A satellite navigation receiver signal processing method and system

Abstract

The application discloses a satellite navigation receiver signal processing method and system, and belongs to the technical field of satellite navigation. The method comprises the following steps: step 1, initializing the satellite navigation receiver, and establishing a communication link between the satellite navigation receiver and an RTK reference station; step 2, processing received satellite signals by the satellite navigation receiver to obtain satellite ephemeris parameters; then combining the received reference station data to form basic data; step 3, constructing a carrier phase double difference prediction model and a code phase prediction model, combining the basic data, respectively calculating local carrier signal control quantities and local code signal control quantities, and writing the control quantities into a digital control oscillator; and step 4, performing position solving, updating a satellite navigation receiver predicted position by using a new position obtained by solving, and feeding back to step 3 to form a closed loop control of position solving assisted signal tracking. The application can realize high-precision and continuous signal tracking in a complex environment.

Description

Technical Field

[0001] This invention belongs to the field of satellite navigation technology, and specifically relates to a signal processing method and system for a satellite navigation receiver. Background Technology

[0002] The performance indicators of a satellite navigation receiver include: high dynamic range, weak signal handling, and high accuracy. The baseband signal processing stage of a satellite navigation receiver includes signal acquisition, tracking, and positioning calculation. After signal acquisition, except in cases of loss-of-lock re-acquisition, the tracking loop continuously tracks the signal and outputs carrier phase and pseudorange information. Signal tracking performance largely determines the overall performance of the satellite navigation receiver.

[0003] With the increasing demand for high-precision positioning, technologies such as carrier phase differential positioning (RTK) and precise point positioning (PPP) have developed rapidly. Among these, differential technology is the core means of achieving high precision in RTK, specifically including:

[0004] (1) Single Difference (SD): By subtracting data between satellites or receivers, it is mainly used to eliminate satellite clock errors or receiver clock errors;

[0005] (2) Double Difference (DD): By further subtracting the data from two satellites and two receivers, satellite clock errors, receiver clock errors, and some orbital and ionospheric errors can be eliminated simultaneously.

[0006] While such methods can improve accuracy, the original carrier phase measurement error and the occurrence of cycle slips still depend on the receiver tracking loop itself. Existing satellite navigation receivers exhibit unstable carrier phase tracking or even difficulty in continuous locking under weak signal, high dynamic, or partially obstructed environments. Summary of the Invention

[0007] Based on the above-mentioned technical problems, this invention proposes a signal processing method for satellite navigation receivers. This method introduces high-precision information from RTK reference stations into the receiver tracking loop by constructing a prediction model and directly controls the local code and carrier oscillator using double-difference geometric constraints, thereby achieving high-precision, continuous signal tracking in complex environments.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A satellite navigation receiver signal processing method includes the following steps:

[0010] Step 1: Initialize the satellite navigation receiver and establish a communication link between the satellite navigation receiver and the RTK base station; the satellite navigation receiver begins to receive base station data sent by the RTK base station;

[0011] Step 2: The satellite navigation receiver acquires, tracks, and decodes the received satellite signals and navigation messages to obtain satellite ephemeris parameters; then, it combines these parameters with the base station data received in Step 1 to form basic data.

[0012] Step 3: Construct a carrier phase double-difference prediction model and a code phase prediction model. Calculate the local carrier signal control quantity and the local code signal control quantity using the basic data from Step 2, and write the local carrier signal control quantity and the local code signal control quantity into the digital control oscillator.

[0013] Step 4: After Step 3 is completed, position calculation is performed. The new position obtained from the calculation is used to update the estimated position of the satellite navigation receiver, and the new position is fed back to Step 3 to form a closed-loop control for position calculation-assisted signal tracking.

[0014] Furthermore, based on the satellite navigation receiver signal processing method, this invention also proposes a corresponding satellite navigation receiver signal processing system, which adopts the following scheme:

[0015] A satellite navigation receiver signal processing system includes the following modules:

[0016] The initialization module is used to initialize the satellite navigation receiver and establish a communication link between the satellite navigation receiver and the RTK base station.

[0017] The data processing module is used by the satellite navigation receiver to acquire, code and carrier track, and decode navigation messages of received satellite signals to obtain satellite ephemeris parameters; and to process the data into basic data by combining the data from the reference station received by the satellite navigation receiver.

