Phase difference data processing method and system based on dual-polarized GNSS occultation

Abstract

The application provides a phase difference data processing method and system based on dual-polarized GNSS occultation, comprising: obtaining a low-orbit satellite orbit through precise orbit determination of LEO observation data and positioning auxiliary data; calculating atmospheric additional phase data of H channel and V channel based on the low-orbit satellite orbit and time-registered phase data, and performing geometric co-registration to determine the space-time position of the occultation event; constructing polarized phase difference according to the geometric co-registered phase data to obtain phase difference data, and repairing phase difference cycle slip according to the phase difference data; and performing data processing on the cycle slip repaired differential phase sequence to output phase difference products. The application can suppress clock and geometric residual, eliminate phase breaks caused by half / integer cycle slip and open / closed loop conversion, and correct phase difference, thereby outputting stable and consistent differential phase observable.

Description

Technical Field

[0001] This application belongs to the field of occultation detection technology, and in particular relates to a phase difference data processing method and system based on dual-polarized GNSS occultation. Background Technology

[0002] Global Navigation Satellite System (GNSS) occultation (RO) technology is renowned for its all-weather, global coverage, and high vertical resolution, and has been widely used for the inversion of atmospheric physical parameters. However, traditional occultation (RO) only acquires scalar refractive index information, making it difficult to directly perceive the microphysical processes of cloud precipitation. Polarized occultation (PRO) introduces horizontal (H) and vertical (V) dual-polarized channels at the low-Earth orbit satellite receiver, acquires the atmospheric additional phase of the H and V channels, and constructs their differential phase ΔΦ, thus becoming sensitive to the electromagnetic anisotropy response caused by non-spherical and directional hydrophobic condensates. Existing spaceborne experiments have shown that the differential phase should remain constant in a non-polarized medium path, while a significant peak appears in the differential phase when the radio wave path passes over a precipitation layer, with the amplitude related to the average precipitation intensity along the path.

[0003] Current methods for systematically handling phase differences mainly suffer from the following problems:

[0004] First, there is the phase discontinuity problem caused by the time / frequency inconsistency of the dual-channel I / Q streams; second, there is the problem that receiver clock bias, hardware delay, cycle slip and other residuals are exposed and amplified in the differential; third, operational processing requires unified smoothing, detrending, calibration and quality control standards to achieve consistency across satellites, constellations and time.

[0005] Therefore, it is urgent to propose a business-oriented, end-to-end dual-polarization occultation differential phase construction and calibration method to establish a robust quality control and error suppression link. Summary of the Invention

[0006] In view of this, this application aims to propose a phase difference data processing method and system based on dual-polarized GNSS occultation to solve at least one of the above-mentioned problems.

[0007] To achieve the above objectives, the technical solution of this application is implemented as follows:

[0008] In a first aspect, this application provides a method for processing phase difference data based on dual-polarized GNSS occultation, including:

[0009] The low-Earth orbit satellite orbit is obtained by precise orbit determination using LEO observation data and positioning auxiliary data;

[0010] Based on the low-Earth orbit satellite orbit and time-registered phase data, atmospheric additional phase data for the H and V channels are calculated and geometrically co-registered to determine the spatiotemporal location of the occultation event; wherein, the time-registered phase data is obtained based on the I / Q data synchronization and phase reconstruction of the H and V channels;

[0011] Polarization phase difference is constructed based on the phase data after geometric co-registration to obtain phase difference data, and phase difference cycle slip repair is performed based on the phase difference data;

[0012] The differential phase sequence after cycle slip repair is processed to output a phase difference product; wherein, the data processing includes normalization processing, phase difference smoothing processing, and removal of linear trends.

[0013] Secondly, based on the same inventive concept, this application also provides a phase difference data processing system based on dual-polarized GNSS occultation, comprising:

[0014] The precision orbit determination module is configured to obtain the low Earth orbit satellite orbit by performing precise orbit determination on LEO observation data and positioning assistance data;

[0015] The geometric co-registration module is configured to calculate atmospheric additional phase data for the H and V channels based on the low-Earth orbit satellite orbit and time-registered phase data, and perform geometric co-registration to determine the spatiotemporal location of the occultation event; wherein the time-registered phase data is obtained based on the I / Q data synchronization and phase reconstruction of the H and V channels;

[0016] The cycle slip repair module is configured to construct a polarization phase difference based on the phase data after geometric co-registration to obtain phase difference data, and to perform phase difference cycle slip repair based on the phase difference data.

