Method for correcting cycle slip of carrier phase, electronic device, storage medium and product

Abstract

This application relates to the field of satellite positioning technology and discloses a carrier phase cycle slip correction method, electronic device, storage medium, and product, including: determining the cycle slip number of a first frequency point with a large cycle slip based on the Doppler frequency offset of each frequency point in the current epoch, the Doppler frequency offset of the previous epoch, the carrier phase of the current epoch, and the carrier phase of the previous epoch; obtaining a first carrier phase correction value for the current epoch based on the cycle slip number of the first frequency point; constructing a small cycle slip estimation model based on the first carrier phase correction value to determine the cycle slip number of a second frequency point with a small cycle slip among all frequency points; obtaining a second carrier phase correction value based on the cycle slip number of the first frequency point and the cycle slip number of the second frequency point; and determining the target carrier phase based on the satellite motion state information of the target satellite, the receiver motion state information of the receiver, and the second carrier phase correction value to ensure the repair accuracy of carrier phase observations in the fusion scenario of low-Earth orbit satellites and medium-Earth orbit satellites.

Description

Technical Field

[0001] This application relates to the field of satellite positioning technology, specifically to a carrier phase cycle slip correction method, electronic device, storage medium, and product. Background Technology

[0002] Carrier phase refers to the phase difference between the receiver's local oscillator reference signal and the satellite carrier signal. Carrier phase is the core data source for global navigation satellite systems to achieve high-precision satellite positioning. Due to signal blockage, multipath effect, ionospheric disturbance, receiver dynamic movement and other reasons, the carrier phase may experience integer cycle jumps, i.e., cycle jumps. Cycle jumps will cause integer ambiguity to be reinitialized, which will seriously affect the satellite positioning accuracy and convergence speed.

[0003] Existing carrier phase cycle slip correction methods are mainly designed for medium-Earth orbit (MEO) satellites. Low-Earth orbit (LEO) satellites have high dynamic characteristics, diverse signal frequencies, and drastic changes in observation geometry. The frequency and complexity of cycle slips in LEO satellites are much higher than those in MEO satellites. When existing carrier phase cycle slip correction methods are directly applied to the fusion scenario of LEO and MEO satellites, there are problems such as insufficient detection sensitivity and low repair success rate. Summary of the Invention

[0004] The purpose of this application is to provide a carrier phase cycle slip correction method, electronic device, storage medium, and product to solve the problem that insufficient detection sensitivity and low repair success rate exist when the existing carrier phase cycle slip correction method is directly applied to the fusion scenario of low-Earth orbit satellites and medium-Earth orbit satellites.

[0005] To achieve the above objectives, the first aspect of this application provides a cycle slip correction method for carrier phase, the cycle slip correction method comprising: For all frequency points of the target satellite, based on the Doppler frequency offset of each frequency point in the current epoch, the Doppler frequency offset of the previous epoch, the carrier phase of the current epoch, and the carrier phase of the previous epoch, determine the cycle slip number of the first frequency point with a large cycle slip among all frequency points. The target satellite includes low-Earth orbit satellites and / or medium-Earth orbit satellites. Based on the cycle slip number of the first frequency point, the carrier phase of the first frequency point in the current epoch is corrected to obtain the first carrier phase correction value in the current epoch. Based on the first carrier phase correction value, a small cycle slip estimation model is constructed to determine the number of cycle slips at the second frequency point where small cycle slips occur among all frequency points; Based on the cycle slip count of the first frequency point and the cycle slip count of the second frequency point, the carrier phase of the first frequency point in the current epoch is corrected to obtain the second carrier phase correction value; The target carrier phase is determined based on the satellite motion status information of the target satellite, the receiver motion status information of the receiver, and the second carrier phase correction value.

[0006] In this embodiment of the application, based on the Doppler frequency offset of each frequency point in the current epoch, the Doppler frequency offset of the previous epoch, the carrier phase of the current epoch, and the carrier phase of the previous epoch, the cycle slip number of the first frequency point where a large cycle slip occurs among all frequency points is determined, including: Based on the Doppler frequency offset of the frequency point in the current epoch and the Doppler frequency offset of the previous epoch, the Doppler frequency offset integral phase is obtained. Based on the carrier phase of the current epoch and the carrier phase of the previous epoch, the carrier phase change is obtained. Based on the Doppler frequency offset integral phase and the carrier phase change, the phase difference between the Doppler frequency offset integral phase and the carrier phase change is obtained; Based on the phase difference value and the preset phase difference value threshold, determine the cycle slip number of the first frequency point where a large cycle slip occurs among all frequency points.