[0018] The signal control quantity calculation module is used to construct the carrier phase double-difference prediction model and the code phase prediction model. It calculates the local carrier signal control quantity and the local code signal control quantity using basic data and writes them into the digital control oscillator.

[0019] It also includes a position calculation and status update module, which performs position calculation and uses the new position obtained from the calculation to update the estimated position of the satellite navigation receiver. The new position is then fed back to the signal control quantity calculation module to form a closed-loop control for position calculation to assist signal tracking.

[0020] Compared with the prior art, the present invention has the following beneficial technical effects:

[0021] First, it significantly improves tracking sensitivity and continuity in weak signal environments. This invention employs a vector processing architecture, utilizing observation information from strong-signal satellites (reference satellites) within the visible range as anchor points. Combined with high-precision position feedback, it performs vector-based coordinated tracking (i.e., using strong signals to assist weak signals) on blocked or attenuated weak signal channels. This allows the receiver to maintain channel lock even when some satellite signals are extremely weak, avoiding the problem of lock loss common in traditional independent loops.

[0022] Second, it eliminates errors at the physical level, reducing tracking jitter. Traditional vector loops typically require estimating complex receiver clock biases, while this invention directly introduces a double-difference model within the tracking loop, namely a carrier phase double-difference prediction model and a code phase prediction model. This model physically eliminates the influence of receiver clock bias and satellite clock bias, making the control input of the digitally controlled oscillator (NCO) purely dependent on the geometric distance change between the receiver and the satellite. This pure geometric control significantly reduces noise caused by inaccurate clock bias estimation, substantially reducing phase tracking jitter.

[0023] Third, the design of the code loop is simplified, achieving code phase alignment without clock bias assistance. This invention utilizes the measured pseudorange of a reference satellite for geometric projection to control the code loops of other channels. This method achieves code loop alignment without clock bias vector assistance, eliminating the need for the receiver to design complex delay-locked loops (DLLs) for each channel to maintain high-precision code phase alignment. This not only reduces computational complexity but also improves the multipath resistance of code tracking.

[0024] Fourth, it forms a positive closed-loop gain for "tracking-positioning". This invention moves differential assistance forward to the signal tracking stage, enabling the receiver to output more continuous carrier phase observations with fewer cycle slips. These high-quality raw observations, in turn, improve the success rate of RTK ambiguity fixing and the continuity of positioning, thus forming a virtuous closed-loop system of "high-precision positioning assists signal tracking, and high-quality observations feed back into high-precision positioning". Attached Figure Description

[0025] Figure 1 This is a flowchart of the satellite navigation receiver signal processing method of the present invention;

[0026] Figure 2 This is a schematic diagram of the signal processing system of the satellite navigation receiver of the present invention. Detailed Implementation

[0027] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0028] Example 1:

[0029] This invention proposes a signal processing method for satellite navigation receivers, namely a dual-difference vector phase-locked loop (DD-VPLL) signal processing method assisted by RTK reference station information. Its core idea lies in changing the traditional receiver's cascaded mode of "independent tracking first, then differential positioning," by moving the "dual-difference positioning model" forward into the signal tracking loop. Utilizing the high-precision observations of the reference station and the dual-difference geometric constraints, the numerically controlled oscillator (NCO) input of the local code and carrier is directly calculated, thereby achieving robust signal tracking in weak signal or high dynamic environments. This invention aims to improve the receiver's carrier phase tracking performance and positioning continuity in high dynamic, signal-obstructed, and weak signal environments through deep integration of baseband signal processing and RTK positioning algorithms, without relying on inertial auxiliary devices.

[0030] The research idea of ​​this invention is to change the traditional unidirectional flow of "observation-solution" into a closed-loop flow of "observation-solution-prediction-control".

[0031] like Figure 1 As shown, a satellite navigation receiver signal processing method includes the following steps:

[0032] Step 1: System initialization;

[0033] Initialize the satellite navigation receiver and RTK differential system, establishing a communication or data link between the satellite navigation receiver and the base station (or CORS network) in the RTK differential system. The satellite navigation receiver begins receiving base station data transmitted by the RTK base station, including base station carrier phase observations. and base station coordinate information .

[0034] Step 2: Preprocessing and Information Acquisition;

[0035] Before entering high-precision tracking mode, the receiver uses conventional methods (such as cold start acquisition) to initially track the satellite signal and decodes the navigation message to obtain satellite ephemeris parameters. That is, the satellite navigation receiver acquires the received satellite signal, performs code and carrier tracking, and decodes the navigation message to obtain satellite ephemeris parameters. At this point, the receiver has all the basic data (satellite position, base station data, approximate local position) required for double-difference calculation.

