Navigation satellite system mixed signal and pilot signal deviation calibration method

Abstract

The invention discloses a navigation satellite system mixed signal and pilot signal deviation calibration method, and relates to the technical field of satellite navigation precise orbit determination and positioning. The method comprises the following steps: generating a satellite discrete orbit based on a broadcast ephemeris, gradually refining and converging through a parameter estimation method, a residual error editing method and an orbit integration method to obtain a refined orbit, solving ionosphere-free combination in-frequency inter-symbol deviation through parameter estimation, and respectively solving wide-lane UPD of a navigation satellite pilot signal and a mixed signal through MW combination; and determining the wide-lane UPD difference between the pilot frequency and the mixed signal based on the principle of minimum L1 norm of the wide-lane UPD difference between the pilot frequency signal and the mixed signal of the navigation satellite, and solving the intra-frequency inter-symbol deviation on a single frequency by combining the intra-frequency inter-symbol deviation of the ionosphere-free combination. According to the method, the precision of ambiguity fixed precision single-point positioning is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of satellite navigation precise orbit determination positioning, and particularly to a navigation satellite system mixed signal and pilot signal deviation calibration method. BACKGROUND

[0002] In satellite navigation precise orbit determination positioning, the accurate calculation of observable-specific signals bias (OSB) directly affects the accuracy and efficiency of ambiguity resolution precise point positioning (PPP-AR).

[0003] In the global navigation satellite system, Galileo E1 and E5a and BDS-3 B1C and B2a frequency bands provide data channels modulated with navigation message data and pilot channels without navigation message data. Corresponding global IGS receivers mainly provide two types of observations. One type of receiver (JAVAD and TRIMBLE) only uses the pilot component to generate carrier and pseudorange observations, so there is no bit transition problem, and long-time correlation integration can be supported to improve the quality of observation values. The other type (SEPT and LEICA) uses both pilot components and data components to generate GNSS observation values, and the signal-to-noise ratio is improved due to the combination of the power of the two signal components. However, the traditional satellite clock solution process of IGS usually selects one signal as the reference, and when calculating the clock difference jointly with different signals, the two signals need to be aligned, i.e., the deviation between the pilot signal and the mixed signal needs to be determined. However, no GNSS receiver can provide both types of observations, so the deviation between the mixed signal and the pilot signal cannot be directly obtained.

[0004] One of the existing methods for calibrating the deviation between the mixed signal and the pilot signal is to treat both the pilot and the mixed signal as reference signals, and to process the code bias between the pilot signal and the mixed signal separately, which also causes the separation of phase bias products, which is contrary to the IGS protocol that requires the phase bias to be consistent on different channels. Another method is to obtain two sets of satellite clock differences and wide-lane UPD differences for the mixed signal and the pilot signal, and jointly solve the intra-frequency code bias. However, both sets of clock differences and wide-lane UPD differences are calculated using two sets of references, which will affect the calibration of the deviation between the mixed signal and the pilot signal.

[0005] In order to solve these problems, there is an urgent need for a navigation satellite system mixed signal and pilot signal deviation calibration method. SUMMARY

[0006] To solve the above problems, the application provides a navigation satellite system mixed signal and pilot signal deviation calibration method, which aims at the problems of regarding the mixed signal and pilot signal as reference signals and non-uniform reference in the existing method, introduces ionosphere-free code bias between groups in parameter estimation, estimates only one group of clock bias, and determines the wide lane UPD difference of the two groups by using the pilot and mixed signal wide lane UPD difference L1 norm minimum principle, so as to better calibrate the navigation satellite system mixed signal and pilot signal deviation, thereby improving the precision of ambiguity fixed precise point positioning, and the specific contents are as follows: S1, obtaining satellite system related data, performing consistency check, and detecting cycle slip and removing gross errors to obtain clean observation data; S2, generating satellite discrete orbit based on broadcast ephemeris, and gradually refining and converging to obtain refined orbit by parameter estimation method, residual editing method and orbit integration method; S3, obtaining ionosphere-free code bias between groups by parameter estimation based on original pseudorange observation value and original carrier phase observation value; S4, obtaining wide lane UPD of navigation satellite pilot signal and mixed signal by MW combination respectively; S5, determining the wide lane UPD difference of pilot and mixed signal based on the wide lane UPD difference L1 norm minimum principle of navigation satellite pilot signal and mixed signal, and solving the ionosphere-free code bias between groups on a single frequency.

