Navigation satellite pseudo-range bias correction method based on geometry-free combination and ionosphere-free combination

Abstract

The application proposes a navigation satellite pseudo-range deviation correction method based on non-geometric combination and ionosphere-free combination, comprising: constructing a non-geometric combination observation equation of a reference station receiver to a navigation satellite; solving a code bias between satellites DCB parameter of the reference station receiver and the navigation satellite; obtaining a difference between two frequency point pseudo-range deviations by subtracting the navigation satellite DCB parameter published by the IGS analysis center; performing PPP solving by using the double-frequency observation data of the reference station receiver and the precise orbit and clock difference product of the navigation satellite published by the IGS analysis center, and extracting the ionosphere-free combination of the two frequency point pseudo-range deviations in the pseudo-range residual; simultaneously solving the difference between the two frequency point pseudo-range deviations and the ionosphere-free combination of the two frequency point pseudo-range deviations to determine the pseudo-range deviation of each frequency point; and correcting the pseudo-range deviation in the pseudo-range observation data of the reference station receiver to the navigation satellite according to the pseudo-range deviation of each frequency point of the reference station receiver. The application can correct the pseudo-range deviation of the pseudo-range observation value of the corresponding frequency point of the receiver and improve the positioning performance.

Description

Technical Field

[0001] This invention belongs to the field of satellite navigation technology and relates to a method for correcting pseudorange deviations of navigation satellites based on the combination of geometric and ionospheric features. Background Technology

[0002] Data processing for satellite navigation and positioning relies heavily on pseudorange as the primary observation. Therefore, the quality of pseudorange observations has a significant impact on the positioning performance of both single-frequency and dual-frequency satellite navigation users. Typical error sources in pseudorange observations, including multipath effects, measurement noise, and differential code bias (DCB), have been correctly identified and properly addressed, and their impact on satellite navigation data processing has been effectively suppressed. In addition to the aforementioned error sources, pseudorange bias, which has attracted attention from 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 exhibit varying degrees of distortion. Different types or manufacturers of receivers have different front-end bandwidth or correlator spacing settings, leading to inconsistent processing results for the same distorted signal. This results in pseudorange measurement constant deviations of varying magnitudes and signs, known as pseudorange bias. Because the distortion levels of different satellite navigation signals vary, and receiver parameter settings may differ between manufacturers or models, for a specific navigation signal, the pseudorange bias of the same receiver will differ for different satellites, and receivers with different parameter settings will also have different pseudorange biases for the same satellite. These characteristics of pseudorange bias mean that it cannot be absorbed by satellite clock bias parameters, receiver clock bias parameters, and DCB parameters during satellite navigation data product generation and user positioning calculations, thus adversely affecting satellite navigation and positioning performance.

[0004] As the accuracy of various navigation products from satellite navigation systems continues to improve, users' demands for navigation and positioning service performance are becoming increasingly stringent, and pseudorange bias has become a significant error. More and more researchers are focusing on how to reduce or even eliminate the impact of pseudorange bias. Studies have shown that adjusting receiver loop parameters, internal receiver algorithms, and satellite predistortion filter parameters can effectively reduce pseudorange bias. However, without adjusting the technical specifications of the receiver and satellite, pseudorange bias can only be calibrated and corrected during data processing. Currently, existing pseudorange bias calculation methods are mainly based on the dual-difference OC method with co-located receivers. This method can calculate the pseudorange bias at various frequencies of navigation satellites, but it requires two receivers deployed in parallel (zero baseline or short baseline), thus significantly limiting its practical application in data processing. Summary of the Invention

[0005] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a pseudorange deviation correction method for navigation satellites based on the combination of geometric combination and ionosphere combination. This method can correct the pseudorange deviation of pseudorange observations at different frequency points of any reference station receiver, thereby improving the positioning performance of the reference station receiver.

