Boot zero value calibration method and device, electronic equipment and storage medium
By configuring receivers to share an antenna and clock, and using Doppler values and carrier phase observations for power-on zero-value error compensation, the problem of power-on zero-value synchronization in multi-receiver systems is solved, achieving efficient error calibration and correction.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- AEROSPACE INFORMATION RES INST CAS
- Filing Date
- 2023-05-19
- Publication Date
- 2026-07-21
AI Technical Summary
In multi-receiver systems, the zero-value error at startup between receivers cannot be synchronized, resulting in the inability to eliminate carrier phase observation errors. Existing technologies make it difficult to achieve effective zero-value calibration at startup.
By configuring two receivers to acquire satellite signals using the same antenna and connecting them to the same external clock, zero-value error compensation is performed using Doppler values, pseudorange observations, and complete carrier phase observations. The standard deviation of error compensation is determined by recursion, and gross errors are eliminated by the 3σ principle. The average value is then used for calibration.
It achieves efficient calibration of the zero value at startup among multiple receivers, reduces carrier phase observation error, simplifies hardware environment setup, and reduces algorithm complexity and cost.
Smart Images
Figure CN116840864B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of satellite navigation technology, and in particular to a method, apparatus, electronic device, and storage medium for zero-value calibration upon startup. Background Technology
[0002] With the continuous development of Global Navigation Satellite Systems (GNSS), the manufacturing process of receiver boards has been continuously improved, resulting in a decrease in price and size. This makes it possible to build more sophisticated receiver terminal systems using multiple antennas. Multiple antennas refer to antenna systems arranged according to a certain pattern, with the arrangement pattern strongly correlated with requirements. Multiple antenna systems have been widely used in numerous fields, such as deformation monitoring, high-precision attitude determination, and high-precision positioning. In the GNSS field, multiple antenna systems are widely applied. Using multiple antennas, Real-Time Kinematic (RTK) technology can achieve centimeter-level positioning accuracy in real time. Furthermore, multiple antennas can provide additional baseline constraints, which is beneficial for ambiguity fixation among multiple antennas, improving the success rate of ambiguity fixation and convergence time. Common methods include the long-short baseline method and the virtual baseline method. Multiple antennas are also widely used in multipath effect suppression and spoofing interference detection.
[0003] Achieving collaborative operation among multiple receivers hinges on precise synchronization between them. While frequency synchronization can be achieved by locking onto the same external clock, time synchronization remains challenging. Especially for general receivers, manufacturing limitations lead to time discrepancies in signal sampling by the receiver circuit board. This results in a lack of time synchronization when multiple receivers operate simultaneously, leading to a zero-value calibration problem—meaning multiple receivers cannot acquire observation data at the same moment. The error caused by this zero-value calibration is absorbed by the receiver clock bias, introducing errors into the carrier phase observations. Since the zero-value calibration of each receiver may be inconsistent, this error cannot be eliminated through inter-station calibration. Therefore, achieving zero-value calibration among multiple receivers is a pressing issue that the industry needs to address. Summary of the Invention
[0004] To address the problems existing in the prior art, embodiments of the present invention provide a power-on zero value calibration method, apparatus, electronic device, and storage medium.
[0005] In a first aspect, the present invention provides a method for power-on zero-value calibration, comprising:
[0006] Based on the Doppler values, pseudorange observations, and complete carrier phase observations of the two receivers at each epoch, the first compensation data corresponding to each epoch is determined. The first compensation data is used to characterize the power-on zero error compensation value adopted by the two receivers for each satellite.
[0007] Based on the first compensation data corresponding to each epoch, the standard deviation of the start-up zero value error compensation corresponding to each epoch is determined by recursion.
[0008] Based on the standard deviation of the zero-value error compensation corresponding to each epoch, the first compensation data corresponding to each epoch is removed by the 3σ principle to determine the second compensation data corresponding to each epoch.
[0009] Based on the second compensation data corresponding to each epoch, the power-on zero value error compensation calibration value corresponding to each epoch is determined by averaging. The power-on zero value error compensation calibration value is used to correct the power-on zero value error between the two receivers.
[0010] The two receivers acquire satellite signals through the same antenna and are connected to the same external clock.
[0011] Optionally, according to the power-on zero-value calibration method provided by the present invention, determining the first compensation data corresponding to each epoch based on the Doppler values, pseudorange observations, and complete carrier phase observations of the two receivers at each epoch includes:
[0012] Based on the Doppler values and pseudorange observations of the two receivers at the first epoch, the time difference is calculated using the pseudorange observations and compensation is performed using the Doppler values to determine the second compensation data corresponding to the first epoch. The first epoch can be any epoch.
[0013] Based on the complete carrier phase observations of the two receivers at the first epoch and the second compensation data corresponding to the first epoch, the transmission delay difference is eliminated, and the first compensation data corresponding to the first epoch is determined.
[0014] Optionally, according to the power-on zero-value calibration method provided by the present invention, the step of determining the second compensation data corresponding to the first epoch based on the Doppler values and pseudorange observations of the two receivers at the first epoch, using the pseudorange observations to calculate the time difference and using the Doppler values for compensation, includes:
[0015] Based on the Doppler values and pseudorange observations of the two receivers at the first epoch, the second compensation data corresponding to the first epoch is determined by the following zero-value error compensation formula.
[0016]
[0017] The two receivers include receiver i and receiver j, where c represents the speed of light, and Δt 0,ij (τ) represents the difference between the time deviation of receiver i at the power-on time and the time deviation of receiver j at the power-on time, where τ is the time corresponding to the first epoch, λ represents the satellite signal wavelength, and f d,i (τ) represents the Doppler value of receiver i. This represents the pseudorange observation of receiver i with respect to satellite s at time τ. Let τ represent the pseudorange observation value of receiver j for satellite s at time τ.
