Methods, devices, equipment and media for determining pseudorange bias in satellite systems

Abstract

This application discloses a method, apparatus, device, and medium for determining pseudorange bias in a satellite system, belonging to the field of satellite signal processing technology. The method includes: fixing the ambiguities of a first double-difference wide-lane ambiguity, a second double-difference wide-lane ambiguity, a first double-difference narrow-lane ambiguity, and a second double-difference narrow-lane ambiguity to determine the atmospheric delay of the satellite system, as well as a third double-difference wide-lane ambiguity and a third double-difference narrow-lane ambiguity; based on the atmospheric delay, searching for the third double-difference wide-lane ambiguity to determine the wide-lane ambiguity value, and searching for the third double-difference narrow-lane ambiguity to determine the narrow-lane ambiguity value; based on the wide-lane ambiguity value and the narrow-lane ambiguity value, obtaining the target atmospheric delay between the first and second satellites; and substituting the target atmospheric delay into the double-difference pseudorange observation equation to obtain the target pseudorange bias of the satellite system. This method can estimate the pseudorange bias of a receiver-observed satellite system under long baseline conditions.

Description

Technical Field

[0001] This application belongs to the field of satellite signal processing technology, and in particular relates to a method, apparatus, device and medium for determining pseudorange deviation of a satellite system. Background Technology

[0002] On the satellite side, the new generation of BeiDou-3 system (BDS-3) satellites can be seen as a supplement to the existing BeiDou-2 system (BDS-2) satellites, enabling the original BDS-2 service coverage to extend to the whole world.

[0003] However, at some receivers, in order to be compatible with the legacy signals of the earlier BDS-2, only a BDS-3 signal processing unit was added. This means that although there are overlapping signals B1I / B3I in the satellite system composed of BDS-3 and BDS-2, there are still inconsistencies in the hardware delay of the signals after passing through different receivers. Therefore, when using BDS-2 and BDS-3 observation data for GNSS data processing, the hardware deviations at the receiver end must be carefully handled.

[0004] In practical applications, when receivers are separated during actual use, due to firmware upgrades or force majeure, the two receivers, which are far apart, cannot form a zero baseline. The existing method estimates pseudorange deviation based on the zero baseline, which cannot estimate the pseudorange deviation of the receiver observing the satellite system in the case of a long baseline. Summary of the Invention

[0005] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a method for determining the pseudorange bias of a satellite system, which can estimate the pseudorange bias of the receiver-observed satellite system under long baseline conditions.

[0006] In a first aspect, this application provides a method for determining pseudorange bias in a satellite system, the satellite system including a first satellite, a first reference satellite of the first satellite, a second satellite and a second reference satellite of the second satellite, and a base station and a rover station for observing the first satellite, the second satellite, the first reference satellite and the second reference satellite, wherein the base station and the rover station are equipped with receivers, and the method includes:

[0007] The receiver acquires the observation signal to determine, based on the observation signal, a first double-difference wide-lane ambiguity between the first satellite and the first reference satellite, a second double-difference wide-lane ambiguity between the second satellite and the second reference satellite, a first double-difference narrow-lane ambiguity between the first satellite and the first reference satellite, and a second double-difference narrow-lane ambiguity between the first reference satellite and the second reference satellite.

[0008] The ambiguity of the first double-difference wide-lane ambiguity, the second double-difference wide-lane ambiguity, the first double-difference narrow-lane ambiguity, and the second double-difference narrow-lane ambiguity is fixed to determine the atmospheric delay of the satellite system, as well as the third double-difference wide-lane ambiguity and the third double-difference narrow-lane ambiguity between the first reference satellite and the second reference satellite.

[0009] Based on the atmospheric delay, the third double-difference wide-lane ambiguity is searched to determine the wide-lane ambiguity value between the first satellite and the second satellite, and the third double-difference narrow-lane ambiguity is searched to determine the narrow-lane ambiguity value between the first satellite and the second satellite.

[0010] Based on the wide-lane ambiguity value and the narrow-lane ambiguity value, the target atmospheric delay between the first satellite and the second satellite is obtained;

[0011] Substituting the target atmospheric delay into the double-difference pseudorange observation equation, the target pseudorange bias of the satellite system is obtained.

[0012] According to one embodiment of this application, the step of searching for the third double-difference wide-lane ambiguity based on the atmospheric delay to determine the wide-lane ambiguity value between the first satellite and the second satellite includes:

[0013] Based on the floating-point solution of the third double-difference wide-lane ambiguity between the first reference star and the second reference star, the wide-lane search range and the candidate wide-lane integer ambiguities of the third double-difference wide-lane ambiguity are determined.

[0014] Based on the wide alley search range, the candidate wide alley integer ambiguity is searched, and the deviation degree of the candidate wide alley integer ambiguity is determined.

[0015] Based on the atmospheric delay, the atmospheric delay difference corresponding to the degree of deviation is calculated, and the wide-lane ambiguity value is determined from the candidate wide-lane integer ambiguities.

[0016] According to one embodiment of this application, the wide alley search range is:

[0017]

[0018] Where floor(·) and ceil(·) are floor down and floor up respectively, and WL(·) represents the wide alley combination of the pseudo-millimeter part. The third double-difference wide-lane ambiguity; The pseudorange deviation between the first and second satellites at the first frequency point. λ represents the pseudorange deviation between the first and second satellites at the second frequency point. wl is the wide-lane wavelength of the satellite system.

[0019] According to one embodiment of this application, the third double-difference wide-lane ambiguity and the third double-difference narrow-lane ambiguity are obtained based on the following steps:

[0020] The first double-difference wide-lane ambiguity and the second double-difference wide-lane ambiguity are differentially analyzed to obtain the third double-difference wide-lane ambiguity;

[0021] The third double-difference narrow alley ambiguity is obtained by differentiating the first double-difference narrow alley ambiguity and the second double-difference narrow alley ambiguity.

[0022] According to one embodiment of this application, the double-difference pseudorange observation equation is:

[0023]

[0024] In the formula, E{·} represents taking the expectation. It is the pseudorange observation value of the first satellite at the i-th frequency point minus the model prior value of the observed prior pseudorange residual. It is the pseudorange observation value of the second satellite at the i-th frequency point minus the model prior value of the observed prior pseudorange residual. It is the phase observation value of the first satellite at the i-th frequency point minus the observed value of the model prior value, which is the prior phase residual. It is the phase observation value of the second satellite at the i-th frequency point minus the observed value of the model prior value, which is the prior phase residual. It is the clock bias of the GNSS receiver, γ i ，g It is the amplification factor of the ionosphere at the i-th frequency point. It is the ionospheric error experienced in the observations of the first satellite. This refers to the ionospheric error in the observations from the second satellite. It is the projection coefficient of the first satellite's troposphere. It is the projection coefficient of the second satellite's troposphere. It is the pseudorange hardware delay error between the satellite end and the receiver end in the first satellite observation. It is the pseudorange hardware delay error between the satellite end and the receiver end in the second satellite observation. These are the ambiguity parameters of the first satellite. This is the ambiguity parameter of the second satellite, T. r and T b These are the tropospheric parameters for the rover r and the base station b, respectively. and The tropospheric parameters T for the rover r and the base station b r and T b The corresponding projection functions are C2 for the first satellite and C3 for the second satellite. This represents the difference in pseudorange deviation between the first satellite and the second satellite.