[0007] Preferably, the satellite system related data in S1 includes IGS station data, broadcast ephemeris data and external data; The satellite system related data is subjected to format analysis and integrity check; The IGS station data is subjected to gross error removal and cycle slip detection, the observation quality is improved, and a data quality log file is generated to obtain clean observation data.

[0008] Preferably, the specific content of S2 is that the satellite discrete orbit is generated based on the broadcast ephemeris, and the refined orbit is obtained by gradually refining and converging through the parameter estimation method, the residual editing method and the orbit numerical integration method. S201, generating satellite discrete orbit based on broadcast ephemeris, and obtaining satellite initial state parameters according to the satellite discrete orbit; S202, constructing satellite motion equation and variation equation according to the initial state parameters of the satellite and the perturbation force model parameters; S203, obtaining satellite state, state transition matrix and parameter sensitivity matrix at any time through orbit numerical integration method based on satellite motion equation and variation equation; S204, using the discrete orbit generated based on the broadcast ephemeris as an observation value, constructing an observation error equation, and obtaining correction values of initial state parameters of the satellite and perturbation force model parameters and observation value residuals by using a least square estimation method; S205, detecting cycle slips and gross errors by using a residual editing method, and updating a data quality log file; S206, iteratively performing steps S202-S205 until parameters converge to a target threshold value to obtain a refined orbit.

[0009] Preferably, the original pseudo-range observation value and the original carrier phase observation value in S3 include: IGS stations m and IGS stations n The original pseudo-range observation value of the mixed signal and the original carrier phase observation value of the pilot signal received by the stations from the navigation satellite s frequencies , frequencies ; x p The original pseudo-range observation value of the mixed signal and the original carrier phase observation value of the pilot signal received by the stations from the navigation satellite IGS stations m and IGS stations n The original pseudo-range observation value of the mixed signal and the original carrier phase observation value of the pilot signal received by the stations from the navigation satellite s frequencies , frequencies ; x p The original pseudo-range observation value of the mixed signal and the original carrier phase observation value of the pilot signal received by the stations from the navigation satellite

[0010] That is, the original pseudo-range observation value and the original carrier phase observation value of the mixed signal generated by using the pilot component and the data component on the frequency of the navigation satellite, and the original pseudo-range observation value and the original carrier phase observation value of the pilot signal generated by using only the pilot component.

[0011] Preferably, the specific content of obtaining the ionosphere-free inter-code bias by parameter estimation in S3 includes: S301, using the original pseudo-range observation value and the original carrier phase observation value to obtain ionosphere-free combination equations by eliminating first-order ionospheric delay by using ionosphere-free combination respectively; S302, recombining the ionosphere-free combination equations to eliminate rank defects to obtain standard ionosphere-free combination inter-code bias equations; Solving the standard ionosphere-free combination equations to obtain the ionosphere-free inter-code bias.

[0012] Preferably, the expression of the original pseudo-range observation value is: ; Wherein, and respectively represent the original pseudo-range observation value and the original carrier phase observation value received by the stations m and n from the s navigation satellite frequencies , frequencies​​ pilot signals on p and mixed signals x pseudorange observations; The expression of the original carrier phase observations is: ; where, and are m and n the carrier phase observations of the pilot signals on s navigation satellite frequencies , frequency pilot signals on p and mixed signals x , is s and the geometric distance between the receiver m , n , and is m , n the clock error of the receiver, is the clock error of the satellite s , and is the tropospheric delay between the satellite s and the receiver m , n , is the speed of light, and is the first order ionospheric delay between the satellite s and the receiver m , n , is the ratio of the frequency to the frequency , and are m and n the integer ambiguities of the pilot signals on s navigation satellite frequencies , frequency pilot signals on p and mixed signals x , are s the wavelengths of the navigation satellite frequencies and the frequency , and are m and n the carrier phase observations of the pilot signals on s navigation satellite frequencies , frequency pilot signal on p and mixed signals x pseudorange hardware delay, and For navigation satellites s In frequency ,frequency pilot signal on p and mixed signals x pseudorange hardware delay, and for m and n Stations on navigation satellites s frequency ,frequency pilot signal on p and mixed signals x Phase hardware delay, For satellite s In frequency ,frequency Phase hardware delay on, and For satellite s and receiver m , n Between in frequency and frequency pseudorange noise on and For satellite s and receiver m , n Between in frequency and frequency Phase noise on the surface.

