Method for processing frequency offsets of pseudoranges in a glonass system

Abstract

The embodiment of the application discloses a method for processing pseudorange inter-frequency bias in a GLONASS system. The method is applied to a multi-GNSS system, and the method comprises the following steps: when an observation environment meets a preset condition, obtaining position information of a mobile station by using non-GLONASS system satellite observations; obtaining pseudorange single-difference values of each GLONASS satellite by using the position information of the mobile station and pseudorange observations of each GLONASS common-view satellite of the mobile station and a base station; calculating pseudorange double-difference values of each GLONASS satellite except for a selected GLONASS reference satellite, and further determining the pseudorange inter-frequency bias values of each satellite in the GLONASS system; obtaining stable pseudorange inter-frequency bias values of each GLONASS satellite by filtering; and when the observation environment is poor, compensating the pseudorange inter-frequency bias values of the GLONASS satellites and then participating in positioning, so as to improve the pseudorange differential positioning performance.

Description

TECHNICAL FIELD

[0001] The embodiment of the present application relates to the field of Global Navigation Satellite System (GNSS) navigation positioning technology, in particular to a method for processing inter-frequency channel bias of pseudorange in GLONASS system. BACKGROUND

[0002] At present, GNSS includes GPS of the United States, BDS of China, GLONASS of Russia and Galileo of the European Union. Among them, GPS, BDS and Galileo system adopt Code Division Multiple Access (CDMA) technology, the frequencies of satellites in the system are the same, while GLONASS adopts Frequency Division Multiple Access (FDMA) technology, different frequencies of satellites are received by different radio frequency channels of the receiver, thus different inter-frequency channel bias (IFB) is generated, generally IFB can be as high as several meters, which will affect the positioning accuracy, therefore, the IFB of the pseudorange in GLONASS system needs to be estimated and compensated. At present, the estimation method of GLONASS pseudorange IFB is mainly to model the IFB of the pseudorange in GLONASS system according to the characteristics that the IFB of the pseudorange in GLONASS system is related to the frequency, but this method is not suitable for various types of receivers, and the IFB of the receiver will change with time, therefore, this method cannot accurately describe the IFB of the pseudorange in GLONASS system.

[0003] In the prior art, the double difference observation equation between stations or between satellites can be constructed based on the GLONASS pseudorange observation data of zero baseline or short baseline, and the pseudorange IFB value is obtained through the double difference observation equation, the relationship between the pseudorange IFB and the satellite frequency number is analyzed, the parameter of the change of IFB with the difference value of frequency number is introduced, the pseudorange IFB error of each satellite is absorbed, and thus the differential positioning accuracy of GLONASS pseudorange is improved. The technology calculates the IFB value by constructing a frequency linear relationship model, this method can only be suitable for part of the receivers, and due to the fact that the model cannot be determined whether the data at the time is used in real-time positioning, the application of the technology has great limitations; in addition, when the frequency linear relationship is constructed, only the observation of GLONASS satellite is used, so that the accuracy of the estimation result of the IFB is not high. SUMMARY

[0004] In order to solve any of the above technical problems, the embodiment of the present application provides a method for processing inter-frequency channel bias of pseudorange in GLONASS system.

[0005] To achieve the purpose of the embodiments of the present application, the embodiments of the present application provide a method for processing frequency bias of pseudorange in GLONASS system, which is applied to a multi-GNSS system including a GLONASS system and at least one non-GLONASS system, and the method comprises:

[0006] When the observation environment of the multi-GNSS system meets a preset condition, the position information of a mobile station is obtained by using a pseudorange observation equation of a satellite of the non-GLONASS system;

[0007] The position information of the mobile station and pseudorange observation values of each GLONASS common-view satellite of the mobile station and a base station are used to obtain pseudorange single-difference values of each common-view satellite;

[0008] The double-difference values of the frequency bias of the pseudorange of each satellite in the GLONASS system are determined according to the difference between the pseudorange single-difference values of each common-view satellite and a reference star.

