CN120595333B - Time service method, device, equipment and medium based on low-rail-pass-channel fusion signal - Google Patents
Time service method, device, equipment and medium based on low-rail-pass-channel fusion signalInfo
- Publication number
- CN120595333B CN120595333B CN202511107853.XA CN202511107853A CN120595333B CN 120595333 B CN120595333 B CN 120595333B CN 202511107853 A CN202511107853 A CN 202511107853A CN 120595333 B CN120595333 B CN 120595333B
- Authority
- CN
- China
- Prior art keywords
- epoch
- receiver
- clock difference
- weighted
- observation data
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Position Fixing By Use Of Radio Waves (AREA)
Abstract
The application relates to a time service method, a time service device and a time service medium based on a low-rail-pass-channel fusion signal. The method comprises the steps of receiving multi-epoch observation data for Doppler positioning, constructing a multi-epoch clock difference correlation model based on a multi-epoch Zhong Piao invariable hypothesis, combining receiver position coordinates, constructing a multi-epoch pseudo-range observation equation set, weighting according to comprehensive error estimation of different epochs, constructing a multi-epoch weighted clock difference solution model for weighted least square solution, screening the multi-epoch observation data, re-carrying out multi-epoch weighted least square clock difference solution according to the screened multi-epoch observation data and the multi-epoch weighted clock difference solution model, obtaining an optimized multi-epoch period starting time receiver clock difference and an optimized multi-epoch period receiver Zhong Piao, calculating the optimized current epoch receiver clock difference, correcting the receiver local time, and completing time service. The method can remarkably improve time service precision and stability.
Description
Technical Field
The application relates to the technical field of satellite navigation high-precision time service, in particular to a time service method, device, equipment and medium based on a low-orbit-guided fusion signal.
Background
The current construction of multiple low-orbit satellite constellations has entered a stage of scale deployment. The low orbit satellite constellation shows unique value in a modern space information system by virtue of obvious cost advantage and global coverage capability, on one hand, the low orbit system has strong survivability, low transmission delay and low power consumption link, on the other hand, the low orbit height ensures that the satellite has short operation period and high updating speed, and the number of visible satellites can be obviously increased and the space geometry configuration can be optimized if large-scale constellation deployment is matched. In the field of low-orbit navigation enhancement, the architecture of the communication fusion technology constructs the independent positioning capability of a low-orbit system by multiplexing the special ranging signals broadcast by communication resources, a receiver can perform Doppler positioning by receiving the navigation messages and related information broadcast by communication time slot signals, and on the basis of positioning, a user autonomously calculates the clock difference of the receiver to correct the local time, so that the local time is synchronous with the satellite system time, and time service is realized. The accuracy of the receiver clock error resolution directly affects the accuracy level of the time service.
The existing positioning time service method based on the low-orbit-transfer-ratio fusion signal is generally applied to a static scene of a receiver, the clock error of the receiver can be obtained only by one satellite in the current epoch, but the method is influenced by low pseudo-range measurement precision of the low-orbit-transfer-ratio fusion signal, large atmospheric delay correction error and the like, so that the fluctuation range of the precision of the code pseudo-range is large, the time service result is easy to generate large jump, and even satellite data used under certain conditions are abnormal, so that the time service precision is not satisfied. Therefore, the method has higher degree of dependence on satellite data quality at the current moment, has poor stability and is difficult to ensure time service precision.
Disclosure of Invention
In view of the foregoing, it is necessary to provide a time service method, device, equipment and medium based on a low-rail-pass fusion signal, which can significantly improve time service accuracy and stability.
A time service method based on a low-rail-pass fusion signal, the method comprising:
receiving multi-epoch observation data of the low-rail lead fusion signal by using a receiver, and acquiring the position coordinates of the receiver through Doppler positioning;
constructing a multi-epoch clock difference correlation model based on the multi-epoch Zhong Piao constant hypothesis;
Constructing a multi-epoch pseudo-range observation equation set by combining the multi-epoch clock difference correlation model and the receiver position coordinates, weighting a least square solution form of the multi-epoch pseudo-range observation equation set according to the comprehensive error estimation of different epochs in the clock difference solution process, constructing a multi-epoch weighted clock difference solution model and carrying out weighted least square solution;
Performing clock difference calculation according to the single epoch observation data, and performing multi epoch observation data screening by comparing the difference between the receiver clock difference obtained by the single epoch observation data calculation and the receiver clock difference obtained by the weighted least square calculation;
And re-performing multi-epoch weighted least square clock difference calculation according to the screened multi-epoch observation data and the multi-epoch weighted clock difference calculation model to obtain an optimized multi-epoch period starting time receiver clock difference and a receiver Zhong Piao in the multi-epoch period, calculating the optimized current epoch receiver clock difference, correcting the local time of the receiver, and completing time service.