[0025] According to one embodiment of this application, when the observed signal includes the wide-lane wavelength of the satellite system, the double-difference phase and pseudorange observations of the first satellite and the first reference satellite, and the frequency value, the calculation formula for the first double-difference wide-lane ambiguity is as follows:

[0026]

[0027] In the formula, s is the satellite identifier. λ is the first double-difference wide-lane ambiguity between the first satellite BDS-2 and the first reference satellite q2 calculated based on the rover r and the base station b. wl The first double-difference wide-lane ambiguity The corresponding wide-lane wavelength; The phase difference is based on the i-th frequency point of the first satellite BDS-2 and the first reference satellite q2 at the rover station r and the base station b. For pseudorange observations at the i-th frequency point of the first satellite BDS-2 and the first reference satellite q2 based on the rover r and the base station b, i (i = 1, 2, 3) is the frequency number, f i Let be the frequency value of the i-th (i = 1, 2, 3) frequency point.

[0028] According to one embodiment of this application, the target atmospheric delay includes a target double-difference ionospheric delay and a target tropospheric delay. Substituting the target atmospheric delay into the double-difference pseudorange observation equation to obtain the target pseudorange bias of the satellite system includes:

[0029] Substituting the target double-difference ionospheric delay and the target tropospheric delay into the double-difference pseudorange observation equation, we obtain the pseudorange bias estimates for the first satellite and the second satellite;

[0030] The pseudorange bias estimate is smoothed over multiple epochs to obtain the target pseudorange bias.

[0031] Secondly, this application provides a pseudorange deviation determination device for a satellite system, the satellite system including a first satellite, a first reference satellite of the first satellite, a second satellite and a second reference satellite of the second satellite, and a base station and a rover station for observing the first satellite, the second satellite, the first reference satellite and the second reference satellite, wherein the base station and the rover station are equipped with receivers, and the device includes:

[0032] The acquisition module is used to acquire the observation signal of the receiver, so as to determine the first double-difference wide-lane ambiguity between the first satellite and the first reference satellite, the second double-difference wide-lane ambiguity between the second satellite and the second reference satellite, the first double-difference narrow-lane ambiguity between the first satellite and the first reference satellite, and the second double-difference narrow-lane ambiguity between the first reference satellite and the second reference satellite based on the observation signal.

[0033] The first processing module is used to fix the ambiguity of the first double-difference wide-lane ambiguity, the second double-difference wide-lane ambiguity, the first double-difference narrow-lane ambiguity and the second double-difference narrow-lane ambiguity, determine the atmospheric delay of the satellite system, and the third double-difference wide-lane ambiguity and the third double-difference narrow-lane ambiguity between the first reference satellite and the second reference satellite.

[0034] The second processing module is used to search for the third double-difference wide-lane ambiguity based on the atmospheric delay to determine the wide-lane ambiguity value between the first satellite and the second satellite, and to search for the third double-difference narrow-lane ambiguity to determine the narrow-lane ambiguity value between the first satellite and the second satellite.

[0035] The third processing module is used to obtain the target atmospheric delay between the first satellite and the second satellite based on the wide-lane ambiguity value and the narrow-lane ambiguity value;

[0036] The fourth processing module is used to substitute the target atmospheric delay into the double-difference pseudorange observation equation to obtain the target pseudorange deviation of the satellite system.

[0037] Thirdly, this application provides an electronic device including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the pseudorange deviation determination method for a satellite system as described in the first aspect above.

[0038] Fourthly, this application provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the pseudorange deviation determination method for a satellite system as described in the first aspect above.

[0039] Fifthly, this application provides a chip including a processor and a communication interface, the communication interface being coupled to the processor, the processor being used to run programs or instructions to implement the pseudorange deviation determination method for satellite systems as described in the first aspect.

[0040] In a sixth aspect, this application provides a computer program product, including a computer program that, when executed by a processor, implements the pseudorange deviation determination method for a satellite system as described in the first aspect above.

[0041] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application.

[0042] The pseudorange deviation determination method for satellite systems provided by this invention has the following advantages over existing technologies:

[0043] (1) By fixing the ambiguity of the first double-difference wide lane, the second double-difference wide lane, the first double-difference narrow lane, and the second double-difference narrow lane, and considering atmospheric delay, the positioning accuracy is improved. The ambiguity of the third double-difference wide lane and the third double-difference narrow lane is searched to achieve ambiguity fixing with a higher accuracy. This enables long-distance estimation of the pseudorange deviation of the receiver observation of the first and second satellites, and has a wider range of applications.

[0044] (2) By introducing the pseudorange deviation between receiver systems into the ionosphere-free model or the non-differential non-combination model, the inconsistency in the hardware delay of the signal after passing through different receivers will be absorbed.

[0045] (3) It can estimate the pseudorange deviation of the receiver observation of the first and second satellites with long spacing, without being limited by experimental conditions, and can extract the pseudorange deviation of a single frequency point. Attached Figure Description

[0046] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0047] Figure 1 This is a schematic diagram of the structure of the satellite system provided in the embodiments of this application;

[0048] Figure 2 This is a flowchart illustrating the pseudorange deviation determination method for a satellite system provided in an embodiment of this application.

[0049] Figure 3 This is a schematic diagram of the pseudorange deviation determination system for a satellite system provided in the embodiments of this application;

[0050] Figure 4 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0051] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0052] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0053] The pseudorange deviation determination method, pseudorange deviation determination device, electronic device, and readable storage medium for satellite systems provided in this application will be described in detail below with reference to the accompanying drawings and through specific embodiments and application scenarios.

[0054] The pseudorange deviation determination method for satellite systems can be applied to terminals, specifically executed by hardware or software within the terminals.

[0055] The terminal includes, but is not limited to, portable communication devices such as mobile phones or tablets with touch-sensitive surfaces (e.g., touchscreen displays and / or touchpads). It should also be understood that, in some embodiments, the terminal may not be a portable communication device, but rather a desktop computer with touch-sensitive surfaces (e.g., touchscreen displays and / or touchpads).

[0056] The following embodiments describe a terminal including a display and a touch-sensitive surface. However, it should be understood that the terminal may include one or more other physical user interface devices such as a physical keyboard, mouse, and joystick.