[0007] In this embodiment of the application, the cycle slip number of the first frequency point where a large cycle slip occurs among all frequency points is determined based on the phase difference value and a preset phase difference threshold, including: If the phase difference is greater than a preset phase difference threshold, determine the first frequency point where a large cycle jump occurs among all frequency points; The number of cycle jumps at the first frequency point is determined based on the phase difference.

[0008] In this embodiment of the application, the cycle slip correction method further includes: Obtain the epoch interval and initial difference threshold; Based on the Doppler frequency offset, epoch interval, and initial difference threshold of the target satellite at the current epoch, a preset phase difference threshold is determined.

[0009] In this embodiment of the application, a small cycle slip estimation model is constructed based on the first carrier phase correction value to determine the cycle slip number of the second frequency point where a small cycle slip occurs among all frequency points, including: Obtain the ionospheric delay value and carrier phase prediction value for the current epoch, wherein the carrier phase prediction value is predicted by the carrier phase prediction model; Based on the first carrier phase correction value and the ionospheric delay value, a generalized geometrically independent test quantity is constructed. Based on the first carrier phase correction value and the carrier phase prediction value, a multi-frequency adaptive weighted test quantity is constructed; Based on the generalized geometrically independent test quantifier, the multi-frequency adaptive weighted test quantifier, and the preset test quantifier range, the second frequency point where the small cycle slip occurs among all frequency points is determined. Based on the second frequency point, a small cycle slip estimation model is constructed; The number of cycle slips at the second frequency point is obtained by performing an integer search based on the small cycle slip estimation model.

[0010] In this embodiment of the application, the carrier phase of the first frequency point in the current epoch is corrected based on the cycle slip count of the first frequency point and the cycle slip count of the second frequency point to obtain the second carrier phase correction value, including: The sum of cycle slips is obtained based on the sum of the cycle slip counts at the first frequency point and the second frequency point; The second carrier phase correction value is determined based on the difference between the carrier phase and the cycle slip sum at the first frequency point in the current epoch.

[0011] In this embodiment of the application, the target carrier phase is determined based on the satellite motion state information of the target satellite, the receiver motion state information of the receiver, and the second carrier phase correction value, including: Based on satellite motion state information and receiver motion state information, determine the first distance between the satellite and the receiver; The change in the first distance from the previous epoch to the current epoch is taken as the first distance change value; Based on the second carrier phase correction value and the carrier phase of the previous epoch, the second distance change value between the satellite and the receiver is determined; The distance change difference is obtained based on the difference between the first distance change value and the second distance change value; If the difference in distance variation is less than a preset distance threshold, the second carrier phase correction value is determined as the target carrier phase.

[0012] A second aspect of this application provides an electronic device, comprising: The memory is configured to store instructions; The processor is configured to retrieve instructions from memory and, when executing instructions, to implement a cycle slip correction method for the carrier phase as provided in the first aspect above.

[0013] A third aspect of this application provides a machine-readable storage medium storing instructions for causing a machine to perform a cycle slip correction method for a carrier phase as provided in the first aspect above.

[0014] The fourth aspect of this application is a computer program product, which includes a computer program that, when executed by a processor, implements a cycle slip correction method for carrier phase as provided in the first aspect above.

[0015] The above technical solution firstly utilizes the physical relationship between Doppler frequency offset and carrier phase to achieve millisecond-level rapid identification of large cycle slips and obtain the first carrier phase correction value, avoiding the pollution of subsequent calculations by large cycle slips. Next, based on the first carrier phase correction value, a small cycle slip estimation model is constructed to accurately determine the cycle slip number at the second frequency point where the small cycle slip occurs. This number is then combined with the cycle slip number at the first frequency point to obtain the second carrier phase correction value, achieving comprehensive processing of both large and small cycle slips. Finally, the second carrier phase correction value is verified using satellite motion state information and receiver motion state information, ultimately determining an accurate and reliable target carrier phase. This meets the high dynamic real-time requirements of low-Earth orbit (LEO) and medium-Earth orbit (MEO) satellites, effectively ensuring the continuity and accuracy of carrier phase observations in the fusion scenario of LEO and MEO satellites.

[0016] Other features and advantages of the embodiments of this application will be described in detail in the following detailed description section. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the following detailed description to explain the embodiments of this application, but do not constitute a limitation on the embodiments of this application. In the drawings: Figure 1 The schematic diagram illustrates a flowchart of a carrier phase cycle slip correction method according to an embodiment of this application; Figure 2 A schematic diagram of an electronic device according to an embodiment of this application is shown. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for illustration and explanation of the embodiments of this application and are not intended to limit the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0019] It should be noted that the acquisition, transmission, storage, use, and processing of data in the technical solution of this application all comply with relevant laws and regulations. In the embodiments of this application, certain existing industry solutions such as software, components, and models may be mentioned. These should be considered exemplary, intended only to illustrate the feasibility of implementing the technical solution of this application, and do not imply that the applicant has already used or necessarily used such solutions.