In one embodiment, receiving multi-epoch observations of a low-rail-guided fusion signal with a receiver and obtaining receiver position coordinates via doppler positioning includes:
Receiving multi-epoch observation data within a certain time span range of the low-orbit guided fusion signal by using a receiver, wherein the multi-epoch observation data comprises a plurality of groups of satellite positions, satellite speeds, doppler frequency observables, pseudo-range observables and error correction parameters;
after receiving at least 4 groups of observation data, acquiring a receiver position initial value and a receiver Zhong Piao initial value by adopting an initial value search algorithm, establishing a Doppler positioning equation set in parallel, and acquiring a receiver three-dimensional position coordinate and a receiver Zhong Piao by solving through a Newton iteration method.
In one embodiment, an initial value search algorithm is used to obtain an initial value of a receiver position and an initial value of a receiver Zhong Piao, a doppler positioning equation set is constructed in parallel, and a three-dimensional position coordinate of the receiver and the receiver Zhong Piao are obtained through solving by a newton iteration method, which includes:
The method comprises the steps of adopting a grid-based initial value searching algorithm, carrying out equidistant grid division on a satellite receiving signals, carrying out least square calculation on the ground surface area covered by the signals, and searching one by one to obtain a receiver position initial value and a receiver Zhong Piao initial value;
Constructing a receiver static instantaneous Doppler observation equation expressed as:
;
Wherein, the In order to be a doppler frequency,For three-dimensional position coordinates by the receiverAnd a receiver Zhong PiaoThe four dimensions of the structure are subject to unknowns,For the doppler frequency measurement error,For the frequency of the transmitted signal of the satellite,In order to be the speed of motion of the satellite,In the form of satellite position coordinates,Is the speed of light;
Taking four-dimensional unknown data into consideration, constructing a Doppler positioning equation set simultaneously after receiving at least 4 sets of observation data, and obtaining three-dimensional position coordinates of a receiver through solving by Newton iteration method And a receiver Zhong Piao。
In one embodiment, constructing a multi-epoch clock-difference correlation model based on the multi-epoch Zhong Piao invariant assumption, includes:
Assume that receiver Zhong Piao is selected for a short period of time consisting of one epoch UnchangedFor unknowns, a multi-epoch clock difference correlation model is constructed, expressed as:
;
Wherein, the Receiver clock skew for the ith epoch,For the receiver clock difference initial value at the start of the selected multi-epoch period,For the time when the receiver receives the i-th epoch observation,For the time when the receiver receives the selected observation data at the start of the multi-epoch period,,The first epoch is also referred to as the current epoch.
In one embodiment, a multi-epoch pseudo-range observation equation set is constructed by combining a multi-epoch clock difference correlation model and receiver position coordinates, wherein the pseudo-range observation equation of a single epoch in the multi-epoch pseudo-range observation equation set is expressed as:
;
Wherein, the The pseudorange values measured for the ith epoch receiver and corrected for satellite clock differences, ionospheric delays and tropospheric delays,The three-dimensional position coordinates of the receiver obtained for the doppler positioning solution,For the satellite position coordinates of the ith epoch,The pseudorange measurement error for the ith epoch.
In one embodiment, weighting a least square solution form of the multi-epoch pseudo-range observation equation set according to the comprehensive error estimation of different epochs in the clock difference solution process, constructing a multi-epoch weighted clock difference solution model, and performing weighted least square solution, including:
Pseudo-range measurement error and atmospheric propagation error in the process of calculating the clock difference of the ith epoch are estimated, and the comprehensive error of the ith epoch is synthesized based on a square method and a root method Expressed as:
;
Wherein, the Representing the standard deviation of the pseudorange measurement error for a satellite at the ith epoch,For pseudorange measurements of receiver related parameters,Carrier-to-noise ratio of the received signal for the ith epoch; the standard deviation of the atmospheric propagation error for a satellite at the ith epoch, The satellite elevation angle of the ith epoch, and a and b are set empirical values;
constructing a weight matrix according to the comprehensive error of each epoch Expressed as:
;
Wherein, the The representation extracts the diagonal elements and,A weight representing the participation of a satellite in the weighted least squares solution of the ith epoch;
Converting the multi-epoch pseudo-range observation equation set into a least square solution form and substituting the least square solution form into a weight matrix Constructing and obtaining a multi-epoch weighted clock difference solution model, which is expressed as:
;
Wherein, the Is a coefficient matrix, wherein the first column is the receiver clock difference at the selected starting time of the multi-epoch periodThe second column is the receiver Zhong PiaoCoefficients of (1), superscriptThe transpose of the matrix is represented,For the time when the receiver receives the i-th epoch observation,;Is an observation residual vector;
the weighted least square solution is carried out on the multi-epoch weighted clock difference solution model, and the calculation is carried out AndAnd willAndSubstituting into a multi-epoch clock difference correlation model, and calculating to obtain the receiver clock difference obtained by each epoch weighted least square solutionWherein, the method comprises the steps of,,For the total number of epochs selected.