[0057] The pseudorange deviation determination method for a satellite system provided in this application embodiment can be executed by an electronic device or a functional module or entity in an electronic device that can implement the pseudorange deviation determination method for the satellite system. The electronic devices mentioned in this application embodiment include, but are not limited to, mobile phones, tablets, computers, cameras, and wearable devices. The pseudorange deviation determination method for a satellite system provided in this application embodiment will be described below using an electronic device as the execution subject as an example.

[0058] like Figure 1 As shown, the satellite system includes a first satellite, a first reference satellite of the first satellite, a second satellite and a second reference satellite of the second satellite, as well as a base station and a rover station for observing the first satellite, the second satellite, the first reference satellite and the second reference satellite, and the base station and the rover station are equipped with receivers.

[0059] In the case of the BeiDou system, the first satellite can be BDS-2, the second satellite can be BDS-3, the first reference satellite q2 can be the satellite with the highest elevation angle inside the first satellite BDS-2, and the second reference satellite q3 can be the satellite with the highest elevation angle inside the second satellite BDS-3, forming the (Melbourne–Wübbena)MW combined observation value.

[0060] In embodiments of this application, a long baseline deployment can be used between the base station and the rover.

[0061] like Figure 2 As shown, the pseudorange deviation determination method of the satellite system includes steps 210 to 250.

[0062] Step 210: Obtain the observation signal of the receiver, and determine the first double-difference wide-lane ambiguity between the first satellite and the first reference satellite, the second double-difference wide-lane ambiguity between the second satellite and the second reference satellite, the first double-difference narrow-lane ambiguity between the first satellite and the first reference satellite, and the second double-difference narrow-lane ambiguity between the first reference satellite and the second reference satellite based on the observation signal.

[0063] Among them, the observation signals are the phase observation values ​​obtained by the base station and the rover station respectively observing the first satellite BDS-2, the first reference satellite q2, the second satellite BDS-3, and the second reference satellite q3.

[0064] Among them, Double-Difference Wide-Lane Ambiguity refers to the use of double-difference (satellite difference, inter-satellite difference) technology to eliminate hardware delay biases contained in pseudorange and phase combination observations in order to restore the integer characteristics of ambiguity. Here, the wide-lane ambiguity value refers to the fixed solution of Double-Difference Wide-Lane Ambiguity.

[0065] Wide-lane wavelength is the actual distance corresponding to the wide-lane ambiguity period, used to determine integer ambiguity.

[0066] Narrow-lane ambiguity is the ambiguity involved in processing narrow-lane combinations in GNSS receivers. It is used together with wide-lane combinations to recover the original ambiguity from the signal, thereby extracting high-precision position information.

[0067] Narrow-lane wavelength is a measure of the period of narrow-lane ambiguity in GNSS dual-frequency measurements by combining the wavelengths of two frequency signals. It resolves phase ambiguity issues and is used for precise positioning.

[0068] In related technologies, the zero-baseline approach pre-estimating pseudorange bias for correction, treating BDS-2 and BDS-3 as a single system when there is no significant systematic bias between the overlapping signals, has certain limitations. This approach only used the Septentrio receiver, which has good compatibility within the Multi-GNSS Experiment (MGEX) network maintained by the International GNSS Service (IGS), for data processing. This confirmed that the absolute value of the inter-system bias (ISB) at the receiver end could reach several meters. Although no systematic bias was found in the phase observations, the presence of ISB affects the convergence performance of PPP floating-point solutions, contaminates the integer characteristics of ambiguity, and prevents long-range baseline solutions or precise point positioning ambiguity fixation (PPP-IAR) from performing BDS-23 inter-system ambiguity fixation.

[0069] In the embodiments of this application, by introducing the pseudorange deviation between receiver systems into the ionosphere-free model or the non-differential non-combination model, the inconsistency in the hardware delay of the signal after passing through different receivers will be absorbed.

[0070] Zero baseline analysis was used to investigate the pseudorange bias of the first satellite BDS-2 and the second satellite BDS-3 with different receivers. After correcting the bias, the wide-lane ambiguity was fixed. After pseudorange correction, the mean of the fractional part of the wide-lane ambiguity was reduced from -0.59 cycles to 0.03 cycles.

[0071] In terms of bias extraction, the zero baseline method can extract the pseudorange reference bias under the ionosphere-free combined reference, but it cannot extract the pseudorange bias of a single frequency point. Moreover, the zero baseline method is usually limited by experimental conditions.

[0072] Zero baseline is used to characterize the scenario where the distance between the two receivers is zero during the measurement process.

[0073] In actual implementation, long-distance real-time dynamic positioning (RTK) fixed procedures were carried out on the first satellite BDS-2 and the second satellite BDS-3 respectively. The ambiguity fixing strategy of wide lane first and then narrow lane was adopted. The goal of fixing the ambiguity is to determine the specific values ​​of these integer multiple wavelengths, thereby improving the positioning accuracy.

[0074] It should be noted that, in the embodiments of this application, the pseudorange deviation determination method of the satellite system is described using BeiDou as an example. Since only the BeiDou system is considered, the navigation constellation identifier g will not be given again in the following.

[0075] In some embodiments, when the observed signal includes the wide-lane wavelength, the double-difference phase and pseudorange observations of the first satellite BDS-2 and the first reference satellite q2, and the frequency value, the formula for calculating the first double-difference wide-lane ambiguity is as follows:

[0076]

[0077] In the formula, s is the satellite identifier. λ is the first double-difference wide-lane ambiguity between the first satellite BDS-2 and the first reference satellite q2 calculated based on the rover r and the base station b. wl The first double-difference wide-lane ambiguity The corresponding wide-lane wavelength; The phase difference is based on the i-th frequency point of the first satellite BDS-2 and the first reference satellite q2 at the rover station r and the base station b. For pseudorange observations at the i-th frequency point of the first satellite BDS-2 and the first reference satellite q2 based on the rover r and the base station b, where i (i = 1, 2, 3) is the frequency number of the frequency point, f i Let be the frequency value of the i-th (i = 1, 2, 3) frequency point.

[0078] Similarly, the second double-difference wide-lane ambiguity and the second wide-lane ambiguity value of the second satellite BDS-3 and the second reference satellite q3 can be obtained, which will not be elaborated here.

[0079] Step 220: Fix the ambiguity of the first double-difference wide-lane ambiguity, the second double-difference wide-lane ambiguity, the first double-difference narrow-lane ambiguity, and the second double-difference narrow-lane ambiguity to determine the atmospheric delay of the satellite system, as well as the third double-difference wide-lane ambiguity and the third double-difference narrow-lane ambiguity between the first reference satellite and the second reference satellite.

[0080] Atmospheric delay includes double-difference ionospheric delay and tropospheric delay.