[0006] The technical solution of this invention is:

[0007] Firstly, a pseudorange bias correction method for navigation satellites based on the combination of geometric and ionospheric features is proposed, including the following steps:

[0008] 1) Using m identical reference station receivers to form a regional monitoring network, perform geometrically non-combined data processing on the pseudorange observations of the two frequency points F1 and F2 of each reference station receiver to construct a geometrically non-combined observation equation for multiple stations and multiple satellites;

[0009] 2) Using the geometric-free observation equations for multiple stations and multiple satellites obtained in step 1), the DCB parameters of m reference station receivers and n navigation satellites are obtained by using the least squares whole network solution method;

[0010] 3) Using the DCB parameters of the n navigation satellites obtained in step 2), the difference is calculated with the DCB parameters of the corresponding navigation satellites released by the IGS analysis center to obtain the pseudorange deviation value of each navigation satellite. The pseudorange deviation value is the difference between the pseudorange deviations of the reference station receiver at the two frequency points F1 and F2.

[0011] 4) Using the pseudorange and carrier phase observations of the receivers at frequencies F1 and F2 of each reference station, select the precise orbit and clock error products of navigation satellites released by the IGS Analysis Center to perform static precise single-point positioning calculations;

[0012] 5) Extract the pseudorange deviation of each navigation satellite from the pseudorange residuals of the static precise single-point positioning solution of each reference station receiver obtained in step 4). Obtain the final pseudorange deviation value of each navigation satellite by averaging the pseudorange deviations of the multi-station receivers. The pseudorange deviation value is the dual-frequency non-ionospheric combination value of the pseudorange deviation of the reference station receiver at the F1 and F2 frequencies.

[0013] 6) Take the difference between the pseudorange deviations of each navigation satellite at the two frequencies F1 and F2 obtained in step 3), and take the combination of the pseudorange deviations of each navigation satellite at the two frequencies F1 and F2 obtained in step 5). Combine the two to solve for the pseudorange deviation values ​​of each navigation satellite at the F1 frequency and the F2 frequency.

[0014] 7) During the positioning process of the reference station receiver, the pseudorange deviation is corrected by using the pseudorange deviation value of the corresponding frequency point obtained in step 6) based on the observation frequency point used for positioning, thereby improving the positioning performance of the reference station receiver.

[0015] Furthermore, step 1) describes constructing the geometrically inverse observation equations for multiple stations and multiple satellites, specifically for reference station receiver i and navigation satellite j:

[0016] The pseudorange observations at frequencies F1 and F2 are subtracted to obtain the sum of the ionospheric delay difference between F1 and F2, the receiver inter-symbol bias, and the navigation satellite inter-symbol bias, as detailed below:

[0017]

[0018] Where: ΔP F1-F2 ΔIONO is the difference between the pseudorange observations at frequencies F1 and F2. F1-F2 The difference in ionospheric delay between the F1 and F2 frequency points, and These represent the inter-symbol offsets for reference station receiver i and navigation satellite j, respectively; due to ΔIONO F1-F2 The above formula is calculated using the global ionospheric electron content map provided by the IGS Analysis Center, and therefore can be written as:

[0019]

[0020] in, The difference between pseudorange observations after deducting the influence of the ionosphere is given. The above equation is the geometrically uncombined observation equation for reference station receiver i to navigation satellite j. The same method is used to construct the multi-station, multi-satellite geometrically uncombined observation equation for all reference station receivers to all navigation satellites.

[0021] Furthermore, step 3) involves obtaining the pseudorange deviation values ​​for each navigation satellite, specifically as follows:

[0022] The DCB parameters of the n navigation satellites obtained in step 2) are subtracted from the corresponding DCB parameters of the navigation satellites published by the IGS analysis center. For reference station receiver i and navigation satellite j, the specific details are as follows:

[0023]

[0024] in, This refers to the inter-symbol offset parameters of navigation satellite j between the F1 and F2 frequencies, as released by the IGS Analysis Center. and These represent the pseudorange deviations of navigation satellite j at frequencies F1 and F2, respectively.