[0009] Further, the double-difference values of the frequency bias of the pseudorange of each satellite in the GLONASS system are determined according to the difference between the pseudorange single-difference values of each common-view satellite and a reference star, and the method comprises:

[0010] A common-view satellite with the highest elevation angle or the best tracking quality in the GLONASS system is selected as the reference star, the difference between the pseudorange single-difference equations of each common-view satellite in the GLONASS system and the reference star is calculated, and a pseudorange double-difference equation is obtained;

[0011] The double-difference values of the frequency bias of the pseudorange of any common-view satellite in the GLONASS system are obtained through the pseudorange double-difference equation.

[0012] When the observation environment of the multi-GNSS system does not meet the preset condition, the filtering estimation of the frequency bias values of the pseudorange of each satellite in the GLONASS system is stopped, the pseudorange differential positioning is performed by using the GLONASS satellites, the frequency bias values of the pseudorange are compensated, and the performance of the pseudorange differential positioning is improved.

[0013] A storage medium, in which a computer program is stored, wherein the computer program is configured to execute the method described above when running.

[0014] An electronic device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor is configured to execute the computer program to perform the method described above.

[0015] One of the above technical solutions has the following advantages or beneficial effects:

[0016] When the observation environment of the multi-GNSS system meets preset conditions, the position information of the mobile station is obtained by using the pseudo-range observation equation of the satellite of the non-GLONASS system, the pseudo-range single-difference values of the common-visibility satellites are obtained by using the position information of the mobile station and the pseudo-range observation values of the common-visibility satellites of the GLONASS system of the mobile station and the base station, the frequency interval bias values of the satellites of the GLONASS system are determined according to the difference between the pseudo-range single-difference values of the common-visibility satellites and the reference satellite, and the frequency interval bias of the pseudo-range of the GLONASS system is obtained, and the calculation accuracy of the frequency interval bias value is improved.

[0017] Other features and advantages of the embodiments of the present application will be set forth in the following description, and in part will become apparent from the description, or can be learned by practice of the embodiments of the present application. The objects and other advantages of the embodiments of the present application will be realized and achieved by means specified in the description, claims and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings are included to provide a further understanding of the technical solutions of the embodiments of the present application, and constitute a part of the specification, and are used to explain the technical solutions of the embodiments of the present application together with the embodiments of the present application, and do not constitute a limitation to the technical solutions of the embodiments of the present application.

[0019] Figure 1 The flow chart of the processing method of the frequency interval bias of the pseudo-range of the GLONASS system provided by the embodiments of the present application is shown in the figure;

[0020] Figure 2 Another flow chart of the processing method of the frequency interval bias of the pseudo-range of the GLONASS system provided by the embodiments of the present application is shown in the figure;

[0021] Figure 3 The flow chart of the processing method of the position information of the mobile station provided by the embodiments of the present application is shown in the figure;

[0022] Figure 4 The flow chart of the processing method of the frequency interval bias of the pseudo-range of the GLONASS system provided by the embodiments of the present application is shown in the figure;

[0023] FIG. 5(a) is a positioning error schematic diagram of the co-positioning operation of the GPS system and the GLONASS system in the prior art;

[0024] FIG. 5(b) is a positioning error schematic diagram of the co-positioning operation of the GPS system and the GLONASS system in the present application;

[0025] FIG. 6(a) is a positioning error schematic diagram of the independent positioning operation of the GLONASS system in the prior art;

[0026] Fig. 6(b) is a diagram of positioning error of the GLONASS system independent positioning operation in the present application. DETAILED DESCRIPTION

[0027] To make the objects, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application will be described in detail below with reference to the drawings. It should be explained that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other at will.

[0028] Figure 1 The flow chart of the method for processing the inter-frequency bias of the pseudorange in the GLONASS system provided by the embodiments of the present application is shown in Fig. 6(a). As shown in Fig. 6(a), the method is applied to a multi-GNSS system, the multi-GNSS system includes the GLONASS system and at least one non-GLONASS system, and the method includes the following steps. Figure 1

[0029] Step 101: When the observation environment of the multi-GNSS system meets a preset condition, the position information of the mobile station is obtained by using the pseudorange observation equation of the satellite of the non-GLONASS system.