[0013] Preferably, in S302, the expression for the ionospheric combination equation obtained by eliminating the first-order ionospheric delay using the ionospheric combination method on the original pseudorange observations and the original carrier phase observations is as follows: ; in: ; in, , , and They are respectively m and n The station received s Navigation satellite frequencies ,frequency pilot signal on p and mixed signals x The combination of pseudorange observations and phase observations without an ionosphere. and for m and n measured at s navigation satellite frequencies , frequencies on pilot signals p and mixed signals x a combination of pseudorange hardware delays and carrier phase hardware delays without ionosphere, for s a combination of pseudorange delays without ionosphere for pilot signals at navigation satellite frequencies , frequencies p on pilot signals for s a combination of phase delays without ionosphere at navigation satellite frequencies , frequencies on pilot signals for s a combination of integer ambiguities without ionosphere for pilot signals and mixed signals at navigation satellite frequencies p , frequencies x on pilot signals for s an intra-frequency inter-code bias at navigation satellite frequencies , frequencies on pilot signals , i.e. an intra-frequency inter-code bias without ionosphere is introduced directly in the parameter estimation, while only a set of satellite clock corrections is estimated and the phase bias of pilot signals and mixed signals is kept constant.

[0014] Preferably, to solve the rank deficiency problem in the parameter estimation, the equation of the combination without ionosphere is reorganized in S303, the clock correction absorbs the pseudorange hardware delay parameter, and the ambiguity parameter absorbs the pseudorange and phase hardware delay parameters to obtain the equation of the standard combination without ionosphere intra-frequency inter-code bias, which is expressed as: ; wherein: ; wherein, is s the IGS conventional satellite clock correction of the satellite, and are the corresponding m and n receiver clock corrections, and are respectively s pilot signals at navigation satellite frequencies , frequencies p on pilot signalsand mixed signals x of ionosphere-free combination integer ambiguity.

[0015] Preferably, the specific content of the wide-lane UPD of the navigation satellite pilot signal and the mixed signal obtained by the MW combination in S4 is: S401, using the MW combination to form the mixed signal and the wide-lane ambiguity of the pilot signal, and the wide-lane UPD, the integer separation can be obtained The decimal part, that is, the receiver and satellite wide-lane UPD; Taking the pilot signal as an example: ; Among them: ; Among them, is the difference between the integer ambiguity of the pilot signal on the frequency s of the navigation satellite , the frequency of the pilot signal p , the corresponding wide-lane ambiguity, respectively m receiver and s satellite wide-lane UPD, wide-lane wavelength; S402, using inter-satellite single difference to eliminate m and n receiver wide-lane UPD, to obtain satellite inter-satellite single difference wide-lane UPD.

[0016] Taking the pilot as an example: using satellite s 1 and s 2inter-satellite single difference to eliminate the wide-lane UPD of the receiver m , to obtain s 1 and s 2satellite inter-satellite single difference wide-lane UPD, as follows: ; Among them is the satellite m inter-satellite single difference wide-lane UPD based on the station .

[0017] S403, combined with the constraint that the average of all satellite wide-lane UPD is zero, the least square estimation method is used to obtain the wide-lane UPD of each satellite.

[0018] Combined with the constraint that the average of all satellite wide-lane UPD is zero, as follows: ; Among them, representing the number of satellites in the network, the least square estimation method is used to obtain the wide-lane UPD of each satellite.

[0019] Preferably, the pilot and mixed signal wide lane UPD difference is determined based on the navigation satellite pilot signal and the mixed signal wide lane UPD difference L1 norm minimum principle in S5, and the specific content of solving the inter-frequency code bias on a single frequency by combining the ionosphere-free combined inter-frequency code bias is as follows: The mixed signal and the pilot signal will generate two sets of wide lane UPD, and the two sets of wide lane UPD are subtracted to obtain a two sets of wide lane UPD subtraction expression: ; The two sets of wide lane UPD subtraction expression is an unknown constant, and the adjustment constant C is used to make the satellite mixed signal and the pilot signal wide lane UPD difference L1 norm minimum, and the specific content is as follows: ; Wherein is the difference between the mixed signal and the pilot signal wide lane UPD, and the and the two sets of wide lane UPD difference are used to solve the inter-frequency code bias and the inter-frequency code bias of the frequency and the frequency : ; Wherein, is the narrow lane wavelength.