In one embodiment, the clock difference calculating is performed according to the single epoch observation data, and the multi epoch observation data screening is performed by comparing the difference between the receiver clock difference obtained by the single epoch observation data calculating and the receiver clock difference obtained by the weighted least squares calculating, including:
Performing clock difference calculation according to single epoch observation data, wherein the clock difference calculation is expressed as follows:
;
Wherein, the Representing the receiver clock difference obtained by solving the single epoch observation data for the i-th epoch,The pseudorange values measured for the ith epoch receiver and corrected for satellite clock differences, ionospheric delays and tropospheric delays,The three-dimensional position coordinates of the receiver obtained for the doppler positioning solution,Satellite position coordinates for the ith epoch;
Comparing one by one Receiver clock error obtained by solving weighted least squareThe absolute value of the difference between the two values and the set threshold T, ifAnd eliminating the observation data of the ith epoch to obtain a group of screened multi-epoch observation data.
A time service device based on a low-rail-pass fusion signal, the device comprising:
the data receiving and positioning module is used for receiving multi-epoch observation data of the low-rail communication fusion signal by using the receiver and acquiring the position coordinates of the receiver through Doppler positioning;
The clock difference correlation modeling module is used for constructing a multi-epoch clock difference correlation model based on the assumption that the multi-epoch Zhong Piao is unchanged;
The multi-epoch weighted clock difference resolving module is used for constructing a multi-epoch pseudo-range observation equation set by combining the multi-epoch clock difference correlation model and the receiver position coordinates, weighting the least square resolving form of the multi-epoch pseudo-range observation equation set according to the comprehensive error estimation of different epochs in the clock difference resolving process, constructing a multi-epoch weighted clock difference resolving model and carrying out weighted least square resolving;
The data screening module is used for carrying out clock difference calculation according to the single epoch observation data, and carrying out multi epoch observation data screening by comparing the difference between the receiver clock difference obtained by the single epoch observation data calculation and the receiver clock difference obtained by the weighted least square calculation;
the clock difference optimization and local time correction module is used for re-carrying out multi-epoch weighted least square clock difference calculation according to the screened multi-epoch observation data and the multi-epoch weighted clock difference calculation model to obtain an optimized multi-epoch period starting time receiver clock difference and an optimized multi-epoch period receiver Zhong Piao, calculating the optimized current epoch receiver clock difference, correcting the local time of the receiver, and completing time service.
A computer device comprising a memory storing a computer program and a processor which when executing the computer program performs the steps of:
receiving multi-epoch observation data of the low-rail lead fusion signal by using a receiver, and acquiring the position coordinates of the receiver through Doppler positioning;
constructing a multi-epoch clock difference correlation model based on the multi-epoch Zhong Piao constant hypothesis;
Constructing a multi-epoch pseudo-range observation equation set by combining the multi-epoch clock difference correlation model and the receiver position coordinates, weighting a least square solution form of the multi-epoch pseudo-range observation equation set according to the comprehensive error estimation of different epochs in the clock difference solution process, constructing a multi-epoch weighted clock difference solution model and carrying out weighted least square solution;
Performing clock difference calculation according to the single epoch observation data, and performing multi epoch observation data screening by comparing the difference between the receiver clock difference obtained by the single epoch observation data calculation and the receiver clock difference obtained by the weighted least square calculation;
And re-performing multi-epoch weighted least square clock difference calculation according to the screened multi-epoch observation data and the multi-epoch weighted clock difference calculation model to obtain an optimized multi-epoch period starting time receiver clock difference and a receiver Zhong Piao in the multi-epoch period, calculating the optimized current epoch receiver clock difference, correcting the local time of the receiver, and completing time service.
A computer readable storage medium having stored thereon a computer program which when executed by a processor performs the steps of:
receiving multi-epoch observation data of the low-rail lead fusion signal by using a receiver, and acquiring the position coordinates of the receiver through Doppler positioning;
constructing a multi-epoch clock difference correlation model based on the multi-epoch Zhong Piao constant hypothesis;
Constructing a multi-epoch pseudo-range observation equation set by combining the multi-epoch clock difference correlation model and the receiver position coordinates, weighting a least square solution form of the multi-epoch pseudo-range observation equation set according to the comprehensive error estimation of different epochs in the clock difference solution process, constructing a multi-epoch weighted clock difference solution model and carrying out weighted least square solution;
Performing clock difference calculation according to the single epoch observation data, and performing multi epoch observation data screening by comparing the difference between the receiver clock difference obtained by the single epoch observation data calculation and the receiver clock difference obtained by the weighted least square calculation;
And re-performing multi-epoch weighted least square clock difference calculation according to the screened multi-epoch observation data and the multi-epoch weighted clock difference calculation model to obtain an optimized multi-epoch period starting time receiver clock difference and a receiver Zhong Piao in the multi-epoch period, calculating the optimized current epoch receiver clock difference, correcting the local time of the receiver, and completing time service.