[0025] Furthermore, step 4) involves performing static precise single-point positioning calculations, specifically as follows:

[0026] 41) The pseudorange observations and carrier phase observations at the two frequency points F1 and F2 of the reference station receiver are respectively combined into a dual-frequency ionospheric-free combination. For the reference station receiver i and the navigation satellite j, the specifics 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, and the satellite position is calculated based on the precise orbit of the navigation satellite published by the IGS Analysis Center; c is the speed of light, δt i and δt j These represent the clock bias of the reference station receiver i and the clock bias of the navigation satellite j, respectively. The navigation satellite clock bias is calculated based on the precise clock bias of navigation satellites published by the IGS Analysis Center. Δtrop is the tropospheric delay, Δecc is the effect of station eccentricity, Δpco is the effect of satellite antenna phase center, Δrel is the relativistic effect, Δgtide is the station tidal correction, and Δwindup is the effect of satellite antenna phase winding. All these effects are calculated by the model. λ is the wavelength of the dual-frequency ionosphere-free combination; N is the phase ambiguity of the dual-frequency ionosphere-free combination carrier; Δmultipath is the pseudorange multipath effect; ε code and ε phs The observation noise for pseudorange and carrier phase are respectively; P IF and L IF These are the pseudorange and carrier phase observations after the dual-frequency ionosphere-free combination, respectively, and we have:

[0030]

[0031] f1 and f2 are the frequencies of F1 and F2 respectively, P1 and P2 are the pseudorange observations of F1 and F2 respectively, and L1 and L2 are the carrier phase observations of F1 and F2 respectively.

[0032] 42) Based on the dual-frequency ionospheric-free combined observation data of each reference station receiver obtained in step 41), perform static precise single-point positioning calculation. 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, step 5) describes obtaining the final pseudorange deviation value for each navigation satellite by averaging the pseudorange deviations of the multi-station receivers, specifically as follows:

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

[0035]

[0036] in: Let k be the pseudorange residual of reference station receiver i for navigation satellite j at epoch t, ​​and k be the total number of epochs. The pseudorange deviation value of navigation satellite j calculated for reference station receiver i;

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

[0038]

[0039] Where: m is the total number of reference station receivers, This represents the final combined value of the pseudorange deviation at the two frequency points F1 and F2 without ionosphere.

[0040] Furthermore, step 6) involves calculating the pseudorange deviation values ​​at frequency F1 and frequency F2 for each navigation satellite, specifically as follows:

[0041] 61) Take the pseudorange difference between each navigation satellite at the F1 and F2 frequencies obtained in step 3). For navigation satellite j, the specific difference is as follows:

[0042]

[0043] in: The inter-code offset of navigation satellite j obtained in step 2) is... This refers to the inter-symbol offset parameters of navigation satellite j between the F1 and F2 frequencies, as released by the IGS Analysis Center. and These are the pseudorange deviations of navigation satellite j at frequencies F1 and F2, respectively.

[0044] 62) Take the pseudorange deviation dual-frequency ionospheric combination of each navigation satellite obtained in step 5) at the F1 and F2 frequencies. For navigation satellite j, the specific details are as follows:

[0045]

[0046] in: The pseudorange deviations at frequencies F1 and F2 obtained in step 52) are the combined values ​​of the two frequencies without ionosphere; f1 and f2 are the frequencies of frequencies F1 and F2, respectively.

[0047] 63) Solve the equations from steps 61) and 62) to obtain the pseudorange deviation at frequency F1 and frequency F2 of each navigation satellite.

[0048] Furthermore, step 7) describes the improvement of the reference station receiver's positioning performance, specifically as follows:

[0049] 71) During single-frequency positioning processing at the F1 or F2 frequency point of the reference station receiver, the pseudorange observation values ​​at the F1 or F2 frequency point of the corresponding navigation satellite are subtracted from the pseudorange deviation values ​​at the F1 or F2 frequency point of each navigation satellite obtained in step 63) to achieve pseudorange deviation correction of the navigation satellite and improve single-frequency positioning performance.

