Navigation satellite pseudo-range deviation correction method based on geometric-free combination and ionospheric-free combination

Abstract

The invention provides a navigation satellite pseudo-range deviation correction method based on non-geometric combination and non-ionospheric combination. The method comprises the following steps: constructing a non-geometric combination observation equation of a reference station receiver to a navigation satellite; solving an inter-symbol deviation (DCB) parameter between a reference station receiver and a navigation satellite; obtaining a difference between pseudo-range deviations of the two frequency points by subtracting a navigation satellite DCB parameter issued by an IGS analysis center; the method comprises the following steps of: carrying out PPP (Point-to-Point Protocol) calculation by using double-frequency observation data of a reference station receiver and a navigation satellite precision orbit clock error product issued by an IGS (Inertial Gain System) analysis center, and extracting a pseudo-range deviation ionosphere-free combination of two frequency points from a pseudo-range residual error; determining the pseudo-range deviation of each frequency point by combining the difference of the pseudo-range deviations of the two frequency points and the non-ionized layer combination of the pseudo-range deviations of the two frequency points; and correcting the pseudo-range deviation in the navigation satellite observation data of the reference station receiver according to the pseudo-range deviation of each frequency point of the reference station receiver. According to the invention, pseudo-range deviation correction of the pseudo-range observation value of the corresponding frequency point of the receiver can be realized, and the positioning performance is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of satellite navigation, and relates to a navigation satellite pseudo-range deviation correction method based on geometry-free combination and ionosphere-free combination. Background Art

[0002] The data processing of satellite navigation positioning uses pseudorange as the main observation. Therefore, the quality of pseudorange observation has a very important impact on the positioning performance of single-frequency and dual-frequency satellite navigation users. The more typical error sources in pseudorange observations, including multipath effects, measurement noise, differential code bias (DCB), etc., have been correctly recognized and properly handled, and their impact on satellite navigation data processing has also been well suppressed. In addition to the above error sources, pseudorange bias, which has been paid attention to by domestic scholars in recent years, is another important error source in pseudorange observations.

[0003] Due to the non-ideal characteristics of navigation satellite payloads and transmitting devices, downlink satellite navigation signals are distorted to varying degrees. Different types or manufacturers of receivers have different parameters such as front-end bandwidth or correlator spacing, resulting in inconsistent processing results for the same distorted signal by different receivers, resulting in pseudo-range measurement constant deviations of different magnitudes and signs. This constant deviation is called pseudo-range deviation. Due to the different degrees of distortion of different satellite navigation signals, the parameter settings of receivers from different manufacturers or models may also be different. Therefore, for a specific navigation signal, the same receiver has different pseudo-range deviations for different satellites, and receivers with different parameter settings have different pseudo-range deviations for the same satellite. The above characteristics of pseudo-range deviations make it impossible to be absorbed by satellite clock error parameters, receiver clock error parameters, and DCB parameters in the generation of satellite navigation data products and user positioning solutions, which has an adverse effect on satellite navigation positioning performance.

[0004] With the continuous improvement of the accuracy of various navigation products of satellite navigation systems, users' requirements for navigation and positioning service performance are becoming increasingly demanding, and pseudorange bias has become an error that cannot be ignored. More and more researchers are focusing on how to weaken or even eliminate the impact of pseudorange bias. Studies have shown that certain effects can be achieved by weakening pseudorange bias through three ways: adjusting the receiver loop parameters, adjusting the receiver internal algorithm, and adjusting the satellite pre-distortion filter parameters. However, if the technical status of the receiver and the satellite is not adjusted, the pseudorange bias can only be calibrated and corrected in data processing. The existing pseudorange bias calculation method is mainly based on the pseudorange bias calculation method of the OC double difference of the collocated receiver. This method can calculate the pseudorange bias of each frequency point of the navigation satellite, but it requires the collocation of two receivers (zero baseline or short baseline) as a prerequisite, so it is greatly restricted in actual data processing. Summary of the invention

[0005] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art and provide a navigation satellite pseudorange deviation correction method based on a geometry-free combination and an ionosphere-free combination, which can realize the pseudorange deviation correction of pseudorange observation values ​​of different frequency points of any reference station receiver, thereby improving the positioning performance of the reference station receiver.