[0017] The data processing module is configured to process the differential phase sequence after cycle slip repair to output a phase difference product; wherein the data processing includes normalization processing, phase difference smoothing processing, and removal of linear trends.

[0018] Thirdly, based on the same inventive concept, this application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method described in the first aspect.

[0019] Fourthly, based on the same inventive concept, this application also provides a non-transitory computer-readable storage medium, wherein the non-transitory computer-readable storage medium stores computer instructions for causing the computer to perform the method as described in the first aspect.

[0020] Compared with existing technologies, the phase difference data processing method and system based on dual-polarized GNSS occultation described in this application have the following advantages:

[0021] The phase difference data processing method based on dual-polarization GNSS occultation described in this application takes "H / V polarization phase synchronization - differential phase construction cycle slip repair - smoothing detrending - phase difference product" as the main line. The system suppresses clock and geometric residuals, eliminates phase breaks caused by half / integers and open / closed loop transitions, corrects phase differences, and outputs stable and consistent differential phase observables, thereby forming an operational product suitable for precipitation analysis. Attached Figure Description

[0022] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0023] Figure 1 This is a schematic diagram of the polarization occultation principle described in the embodiments of this application;

[0024] Figure 2 This is a flowchart of a phase difference data processing method based on dual-polarized GNSS occultation, as described in an embodiment of this application.

[0025] Figure 3 This is a flowchart illustrating the occultation tangent point height as described in the embodiments of this application;

[0026] Figure 4 This is a schematic diagram of the phase difference data processing system based on dual-polarized GNSS occultation as described in an embodiment of this application;

[0027] Figure 5 This is a schematic diagram of the hardware structure of the electronic device described in an embodiment of this application. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0029] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0030] Polarized occultation is a modification of occultation in terms of hardware and processing links, further expanding the observation and application of occultation. The observation link is similar to that of occultation, utilizing the refraction characteristics of GNSS signals propagating across the ground to accurately track signal phase and Doppler variations, and invert atmospheric meteorological parameter profiles. The principle diagram is shown below. Figure 1 As shown. This application proposes a complete polarization differential phase data processing method for dual-polarization GNSS occultation observations, namely an end-to-end processing link from the I / Q data of the H / V channels to the polarization master observation ΔΦ. The entire method is designed strictly around polarization occultation data processing.

[0031] The core of polarimetric occultation technology lies in the different phase delays that occur when the GNSS signals received by the H and V channels traverse the troposphere containing precipitation particles. This difference primarily stems from the varying polarization responses of non-spherical precipitation particles (such as raindrops, ice crystals, and graupel) to electromagnetic waves. As electromagnetic waves pass through these particles with specific orientations and shapes, the horizontal and vertical polarization components experience different propagation paths and phase changes, resulting in an observable phase difference at the receiver. This application is based on this physical principle, achieving effective detection of the precipitation layer by precisely measuring and processing this phase difference.

[0032] The embodiments of this application are described in detail below with reference to the accompanying drawings.

[0033] Please see Figure 2 As shown, this embodiment provides a phase difference data processing method based on dual-polarized GNSS occultation, specifically including the following steps:

[0034] Step S101: Obtain the low Earth orbit satellite orbit by performing precise orbit determination on LEO observation data and positioning auxiliary data.

[0035] Specifically, in this embodiment, by combining LEO observation data and positioning assistance data from the original observation data, precise orbit determination of the polarimetric occultation satellite is performed to obtain a more accurate low-Earth orbit satellite orbit.

[0036] Step S102: Calculate the atmospheric additional phase data of H channel and V channel based on the low-orbit satellite orbit and time-registered phase data, and perform geometric co-registration to determine the spatiotemporal location of the occultation event; wherein, the time-registered phase data is obtained based on the synchronization and phase reconstruction of the dual-polarized occultation data of H channel and V channel.