[0030] The non-GLONASS system can be at least one of the GPS system, the BDS system and the Galileo system. The observation environment of the multi-GNSS system can be determined according to the reception quality of the satellite signal, and can also be determined in combination with the number of satellites that can be observed at present.

[0031] Step 102: The single-difference value of the pseudorange of each GLONASS common- view satellite is obtained by using the position information of the mobile station and the pseudorange observation value of each GLONASS common-view satellite of the mobile station and the base station.

[0032] The single-difference value of the pseudorange of the GLONASS common-view satellite includes the difference between the satellite-geodetic distance of the mobile station and the base station, the difference between the inter-frequency biases of the mobile station and the base station, the difference between the receiver clock biases of the mobile station and the base station, and the single-difference observation noise of the pseudorange.

[0033] Step 103: The inter-frequency bias value of the pseudorange of each satellite in the GLONASS system is determined according to the difference between the single-difference values of the pseudorange between each common-view satellite and the reference satellite.

[0034] Specifically, when the position of the mobile station is obtained by using the pseudorange difference positioning of the GLONASS system, the inter-frequency bias value of the satellite pseudorange needs to be used. The position of the mobile station determined by the non-GLONASS system is taken as a known quantity, which is substituted into the pseudorange observation equation of the GLONASS system, so that the inter-frequency bias value of the pseudorange between each common-view satellite at the current time can be deduced.

[0035] ​Since the position information of the mobile station is obtained when the observation environment of the multi-GNSS system is good, the position information of the mobile station is accurate. The pseudo-range inter-frequency bias values of the respective common-view satellites are obtained based on the accurate position information of the mobile station, and the accuracy of the inter-frequency bias values is improved.

[0036] Preferably, a GLONASS satellite with the highest elevation angle or the best tracking quality is selected as a reference satellite, and the pseudo-range inter-frequency bias values of the respective satellites in the GLONASS system are determined based on the position information of the mobile station and the difference between the single-difference values of the pseudo ranges between the respective common-view satellites and the reference satellite.

[0037] Specifically, after the single-difference values of the pseudo ranges of the respective common-view satellites in the GLONASS system are obtained, a satellite with the highest elevation angle or the best tracking quality can be selected as a reference satellite, and the inter-frequency bias of the satellite is set to 0. The inter-frequency bias values of the pseudo ranges of the other satellites can be obtained based on the difference between the single-difference values of the pseudo ranges, and the inter-frequency bias values of the pseudo ranges of the respective satellites in the GLONASS system can be obtained in the same way, so as to achieve the purpose of obtaining the inter-frequency bias values.

[0038] The method provided by the embodiments of the present application uses the pseudo-range observation equation of the non-GLONASS system satellite to obtain the position information of the mobile station when the observation environment of the multi-GNSS system meets the preset condition, obtains the single-difference values of the pseudo ranges of the respective common-view satellites based on the position information of the mobile station and the pseudo-range observation values of the respective GLONASS common-view satellites of the mobile station and the base station, determines the inter-frequency bias values of the pseudo ranges of the respective satellites in the GLONASS system based on the difference between the single-difference values of the pseudo ranges between the respective common-view satellites and the reference satellite, and achieves the purpose of obtaining the inter-frequency bias of the pseudo range in the GLONASS system, and improves the calculation accuracy of the inter-frequency bias values.

[0039] Figure 2 Another flowchart of the processing method of the inter-frequency bias of the pseudo range in the GLONASS system provided by the embodiments of the present application is shown in FIG. 6. Figure 2 As shown in FIG. 6, the method comprises the following steps.

[0040] In step 201, the mobile station and the base station obtain measurement information.

[0041] In step 201, the mobile station and the base station obtain measurement information.

[0042] In step 202, it is determined whether the current observation environment is good.