Compared with the prior art, the time service method, the device, the equipment and the medium based on the low-rail-pass fusion signal have the following beneficial effects:
1. the time service method and the time service system have the advantages that time service jump and abnormality possibly caused by single epoch observation data can be avoided through the combination of the multi-epoch observation data, time service stability is improved, meanwhile, a multi-epoch weighted clock difference resolving model is constructed and weighted least square resolving is carried out through considering comprehensive error estimation of different epochs in the clock difference resolving process, the influence of epochs with low observation quality on the clock difference resolving precision of a receiver can be reduced, and the clock difference resolving and time service precision of the receiver is improved.
2. The receiver clock difference obtained by comparing the single epoch observation data and the receiver clock difference obtained by the weighted least square solution can further screen high-quality multi epoch observation data to perform receiver clock difference optimization and local time correction, and time service precision is further improved.
Drawings
FIG. 1 is a flow chart of a timing method based on a low-rail-pass fusion signal in one embodiment;
FIG. 2 is a schematic diagram of a time service method based on a low-rail-pass fusion signal according to an embodiment;
FIG. 3 is a block diagram of a timing device based on a low-rail-pass fusion signal in one embodiment;
fig. 4 is an internal structural diagram of a computer device in one embodiment.
Detailed Description
The present application will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present application more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.
In one embodiment, as shown in fig. 1 and 2, a time service method based on a low-rail conductance fusion signal is provided, which includes the following steps:
Step S1, receiving multi-epoch observation data of the low-rail lead fusion signal by using a receiver, and acquiring the position coordinates of the receiver through Doppler positioning.
Because the low-orbit-conduction fusion signal is a time slot signal and the satellite signal receiving time is asynchronous, firstly, the receiver needs to receive multi-epoch observation data within a certain time span range, and then calculates the initial value of the receiver position according to the Doppler effect principle and performs Doppler positioning to obtain the position coordinate of the receiver.
And S2, constructing a multi-epoch clock difference correlation model based on the multi-epoch Zhong Piao constant assumption.
The assumption that the multiple epoch Zhong Piao is unchanged refers to that the receiver Zhong Piao is unchanged in a short period of time consisting of multiple epochs including the current epoch, and based on the assumption, the multi-epoch clock difference correlation can be modeled as a linear function, so that the number of unknown parameters is reduced, and the clock difference calculation efficiency of the subsequent receiver is improved.
And S3, constructing a multi-epoch pseudo-range observation equation set by combining the multi-epoch clock difference correlation model and the receiver position coordinates, weighting a least square solution form of the multi-epoch pseudo-range observation equation set according to the comprehensive error estimation of different epochs in the clock difference solution process, constructing a multi-epoch weighted clock difference solution model, and carrying out weighted least square solution.
Compared with the prior art, the receiver clock difference calculation is carried out based on the observation data of one satellite in the current epoch, the multi-epoch pseudo-range observation equation set constructed by the application can fully utilize the multi-epoch observation data, and the problem that the time service precision requirement is difficult to meet when the single epoch observation data is abnormal is avoided. Meanwhile, a multi-epoch weighted clock difference resolving model is constructed according to the comprehensive error estimation of different epochs in the clock difference resolving process, weighted least square resolving is carried out, quality difference of the receiver on the observation data of different satellites in different epochs can be considered, interference of low-quality observation is reduced, and clock difference resolving precision of the receiver is improved.
And S4, performing clock difference calculation according to the single epoch observation data, and performing multi epoch observation data screening by comparing the difference between the receiver clock difference obtained by the single epoch observation data calculation and the receiver clock difference obtained by the weighted least square calculation.
If abnormal values exist in the selected multi-epoch data, the clock difference calculated by the weighted least square solution and the clock difference calculated by the single-epoch observation data deviate, and the calculation accuracy of the clock difference of the receiver is affected, so that the abnormal observation data are removed through data screening, and the calculation accuracy of the clock difference of the receiver can be further optimized.
And S5, re-carrying out multi-epoch weighted least square clock difference calculation according to the screened multi-epoch observation data and the multi-epoch weighted clock difference calculation model to obtain an optimized multi-epoch period starting time receiver clock difference and an optimized multi-epoch period receiver Zhong Piao, calculating the optimized current epoch receiver clock difference, correcting the local time of the receiver, and completing time service.
According to the time service method based on the low-rail-pass fusion signal, multi-epoch observation data are fully utilized, the quality difference of the observation data of different epochs is considered to carry out receiver clock-difference weighted least square solution, and meanwhile abnormal observation data which possibly exist are removed, so that time service precision and stability can be remarkably improved compared with the traditional method.
In one embodiment, step S1 specifically includes first receiving, by a receiver, multi-epoch observation data within a certain time span range of the low-orbit guided fusion signal, where the multi-epoch observation data includes a plurality of sets of information including satellite positions, satellite speeds, doppler frequency observables, pseudo-range observables, and error correction parameters. Then, after receiving at least 4 sets of observation data, acquiring a receiver position initial value and a receiver Zhong Piao initial value by adopting an initial value search algorithm, establishing a Doppler positioning equation set in parallel, and acquiring a receiver three-dimensional position coordinate and a receiver Zhong Piao by solving through a Newton iteration method.