[0018] Optionally, according to the power-on zero-value calibration method provided by the present invention, the step of eliminating transmission delay differences and determining the first compensation data corresponding to the first epoch based on the complete carrier phase observations of the two receivers at the first epoch and the second compensation data corresponding to the first epoch includes:
[0019] Based on the complete carrier phase observations of the two receivers at the first epoch and the second compensation data corresponding to the first epoch, the first compensation data corresponding to the first epoch is determined by the following transmission delay difference calculation formula.
[0020]
[0021] The two receivers include receiver i and receiver j. This represents the zero-value error compensation value used by the two receivers for each satellite s, where τ is the time corresponding to the first epoch, c represents the speed of light, and Δt... 0,ij (τ) represents the difference between the time deviation of receiver i at the power-on moment and the time deviation of receiver j at the power-on moment. This represents the complete carrier phase observation between receiver i and satellite s. This represents the complete carrier phase observation between receiver j and satellite s.
[0022] Optionally, according to the power-on zero-value calibration method provided by the present invention, the step of determining the standard deviation of the power-on zero-value error compensation for each epoch based on the first compensation data corresponding to each epoch through a recursive method includes:
[0023] Based on the average value of the zero-value compensation and the variance of the zero-value compensation determined in the previous epoch of the second epoch, and the first compensation data corresponding to the second epoch, the average value of the zero-value compensation and the variance of the zero-value compensation corresponding to the second epoch are determined. The second epoch is any epoch other than the first epoch.
[0024] Based on the variance of the zero-value error compensation for startup corresponding to the second epoch, the standard deviation of the zero-value error compensation for startup corresponding to the second epoch is determined.
[0025] Optionally, according to the power-on zero-value calibration method provided by the present invention, the step of determining the power-on zero-value error compensation average value and power-on zero-value error compensation variance value corresponding to the second epoch based on the power-on zero-value error compensation average value and power-on zero-value error compensation variance value determined in the previous epoch of the second epoch and the first compensation data corresponding to the second epoch includes:
[0026] The average value of the startup zero-value error compensation corresponding to the second epoch is determined by the following average value recursion formula;
[0027]
[0028] Among them, A τ A represents the average value of the zero-value error compensation at the start-up corresponding to the second epoch, where τ is the time corresponding to the second epoch. τ-1 X represents the average value of the startup zero-value error compensation determined in the previous epoch of the second epoch. τ This represents the first compensation data corresponding to the second epoch.
[0029] Optionally, according to the power-on zero-value calibration method provided by the present invention, the step of determining the power-on zero-value error compensation average value and power-on zero-value error compensation variance value corresponding to the second epoch based on the power-on zero-value error compensation average value and power-on zero-value error compensation variance value determined in the previous epoch of the second epoch and the first compensation data corresponding to the second epoch includes:
[0030] The variance value for the startup zero-value error compensation corresponding to the second epoch is determined by the following variance value recursion formula;
[0031]
[0032] Among them, V τ This represents the variance of the zero-value error compensation at the start-up time corresponding to the second epoch, where τ is the time corresponding to the second epoch, and A τ-1 V represents the average value of the startup zero-value error compensation determined in the previous epoch of the second epoch. τ-1 X represents the variance of the startup zero-value error compensation determined in the previous epoch of the second epoch. τ This represents the first compensation data corresponding to the second epoch.
[0033] Secondly, the present invention also provides a power-on zero-value calibration device, comprising:
[0034] The first determining module is used to determine the first compensation data corresponding to each epoch based on the Doppler value, pseudorange observation value and complete carrier phase observation value of the two receivers at each epoch. The first compensation data is used to characterize the power-on zero value error compensation value adopted by the two receivers for each satellite.
[0035] The second determining module is used to determine the standard deviation of the startup zero value error compensation for each epoch based on the first compensation data corresponding to each epoch through a recursive method.
[0036] The third determination module is used to eliminate gross errors in the first compensation data corresponding to each epoch based on the standard deviation of the zero-value error compensation for each epoch, and to determine the second compensation data corresponding to each epoch by using the 3σ principle.
[0037] The fourth determining module is used to determine the power-on zero-value error compensation calibration value corresponding to each epoch by averaging the second compensation data corresponding to each epoch. The power-on zero-value error compensation calibration value is used to correct the power-on zero-value error between the two receivers.
[0038] The two receivers acquire satellite signals through the same antenna and are connected to the same external clock.
[0039] Thirdly, the present invention also 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 program to implement the power-on zero-value calibration method as described above.
[0040] Fourthly, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the power-on zero-value calibration method as described above.
[0041] The power-on zero-baseline calibration method, apparatus, electronic device, and storage medium provided by this invention, by configuring two receivers to acquire satellite signals using the same antenna and configuring the two receivers to be connected to the same external clock, can simulate a zero-baseline environment, minimizing atmospheric errors, antenna-end errors, and transmission path errors. Furthermore, by acquiring the Doppler values, pseudorange observations, and complete carrier phase observations of the two receivers at each epoch, the compensation value for the power-on zero-baseline calibration can be calculated using the Doppler values, pseudorange observations, and complete carrier phase observations. This allows for the determination of the first compensation data corresponding to each epoch, and further, based on the first compensation data corresponding to each epoch, the power-on zero-baseline calibration can be performed. The standard deviation of the zero-value error compensation for each epoch is determined by recursion. Then, the standard deviation of the zero-value error compensation for each epoch can be used to remove gross errors from the first compensation data for each epoch using the 3σ principle, and the second compensation data for each epoch (i.e., the compensation data after removing gross errors) can be determined. Then, based on the second compensation data for each epoch, the zero-value error compensation calibration value for each epoch can be determined by averaging. The zero-value error compensation calibration value can then be added to the carrier phase single difference part to correct the zero-value error between two receivers, enabling efficient calibration of the zero-value error for multiple receivers. Attached Figure Description
[0042] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0043] Figure 1 This is one of the flowcharts illustrating the power-on zero-value calibration method provided by the present invention;
[0044] Figure 2 This is a schematic diagram of the hardware structure for simulating a zero-baseline environment provided by the present invention;
[0045] Figure 3 This is the second flowchart of the power-on zero-value calibration method provided by the present invention;
[0046] Figure 4 This is the third flowchart of the power-on zero-value calibration method provided by the present invention;
[0047] Figure 5 This is the fourth flowchart of the power-on zero-value calibration method provided by the present invention;
[0048] Figure 6 This is a schematic diagram of the experimental results of multi-satellite tri-frequency startup zero-value error compensation between two receivers provided by the present invention;
[0049] Figure 7 This is a schematic diagram of the statistical results of the zero-value error compensation for startup provided by the present invention.