[0036] Step 3: Dual-difference vector tracking (DD-VPLL core control generation);

[0037] This is the core innovation of this invention. This method no longer relies on traditional phase detector feedback to independently adjust each channel, but instead directly calculates the NCO control quantity based on geometric relationships. This involves two parallel paths:

[0038] Construct a carrier phase double-difference prediction model and a code phase prediction model. Calculate the local carrier signal control quantity and the local code signal control quantity using the basic data in step 2, and write the local carrier signal control quantity and the local code signal control quantity into the digitally controlled oscillator.

[0039] Specifically, based on the local receiver's estimated position and satellite ephemeris parameters, combined with the carrier phase observations from the reference station, a reference satellite is selected to construct a double-difference observation model. Local signal control quantities are then calculated and written into the digitally controlled oscillator (NCO). Carrier control utilizes the double-difference carrier phase model to eliminate receiver clock errors and atmospheric errors, calculates local carrier frequency control quantities, and achieves vector prediction tracking of weak signal carrier phases. Code control uses the reference satellite's observation information, combined with geometric distance projection, to calculate local code signal control quantities, achieving clock-bias-free assisted tracking of the code phase.

[0040] More specifically, the calculation steps for the local carrier signal control quantity are as follows:

[0041] Step S311: Determine the reference satellite and acquire base station information;

[0042] The receiver first selects the optimal satellite from the visible satellites as the reference satellite based on the elevation angle and carrier-to-noise ratio (C / N0). The remaining satellites are non-reference satellites (denoted as...). Simultaneously acquire the same moment. RTK reference station carrier phase observations of the reference satellite and carrier phase observations of non-reference satellites .

[0043] Step S312: Construct a carrier phase double-difference prediction model;

[0044] Using the double-difference principle to eliminate receiver clock bias and atmospheric error, the calculation of the rover station (satellite navigation receiver) for the first... Carrier phase prediction values ​​of satellites The calculation formula for the carrier phase double-difference prediction model is as follows:

[0045] ;

[0046] in: The reference satellite carrier phase obtained for the local tracking loop; For the reference station to receive the first The specific time of the non-reference satellite signal Measured carrier phase observations; The specific time at which the reference station receives the reference satellite signal Measured carrier phase observations; The carrier frequency of the satellite signal; For the satellite navigation receiver's reception time, and The RTK base station received the first The timing of signals from the individual satellite and the reference satellite; The term includes initial phase deviation and integer ambiguity terms, where and For local satellite navigation receivers targeting the first The initial phase deviation between the satellite and the reference satellite, and These are RTK base stations for reference satellites and the first... The initial phase deviation of the satellite.

[0047] For any visible satellite Using the high-precision receiver position estimated in the previous moment Based on the observations from the base station, the above double-difference equation is constructed. This equation is then used to inversely deduce the carrier phase that the receiver should receive. This prediction eliminates receiver clock bias, satellite clock bias, and most ionospheric / tropospheric errors. The predicted phase is then converted into frequency control and directly written into the channel. The carrier NCO. This makes it possible even if the satellite Even with extremely weak signals, the local carrier can accurately reproduce the phase changes of the input signal.

[0048] Step S313: Calculate the geometric distance double-difference correction term and carrier frequency control quantity;

[0049] Considering the changes in light propagation delay and geometric distance, a geometric distance correction term is introduced to modify the carrier phase double-difference prediction model constructed in S312, resulting in the phase input of the local carrier digitally controlled oscillator (NCO):

[0050] ;

[0051] in: The carrier wavelength; For the phase input of the local carrier digitally controlled oscillator; The reference satellite carrier phase observation value is the actual measured value of the local tracking loop; For RTK base station to the first Carrier phase observations of one satellite (not a reference satellite); The carrier phase observations of the reference satellite from the RTK base station; This is the double-difference residual error term (including atmospheric errors such as those from the troposphere and ionosphere that were not completely eliminated, as well as system noise).

[0052] The double-difference geometric distance term is calculated by the following formula:

[0053] ;

[0054] in: Estimate the position for the local satellite navigation receiver. For the known location of the RTK base station, For the first The spatial coordinates of the satellite at the moment of signal transmission. The spatial coordinates of the selected reference satellite at the time of signal transmission.

