

[0196]

[0197] Finally, by continuing to make inter-satellite single differences on the two equations, we can get the double difference model:

[0198]

[0199] The receiver clock error is further eliminated through inter-satellite single difference, and the final parameter to be estimated is the position difference dx between epochs.

[0200] Similar to the pseudorange positioning differential decomposition, matrix construction and parameter estimation are performed, and the inter-epoch position difference dx is obtained by iterative solution. The posterior residual of each carrier phase observation is calculated based on the inter-epoch position difference dx and the carrier phase observation value. The posterior residual results of each carrier phase observation value are normalized to obtain the least squares parameter estimation index. If the estimation index is less than the set threshold, the iteration is completed, and the inter-epoch position difference dx solved by the carrier phase double difference is output. If it is greater than the threshold, it can be regarded as a cycle slip, resulting in the difference The ambiguity parameter is not zero, making the posterior residual larger, then the carrier phase observation value corresponding to the posterior residual greater than the residual threshold is eliminated, and the least squares estimation is performed again, and the above steps are repeated until it is less than the threshold, and the high-precision inter-epoch carrier phase differential positioning result dx is output. If the total number of carrier phase observations is less than 3 when the cycle is repeated, and the estimation index is still not less than the set threshold, the least squares will have no output (the second position is empty). If there is an output, the receiver position of this epoch k can be updated by the following formula:

[0201] X k =X j +dx.

[0202] It should be noted that this scheme must be carried out in the order of first updating the first position based on the pseudorange observation value and then updating the second position based on the carrier phase observation value. This is because although the ranging accuracy of the pseudorange observation value is low, it is not affected by cycle slips and is easy to obtain, so it can be used as a pre-update. Although the ranging accuracy of the carrier phase observation value is high, it is affected by cycle slips. When the number of carrier phase observation values ​​with cycle slips is large, it may result in less carrier phase observation value data participating in the solution. Therefore, it is set as a post-update.

[0203] With respect to step S103, in this step, initial state parameters required for precise point positioning (PPP) are determined based on the GNSS measurement data of the first and second epochs and the estimated position.

[0204] The initial state parameters include a receiver position correction number, which is determined based on the estimated position and the approximate position of the receiver at the current epoch calculated based on the first GNSS measurement data. The correction number is calculated based on the estimated position and the approximate position and is used as an input for subsequent precise point positioning.

[0205] The initial state parameters also include the receiver clock difference dt of each GNSS system, the tropospheric wet delay parameter ZWD, and the carrier phase ambiguity N of each satellite.

[0206] The receiver clock error is calculated from the first GNSS measurement data. The initial value of ZWD is calculated by the model. White noise modeling is subsequently used. The initial value of the carrier phase deviation N is calculated from the difference between the pseudorange and the corresponding distance of the carrier phase observation value and is treated as a constant. The carrier phase observation value should be reinitialized when a cycle slip occurs.

[0207] After the correction in step S102, the initial coordinates with better accuracy are solved, based on which a better carrier phase ambiguity can be calculated, which is conducive to the rapid convergence of the carrier phase deviation parameters, thereby finally achieving the rapid convergence of PPP. The traditional method generally directly uses the approximate coordinates solved by single point positioning as the initial coordinates for PPP solution, which has low accuracy and therefore requires a long convergence time.

[0208] Regarding step S104, in this step, filtering and solving are performed according to the initial state parameters and the observation equation of the precise point positioning to obtain the final target position of the receiver. PPP usually uses Kalman filtering for filtering and solving.

[0209] For example, the step includes: performing PPP measurement update and establishing PPP observation equations. Here, the ionosphere-free combination is taken as an example:

[0210]

[0211] In the formula, parameter S represents the satellite, IF represents the ionosphere-free combination, and They represent the pseudorange and carrier phase observation values ​​of the ionosphere-free combination, u S represents the direction cosine, x represents the receiver's three-dimensional position correction, c represents the speed of light, dt is the receiver's clock error, Mw S represents the tropospheric projection function, ZWD represents the tropospheric wet delay parameter, represents the carrier phase deviation, and Respectively represent the residual errors of pseudorange and carrier phase observations. The random model of the observations is determined by the altitude angle model, and its formula is:

[0212] σ 2 =a 2 +b 2 / sin 2 E,

[0213] Where E represents the satellite elevation angle, a and b are constants. For pseudorange and carrier phase observations, different constants are used due to the different ranging accuracy of their observations, and their corresponding ratios can be set to 100:1.

