Precise point positioning method and system based on broadcast ephemeris satellite clock speed prediction

Abstract

The present invention provides a precise point positioning method and system based on broadcast ephemeris satellite clock speed prediction, comprising the following steps: collecting broadcast ephemeris clock speed data, filtering the broadcast ephemeris clock speed data using a dynamic sliding window; preprocessing the filtered broadcast ephemeris clock speed data, eliminating abnormal state data, and obtaining preprocessed broadcast ephemeris clock speed data; adopting a linear periodic combination model, fitting the preprocessed broadcast ephemeris clock speed data using a least squares method, obtaining a fitted clock speed model for each satellite, and obtaining a satellite clock speed prediction value based on the fitted clock speed model; calculating, based on the satellite clock speed prediction value and in combination with user information and satellite information, a user equivalent ranging error of a satellite orbit and clock difference jump when the broadcast ephemeris of each satellite is updated; applying the user equivalent ranging error to precise point positioning data for solution and adjustment, and obtaining a corrected precise point positioning result.

Description

Technical Field

[0001] The present invention relates to the field of satellite navigation technology, and in particular to a precise single-point positioning method and system based on broadcast ephemeris satellite clock speed prediction. Background Art

[0002] In satellite navigation systems, high-precision satellite orbits and clock errors are a prerequisite for achieving Precise Point Positioning (PPP). Traditional PPP relies primarily on post-processed precise ephemeris or real-time high-precision products. In recent years, with the continuous improvement in the accuracy of broadcast ephemeris from major satellite navigation systems, PPP technology based on broadcast ephemeris has become increasingly feasible.

[0003] The broadcast ephemeris of a satellite navigation system primarily includes information such as time, orbital elements, clock errors, clock velocity, and clock drift provided by each satellite. This information is used by ground users to calculate satellite position and clock errors. Currently, satellite clock parameters in the broadcast ephemeris are typically updated and injected into the satellites periodically by ground control stations. The Beidou system's broadcast ephemeris is currently updated every hour. However, because the satellite clock errors in the broadcast ephemeris are predicted products and are affected by various factors (such as hardware errors, environmental changes, satellite frequency modulation, and cycle slips), the clock error parameters (such as clock error, clock velocity, and clock drift) in the broadcast ephemeris have limited accuracy and cannot fully reflect the actual deviation of the satellite clock, thus affecting the user's PPP positioning accuracy. Furthermore, due to processing strategies and other factors during broadcast ephemeris updates, the predicted satellite orbits and clock errors may experience jumps, which can cause jumps in PPP positioning and, in severe cases, even cause divergence in the positioning filter processing.

[0004] To improve the accuracy of PPP data processing based on broadcast ephemeris, and thus enhance positioning and timing accuracy, it is necessary to optimize and predict the broadcast ephemeris clock error. However, given that the satellite clocks in orbit may experience significant changes due to unexpected events such as satellite clock phase and frequency modulation, the key issue in improving the accuracy of PPP positioning and timing based on broadcast ephemeris is how to use accurate prediction models to predict and optimize the clock parameters in the broadcast ephemeris, improve the accuracy of the broadcast ephemeris clock error, and be able to adjust the model in real time to address anomalies such as satellite clock phase and frequency modulation. Summary of the Invention

[0005] This invention provides a precise point positioning method and system based on broadcast ephemeris satellite clock rate predictions, addressing existing technical deficiencies. By fitting and predicting satellite clock rate parameters within a dynamic sliding window, the accuracy of the broadcast ephemeris predicted clock error is improved. Furthermore, based on the predicted satellite clock error, the PPP processing model is optimized to improve PPP positioning and timing accuracy.