[0020] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0021] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0022] Figure 1 The illustration shows a schematic flowchart of a carrier phase cycle slip correction method according to an embodiment of this application. Figure 1 As shown in the embodiment of this application, a cycle slip correction method for carrier phase is provided. The cycle slip correction method includes: Step S110: For all frequency points of the target satellite, based on the Doppler frequency offset of each frequency point in the current epoch, the Doppler frequency offset of the previous epoch, the carrier phase of the current epoch, and the carrier phase of the previous epoch, determine the cycle slip number of the first frequency point where a large cycle slip occurs among all frequency points, wherein the target satellite includes low-Earth orbit satellites and / or medium-Earth orbit satellites. Step S120: Based on the cycle slip number of the first frequency point, correct the carrier phase of the first frequency point in the current epoch to obtain the first carrier phase correction value in the current epoch; Step S130: Based on the first carrier phase correction value, construct a small cycle slip estimation model to determine the number of cycle slips at the second frequency point where small cycle slips occur among all frequency points; Step S140: Based on the cycle slip count of the first frequency point and the cycle slip count of the second frequency point, correct the carrier phase of the first frequency point in the current epoch to obtain the second carrier phase correction value; Step S150: Determine the target carrier phase based on the satellite motion state information of the target satellite, the receiver motion state information of the receiver, and the second carrier phase correction value.

[0023] In step S110, the target satellites include low-Earth orbit navigation satellites and / or medium-Earth orbit navigation satellites. Each frequency point corresponds to a signal frequency transmitted by a satellite. The epoch refers to the sampling time of the receiver. The Doppler frequency offset refers to the change in signal frequency caused by the relative motion between the satellite and the receiver. The carrier phase refers to the measured value of the carrier signal phase by the receiver. By using the Doppler frequency offset of each frequency point in the current epoch, the Doppler frequency offset of the previous epoch, the carrier phase of the current epoch, and the carrier phase of the previous epoch, the cycle slip number of the first frequency point where a large cycle slip occurs among all frequency points is determined.

[0024] In step S120, the carrier phase of the first frequency point in the current epoch is corrected by the cycle slip number of the first frequency point to obtain the first carrier phase correction value for the current epoch. The first carrier phase correction value for the current epoch is obtained by the following formula:

[0025] In the formula, This represents the first carrier phase correction value in the current epoch. This indicates the carrier phase of the first frequency point in the current epoch. This represents the cycle slip number at the first frequency point. The purpose of the correction is to temporarily remove the influence of large cycle slips from the carrier phase of the first frequency point in the current epoch, resulting in a cleaned-up correction value for the first carrier phase in the current epoch.

[0026] In step S130, this step constructs a small cycle slip estimation model for the first carrier phase correction value after coarse repair of large cycle slips. The purpose is to detect and estimate the number of cycle slips at the second frequency point where small cycle slips occur among all frequency points. The cycle slips of large cycle slips are greater than the cycle slips of small cycle slips.

[0027] In step S140, the cycle slip counts of the first frequency point and the second frequency point determined in the preceding steps are summed to obtain the total cycle slip count. Then, the carrier phase of the first frequency point in the current epoch is corrected again using the total cycle slip count to obtain the second carrier phase correction value. The second carrier phase correction value is obtained using the following formula:

[0028] In the formula, This represents the second carrier phase correction value. This indicates the number of cycle jumps at the second frequency point.

[0029] In step S150, the reliability of the repair result in step S140 is verified to ensure that the final output carrier phase observation value is true and reliable. This step makes full use of the advantage of the drastic geometric changes of the target satellite. By using the satellite motion state information, receiver motion state information and the second carrier phase correction value, the target carrier phase that has been successfully repaired is finally determined.

[0030] This application embodiment first utilizes the physical relationship between Doppler frequency offset and carrier phase to achieve millisecond-level rapid identification of large cycle slips and obtain a first carrier phase correction value, avoiding large cycle slips from polluting subsequent calculations. Next, based on the first carrier phase correction value, a small cycle slip estimation model is constructed to accurately determine the cycle slip number at the second frequency point where the small cycle slip occurs. This small cycle slip is then combined with the cycle slip number at the first frequency point to obtain a comprehensive correction value for the second carrier phase, achieving comprehensive processing of both large and small cycle slips. Finally, the second carrier phase correction value is verified using satellite motion state information and receiver motion state information, ultimately determining an accurate and reliable target carrier phase. This meets the high dynamic real-time requirements of low-Earth orbit (LEO) and medium-Earth orbit (MEO) satellites, effectively ensuring the continuity and accuracy of carrier phase observations in the fusion scenario of LEO and MEO satellites.