[0081] Double-difference ionospheric correction is a method used to eliminate ionospheric effects. GNSS signals are refracted when passing through the ionosphere, which leads to errors in pseudorange and carrier phase observations. Ionospheric errors affect positioning accuracy and require effective correction.

[0082] It is understandable that in double-difference wide-lane ambiguity, the first is based on the double-difference phase of rover r and base station b. and pseudo-distance observation As a combined observation, error terms related to geometric distance and satellites are eliminated, and due to the processing by the first satellite BDS-2 and the second satellite BDS-3 subsystems, the error at the receiver end can also be eliminated by inter-satellite single difference.

[0083] Therefore, the first double-difference wide-lane ambiguity has integer characteristics. After smoothing, the noise caused by pseudo-range can be suppressed. Directly rounding the first double-difference wide-lane ambiguity can achieve ambiguity fixation with a high accuracy.

[0084] It is understandable that after fixing the wide alley ambiguity, the narrow alley ambiguity can be derived from the floating-point ionospheric ambiguity and processed for the first satellite BDS-2 and the second satellite BDS-3 subsystems. The calculation methods are the same for both. The following explanation will take the calculation of the first double-difference narrow alley ambiguity sum of the first satellite BDS-2 and the first reference satellite q2 as an example.

[0085] In this step, the formula for calculating the first double-difference narrow-lane ambiguity is:

[0086]

[0087] In the formula, s is the satellite identifier, and λ nl The wavelength of the first narrow alleyway corresponding to the first double-difference narrow alleyway ambiguity. This is the first double-difference original ambiguity, which, due to its narrow-lane wavelength, is subsequently referred to as the first double-difference narrow-lane ambiguity. It is the double-difference ambiguity at the i-th frequency point. The double-difference wide-lane ambiguity of the first satellite; IF(·) is the ionospheric-free combination operator, f i Let be the frequency value of the i-th (i = 1, 2, 3) frequency point.

[0088] The formula for calculating the non-ionospheric combination operator IF(·) is as follows:

[0089]

[0090] In the formula, g is the navigation constellation identifier, i (i = 1, 2, 3) is the frequency number, and γ1 is the ionospheric amplification factor at the first frequency point, specifically expressed as follows: Where λ i γ is the wavelength at the corresponding frequency point; γ2 is the amplification factor of the ionosphere at the second frequency point, and its specific expression is:

[0091] It is understandable that the calculation method for the second double-difference narrow alley ambiguity is the same as that for the first double-difference narrow alley ambiguity, and will not be repeated here.

[0092] In satellite systems, double difference ionospheric delay is used to characterize the effect of the ionosphere on signal propagation delay, while tropospheric delay is used to characterize the effect of the atmospheric troposphere on signal propagation delay.

[0093] In the double-difference form, the narrow-lane ambiguity also exhibits integer properties. Fixed solutions for the narrow-lane ambiguity can be obtained by using ambiguity fixing methods such as rounding or LAMBDA (Least-squares AMBiguity Decorrelation Adjustment).

[0094] After fixing the wide-lane and narrow-lane ambiguities, the accurate double-difference ionospheric delay and tropospheric delay can also be derived. The formulas for calculating the double-difference ionospheric delay and tropospheric delay are as follows:

[0095]

[0096] in, It is the double-difference ionospheric delay of the first satellite BDS-2 and the first reference satellite q2; γ1 is the tropospheric delay of the first satellite BDS-2 and the first reference satellite q2; γ2 is the ionospheric amplification factor at the first frequency point; γ1 is the ionospheric amplification factor at the second frequency point; λ1 is the wavelength at the first frequency point; λ2 is the wavelength at the second frequency point. These are double-difference carrier observations; It is a double-difference tropospheric delay; It is the original ambiguity value of the double difference at the first frequency point. This is the original ambiguity value of the double difference at the second frequency point, and its calculation formula is as follows:

[0097]

[0098] in, It is the original ambiguity value of the double difference at the first frequency point. It is the double-difference wide-lane ambiguity of the first satellite.

[0099] Step 230: Based on the atmospheric delay, search for the third double-difference wide-lane ambiguity to determine the wide-lane ambiguity value between the first satellite and the second satellite, and search for the third double-difference narrow-lane ambiguity to determine the narrow-lane ambiguity value between the first satellite and the second satellite.

[0100] It is understandable that in order to obtain the double-difference ionosphere between the first satellite BDS-2 and the second satellite BDS-3, it is also necessary to fix the ambiguity of the first reference satellite q2 and the second reference satellite q3 according to the same fixing strategy. Then, the double-difference ambiguity obtained by fixing the first reference satellite q2 and the second reference satellite q3 is used as a connection to obtain the double-difference ambiguity group with a unified reference for the entire BeiDou system.

[0101] In some embodiments, the third double-difference wide-lane ambiguity and the third double-difference narrow-lane ambiguity are obtained based on the following steps:

[0102] The first double-difference wide-lane ambiguity and the second double-difference wide-lane ambiguity are differentially analyzed to obtain the third double-difference wide-lane ambiguity;

[0103] The third double-difference narrow alley ambiguity is obtained by differentiating the first double-difference narrow alley ambiguity and the second double-difference narrow alley ambiguity.

[0104] In some embodiments, the step of searching for the third double-difference wide-lane ambiguity based on the atmospheric delay to determine the wide-lane ambiguity value between the first satellite and the second satellite includes:

[0105] Based on the floating-point solution of the third double-difference wide-lane ambiguity between the first reference star and the second reference star, the wide-lane search range and the candidate wide-lane integer ambiguities of the third double-difference wide-lane ambiguity are determined.

[0106] Based on the wide alley search range, the candidate wide alley integer ambiguity is searched, and the deviation degree of the candidate wide alley integer ambiguity is determined.

[0107] Based on the atmospheric delay, the atmospheric delay difference corresponding to the degree of deviation is calculated, and the wide-lane ambiguity value is determined from the candidate wide-lane integer ambiguities.

[0108] Atmospheric delay differences include double-difference ionospheric delay differences and tropospheric delay differences.

[0109] Further double-difference finite element analysis is performed between the first reference star q2 and the second reference star q3 to obtain the floating-point solution of the third double-difference wide-lane ambiguity between the first reference star q2 and the second reference star q3, as calculated below:

[0110]

[0111] In the formula, The floating-point solution for the third double-difference wide-lane ambiguity between the first reference star q2 and the second reference star q3; λ wl For the third double-difference wide-lane ambiguity The corresponding wide-lane wavelength; f iLet i be the frequency value of the i-th (i = 1, 2, 3) frequency point; These are the double-difference phase and pseudorange observations based on the first and second frequency points of the first reference satellite and the first reference satellite q2, respectively, from the rover r and the base station b.