[0006] In a first aspect, the present invention provides a precise point positioning method based on broadcast ephemeris satellite clock rate prediction, comprising:

[0007] collecting broadcast ephemeris clock speed data, and filtering the broadcast ephemeris clock speed data using a dynamic sliding window;

[0008] Preprocessing the filtered broadcast ephemeris clock speed data to remove abnormal state data to obtain preprocessed broadcast ephemeris clock speed data;

[0009] Using a linear periodic combination model and a least squares method to fit the preprocessed broadcast ephemeris clock speed data, a fitted clock speed model for each satellite is obtained, and a satellite clock speed prediction value is obtained based on the fitted clock speed model;

[0010] Based on the satellite clock speed prediction value, combined with user information and satellite information, the user equivalent ranging error of the satellite orbit and clock error jump when each satellite broadcast ephemeris is updated is calculated. The user equivalent ranging error is applied to the precise single point positioning data for solution and adjustment to obtain the corrected precise single point positioning result.

[0011] According to a precise point positioning method based on broadcast ephemeris satellite clock speed prediction provided by the present invention, broadcast ephemeris clock speed data is collected and filtered using a dynamic sliding window, including:

[0012] Obtain real-time broadcast ephemeris clock speed data through the preset data transmission port;

[0013] The time length of the dynamic sliding window is determined, the broadcast ephemeris clock speed data is stored in the dynamic sliding window, and the data exceeding the time length of the dynamic sliding window is deleted to obtain filtered broadcast ephemeris clock speed data.

[0014] According to a precise point positioning method based on broadcast ephemeris satellite clock speed prediction provided by the present invention, filtered broadcast ephemeris clock speed data is preprocessed to remove abnormal state data to obtain preprocessed broadcast ephemeris clock speed data, including:

[0015] Determine the measured clock speed value of each satellite at any time from the filtered broadcast ephemeris clock speed data, obtain the clock error prediction value of each satellite at any time obtained by the satellite clock error fitting model, and eliminate abnormal state data based on the residual standard deviation of the measured clock speed value at any time and the clock error prediction value at any time;

[0016] The data without abnormal conditions is fitted piecewise, and the data is adjusted according to whether satellite clock error frequency modulation occurs to obtain the pre-processed broadcast ephemeris clock speed data.

[0017] According to a precise point positioning method based on broadcast ephemeris satellite clock rate prediction provided by the present invention, the measured clock rate value of each satellite at any time is determined from filtered broadcast ephemeris clock rate data, a clock error prediction value of each satellite at any time is obtained from a satellite clock error fitting model, and abnormal state data is eliminated based on the residual standard deviation of the measured clock rate value at any time and the clock error prediction value at any time, including:

[0018]

[0019] in, is the residual, yes The measured speed value at the moment, yes Clock error forecast value at the current time;

[0020] Based on residual Get the residual standard deviation of the satellite clock speed fitting model:

[0021]

[0022] in, is the number of valid data in the sliding window, is the residual standard deviation, is the mean residual;

[0023] Using preset thresholds Eliminate abnormal status data:

[0024]

[0025] in, The preset multiple.

[0026] According to a precise point positioning method based on broadcast ephemeris satellite clock rate prediction provided by the present invention, segmented fitting is performed on data excluding abnormal conditions, and data adjustment is performed based on whether satellite clock error frequency modulation occurs to obtain pre-processed broadcast ephemeris clock rate data, including:

[0027] Determine the fitted linear model for each segment of data:

[0028]

[0029] in, Represents the number of segments, represents the intercept, represents the slope, Represents the linear model function for fitting a single segment of data;

[0030] Compute the differences between intercepts and slopes of adjacent segments:

[0031]

[0032]

[0033] in, is the slope difference, is the intercept difference;

[0034] like or If the corresponding thresholds are exceeded, it is determined that the current satellite has undergone satellite clock frequency modulation, the historical data in the dynamic sliding window of the current satellite is cleared, and the data is accumulated again in the dynamic sliding window to form the pre-processed broadcast ephemeris clock speed data.