[0043] If the current observation environment is good, the current mobile station position information is obtained after step 206 is performed on the non-GLONASS system satellite, and then steps 203 and 204 are performed to calculate the current stable GLONASS system pseudo-range IFB; otherwise, steps 205 and 206 are directly performed on the GLONASS system satellite, and then steps 206 are performed on the non-GLONASS system and the GLONASS system after the IFB is compensated.

[0044] Step 203, obtaining mobile station position information.

[0045] The mobile station position information can be obtained by pseudo-range differential positioning calculation using non-GLONASS system pseudo-range information.

[0046] Step 204, calculating the GLONASS system pseudo-range IFB using the obtained mobile station position information.

[0047] Step 205, compensating the GLONASS system pseudo-range IFB using the obtained pseudo-range IFB when the current observation environment does not meet the condition.

[0048] Step 206, performing pseudo-range differential positioning calculation using the non-GLONASS system satellite when the observation environment is good, or using the GLONASS system satellite and other system satellites after the IFB is compensated when the observation environment does not meet the condition, to obtain the pseudo-range differential positioning result.

[0049] Step 207, outputting the pseudo-range differential positioning result.

[0050] The method provided by the embodiment of the present application uses the pseudo-range observation equation of the non-GLONASS system satellite to obtain the position information of the mobile station when the observation environment of the multi-GNSS system is good, uses the position information of the mobile station and the pseudo-range observation values of the GLONASS common-observation satellites of the mobile station and the base station to obtain the single-difference values of the pseudo-ranges of the common-observation satellites, determines the frequency interval bias values of the pseudo-ranges of the satellites in the GLONASS system according to the difference values of the pseudo-range single-differences of the common-observation satellites and the reference satellites, and achieves the purpose of obtaining the frequency interval bias of the pseudo-range in the GLONASS system, and improves the calculation accuracy of the frequency interval bias values. When the observation environment of the multi-GNSS system does not meet the preset condition, the positioning is performed using the pseudo-range frequency interval bias values with improved accuracy, and the positioning operation accuracy of the GLONASS system can be improved.

[0051] The method provided by the embodiment of the present application is described below:

[0052] The embodiment of the present application provides a processing method of the IFB of the pseudo-range in the GLONASS system, which is applied to pseudo-range differential positioning to improve the positioning performance. The method includes the following three parts:

[0053] Step A, when the GNSS signal is good, the pseudorange observation equation of the non-GLONASS system is used to obtain high-precision mobile station position information.

[0054] Wherein, the GNSS satellite pseudorange observation equation is as follows:

[0055] P = r + IFB + c * Δt - c * (Δt s -Tgd) + Iono + Trop + ε (1)

[0056] Wherein, P represents the satellite pseudorange observation value, r represents the geometric distance between the satellite and the receiver, IFB represents the pseudorange frequency bias, c represents the speed of light, Δt represents the receiver clock error, Δt s represents the satellite clock error, Tgd represents the satellite end signal group delay, Iono represents the ionospheric delay, Trop represents the tropospheric delay, and ε represents the pseudorange observation noise.

[0057] Figure 3 The flowchart of the mobile station position information acquisition method provided by the embodiment of the application is shown in FIG. 1. Figure 3 As shown in the figure, step A includes the following flow:

[0058] Step A1, obtaining the pseudorange observation equation of the same common view satellite of the mobile station and the base station in the same non-GLONASS system;

[0059] According to the calculation expression (1), the common view satellite i of the mobile station r and the base station b is selected, and the pseudorange observation equation of the common view satellite i of the mobile station r and the base station b is obtained respectively, see calculation expression (2) and calculation expression (3):

[0060]

[0061] In the above calculation expression (2) and calculation expression (3), the frequencies of each satellite in the GPS / BDS / Galileo system are the same, so IFB = 0 in the pseudorange observation equation.