[0031] Furthermore, step S110 in this embodiment may include the following steps: Step S111: Based on the Doppler frequency offset of the frequency point in the current epoch and the Doppler frequency offset of the previous epoch, obtain the Doppler frequency offset integral phase; Step S112: Based on the carrier phase of the current epoch and the carrier phase of the previous epoch, obtain the carrier phase change. Step S113: Based on the Doppler frequency offset integral phase and the carrier phase change, obtain the phase difference between the Doppler frequency offset integral phase and the carrier phase change; Step S114: Determine the cycle slip number of the first frequency point where a large cycle slip occurs among all frequency points based on the phase difference value and the preset phase difference value threshold.

[0032] In step S111, the carrier phase change is obtained by combining the carrier phase of the current epoch and the carrier phase of the previous epoch. The Doppler frequency offset integral phase is determined by the following formula:

[0033]

[0034] In the formula, Indicates the Doppler frequency offset integral phase. This indicates the Doppler frequency offset of the current epoch. This indicates the Doppler frequency offset of the previous epoch. Indicates the epoch interval. Indicates the current epoch. Indicates the previous epoch.

[0035] In step S112, the carrier phase change is obtained by the difference between the carrier phase of the current epoch and the carrier phase of the previous epoch. The carrier phase change is determined by the following formula:

[0036] In the formula, This indicates the amount of carrier phase change. This indicates the carrier phase of the previous epoch.

[0037] In step S113, the absolute value of the difference between the carrier phase change and the Doppler frequency offset integral phase is taken as the phase difference value. The phase difference value is determined by the following formula:

[0038] In the formula, This represents the phase difference.

[0039] In step S114, the relationship between the phase difference value and the preset phase difference threshold is determined, and the cycle jump number of the first frequency point where a large cycle jump occurs is determined based on the relationship between the two.

[0040] This application embodiment constructs a physical constraint-based fast prediction mechanism for large cycle slips by comparing the consistency of Doppler integral phase and carrier phase changes. It can complete the screening of all frequency points within milliseconds and roughly estimate the number of large cycle slip integers for subsequent temporary corrections, thereby significantly reducing the computational burden of subsequent fine detection and providing a reliable guarantee for the real-time performance of low-Earth orbit / medium-Earth orbit fusion navigation satellites.

[0041] Furthermore, step S114 in this embodiment may include the following steps: Step S114a: If the phase difference value is greater than the preset phase difference value threshold, determine the first frequency point where a large cycle jump occurs among all frequency points; Step S114b: Determine the number of cycle jumps at the first frequency point based on the phase difference value.

[0042] In steps S114a-S114b of this embodiment, for each frequency point, the frequency point corresponding to the condition where the phase difference value is greater than a preset phase difference value threshold is determined as the first frequency point where a large cycle slip occurs. The cycle slip number of the first frequency point is determined by the phase difference value. In one example, the phase difference value can be directly used as the cycle slip number of the first frequency point, or the phase difference value can be rounded to the nearest integer as the cycle slip number of the first frequency point for calculation.

[0043] Furthermore, embodiments of this application may also include the following steps: Step S210: Obtain the epoch interval and initial difference threshold; Step S220: Determine the preset phase difference threshold based on the Doppler frequency offset, epoch interval, and initial difference threshold of the target satellite at the current epoch.

[0044] In step S210, the epoch interval represents the time difference between two adjacent sampling times of the receiver, and the initial difference threshold is the basic noise threshold. In one example, the epoch interval can be 0.1 to 1.0 seconds, and the initial difference threshold can be 0.5 cycles.

[0045] In step S220, a preset phase difference threshold is determined using the Doppler frequency offset of the target satellite at the current epoch, the epoch interval, and the initial difference threshold. The preset phase difference threshold is determined using the following formula:

[0046] In the formula, This indicates the preset phase difference threshold. Indicates the initial difference threshold. This represents the Doppler scaling factor.