[0037] Specifically, in this embodiment, in a dual-polarized occultation system, the I / Q data of the H and V channels must maintain strict time synchronization and frequency consistency, which is the basis for subsequent differential phase calculations. Due to the significant Doppler frequency shift during the occultation process, the sampling clocks of the two channels may have slight differences. At the same time, inconsistencies in the receiver hardware will also cause systematic deviations in amplitude and phase between the two signals. Therefore, it is necessary to eliminate these non-physical systematic errors and ensure that the two signals are perfectly aligned in time, frequency, and amplitude. The calculation is shown in Equation (1), which uses a cross-correlation function to find the optimal time delay alignment between the H and V channel signals.

[0038] (1)

[0039] In the formula, This represents the complex baseband signal of channel H; This represents the complex baseband signal of channel V; I and Q represent the in-phase and quadrature components, respectively; j is the imaginary unit. For the first The timestamp of each sampling moment; For the V channel at time The complex conjugate of the complex baseband signal; τ is the time delay search range; Typically, the sampling interval is ±1. This indicates the search for the value of τ that maximizes the cross-correlation function.

[0040] Both the H and V channels receive I / Q complex baseband signals separately. In order to eliminate the phase jump caused by the small displacement of the target and the change of atmospheric refractive index, it is necessary to extract accurate phase information from the H and V channels respectively, and calculate as shown in formula (2).

[0041] (2)

[0042] In the formula, for Phase value after untangling at time step, unit: rad; This is the phase unwrapping function, used to eliminate 2π phase jumps.

[0043] The H / V polarization phase obtained by phase reconstruction has consistency across satellites, constellations, and time periods, which enables the establishment of a unified data processing link and quality control standard for different GNSS systems at different times for different polarization occultation satellites.

[0044] The orbit of a low-Earth orbit satellite needs to be precisely determined using LEO observation data and positioning aid data. The atmospheric additional phase data of the H and V channels are calculated using the low-Earth orbit satellite orbit and the phase data after time registration. Then, geometric registration is performed. The purpose of geometric co-registration is to establish a strict one-to-one correspondence between the differential phase at each sampling time and the geometric position of the corresponding occultation tangent point.

[0045] In occultation geometry, a GNSS signal originates from the transmitting satellite, passes through the atmosphere, and reaches the LEO receiver. The point of tangency between the signal path and the Earth's surface is called the occultation tangent point. The position and altitude of this point directly determine the atmospheric structure the signal passes through; therefore, the tangent point position must be accurately calculated for each sampling moment. Both the LEO orbit and GNSS position require Lagrange interpolation calculations, and signal propagation delay needs to be corrected. The flowchart is as follows: Figure 3 As shown.

[0046] The formula for the height of the occultation tangent point is shown in (3).

[0047] (3)

[0048] In the formula, for The unit line-of-sight vector at any given time (dimensionless). for Position vector of GNSS satellite at any given time, in meters; for Position vector of the LEO receiver at time moment, in meters; The tangent parameter represents the distance from the LEO receiver position along the line of sight to the tangent point, in meters. for The position vector of the tangent point at time moment represents the position of the point of tangency between the signal path and the Earth's surface in the geocentric-geofixed coordinate system; for The height of the tangent point at any given moment; The modulus at the tangent point is the line-of-sight height of the GNSS navigation satellite relative to the LEO. The radius is the Earth's radius.

[0049] Step S103: Construct polarization phase difference based on the phase data after geometric co-registration to obtain phase difference data, and perform phase difference cycle slip repair based on the phase difference data.

[0050] Specifically, in this embodiment, after obtaining the phase data of the H and V channels after phase reconstruction calibration, it is necessary to construct the polarization phase difference to obtain the phase difference data, as shown in formula (4).

[0051] (4)

[0052] In the formula, and Representing channels H and V respectively The phase of a moment.

[0053] Even after the phase is reconstructed in the H and V channels, cycle slips will still exist in the phase difference after the phase difference is constructed. Therefore, it is necessary to detect and repair cycle slips in the phase difference. Half-cycle slips are corrected during the closed loop and full-cycle slips are corrected during the open loop, as shown in Equation (5).

[0054] (5)

[0055] Step S104: The differential phase sequence after cycle slip repair is processed to output a phase difference product; wherein, the data processing includes normalization processing, phase difference smoothing processing and removal of linear trends.