[0050] Figure 8 This is a schematic diagram of the power-on zero-value calibration device provided by the present invention;
[0051] Figure 9 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation
[0052] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.
[0053] Figure 1 This is one of the flowcharts illustrating the power-on zero-value calibration method provided by the present invention, such as... Figure 1 As shown, the execution subject of the power-on zero-value calibration method can be an electronic device, such as a computing core backplane. The method includes:
[0054] Step 101: Based on the Doppler values, pseudorange observations and complete carrier phase observations of the two receivers at each epoch, determine the first compensation data corresponding to each epoch. The first compensation data is used to characterize the power-on zero error compensation value adopted by the two receivers for each satellite.
[0055] The two receivers acquire satellite signals through the same antenna and are connected to the same external clock.
[0056] Specifically, Figure 2 This is a schematic diagram of the hardware structure of the simulated zero-baseline environment provided by the present invention, as shown below. Figure 2 As shown, in order to achieve zero-baseline calibration among multiple receivers, two receivers can be configured to use the same antenna to collect satellite signals, and two receivers (including receiver i and receiver j) can be configured to be connected to the same external clock. This can simulate a zero-baseline environment and eliminate atmospheric errors, antenna errors, and transmission path errors as much as possible.
[0057] By acquiring the Doppler values, pseudorange observations, and complete carrier phase observations of the two receivers at each epoch, the compensation values for the zero-value at startup can be calculated using the Doppler values, pseudorange observations, and complete carrier phase observations, thus determining the first compensation data corresponding to each epoch.
[0058] Step 102: Based on the first compensation data corresponding to each epoch, determine the standard deviation of the startup zero value error compensation corresponding to each epoch through a recursive method.
[0059] Specifically, for the first epoch, the startup zero-value error compensation value in the first compensation data can be statistically analyzed based on the first compensation data corresponding to the first epoch. The statistical results can include the mean, variance, and standard deviation. Based on the statistical results, the standard deviation of the startup zero-value error compensation corresponding to the first epoch can be obtained.
[0060] For any epoch after the first epoch, a recursive method can be used to determine the standard deviation of the zero-value error compensation corresponding to the epoch. For example, for a certain second epoch (the second epoch is any epoch other than the first epoch), statistical analysis can be performed based on the statistical results of the previous epoch and the first compensation data corresponding to the second epoch to obtain the statistical results corresponding to the second epoch (which may include the mean, variance, and standard deviation, etc.). Based on the statistical results corresponding to the second epoch, the standard deviation of the zero-value error compensation corresponding to the second epoch can be obtained.
[0061] Step 103: Based on the standard deviation of the zero-value error compensation for each epoch, the first compensation data for each epoch is removed by using the 3σ principle to determine the second compensation data for each epoch.
[0062] Specifically, for any epoch corresponding to the first compensation data, the standard deviation of the zero-value error compensation corresponding to that epoch can be used to remove outliers from the first compensation data of that epoch using the 3σ principle, thus determining the second compensation data of that epoch. After removing outliers from the first compensation data corresponding to each epoch, the second compensation data (i.e., the compensation data after removing outliers) corresponding to each epoch can be determined.
[0063] Step 104: Based on the second compensation data corresponding to each epoch, determine the power-on zero-value error compensation calibration value corresponding to each epoch by averaging. The power-on zero-value error compensation calibration value is used to correct the power-on zero-value error between the two receivers.
[0064] Specifically, for any given epoch, the second compensation data can be averaged to determine the power-on zero-value error compensation calibration value for that epoch. After averaging the second compensation data for each epoch, the power-on zero-value error compensation calibration value for each epoch can be determined. By adding the power-on zero-value error compensation calibration value to the carrier phase single-difference part, the power-on zero-value error between the two receivers can be corrected.
[0065] Understandably, time offset correction can be performed on general receiver boards using instantaneous Doppler values, pseudorange observations, and carrier phase observations. The hardware environment is easy to set up, requiring only the simulation of a zero-baseline scenario and multiple receivers connected to the same external clock. The algorithm has low complexity, a simple data processing flow, and low implementation cost.
[0066] The error caused by the zero value at startup is a major error in carrier phase observation. If it cannot be corrected, the error will be absorbed by the receiver clock error term, resulting in an additional error in the carrier phase observation. By adding the zero value at startup error compensation calibration value to the carrier phase single difference part, the zero value at startup error between the two receivers can be corrected, which can effectively reduce the observation error.
[0067] The power-on zero-value calibration method provided by this invention, by configuring two receivers to acquire satellite signals using the same antenna and by configuring the two receivers to be connected to the same external clock, can simulate a zero-baseline environment. Then, it can calculate the compensation value for the power-on zero value using Doppler values, pseudorange observations, and complete carrier phase observations, determining the first compensation data corresponding to each epoch. Based on the first compensation data corresponding to each epoch, it can then determine the standard deviation of the power-on zero-value error compensation for each epoch through a recursive method. Furthermore, it can use the standard deviation of the power-on zero-value error compensation to remove gross errors from the first compensation data corresponding to each epoch using the 3σ principle, determining the second compensation data corresponding to each epoch. Based on the second compensation data corresponding to each epoch, it can then determine the power-on zero-value error compensation calibration value corresponding to each epoch through averaging. Finally, the power-on zero-value error compensation calibration value can be added to the carrier phase single-difference part to correct the power-on zero-value error between the two receivers, enabling efficient calibration of the power-on zero value across multiple receivers.