[0050] 72) When the reference station receiver performs F1 / F2 dual-frequency combined positioning processing, it deducts the pseudorange deviation values ​​of the F1 frequency point and the F2 frequency point of each navigation satellite obtained in step 63) from the pseudorange observation values ​​of the corresponding navigation satellites to realize pseudorange deviation correction of navigation satellites and improve dual-frequency positioning performance.

[0051] Secondly, 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, it implements the steps of the navigation satellite pseudorange deviation correction method based on geometrically uncombined and ionospherically uncombined combinations.

[0052] Thirdly, an electronic device is proposed, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the navigation satellite pseudorange deviation correction method based on the combination of geometrical and ionospheric elements.

[0053] Fourthly, a computer program product is proposed, comprising a computer program that, when executed by a processor, implements the steps of the navigation satellite pseudorange deviation correction method based on geometrically uncombined and ionospherically uncombined combinations.

[0054] The advantages of this invention compared to the prior art are:

[0055] Existing pseudorange deviation calculation methods are mainly based on parallel receivers. While these methods can calculate the pseudorange deviation at various frequencies of navigation satellites, they require two receivers to be deployed in parallel (zero baseline or short baseline). This invention proposes a navigation satellite pseudorange deviation correction method based on geometrically and ionospherically free combinations. By jointly utilizing geometrically and ionospherically free combinations of pseudorange observations at different frequencies, it solves the problem of high-precision pseudorange deviation calculation without relying on parallel receivers. By directly correcting the pseudorange deviation at the corresponding frequency based on the pseudorange observations, it improves the positioning performance of the reference station receiver. Attached Figure Description

[0056] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0057] This invention is based on a pseudorange deviation correction method for navigation satellites without geometric combinations and without ionospheric combinations, such as... Figure 1 As shown, it includes the following steps:

[0058] 1) Using m identical reference station receivers to form a regional monitoring network, perform geometrically non-combined data processing on the pseudorange observations of the two frequency points F1 and F2 of each reference station receiver to construct a geometrically non-combined observation equation for multiple stations and multiple satellites;

[0059] 2) Using the geometric-free observation equations for multiple stations and multiple satellites obtained in step 1), the DCB parameters of m reference station receivers and n navigation satellites are obtained by using the least squares whole network solution method;

[0060] 3) Using the DCB parameters of the n navigation satellites obtained in step 2), the difference is calculated with the DCB parameters of the corresponding navigation satellites released by the IGS analysis center to obtain the pseudorange deviation value of each navigation satellite. The pseudorange deviation value is the difference between the pseudorange deviations of the reference station receiver at the two frequency points F1 and F2.

[0061] 4) Using the pseudorange and carrier phase observations at the F1 and F2 frequencies of each reference station receiver, select the navigation satellite precise orbit and clock error products released by the IGS Analysis Center to perform static precise point positioning (PPP) calculation;

[0062] 5) Extract the pseudorange deviation of each navigation satellite from the pseudorange residuals of each reference station receiver obtained in step 4). Obtain the final pseudorange deviation value of each navigation satellite by averaging the pseudorange deviations of the multi-station receivers. The pseudorange deviation value is the dual-frequency non-ionospheric combination value of the pseudorange deviation of the reference station receiver at the F1 and F2 frequencies.

[0063] 6) Take the difference between the pseudorange deviations of each navigation satellite at the two frequencies F1 and F2 obtained in step 3), and take the combination of the pseudorange deviations of each navigation satellite at the two frequencies F1 and F2 obtained in step 5). Combine the two to solve for the pseudorange deviation values ​​of each navigation satellite at the F1 frequency and the F2 frequency.