[0035] According to a precise point positioning method based on broadcast ephemeris satellite clock rate prediction provided by the present invention, a linear periodic combination model is adopted to fit the preprocessed broadcast ephemeris clock rate data using the least squares method to obtain a fitted clock rate model for each satellite, and a satellite clock rate prediction value is obtained based on the fitted clock rate model, including:

[0036] Construct a linear periodic combination model:

[0037]

[0038] in, is the initial clock rate deviation, is the observed clock speed, It's a cycle. 、 and is the coefficient;

[0039] The observation equation is established for n epoch observation data, then:

[0040]

[0041] Using the least squares method:

[0042]

[0043] in, is the observation matrix, is the observation vector, is the residual vector, are the components of the observation vector;

[0044] Obtain epoch observation data through least squares solution The optimal parameter estimate of :

[0045] .

[0046] According to the present invention, a precise point positioning method based on broadcast ephemeris satellite clock speed prediction is provided, which obtains a satellite clock speed prediction value based on a fitted clock speed model, including:

[0047] Determining the future using a fitted clock speed model The speed of time :

[0048] use Replace the clock speed parameters in the broadcast ephemeris to obtain new clock speed parameters :

[0049] .

[0050] According to a precise point positioning method based on broadcast ephemeris satellite clock rate prediction provided by the present invention, the user equivalent ranging error of the satellite orbit and clock error jump when each satellite broadcast ephemeris is updated is calculated based on the satellite clock rate prediction value, combined with user information and satellite information. The user equivalent ranging error is applied to the precise point positioning data for solution and adjustment to obtain a corrected precise point positioning result, including:

[0051] Based on the satellite clock speed prediction value, combined with the user's approximate position and the broadcast ephemeris orbit clock error, the user equivalent ranging error of the satellite orbit and clock error jump when the broadcast ephemeris of each satellite is updated is calculated:

[0052]

[0053] in, is the user equivalent ranging error caused by the broadcast ephemeris update, and are the geometric distances calculated for any two sets of parameters and user positions before and after the broadcast ephemeris update;

[0054] Depend on Get the accumulated user equivalent ranging error:

[0055]

[0056] in, is the accumulated user equivalent ranging error, is the number of broadcast ephemeris updates;

[0057] Will Converted into carrier phase ambiguity correction :

[0058]

[0059] in, is the carrier wavelength;

[0060] Based on the GNSS observation equation, precise single-point positioning is solved using root mean square information filtering to obtain the precise single-point solution position and receiver clock difference based on the broadcast ephemeris satellite clock rate forecast.

[0061] In a second aspect, the present invention further provides a precise point positioning system based on broadcast ephemeris satellite clock rate prediction, comprising:

[0062] An acquisition module, configured to acquire broadcast ephemeris clock speed data and filter the broadcast ephemeris clock speed data using a dynamic sliding window;

[0063] A preprocessing module is used to preprocess the filtered broadcast ephemeris clock speed data, remove abnormal state data, and obtain preprocessed broadcast ephemeris clock speed data;

[0064] A fitting module is used to fit the preprocessed broadcast ephemeris clock speed data using a least squares method using a linear periodic combination model to obtain a fitted clock speed model for each satellite, and obtain a satellite clock speed prediction value based on the fitted clock speed model;

[0065] A solution module is used to calculate the user equivalent ranging error of the satellite orbit and clock error jump when each satellite broadcast ephemeris is updated based on the satellite clock rate prediction value, combined with user information and satellite information, and apply the user equivalent ranging error to the precise single point positioning data for solution adjustment to obtain a corrected precise single point positioning result.

[0066] In a third aspect, the present invention also provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the precise single-point positioning method based on broadcast ephemeris satellite clock rate prediction as described above is implemented.