[0062] Step A2, calculating the difference between the corresponding pseudorange observation equations of the mobile station and the base station to obtain the pseudorange single difference equation based on the same common view satellite in the same non-GLONASS system;

[0063] In the zero baseline or short baseline scenario, the ionospheric delay and the tropospheric delay of the base station and the mobile station have spatial correlation, so at this time the ionospheric delay and the tropospheric delay of the base station and the mobile station can be considered to be approximately equal; further, the difference between the calculation expression (2) and the calculation expression (3) can eliminate the satellite clock error Δt i , the satellite end signal group delay Tgd i, ionospheric delay Iono and tropospheric delay Trop, etc. to obtain the pseudo-range single-difference equation, as shown in the calculation expression (4):

[0064]

[0065] The calculation expression (4) is transformed to obtain the calculation expression (5):

[0066]

[0067] In the calculation expression (5), is the pseudo-range single-difference value of the mobile station r and the base station b on the same satellite, which can be calculated by the pseudo-range observation value; is the distance between the satellite i and the base station b, wherein the satellite coordinates are calculated by the broadcast ephemeris, and the base station coordinates are accurately known, so that can be directly calculated; is the observation noise after the pseudo-range difference; Δt rb is the clock difference of the mobile station r and the base station b on the same satellite.

[0068] Step A3, using the pseudo-range single-difference equation of at least four common-view satellites, the position information of the mobile station is obtained;

[0069] The mobile station can obtain the pseudo-range measurement equation of each common-view satellite similar to the calculation expression (5) by tracking multiple common-view satellites, and the high-precision position of the mobile station and the difference Δt rb between the clock differences of the mobile station and the base station can be obtained by using the least square algorithm or the Kalman filtering algorithm.

[0070] Step B, using the high-precision position information of the mobile station and the GLONASS pseudo-range double-difference observation equation, the pseudo-range IFB of each satellite in the GLONASS system is obtained.

[0071] Figure 4 The flowchart of the method for obtaining the pseudo-range IFB of each satellite in the GLONASS system provided by the embodiment of the application is shown in FIG. 2. Figure 4 As shown in FIG. 2, the step B includes the following flow:

[0072] Step B1, obtaining the pseudo-range observation equation of the mobile station and the base station on the same common-view satellite in the GLONASS system;

[0073] According to the calculation expression (1), the pseudo-range observation equation of the mobile station r and the base station b on the common-view satellite i in the GLONASS system at the time t0 is obtained, as shown in the calculation expression (6) and the calculation expression (7):

[0074]

[0075] Step B2, calculate the difference between the pseudo-range observation equation of the mobile station and the pseudo-range observation equation of the base station based on the same common view satellite, to obtain the pseudo-range single-difference equation based on the same common view satellite in the GLONASS system;

[0076] By calculating the difference between the calculation expression (6) and the calculation expression (7), according to the spatial correlation characteristics of the error, the GLONASS pseudo-range single-difference model formula (8) is obtained:

[0077]

[0078] Similarly, the pseudo-range single-difference model calculation expression (9) of the mobile station r and the base station b in the GLONASS system of the common view satellite j can be obtained:

[0079]

[0080] Step B3, calculate the difference between the pseudo-range single-difference equations of any two common view satellites in the GLONASS system, to obtain the pseudo-range double-difference equation;

[0081] Taking satellite j as the reference satellite, which is the satellite with the highest elevation angle or the best tracking quality, the difference between the calculation expression (8) and the calculation expression (9) can eliminate the receiver clock error, and the pseudo-range double-difference model calculation expression (10) between satellite i and satellite j in the GLONASS system is obtained:

[0082]

[0083] Step B4, solve the pseudo-range double-difference equation to obtain the frequency interval deviation of the pseudo-range of any common view satellite in the GLONASS system;

[0084] The double-difference value of the pseudo-range frequency interval deviation of the GLONASS satellites i and j can be obtained by calculating the calculation expression (10) Calculate the calculation expression (11):

[0085]

[0086] Solve the pseudo-range double-difference equation to obtain the frequency interval deviation of the pseudo-range of any two common view satellites in the GLONASS system in the calculation expression (11), is the pseudo-range double-difference observation value, which is obtained by the pseudo-range observation of the mobile station r and the base station b; is the double-difference value of the geodetic distance, the coordinates of the satellites i and j are calculated by the broadcast ephemeris, the coordinates of the base station are accurately known, and the high-precision position information of the mobile station is obtained by the pseudo-range differential positioning of the GPS / BDS / Galileo satellites in step A, so can be obtained by calculation; The error term can be ignored after the pseudo-range double-difference observation noise is weakened by carrier phase smoothing and other methods.