[0214] The observation equation and the observation noise matrix are constructed according to the observation data (including the initial state parameters) and their random models. Kalman filter solution is performed, the PPP positioning information is updated, the required state information is saved for the next epoch solution, and the final solution result of the current epoch (the target position of the receiver) is output.

[0215] By determining the differential age of the current epoch and the previous valid epoch, and ensuring that differential data within a certain age threshold is used for reconvergence, the time correlation of the data can be ensured, thereby enhancing the accuracy of positioning. In addition, by using pseudorange differential and carrier phase differential positioning solutions, the continuity between multiple epochs can be effectively utilized to improve the accuracy of initial position estimation, allowing the receiver to lock onto a more accurate position more quickly, thereby greatly shortening the reconvergence time. In addition, the estimated position obtained based on differential decomposition is used to determine the initial state parameters required for precise point positioning (PPP), especially the receiver position correction number. This process reduces the complexity of re-estimation from scratch, making the starting point of the precise point positioning process closer to the actual position, thereby shortening the convergence time of PPP.

[0216] Based on the same inventive concept, a re-convergence device corresponding to the re-convergence method is also provided in the embodiment of the present application. Since the principle of solving the problem by the device in the embodiment of the present application is similar to the above-mentioned re-convergence method in the embodiment of the present application, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be repeated.

[0217] See also Figure 3 , Figure 3 This is a schematic diagram of the structure of a precise single-point positioning re-convergence device provided in an embodiment of the present application. Figure 3 As shown in , the reconvergence device 300 includes:

[0218] The acquisition module 310 is used to acquire the first GNSS measurement data of the current epoch and the second GNSS measurement data of the previous valid epoch after the signal is restored, and determine the differential age between the two;

[0219] A first determination module 320 is configured to perform an inter-epoch differential positioning solution based on the first GNSS measurement data and the second GNSS measurement data to determine an estimated position of the receiver if the differential age is not greater than the age threshold; wherein the differential positioning solution includes an inter-epoch pseudorange differential positioning solution and an inter-epoch carrier phase differential positioning solution;

[0220] A second determination module 330 is used to determine initial state parameters required for precise point positioning update according to the first GNSS measurement data, the second GNSS measurement data and the estimated position; the initial state parameters include a receiver position correction number, and the receiver position correction number is determined according to the estimated position;

[0221] The first processing module 340 is used to perform filtering and solving processing according to the initial state parameters and the precise point positioning observation equation to determine the target position of the receiver.

[0222] Optionally, when the first determination module 320 is used to perform inter-epoch differential positioning solution according to the first GNSS measurement data and the second GNSS measurement data to determine the estimated position of the receiver, the first determination module 320 is used to:

[0223] Perform inter-epoch pseudorange differential positioning solution based on the first GNSS measurement data and the second GNSS measurement data to determine whether there is a first position of the receiver that meets the solution requirements;

[0224] If the first position exists, performing inter-epoch carrier phase differential positioning solution according to the first GNSS measurement data and the second GNSS measurement data to determine whether there is a second position of the receiver that meets the solution requirements;

[0225] If the first position exists but the second position does not exist, determining the first position as the estimated position;

[0226] If both the first position and the second position exist, the second position is determined as the estimated position.