[0064] 7) During the positioning process of the reference station receiver, the pseudorange deviation is corrected by using the pseudorange deviation value of the corresponding frequency point obtained in step 6) based on the observation frequency point used for positioning, thereby improving the positioning performance of the reference station receiver.

[0065] The method for constructing the geometrically inverse observation equations for multiple stations and multiple satellites in step 1) is as follows, taking reference station receiver i and navigation satellite j as an example:

[0066] The pseudorange observations at frequencies F1 and F2 are subtracted to obtain the sum of the ionospheric delay difference between F1 and F2, the receiver inter-symbol bias, and the navigation satellite inter-symbol bias, as detailed below:

[0067]

[0068] Where: ΔP F1-F2 ΔIONO is the difference between the pseudorange observations at frequencies F1 and F2. F1-F2 The difference in ionospheric delay between the F1 and F2 frequency points, and These are the inter-symbol offsets for reference station receiver i and navigation satellite j, respectively. Due to ΔIONO... F1-F2 The global ionospheric electron content map (GIM) provided by the IGS Analysis Center can be used for calculation, therefore the above formula can be written as:

[0069]

[0070] in, This represents the difference in pseudorange observations after deducting the effects of the ionosphere. The above equation is the geometrically unrelated observation equation for reference station receiver i to navigation satellite j. Similarly, the geometrically unrelated observation equation for all reference station receivers to all navigation satellites can be constructed.

[0071] Step 3) obtains the pseudorange deviation values ​​for each navigation satellite, specifically as follows:

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

[0073]

[0074] in, This refers to the inter-symbol offset parameters of navigation satellite j between the F1 and F2 frequencies, as released by the IGS Analysis Center. and These represent the pseudorange deviations of navigation satellite j at frequencies F1 and F2, respectively.

[0075] Step 4) involves static PPP solution, specifically:

[0076] 41) The pseudorange observations and carrier phase observations at the two frequency points F1 and F2 of the reference station receiver are respectively combined into a dual-frequency ionospheric-free combination. Taking the reference station receiver i and navigation satellite j as an example, the specific 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, and the satellite position can be calculated based on the precise orbit of the navigation satellite published by the IGS Analysis Center; c is the speed of light, δt i and δt j Δtrop represents the clock bias of the reference station receiver i and the clock bias of the navigation satellite j, respectively. The navigation satellite clock bias can be calculated based on the precise clock bias of the navigation satellite published by the IGS Analysis Center. Δtrop is the tropospheric delay, Δecc is the effect of station eccentricity (receiver antenna phase center), Δpco is the effect of satellite antenna phase center, Δrel is the relativistic effect, Δgtide is the station tidal correction, and Δwindup is the effect of satellite antenna phase winding. All effects are calculated by the model. λ is the wavelength of the dual-frequency ionospheric combination; N is the phase ambiguity of the dual-frequency ionospheric combination carrier; Δmultipath is the pseudorange multipath effect; ε code and ε phs The observation noise for pseudorange and carrier phase are respectively; P IF and L IF These are the pseudorange and carrier phase observations after the dual-frequency ionosphere-free combination, respectively, and we have:

[0080]

[0081] f1 and f2 are the frequencies of F1 and F2, respectively; P1 and P2 are the pseudorange observations of F1 and F2, respectively; and L1 and L2 are the carrier phase observations of F1 and F2, respectively.

[0082] 42) Based on the dual-frequency ionospheric-free combined observation data of each reference station receiver obtained in step 41), perform static PPP calculation. 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.

[0083] Step 5) obtains the final pseudorange deviation value for each navigation satellite by averaging the pseudorange deviations of the multi-station receivers, specifically as follows:

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

[0085]

[0086] in: Let k be the pseudorange residual of reference station receiver i for navigation satellite j at epoch t, ​​and k be the total number of epochs. The pseudorange deviation value of navigation satellite j is calculated by the reference station receiver i.