[0087] Similarly, the double-difference value of the pseudo-range IFB of each GLONASS satellite (j1, j2,..., jN) can be obtained by calculating expression (11), which is relatively stable in a period of time. n

[0088] Further, the double-difference value of the pseudo-range IFB of each GLONASS satellite is filtered and estimated. The double-difference estimation value of the pseudo-range IFB of satellite i and j at the current time t is calculated by expression (12):

[0089]

[0090] wherein, is the double-difference estimation value of the pseudo-range IFB of satellite i and j at t-1; is the double-difference calculation value of the pseudo-range IFB of satellite j at the current time t; ω is the weight of the double-difference estimation value of the pseudo-range IFB of satellite i and j at t-1, and (1-ω) is the weight of the double-difference calculation value of the pseudo-range IFB of satellite i and j at the current time t. The weights can be dynamically adjusted according to the accuracy of the double-difference estimation value of the pseudo-range IFB at t-1 and the double-difference calculation value of the pseudo-range IFB at the current time t. When the double-difference estimation value of the pseudo-range IFB at t-1 has higher accuracy and the double-difference calculation value of the pseudo-range IFB at the current time t has lower accuracy, the weight ω is increased, and vice versa. The double-difference value estimation method of the pseudo-range IFB is applicable to the pseudo-range observation of each frequency point of the GLONASS satellite.

[0091]

[0092] Let the reference star be Then the above formula is converted to:

[0093]

[0094] Through the above steps, the pseudo-range IFB value of each GLONASS satellite can be obtained And the IFB value of each GLONASS satellite obtained by the above method is more accurate.

[0095] Step C, using the pseudo-range IFB of the GLONASS system for positioning operation

[0096] ​In the case that GNSS observation environment is poor and the number of satellites of other GNSS systems (GPS / BDS / Galileo) is small, the filtering estimation of GLONASS pseudorange IFB is stopped, and GLONASS satellites are used for pseudorange differential positioning. The pseudorange single-difference observation equation of GLONASS satellites is:

[0097]

[0098] The above formula is converted to:

[0099]

[0100] In the calculation of expression (15), is the pseudorange single-difference value of the GLONASS satellite between the mobile station and the base station, which is calculated by the pseudorange measurement value; is the distance between the satellite and the base station, wherein the satellite coordinates are calculated by the broadcast ephemeris, and the base station coordinates are accurately known, so that is obtained by formula (13); the right side is the mobile station position and clock bias term to be solved. Further, expression (15) is calculated by the pseudorange measurement equation of the GLONASS satellite and expression (5) is calculated by the pseudorange measurement equation of other GNSS satellites, so that positioning is performed by the least square or Kalman filtering algorithm, thereby improving the pseudorange differential positioning accuracy and improving the positioning performance.

[0101] After the GLONASS pseudorange IFB estimation method provided by the embodiment of the present application is used in pseudorange differential positioning, the pseudorange differential positioning result accuracy is obviously improved when the satellite participates in positioning in the GLONASS system. The GLONASS pseudorange IFB estimation method provided by the present application does not depend on the linear relationship of the frequency and has universality, and can be compatible with various types of receivers.

[0102] FIGS. 5(a) and 5(b) are positioning error diagrams of the common positioning operation of the GPS system and the GLONASS system in the prior art and the present application, respectively. The result shown in FIG. 5(a) is the pseudorange differential positioning result without GLONASS pseudorange IFB estimation and compensation, and the result shown in FIG. 5(b) is the pseudorange differential positioning result after the GLONASS system pseudorange IFB is estimated and compensated. By comparison, it can be seen that the positioning error shown in FIG. 5(b) is smaller than that shown in FIG. 5(a), wherein the height direction (HGT) error RMS value is reduced by about 25 cm, and the horizontal direction (HOR) error RMS value is reduced by about 34 cm.