Specifically, a grid-based initial value search algorithm is adopted, satellites receiving signals are subjected to equidistant grid division on the surface area covered by the signals, and then least square solution is carried out on grids one by one, so that a receiver position initial value and a receiver Zhong Piao initial value are obtained through search.
Reconstructing a receiver static instantaneous Doppler observation equation expressed as:
;
Wherein, the In order to be a doppler frequency,For three-dimensional position coordinates by the receiverAnd a receiver Zhong PiaoThe four dimensions of the structure are subject to unknowns,For the doppler frequency measurement error,For the frequency of the transmitted signal of the satellite,In order to be the speed of motion of the satellite,In the form of satellite position coordinates,Is the speed of light.
Taking four-dimensional unknown data into consideration, constructing a Doppler positioning equation set simultaneously after receiving at least 4 sets of observation data, and obtaining three-dimensional position coordinates of a receiver through solving by Newton iteration methodAnd a receiver Zhong Piao。
In one embodiment, step S2 includes assuming that the receiver Zhong Piao is within a short period of time of the selected one epochUnchanged, a multi-epoch clock difference correlation model is constructed, expressed as:
;
Wherein, the Receiver clock skew for the ith epoch,For the receiver clock difference initial value at the start of the selected multi-epoch period,For the time when the receiver receives the i-th epoch observation,For the time when the receiver receives the selected observation data at the start of the multi-epoch period,,The first epoch is also referred to as the current epoch. It should be noted that, although the receiver Zhong Piao solution result has been obtained through doppler positioning in the step S1 of the time service method based on the low-rail lead fusion signal, the use of the receiver Zhong Piao solution result will affect the receiver clock error solution accuracy due to the insufficient measurement accuracy of the doppler frequency of the lead fusion signal. Thus, in modeling multi-epoch clock differences, the receiver Zhong PiaoStill considered as an unknown.
In one embodiment, step S3 specifically includes:
Firstly, constructing a multi-epoch pseudo-range observation equation set by combining a multi-epoch clock difference correlation model and receiver position coordinates, wherein a single epoch pseudo-range observation equation in the multi-epoch pseudo-range observation equation set is expressed as:
;
Wherein, the The pseudorange values measured for the ith epoch receiver and corrected for satellite clock differences, ionospheric delays and tropospheric delays,The three-dimensional position coordinates of the receiver obtained for the doppler positioning solution,For the satellite position coordinates of the ith epoch,The pseudorange measurement error for the ith epoch.
The multi-epoch pseudo-range observation equation set consisting of simultaneous pseudo-range observation equations can be alignedAndSolving and substituting into a multi-epoch clock difference correlation model to obtain the receiver clock difference of the current epoch. Compared with the calculation of single epoch observation data, the time service jump and abnormality possibly caused by single epoch observation data can be avoided by combining the multi epoch observation data, and the time service stability is improved.
Further, consider that for the clock error resolution process, the primary errors are receiver position errors, pseudorange measurement errors, and atmospheric propagation errors. The receiver position is obtained through Doppler positioning, the error is a deterministic error in the clock error resolving process, the influence on the calendar data is consistent, and the weight can be given without consideration. And the receiver has different precision of errors such as pseudo-range measurement errors, atmospheric propagation errors and the like of different satellites in different epochs, and a reasonable weighting matrix is constructed based on a multi-epoch pseudo-range observation equation set which is formed by the pseudo-range measurement errors and the atmospheric propagation errors in the clock error calculation process, so that the clock error calculation precision is improved.
The pseudo-range measurement error is mainly the measurement accuracy of the code phase, is highly correlated with the satellite signal receiving quality, and can be obtained by estimating the carrier-to-noise ratio of the receiver signal, and the pseudo-range measurement error standard deviation of a satellite in the ith epoch in the clock error calculation process is expressed as:
;
Wherein, the For pseudorange measurements of receiver related parameters,The carrier-to-noise ratio of the received signal for the ith epoch.
In addition, the magnitude of the atmospheric propagation errors such as ionospheric delay and tropospheric delay are highly correlated with satellite elevation angles, and satellites with smaller satellite elevation angles generally have larger atmospheric propagation errors. The standard deviation of atmospheric propagation error of a satellite in the ith epoch in the clock difference resolving process is set asEstimation is performed by using an elevation empirical sine function model, which is specifically expressed as:
;
Wherein, the The satellite elevation angle of the ith epoch, a and b are set empirical values.
For the two types of random errors, the simplified assumption is that the random errors are independent and normally distributed from each other, and the statistical characteristics of the random errors are more met by adopting a square method and a root method for synthesis. Integrated error of the i-th epoch obtained after synthesisExpressed as:
。
Specifically, a weight matrix is constructed according to the integrated error of each epoch Expressed as:
;
Wherein, the The representation extracts the diagonal elements and,The weight of a satellite participating in weighted least square solution of the ith epoch is represented, the formula shows that the epoch with larger comprehensive error is lower in assigned weight, the influence of the epoch with low observation quality on clock error solution precision is reduced, and time service precision is improved.