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

[0088]

[0089] Where: m is the total number of reference station receivers, This represents the final combined value of the pseudorange deviation at the two frequency points F1 and F2 without ionosphere.

[0090] Step 6) involves calculating the pseudorange deviation values ​​at frequency F1 and frequency F2 for each navigation satellite.

[0091] 61) Take the pseudorange deviation difference between each navigation satellite at the two frequency points F1 and F2 obtained in step 3). Taking navigation satellite j as an example, the details are as follows:

[0092]

[0093] in: The inter-code offset of navigation satellite j obtained in step 2) is... This refers to the inter-symbol offset parameters of navigation satellite j between the F1 and F2 frequencies, as released by the IGS Analysis Center. and These represent the pseudorange deviations of navigation satellite j at frequencies F1 and F2, respectively.

[0094] 62) Take the pseudorange deviation dual-frequency ionospheric combination of each navigation satellite obtained in step 5) at the F1 and F2 frequencies. Taking navigation satellite j as an example, the details are as follows:

[0095]

[0096] in: f1 and f2 are the combined values ​​of the pseudorange deviations of the two frequency points F1 and F2 obtained in step 52); f1 and f2 are the frequencies of the F1 and F2 frequency points, respectively.

[0097] 63) Solve the equations from steps 61) and 62) to obtain the pseudorange deviation at frequency F1 and frequency F2 of each navigation satellite.

[0098] Step 7) improves the positioning performance of the reference station receiver, specifically as follows:

[0099] 71) During single-frequency positioning processing at the F1 or F2 frequency point of the reference station receiver, the pseudorange observation values ​​at the F1 or F2 frequency point of the corresponding navigation satellite are subtracted from the pseudorange deviation values ​​at the F1 or F2 frequency point of each navigation satellite obtained in step 63) to achieve pseudorange deviation correction of the navigation satellite and improve single-frequency positioning performance.

[0100] 72) When the reference station receiver performs F1 / F2 dual-frequency combined positioning processing, it deducts the pseudorange deviation values ​​of the F1 frequency point and the F2 frequency point of each navigation satellite obtained in step 63) from the pseudorange observation values ​​of the corresponding navigation satellites to realize pseudorange deviation correction of navigation satellites and improve dual-frequency positioning performance.

[0101] This application provides a computer-readable storage medium storing computer instructions that, when executed on a computer, cause the computer to perform... Figure 1 The method described.

[0102] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage and optical storage) containing computer-usable program code.

[0103] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0104] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0105] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0106] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

[0107] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A method for correcting pseudorange deviations of navigation satellites based on the absence of geometric and ionospheric combinations, characterized in that, Includes the following steps: 1) Using m identical reference station receivers to form a regional monitoring network, perform geometrically non-combined data processing on the pseudorange observations of the two frequency points F1 and F2 of each reference station receiver to construct a geometrically non-combined observation equation for multiple stations and multiple satellites; 2) Using the geometric-free observation equations for multiple stations and multiple satellites obtained in step 1), the DCB parameters of m reference station receivers and n navigation satellites are obtained by using the least squares whole network solution method; 3) Using the DCB parameters of the n navigation satellites obtained in step 2), the difference is calculated with the DCB parameters of the corresponding navigation satellites released by the IGS analysis center to obtain the pseudorange deviation value of each navigation satellite. The pseudorange deviation value is the difference between the pseudorange deviations of the reference station receiver at the two frequency points F1 and F2. 4) Using the pseudorange and carrier phase observations of the receivers at frequencies F1 and F2 of each reference station, select the precise orbit and clock error products of navigation satellites released by the IGS Analysis Center to perform static precise single-point positioning calculations; 5) Extract the pseudorange deviation of each navigation satellite from the pseudorange residuals of the static precise single-point positioning solution of each reference station receiver obtained in step 4). Obtain the final pseudorange deviation value of each navigation satellite by averaging the pseudorange deviations of the multi-station receivers. The pseudorange deviation value is the dual-frequency non-ionospheric combination value of the pseudorange deviation of the reference station receiver at the F1 and F2 frequencies. 6) Take the difference between the pseudorange deviations of each navigation satellite at the two frequencies F1 and F2 obtained in step 3), and take the combination of the pseudorange deviations of each navigation satellite at the two frequencies F1 and F2 obtained in step 5). Combine the two to solve for the pseudorange deviation values ​​of each navigation satellite at the F1 frequency and the F2 frequency. 7) During the positioning process of the reference station receiver, the pseudorange deviation is corrected by using the pseudorange deviation value of the corresponding frequency point obtained in step 6) based on the observation frequency point used for positioning, thereby improving the positioning performance of the reference station receiver.