[0055] Using the aforementioned phase input (or predicted phase) Feedforward control is applied to the local carrier digitally controlled oscillator, combined with the residual output of the phase detector. Adjust carrier frequency :

[0056] ;

[0057] in: This is the intermediate frequency. For the loop update cycle, This is the value of the carrier phase detector; and These are the current epoch times. and the previous epoch The calculated local carrier phase input.

[0058] The calculation steps for the local code signal control quantity are as follows (based on geometric projection):

[0059] Step S321: Obtain base station pseudorange and calculate clock error recovery term;

[0060] Since the carrier phase double-difference prediction model in step S312 eliminates the receiver clock bias, and code tracking needs to track the actual signal arrival time (including the clock bias), it is necessary to use a reference satellite ( Using as the anchor point, estimate the current receiver clock bias.

[0061] Calculate the single-difference pseudorange residual of the reference satellite as the clock error recovery term. :

[0062] ;

[0063] in: The reference satellite pseudorange is measured in the local code loop. Reference satellite pseudorange for synchronous observations at the RTK base station; The single-difference geometric distance for the reference satellite (using S313) and calculate).

[0064] This item It includes the clock bias of the receiver relative to the base station and the residual error of the reference satellite that was not modeled.

[0065] Step S322: Construct a code phase (pseudorange) prediction model;

[0066] Using the double-difference geometric distance term calculated in S313 Combining base station pseudorange and clock bias recovery terms, predict the first... pseudorange of a non-reference satellite .

[0067] ;

[0068] in: For RTK base station to the first Measured pseudorange of a non-reference satellite; For the double-difference geometric distance term, the calculation result of step S313 is directly used (using the high-precision geometric changes of the carrier to drive the code ring).

[0069] Traditional VDFLL only uses Doppler (velocity) assistance, while this invention uses base station pseudorange (absolute position) + dual-difference carrier geometry (high-precision variation) assistance, which can greatly resist multipath.

[0070] To prevent code loop loss of lock, this invention does not rely on a traditional Delay-Locked Loop (DLL) for independent tracking, but instead utilizes a projection method. This method uses an internal backup scalar loop (STL) to stably track a reference satellite. Due to the reference satellite and the target satellite By sharing the same receiver clock bias and utilizing the high-precision geometric distance difference calculated in Path 1, the pseudorange of the reference satellite can be "projected" onto the target satellite. The calculated... Directly used for control channels The code NCO is used. This method ensures that the code phase of all channels is strictly synchronized with the reference satellite, eliminating the interference of receiver clock instability on weak signal code tracking.

[0071] Step S323: Code loop error calculation and NCO control;

[0072] The difference between the predicted pseudorange and the local pseudorange is calculated as feedforward compensation.

[0073] (1) Calculate the auxiliary error compensation amount ;

[0074] ;

[0075] in: The speed of light is used; convert it to time / chip units. The output of the local tracking loop at the current moment is the first... Measured pseudorange of a non-reference satellite.

[0076] (2) Calculate the final code NCO control quantity;

[0077] Combining carrier-assisted (Doppler scaling) and pseudorange prediction-assisted (phase alignment), calculate the local code signal control quantity:

[0078] ;

[0079] in: For the first The carrier frequency control value for each satellite channel, i.e., the high-precision carrier frequency calculated in step S313. For nominal code frequency, The nominal carrier frequency, For the transfer function operator of the loop filter, The original error output by the code phase detector. This is the calculated auxiliary error compensation amount.

[0080] Step 4: High-precision position calculation and state update;

[0081] After step 3 is completed, the observed values ​​output by the loop tracking are combined with the base station information, and a high-precision position calculation is performed using the double-difference observation equation. The new position obtained from the calculation is used to update the local receiver's estimated position, and this new position is fed back to step 3, forming a closed-loop control for position calculation-assisted signal tracking.

[0082] In other words, driven by the aforementioned control variables, each channel NCO performs correlation operations with the input signal, outputting relevant I / Q branch data and residuals. The navigation processor then uses these new observations, combined with base station data, to solve the double-difference positioning equation again and update the receiver position. This updated position will be used for prediction in the next epoch (step 3), thus forming a closed-loop vector tracking.