Further, converting the pseudo-range observation equation for each epoch in the multi-epoch pseudo-range observation equation set to:
;
a matrix form of a set of multi-epoch pseudorange observation equations may be established, expressed as:
;
Wherein, the Is an observation residual vector; Is a coefficient matrix, wherein the first column is the receiver clock difference at the selected starting time of the multi-epoch period The second column is the receiver Zhong PiaoCoefficients of (1), superscriptRepresenting a matrix transpose; Is a parameter to be estimated.
According to the solving formula of the least square method, the least square solving form of the multi-epoch pseudo-range observation equation set can be expressed as:
。
the weight matrix constructed by the method Substituting the model into a least square solution form of a multi-epoch pseudo-range observation equation set, and constructing and obtaining a multi-epoch weighted clock difference solution model, wherein the model is expressed as follows:
。
the weighted least square solution is carried out on the multi-epoch weighted clock difference solution model, and the calculation can be obtained AndAnd willAndSubstituting into a multi-epoch clock difference correlation model, and calculating to obtain the receiver clock difference obtained by each epoch weighted least square solutionWherein, the method comprises the steps of,,For the total number of epochs selected.
In one embodiment, step S4 specifically includes performing a clock-difference calculation according to the single epoch observation data, expressed as:
;
Wherein, the Representing the receiver clock difference obtained by solving the ith epoch through single epoch observation data.
Comparing one by oneReceiver clock error obtained by solving weighted least squareThe absolute value of the difference between the two values and the set threshold T, ifAnd eliminating the observation data of the ith epoch to obtain a group of screened multi-epoch observation data. The clock difference resolving precision of the receiver can be further optimized through the screened multi-epoch observation data, so that the time service precision can be remarkably improved.
In one embodiment, as shown in fig. 3, there is provided a time service device based on a low-rail-conductance fusion signal, including:
The data receiving and positioning module 301 is configured to receive multi-epoch observation data of the low-rail-guided fusion signal by using the receiver, and obtain the position coordinates of the receiver through doppler positioning.
The clock bias correlation modeling module 302 is configured to construct a multi-epoch clock bias correlation model based on the multi-epoch Zhong Piao constant hypothesis.
The multi-epoch weighted clock difference resolving module 303 is configured to construct a multi-epoch pseudo-range observation equation set by combining the multi-epoch clock difference correlation model and the receiver position coordinates, weight a least square resolving form of the multi-epoch pseudo-range observation equation set according to the comprehensive error estimates of different epochs in the clock difference resolving process, construct a multi-epoch weighted clock difference resolving model, and perform weighted least square resolving.
The data filtering module 304 is configured to perform clock difference calculation according to the single epoch observation data, and perform multi epoch observation data filtering by comparing a difference between the receiver clock difference obtained by the single epoch observation data calculation and the receiver clock difference obtained by the weighted least squares calculation.
The clock difference optimization and local time correction module 305 is configured to re-perform multi-epoch weighted least square clock difference calculation according to the screened multi-epoch observation data and the multi-epoch weighted clock difference calculation model, obtain an optimized multi-epoch period starting time receiver clock difference and an optimized multi-epoch period receiver Zhong Piao, calculate an optimized current epoch receiver clock difference, correct the receiver local time, and complete time service.
For specific limitation of the time service device based on the low-rail-conduction fusion signal, reference may be made to the limitation of the time service method based on the low-rail-conduction fusion signal hereinabove, and the description thereof will not be repeated here. All or part of each module in the time service device based on the low-rail-conductance fusion signal can be realized by software, hardware and a combination thereof. The above modules may be embedded in hardware or may be independent of a processor in the computer device, or may be stored in software in a memory in the computer device, so that the processor may call and execute operations corresponding to the above modules.
In one embodiment, a computer device is provided, which may be a terminal, and the internal structure of which may be as shown in fig. 4. The computer device includes a processor, a memory, a network interface, a display screen, and an input device connected by a system bus. Wherein the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The network interface of the computer device is used for communicating with an external terminal through a network connection. The computer program, when executed by a processor, implements a time service method based on a low-rail-pass fusion signal. The display screen of the computer equipment can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer equipment can be a touch layer covered on the display screen, can also be keys, a track ball or a touch pad arranged on the shell of the computer equipment, and can also be an external keyboard, a touch pad or a mouse and the like.
It will be appreciated by persons skilled in the art that the architecture shown in fig. 4 is merely a block diagram of some of the architecture relevant to the present inventive arrangements and is not limiting as to the computer device to which the present inventive arrangements are applicable, and that a particular computer device may include more or fewer components than shown, or may combine some of the components, or have a different arrangement of components.