[0068] Optionally, according to the power-on zero-value calibration method provided by the present invention, determining the first compensation data corresponding to each epoch based on the Doppler values, pseudorange observations, and complete carrier phase observations of the two receivers at each epoch includes:
[0069] Based on the Doppler values and pseudorange observations of the two receivers at the first epoch, the time difference is calculated using the pseudorange observations and compensation is performed using the Doppler values to determine the second compensation data corresponding to the first epoch. The first epoch can be any epoch.
[0070] Based on the complete carrier phase observations of the two receivers at the first epoch and the second compensation data corresponding to the first epoch, the transmission delay difference is eliminated, and the first compensation data corresponding to the first epoch is determined.
[0071] Specifically, Figure 3 This is the second flowchart illustrating the power-on zero-value calibration method provided by this invention, as shown below. Figure 3 As shown, the method includes steps 301 to 307.
[0072] Step 301: Determine the first epoch as the first epoch.
[0073] Step 302: Based on the Doppler values and pseudorange observations of the two receivers at the first epoch, the time difference is calculated using the pseudorange observations and compensation is performed using the Doppler values to determine the second compensation data corresponding to the first epoch.
[0074] Step 303: Based on the complete carrier phase observations of the two receivers at the first epoch and the second compensation data corresponding to the first epoch, eliminate the transmission delay difference and determine the first compensation data corresponding to the first epoch.
[0075] It is understandable that, considering the difference in transmission delay of the compensation carrier on different receiver boards, this difference will be absorbed by the clock bias. Under zero baseline conditions (in the case of zero baseline, the inter-station difference eliminates satellite-end error, ionospheric error, and tropospheric error), the difference in transmission delay can be eliminated based on the complete carrier phase observations of the two receivers at the first epoch and the second compensation data corresponding to the first epoch, so as to determine the first compensation data after eliminating the difference in transmission delay.
[0076] Step 304: Determine the standard deviation of the startup zero-value error compensation corresponding to the first epoch using a recursive method.
[0077] Step 305: Determine if the first epoch is the last epoch. If yes, proceed to step 306. Otherwise, determine the next epoch as the first epoch and proceed to step 302.
[0078] Step 306: Based on the standard deviation of the zero-value error compensation for each epoch, the first compensation data for each epoch is removed by using the 3σ principle to determine the second compensation data for each epoch.
[0079] Step 307: Based on the second compensation data corresponding to each epoch, determine the start-up zero value error compensation calibration value corresponding to each epoch by averaging.
[0080] Optionally, according to the power-on zero-value calibration method provided by the present invention, the step of determining the second compensation data corresponding to the first epoch based on the Doppler values and pseudorange observations of the two receivers at the first epoch, using the pseudorange observations to calculate the time difference and using the Doppler values for compensation, includes:
[0081] Based on the Doppler values and pseudorange observations of the two receivers at the first epoch, the second compensation data corresponding to the first epoch is determined by the following zero-value error compensation formula.
[0082]
[0083] The two receivers include receiver i and receiver j, where c represents the speed of light, and Δt 0,ij (τ) represents the difference between the time deviation of receiver i at the power-on time and the time deviation of receiver j at the power-on time, where τ is the time corresponding to the first epoch, λ represents the satellite signal wavelength, and f d,i (τ) represents the Doppler value of receiver i. This represents the pseudorange observation of receiver i with respect to satellite s at time τ. Let τ represent the pseudorange observation value of receiver j for satellite s at time τ.
[0084] Specifically, using the aforementioned zero-value error compensation formula, time difference can be calculated using pseudorange observations under zero-baseline conditions, and then compensated using instantaneous Doppler values to obtain the zero-value error compensation value. For each satellite, the zero-value error compensation value used by the two receivers can be determined based on the aforementioned zero-value error compensation formula to obtain the first compensation data corresponding to the epoch.
[0085] Optionally, according to the power-on zero-value calibration method provided by the present invention, the step of eliminating transmission delay differences and determining the first compensation data corresponding to the first epoch based on the complete carrier phase observations of the two receivers at the first epoch and the second compensation data corresponding to the first epoch includes:
[0086] Based on the complete carrier phase observations of the two receivers at the first epoch and the second compensation data corresponding to the first epoch, the first compensation data corresponding to the first epoch is determined by the following transmission delay difference calculation formula.
[0087]
[0088] The two receivers include receiver i and receiver j. This represents the zero-value error compensation value used by the two receivers for each satellite s, where τ is the time corresponding to the first epoch, c represents the speed of light, and Δt... 0,ij (τ) represents the difference between the time deviation of receiver i at the power-on moment and the time deviation of receiver j at the power-on moment. This represents the complete carrier phase observation between receiver i and satellite s. This represents the complete carrier phase observation between receiver j and satellite s.
[0089] Specifically, using the above formula for calculating transmission delay difference, the complete compensation value can be obtained using the carrier difference under zero baseline conditions. This complete compensation value can eliminate transmission delay differences to prevent them from being absorbed by clock bias.
[0090] Optionally, according to the power-on zero-value calibration method provided by the present invention, the step of determining the standard deviation of the power-on zero-value error compensation for each epoch based on the first compensation data corresponding to each epoch through a recursive method includes:
[0091] Based on the average value of the zero-value compensation and the variance of the zero-value compensation determined in the previous epoch of the second epoch, and the first compensation data corresponding to the second epoch, the average value of the zero-value compensation and the variance of the zero-value compensation corresponding to the second epoch are determined. The second epoch is any epoch other than the first epoch.
[0092] Based on the variance of the zero-value error compensation for startup corresponding to the second epoch, the standard deviation of the zero-value error compensation for startup corresponding to the second epoch is determined.
[0093] Specifically, Figure 4 This is the third flowchart of the power-on zero-value calibration method provided by the present invention, as shown below. Figure 4 As shown, the method includes steps 401 to 407.