[0020] In summary, compared with the prior art, the navigation satellite system mixed signal and pilot signal bias calibration method has the following beneficial effects: 1. Compared with other navigation satellite system mixed signal and pilot signal bias calibration methods, the consistency of the phase bias is ensured; 2. Compared with other navigation satellite system mixed signal and pilot signal bias calibration methods, the ionosphere-free combined inter-frequency code bias parameter is introduced in the parameter estimation, and only one set of satellite clock bias is estimated, and the satellite clock bias reference remains consistent; 3. Compared with other navigation satellite system mixed signal and pilot signal bias calibration methods, the mixed signal and pilot signal satellite wide lane UPD difference is determined based on the mixed signal and pilot signal satellite wide lane UPD difference L1 norm minimum, which alleviates the influence of using different references when solving two sets of wide lane UPD; 4. Compared with other navigation satellite system mixed signal and pilot signal bias calibration methods, the generated bias product is used for PPP-AR, and the precision of the ambiguity fixed precise point positioning is improved.

[0021] The technical method of the present application is further described below by means of the accompanying drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 A flow chart of an embodiment of the navigation satellite system mixed signal and pilot signal bias calibration method of the present application; Figure 2 A comparison chart of the positioning accuracy of ambiguity fixing for an embodiment of the present application; Figure 3 A comparison chart of the fixing rate of all ambiguities for an embodiment of the present application. DETAILED DESCRIPTION

[0023] The technical method of the present application is further described below by means of the accompanying drawings and examples. It should be noted that the relative arrangement, numerical expressions and values of the components and steps set forth in these examples do not limit the scope of the present application unless otherwise specifically stated.

[0024] The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the present application or its application or uses.

[0025] Techniques, systems, and devices known to those of ordinary skill in the relevant art can not be discussed in detail herein, but should be considered as part of the specification, where appropriate.

[0026] In all the examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not as a limitation. Thus, other examples of the exemplary embodiments can have different values.

[0027] Unless otherwise defined, technical and scientific terms used herein should have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0028] Embodiment One The present application provides a navigation satellite system mixed signal and pilot signal bias calibration method, as shown in Figure 1 The ionosphere-free inter-code bias is introduced in the parameter estimation, and the mixed signal and pilot signal wide-lane UPD difference is minimized, the influence of using different references is alleviated, and the bias between the calibrated pilot and mixed signal effectively improves the accuracy of the Precise Point Positioning with Ambiguity Resolution (PPP-AR).

[0029] S1, obtain satellite system related data, perform consistency check, and detect cycle slip and eliminate gross errors to obtain clean observation data; The next step, S1 satellite system related data includes IGS station data, broadcast ephemeris data and external data; The satellite system related data is parsed and integrity checked; The IGS station data is processed to remove gross errors and detect cycle slips, improving observation quality, and generating a data quality log file to obtain clean observation data.

[0030] S2, based on broadcast ephemeris, generate satellite discrete orbit and gradually refine and converge to obtain refined orbit through parameter estimation method, residual editing method and orbit integration method; The next step, S2, based on broadcast ephemeris, generate satellite discrete orbit and gradually refine and converge to obtain refined orbit through parameter estimation method, residual editing method and orbit numerical integration method, the specific content is: S201, based on broadcast ephemeris, generate satellite discrete orbit, and obtain satellite initial state parameters according to satellite discrete orbit; S202, according to the initial state parameters of the satellite and the perturbation force model parameters, construct the satellite motion equation and the variation equation, here all the models of the perturbation force model are adopted; S203, based on satellite motion equation and variation equation, obtain satellite state, state transition matrix and parameter sensitivity matrix at any time through numerical integration method; S204, based on the satellite discrete orbit generated by broadcast ephemeris as observation value, construct observation error equation, and obtain correction value of satellite initial state parameters and perturbation force model parameters and observation value residual by least square estimation method; S205, detect cycle slip and gross error by residual editing method, and update data quality log file; S206, iterate steps S202-S205 until the parameters converge to the target threshold to obtain refined orbit.

[0031] S3, based on original pseudorange observation value and original carrier phase observation value, obtain ionosphere-free intra-frequency differential code bias (IFDCB) by parameter estimation; The next step, S3, includes: IGS station m And IGS station n The navigation satellite s Frequency , frequency The mixed signal x And the original pseudorange observation value of the pilot signal p IGS station m ​and IGS test station n The station received navigation satellites s frequency ,frequency Mixed signals x and pilot signal p The original carrier phase observations.