[0083] More specifically, during high-precision position calculation, the observed values ​​output by the loop tracking include the local carrier phase output after closed-loop tracking of each channel's NCO. With pseudo-distance The reference station information includes the reference station carrier phase. Base station pseudorange and base station coordinates A double-difference positioning model is used to construct a double-difference observation equation. The local observations and base station information are then substituted into the equation to calculate the position, resulting in the updated high-precision predicted position of the local receiver. .

[0084] In summary, this invention constructs a dual-difference vector phase-locked loop (DD-VPLL) architecture, introduces high-precision information from the RTK reference station into the receiver tracking loop, and directly controls the local code and carrier oscillator using dual-difference geometric constraints, thereby achieving high-precision, continuous signal tracking in complex environments.

[0085] Example 2:

[0086] Figure 2 This is a schematic diagram of the system structure of an embodiment of the present invention. The present invention can be implemented using this system, but is not limited thereto. Figure 2 The system shown. The entire system includes: a satellite navigation receiver, an RTK reference station or a CORS station.

[0087] Furthermore, this embodiment 2 describes a satellite navigation receiver signal processing system, which is based on the same inventive concept as the satellite navigation receiver signal processing method described in embodiment 1 above.

[0088] A satellite navigation receiver signal processing system includes the following modules:

[0089] The initialization module is used to initialize the satellite navigation receiver and establish a communication link between the satellite navigation receiver and the RTK base station.

[0090] The data processing module is used by the satellite navigation receiver to acquire, code and carrier track, and decode navigation messages of received satellite signals to obtain satellite ephemeris parameters; and to process the data into basic data by combining the data from the reference station received by the satellite navigation receiver.

[0091] The signal control quantity calculation module is used to construct the carrier phase double-difference prediction model and the code phase prediction model. It calculates the local carrier signal control quantity and the local code signal control quantity using basic data and writes them into the digital control oscillator.

[0092] It also includes a position calculation and status update module, which performs position calculation and uses the new position obtained from the calculation to update the estimated position of the satellite navigation receiver. The new position is then fed back to the signal control quantity calculation module to form a closed-loop control for position calculation to assist signal tracking.

[0093] It should be noted that the implementation process of the functions and roles of each functional module in the satellite navigation receiver signal processing system of this embodiment 2 is detailed in the implementation process of the corresponding steps in the method of embodiment 1 above, and will not be repeated here.

[0094] Example 3:

[0095] This embodiment 3 describes a computer device, which includes a memory and one or more processors. Executable code is stored in the memory. When the processor executes the executable code, it implements the satellite navigation receiver signal processing method described in embodiment 1 above.

[0096] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A signal processing method for a satellite navigation receiver, characterized in that, Includes the following steps: Step 1: Initialize the satellite navigation receiver and establish a communication link between the satellite navigation receiver and the RTK base station; The satellite navigation receiver begins receiving base station data transmitted by the RTK base station; Step 2: The satellite navigation receiver acquires, tracks, and decodes the received satellite signals and navigation messages to obtain satellite ephemeris parameters; then, it combines these parameters with the base station data received in Step 1 to form basic data. Step 3: Construct a carrier phase double-difference prediction model and a code phase prediction model. Calculate the local carrier signal control quantity and the local code signal control quantity using the basic data from Step 2, and write the local carrier signal control quantity and the local code signal control quantity into the digital control oscillator. Step 4: After Step 3 is completed, position calculation is performed. The new position obtained from the calculation is used to update the estimated position of the satellite navigation receiver, and the new position is fed back to Step 3 to form a closed-loop control for position calculation-assisted signal tracking. The calculation steps for the local carrier signal control quantity in step 3 are as follows: Step S311: Based on the satellite elevation angle and carrier-to-noise ratio information, select one satellite from the visible satellites as a reference satellite, denoted as . The remaining satellites are non-reference satellites, denoted as... Simultaneously acquire the same moment RTK reference station carrier phase observations of the reference satellite and carrier phase observations of non-reference satellites ; Step S312: Construct a carrier phase double-difference prediction model and calculate the satellite navigation receiver's prediction for the first... Carrier phase prediction values ​​of satellites The calculation formula for the carrier phase double-difference prediction model is as follows: ； in: The reference satellite carrier phase obtained for the local tracking loop; For the reference station to receive the first The specific time of the satellite signal Measured carrier phase observations; The specific time at which the reference station receives the reference satellite signal Measured carrier phase observations; The carrier frequency of the satellite signal; For the satellite navigation receiver's reception time, and The RTK base station received the first The timing of signals from the individual satellite and the reference satellite; and For satellite navigation receivers targeting the first The initial phase deviation between the satellite and the reference satellite, and These are RTK base stations for reference satellites and the first... The initial phase deviation of the satellite; Step S313: Considering the changes in light propagation delay and geometric distance, a geometric distance correction term is introduced to correct the carrier phase double-difference prediction model constructed in S312, resulting in the phase input of the local carrier digitally controlled oscillator: ； in: The carrier wavelength; For the phase input of the local carrier digitally controlled oscillator; The reference satellite carrier phase observations are measured using the local tracking loop. For RTK base station to the first Carrier phase observations of the satellites, The carrier phase observations of the reference satellite from the RTK base station. This is the double-difference residual error term; The double-difference geometric distance term is calculated by the following formula: ； in: Estimate the position for the local satellite navigation receiver. For the known location of the RTK base station, For the first The spatial coordinates of the satellite at the moment of signal transmission. The reference satellite's spatial coordinates at the time of signal transmission; Using the above phase input quantity Feedforward control is applied to the local carrier digitally controlled oscillator, combined with the residual output of the phase detector. Adjust carrier frequency : ； in: This is the intermediate frequency. For the loop update cycle, This is the value of the carrier phase detector. For the current epoch The calculated local carrier phase input quantity, For the previous epoch The calculated local carrier phase input.