[0094] Step 401: Based on the Doppler values, pseudorange observations, and complete carrier phase observations of the two receivers at the first epoch, determine the first compensation data corresponding to the first epoch.
[0095] Step 402: Based on the first compensation data corresponding to the first epoch, through statistical analysis, determine the average value of the startup zero-value error compensation, the variance of the startup zero-value error compensation, and the standard deviation of the startup zero-value error compensation corresponding to the first epoch.
[0096] Step 403: Based on the average value of the zero-value compensation for startup and the variance of the zero-value compensation for startup determined in the previous epoch of the second epoch, and the first compensation data corresponding to the second epoch, determine the average value of the zero-value compensation for startup and the variance of the zero-value compensation for startup corresponding to the second epoch.
[0097] Step 404: Based on the variance of the zero-value error compensation for startup corresponding to the second epoch, determine the standard deviation of the zero-value error compensation for startup corresponding to the second epoch.
[0098] Step 405: Determine if the second epoch is the last epoch. If yes, proceed to step 406. Otherwise, determine the next epoch as the second epoch and proceed to step 403.
[0099] Step 406: Based on the standard deviation of the zero-value error compensation corresponding to each epoch, the first compensation data corresponding to each epoch is subjected to gross error elimination by the 3σ principle to determine the second compensation data corresponding to each epoch.
[0100] Step 407: Based on the second compensation data corresponding to each epoch, determine the start-up zero value error compensation calibration value corresponding to each epoch by averaging.
[0101] Understandably, the complete compensation value The compensation value is only related to the receiver and not to the satellite; the compensation values calculated by different satellites should be roughly the same. The startup zero value is related to the receiver's startup operation, so it should be calculated every time the receiver is powered on. The startup zero value cannot be calculated retrospectively; therefore, its average and variance calculations should be performed using real-time stored values or a recursive method. The recursive method can determine the standard deviation of the startup zero value error compensation for each epoch. Using the 3σ principle, gross errors are eliminated from the first compensation data for each epoch, determining the second compensation data (i.e., the compensation data after eliminating gross errors). Then, based on the second compensation data for each epoch, the startup zero value error compensation calibration value for each epoch can be determined by averaging. This startup zero value error compensation calibration value can then be added to the carrier phase single-difference part to correct the startup zero value error between the two receivers.
[0102] Optionally, according to the power-on zero-value calibration method provided by the present invention, the step of determining the power-on zero-value error compensation average value and power-on zero-value error compensation variance value corresponding to the second epoch based on the power-on zero-value error compensation average value and power-on zero-value error compensation variance value determined in the previous epoch of the second epoch and the first compensation data corresponding to the second epoch includes:
[0103] The average value of the startup zero-value error compensation corresponding to the second epoch is determined by the following average value recursion formula;
[0104]
[0105] Among them, A τ A represents the average value of the zero-value error compensation at the start-up corresponding to the second epoch, where τ is the time corresponding to the second epoch. τ-1 X represents the average value of the startup zero-value error compensation determined in the previous epoch of the second epoch. τ This represents the first compensation data corresponding to the second epoch.
[0106] Specifically, using the above average recursive formula, the average value of the zero-value error compensation for startup determined in the previous epoch of the second epoch and the variance of the zero-value error compensation for startup determined in the previous epoch of the second epoch can be used to perform mean statistical analysis to determine the average value of the zero-value error compensation for startup corresponding to the second epoch.
[0107] Optionally, according to the power-on zero-value calibration method provided by the present invention, the step of determining the power-on zero-value error compensation average value and power-on zero-value error compensation variance value corresponding to the second epoch based on the power-on zero-value error compensation average value and power-on zero-value error compensation variance value determined in the previous epoch of the second epoch and the first compensation data corresponding to the second epoch includes:
[0108] The variance value for the startup zero-value error compensation corresponding to the second epoch is determined by the following variance value recursion formula;
[0109]
[0110] Among them, V τ This represents the variance of the zero-value error compensation at the start-up time corresponding to the second epoch, where τ is the time corresponding to the second epoch, and A τ-1 V represents the average value of the startup zero-value error compensation determined in the previous epoch of the second epoch. τ-1 X represents the variance of the startup zero-value error compensation determined in the previous epoch of the second epoch. τ This represents the first compensation data corresponding to the second epoch.
[0111] Specifically, using the above variance recursive formula, variance statistical analysis can be performed based on the average value of the zero-value error compensation determined in the previous epoch of the second epoch, the variance value of the zero-value error compensation, and the first compensation data corresponding to the second epoch, to determine the zero-value error compensation variance value corresponding to the second epoch.
[0112] Optionally, Figure 5 This is the fourth flowchart of the power-on zero-value calibration method provided by the present invention, as shown below. Figure 5 As shown, the method includes steps 501 to 504.
[0113] The receiver board has a time deviation in signal sampling. The impact of this time deviation will be reflected in the local clock bias of receiver i, as shown in the following local clock bias formula:
[0114] dt′ i =t 0，i +Δf i T s N;
[0115] Among them, dt′ i t represents the local clock bias of receiver i. 0，i The time deviation at the moment receiver i is powered on, also known as the power-on zero value, Δf i T represents the clock frequency of receiver i. s represents the sampling interval, and N represents the number of samples.
[0116] By subtracting the local clock error of receiver i from the local clock error of receiver j, we can obtain the following formula:
[0117] Δdt′ ij =t 0，i -t 0，j +(Δf i -Δf j )T s N;
[0118] Among them, t 0，j Δf represents the time deviation at the moment receiver j is powered on. j This represents the clock frequency of receiver j.
[0119] If the two receivers operate at the same frequency source, then in the above difference formula, Δf i -Δf j =0, at this time if t 0，i and t 0，j If they are equal, the effect of receiver clock bias can be eliminated when calculating differences between stations. Let Δt be the value of Δt. 0，ij =t 0，i -t 0，j , Δt 0，ij Elimination at the hardware level requires two receivers to be completely synchronized in time, which is difficult to achieve. Compensation can be performed at the algorithm level through the following steps 501 to 504.