[0056] Specifically, in this embodiment, the differential phase after cycle slip repair ideally only reflects the polarization difference caused by water condensate in the atmosphere. However, in the actual system, it also includes constant bias and linear bias. The constant bias is mainly caused by hardware inconsistencies. Based on the fact that there is no water vapor in the atmosphere at an altitude of 30-50km, there is almost no influence of water condensate in this region. The differential phase is mainly caused by hardware differences. The constant phase is calculated by the least squares estimation method using the signal-to-noise ratio, as shown in formula (6).

[0057] (6)

[0058] In the formula, The constant bias obtained is expressed in rad; c is the bias search value in radians. for The weighting coefficient for each moment (dimensionless); H is taken as the index range of tangent point height in the range of 30-40km; This indicates the search for the value of c that minimizes the objective function; and for Signal-to-noise ratio of channels H and V at time points; To remove the constant bias from the differential phase, the weighting coefficients are proportional to the product of the signal-to-noise ratios (SNRs) of the two channels, ensuring that high SNR data has a greater impact on bias estimation. After this step, the zero reference of the differential phase sequence is unified, and all data represent phase differences relative to an altitude of 30-40 km.

[0059] The linear bias present in actual differential phase is mainly caused by ionospheric effects. When a signal passes through the ionosphere, electromagnetic effects cause the phase difference to tend to shift in a certain direction. Therefore, it is necessary to eliminate this potential trend term above 20km. This embodiment uses moving average filtering to suppress high-frequency noise and linear detrending to eliminate low-frequency drift, outputting a smooth differential phase sequence suitable for precipitation analysis while preserving the physical characteristics of the signal.

[0060] The differential phase sequence is smoothed by a 1-second window as shown in formula (7).

[0061] (7)

[0062] In the formula, for Phase difference after time smoothing; For window length, Dimensionless Sampling rate, unit: Hz; For the first in the window This filter effectively suppresses high-frequency noise while preserving the physical characteristics of the signal.

[0063] Using phase difference data at tangent heights above 20km, the linear trend of the differential phase sequence is fitted using least squares, and the linear trend is removed from the smoothed phase difference, as shown in formula (8).

[0064] (8)

[0065] In the formula, The slope of the fitted line, in rad / m; The intercept of the fitted line, in rad; The height of the occultation tangent point, in meters (m). This is the phase difference after removing the linear trend, which is the final phase difference used.

[0066] It is important to note that This represents the phase difference as a function of time. The phase difference is a function of the tangent point height. .

[0067] The method described in this embodiment is based on the main line of "H / V polarization phase synchronization - differential phase construction cycle slip repair - smoothing detrending - phase difference product". The system suppresses clock and geometric residuals, eliminates phase breaks caused by half / full cycle slips and open / closed loop conversion, corrects phase differences, and outputs stable and consistent differential phase observables, thereby forming an operational product suitable for precipitation analysis.

[0068] It should be noted that the above description describes some embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in a different order than that shown in the above embodiments and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0069] Based on the same inventive concept, and corresponding to the methods of any of the above embodiments, the embodiments of this application also provide a phase difference data processing system based on dual-polarized GNSS occultation.

[0070] like Figure 4 As shown, the phase difference data processing system based on dual-polarized GNSS occultation includes:

[0071] The precise orbit determination module 11 is configured to obtain the low Earth orbit satellite orbit by performing precise orbit determination on LEO observation data and positioning assistance data;

[0072] The geometric co-registration module 12 is configured to calculate atmospheric additional phase data for the H and V channels based on the low-Earth orbit satellite orbit and time-registered phase data, and perform geometric co-registration to determine the spatiotemporal location of the occultation event; wherein the time-registered phase data is obtained based on the synchronization and phase reconstruction of dual-polarized occultation data for the H and V channels;

[0073] The cycle slip repair module 13 is configured to construct a polarization phase difference based on the phase data after geometric co-registration to obtain phase difference data, and perform phase difference cycle slip repair based on the phase difference data.

[0074] The data processing module 14 is configured to process the differential phase sequence after cycle slip repair to output a phase difference product; wherein the data processing includes normalization processing, phase difference smoothing processing, and removal of linear trends.