[0032] The specific details of obtaining the intra-symbol bias of the non-ionospheric combination frequency through parameter estimation in S3 include: S301. Reorganize the ionosphere-free combinatorial equations to eliminate rank deficiency and obtain the standard ionosphere-free combinatorial equations. The intra-frequency code deviation of the ionosphere-free combination is obtained by solving the standard ionosphere-free combination equation.

[0033] The next step is to express the original pseudorange observations as follows: ; in, and Represent m and n The station received the S navigation satellite frequency. ,frequency pilot signal on p and mixed signals x pseudorange observations; The expression for the original carrier phase observation is: ; in, and They are respectively m and n The station received s Navigation satellite frequencies ,frequency pilot signal on p and mixed signals x Carrier phase observations; for s and receiver m , n Geometric distance between them and for m , n Receiver clock bias For satellite s The clock difference, and For satellite s and receiver m , n The tropospheric delay between them At the speed of light, and is a satellite s and a receiver m , n a first-order ionospheric delay between is a frequency and a frequency ratio, and is m and n a whole number ambiguity of a pilot signal s received by a station at a navigation satellite frequency , a pilot signal p and a combined signal x at a frequency s is a wavelength of a navigation satellite frequency and a frequency ; and is m and n a pseudorange hardware delay of a pilot signal s at a navigation satellite frequency , a pilot signal and a combined signal p at a frequency x and is a pseudorange hardware delay of a pilot signal s at a frequency , a pilot signal and a combined signal p at a frequency x and is m and n a phase hardware delay of a pilot signal s at a navigation satellite frequency , a pilot signal and a combined signal p at a frequency x is a phase hardware delay of a pilot signal s at a frequency , a pilot signal at a frequency and is a pseudorange noise between s and a receiver m , n at a frequency and a frequency and ​​​​​For satellite s and receiver m , n Between in frequency and frequency Phase noise on the surface.

[0034] In the next step, S302, the original pseudorange observations and the original carrier phase observations are respectively processed using an ionospheric-free combination to eliminate the first-order ionospheric delay, resulting in the expression for the ionospheric-free combination equation: ; in: ; in, , , and They are respectively m and n The station received s Navigation satellite frequencies ,frequency pilot signal on p and mixed signals x The combination of pseudorange observations and phase observations without an ionosphere. and for m and n measuring station s Navigation satellite frequencies ,frequency pilot signal on p and mixed signals x The ionosphere-free combination of pseudorange hardware delay and carrier phase hardware delay. for s Navigation satellite frequencies ,frequency pilot signal on p The pseudorange delay of the ionosphere-free combination, for s Navigation satellite frequencies ,frequency Phase-delayed non-ionized combination, for s Navigation satellite frequencies ,frequency pilot signal on p and mixed signals x Integer ambiguity of ionosphere-free composites for s Navigation satellite frequencies ,frequency The intra-frequency inter-symbol deviation, in particular, is directly introduced into the parameter estimation. That is, ionosphere-free combined inter-code bias is estimated, only a set of satellite clock errors is estimated, and the phase bias of pilot signals and mixed signals remains consistent.

[0035] Next, in order to solve the rank deficiency problem in parameter estimation, the ionosphere-free combined equation is reorganized, the clock error absorbs the pseudorange hardware delay parameter, and the ambiguity parameter absorbs the pseudorange and phase hardware delay parameter to obtain the standard ionosphere-free combined inter-code bias equation, which is expressed as: ; Wherein: ; Wherein, is s the IGS conventional satellite clock error of the satellite, and are the corresponding m and n receiver clock errors, and are the s pilot signals and mixed signals on the navigation satellite frequencies p and x , respectively.

[0036] S4, the wide lane uncorrected phase delay (Uncalibrated Phase Delay, UPD) of the navigation satellite pilot signal and the mixed signal is obtained by Melbourne-Wübbena (MW) combination, respectively. Next, the specific content of obtaining the wide lane UPD of the navigation satellite pilot signal and the mixed signal by MW combination in S4 is as follows: S401, the wide lane ambiguity of the mixed signal and the pilot signal and the wide lane UPD are obtained by using the MW combination, and the integer part can be obtained by rounding and separating, that is, the receiver and satellite wide lane UPD; Taking the pilot signal as an example: ; Wherein: ; Wherein, is the corresponding wide lane ambiguity obtained by differencing the integer ambiguity of the pilot signal on the navigation satellite frequencies s and , p are the m receiver and s satellite, respectively.​Satellite wide-lane UPD, for wide-lane wavelength; S402, using inter-satellite single difference to eliminate m and n The wide-lane UPD of the receiver is obtained by receiving the satellite inter-satellite single difference wide-lane UPD; Taking the pilot as an example, the wide-lane UPD of the satellite s 1 and s 2inter-satellite single difference is used to eliminate the wide-lane UPD of the receiver m , and the s 1 and s 2satellite inter-satellite single difference wide-lane UPD is obtained, which is as follows: ; Wherein is the satellite m inter-satellite single difference wide-lane UPD obtained based on the station .