[0120] Step 501, Hardware environment setup.
[0121] Specifically, such as Figure 2 As shown, the same antenna can be used to collect the same signal and distribute it to two receivers, i and j, to simulate a zero-baseline environment and minimize atmospheric errors, antenna errors, and transmission path errors. Receivers i and j are connected to the same external clock to achieve a common-source frequency effect.
[0122] Step 502, raw data acquisition.
[0123] Specifically, since the calculation results of a single epoch may have low accuracy due to the influence of observation errors, the method of averaging over multiple epochs and eliminating gross errors is generally adopted. Assuming that the total number of observation epochs is n, the raw data acquisition includes acquiring and storing the Doppler values, pseudorange observations, and complete carrier phase observations of n epochs from two receivers.
[0124] Step 503, calculate the zero value upon startup.
[0125] Specifically, under zero-baseline conditions, the two receivers use pseudorange and Doppler values to correlate Δt. 0,ij Compensation is performed. At time τ, Δt 0,ijThe zero-value error compensation at startup can be expressed by the following formula:
[0126]
[0127] Here, the two receivers are receiver i and receiver j, c represents the speed of light, and Δt 0,ij (τ) represents the difference between the time deviation of receiver i at the power-on time and the time deviation of receiver j at the power-on time, where τ is the time corresponding to the first epoch, λ represents the satellite signal wavelength, and f d,i (τ) represents the Doppler value of receiver i. This represents the pseudorange observation of receiver i with respect to satellite s at time τ. Let τ represent the pseudorange observation value of receiver j for satellite s at time τ.
[0128] It is understandable that, using the above-mentioned zero-value error compensation formula, the time difference can be calculated using pseudorange observations, and then compensated using instantaneous Doppler values.
[0129] Furthermore, considering the difference in transmission delay of the compensation carrier on different receiver boards, this difference is absorbed by the clock bias. Therefore, under zero baseline conditions, the complete compensation value can be obtained using the carrier difference. The difference in transmission delay can be expressed using the following formula:
[0130]
[0131] The two receivers are receiver i and receiver j. This represents the zero-value error compensation value used by the two receivers for each satellite s, where τ is the time corresponding to the first epoch, c represents the speed of light, and Δt is the zero-value error compensation value. 0,ij (τ) represents the difference between the time deviation of receiver i at the power-on moment and the time deviation of receiver j at the power-on moment. This represents the complete carrier phase observation between receiver i and satellite s. This value should include the ambiguity component. This represents the complete carrier phase observation between receiver j and satellite s, and this value should include the ambiguity portion.
[0132] Since, under zero baseline conditions, inter-station differences eliminate satellite-end errors, ionospheric errors, and tropospheric errors, they are disregarded. The compensation value for the zero-value at time τ can be obtained using the aforementioned formula for calculating transmission delay differences.
[0133] Step 504: Data statistical analysis and processing.
[0134] Specifically, based on the above formula for calculating transmission delay difference, the zero-value compensation for each epoch can be obtained. The set of compensation values for multiple stars over n epochs (i.e., the first compensation data corresponding to each epoch) can be represented as follows:
[0135]
[0136] It is only related to the receiver and not to the satellite; the correction values calculated by different satellites should be roughly the same. As can be seen from the local clock bias formula above, the startup zero value is related to the receiver's startup operation. Therefore, it should be calculated every time the receiver is powered on. The startup zero value cannot be calculated retrospectively; its average and variance should be calculated using real-time stored values or a recursive method. The recursive formula is as follows.
[0137] The recursive formula for the average value is as follows:
[0138]
[0139] Among them, A τ A represents the average value of the zero-value error compensation at the start-up corresponding to the second epoch, where τ is the time corresponding to the second epoch. τ-1 X represents the average value of the startup zero-value error compensation determined in the previous epoch of the second epoch. τ This represents the first compensation data corresponding to the second epoch.
[0140] The recursive formula for variance is as follows:
[0141]
[0142] Among them, V τ This represents the variance of the zero-value error compensation at the start-up time corresponding to the second epoch, where τ is the time corresponding to the second epoch, and A τ-1 V represents the average value of the startup zero-value error compensation determined in the previous epoch of the second epoch. τ-1 X represents the variance of the startup zero-value error compensation determined in the previous epoch of the second epoch. τ This represents the first compensation data corresponding to the second epoch.
[0143] The formula for standard deviation is as follows:
[0144]
[0145] Among them, V τ and σ τ Let be the variance and standard deviation at time τ.
[0146] Using the 3σ principle to remove outliers, a new dataset free of outliers is obtained (i.e., the second compensation data corresponding to each epoch). Then, the calculation is repeated. The average value is used as the final zero-value compensation value for startup (i.e., the zero-value error compensation calibration value for startup). The final zero-value compensation value for startup should be added to the carrier phase single difference part for correction.
[0147] Figure 6 This is a schematic diagram illustrating the experimental results of multi-satellite tri-frequency startup zero-value error compensation between two receivers provided by the present invention. Figure 7 This is a schematic diagram of the statistical results of the power-on zero-value error compensation provided by the present invention. The influence of ambiguity was ignored during the calculation process; only the decimal part of the power-on zero-value correction was calculated. Figure 6 The results show the calculated zero-values for multiple satellites at three frequency points: GL1, B1I, and B1C. It can be seen that the correction values (compensation values) are the same for different satellites at the same frequency. The zero-value correction is related to the receiver but not to the satellite, which is consistent with reality. Figure 7 The paper presents the time-series statistics of the zero-values of all satellites at multiple stations (including stations A, B, C, and D). GL1 and B1C have the same frequency, but not the same as B1I. Therefore, the zero-values at the frequencies of GL1 and B1C are close but different from those of B1C. This is consistent with the derivation of the zero-value error compensation formula mentioned above. The zero-value compensation value is related to the instantaneous Doppler, which is related to the signal frequency.