[0075] For ease of description, the above system is described by dividing it into various modules based on their functions. Of course, in implementing the embodiments of this application, the functions of each module can be implemented in one or more software and / or hardware.

[0076] The system described in the above embodiments is used to implement the corresponding method in any of the foregoing embodiments and has the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0077] Based on the same inventive concept, corresponding to the methods of any of the above embodiments, embodiments of this application also provide an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the methods described in any of the above embodiments.

[0078] Figure 5 This embodiment illustrates a more specific hardware structure of an electronic device, which may include a processor 1010, a memory 1020, an input / output interface 1030, a communication interface 1040, and a bus 1050. The processor 1010, memory 1020, input / output interface 1030, and communication interface 1040 are interconnected internally via the bus 1050.

[0079] The processor 1010 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this specification.

[0080] The memory 1020 can be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory), static storage device, dynamic storage device, etc. The memory 1020 can store the operating system and other applications. When the technical solutions provided in the embodiments of this specification are implemented by software or firmware, the relevant program code is stored in the memory 1020 and is called and executed by the processor 1010.

[0081] The input / output interface 1030 is used to connect input / output modules to realize information input and output. The input / output modules can be configured as components in the device (not shown in the figure) or externally connected to the device to provide corresponding functions. Input devices may include keyboards, mice, touch screens, microphones, various sensors, etc., and output devices may include displays, speakers, vibrators, indicator lights, etc.

[0082] The communication interface 1040 is used to connect a communication module (not shown in the figure) to enable communication between this device and other devices. The communication module can communicate via wired means (such as USB, Ethernet cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0083] Bus 1050 includes a pathway for transmitting information between various components of the device, such as processor 1010, memory 1020, input / output interface 1030, and communication interface 1040.

[0084] It should be noted that although the above-described device only shows the processor 1010, memory 1020, input / output interface 1030, communication interface 1040, and bus 1050, in specific implementations, the device may also include other components necessary for normal operation. Furthermore, those skilled in the art will understand that the above-described device may only include the components necessary for implementing the embodiments of this specification, and not necessarily all the components shown in the figures.

[0085] The electronic devices described above are used to implement the corresponding methods in any of the foregoing embodiments and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0086] Based on the same inventive concept, corresponding to the methods of any of the above embodiments, this application also provides a non-transitory computer-readable storage medium that stores computer instructions for causing the computer to perform the methods described in any of the above embodiments.

[0087] The computer-readable medium of this embodiment includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information can be computer-readable instructions, data structures, program modules, 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, magnetic disk storage or other magnetic storage devices, or any other non-transfer medium that can be used to store information accessible by a computing device.

[0088] The computer instructions stored in the storage medium of the above embodiments are used to cause the computer to perform the methods described in any of the above embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0089] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application (including the claims) is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this application as described above, which are not provided in the details for the sake of brevity.

[0090] Additionally, to simplify the description and discussion, and to avoid obscuring the embodiments of this application, the well-known power / ground connections to integrated circuit (IC) chips and other components may or may not be shown in the provided drawings. Furthermore, the apparatus may be shown in block diagram form to avoid obscuring the embodiments of this application, and this also takes into account the fact that the details of the implementation of these block diagram apparatuses are highly dependent on the platform on which the embodiments of this application will be implemented (i.e., these details should be fully understood by those skilled in the art). While specific details (e.g., circuits) have been set forth to describe exemplary embodiments of this application, it will be apparent to those skilled in the art that the embodiments of this application can be implemented without these specific details or with variations thereof. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0091] Although this application has been described in conjunction with specific embodiments thereof, many substitutions, modifications, and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may be used with the embodiments discussed.

[0092] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.