2. The satellite navigation receiver signal processing method according to claim 1, characterized in that, In step 1: the reference station data includes the reference station carrier phase observation value and the reference station coordinate information.

3. The satellite navigation receiver signal processing method according to claim 1, characterized in that, The calculation steps for the local code signal control quantity in step 3 are as follows: Step S321: Calculate the single-difference pseudorange residual of the reference satellite as the clock error recovery term. ; ； in: The reference satellite pseudorange is measured in the local code loop. Reference satellite pseudorange for synchronous observations at the RTK base station; The single-difference geometric distance is used as a reference satellite; Step S322: Construct a code phase prediction model to predict the first... pseudorange of a non-reference satellite ; ； in: For RTK base station to the first Measured pseudorange of a non-reference satellite; This is the double-difference geometric distance term; Step S323: Calculate the auxiliary error compensation amount ; ； in: The speed of light is used; convert it to time / chip units. The output of the local tracking loop at the current moment is the first... Measured pseudorange of the satellite; Combining carrier-assisted and pseudorange prediction-assisted methods, calculate the local code signal control quantity: ； in: For the first The carrier frequency of each satellite channel For nominal code frequency, The nominal carrier frequency, For the transfer function operator of the loop filter, This represents the original error output by the code phase detector. This is the calculated auxiliary error compensation amount.

4. The satellite navigation receiver signal processing method according to claim 3, characterized in that, In step 4: the observed values ​​output by the loop tracking are combined with the base station information, and the position is calculated using the double-difference observation equation; The observed values ​​output by the loop tracking include the local carrier phase and pseudorange output by the digitally controlled oscillator of each channel after closed-loop tracking; the reference station information includes the reference station carrier phase observed values, reference station pseudorange, and reference station coordinates; a double-difference observation equation is constructed using a double-difference positioning model, and the observed values ​​output by the loop tracking and the reference station information are substituted into the double-difference observation equation to calculate the position and obtain the updated estimated position of the satellite navigation receiver.

5. A satellite navigation receiver signal processing system, characterized in that, The satellite navigation receiver signal processing method as described in any one of claims 1-4 includes the following modules: The initialization module is used to initialize the satellite navigation receiver and establish a communication link between the satellite navigation receiver and the RTK base station. The data processing module is used by the satellite navigation receiver to acquire, code and carrier track, and decode navigation messages of received satellite signals to obtain satellite ephemeris parameters; and to process the data into basic data by combining the data from the reference station received by the satellite navigation receiver. The signal control quantity calculation module is used to construct the carrier phase double-difference prediction model and the code phase prediction model. It calculates the local carrier signal control quantity and the local code signal control quantity using basic data and writes them into the digital control oscillator. It also includes a position calculation and status update module, which performs position calculation and uses the new position obtained from the calculation to update the estimated position of the satellite navigation receiver. The new position is then fed back to the signal control quantity calculation module to form a closed-loop control for position calculation to assist signal tracking.

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