[0148] The power-on zero-value calibration method provided by this invention, by configuring two receivers to acquire satellite signals using the same antenna and by configuring the two receivers to be connected to the same external clock, can simulate a zero-baseline environment. Then, it can calculate the compensation value for the power-on zero value using Doppler values, pseudorange observations, and complete carrier phase observations, determining the first compensation data corresponding to each epoch. Based on the first compensation data corresponding to each epoch, it can then determine the standard deviation of the power-on zero-value error compensation for each epoch through a recursive method. Furthermore, it can use the standard deviation of the power-on zero-value error compensation to remove gross errors from the first compensation data corresponding to each epoch using the 3σ principle, determining the second compensation data corresponding to each epoch. Based on the second compensation data corresponding to each epoch, it can then determine the power-on zero-value error compensation calibration value corresponding to each epoch through averaging. Finally, the power-on zero-value error compensation calibration value can be added to the carrier phase single-difference part to correct the power-on zero-value error between the two receivers, enabling efficient calibration of the power-on zero value across multiple receivers.
[0149] The power-on zero-value calibration device provided by the present invention is described below. The power-on zero-value calibration device described below and the power-on zero-value calibration method described above can be referred to in correspondence.
[0150] Figure 8 This is a schematic diagram of the power-on zero-value calibration device provided by the present invention, as shown below. Figure 8As shown, the device includes: a first determining module 801, a second determining module 802, a third determining module 803, and a fourth determining module 804, wherein:
[0151] The first determining module 801 is used to determine the first compensation data corresponding to each epoch based on the Doppler value, pseudorange observation value and complete carrier phase observation value of the two receivers at each epoch. The first compensation data is used to characterize the power-on zero value error compensation value adopted by the two receivers for each satellite.
[0152] The second determining module 802 is used to determine the standard deviation of the startup zero value error compensation for each epoch based on the first compensation data corresponding to each epoch through a recursive method.
[0153] The third determination module 803 is used to determine the second compensation data corresponding to each epoch by removing gross errors from the first compensation data corresponding to each epoch based on the standard deviation of the zero-value error compensation for each epoch corresponding to each epoch through the 3σ principle.
[0154] The fourth determining module 804 is used to determine the power-on zero error compensation calibration value corresponding to each epoch by averaging the second compensation data corresponding to each epoch. The power-on zero error compensation calibration value is used to correct the power-on zero error between the two receivers.
[0155] The two receivers acquire satellite signals through the same antenna and are connected to the same external clock.
[0156] Figure 9 This is a schematic diagram of the structure of the electronic device provided by the present invention, such as... Figure 9 As shown, the electronic device may include: a processor 910, a communication interface 920, a memory 930, and a communication bus 940, wherein the processor 910, the communication interface 920, and the memory 930 communicate with each other through the communication bus 940. The processor 910 can call logical instructions in the memory 930 to execute a power-on zero-value calibration method, which includes:
[0157] Based on the Doppler values, pseudorange observations, and complete carrier phase observations of the two receivers at each epoch, the first compensation data corresponding to each epoch is determined. The first compensation data is used to characterize the power-on zero error compensation value adopted by the two receivers for each satellite.
[0158] Based on the first compensation data corresponding to each epoch, the standard deviation of the start-up zero value error compensation corresponding to each epoch is determined by recursion.
[0159] Based on the standard deviation of the zero-value error compensation corresponding to each epoch, the first compensation data corresponding to each epoch is removed by the 3σ principle to determine the second compensation data corresponding to each epoch.
[0160] Based on the second compensation data corresponding to each epoch, the power-on zero value error compensation calibration value corresponding to each epoch is determined by averaging. The power-on zero value error compensation calibration value is used to correct the power-on zero value error between the two receivers.
[0161] The two receivers acquire satellite signals through the same antenna and are connected to the same external clock.
[0162] Furthermore, the logical instructions in the aforementioned memory 930 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.
[0163] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the power-on zero-value calibration method provided by the methods described above, the method comprising:
[0164] Based on the Doppler values, pseudorange observations, and complete carrier phase observations of the two receivers at each epoch, the first compensation data corresponding to each epoch is determined. The first compensation data is used to characterize the power-on zero error compensation value adopted by the two receivers for each satellite.
[0165] Based on the first compensation data corresponding to each epoch, the standard deviation of the start-up zero value error compensation corresponding to each epoch is determined by recursion.
[0166] Based on the standard deviation of the zero-value error compensation corresponding to each epoch, the first compensation data corresponding to each epoch is removed by the 3σ principle to determine the second compensation data corresponding to each epoch.
[0167] Based on the second compensation data corresponding to each epoch, the power-on zero value error compensation calibration value corresponding to each epoch is determined by averaging. The power-on zero value error compensation calibration value is used to correct the power-on zero value error between the two receivers.
[0168] The two receivers acquire satellite signals through the same antenna and are connected to the same external clock.
[0169] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.
[0170] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.