[0067] The present invention provides a precise single-point positioning method and system based on broadcast ephemeris satellite clock rate prediction. By using only GNSS broadcast ephemeris for PPP solution, high-precision positioning is ensured while avoiding reliance on high-precision satellite orbit clock error products. A linear + periodic term function model is used to fit GNSS broadcast ephemeris clock rate parameters, thereby improving the accuracy of broadcast ephemeris clock rate prediction. The broadcast ephemeris clock rate parameters predicted by the model are also used to compensate for the user equivalent distance error caused by broadcast ephemeris update, thereby improving the PPP data processing accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0069] Figure 1 This is one of the flow charts of the precise point positioning method based on broadcast ephemeris satellite clock rate prediction provided by the present invention;

[0070] Figure 2 This is the second flow chart of the precise point positioning method based on broadcast ephemeris satellite clock rate prediction provided by the present invention;

[0071] Figure 3 Schematic diagram of the structure of the precise point positioning system based on broadcast ephemeris satellite clock speed prediction provided by the present invention;

[0072] Figure 4 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0073] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0074] The present invention proposes a precise point positioning method based on broadcast ephemeris satellite clock rate prediction. First, the accuracy of broadcast ephemeris prediction clock error is improved by fitting and predicting the satellite clock rate parameters in a dynamic sliding window. Second, based on the predicted satellite clock error, the PPP processing model is optimized to improve the PPP positioning and timing accuracy.

[0075] Figure 1 This is one of the flow charts of the precise point positioning method based on broadcast ephemeris satellite clock rate prediction provided by an embodiment of the present invention, such as Figure 1 Shown, including:

[0076] Step 100: Collect broadcast ephemeris clock speed data, and filter the broadcast ephemeris clock speed data using a dynamic sliding window;

[0077] Step 200: pre-processing the filtered broadcast ephemeris clock speed data to remove abnormal state data to obtain pre-processed broadcast ephemeris clock speed data;

[0078] Step 300: Using a linear periodic combination model and a least squares method to fit the preprocessed broadcast ephemeris clock rate data, a fitted clock rate model for each satellite is obtained, and a satellite clock rate prediction value is obtained based on the fitted clock rate model.

[0079] Step 400: Based on the satellite clock rate prediction value, combined with user information and satellite information, calculate the user equivalent ranging error of the satellite orbit and clock error jump when each satellite broadcast ephemeris is updated, and apply the user equivalent ranging error to the precise single point positioning data for solution and adjustment to obtain the corrected precise single point positioning result.

[0080] Specifically, the core process of the method proposed in the embodiment of the present invention is shown in Figure 2 As shown in the figure, the core lies in fitting the satellite clock rate through a dynamic sliding window, optimizing the broadcast ephemeris clock error prediction, and ultimately improving the PPP data processing accuracy.

[0081] First, the latest broadcast ephemeris clock speed data of each satellite is collected in real time. According to the dynamic sliding window method, the broadcast ephemeris clock speed data of each satellite is stored in the memory, and the data outside the sliding window size is deleted.

[0082] Then, independent data preprocessing is performed on each satellite, and special situations such as frequency modulation and outliers of the real-time satellite clock error are identified using information such as forecast residuals. Quality control operations such as downgrading and elimination are performed on abnormal broadcast ephemeris clock speed data.

[0083] Next, based on the preprocessed broadcast ephemeris clock speed data of each satellite, a linear + periodic term model is used to independently fit the clock speed model of each satellite using least squares, and the predicted satellite clock speed value at the current moment is obtained based on the fitted clock speed model.

[0084] Finally, based on the predicted satellite clock speed, combined with the user's approximate position, the number of broadcast ephemeris orbit elements, satellite clock error, etc., the equivalent ranging error of the user caused by the satellite orbit and clock error jump when each satellite broadcast ephemeris is updated is calculated, and it is corrected into the PPP data processing to improve the PPP positioning and timing accuracy.

[0085] The present invention fits the satellite clock rate through a dynamic sliding window, optimizes the broadcast ephemeris clock error prediction, and ultimately improves the PPP data processing accuracy.