[0103] Fig. 6(a) and Fig. 6(b) are positioning error diagrams of the prior art and the GLONASS system independent positioning operation of the present application, respectively. The result shown in Fig. 6(a) is the pseudo-range differential positioning result without GLONASS pseudo-range IFB estimation and compensation, and the result shown in Fig. 6(b) is the pseudo-range differential positioning result after the GLONASS system pseudo-range IFB is estimated and compensated. By comparison, it can be seen that the positioning error shown in Fig. 6(b) is less than that shown in Fig. 6(a), in which the height direction (HGT) error RMS value is reduced by about 1.75 m, and the horizontal direction (HOR) error RMS value is reduced by about 1.56 m.

[0104] An embodiment of the present application provides a storage medium, wherein the storage medium stores a computer program, and the computer program is configured to execute the method in any one of the preceding embodiments when running.

[0105] An embodiment of the present application provides an electronic device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor is configured to execute the computer program to execute the method in any one of the preceding embodiments.

[0106] Those of ordinary skill in the art can understand that all or some of the steps in the above disclosed method, the functions of the modules / units in the system and the device can be implemented as software, firmware, hardware or a suitable combination thereof. In the hardware implementation, the division between the function modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, one physical component can have multiple functions, or one function or step can be performed by several physical components in cooperation. Some or all of the components can be implemented as software executed by a processor such as a digital signal processor or a microprocessor, or as hardware, or as an integrated circuit such as an application specific integrated circuit. Such software can be distributed on a computer readable medium, which can include computer storage media (or non-transitory media) and communication media (or transitory media). As known by those of ordinary skill in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. Furthermore, as known by those of ordinary skill in the art, communication media typically includes computer readable instructions, data structures, program modules or other data in modulated data signals such as carrier waves or other transport mechanisms, and can include any information delivery medium.

Claims

1. A method for processing inter-frequency biases of pseudoranges in a GLONASS system, applied to a multi-GNSS system comprising a GLONASS system and at least one non-GLONASS system, the method comprising: when an observation environment of the multi-GNSS system satisfies a preset condition, obtaining position information of a mobile station by using a pseudorange observation equation of a satellite of the non-GLONASS system; obtaining pseudorange single-difference values of each common-visibility satellite by using the position information of the mobile station and pseudorange observation values of each GLONASS common-visibility satellite of the mobile station and a base station; determining double-difference values of inter-frequency biases of pseudoranges of each satellite in the GLONASS system according to differences between the pseudorange single-difference values of each common-visibility satellite and a reference satellite, including: selecting a common-visibility satellite with the highest elevation angle or the best tracking quality in the GLONASS system as the reference satellite, calculating differences between pseudorange single-difference equations of each common-visibility satellite in the GLONASS system and the reference satellite to obtain a pseudorange double-difference equation; and obtaining the double-difference values of the inter-frequency biases of the pseudoranges of any common-visibility satellite in the GLONASS system through the pseudorange double-difference equation, including: obtaining double-difference values of the inter-frequency biases of the pseudoranges of the reference common-visibility satellites i and j based on the pseudorange double-difference values, double-difference values of slant ranges and pseudorange double-difference observation noises, wherein the pseudorange double-difference values refer to pseudorange double-difference values of the mobile station and the base station based on the common-visibility satellites i and j in the GLONASS system; filtering and estimating the double-difference values of the inter-frequency biases of each GLONASS satellite, and obtaining double-difference estimation values of the inter-frequency biases of the pseudoranges of satellites i and j at a current time t by weighted fusion of historical estimation values and current calculation values; wherein the historical estimation values refer to double-difference estimation values of the inter-frequency biases of the pseudoranges of satellites i and j at a time t-1, the current calculation values refer to double-difference calculation values of the inter-frequency biases of the pseudoranges of satellites i and j at the current time t, and the weights are dynamically adjusted according to accuracies of the double-difference estimation values of the inter-frequency biases of the pseudoranges at the time t-1 and the double-difference calculation values of the inter-frequency biases of the pseudoranges at the current time t; in a case where a single-difference estimation value of the inter-frequency bias of the pseudorange of the reference common-visibility satellite j is set to zero, obtaining a single-difference estimation value of the inter-frequency bias of the pseudorange of the common-visibility satellite i according to the double-difference estimation values of the inter-frequency biases of the pseudoranges of the reference common-visibility satellites i and j, and taking the single-difference estimation value of the inter-frequency bias of the pseudorange of the common-visibility satellite i as a single-difference value of the inter-frequency bias of the pseudorange of the satellite i.