[0047] Low Earth orbit (LEO) satellites travel at extremely high speeds, approximately 7-8 km / s, and their Doppler frequency offset can reach ±50 kHz, dozens of times greater than that of medium Earth orbit (MEO) satellites. These dramatic frequency variations make signal tracking difficult, and cycle slips are frequent and large in amplitude. Traditional methods using fixed thresholds to determine the presence of cycle slips often result in numerous false alarms due to high dynamic noise. This application's embodiment employs a threshold that adaptively adjusts with the Doppler frequency offset, effectively avoiding misjudgments in high-dynamic scenarios. Specifically, when the LEO satellite's Doppler frequency offset is large, the preset phase difference threshold automatically widens to prevent normal dynamic changes from being misinterpreted as cycle slips; conversely, when the MEO satellite's Doppler frequency offset is small, the preset phase difference threshold automatically tightens to maintain high-sensitivity detection. This allows this application's embodiment to simultaneously adapt to the high dynamic characteristics of LEO satellites and the low dynamic characteristics of MEO satellites.

[0048] Furthermore, step S130 in this embodiment may include the following steps: Step S131: Obtain the ionospheric delay value and carrier phase prediction value for the current epoch, wherein the carrier phase prediction value is predicted by the carrier phase prediction model; Step S132: Construct a generalized geometrically independent test quantity based on the first carrier phase correction value and the ionospheric delay value; Step S133: Based on the first carrier phase correction value and the carrier phase prediction value, construct a multi-frequency adaptive weighted test quantity; Step S134: Based on the generalized geometrically independent test quantity, the multi-frequency adaptive weighted test quantity, and the preset test quantity range, determine the second frequency point where the small cycle slip occurs among all frequency points; Step S135: Construct a small cycle slip estimation model based on the second frequency point; Step S136: Perform an integer search based on the small cycle slip estimation model to obtain the cycle slip number of the second frequency point.

[0049] In step S131, ionospheric delay is the observation error caused by changes in propagation speed and path when electromagnetic waves pass through the Earth's ionosphere, which can significantly affect the accuracy of satellite navigation and positioning. The carrier phase prediction value refers to the theoretically expected value of the carrier phase at the current epoch, predicted and extrapolated using historical observation data through a carrier phase prediction model. For example, the carrier phase prediction model can be a first-order differential autoregressive model (ARIMA, Autoregressive Integrated Moving Average), specifically, an ARIMA(1, 1, 0) model, i.e., first-order autoregressive, first-order differential, and zero-order moving average. If the target satellite has a continuous historical observation segment without cycle slips for 5 epochs or more, the mean of the geometrically independent combination within the sliding window is used as the ionospheric delay value, which is determined by the following formula:

[0050] In the formula, This represents the ionospheric delay value at the current epoch. Indicates the length of the sliding window. This represents the index number of the epoch within the sliding window. Indicates the index of the current epoch. This represents the carrier wavelength at the i-th frequency point. This indicates that the j-th frequency point is in the epoch. carrier phase, This represents the carrier wavelength at the j-th frequency point. This indicates that the j-th frequency point is in the epoch. The carrier phase. In one example, the length of the sliding window can be 20 epochs. If the target satellite does not have a continuous historical observation segment of 5 epochs or more without cycle slips, the ionospheric delay value is calculated using the Klobuchar (Klobuchar Ionospheric) model for medium-Earth orbit satellites and the IRI (International Reference Ionosphere) model for low-Earth orbit satellites.

[0051] In step S132, the GF (Geometry-Free) test metric is constructed using the first carrier phase correction value and ionospheric delay value at any two frequency points. Taking the current epoch as an example, the GF test metric for the current epoch is constructed using the following formula:

[0052]

[0053] In the formula, This represents the generalized geometric independence test for the current epoch. This represents the phase correction value of the first carrier at the i-th frequency point in the current epoch. This represents the phase correction value of the first carrier at the j-th frequency point in the current epoch. Indicates the ionospheric proportionality coefficient. This represents the ionospheric delay value at the current epoch; Taking the previous epoch as an example, the generalized geometrical independence test for the previous epoch is constructed using the following formula:

[0054] In the formula, This represents the generalized geometrical independence test quantifier for the previous epoch. This represents the phase correction value of the first carrier at the i-th frequency point in the previous epoch. This represents the phase correction value of the first carrier at the j-th frequency point in the previous epoch. This represents the ionospheric delay value of the previous epoch.

[0055] In step S133, the verification value for each frequency point is calculated using the first carrier phase correction value and the carrier phase prediction value corresponding to each frequency point, thereby obtaining the multi-frequency adaptive weighted verification value. The multi-frequency adaptive weighted verification value is constructed using the following formula:

[0056]

[0057]

[0058] In the formula, This represents the test value at the i-th frequency point. This represents the carrier phase prediction value at the i-th frequency point. This represents the multi-frequency adaptive weighted test metric. This represents the i-th frequency point. Indicates the total number of frequency points. Indicates weight, This represents the carrier-to-noise ratio (CNR) of the i-th frequency point in the current epoch. This represents the variance of the test result at the i-th frequency point within the sliding window. This represents the j-th frequency point. This represents the carrier-to-noise ratio at the j-th frequency point in the current epoch.