[0227] Optionally, when the first determination module 320 is used to perform inter-epoch pseudorange differential positioning solution according to the first GNSS measurement data and the second GNSS measurement data to determine whether there is a first position of the receiver that meets the solution requirements, the first determination module 320 is used to:

[0228] For each of the target satellites, a first pseudorange undifferenced observation equation of a current epoch is determined according to the first GNSS measurement data, and a second pseudorange undifferenced observation equation of a previous valid epoch is determined according to the second GNSS measurement data;

[0229] According to the first pseudorange non-difference observation equation and the second pseudorange non-difference observation equation, for each of the target satellites, a pseudorange single-difference observation equation is determined by performing differential processing according to a preset differential rule based on the pseudorange non-difference observation equation between two epochs corresponding to the same target satellite;

[0230] One of the target satellites is used as a reference satellite, and the pseudo-range single-difference observation equation corresponding to the reference satellite and the pseudo-range single-difference observation equations corresponding to the remaining target satellites are subjected to a second difference process according to a preset difference rule to determine a pseudo-range double-difference model;

[0231] Constructing a first target matrix according to all pseudorange double-difference models;

[0232] Performing least squares parameter estimation based on the first target matrix, determining the first inter-epoch position difference and the first least squares parameter estimation index;

[0233] If the first least squares parameter estimation index is less than the first threshold, the first epoch position difference is the first epoch target position difference;

[0234] The historical position of the receiver determined according to the second GNSS measurement data is updated using the first inter-epoch target position difference to determine a first position of the receiver at a current epoch.

[0235] Optionally, the first determining module 320 is further configured to:

[0236] If the first least squares parameter estimation index is not less than a first threshold, the pseudorange observation values ​​satisfying the first elimination condition in the first GNSS measurement data and the second GNSS measurement data are eliminated;

[0237] If the total number of remaining pseudorange observation values ​​is not less than the first total number threshold, the iterative calculation of the first position is re-executed based on the remaining first GNSS measurement data and the second GNSS measurement data.

[0238] Optionally, when the first determination module 320 is used to perform inter-epoch carrier phase differential positioning solution according to the first GNSS measurement data and the second GNSS measurement data to determine whether there is a second position of the receiver that meets the solution requirements, the first determination module 320 is used to:

[0239] For each of the target satellites, a first carrier phase undifference observation equation of a current epoch is determined according to the first GNSS measurement data, and a second carrier phase undifference observation equation of a previous valid epoch is determined according to the second GNSS measurement data;

[0240] According to the first carrier phase non-difference observation equation and the second carrier phase non-difference observation equation, for each of the target satellites, a carrier phase single-difference observation equation is determined by performing differential processing according to a preset differential rule based on the carrier phase non-difference observation equation between two epochs corresponding to the same target satellite;

[0241] One of the target satellites is used as a reference satellite, and the carrier phase single-difference observation equation corresponding to the reference satellite and the carrier phase single-difference observation equations corresponding to the remaining target satellites are subjected to difference processing one by one according to a preset difference rule to determine a carrier phase double-difference model;

[0242] Constructing a second target matrix according to all carrier phase double difference models;

[0243] Performing least squares parameter estimation based on the second target matrix to determine the second epoch position difference and the second least squares parameter estimation index;

[0244] If the second least squares parameter estimation index is less than the second threshold, the second epoch position difference is the second epoch target position difference;

[0245] The historical position of the receiver determined according to the second GNSS measurement data is updated using the target position difference between the second epochs to determine the second position of the receiver in the current epoch.

[0246] Optionally, the first determining module 320 is further configured to:

[0247] If the second least squares parameter estimation index is not less than the second threshold, carrier phase observation values ​​satisfying the second elimination condition in the first GNSS measurement data and the second GNSS measurement data are eliminated;

[0248] If the total number of remaining carrier phase observation values ​​is not less than the second total number threshold, the iterative calculation of the second position is re-executed based on the remaining first GNSS measurement data and the second GNSS measurement data.

[0249] See also Figure 4 , Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Figure 4 As shown in , the electronic device 400 includes a processor 410 , a memory 420 and a bus 430 .