[0006] The technical solution of the present invention is:

[0007] In the first aspect, a navigation satellite pseudorange deviation correction method based on a geometry-free combination and an ionosphere-free combination is proposed, comprising the following steps:

[0008] 1) Using m reference station receivers of the same model to form a regional monitoring station network, the pseudo-range observation values ​​of the two frequency points F1 and F2 of each reference station receiver are subjected to geometry-free combination data processing to construct the geometry-free combination observation equation of multiple stations and multiple satellites;

[0009] 2) Using the multi-station and multi-satellite geometry-free combined observation equation obtained in step 1), the DCB parameters of m reference station receivers and n navigation satellites are solved by least squares whole network solution;

[0010] 3) Using the DCB parameters of the n navigation satellites obtained in step 2), the DCB parameters of the corresponding navigation satellites released by the IGS analysis center are respectively subtracted to obtain the pseudorange deviation value of each navigation satellite, which is the mutual difference of the pseudorange deviation of the reference station receiver at the two frequency points F1 and F2;

[0011] 4) Using the pseudo-range observations and carrier phase observations of the two frequency points F1 and F2 of each reference station receiver, the precise orbit and clock products of the navigation satellite released by the IGS Analysis Center are selected to perform static precise point positioning solutions;

[0012] 5) extracting the pseudorange deviation of each navigation satellite from the pseudorange residuals of the static precise point positioning solution of each reference station receiver obtained in step 4), and obtaining the final pseudorange deviation value of each navigation satellite by taking the average value of the pseudorange deviations of multiple station receivers, which is the dual-frequency ionosphere-free combination value of the pseudorange deviations of the reference station receiver at the two frequency points F1 and F2;

[0013] 6) Take the mutual difference of the pseudorange deviations of each navigation satellite at the two frequency points F1 and F2 obtained in step 3), take the dual-frequency ionosphere-free combination of the pseudorange deviations of each navigation satellite at the two frequency points F1 and F2 obtained in step 5), combine the two, and solve the pseudorange deviation value of the F1 frequency point and the pseudorange deviation value of the F2 frequency point of each navigation satellite;

[0014] 7) During the positioning processing of the reference station receiver, the pseudorange deviation is corrected according to the observation value frequency point used for positioning using the pseudorange deviation value of the corresponding frequency point obtained in step 6), so as to improve the positioning performance of the reference station receiver.

[0015] Furthermore, the step 1) constructs the geometry-free combined observation equation of multiple stations and multiple satellites, for reference station receiver i and navigation satellite j, specifically:

[0016] The difference between the pseudorange observation values ​​of the two frequency points F1 and F2 is used to obtain the sum of the ionospheric delay difference between the two frequency points F1 and F2, the receiver code deviation and the navigation satellite code deviation, as follows:

[0017]

[0018] Where: ΔP F1-F2 is the difference between the pseudorange observation values ​​of the two frequency points F1 and F2, ΔIONO F1-F2 is the ionospheric delay difference between the two frequencies F1 and F2, and are the inter-code biases of reference station receiver i and navigation satellite j respectively; due to ΔIONO F1-F2 The global ionospheric electron content map provided by the IGS Analysis Center is used to calculate the above equation:

[0019]

[0020] in, is the difference in pseudorange observation values ​​after deducting the influence of the ionosphere; the above formula is the geometry-free combined observation equation of reference station receiver i to navigation satellite j. The same method is used to construct the multi-station and multi-satellite geometry-free combined observation equations of all reference station receivers to all navigation satellites.

[0021] Furthermore, the pseudorange deviation value of each navigation satellite is obtained in step 3), specifically:

[0022] Subtract the DCB parameters of the n navigation satellites obtained in step 2) from the DCB parameters of the corresponding navigation satellites released by the IGS Analysis Center. For reference station receiver i and navigation satellite j, the details are as follows:

[0023]

[0024] in, is the code deviation parameter between F1 and F2 frequency points of navigation satellite j released by the IGS Analysis Center, and are the pseudorange deviations of navigation satellite j at the F1 and F2 frequencies respectively.