2. The pseudorange deviation correction method for navigation satellites based on geometrically and ionospherically free combinations as described in claim 1, characterized in that, Step 1) describes the construction of a geometrically inverse observation equation for multiple stations and multiple satellites. Specifically, for reference station receiver i and navigation satellite j, the equation is as follows: The pseudorange observations at frequencies F1 and F2 are subtracted to obtain the sum of the ionospheric delay difference between F1 and F2, the receiver inter-symbol bias, and the navigation satellite inter-symbol bias, as detailed below: Where: ΔP F1-F2 ΔIONO is the difference between the pseudorange observations at frequencies F1 and F2. F1-F2 The difference in ionospheric delay between the F1 and F2 frequency points, and These represent the inter-symbol offsets for reference station receiver i and navigation satellite j, respectively; due to ΔIONO F1-F2 The above formula is calculated using the global ionospheric electron content map provided by the IGS Analysis Center, and therefore can be written as: in, The difference between pseudorange observations after deducting the influence of the ionosphere is given. The above equation is the geometrically uncombined observation equation for reference station receiver i to navigation satellite j. The same method is used to construct the multi-station, multi-satellite geometrically uncombined observation equation for all reference station receivers to all navigation satellites.

3. The pseudorange deviation correction method for navigation satellites based on the absence of geometric combination and ionosphere combination as described in claim 2, characterized in that, Step 3) involves obtaining the pseudorange deviation values ​​for each navigation satellite, specifically as follows: The DCB parameters of the n navigation satellites obtained in step 2) are subtracted from the corresponding DCB parameters of the navigation satellites published by the IGS analysis center. For reference station receiver i and navigation satellite j, the specific details are as follows: in, This refers to the inter-symbol offset parameters of navigation satellite j between the F1 and F2 frequencies, as released by the IGS Analysis Center. and These represent the pseudorange deviations of navigation satellite j at frequencies F1 and F2, respectively.