[0250] The memory 420 stores machine-readable instructions executable by the processor 410. When the electronic device 400 is running, the processor 410 communicates with the memory 420 via the bus 430. When the machine-readable instructions are executed by the processor 410, the above-mentioned Figure 1 and Figure 2The specific implementation of the steps in the method embodiment shown can be found in the method embodiment, and will not be repeated here.

[0251] The present application also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the computer program can execute the above-mentioned Figure 1 and Figure 2 The specific implementation of the steps in the method embodiment shown can be found in the method embodiment, and will not be repeated here.

[0252] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0253] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0254] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0255] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0256] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present application can essentially be embodied in the form of a software product, or in other words, the part that contributes to the prior art or the part of the technical solution. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0257] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The protection scope of the present application is not limited thereto. Although the present application is described in detail with reference to the above-mentioned embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-mentioned embodiments within the technical scope disclosed in the present application, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A reconvergence method for precise point positioning, characterized in that: The reconvergence method comprises: When the signal is restored, the first GNSS measurement data of the current epoch and the second GNSS measurement data of the previous valid epoch are obtained, and the differential age between the two is determined; If the differential age is not greater than the age threshold, performing inter-epoch differential positioning solution according to the first GNSS measurement data and the second GNSS measurement data to determine the estimated position of the receiver; wherein the differential positioning solution includes inter-epoch pseudorange differential positioning solution and inter-epoch carrier phase differential positioning solution; Determining initial state parameters required for precise point positioning update based on the first GNSS measurement data, the second GNSS measurement data, and the estimated position; the initial state parameters include a receiver position correction number, and the receiver position correction number is determined based on the estimated position; According to the initial state parameters and the precise point positioning observation equation, filtering and solving are performed to determine the target position of the receiver.

2. The reconvergence method according to claim 1, characterized in that: The method of performing inter-epoch differential positioning solution based on the first GNSS measurement data and the second GNSS measurement data to determine the estimated position of the receiver includes: Perform inter-epoch pseudorange differential positioning solution based on the first GNSS measurement data and the second GNSS measurement data to determine whether there is a first position of the receiver that meets the solution requirements; If the first position exists, performing inter-epoch carrier phase differential positioning solution according to the first GNSS measurement data and the second GNSS measurement data to determine whether there is a second position of the receiver that meets the solution requirements; If the first position exists but the second position does not exist, determining the first position as the estimated position; If both the first position and the second position exist, the second position is determined as the estimated position.

3. The reconvergence method according to claim 2, characterized in that: The performing inter-epoch pseudorange differential positioning solution according to the first GNSS measurement data and the second GNSS measurement data to determine whether there is a first position of the receiver that meets the solution requirements includes: For each of the target satellites, a first pseudorange undifferenced observation equation of a current epoch is determined according to the first GNSS measurement data, and a second pseudorange undifferenced observation equation of a previous valid epoch is determined according to the second GNSS measurement data; According to the first pseudorange non-difference observation equation and the second pseudorange non-difference observation equation, for each of the target satellites, a pseudorange single-difference observation equation is determined by performing differential processing according to a preset differential rule based on the pseudorange non-difference observation equation between two epochs corresponding to the same target satellite; One of the target satellites is used as a reference satellite, and the pseudo-range single-difference observation equation corresponding to the reference satellite and the pseudo-range single-difference observation equations corresponding to the remaining target satellites are subjected to a second difference process according to a preset difference rule to determine a pseudo-range double-difference model; Constructing a first target matrix according to all pseudorange double-difference models; Performing least squares parameter estimation based on the first target matrix, determining the first inter-epoch position difference and the first least squares parameter estimation index; If the first least squares parameter estimation index is less than the first threshold, the first epoch position difference is the first epoch target position difference; The historical position of the receiver determined according to the second GNSS measurement data is updated using the first inter-epoch target position difference to determine a first position of the receiver at a current epoch.

4. The reconvergence method according to claim 3, characterized in that: If the first least squares parameter estimation index is not less than the first threshold, the first position is determined by the following steps: Eliminate pseudorange observation values ​​that meet a first elimination condition in the first GNSS measurement data and the second GNSS measurement data; If the total number of remaining pseudorange observation values ​​is not less than the first total number threshold, the iterative calculation of the first position is re-executed based on the remaining first GNSS measurement data and the second GNSS measurement data.