[0086] In one embodiment, step 100 includes:

[0087] Obtain real-time broadcast ephemeris clock error and velocity data through serial ports, etc.

[0088] Determine the length of the dynamic sliding window (e.g., 5 days). It's important to note that the length of the dynamic sliding window has a certain impact on modeling accuracy and real-time performance. If the window is too long, the model will lag and fail to reflect the latest clock rate changes. If the window is too short, insufficient data may reduce fitting stability. Once the time length is determined, the latest broadcast ephemeris clock rate data can be stored in the sliding window. Each time a new set of broadcast ephemeris clock rate data is received, it is immediately stored in the corresponding satellite's sliding window queue. The system automatically checks the timeliness of the oldest data in the queue. If it exceeds the window length, the data outside the sliding window (i.e., data that exceeds the time length) is deleted.

[0089] In one embodiment, step 200 includes:

[0090] Since satellite clock speed data may contain errors due to signal interference, receiver noise, and satellite clock anomalies, we perform independent data preprocessing on each satellite. We compare the difference between the predicted clock speed and the current data. The residual between the predicted and current data is then compared with the standard deviation of the residuals from the satellite clock speed fitting model. Values ​​exceeding five times the standard deviation are considered outliers and are marked and removed.

[0091] The residual between the clock speed forecast and the current data:

[0092] (1)

[0093] in is the residual, yes The measured speed value at the time, yes The clock error forecast value at the time.

[0094] Residual standard deviation of the satellite clock rate fitting model:

[0095] (2)

[0096] Where N is the number of valid data in the sliding window, is the residual standard deviation, is the residual mean. The threshold is set as:

[0097] (3)

[0098] in, It is a preset multiple, and in the embodiment of the present invention, it is usually set to 5.

[0099] Satellite clocks may experience frequency jumps, also known as frequency modulation, due to manual adjustments by the ground control station or hardware failures. This is manifested as a step-like change in the clock speed parameters. Therefore, frequency modulation detection is performed here. The specific method is to segment the satellite clock speed and then fit each segment. Based on the model coefficients of the segmented fitting, it is further determined whether the satellite clock error frequency modulation has occurred.

[0100] Fit a linear model to each segment of data:

[0101] (4)

[0102] in, Represents the number of segments, represents the intercept, represents the slope, Represents the linear model function for fitting a single segment of data;

[0103] Calculate the difference in slopes of adjacent segments:

[0104]

[0105] (5)

[0106] in, is the slope difference, is the intercept difference;

[0107] if or , exceeds the threshold, it is determined that satellite clock error frequency modulation has occurred at this moment.

[0108] At this time, if it is determined that satellite clock frequency modulation has occurred, the historical data in the satellite sliding window will be immediately cleared and the data will be accumulated again according to the sliding window.

[0109] In one embodiment, step 300 includes:

[0110] After obtaining the pre-processed broadcast ephemeris clock rate data, a linear + periodic term combination model is established, and the least squares method is used to independently fit the clock rate data of each satellite, and high-precision clock rate prediction is achieved based on the fitting model.

[0111] Model construction: (6)

[0112] in is the initial clock rate deviation, is the observed clock speed, It's a cycle. 、 and is the coefficient. The observation equation is established for n epoch observation data, then:

[0113] (7)

[0114] Least Squares Method:

[0115] (8)

[0116] in is the observation matrix, is the observation vector, is the residual vector, are the components of the observation vector. Finally, the epoch observation data is obtained by least squares solution The optimal parameter estimate of :

[0117] (9)

[0118] Furthermore, a predicted satellite clock speed value at the current moment is obtained based on the fitted clock speed model, and the predicted satellite clock speed value is used to update the satellite clock speed parameters in the broadcast ephemeris.