[0112] Due to the non-negligible difference between the pseudorange observations of the first satellite BDS-2 and the second satellite BDS-3 in the BeiDou system. and The residual pseudorange bias after double difference Will be absorbed into In terms of ambiguity, making it non-integer in nature means that simply rounding it will introduce a systematic error of approximately plus or minus N cycles.

[0113] To obtain the correct wide-lane ambiguity value, a floating-point solution for the third double-difference wide-lane ambiguity is searched.

[0114] Based on the double-difference pseudorange observation equation, the pseudorange bias at the i-th frequency point can be determined. floating point valuation

[0115] The floating-point solution for the third double-difference wide-lane ambiguity is obtained. Then, the wide alley search range can be determined for the wide alley ambiguity value.

[0116] In some embodiments, the wide lane search range is:

[0117]

[0118] In the formula, floor(·) and ceil(·) are floor down and floor up respectively, and WL(·) represents the wide alley combination of the pseudo-distance part; The pseudorange deviation between the first satellite and the second satellite at the first frequency point. λ represents the pseudorange deviation between the first and second satellites at the second frequency point. wl is the wide-lane wavelength of the satellite system.

[0119] Among them, the candidate wide-lane integer ambiguity can be selected from the floating-point solution of the third double-difference wide-lane ambiguity.

[0120] To determine the correct third double-difference wide-lane ambiguity, the third double-difference narrow-lane ambiguity is obtained by sequentially calculating the integer ambiguities of the candidate wide-lane ambiguities using the floating-point solution method for the third double-difference wide-lane ambiguity. Since there is no systematic error between the phase observations of the first satellite BDS-2 and the second satellite BDS-3, if the correct wide-lane integer ambiguity is input, the narrow-lane integer ambiguity derived from the floating-point solution can be searched to the correct narrow-lane ambiguity.

[0121] The narrow-lane ambiguity value refers to the integer or estimated value of the double-difference narrow-lane ambiguity that is actually calculated. It can directly affect the final positioning accuracy, and the accuracy of the narrow-lane ambiguity value is crucial to improving the positioning accuracy of the satellite system.

[0122] However, when an incorrect wide-lane integer ambiguity is introduced, according to the formula for calculating double-difference narrow-lane ambiguity, a deviation of 1 cycle in the wide-lane integer ambiguity will lead to a decrease in the double-difference narrow-lane ambiguity. Deviation week.

[0123] Based on the calculation formulas for double-difference ionospheric delay and tropospheric delay, the difference in double-difference ionospheric delay caused by erroneous wide-lane integer ambiguities is... The calculation formula can be expressed as:

[0124]

[0125] Tropospheric delay differences caused by incorrect wide-lane integer ambiguities The calculation formula can be expressed as:

[0126]

[0127] Where γ1 is the ionospheric amplification factor at the first frequency point, γ2 is the ionospheric amplification factor at the second frequency point, λ1 is the wavelength at the first frequency point, and λ2 is the wavelength at the second frequency point. The part that is incorrectly fixed in the original L1 ambiguity of the double difference is... The part that is incorrectly fixed in the original L2 ambiguity of the double difference is the part that is incorrect. It is the part with the fixed error of double-difference wide alley ambiguity.

[0128] If the wide-lane ambiguity deviates by 1 cycle, the first double-difference narrow-lane ambiguity... Deviation Substituting the values ​​into the formula for calculating the ionospheric delay difference, we can conclude that the resulting ionospheric error is close to 60 cm, while the tropospheric error is only about 6 cm.

[0129] Therefore, in the first double-difference narrow alley ambiguity During the calculation process, if the reference satellites q2 and q3 are incorrectly fixed, the ionosphere extracted by the first satellite BDS-2 and the second satellite BDS-3 in the BeiDou satellite system will have a reference deviation of at least 60cm.

[0130] Based on the double-difference ionospheric delay difference and the tropospheric delay difference corresponding to each candidate wide-lane integer ambiguity, a discrimination condition is constructed to determine whether the narrow-lane ambiguity values ​​of the first satellite BDS-2 and the second satellite BDS-3 are correctly identified from the candidate wide-lane integer ambiguities.

[0131] For example, the candidate wide-lane integer ambiguity with the smallest difference between the double-difference ionospheric delay and the tropospheric delay can be used as the wide-lane ambiguity value, and the candidate narrow-lane integer ambiguity with the smallest difference between the double-difference ionospheric delay and the tropospheric delay can be used as the narrow-lane ambiguity value.

[0132] Step 240: Based on the wide-lane ambiguity value and the narrow-lane ambiguity value, obtain the target atmospheric delay between the first satellite and the second satellite.

[0133] The target atmospheric delay includes the target double-difference ionospheric delay and the target tropospheric delay.

[0134] In this process, after incorporating the original ambiguities of the first and second frequency points, the target troposphere and ionosphere can be obtained according to the calculation formula. Since the ambiguities of the reference stars of the first and second satellites have been fixed, the target double-difference atmospheric delay reference has been unified at this time.

[0135] The integer characteristic of narrow-lane ambiguity is determined by using the error of the double-difference ionospheric delay before and after fixing the reference star ambiguity as the discrimination condition.

[0136] As can be seen from the above, a deviation of one full cycle in the wide-lane ambiguity will cause a deviation in the ambiguity of phase observations in the B1I band. The number of weeks, approximately 4.33 weeks, affects not only the integer part of the narrow-lane ambiguity but also its fractional part. Normally, the fractional part of the narrow-lane ambiguity is close to zero, but after introducing an incorrect wide-lane ambiguity, the integer property of the narrow-lane ambiguity is weakened. Therefore, checking whether the fractional part of the narrow-lane ambiguity is less than a certain threshold can narrow down the search range of the wide-lane ambiguity in advance.

[0137] Step 250: Substitute the target atmospheric delay into the double-difference pseudorange observation equation to obtain the target pseudorange bias of the satellite system.

[0138] It should be noted that the double-difference pseudorange observation equation is constructed based on the following method:

[0139] First, the single-difference observation equation between GNSS long-range real-time kinematic (RTK) stations in non-combined mode is as follows:

[0140]

[0141] in:

[0142]

[0143] In the formula, E{·} represents taking the expectation. and The pseudorange and phase observation OMC (Observed Minus Computed) values ​​are obtained by subtracting the model values ​​from the pseudorange and phase observation values ​​between rover r and base station b. s is the satellite identifier, g is the navigation constellation identifier, and i (i = 1, 2, 3) is the frequency number of the frequency point. The model values ​​are calculated based on the satellite position and true ground coordinates obtained from broadcast ephemeris or precise ephemeris, taking into account corrections such as solid tides and Earth rotation. The inter-station single-difference receiver clock bias after parameter resetting absorbs the pseudorange hardware delay at pseudorange frequencies L1 and L2. and γ i ，g Let f be the amplification factor of the ionosphere at the i-th frequency, with a value of (f1 / f). i ) 2 f i T is the frequency value of the i-th frequency point; r and T b For the tropospheric parameters of the rover and the base station, and T respectively r and T b The corresponding projection function; For floating-point ambiguity, For the corresponding wavelength; This represents the residual pseudorange error at the receiver at the i-th frequency. Since ionospheric errors in long-range RTK are not negligible, ionospheric parameters need to be set. Used to absorb residual ionosphere between stations.