[0059] In step S134, the second frequency point experiencing a small cycle slip can be determined from all frequency points using the generalized geometric independence checksum, the multi-frequency adaptive weighted checksum, and the preset checksum range. The preset checksum includes a first preset checksum range and a second preset checksum range. Specifically, for all frequency points, the difference between the generalized geometric independence checksum of the current epoch and the generalized geometric independence checksum of the previous epoch is used as the checksum difference; if the checksum difference is not within the first preset checksum range, the frequency point corresponding to the checksum difference not being within the first preset checksum range is determined as the second frequency point experiencing a small cycle slip. In one example, the first preset checksum range includes... ,in, This represents the mean of the differences in check values ​​within the sliding window. This represents the standard deviation of the difference in check values ​​within the sliding window. For all frequency points, if the multi-frequency adaptive weighted check value is not within the range of the second preset check value, the frequency point corresponding to this non-preset check value range is determined as the second frequency point where the small cycle slip occurs. In one example, the range of the second preset check value includes... ,in, This represents the mean of the multi-frequency adaptive weighted test within the sliding window. This represents the standard deviation of the multi-frequency adaptive weighted test within the sliding window.

[0060] In step S135, a small cycle slip estimation model is constructed based on at least two frequency points in the second frequency points determined in step S134 that exhibit small cycle slips. As an example, the small cycle slip estimation model constructed for two frequency points in the second frequency points includes:

[0061] In the formula, This indicates the carrier wavelength of frequency point 1. This represents the carrier phase epoch difference at frequency point 1. This indicates the carrier wavelength at frequency point 2. This represents the carrier phase epoch difference at frequency point 2. This represents the cycle jump number of the minor cycle jump at frequency point 1. This represents the cycle jump number of the minor cycle jump at frequency point 2. This represents the change in ionospheric delay between adjacent epochs. This indicates the carrier phase of frequency point 1 in the current epoch. This represents the carrier phase prediction value for frequency point 1. This represents the observation noise and model error at frequency point 1. Furthermore, embodiments of this application can also construct small cycle slip estimation models for multiple frequency points within the second frequency range. The small cycle slip estimation models constructed in the multi-frequency case have higher accuracy and stronger reliability.

[0062] In step S136, the cycle slip number of the small cycle slip at frequency point 1 is... Week slips of frequency point 2 As an unknown integer, a search is conducted within a range of ±5 weeks to find the integer pair that minimizes the residual of the small cycle slip estimation model. This integer pair is then used to determine the cycle slip number at the second frequency point. Furthermore, when constructing the small cycle slip estimation model using multiple frequency points, a least-squares fuzzy search is employed to perform integer estimation to determine the cycle slip number at the second frequency point.

[0063] In the embodiments of this application, steps S131 to S136 obtain ionospheric delay values ​​and carrier phase prediction values, construct a generalized geometrically independent check quantity and a multi-frequency adaptive weighted check quantity respectively, and determine the second frequency point where a small cycle slip occurs among all frequency points based on the preset check quantity range. Then, a small cycle slip estimation model is constructed for the second frequency point and integer search is performed to solve it. Thus, based on the coarse detection of large cycle slips in step S110, the accurate identification of small cycle slips and the accurate estimation of cycle slip values ​​are further realized, which effectively improves the detection capability and repair accuracy of weak cycle slips in high dynamic scenarios of low-orbit / medium-orbit satellite fusion.

[0064] Furthermore, step S140 in this embodiment may include the following steps: Step S141: Based on the sum of the cycle slip counts at the first frequency point and the second frequency point, obtain the cycle slip sum; Step S142: Determine the second carrier phase correction value based on the difference between the carrier phase and the cycle slip sum of the first frequency point in the current epoch.

[0065] In step S141, the cycle slip sum is determined by the following formula:

[0066] In the formula, Indicates the sum of cycle jumps, This represents the number of cycle slips at the first frequency point. This indicates the number of cycle jumps at the second frequency point.

[0067] In step S142, the difference between the carrier phase and the cycle slip sum of the first frequency point in the current epoch is used as the second carrier phase correction value.

[0068] Furthermore, step S150 in this embodiment may include the following steps: Step S151: Determine the first distance between the satellite and the receiver based on the satellite motion state information and the receiver motion state information; Step S152: Take the change value of the first distance from the previous epoch to the current epoch as the first distance change value; Step S153: Based on the second carrier phase correction value and the carrier phase of the previous epoch, determine the second distance change value between the satellite and the receiver; Step S154: Based on the difference between the first distance change value and the second distance change value, obtain the distance change difference value; Step S155: If the distance change difference is less than the preset distance threshold, the second carrier phase correction value is determined as the target carrier phase.