[0119] Extrapolating the fitted model into the future Clock speed of time:

[0120] (10)

[0121] use Replace the clock rate parameter in the broadcast ephemeris:

[0122] (11)

[0123] In one embodiment, step 400 includes:

[0124] Based on the predicted satellite clock speed, combined with the user's approximate position, broadcast ephemeris orbit and clock error parameters, the user's equivalent ranging error caused by the satellite orbit and clock error jump when the satellite broadcast ephemeris is updated is calculated:

[0125] (12)

[0126] in is the equivalent ranging error caused by the broadcast ephemeris update, and The geometric distances calculated for any two sets of parameters and user positions before and after the broadcast ephemeris update.

[0127] When a user continuously observes the same satellite, there may be multiple broadcast ephemeris updates, and the accumulated user equivalent ranging error can be obtained:

[0128] (13)

[0129] in, is the accumulated user equivalent ranging error, The number of broadcast ephemeris updates.

[0130] Considering that the equivalent ranging error during broadcast ephemeris update mainly affects the continuity of the ambiguity parameters of the phase observation, in order to avoid the influence of long-term error accumulation on the pseudorange observation, only the accumulated value of the user equivalent ranging error is corrected to the ambiguity parameter of the phase. When a cycle slip occurs in the user phase observation, the accumulated value of the user equivalent ranging error correction is cleared.

[0131] Will Converted into carrier phase ambiguity correction :

[0132]

[0133] in, is the carrier wavelength.

[0134] Finally, based on the GNSS observation equation, PPP solution is performed using root mean square information filtering to obtain the PPP solution position and receiver clock error based on the broadcast ephemeris satellite clock rate forecast, thereby improving the positioning and timing accuracy.

[0135] The precise single-point positioning system based on broadcast ephemeris satellite clock speed forecast provided by the present invention is described below. The precise single-point positioning system based on broadcast ephemeris satellite clock speed forecast described below and the precise single-point positioning method based on broadcast ephemeris satellite clock speed forecast described above can be referenced to each other.

[0136] Figure 3 FIG is a structural diagram of a precise point positioning system based on broadcast ephemeris satellite clock speed prediction provided by an embodiment of the present invention. Figure 3 As shown, it includes: an acquisition module 31, a pre-processing module 32, a fitting module 33 and a solution module 34, wherein:

[0137] The acquisition module 31 is used to collect broadcast ephemeris clock speed data and filter the broadcast ephemeris clock speed data using a dynamic sliding window; the preprocessing module 32 is used to preprocess the filtered broadcast ephemeris clock speed data, eliminate abnormal state data, and obtain preprocessed broadcast ephemeris clock speed data; the fitting module 33 is used to adopt a linear periodic combination model and use the least squares method to fit the preprocessed broadcast ephemeris clock speed data to obtain a fitted clock speed model for each satellite, and obtain the satellite clock speed prediction value based on the fitted clock speed model; the solution module 34 is used to calculate the user equivalent ranging error of the satellite orbit and clock difference jump when the broadcast ephemeris of each satellite is updated based on the satellite clock speed prediction value, combined with user information and satellite information, and apply the user equivalent ranging error to the precise single point positioning data for solution and adjustment to obtain the corrected precise single point positioning result.

[0138] Figure 4 An example of a physical structure diagram of an electronic device is shown below. Figure 4 As shown, the electronic device may include: a processor (processor) 410, a communication interface (Communications Interface) 420, a memory (memory) 430 and a communication bus 440, wherein the processor 410, the communication interface 420, and the memory 430 communicate with each other through the communication bus 440. The processor 410 can call the logic instructions in the memory 430 to execute a precise point positioning method based on the broadcast ephemeris satellite clock rate prediction, the method including: collecting broadcast ephemeris clock rate data, filtering the broadcast ephemeris clock rate data using a dynamic sliding window; preprocessing the filtered broadcast ephemeris clock rate data to eliminate abnormal state data to obtain preprocessed broadcast ephemeris clock rate data; using a linear periodic combination model and a least squares method to fit the preprocessed broadcast ephemeris clock rate data to obtain a fitted clock rate model for each satellite, and obtaining a satellite clock rate prediction value based on the fitted clock rate model; according to the satellite clock rate prediction value, combined with user information and satellite information, calculating the user equivalent ranging error of the satellite orbit and clock error jump when the broadcast ephemeris of each satellite is updated, applying the user equivalent ranging error to the precise point positioning data for solution and adjustment, and obtaining a corrected precise point positioning result.