[0025] Furthermore, the static precise single point positioning solution described in step 4) is specifically:

[0026] 41) The pseudorange observation values ​​and carrier phase observation values ​​of the two frequency points F1 and F2 of the reference station receiver are respectively combined into a dual-frequency ionosphere-free combination. For reference station receiver i and navigation satellite j, the specific details are as follows:

[0027] P IF =ρ-c·δt i +c·δt j +Δtrop+Δecc+Δpco+Δrel+Δgtide+Δmultipath+ε code

[0028] L IF =ρ-c·δt i +c·δt j +Δtrop+Δecc+Δpco+Δrel+Δgtide+Δwindup-λN+ε phs

[0029] Where: ρ is the geometric distance between the satellite and the receiver. The satellite position is calculated based on the precise orbit of the navigation satellite released by the IGS Analysis Center; c is the speed of light, δt i and δt j are the reference station receiver i clock error and navigation satellite j clock error respectively. The navigation satellite clock error is calculated based on the navigation satellite precise clock error released by the IGS Analysis Center. Δtrop is the tropospheric delay, Δecc is the station eccentricity effect, Δpco is the satellite antenna phase center effect, Δrel is the relativistic effect, Δgtide is the station tidal correction, and Δwindup is the satellite antenna phase winding effect. All the effects are calculated by the model. λ is the dual-frequency ionosphere-free combination wavelength. N is the dual-frequency ionosphere-free combination carrier phase ambiguity. Δmultipath is the pseudorange multipath effect. ε code and ε phs are the observation noise of pseudorange and carrier phase respectively; P IF and L IF are the pseudorange and carrier phase observations after dual-frequency ionosphere-free combination, and:

[0030]

[0031] f 1 and f 2 are the frequencies of F1 and F2 respectively, P 1 and P 2 are the pseudo-range observation values ​​of the F1 and F2 frequency points, L 1 and L 2 They are the carrier phase observation values ​​of F1 and F2 frequency points respectively;

[0032] 42) Based on the dual-frequency ionosphere-free combined observation data of each reference station receiver obtained in step 41), a static precise single-point positioning solution is performed, and the parameters to be estimated include: the position coordinates of each reference station receiver, the clock error of each reference station receiver, the zenith tropospheric delay residual of each reference station receiver, and the carrier phase ambiguity parameter.

[0033] Furthermore, in step 5), the final pseudorange deviation value of each navigation satellite is obtained by averaging the pseudorange deviations of multiple station receivers, specifically:

[0034] 51) From the pseudo-range residuals of the static precise point positioning solution of each reference station receiver obtained in step 4), the pseudo-range deviation of each navigation satellite is extracted by solving the mean value. For reference station receiver i and navigation satellite j, the specific results are as follows:

[0035]

[0036] in: is the pseudorange residual of reference station receiver i to navigation satellite j at the tth epoch, k is the total number of epochs, The pseudorange bias value of navigation satellite j calculated for reference station receiver i;

[0037] 52) The final pseudorange deviation value of each navigation satellite is obtained by averaging the pseudorange deviations of multiple reference station receivers. For navigation satellite j, the specific value is as follows:

[0038]

[0039] Where: m is the total number of reference station receivers, It is the final dual-frequency ionosphere-free combination value of the pseudorange deviation of the two frequency points F1 and F2.

[0040] Further, the step 6) of solving the pseudorange deviation value of the F1 frequency point and the pseudorange deviation value of the F2 frequency point of each navigation satellite is specifically:

[0041] 61) Take the pseudo-range deviations of each navigation satellite at the two frequency points F1 and F2 obtained in step 3), and for navigation satellite j, the specific difference is as follows:

[0042]

[0043] in: is the code deviation of navigation satellite j obtained in step 2), is the code deviation parameter between F1 and F2 frequency points of navigation satellite j released by the IGS Analysis Center, and are the pseudorange deviations of navigation satellite j at the F1 and F2 frequencies respectively;

[0044] 62) Take the pseudorange deviation dual-frequency ionosphere-free combination of each navigation satellite at the two frequency points F1 and F2 obtained in step 5), for navigation satellite j, as follows:

[0045]

[0046] in: is the dual-frequency ionosphere-free combination value of the pseudorange deviations of the two frequency points F1 and F2 obtained in step 52); 1 and f 2 are the frequencies of F1 and F2 frequency points respectively;

[0047] 63) The two equations of step 61) and step 62) are combined to solve the pseudorange deviation of the F1 frequency point and the pseudorange deviation of the F2 frequency point of each navigation satellite.