[0037] S403, combined with the constraint that the average of all satellite wide-lane UPDs is zero, the least square estimation method is used to obtain the wide-lane UPD of each satellite.

[0038] Combined with the constraint that the average of all satellite wide-lane UPDs is zero, it is as follows: ; Wherein, represents the number of satellites in the network; combined with equations (8) and (9), the least square estimation method is used to obtain the wide-lane UPD of each satellite.

[0039] S5, based on the principle of minimum L1 norm of the difference between the pilot signal and the mixed signal wide-lane UPD of the navigation satellite, the difference between the pilot signal and the mixed signal wide-lane UPD is determined, and the intra-frequency code bias on a single frequency is obtained by combining the ionosphere-free combination, so as to achieve the purpose of calibrating the pilot signal and the mixed signal bias.

[0040] Next, the specific content of S5 based on the principle of minimum L1 norm of the difference between the pilot signal and the mixed signal wide-lane UPD of the navigation satellite is as follows: The mixed signal and the pilot signal will produce two sets of wide-lane UPD, and the two sets of wide-lane UPD are subtracted to obtain the subtraction expression of the two sets of wide-lane UPD:

[0041] The in the subtraction expression of the two sets of wide-lane UPD is an unknown constant, and the adjustment constant C is used to make the L1 norm of the difference between the satellite mixed signal and the pilot signal wide-lane UPD minimum, which is as follows: ; where is the difference of mixed signal and pilot signal wide-lane UPD, using and two sets of wide-lane UPD differences , jointly solve the frequency and the intra-frequency code bias of frequency and : ; where, is the narrow-lane wavelength.

[0042] Embodiment two Using the generated observation signal bias products, combined with satellite orbit, clock difference and attitude products, Ambiguity Resolution (AR) of Precise Point Positioning (PPP-AR) is carried out, and the strategy of PPP-AR is shown in Table 1: Table 1 Strategy of PPP-AR

[0043] The time series of positioning error RMS and ambiguity resolution rate average of Figure 2 and Figure 3 are obtained by PPP-AR, and the positioning error RMS and ambiguity resolution rate average of all stations in Table 2 are obtained, Figure 2 and Figure 3 Pilot-singals in and Mixed-singals in Pilot- and Mixed-singals contain pilot signal and mixed signal, and the final products of Huazhong University of Science and Technology (HUSf), the final products of Groupede Recherche en Géodésie Spatiale (GRGf) and the rapid products of Wuhan University (WUMr) represent HUS0MGXFIN, GRG0MGXFIN and WUM0MGXRAP products respectively.

[0044] Table 2 Positioning error RMS and ambiguity resolution rate average of HUSf, GRGf and WUMr products

[0045] From Table 2 and Figure 2 and​Figure 3 It is concluded that the east direction and north direction of HUSf product mixed signal, and the positioning accuracy and ambiguity fixing rate of pilot signal and mixed signal north direction are superior to GRGf and WUMr product, the east direction of pilot signal and mixed signal, the north direction of pilot signal, and the elevation direction positioning accuracy are between the two.

[0046] The application considers introducing ionosphere-free inter-code bias in parameter estimation, estimating only one set of satellite clock error, and making the mixed signal and pilot signal wide-lane UPD difference L1 norm minimum, finally solving the inter-code bias by combining the ionosphere-free inter-code bias and the mixed signal and pilot signal wide-lane UPD difference. Finally, compared with the traditional navigation satellite mixed signal and pilot signal bias calibration method, the application improves the positioning accuracy and ambiguity fixing rate.

[0047] Finally, it should be noted that: the above examples are only used to illustrate the technical method of the application rather than limit it, although the application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that: the technical method of the application can still be modified or replaced by the equivalent, and these modifications or equivalent replacements cannot make the modified technical method deviate from the spirit and scope of the technical method of the application.