2. The method of claim 1, wherein, The method further comprises: in a case where an observation environment of the multi-GNSS system does not satisfy a preset condition, performing pseudorange differential positioning operation using the GLONASS system by using single-difference values of inter-frequency biases of pseudoranges of satellites in the GLONASS system.

3. The method of claim 1, wherein, The method further comprises: respectively obtaining pseudorange observation equations of the same common-visibility satellite based on the mobile station and the base station; calculating differences between the corresponding pseudorange observation equations of the mobile station and the base station to obtain a pseudorange single-difference equation based on the same common-visibility satellite in the non-GLONASS system; The position information of the mobile station is obtained by using pseudo-range single-difference equations of at least four common-view satellites.

4. The method of claim 3, wherein, The calculation expression of the pseudo-range single-difference equation based on the same common-view satellites in the same non-GLONASS system is as follows: wherein is a difference between a pseudorange of a mobile station r and a base station b based on a common- view satellite i in a non-GLONASS system; is a difference between a distance of a mobile station r and a distance of a base station b from a common- view satellite i in a non-GLONASS system; c is a speed of light; Δt rb is a difference between a receiver clock of a mobile station r and a receiver clock of a base station b; is a difference between corresponding pseudorange observation noises of a mobile station r and a base station b based on a common- view satellite i in a non-GLONASS system.

5. The method of claim 1, wherein, The calculation expression of the pseudo-range single-difference equation based on the same common-view satellites in the GLONASS system is as follows: wherein is a difference between a pseudorange of the mobile station r to a common- view satellite i in the GLONASS system and a pseudorange of the base station b to the common- view satellite i in the GLONASS system; is a difference between a distance of the mobile station r to a common- view satellite i in the GLONASS system and a distance of the base station b to the common- view satellite i in the GLONASS system; is a difference between corresponding inter-frequency biases of the mobile station r and the base station b based on the common- view satellite i in the GLONASS system; c is the speed of light; Δt rb is a difference between receiver clock offsets of the mobile station r and the base station b; is a difference between corresponding pseudorange observation noises of the mobile station r and the base station b based on the common- view satellite i in the GLONASS system; The calculation expression of the pseudo-range double-difference equation is as follows: wherein: represents a pseudorange double-difference value for mobile station r and base station b based on common- view satellites i, j in the GLONASS system; is a double-difference value for pseudorange; is a pseudorange double-difference observation noise; is a double-difference value for pseudorange inter-frequency bias for common-view satellites i, j.

6. The method of claim 2, wherein: In the process of obtaining the position information of the mobile station, the difference of the receiver clock difference between the mobile station and the base station is also obtained; The pseudo-range difference-difference positioning operation using the GLONASS system satellites includes: Obtaining the pseudo-range single-difference equation of the mobile station and the base station based on the same common-view satellites of the GLONASS system; The position information of the mobile station and the difference of the receiver clock difference between the mobile station and the base station are obtained by using the pseudo-range single-difference equation of each satellite of the GLONASS system.

7. A storage medium, characterized by The storage medium stores a computer program, and the computer program is configured to execute the method in any one of claims 1 to 6 when running. 8.An electronic device comprising a memory and a processor, the electronic device comprising: The memory stores a computer program, and the processor is configured to execute the computer program to execute the method in any one of claims 1 to 6.

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