In one embodiment, a computer device is provided comprising a memory storing a computer program and a processor that when executing the computer program performs the steps of:
receiving multi-epoch observation data of the low-rail lead fusion signal by using a receiver, and acquiring the position coordinates of the receiver through Doppler positioning;
constructing a multi-epoch clock difference correlation model based on the multi-epoch Zhong Piao constant hypothesis;
Constructing a multi-epoch pseudo-range observation equation set by combining the multi-epoch clock difference correlation model and the receiver position coordinates, weighting a least square solution form of the multi-epoch pseudo-range observation equation set according to the comprehensive error estimation of different epochs in the clock difference solution process, constructing a multi-epoch weighted clock difference solution model and carrying out weighted least square solution;
Performing clock difference calculation according to the single epoch observation data, and performing multi epoch observation data screening by comparing the difference between the receiver clock difference obtained by the single epoch observation data calculation and the receiver clock difference obtained by the weighted least square calculation;
And re-performing multi-epoch weighted least square clock difference calculation according to the screened multi-epoch observation data and the multi-epoch weighted clock difference calculation model to obtain an optimized multi-epoch period starting time receiver clock difference and a receiver Zhong Piao in the multi-epoch period, calculating the optimized current epoch receiver clock difference, correcting the local time of the receiver, and completing time service.
In one embodiment, a computer readable storage medium is provided having a computer program stored thereon, which when executed by a processor, performs the steps of:
receiving multi-epoch observation data of the low-rail lead fusion signal by using a receiver, and acquiring the position coordinates of the receiver through Doppler positioning;
constructing a multi-epoch clock difference correlation model based on the multi-epoch Zhong Piao constant hypothesis;
Constructing a multi-epoch pseudo-range observation equation set by combining the multi-epoch clock difference correlation model and the receiver position coordinates, weighting a least square solution form of the multi-epoch pseudo-range observation equation set according to the comprehensive error estimation of different epochs in the clock difference solution process, constructing a multi-epoch weighted clock difference solution model and carrying out weighted least square solution;
Performing clock difference calculation according to the single epoch observation data, and performing multi epoch observation data screening by comparing the difference between the receiver clock difference obtained by the single epoch observation data calculation and the receiver clock difference obtained by the weighted least square calculation;
And re-performing multi-epoch weighted least square clock difference calculation according to the screened multi-epoch observation data and the multi-epoch weighted clock difference calculation model to obtain an optimized multi-epoch period starting time receiver clock difference and a receiver Zhong Piao in the multi-epoch period, calculating the optimized current epoch receiver clock difference, correcting the local time of the receiver, and completing time service.
Those skilled in the art will appreciate that implementing all or part of the above described methods may be accomplished by way of a computer program stored on a non-transitory computer readable storage medium, which when executed, may comprise the steps of the embodiments of the methods described above. Any reference to memory, storage, database, or other medium used in embodiments provided herein may include non-volatile and/or volatile memory. The nonvolatile memory can include Read Only Memory (ROM), programmable ROM (PROM), electrically Programmable ROM (EPROM), electrically Erasable Programmable ROM (EEPROM), or flash memory. Volatile memory can include Random Access Memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms such as Static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double Data Rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (SYNCHLINK) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), among others.
The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples merely represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the present application. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application.
Claims (9)
1. A time service method based on a low-rail-pass fusion signal, the method comprising:
receiving multi-epoch observation data of the low-rail lead fusion signal by using a receiver, and acquiring the position coordinates of the receiver through Doppler positioning;
constructing a multi-epoch clock difference correlation model based on the multi-epoch Zhong Piao constant hypothesis;
Constructing a multi-epoch pseudo-range observation equation set by combining the multi-epoch clock difference correlation model and the receiver position coordinates, weighting the least square solution form of the multi-epoch pseudo-range observation equation set according to the comprehensive error estimation of different epochs in the clock difference solution process, constructing a multi-epoch weighted clock difference solution model and carrying out weighted least square solution, wherein the comprehensive error estimation is to estimate the pseudo-range measurement error and the atmospheric propagation error in the clock difference solution process of each epoch, and synthesizing the comprehensive error of each epoch based on a method and a root method;
Performing clock difference calculation according to the single epoch observation data, and performing multi epoch observation data screening by comparing the difference between the receiver clock difference obtained by the single epoch observation data calculation and the receiver clock difference obtained by the weighted least square calculation;
Re-performing multi-epoch weighted least square clock difference calculation according to the screened multi-epoch observation data and the multi-epoch weighted clock difference calculation model to obtain an optimized multi-epoch period starting time receiver clock difference and a multi-epoch period receiver Zhong Piao, calculating the optimized current epoch receiver clock difference, correcting the local time of the receiver, and completing time service;
Wherein, the clock difference is calculated according to the single epoch observation data, and performing multi-epoch observation data screening by comparing a difference between a receiver clock difference obtained by single epoch observation data calculation and a receiver clock difference obtained by weighted least squares calculation, comprising:
Performing clock difference calculation according to single epoch observation data, wherein the clock difference calculation is expressed as follows:
;
Wherein, the Representing the receiver clock difference obtained by solving the single epoch observation data for the i-th epoch,The pseudorange values measured for the ith epoch receiver and corrected for satellite clock differences, ionospheric delays and tropospheric delays,The three-dimensional position coordinates of the receiver obtained for the doppler positioning solution,Satellite position coordinates for the ith epoch;
Comparing one by one Receiver clock error obtained by solving weighted least squareThe absolute value of the difference between the two values and the set threshold T, ifAnd eliminating the observation data of the ith epoch to obtain a group of screened multi-epoch observation data.