Claims

1. A method for calibrating the deviation between mixed signals and pilot signals in a navigation satellite system, characterized in that, Includes the following steps: S1. Acquire relevant data from the satellite system, perform consistency checks on the relevant data, and detect cycle slips and remove gross errors to obtain clean observation data; S2. Based on broadcast ephemeris, discrete satellite orbits are generated and refined through parameter estimation, residual editing and orbit integration methods to achieve convergence. S3. Based on the original pseudorange observations and the original carrier phase observations, the inter-symbol deviation within the ionospheric combination frequency is obtained through parameter estimation. S4. Obtain the wide-lane UPD of navigation satellite pilot signals and mixed signals respectively through MW combination; S5. Based on the principle of minimizing the L1 norm of the wide-lane UPD difference between navigation satellite pilot signals and mixed signals, the wide-lane UPD difference between pilot signals and mixed signals is determined, and the intra-frequency inter-symbol deviation at a single frequency is obtained by combining the intra-frequency inter-symbol deviation of the non-ionospheric combination.

2. The method for calibrating the deviation between mixed signals and pilot signals in a navigation satellite system according to claim 1, characterized in that, Data related to the S1 satellite system includes IGS station data, broadcast ephemeris data, and external data. Perform format parsing and integrity checks on satellite system-related data; Gross errors were removed and cycle slips were detected from the IGS station data, and a data quality log file was generated to obtain clean observation data.

3. The method for calibrating the deviation between mixed signals and pilot signals in a navigation satellite system according to claim 2, characterized in that, In S2, the satellite discrete orbit is generated based on broadcast ephemeris and then refined and converged step by step using parameter estimation, residual editing, and orbit numerical integration methods to obtain the refined orbit. The specific content of the refined orbit is as follows: S201. Generate satellite discrete orbits based on broadcast ephemeris, and obtain satellite initial state parameters based on satellite discrete orbits; S202. Construct the satellite's motion equations and variational equations based on the satellite's initial state parameters and perturbation model parameters; S203. Based on the satellite motion equations and variational equations, the satellite state, state transition matrix, and parameter sensitivity matrix at any time are obtained through the orbital numerical integration method. S204. Using the discrete orbits generated based on broadcast ephemeris as observations, construct the observation error equation, and use the least squares estimation method to obtain the correction values ​​of the satellite initial state parameters, the correction values ​​of the perturbation model parameters, and the observation residuals. S205. Detect cycle slips and gross errors using residual editing method, and update the data quality log file; S206, iterative steps S202-S205, until the parameters converge to the target threshold to obtain the refined trajectory.

4. The method for calibrating the deviation between mixed signals and pilot signals in a navigation satellite system according to claim 3, characterized in that, The raw pseudorange and raw carrier phase observations in S3 include: IGS monitoring station m and IGS test station n The station received navigation satellites s frequency ,frequency Mixed signals x and pilot signal p The original pseudorange observations; IGS monitoring station m and IGS test station n The station received navigation satellites s frequency ,frequency Mixed signals x and pilot signal p The original carrier phase observations.

5. The method for calibrating the deviation between mixed signals and pilot signals in a navigation satellite system according to claim 4, characterized in that, The specific details of obtaining the intra-symbol bias of the non-ionospheric combination frequency through parameter estimation in S3 include: S301. The first-order ionospheric delay is eliminated by applying the ionospheric combination to the original pseudorange observations and the original carrier phase observations respectively, resulting in the ionospheric combination equation. S302. Reorganize the ionosphere-free combinatorial equations to eliminate rank deficiency and obtain the standard ionosphere-free combinatorial equations. The intra-frequency code deviation of the ionosphere-free combination is obtained by solving the standard ionosphere-free combination equation.