[0048] Furthermore, step 7) is to improve the positioning performance of the reference station receiver, specifically:

[0049] 71) When the reference station receiver performs single-frequency positioning processing at the F1 frequency point or the F2 frequency point, the pseudorange deviation value of the F1 frequency point or the pseudorange deviation value of the F2 frequency point of each navigation satellite obtained in step 63) is deducted from the pseudorange observation value of the F1 frequency point or the pseudorange deviation value of the F2 frequency point of each navigation satellite obtained in step 63), so as to correct the pseudorange deviation of the navigation satellite and improve the single-frequency positioning performance;

[0050] 72) When the reference station receiver processes the F1 / F2 dual-frequency combination positioning, the pseudo-range deviation value of the F1 frequency point and the pseudo-range deviation value of the F2 frequency point of each navigation satellite obtained in step 63) are deducted from the pseudo-range observation values ​​of the F1 frequency point and the F2 frequency point of the corresponding navigation satellite, so as to correct the pseudo-range deviation of the navigation satellite and improve the dual-frequency positioning performance.

[0051] In a second aspect, a computer-readable storage medium is proposed, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the navigation satellite pseudorange deviation correction method based on a geometry-free combination and an ionosphere-free combination are implemented.

[0052] In the third aspect, an electronic device is proposed, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the navigation satellite pseudorange deviation correction method based on a geometry-free combination and an ionosphere-free combination when executing the computer program.

[0053] In a fourth aspect, a computer program product is proposed, comprising a computer program, which, when executed by a processor, implements the steps of the navigation satellite pseudorange deviation correction method based on geometry-free combination and ionosphere-free combination.

[0054] The advantages of the present invention compared with the prior art are:

[0055] The existing pseudorange deviation calculation method is mainly based on the pseudorange deviation calculation method of collocated receivers. Although this method can calculate the pseudorange deviation of each frequency point of the navigation satellite, it requires the collocation of two receivers (zero baseline or short baseline) as a prerequisite. The present invention proposes a navigation satellite pseudorange deviation correction method based on geometry-free combination and ionosphere-free combination, which jointly uses the geometry-free combination and ionosphere-free combination of pseudorange observation values ​​of different frequency points, solves the problem of high-precision calculation of pseudorange deviation without relying on collocated receivers, and improves the positioning performance of the reference station receiver by directly correcting the pseudorange deviation of the corresponding frequency point on the pseudorange observation value. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 The figure is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0057] The present invention is based on a navigation satellite pseudorange deviation correction method without geometry combination and ionosphere combination, such as Figure 1 As shown, the following steps are included:

[0058] 1) Using m reference station receivers of the same model to form a regional monitoring station network, the pseudo-range observation values ​​of the two frequency points F1 and F2 of each reference station receiver are subjected to geometry-free combination data processing to construct the geometry-free combination observation equation of multiple stations and multiple satellites;

[0059] 2) Using the multi-station and multi-satellite geometry-free combined observation equation obtained in step 1), the DCB parameters of m reference station receivers and n navigation satellites are solved by least squares whole network solution;

[0060] 3) Using the DCB parameters of the n navigation satellites obtained in step 2), the DCB parameters of the corresponding navigation satellites released by the IGS analysis center are respectively subtracted to obtain the pseudorange deviation value of each navigation satellite, which is the mutual difference of the pseudorange deviation of the reference station receiver at the two frequency points F1 and F2;

[0061] 4) Using the pseudo-range observations and carrier phase observations of the two frequency points F1 and F2 of each reference station receiver, the precise orbit and clock products of the navigation satellite released by the IGS Analysis Center are selected to perform static precise point positioning (PPP) solution;

[0062] 5) extracting the pseudorange bias of each navigation satellite from the pseudorange residuals solved by PPP of each reference station receiver obtained in step 4), and obtaining the final pseudorange bias value of each navigation satellite by averaging the pseudorange biases of multiple station receivers, which is a dual-frequency ionosphere-free combination value of the pseudorange bias of the reference station receiver at the two frequency points F1 and F2;

[0063] 6) Take the mutual difference of the pseudorange deviations of each navigation satellite at the two frequency points F1 and F2 obtained in step 3), take the dual-frequency ionosphere-free combination of the pseudorange deviations of each navigation satellite at the two frequency points F1 and F2 obtained in step 5), combine the two, and solve the pseudorange deviation value of the F1 frequency point and the pseudorange deviation value of the F2 frequency point of each navigation satellite;

[0064] 7) During the positioning processing of the reference station receiver, the pseudorange deviation is corrected according to the observation value frequency point used for positioning using the pseudorange deviation value of the corresponding frequency point obtained in step 6), so as to improve the positioning performance of the reference station receiver.