[0171] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for zero-value calibration upon power-on, characterized in that, include: Based on the Doppler values, pseudorange observations, and complete carrier phase observations of the two receivers at each epoch, the first compensation data corresponding to each epoch is determined. The first compensation data is used to characterize the power-on zero error compensation value adopted by the two receivers for each satellite. Based on the first compensation data corresponding to each epoch, the standard deviation of the start-up zero value error compensation corresponding to each epoch is determined by recursion. Based on the standard deviation of the zero-value error compensation corresponding to each epoch, the first compensation data corresponding to each epoch is removed by the 3σ principle to determine the second compensation data corresponding to each epoch. Based on the second compensation data corresponding to each epoch, the power-on zero value error compensation calibration value corresponding to each epoch is determined by averaging. The power-on zero value error compensation calibration value is used to correct the power-on zero value error between the two receivers. The two receivers acquire satellite signals through the same antenna and are connected to the same external clock. The first compensation data corresponding to the first epoch is determined by the following transmission delay difference calculation formula. ； The two receivers include receivers and receiver , This indicates the status of each satellite. The power-on zero-value error compensation values used by the two receivers, This refers to the time corresponding to the first epoch. Represents the speed of light. Indicates receiver Time deviation at power-on time and receiver The difference between the time deviations at the moment of power-on. Indicates receiver With satellite Complete carrier phase observations between Indicates receiver With satellite Complete carrier phase observations between; The first epoch can be any epoch; The step of determining the standard deviation of the startup zero-value error compensation for each epoch based on the first compensation data corresponding to each epoch through a recursive method includes: Based on the average value of the zero-value compensation and the variance of the zero-value compensation determined in the previous epoch of the second epoch, and the first compensation data corresponding to the second epoch, the average value of the zero-value compensation and the variance of the zero-value compensation corresponding to the second epoch are determined. The second epoch is any epoch other than the first epoch. Based on the variance value of the zero-value error compensation for startup corresponding to the second epoch, determine the standard deviation of the zero-value error compensation for startup corresponding to the second epoch. The average value of the startup zero-value error compensation corresponding to the second epoch is determined by the following average value recursion formula; ； in, This represents the average value of the startup zero-value error compensation corresponding to the second epoch. This refers to the time corresponding to the second epoch. This represents the average value of the startup zero-value error compensation determined in the previous epoch of the second epoch. This represents the first compensation data corresponding to the second epoch.
2. The power-on zero-value calibration method according to claim 1, characterized in that, The determination of the first compensation data corresponding to each epoch, based on the Doppler values, pseudorange observations, and complete carrier phase observations of the two receivers at each epoch, includes: Based on the Doppler values and pseudorange observations of the two receivers at the first epoch, the time difference is calculated using the pseudorange observations and compensation is performed using the Doppler values to determine the second compensation data corresponding to the first epoch. The first epoch can be any epoch. Based on the complete carrier phase observations of the two receivers at the first epoch and the second compensation data corresponding to the first epoch, the transmission delay difference is eliminated, and the first compensation data corresponding to the first epoch is determined.
3. The power-on zero-value calibration method according to claim 2, characterized in that, The process involves calculating the time difference using the pseudorange observations from the two receivers at the first epoch, and compensating using the Doppler values to determine the second compensation data corresponding to the first epoch. This includes: Based on the Doppler values and pseudorange observations of the two receivers at the first epoch, the second compensation data corresponding to the first epoch is determined by the following zero-value error compensation formula. ； The two receivers include receivers and receiver , Represents the speed of light. Indicates receiver Time deviation at power-on time and receiver The difference between the time deviations at the moment of power-on. This refers to the time corresponding to the first epoch. Indicates the wavelength of the satellite signal. Indicates receiver Doppler value, express Time Receiver For satellites pseudorange observations, express Time Receiver For satellites The pseudorange observations.
4. The power-on zero-value calibration method according to claim 1, characterized in that, The determination of the average value and variance of the zero-value compensation for startup based on the previous epoch of the second epoch, and the first compensation data corresponding to the second epoch, includes: The variance value for the startup zero-value error compensation corresponding to the second epoch is determined by the following variance value recursion formula; ； in, This represents the variance value of the zero-value error compensation corresponding to the second epoch. This refers to the time corresponding to the second epoch. This represents the average value of the startup zero-value error compensation determined in the previous epoch of the second epoch. This represents the variance of the startup zero-value error compensation determined in the previous epoch of the second epoch. This represents the first compensation data corresponding to the second epoch.
5. A power-on zero-value calibration device, characterized in that, include: The first determining module is used to determine the first compensation data corresponding to each epoch based on the Doppler value, pseudorange observation value and complete carrier phase observation value of the two receivers at each epoch. The first compensation data is used to characterize the power-on zero value error compensation value adopted by the two receivers for each satellite. The second determining module is used to determine the standard deviation of the startup zero value error compensation for each epoch based on the first compensation data corresponding to each epoch through a recursive method. The third determination module is used to eliminate gross errors in the first compensation data corresponding to each epoch based on the standard deviation of the zero-value error compensation for each epoch, and to determine the second compensation data corresponding to each epoch by using the 3σ principle. The fourth determining module is used to determine the power-on zero-value error compensation calibration value corresponding to each epoch by averaging the second compensation data corresponding to each epoch. The power-on zero-value error compensation calibration value is used to correct the power-on zero-value error between the two receivers. The two receivers acquire satellite signals through the same antenna and are connected to the same external clock. The first compensation data corresponding to the first epoch is determined by the following transmission delay difference calculation formula. ； The two receivers include receivers and receiver , This indicates the status of each satellite. The power-on zero-value error compensation values used by the two receivers, This refers to the time corresponding to the first epoch. Represents the speed of light. Indicates receiver Time deviation at power-on time and receiver The difference between the time deviations at the moment of power-on. Indicates receiver With satellite Complete carrier phase observations between Indicates receiver With satellite Complete carrier phase observations between; The first epoch can be any epoch; The step of determining the standard deviation of the startup zero-value error compensation for each epoch based on the first compensation data corresponding to each epoch through a recursive method includes: Based on the average value of the zero-value compensation and the variance of the zero-value compensation determined in the previous epoch of the second epoch, and the first compensation data corresponding to the second epoch, the average value of the zero-value compensation and the variance of the zero-value compensation corresponding to the second epoch are determined. The second epoch is any epoch other than the first epoch. Based on the variance value of the zero-value error compensation for startup corresponding to the second epoch, determine the standard deviation of the zero-value error compensation for startup corresponding to the second epoch. The average value of the startup zero-value error compensation corresponding to the second epoch is determined by the following average value recursion formula; ； in, This represents the average value of the startup zero-value error compensation corresponding to the second epoch. This refers to the time corresponding to the second epoch. This represents the average value of the startup zero-value error compensation determined in the previous epoch of the second epoch. This represents the first compensation data corresponding to the second epoch.
6. 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 power-on zero-value calibration method as described in any one of claims 1 to 4.
7. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the power-on zero value calibration method as described in any one of claims 1 to 4.