6. The method for calibrating the deviation between mixed signals and pilot signals in a navigation satellite system according to claim 5, characterized in that, The expression for the original pseudorange observation is: ； in, and Represent m and n The station received the S navigation satellite frequency. ,frequency pilot signal on p and mixed signals x pseudorange observations; The expression for the original carrier phase observation is: ； in, and They are respectively m and n The station received s Navigation satellite frequencies ,frequency pilot signal on p and mixed signals x Carrier phase observations, for s and receiver m , n Geometric distance between them and for m , n Receiver clock bias For satellite s The clock difference, and For satellite s and receiver m , n The tropospheric delay between them At the speed of light, and For satellite s and receiver m , n The first-order ionospheric delay between them, For frequency and frequency ratio, and for m and n The signal received by the station s Navigation satellite frequencies ,frequency pilot signal on p and mixed signals x Integer blur, They are respectively s Navigation satellite frequencies and frequency wavelength, and for m and n measuring station s Navigation satellite frequencies ,frequency pilot signal on p and mixed signals x pseudorange hardware delay, and For navigation satellites s In frequency ,frequency pilot signal on p and mixed signals x pseudorange hardware delay, and for m and n Stations on navigation satellites s frequency ,frequency pilot signal on p and mixed signals x Phase hardware delay, For satellite s In frequency ,frequency Phase hardware delay on, and For satellite s and receiver m , n Between in frequency and frequency pseudorange noise on and For satellite s and receiver m , n Between in frequency and frequency Phase noise on the surface.

7. The method for calibrating the deviation between mixed signals and pilot signals in a navigation satellite system according to claim 6, characterized in that, In S302, the original pseudorange observations and the original carrier phase observations are respectively processed using an ionospheric-free combination to eliminate the first-order ionospheric delay, resulting in the following expression for the ionospheric-free combination equation: ； in: ； in, , , and They are respectively m and n The station received s Navigation satellite frequencies ,frequency pilot signal on p and mixed signals x The combination of pseudorange observations and phase observations without an ionosphere; and for m and n measuring station s Navigation satellite frequencies ,frequency pilot signal on p and mixed signals x The ionosphere-free combination of pseudorange hardware delay and carrier phase hardware delay; for s Navigation satellite frequencies ,frequency pilot signal on p The pseudorange delay of the ionosphere-free combination, for s Navigation satellite frequencies ,frequency Phase-delayed, ionosphere-free combination; for s Navigation satellite frequencies ,frequency pilot signal on p and mixed signals x Integer ambiguity of ionosphere-free composites for s Navigation satellite frequencies ,frequency Intra-frequency inter-symbol deviation; This refers to the inter-symbol deviation within the ionospheric combination frequency.

8. The method for calibrating the deviation between mixed signals and pilot signals in a navigation satellite system according to claim 7, characterized in that, In S303, the expression for the standard ionosphere-free combined intra-frequency code deviation equation is obtained by recombining and eliminating the rank deficiency of the ionosphere-free combined equation: ； in: ； in, for s The satellite's IGS traditional satellite clock bias, and For the corresponding m and n Receiver clock bias and They are respectively s Navigation satellite frequencies ,frequency pilot signal on p and mixed signals x The floating-point ionosphere-free combination integer ambiguity.

9. A method for calibrating the deviation between mixed signals and pilot signals in a navigation satellite system according to claim 1, characterized in that, The specific details of the wide-lane UPD obtained in S4 through MW combination for navigation satellite pilot signals and hybrid signals are as follows: S401. By using MW combination to form the wide-lane ambiguity of the mixed signal and pilot signal and the wide-lane UPD, the fractional part can be obtained by rounding and separation, namely the receiver and satellite wide-lane UPD. S402, using inter-satellite single difference to eliminate m and n The receiver's wide-lane UPD is used to obtain the inter-satellite single-difference wide-lane UPD; S403. Combining the constraint that the mean UPD of all satellite wide lanes is zero, the wide lane UPD of each satellite is obtained by using the least squares estimation method.

10. A method for calibrating the deviation between mixed signals and pilot signals in a navigation satellite system according to claim 1, characterized in that, In S5, the wide-lane UPD difference between navigation satellite pilot signals and mixed signals is determined based on the principle of minimizing the L1 norm of the wide-lane UPD difference. The specific content of the intra-frequency inter-symbol error at a single frequency is obtained by jointly solving the intra-frequency inter-symbol error of the non-ionospheric combination: The mixed signal and pilot signal will generate two sets of wide-lane UPDs. Subtracting the two sets of wide-lane UPDs yields the expression for the subtraction of the two sets of wide-lane UPDs: ； In the two sets of wide lane UPD subtraction expressions For unknown constants, adjustment constants C This minimizes the L1 norm of the wide-lane UPD difference between the satellite mixed signal and the pilot signal, as detailed below: ； in To account for the difference in wide-lane UPD between mixed signal and pilot signal, the following is used: Differences between the two wide lane UPDs Jointly solve for frequency and frequency Intra-frequency inter-symbol deviation and : ； in, The wavelength is for the narrow alleyway.

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