[0065] The method of constructing the geometry-free combined observation equation of multiple stations and multiple satellites in step 1) is specifically as follows, taking reference station receiver i and navigation satellite j as an example:

[0066] The difference between the pseudorange observation values ​​of the two frequency points F1 and F2 is used to obtain the sum of the ionospheric delay difference between the two frequency points F1 and F2, the receiver code deviation and the navigation satellite code deviation, as follows:

[0067]

[0068] Where: ΔP F1-F2 is the difference between the pseudorange observation values ​​of the two frequency points F1 and F2, ΔIONO F1-F2 is the ionospheric delay difference between the two frequencies F1 and F2, and are the inter-code deviations of reference station receiver i and navigation satellite j respectively. F1-F2 It can be calculated using the Global Ionospheric Map (GIM) provided by the IGS Analysis Center, so the above formula can be written as:

[0069]

[0070] in, is the difference of pseudo-range observation values ​​after deducting the influence of ionosphere. The above formula is the geometry-free combination observation equation of reference station receiver i to navigation satellite j. Similarly, the geometry-free combination observation equation of multi-station and multi-satellite for all reference station receivers to all navigation satellites can be constructed.

[0071] The step 3) obtains the pseudorange deviation value of each navigation satellite, specifically:

[0072] The DCB parameters of the n navigation satellites obtained in step 2) are respectively subtracted from the DCB parameters of the corresponding navigation satellites released by the IGS analysis center. Taking reference station receiver i and navigation satellite j as an example, the details are as follows:

[0073]

[0074] in, is the code deviation parameter between F1 and F2 frequency points of navigation satellite j released by the IGS Analysis Center, and are the pseudorange deviations of navigation satellite j at the F1 and F2 frequencies respectively.

[0075] The step 4) performs static PPP solution, specifically:

[0076] 41) The pseudo-range observation values ​​and carrier phase observation values ​​of the two frequency points F1 and F2 of the reference station receiver are respectively combined into a dual-frequency ionosphere-free combination. Taking reference station receiver i and navigation satellite j as an example, the details are as follows:

[0077] P IF =ρ-c·δt i +c·δt j +Δtrop+Δecc+Δpco+Δrel+Δgtide+Δmultipath+ε code

[0078] L IF =ρ-c·δt i +c·δt j +Δtrop+Δecc+Δpco+Δrel+Δgtide+Δwindup-λN+ε phs

[0079] Where: ρ is the geometric distance between the satellite and the receiver. The satellite position can be calculated based on the precise orbit of the navigation satellite released by the IGS Analysis Center; c is the speed of light, δt i and δt j are the reference station receiver i clock error and navigation satellite j clock error respectively. The navigation satellite clock error can be calculated based on the navigation satellite precise clock error released by the IGS Analysis Center; Δtrop is the tropospheric delay, Δecc is the station eccentricity effect (receiver antenna phase center), Δpco is the satellite antenna phase center effect, Δrel is the relativistic effect, Δgtide is the station tidal correction, Δwindup is the satellite antenna phase winding effect, and all the effects are calculated by the model; λ is the dual-frequency ionosphere-free combination wavelength; N is the dual-frequency ionosphere-free combination carrier phase ambiguity; Δmultipath is the pseudorange multipath effect; ε code and ε phsare the observation noise of pseudorange and carrier phase respectively; P IF and L IF are the pseudorange and carrier phase observations after dual-frequency ionosphere-free combination, and:

[0080]

[0081] f 1 and f 2 are the frequencies of F1 and F2 respectively, P 1 and P 2 are the pseudo-range observation values ​​of the F1 and F2 frequency points, L 1 and L 2 They are the carrier phase observation values ​​of F1 and F2 frequency points respectively.

[0082] 42) Based on the dual-frequency ionosphere-free combined observation data of each reference station receiver obtained in step 41), a static PPP solution is performed, and the parameters to be estimated include: the position coordinates of each reference station receiver, the clock error of each reference station receiver, the zenith tropospheric delay residual of each reference station receiver, and the carrier phase ambiguity parameters.