[0139] Furthermore, the logic instructions in the aforementioned memory 430 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product, stored in a storage medium, includes instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a mobile hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0140] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0141] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods described in each embodiment or certain portions of the embodiments.

[0142] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A precise point positioning method based on broadcast ephemeris satellite clock rate prediction, characterized in that: include: Collecting broadcast ephemeris clock speed data, and filtering the broadcast ephemeris clock speed data using a dynamic sliding window; Preprocessing the filtered broadcast ephemeris clock speed data to remove abnormal state data to obtain preprocessed broadcast ephemeris clock speed data; Using a linear periodic combination model and a least squares method to fit the preprocessed broadcast ephemeris clock speed data, a fitted clock speed model for each satellite is obtained, and a satellite clock speed prediction value is obtained based on the fitted clock speed model; Based on the satellite clock speed prediction value, combined with user information and satellite information, the user equivalent ranging error of the satellite orbit and clock error jump when each satellite broadcast ephemeris is updated is calculated. The user equivalent ranging error is applied to the precise single point positioning data for solution and adjustment to obtain the corrected precise single point positioning result.

2. The precise point positioning method based on broadcast ephemeris satellite clock rate prediction according to claim 1, characterized in that: Collecting broadcast ephemeris clock speed data and filtering the broadcast ephemeris clock speed data using a dynamic sliding window, including: Obtain real-time broadcast ephemeris clock speed data through the preset data transmission port; The time length of the dynamic sliding window is determined, the broadcast ephemeris clock speed data is stored in the dynamic sliding window, and the data exceeding the time length of the dynamic sliding window is deleted to obtain filtered broadcast ephemeris clock speed data.

3. The precise point positioning method based on broadcast ephemeris satellite clock rate prediction according to claim 1, characterized in that: The filtered broadcast ephemeris clock speed data is preprocessed to remove abnormal state data to obtain preprocessed broadcast ephemeris clock speed data, including: Determine the measured clock speed value of each satellite at any time from the filtered broadcast ephemeris clock speed data, obtain the clock error prediction value of each satellite at any time obtained by the satellite clock error fitting model, and eliminate abnormal state data based on the residual standard deviation of the measured clock speed value at any time and the clock error prediction value at any time; The data without abnormal conditions is fitted piecewise, and the data is adjusted according to whether satellite clock error frequency modulation occurs to obtain the pre-processed broadcast ephemeris clock speed data.

4. The precise point positioning method based on broadcast ephemeris satellite clock rate prediction according to claim 3, characterized in that: Determine the measured clock speed value of each satellite at any time from the filtered broadcast ephemeris clock speed data, obtain the clock error prediction value of each satellite at any time obtained by the satellite clock error fitting model, and eliminate abnormal state data based on the residual standard deviation of the measured clock speed value at any time and the clock error prediction value at any time, including: in, is the residual, yes The measured speed value at the moment, yes Clock error forecast value at the current time; Based on residual Get the residual standard deviation of the satellite clock speed fitting model: in, is the number of valid data in the sliding window, is the residual standard deviation, is the residual mean; Using preset thresholds Eliminate abnormal status data: in, The preset multiple.