[0144] Although there is a significant pseudorange bias between the first satellite BDS-2 and the second satellite BDS-3 at the receiver end, there is no systematic error in the phase observations. Therefore, during data processing, the first satellite BDS-2 and the second satellite BDS-3 are still treated as a single navigation system, but an additional pseudorange bias parameter needs to be added to the BDS-3 pseudorange equation. Used to absorb systematic errors. If the single-difference observation equation is limited to processing only BeiDou navigation system observations, then the double-difference pseudorange observation equation can be expanded as follows:

[0145]

[0146] In the formula, E{·} represents taking the expectation. It is the pseudorange observation value of the first satellite at the i-th frequency point minus the model prior value of the observed prior pseudorange residual. It is the pseudorange observation value of the second satellite at the i-th frequency point minus the model prior value of the observed prior pseudorange residual. It is the phase observation value of the first satellite at the i-th frequency point minus the observed value of the model prior value, which is the prior phase residual. It is the phase observation value of the second satellite at the i-th frequency point minus the observed value of the model prior value, which is the prior phase residual. It is the clock bias of the GNSS receiver, γ i ，g It is the amplification factor of the ionosphere at the i-th frequency point. It is the ionospheric error experienced in the observations of the first satellite. This refers to the ionospheric error in the observations from the second satellite. It is the projection coefficient of the first satellite's troposphere. It is the projection coefficient of the second satellite's troposphere. It is the pseudorange hardware delay error between the satellite end and the receiver end in the first satellite observation. It is the pseudorange hardware delay error between the satellite end and the receiver end in the second satellite observation. These are the ambiguity parameters of the first satellite. This is the ambiguity parameter of the second satellite, T. r and T b These are the tropospheric parameters for the rover r and the base station b, respectively. and The tropospheric parameters T for the rover r and the base station b r and T b The corresponding projection functions are C2 for the first satellite and C3 for the second satellite. This represents the difference in pseudorange deviation between the first satellite and the second satellite.

[0147] With zero baseline, both the double-difference ionospheric delay and tropospheric delay are zero. Subtracting the observation equations from the first satellite BDS-2 and the second satellite BDS-3 directly yields the result. The value of .

[0148] However, atmospheric residual errors are not negligible under long baseline conditions. To obtain... To obtain accurate values, precise residual errors in the ionosphere and troposphere need to be calculated.

[0149] Among them, the double-difference pseudorange observation equation can give the pseudorange deviation at the i-th frequency point. floating point valuation

[0150] According to the pseudorange deviation determination method for satellite systems provided in this application, by fixing the ambiguity of the first double-difference wide-lane ambiguity, the second double-difference wide-lane ambiguity, the first double-difference narrow-lane ambiguity, and the second double-difference narrow-lane ambiguity, and considering atmospheric delay, the positioning accuracy is improved. The third double-difference wide-lane ambiguity and the third double-difference narrow-lane ambiguity are searched to achieve ambiguity fixing with a high accuracy rate. This method can realize long-distance estimation of the pseudorange deviation of the receiver observing the first and second satellites, and has a wider range of applications.

[0151] Under normal, unobstructed observation conditions, BDS-3 and BDS-2 satellites are typically evenly distributed over the entire area above the receiver. Furthermore, the correlation of the ionosphere is usually strong within the region. Based on this information, it is assumed that when using the satellite with the highest elevation angle from either BDS-2 or BDS-3 as the reference satellite, the mean values ​​of the double-difference ionospheric delays of all satellites within the BDS-2 and BDS-3 systems should be consistent. Considering the large number of MEO satellites in BDS-3, BDS-3 is selected as the primary reference satellite. First, using the double-difference ionospheric delays extracted from the BDS-3 system as samples, the corresponding mean values ​​are extracted. and standard deviation Then, using the same BDS-3 reference satellite, the double-difference ionospheric delay of all BDS-2 satellites was extracted, and its mean was calculated.

[0152] The following hypotheses are constructed:

[0153]

[0154] Where H0 is the hypothesis, It is the mean of the double-difference ionospheric delay of the first reference satellite q2. H1 is the mean of the double-difference ionospheric delay of the second reference star q3, and H1 is the alternative hypothesis.

[0155] The null hypothesis is that the mean of the double-difference ionosphere is the same for BDS-2 and BDS-3, and the alternative hypothesis is that the mean of the double-difference ionosphere is different for BDS-2 and BDS-3. Assuming that the population double-difference ionospheric delay of the BDS-3 sample follows a normal distribution, the above hypotheses are tested using a t-test:

[0156]

[0157] in, and s1 and s2 are the means of the two samples, s1 and s2 are the standard deviations of the two samples, and n1 and n2 are the sizes of the two samples. The degrees of freedom v of this test are:

[0158]

[0159] Based on the calculated t-test result and degrees of freedom v, the t-distribution can be used to find the p-value. If the p-value ≤ α (usually α is 0.05), the null hypothesis is rejected, indicating a significant difference between the means of the two groups. If the p-value > α, the null hypothesis is not rejected, indicating no significant difference between the means of the two groups. Considering that paths with lower elevation angles have longer propagation paths and higher noise, the cutoff elevation angle of the double-difference ionospheric group can be increased to ensure the validity of the data. Since ionospheric error is strongly correlated with signal propagation path, the ionospheric errors of adjacent paths are usually quite similar. Therefore, further confirmation can be made based on the double-difference ionospheric delay of adjacent paths. However, in actual constellation design, two satellites in the same constellation are avoided from maintaining a constant collinearity; therefore, this method can only be used as a further confirmation option.

[0160] In some embodiments, the target atmospheric delay includes a target double-difference ionospheric delay and a target tropospheric delay. Substituting the target atmospheric delay into the double-difference pseudorange observation equation to obtain the target pseudorange bias of the satellite system includes:

[0161] Substituting the target double-difference ionospheric delay and the target tropospheric delay into the double-difference pseudorange observation equation, we obtain the pseudorange bias estimates for the first satellite and the second satellite;

[0162] The pseudorange bias estimate is smoothed over multiple epochs to obtain the target pseudorange bias.