[0083] The step 5) obtains the final pseudorange deviation value of each navigation satellite by taking the average value of the pseudorange deviations of multiple station receivers, specifically:

[0084] 51) From the pseudo-range residuals of the static PPP solution of each reference station receiver obtained in step 4), the pseudo-range bias of each navigation satellite is extracted by solving the mean value. Taking reference station receiver i and navigation satellite j as an example, the specific details are as follows:

[0085]

[0086] in: is the pseudorange residual of reference station receiver i to navigation satellite j at the tth epoch, k is the total number of epochs, Pseudorange bias value of navigation satellite j calculated for reference station receiver i.

[0087] 52) The final pseudorange deviation value of each navigation satellite is obtained by taking the average value of the pseudorange deviations of multiple reference station receivers. Taking navigation satellite j as an example, the specific value is as follows:

[0088]

[0089] Where: m is the total number of reference station receivers, It is the final dual-frequency ionosphere-free combination value of the pseudorange deviation of the two frequency points F1 and F2.

[0090] The step 6) solves the pseudorange deviation value of the F1 frequency point and the pseudorange deviation value of the F2 frequency point of each navigation satellite, specifically:

[0091] 61) Take the pseudo-range deviations of each navigation satellite at the two frequency points F1 and F2 obtained in step 3), and take navigation satellite j as an example, the specific difference is as follows:

[0092]

[0093] in: is the code deviation of navigation satellite j obtained in step 2), is the code deviation parameter between F1 and F2 frequency points of navigation satellite j released by the IGS Analysis Center, and are the pseudorange deviations of navigation satellite j at the F1 and F2 frequencies respectively.

[0094] 62) Take the pseudorange deviation dual-frequency ionosphere-free combination of each navigation satellite at the two frequency points F1 and F2 obtained in step 5), taking navigation satellite j as an example, the details are as follows:

[0095]

[0096] in: is the dual-frequency ionosphere-free combination value of the pseudorange deviations of the two frequency points F1 and F2 obtained in step 52); 1 and f 2 They are the frequencies of F1 and F2 respectively.

[0097] 63) The two equations of step 61) and step 62) are combined to solve the pseudorange deviation of the F1 frequency point and the pseudorange deviation of the F2 frequency point of each navigation satellite.

[0098] The step 7) improves the positioning performance of the reference station receiver, specifically:

[0099] 71) When the reference station receiver performs single-frequency positioning processing at the F1 frequency point or the F2 frequency point, the pseudorange deviation value of the F1 frequency point or the pseudorange deviation value of the F2 frequency point of each navigation satellite obtained in step 63) is deducted from the pseudorange observation value of the F1 frequency point or the pseudorange deviation value of the F2 frequency point of each navigation satellite obtained in step 63), so as to correct the pseudorange deviation of the navigation satellite and improve the single-frequency positioning performance.

[0100] 72) When the reference station receiver processes the F1 / F2 dual-frequency combination positioning, the pseudo-range deviation value of the F1 frequency point and the pseudo-range deviation value of the F2 frequency point of each navigation satellite obtained in step 63) are deducted from the pseudo-range observation values ​​of the F1 frequency point and the F2 frequency point of the corresponding navigation satellite, so as to correct the pseudo-range deviation of the navigation satellite and improve the dual-frequency positioning performance.

[0101] The present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and when the computer instructions are executed on a computer, the computer executes Figure 1 The method described.

[0102] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) that contain computer-usable program code.

[0103] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0104] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0105] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0106] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