4. The pseudorange deviation correction method for navigation satellites based on geometrically and ionospherically free combinations as described in claim 3, characterized in that, Step 4) involves performing static precise single-point positioning calculations, specifically: 41) The pseudorange observations and carrier phase observations at the two frequency points F1 and F2 of the reference station receiver are respectively combined into a dual-frequency ionospheric-free combination. For the reference station receiver i and the navigation satellite j, the specifics 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, and the satellite position is calculated based on the precise orbits of navigation satellites published by the IGS analysis center; c is the speed of light. and δt j These represent the clock bias of the reference station receiver i and the clock bias of the navigation satellite j, respectively. The navigation satellite clock bias is calculated based on the precise clock bias of navigation satellites published by the IGS Analysis Center. Δtrop is the tropospheric delay, Δecc is the effect of station eccentricity, Δpco is the effect of satellite antenna phase center, Δrel is the relativistic effect, Δgtide is the station tidal correction, and Δwindup is the effect of satellite antenna phase winding. All these effects are calculated by the model. λ is the wavelength of the dual-frequency ionosphere-free combination; N is the phase ambiguity of the dual-frequency ionosphere-free combination carrier; Δmultipath is the pseudorange multipath effect; ε code and ε phs The observation noise for pseudorange and carrier phase are respectively; P IF and L IF These are the pseudorange and carrier phase observations after the dual-frequency ionosphere-free combination, respectively, and we have: f1 and f2 are the frequencies of F1 and F2 respectively, P1 and P2 are the pseudorange observations of F1 and F2 respectively, and L1 and L2 are the carrier phase observations of F1 and F2 respectively. 42) Based on the dual-frequency ionospheric-free combined observation data of each reference station receiver obtained in step 41), perform static precise single-point positioning calculation. 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 pseudorange deviation correction method for navigation satellites based on geometrically and ionospherically free combinations according to claim 4, characterized in that, Step 5) describes obtaining the final pseudorange deviation value for each navigation satellite by averaging the pseudorange deviations of the multi-station receivers. Specifically: 51) From the pseudorange residuals obtained in step 4) of the static precise single-point positioning solution for each reference station receiver, the pseudorange deviation of each navigation satellite is extracted by solving the mean. For reference station receiver i and navigation satellite j, the specific details are as follows: in: Let k be the pseudorange residual of reference station receiver i for navigation satellite j at epoch t, ​​and k be the total number of epochs. The pseudorange deviation value of navigation satellite j calculated for reference station receiver i; 52) The final pseudorange deviation value for each navigation satellite is obtained by averaging the pseudorange deviations of multiple reference station receivers. For navigation satellite j, the specific method is as follows: Where: m is the total number of reference station receivers, This represents the final combined value of the pseudorange deviation at the two frequency points F1 and F2 without ionosphere.

6. The pseudorange deviation correction method for navigation satellites based on geometrically and ionospherically free combinations as described in claim 5, characterized in that, Step 6) involves calculating the pseudorange deviation values ​​at frequency F1 and frequency F2 for each navigation satellite, specifically as follows: 61) Take the pseudorange difference between each navigation satellite at the F1 and F2 frequencies obtained in step 3). For navigation satellite j, the specific difference is as follows: in: The inter-code offset of navigation satellite j obtained in step 2) is... This refers to the inter-symbol offset parameters of navigation satellite j between the F1 and F2 frequencies, as released by the IGS Analysis Center. and These are the pseudorange deviations of navigation satellite j at frequencies F1 and F2, respectively. 62) Take the pseudorange deviation dual-frequency ionospheric combination of each navigation satellite obtained in step 5) at the F1 and F2 frequencies. For navigation satellite j, the specific details are as follows: in: The pseudorange deviations at frequencies F1 and F2 obtained in step 52) are the combined values ​​of the two frequencies without ionosphere; f1 and f2 are the frequencies of frequencies F1 and F2, respectively. 63) Solve the equations from steps 61) and 62) to obtain the pseudorange deviation at frequency F1 and frequency F2 of each navigation satellite.

7. The pseudorange deviation correction method for navigation satellites based on the combination of no geometric combination and no ionospheric combination as described in claim 6, characterized in that, Step 7) describes the improvement of the positioning performance of the reference station receiver, specifically as follows: 71) During single-frequency positioning processing at the F1 or F2 frequency point of the reference station receiver, the pseudorange observation values ​​at the F1 or F2 frequency point of the corresponding navigation satellite are subtracted from the pseudorange deviation values ​​at the F1 or F2 frequency point of each navigation satellite obtained in step 63) to achieve pseudorange deviation correction of the navigation satellite and improve single-frequency positioning performance. 72) When the reference station receiver performs F1 / F2 dual-frequency combined positioning processing, it deducts the pseudorange deviation values ​​of the F1 frequency point and the F2 frequency point of each navigation satellite obtained in step 63) from the pseudorange observation values ​​of the corresponding navigation satellites to realize pseudorange deviation correction of navigation satellites and improve 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, it implements the steps of the method as described in any one of claims 1 to 7.

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, it implements the steps of the method as described in any one of claims 1 to 7.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1 to 7.

Images