5. The precise point positioning method based on broadcast ephemeris satellite clock rate prediction according to claim 4, characterized in that: Perform segmented fitting on the data excluding abnormal conditions, adjust the data according to whether satellite clock error frequency modulation occurs, and obtain the pre-processed broadcast ephemeris clock speed data, including: Determine the fitted linear model for each segment of data: in, Indicates the number of segments, represents the intercept, represents the slope, Represents the linear model function for fitting a single segment of data; Compute the differences between intercepts and slopes of adjacent segments: in, is the slope difference, is the intercept difference; like or If the corresponding thresholds are exceeded, it is determined that the current satellite has undergone satellite clock frequency modulation, the historical data in the dynamic sliding window of the current satellite is cleared, and the data is accumulated again in the dynamic sliding window to form the pre-processed broadcast ephemeris clock speed data.

6. The precise point positioning method based on broadcast ephemeris satellite clock rate prediction according to claim 1, characterized in that: A linear periodic combination model is used to fit the preprocessed broadcast ephemeris clock rate data using the least squares method to obtain a fitted clock rate model for each satellite, and a satellite clock rate prediction value is obtained based on the fitted clock rate model, including: Construct a linear periodic combination model: in, is the initial clock rate deviation, is the observed clock speed, It's a cycle. 、 and is the coefficient; The observation equation is established for n epoch observation data, then: Using the least squares method: in, is the observation matrix, is the observation vector, is the residual vector, are the components of the observation vector; Obtain epoch observation data through least squares solution The optimal parameter estimate of : 。 7. The precise point positioning method based on broadcast ephemeris satellite clock rate prediction according to claim 6, wherein: Obtain satellite clock speed predictions based on the fitted clock speed model, including: Determining the future using a fitted clock speed model The speed of time : use Replace the clock speed parameters in the broadcast ephemeris to obtain new clock speed parameters : 。 8. The precise point positioning method based on broadcast ephemeris satellite clock rate prediction according to claim 1, characterized in that: Based on the satellite clock rate prediction value, combined with user information and satellite information, the user equivalent ranging error of the satellite orbit and clock error jump when each satellite broadcast ephemeris is updated is calculated, and the user equivalent ranging error is applied to the precise point positioning data for solution and adjustment to obtain the corrected precise point positioning result, including: Based on the satellite clock speed prediction value, combined with the user's approximate position and the broadcast ephemeris orbit clock error, the user equivalent ranging error of the satellite orbit and clock error jump when the broadcast ephemeris of each satellite is updated is calculated: in, is the user equivalent ranging error caused by the broadcast ephemeris update, and are the geometric distances calculated for any two sets of parameters and user positions before and after the broadcast ephemeris update; Depend on Get the accumulated user equivalent ranging error: in, is the accumulated user equivalent ranging error, is the number of broadcast ephemeris updates; Will Converted into carrier phase ambiguity correction : in, is the carrier wavelength; Based on the GNSS observation equation, precise single-point positioning is solved using root mean square information filtering to obtain the precise single-point solution position and receiver clock difference based on the broadcast ephemeris satellite clock rate forecast.

9. A precise point positioning system based on broadcast ephemeris satellite clock speed prediction, characterized in that: include: An acquisition module, configured to acquire broadcast ephemeris clock speed data and filter the broadcast ephemeris clock speed data using a dynamic sliding window; A preprocessing module is used to preprocess the filtered broadcast ephemeris clock speed data, remove abnormal state data, and obtain preprocessed broadcast ephemeris clock speed data; A fitting module is used to fit the preprocessed broadcast ephemeris clock speed data using a least squares method using a linear periodic combination model to obtain a fitted clock speed model for each satellite, and obtain a satellite clock speed prediction value based on the fitted clock speed model; A solution module is used to calculate the user equivalent ranging error of the satellite orbit and clock error jump when each satellite broadcast ephemeris is updated based on the satellite clock rate prediction value, combined with user information and satellite information, and apply the user equivalent ranging error to the precise single point positioning data for solution adjustment to obtain a corrected precise single point positioning result.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the precise point positioning method based on broadcast ephemeris satellite clock rate prediction as described in any one of claims 1 to 8 is implemented.

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