[0107] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A navigation satellite pseudorange deviation correction method based on geometry-free combination and ionosphere-free combination, characterized in that: The following steps are involved: 1) Using m reference station receivers of the same model to form a regional monitoring station network, the pseudo-range observation values ​​of the two frequency points F1 and F2 of each reference station receiver are subjected to geometry-free combination data processing to construct the geometry-free combination observation equation of multiple stations and multiple satellites; 2) Using the multi-station and multi-satellite geometry-free combined observation equation obtained in step 1), the DCB parameters of m reference station receivers and n navigation satellites are solved by least squares whole network solution; 3) Using the DCB parameters of the n navigation satellites obtained in step 2), the DCB parameters of the corresponding navigation satellites released by the IGS analysis center are respectively subtracted to obtain the pseudorange deviation value of each navigation satellite, which is the mutual difference of the pseudorange deviation of the reference station receiver at the two frequency points F1 and F2; 4) Using the pseudo-range observations and carrier phase observations of the two frequency points F1 and F2 of each reference station receiver, the precise orbit and clock products of the navigation satellite released by the IGS Analysis Center are selected to perform static precise point positioning solutions; 5) extracting the pseudorange deviation of each navigation satellite from the pseudorange residuals of the static precise point positioning solution of each reference station receiver obtained in step 4), and obtaining the final pseudorange deviation value of each navigation satellite by taking the average value of the pseudorange deviations of multiple station receivers, which is the dual-frequency ionosphere-free combination value of the pseudorange deviations of the reference station receiver at the two frequency points F1 and F2; 6) Take the mutual difference of the pseudorange deviations of each navigation satellite at the two frequency points F1 and F2 obtained in step 3), take the dual-frequency ionosphere-free combination of the pseudorange deviations of each navigation satellite at the two frequency points F1 and F2 obtained in step 5), combine the two, and solve the pseudorange deviation value of the F1 frequency point and the pseudorange deviation value of the F2 frequency point of each navigation satellite; 7) During the positioning processing of the reference station receiver, the pseudorange deviation is corrected according to the observation value frequency point used for positioning using the pseudorange deviation value of the corresponding frequency point obtained in step 6), so as to improve the positioning performance of the reference station receiver.

2. The navigation satellite pseudorange deviation correction method based on geometry-free combination and ionosphere-free combination according to claim 1 is characterized in that: Step 1) constructs the geometry-free combined observation equation for multiple stations and multiple satellites. For reference station receiver i and navigation satellite j, it is specifically: The difference between the pseudorange observation values ​​of the two frequency points F1 and F2 is used to obtain the sum of the ionospheric delay difference between the two frequency points F1 and F2, the receiver code deviation and the navigation satellite code deviation, as follows: Where: ΔP F1-F2 is the difference between the pseudorange observation values ​​of the two frequency points F1 and F2, ΔIONO F1-F2 is the ionospheric delay difference between the two frequencies F1 and F2, and are the inter-code biases of reference station receiver i and navigation satellite j respectively; due to ΔIONO F1-F2 The global ionospheric electron content map provided by the IGS Analysis Center is used to calculate the above equation: in, is the difference in pseudorange observation values ​​after deducting the influence of the ionosphere; the above formula is the geometry-free combined observation equation of reference station receiver i to navigation satellite j. The same method is used to construct the multi-station and multi-satellite geometry-free combined observation equations of all reference station receivers to all navigation satellites.

3. The navigation satellite pseudorange deviation correction method based on geometry-free combination and ionosphere-free combination according to claim 2 is characterized in that: Step 3) obtains the pseudorange deviation value of each navigation satellite, specifically: Subtract the DCB parameters of the n navigation satellites obtained in step 2) from the DCB parameters of the corresponding navigation satellites released by the IGS Analysis Center. For reference station receiver i and navigation satellite j, the details are as follows: in, is the code deviation parameter between F1 and F2 frequency points of navigation satellite j released by the IGS Analysis Center, and are the pseudorange deviations of navigation satellite j at the F1 and F2 frequencies respectively.

4. The navigation satellite pseudorange deviation correction method based on geometry-free combination and ionosphere-free combination according to claim 3 is characterized in that: Step 4) performs static precise single-point positioning solution, specifically: 41) The pseudorange observation values ​​and carrier phase observation values ​​of the two frequency points F1 and F2 of the reference station receiver are respectively combined into a dual-frequency ionosphere-free combination. For reference station receiver i and navigation satellite j, the specific details are as follows: P IF =ρ-c·δt i +c·δt j +Δtrop+Δdecc+Δpco+Δrel+Δgtide+Δmultipath+e code L IF =ρ-c·δt i +c·δt j +Δtrop+Δecc+Δpco+Δrel+Δgtide+Δwindup-λN+ε phs Where: ρ is the geometric distance between the satellite and the receiver. The satellite position is calculated based on the precise orbit of the navigation satellite released by the IGS Analysis Center; c is the speed of light, and δt j are the reference station receiver i clock error and navigation satellite j clock error respectively. The navigation satellite clock error is calculated based on the navigation satellite precise clock error released by the IGS Analysis Center. Δtrop is the tropospheric delay, Δecc is the station eccentricity effect, Δpco is the satellite antenna phase center effect, Δrel is the relativistic effect, Δgtide is the station tidal correction, and Δwindup is the satellite antenna phase winding effect. All the effects are calculated by the model. λ is the dual-frequency ionosphere-free combination wavelength. N is the dual-frequency ionosphere-free combination carrier phase ambiguity. Δmultipath is the pseudorange multipath effect. ε code and ε phs are the observation noise of pseudorange and carrier phase respectively; P IF and L IF are the pseudorange and carrier phase observations after dual-frequency ionosphere-free combination, and: f1 and f2 are the frequencies of F1 and F2 respectively, P1 and P2 are the pseudorange observation values ​​of F1 and F2 respectively, L1 and L2 are the carrier phase observation values ​​of F1 and F2 respectively; 42) Based on the dual-frequency ionosphere-free combined observation data of each reference station receiver obtained in step 41), a static precise single-point positioning solution is performed, and the parameters to be estimated include: the position coordinates of each reference station receiver, the clock error of each reference station receiver, the zenith tropospheric delay residual of each reference station receiver, and the carrier phase ambiguity parameter.