Claims

1. A method for processing phase difference data based on dual-polarized GNSS occultation, characterized in that, include: The low-Earth orbit satellite orbit is obtained by precise orbit determination using LEO observation data and positioning auxiliary data; Based on the low-Earth orbit satellite orbit and time-registered phase data, atmospheric additional phase data for channels H and V are calculated and geometrically co-registered to determine the spatiotemporal location of the occultation event; wherein, the time-registered phase data is obtained based on the synchronization and phase reconstruction of dual-polarized occultation data for channels H and V; Polarization phase difference is constructed based on the phase data after geometric co-registration to obtain phase difference data, and phase difference cycle slip repair is performed based on the phase difference data; The differential phase sequence after cycle slip repair is processed to output a phase difference product; wherein, the data processing includes normalization processing, phase difference smoothing processing, and removal of linear trends; The normalization process involves estimating the constant bias based on the signal-to-noise ratio and weighting coefficients using the least squares estimation method to obtain the differential phase after removing the constant bias. The constant bias formula is as follows: ； In the formula, This represents the constant bias obtained from the estimation; Indicates the bias search value; express The weighting coefficient at any given time; H is the index range of the tangent point height within a preset height; This indicates the search for the minimum value of the objective function. value; and They represent Signal-to-noise ratio of the H channel and V channel at time; This represents the differential phase after removing the constant bias.

2. The method according to claim 1, characterized in that: I / Q data synchronization is achieved by using a cross-correlation function to find the optimal time delay alignment between the H-channel and V-channel signals. The specific formula is as follows: ； In the formula, It means The complex baseband signal of the channel; express The complex baseband signal of the channel; and These represent in-phase and quadrature components, respectively; Represents the imaginary unit; Indicates the first The timestamp of each sampling moment; express Channel at time The complex conjugate of the complex baseband signal; τ represents the time delay search range; Typically, the sampling interval is ±1. This indicates the search for the value of τ that maximizes the cross-correlation function.

3. The method according to claim 1, characterized in that: The geometric co-registration establishes a correspondence between the differential phase at each sampling time and the geometric position of the corresponding occultation tangent point. The formula for the occultation tangent point height is as follows: ； In the formula, for The unit line-of-sight vector at any given time; for The position vector of the GNSS satellite at that moment; for The position vector of the LEO receiver at that moment; The tangent parameter represents the distance from the LEO receiver position along the line of sight to the tangent point; for The position vector of the tangent point at time moment represents the position of the point of tangency between the signal path and the Earth's surface in the geocentric-geofixed coordinate system; for The height of the tangent point at any given moment; The length of the module at the tangent point; The radius is the Earth's radius.

4. The method according to claim 1, characterized in that: The phase difference cycle slip correction involves correcting half-cycle slips during the closed-loop period and full-cycle slips during the open-loop period. The cycle slip correction formula is as follows: ； in, , and They represent channels respectively. and exist Phase of time, This indicates the phase difference after cycle slip correction.

5. The method according to claim 1, characterized in that: The removal of linear trends involves using phase difference data at tangent heights above 20km and fitting the linear trend of the difference phase sequence based on least squares to remove the linear trend from the smoothed phase difference.

6. A phase difference data processing system based on dual-polarized GNSS occultation, characterized in that, include: The precision orbit determination module is configured to obtain the low Earth orbit satellite orbit by performing precise orbit determination on LEO observation data and positioning assistance data; The geometric co-registration module is configured to calculate atmospheric additional phase data for the H and V channels based on the low-Earth orbit satellite orbit and time-registered phase data, and perform geometric co-registration to determine the spatiotemporal location of the occultation event; wherein the time-registered phase data is obtained based on the synchronization and phase reconstruction of dual-polarized occultation data for the H and V channels; The cycle slip repair module is configured to construct a polarization phase difference based on the phase data after geometric co-registration to obtain phase difference data, and to perform phase difference cycle slip repair based on the phase difference data. The data processing module is configured to process the differential phase sequence after cycle slip repair to output a phase difference product; wherein, the data processing includes normalization processing, phase difference smoothing processing, and removal of linear trends; The normalization process involves estimating the constant bias based on the signal-to-noise ratio and weighting coefficients using the least squares estimation method to obtain the differential phase after removing the constant bias. The constant bias formula is as follows: ； In the formula, This represents the constant bias obtained from the estimation; Indicates the bias search value; express The weighting coefficient at any given time; H is the index range of the tangent point height within a preset height; This indicates the search for the minimum value of the objective function. value; and They represent Signal-to-noise ratio of the H channel and V channel at time; This represents the differential phase after removing the constant bias.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the method as described in any one of claims 1-5.

8. A non-transitory computer-readable storage medium, characterized in that, in, The non-transitory computer-readable storage medium stores computer instructions for causing a computer to perform the method described in any one of claims 1-5.

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