[0069] In steps S151-S152, the first distance change value is determined by the following formula:

[0070] In the formula, This represents the first distance change value. This indicates the satellite's motion status information at the current epoch. This indicates the receiver motion state information for the current epoch. This indicates the satellite's motion status information in the previous epoch. This indicates the receiver motion state information of the previous epoch.

[0071] In step S153, the second distance change value is determined by the following formula:

[0072] In the formula, This represents the second distance change value. Indicates the carrier wavelength at the current frequency. This represents the second carrier phase correction value. This indicates the carrier phase of the previous epoch.

[0073] In step S154, the distance change difference is determined by the following formula:

[0074] In the formula, This represents the difference in distance. This represents the first distance change value. This represents the second distance change value.

[0075] In step S155, the preset distance threshold includes a first preset distance threshold and a second preset distance threshold. For low-Earth orbit (LEO) satellites, the high orbital velocity causes drastic geometric changes. If the distance change difference for a preset number of consecutive epochs is less than the first preset distance threshold, the second carrier phase correction value is determined as the target carrier phase. In one example, the preset number of consecutive epochs can be 3 consecutive epochs, and the first preset distance threshold can be... For medium-Earth orbit satellites, due to their relatively gentle geometric changes, the condition is relaxed to determine the second carrier phase correction value as the target carrier phase if the distance change difference is less than a second preset distance threshold. In one example, the second preset distance threshold could be... Furthermore, if the aforementioned conditions are not met, the carrier phase correction is marked as failed, the target satellite is set to unavailable at all frequencies in the current epoch, the sliding window is cleared, and the ambiguity re-initialization process is triggered.

[0076] Steps S151-S155 of this application embodiment fully utilize the unique advantage of the drastic geometric changes of low-orbit satellites, providing a strong guarantee for the reliability of carrier phase repair results.

[0077] This application also provides an electronic device, including: The memory is configured to store instructions; The processor is configured to retrieve instructions from memory and, when executing instructions, to implement a cycle slip correction method based on the carrier phase as described above.

[0078] Figure 2 A schematic diagram of an electronic device according to an embodiment of this application is shown, such as... Figure 2 As shown, the electronic device provided in this application embodiment may include a processor 201 and a memory 202. It should be understood that this application does not limit the number of processors and memories in the network device.

[0079] Processor 201 may include any one or more processors such as a central processing unit (CPU), a graphics processing unit (GPU), a microprocessor (MP), or a digital signal processor (DSP).

[0080] Memory 202 may include volatile memory, such as random access memory (RAM). Processor 201 may also include non-volatile memory, such as read-only memory (ROM), flash memory, hard disk drive (HDD), or solid state drive (SSD).

[0081] The memory 202 stores executable program code, which the processor 201 executes to implement the functions of the aforementioned method embodiments. That is, the memory 202 stores instructions for executing the aforementioned carrier phase cycle slip correction method.

[0082] It is understood that the electronic device provided in this application embodiment can implement each process of the carrier phase cycle slip correction method in the above embodiment and achieve the same technical effect. To avoid repetition, it will not be described again here.

[0083] This application also provides a machine-readable storage medium storing instructions for causing a machine to perform a cycle slip correction method based on the carrier phase as described above.

[0084] It is understood that the machine-readable storage medium provided in the embodiments of this application can implement each process of the carrier phase cycle slip correction method in the above embodiments and achieve the same technical effect. To avoid repetition, it will not be described again here.

[0085] This application also provides a computer program product, which includes a computer program that, when executed by a processor, implements a cycle slip correction method based on the carrier phase as described above.

[0086] It is understood that the computer program product provided in this application embodiment can implement each process of the carrier phase cycle slip correction method in the above embodiment and achieve the same technical effect. To avoid repetition, it will not be described again here.

[0087] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0088] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0089] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0090] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0091] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0092] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0093] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0094] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0095] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for correcting cycle slip of carrier phase, characterized in that, The cycle slip correction method includes: For all frequency points of the target satellite, based on the Doppler frequency offset of each frequency point in the current epoch, the Doppler frequency offset of the previous epoch, the carrier phase of the current epoch, and the carrier phase of the previous epoch, the cycle slip number of the first frequency point with a large cycle slip among all the frequency points is determined, wherein the target satellite includes low-Earth orbit satellites and / or medium-Earth orbit satellites. Based on the cycle slip number of the first frequency point, the carrier phase of the first frequency point in the current epoch is corrected to obtain the first carrier phase correction value of the current epoch. Based on the first carrier phase correction value, a small cycle slip estimation model is constructed to determine the number of cycle slips at the second frequency point where small cycle slips occur among all the frequency points; Based on the cycle slip count of the first frequency point and the cycle slip count of the second frequency point, the carrier phase of the first frequency point in the current epoch is corrected to obtain the second carrier phase correction value; The target carrier phase is determined based on the satellite motion state information of the target satellite, the receiver motion state information of the receiver, and the second carrier phase correction value.