[0163] It is understandable that obtaining accurate target double-difference ionospheric delay between the first satellite BDS-2 and the second satellite BDS-3 is necessary. and target tropospheric delay Then, substituting into the double-difference pseudorange observation equation, the pseudorange bias can be obtained. pseudorange bias estimator

[0164] In this embodiment, due to the influence of pseudorange noise, it is necessary to estimate the pseudorange bias. Multi-epoch smoothing is necessary to obtain a more accurate estimate of the target pseudorange bias.

[0165] The pseudorange deviation determination method for a satellite system provided in this application can be executed by a pseudorange deviation determination device for the satellite system. This application uses the pseudorange deviation determination device of the satellite system executing the pseudorange deviation determination method as an example to illustrate the pseudorange deviation determination device for the satellite system provided in this application.

[0166] This application also provides a pseudorange deviation determination device for a satellite system.

[0167] like Figure 3As shown, the pseudorange deviation determination device of the satellite system includes: an acquisition module 310, a first processing module 320, a second processing module 330, a third processing module 340, and a fourth processing module 350.

[0168] The acquisition module 310 is used to acquire the observation signal of the receiver, so as to determine the first double-difference wide-lane ambiguity between the first satellite and the first reference satellite, the second double-difference wide-lane ambiguity between the second satellite and the second reference satellite, the first double-difference narrow-lane ambiguity between the first satellite and the first reference satellite, and the second double-difference narrow-lane ambiguity between the first reference satellite and the second reference satellite based on the observation signal.

[0169] The first processing module 320 is used to fix the ambiguity of the first double-difference wide-lane ambiguity, the second double-difference wide-lane ambiguity, the first double-difference narrow-lane ambiguity and the second double-difference narrow-lane ambiguity, determine the atmospheric delay of the satellite system, and the third double-difference wide-lane ambiguity and the third double-difference narrow-lane ambiguity between the first reference satellite and the second reference satellite.

[0170] The second processing module 330 is used to search for the third double-difference wide-lane ambiguity based on the atmospheric delay to determine the wide-lane ambiguity value between the first satellite and the second satellite, and to search for the third double-difference narrow-lane ambiguity to determine the narrow-lane ambiguity value between the first satellite and the second satellite.

[0171] The third processing module 340 is used to obtain the target atmospheric delay between the first satellite and the second satellite based on the wide-lane ambiguity value and the narrow-lane ambiguity value.

[0172] The fourth processing module 350 is used to substitute the target atmospheric delay into the double-difference pseudorange observation equation to obtain the target pseudorange deviation of the satellite system.

[0173] The pseudorange deviation determination device for a satellite system provided in this application fixes the ambiguity of the first double-difference wide-lane ambiguity, the second double-difference wide-lane ambiguity, the first double-difference narrow-lane ambiguity, and the second double-difference narrow-lane ambiguity, taking atmospheric delay into account to improve positioning accuracy. It also searches for the third double-difference wide-lane ambiguity and the third double-difference narrow-lane ambiguity to achieve ambiguity fixation with a high accuracy rate. This device can estimate the pseudorange deviation of the first and second satellites observed by the long-distance receiver, and has a wider range of applications.

[0174] The pseudorange deviation determination device for the satellite system in this application embodiment can be an electronic device or a component within an electronic device, such as an integrated circuit or a chip. The electronic device can be a terminal or other devices besides a terminal. For example, the electronic device can be a mobile phone, tablet computer, laptop computer, PDA, in-vehicle electronic device, mobile internet device (MID), augmented reality (AR) / virtual reality (VR) device, robot, wearable device, ultra-mobile personal computer (UMPC), netbook, or personal digital assistant (PDA), etc. It can also be a server, network attached storage (NAS), personal computer (PC), television (TV), ATM, or self-service machine, etc. This application embodiment does not specifically limit the specific device.

[0175] The pseudorange deviation determination device for the satellite system in this embodiment can be a device with an operating system. This operating system can be Android, iOS, or other possible operating systems; this embodiment does not specifically limit its use.

[0176] The pseudorange deviation determination device for satellite systems provided in this application embodiment can achieve... Figures 1 to 2 The various processes implemented in the method embodiment for determining pseudorange deviation of a satellite system will not be described again here to avoid repetition.

[0177] In some embodiments, such as Figure 4 As shown, this application embodiment also provides an electronic device 400, including a processor 401, a memory 402, and a computer program stored in the memory 402 and executable on the processor 401. When the program is executed by the processor 401, it implements the various processes of the above-described satellite system pseudorange deviation determination method embodiment and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0178] It should be noted that the electronic devices in the embodiments of this application include the mobile electronic devices and non-mobile electronic devices described above.

[0179] This application also provides a non-transitory computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it implements the various processes of the above-described satellite system pseudorange deviation determination method embodiment and achieves the same technical effect. To avoid repetition, it will not be described again here.

[0180] The processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0181] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the pseudorange deviation determination method for the satellite system described above.

[0182] The processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0183] This application embodiment also provides a chip, which includes a processor and a communication interface. The communication interface and the processor are coupled. The processor is used to run programs or instructions to implement the various processes of the above-described satellite system pseudorange deviation determination method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0184] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0185] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0186] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a computer software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, or network device, etc.) to execute the pseudorange deviation determination method of the satellite system of the various embodiments of this application.

[0187] In the description of this application, "first feature" and "second feature" may include one or more of the features.

[0188] In the description of this application, "multiple" means two or more.

[0189] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

[0190] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0191] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for determining pseudorange bias in a satellite system, characterized in that, The satellite system includes a first satellite, a first reference satellite for the first satellite, a second satellite, and a second reference satellite for the second satellite, as well as a base station and a rover station for observing the first satellite, the second satellite, the first reference satellite, and the second reference satellite. The base station and the rover station are equipped with receivers. The method includes: The receiver acquires the observation signal to determine, based on the observation signal, a first double-difference wide-lane ambiguity between the first satellite and the first reference satellite, a second double-difference wide-lane ambiguity between the second satellite and the second reference satellite, a first double-difference narrow-lane ambiguity between the first satellite and the first reference satellite, and a second double-difference narrow-lane ambiguity between the first reference satellite and the second reference satellite. The ambiguity of the first double-difference wide-lane ambiguity, the second double-difference wide-lane ambiguity, the first double-difference narrow-lane ambiguity, and the second double-difference narrow-lane ambiguity is fixed to determine the atmospheric delay of the satellite system, as well as the third double-difference wide-lane ambiguity and the third double-difference narrow-lane ambiguity between the first reference satellite and the second reference satellite. Based on the atmospheric delay, the third double-difference wide-lane ambiguity is searched to determine the wide-lane ambiguity value between the first satellite and the second satellite, and the third double-difference narrow-lane ambiguity is searched to determine the narrow-lane ambiguity value between the first satellite and the second satellite. Based on the wide-lane ambiguity value and the narrow-lane ambiguity value, the target atmospheric delay between the first satellite and the second satellite is obtained; Substituting the target atmospheric delay into the double-difference pseudorange observation equation, the target pseudorange bias of the satellite system is obtained.