5. The reconvergence method according to claim 2, characterized in that: The performing inter-epoch carrier phase differential positioning solution according to the first GNSS measurement data and the second GNSS measurement data to determine whether there is a second position of the receiver that meets the solution requirements includes: For each of the target satellites, a first carrier phase undifference observation equation of a current epoch is determined according to the first GNSS measurement data, and a second carrier phase undifference observation equation of a previous valid epoch is determined according to the second GNSS measurement data; According to the first carrier phase non-difference observation equation and the second carrier phase non-difference observation equation, for each of the target satellites, a carrier phase single-difference observation equation is determined by performing differential processing according to a preset differential rule based on the carrier phase non-difference observation equation between two epochs corresponding to the same target satellite; One of the target satellites is used as a reference satellite, and the carrier phase single-difference observation equation corresponding to the reference satellite and the carrier phase single-difference observation equations corresponding to the remaining target satellites are subjected to difference processing one by one according to a preset difference rule to determine a carrier phase double-difference model; Constructing a second target matrix according to all carrier phase double difference models; Performing least squares parameter estimation based on the second target matrix to determine the second epoch position difference and the second least squares parameter estimation index; If the second least squares parameter estimation index is less than the second threshold, the second epoch position difference is the second epoch target position difference; The historical position of the receiver determined according to the second GNSS measurement data is updated using the target position difference between the second epochs to determine the second position of the receiver in the current epoch.

6. The reconvergence method according to claim 5, characterized in that: If the second least squares parameter estimation index is not less than the second threshold, the second position is determined by the following steps: Eliminate carrier phase observation values ​​that meet a second elimination condition in the first GNSS measurement data and the second GNSS measurement data; If the total number of remaining carrier phase observation values ​​is not less than the second total number threshold, the iterative calculation of the second position is re-executed based on the remaining first GNSS measurement data and the second GNSS measurement data.

7. A reconvergence device for precise single-point positioning, characterized in that: The reconvergence device comprises: An acquisition module, used for acquiring the first GNSS measurement data of the current epoch and the second GNSS measurement data of the previous valid epoch after the signal is restored, and determining the differential age between the two; A first determination module is used to perform inter-epoch differential positioning solution according to the first GNSS measurement data and the second GNSS measurement data to determine the estimated position of the receiver if the differential age is not greater than the age threshold; wherein the differential positioning solution includes inter-epoch pseudorange differential positioning solution and inter-epoch carrier phase differential positioning solution; A second determination module is used to determine initial state parameters required for precise point positioning update according to the first GNSS measurement data, the second GNSS measurement data and the estimated position; the initial state parameters include a receiver position correction number, and the receiver position correction number is determined according to the estimated position; The first processing module is used to perform filtering and solving processing according to the initial state parameters and the precise point positioning observation equation to determine the target position of the receiver.

8. The reconvergence device according to claim 7, characterized in that: When the first determination module is used to perform inter-epoch differential positioning solution based on the first GNSS measurement data and the second GNSS measurement data to determine the estimated position of the receiver, the first determination module is used to: Perform inter-epoch pseudorange differential positioning solution based on the first GNSS measurement data and the second GNSS measurement data to determine whether there is a first position of the receiver that meets the solution requirements; If the first position exists, performing inter-epoch carrier phase differential positioning solution according to the first GNSS measurement data and the second GNSS measurement data to determine whether there is a second position of the receiver that meets the solution requirements; If the first position exists but the second position does not exist, determining the first position as the estimated position; If both the first position and the second position exist, the second position is determined as the estimated position.

9. An electronic device, characterized in that: include: A processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor and the memory communicate through the bus, and the machine-readable instructions are executed by the processor to execute the steps of the re-convergence method as described in any one of claims 1 to 6.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the re-convergence method according to any one of claims 1 to 6 are executed.

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