2. The method according to claim 1, characterized in that, The step of determining the cycle slip number of the first frequency point experiencing a large cycle slip among all the frequency points based on the Doppler frequency offset of each frequency point in the current epoch, the Doppler frequency offset of the previous epoch, the carrier phase of the current epoch, and the carrier phase of the previous epoch includes: Based on the Doppler frequency offset of the frequency point in the current epoch and the Doppler frequency offset of the previous epoch, the Doppler frequency offset integral phase is obtained. Based on the carrier phase of the current epoch and the carrier phase of the previous epoch, the carrier phase change is obtained; Based on the Doppler frequency offset integral phase and the carrier phase change, the phase difference between the Doppler frequency offset integral phase and the carrier phase change is obtained; Based on the phase difference value and the preset phase difference value threshold, determine the cycle slip number of the first frequency point where the large cycle slip occurs among all the frequency points.

3. The method according to claim 2, characterized in that, The step of determining the cycle slip number of the first frequency point where the large cycle slip occurs among all the frequency points based on the phase difference value and a preset phase difference threshold includes: If the phase difference value is greater than the preset phase difference value threshold, determine the first frequency point where the large cycle jump occurs among all the frequency points; The cycle jump number at the first frequency point is determined based on the phase difference value.

4. The method according to claim 2, characterized in that, The cycle slip correction method further includes: Obtain the epoch interval and initial difference threshold; The preset phase difference threshold is determined based on the Doppler frequency offset of the target satellite at the current epoch, the epoch interval, and the initial difference threshold.

5. The method according to claim 1, characterized in that, The step of constructing a small cycle slip estimation model based on the first carrier phase correction value to determine the cycle slip number of the second frequency point where a small cycle slip occurs among all the frequency points includes: Obtain the ionospheric delay value and carrier phase prediction value for the current epoch, wherein the carrier phase prediction value is predicted by a carrier phase prediction model; Based on the first carrier phase correction value and the ionospheric delay value, a generalized geometrically independent test quantity is constructed; Based on the first carrier phase correction value and the carrier phase prediction value, a multi-frequency adaptive weighted test quantity is constructed; Based on the generalized geometrically independent test value, the multi-frequency adaptive weighted test value, and the preset test value range, the second frequency point where a small cycle slip occurs among all the frequency points is determined. Based on the second frequency point, the small cycle slip estimation model is constructed; Based on the small cycle slip estimation model, an integer search is performed to obtain the cycle slip number of the second frequency point.

6. The method according to claim 1, characterized in that, The step of correcting the carrier phase of the first frequency point in the current epoch based on the cycle slip count of the first frequency point and the cycle slip count of the second frequency point to obtain the second carrier phase correction value includes: The sum of cycle slips at the first frequency point and the second frequency point is used to obtain the cycle slip sum. The second carrier phase correction value is determined based on the difference between the carrier phase of the first frequency point at the current epoch and the cycle slip sum value.

7. The method according to claim 1, characterized in that, Determining the target carrier phase based on the satellite motion state information of the target satellite, the receiver motion state information of the receiver, and the second carrier phase correction value includes: Based on the satellite motion state information and the receiver motion state information, a first distance between the satellite and the receiver is determined; The change value of the first distance from the previous epoch to the current epoch is taken as the first distance change value; Based on the second carrier phase correction value and the carrier phase of the previous epoch, a second distance change value between the satellite and the receiver is determined; The distance change difference is obtained based on the difference between the first distance change value and the second distance change value; If the distance change difference is less than a preset distance threshold, the second carrier phase correction value is determined as the target carrier phase.

8. An electronic device, characterized in that, include: The memory is configured to store instructions; The processor is configured to retrieve the instructions from the memory and, when executing the instructions, to implement the cycle slip correction method for the carrier phase according to any one of claims 1 to 7.

9. A machine-readable storage medium, characterized in that, The machine-readable storage medium stores instructions for causing the machine to perform the cycle slip correction method for the carrier phase according to any one of claims 1 to 7.

10. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements the cycle slip correction method for the carrier phase according to any one of claims 1 to 7.

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