2. The pseudorange deviation determination method for a satellite system according to claim 1, characterized in that, The step of searching for the third double-difference wide-lane ambiguity based on the atmospheric delay to determine the wide-lane ambiguity value between the first satellite and the second satellite includes: Based on the floating-point solution of the third double-difference wide-lane ambiguity between the first reference star and the second reference star, the wide-lane search range and the candidate wide-lane integer ambiguities of the third double-difference wide-lane ambiguity are determined. Based on the wide alley search range, the candidate wide alley integer ambiguity is searched, and the deviation degree of the candidate wide alley integer ambiguity is determined. Based on the atmospheric delay, the atmospheric delay difference corresponding to the degree of deviation is calculated, and the wide-lane ambiguity value is determined from the candidate wide-lane integer ambiguities.

3. The method for determining pseudorange deviation of a satellite system according to claim 2, characterized in that, The wide alley search range is: Where floor(·) and ceil(·) are floor down and floor up respectively, and WL(·) represents the wide alley combination of the pseudo-millimeter part. The third double-difference wide-lane ambiguity; The pseudorange deviation between the first satellite and the second satellite at the first frequency point. λ represents the pseudorange deviation between the first and second satellites at the second frequency point. wl denoted as the wide-lane wavelength of the satellite system.

4. The method for determining pseudorange deviation of a satellite system according to claim 1, characterized in that, The third double-difference wide-lane ambiguity and the third double-difference narrow-lane ambiguity are obtained based on the following steps: The first double-difference wide-lane ambiguity and the second double-difference wide-lane ambiguity are differentially analyzed to obtain the third double-difference wide-lane ambiguity; The third double-difference narrow alley ambiguity is obtained by differentiating the first double-difference narrow alley ambiguity and the second double-difference narrow alley ambiguity.

5. The method for determining pseudorange deviation of a satellite system according to claim 4, characterized in that, The double-difference pseudorange observation equation is: In the formula, E{·} represents taking the expectation. It is the pseudorange observation value of the first satellite at the i-th frequency point minus the model prior value of the observed prior pseudorange residual. It is the pseudorange observation value of the second satellite at the i-th frequency point minus the model prior value of the observed prior pseudorange residual. It is the phase observation value of the first satellite at the i-th frequency point minus the observed value of the model prior value, which is the prior phase residual. It is the phase observation value of the second satellite at the i-th frequency point minus the observed value of the model prior value, which is the prior phase residual. It is the clock bias of the GNSS receiver. It is the amplification factor of the ionosphere at the i-th frequency point. It is the ionospheric error experienced in the observations of the first satellite. This refers to the ionospheric error in the observations from the second satellite. It is the projection coefficient of the first satellite's troposphere. It is the projection coefficient of the second satellite's troposphere. It is the pseudorange hardware delay error between the satellite end and the receiver end in the first satellite observation. It is the pseudorange hardware delay error between the satellite end and the receiver end in the second satellite observation. These are the ambiguity parameters of the first satellite. This is the ambiguity parameter of the second satellite, T. r and T b These are the tropospheric parameters for the rover r and the base station b, respectively. and The tropospheric parameters T for the rover r and the base station b r and T b The corresponding projection function; This represents the difference in pseudorange deviation between the first satellite and the second satellite.

6. The method for determining pseudorange deviation of a satellite system according to claim 1, characterized in that, When the observed signal includes the wide-lane wavelength of the satellite system, the double-difference phase and pseudorange observations of the first satellite and the first reference satellite, and the frequency value, the formula for calculating the first double-difference wide-lane ambiguity is as follows: In the formula, s is the satellite identifier. λ is the first double-difference wide-lane ambiguity between the first satellite BDS-2 and the first reference satellite q2 calculated based on the rover r and the base station b. wl The first double-difference wide-lane ambiguity The corresponding wide-lane wavelength; The phase difference is based on the i-th frequency point of the first satellite BDS-2 and the first reference satellite q2 at the rover station r and the base station b. For pseudorange observations at the i-th frequency point of the first satellite BDS-2 and the first reference satellite q2 based on the rover r and the base station b, where i (i = 1, 2, 3) is the frequency number of the frequency point, f i Let be the frequency value of the i-th (i = 1, 2, 3) frequency point.

7. The method for determining pseudorange deviation of a satellite system according to claim 1, characterized in that, The target atmospheric delay includes the target double-difference ionospheric delay and the target tropospheric delay. Substituting the target atmospheric delay into the double-difference pseudorange observation equation yields the target pseudorange bias of the satellite system, including: Substituting the target double-difference ionospheric delay and the target tropospheric delay into the double-difference pseudorange observation equation, we obtain the pseudorange bias estimates for the first satellite and the second satellite; The pseudorange bias estimate is smoothed over multiple epochs to obtain the target pseudorange bias.

8. A pseudorange deviation determination device for a satellite system, characterized in that, The satellite system includes a first satellite, a first reference satellite for the first satellite, a second satellite, and a second reference satellite for the second satellite, as well as a base station and a rover station for observing the first satellite, the second satellite, the first reference satellite, and the second reference satellite. The base station and the rover station are equipped with receivers. The device includes: The acquisition module is used to acquire the observation signal of the receiver, so as to determine the first double-difference wide-lane ambiguity between the first satellite and the first reference satellite, the second double-difference wide-lane ambiguity between the second satellite and the second reference satellite, the first double-difference narrow-lane ambiguity between the first satellite and the first reference satellite, and the second double-difference narrow-lane ambiguity between the first reference satellite and the second reference satellite based on the observation signal. The first processing module is used to fix the ambiguity of the first double-difference wide-lane ambiguity, the second double-difference wide-lane ambiguity, the first double-difference narrow-lane ambiguity and the second double-difference narrow-lane ambiguity, determine the atmospheric delay of the satellite system, and the third double-difference wide-lane ambiguity and the third double-difference narrow-lane ambiguity between the first reference satellite and the second reference satellite. The second processing module is used to search for the third double-difference wide-lane ambiguity based on the atmospheric delay to determine the wide-lane ambiguity value between the first satellite and the second satellite, and to search for the third double-difference narrow-lane ambiguity to determine the narrow-lane ambiguity value between the first satellite and the second satellite. The third processing module is used to obtain the target atmospheric delay between the first satellite and the second satellite based on the wide-lane ambiguity value and the narrow-lane ambiguity value; The fourth processing module is used to substitute the target atmospheric delay into the double-difference pseudorange observation equation to obtain the target pseudorange deviation of the satellite system.

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 program, it implements the pseudorange deviation determination method for the satellite system as described in any one of claims 1-7.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the pseudorange deviation determination method for a satellite system as described in any one of claims 1-7.

Images