5. The navigation satellite pseudorange deviation correction method based on geometry-free combination and ionosphere-free combination according to claim 4 is characterized in that: Step 5) obtains the final pseudorange deviation value of each navigation satellite by averaging the pseudorange deviations of multiple station receivers, specifically: 51) From the pseudo-range residuals of the static precise point positioning solution of each reference station receiver obtained in step 4), the pseudo-range deviation of each navigation satellite is extracted by solving the mean value. For reference station receiver i and navigation satellite j, the specific results are as follows: in: is the pseudorange residual of reference station receiver i to navigation satellite j at the tth epoch, k is the total number of epochs, The pseudorange bias value of navigation satellite j calculated for reference station receiver i; 52) The final pseudorange deviation value of each navigation satellite is obtained by averaging the pseudorange deviations of multiple reference station receivers. For navigation satellite j, the specific value is as follows: Where: m is the total number of reference station receivers, is the final dual-frequency ionosphere-free combination value of the pseudorange deviation of the two frequency points F1 and F2.

6. The navigation satellite pseudorange deviation correction method based on geometry-free combination and ionosphere-free combination according to claim 5, characterized in that: Step 6) is to solve the pseudorange deviation value of each navigation satellite F1 frequency point and the pseudorange deviation value of the F2 frequency point, specifically: 61) Take the pseudo-range deviations of each navigation satellite at the two frequency points F1 and F2 obtained in step 3), and for navigation satellite j, the specific difference is as follows: in: is the code deviation of navigation satellite j obtained in step 2), is the code deviation parameter between F1 and F2 frequency points of navigation satellite j released by the IGS Analysis Center, and are the pseudorange deviations of navigation satellite j at the F1 and F2 frequencies respectively; 62) Take the pseudorange deviation dual-frequency ionosphere-free combination of each navigation satellite at the two frequency points F1 and F2 obtained in step 5), for navigation satellite j, as follows: in: is the dual-frequency ionosphere-free combination value of the pseudorange deviations of the two frequency points F1 and F2 obtained in step 52); f1 and f2 are the frequencies of the frequency points F1 and F2 respectively; 63) The two equations of step 61) and step 62) are combined to solve the pseudorange deviation of the F1 frequency point and the pseudorange deviation of the F2 frequency point of each navigation satellite.

7. The navigation satellite pseudorange deviation correction method based on geometry-free combination and ionosphere-free combination according to claim 6 is characterized in that: Step 7) achieves the improvement of the positioning performance of the reference station receiver, specifically: 71) When the reference station receiver performs single-frequency positioning processing at the F1 frequency point or the F2 frequency point, the pseudorange deviation value of the F1 frequency point or the pseudorange deviation value of the F2 frequency point of each navigation satellite obtained in step 63) is deducted from the pseudorange observation value of the F1 frequency point or the pseudorange deviation value of the F2 frequency point of each navigation satellite obtained in step 63), so as to correct the pseudorange deviation of the navigation satellite and improve the single-frequency positioning performance; 72) When the reference station receiver processes the F1 / F2 dual-frequency combination positioning, the pseudo-range deviation value of the F1 frequency point and the pseudo-range deviation value of the F2 frequency point of each navigation satellite obtained in step 63) are deducted from the pseudo-range observation values ​​of the F1 frequency point and the F2 frequency point of the corresponding navigation satellite, so as to correct the pseudo-range deviation of the navigation satellite and improve the dual-frequency positioning performance.

8. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

9. 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 computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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