2. The method of claim 1, wherein receiving multi-epoch observations of the low-rail-pass fusion signal with the receiver and obtaining receiver position coordinates via doppler positioning comprises:
Receiving multi-epoch observation data within a certain time span range of the low-orbit guided fusion signal by using a receiver, wherein the multi-epoch observation data comprises a plurality of groups of satellite positions, satellite speeds, doppler frequency observables, pseudo-range observables and error correction parameters;
after receiving at least 4 groups of observation data, acquiring a receiver position initial value and a receiver Zhong Piao initial value by adopting an initial value search algorithm, establishing a Doppler positioning equation set in parallel, and acquiring a receiver three-dimensional position coordinate and a receiver Zhong Piao by solving through a Newton iteration method.
3. The method of claim 2, wherein obtaining the initial values of the receiver position and the initial values of the receiver Zhong Piao using an initial value search algorithm, constructing a set of doppler positioning equations in parallel, and obtaining the three-dimensional position coordinates of the receiver and the receiver Zhong Piao by solving using newton's iteration method, comprises:
The method comprises the steps of adopting a grid-based initial value searching algorithm, carrying out equidistant grid division on a satellite receiving signals, carrying out least square calculation on the ground surface area covered by the signals, and searching one by one to obtain a receiver position initial value and a receiver Zhong Piao initial value;
Constructing a receiver static instantaneous Doppler observation equation expressed as:
;
Wherein, the In order to be a doppler frequency,For three-dimensional position coordinates by the receiverAnd a receiver Zhong PiaoThe four dimensions of the structure are subject to unknowns,For the doppler frequency measurement error,For the frequency of the transmitted signal of the satellite,In order to be the speed of motion of the satellite,In the form of satellite position coordinates,Is the speed of light;
Taking four-dimensional unknown data into consideration, constructing a Doppler positioning equation set simultaneously after receiving at least 4 sets of observation data, and obtaining three-dimensional position coordinates of a receiver through solving by Newton iteration method And a receiver Zhong Piao。
4. A method according to any one of claims 1 to 3, wherein constructing a multi-epoch clock-difference correlation model based on a multi-epoch Zhong Piao constant hypothesis comprises:
Assume that receiver Zhong Piao is selected for a short period of time consisting of one epoch UnchangedFor unknowns, a multi-epoch clock difference correlation model is constructed, expressed as:
;
Wherein, the Receiver clock skew for the ith epoch,For the receiver clock difference initial value at the start of the selected multi-epoch period,For the time when the receiver receives the i-th epoch observation,For the time when the receiver receives the selected observation data at the start of the multi-epoch period,,The first epoch is also referred to as the current epoch.
5. The method of claim 4, wherein a system of multi-epoch pseudo-range observation equations is constructed by combining the multi-epoch clock difference correlation model and receiver position coordinates, wherein pseudo-range observation equations for individual epochs in the system of multi-epoch pseudo-range observation equations are expressed as:
;
Wherein, the The pseudorange values measured for the ith epoch receiver and corrected for satellite clock differences, ionospheric delays and tropospheric delays,The three-dimensional position coordinates of the receiver obtained for the doppler positioning solution,For the satellite position coordinates of the ith epoch,The pseudorange measurement error for the ith epoch.
6. The method of claim 5, wherein weighting the least squares solution of the set of multi-epoch pseudo-range observation equations based on the integrated error estimates for different epochs during the clock-difference solution, constructing a multi-epoch weighted clock-difference solution model and performing a weighted least squares solution, comprising:
Pseudo-range measurement error and atmospheric propagation error in the process of calculating the clock difference of the ith epoch are estimated, and the comprehensive error of the ith epoch is synthesized based on a square method and a root method Expressed as:
;
Wherein, the Representing the standard deviation of the pseudorange measurement error for a satellite at the ith epoch,For pseudorange measurements of receiver related parameters,Carrier-to-noise ratio of the received signal for the ith epoch; the standard deviation of the atmospheric propagation error for a satellite at the ith epoch, The satellite elevation angle of the ith epoch, and a and b are set empirical values;
constructing a weight matrix according to the comprehensive error of each epoch Expressed as:
;
Wherein, the The representation extracts the diagonal elements and,A weight representing the participation of a satellite in the weighted least squares solution of the ith epoch;
converting the multi-epoch pseudo-range observation equation set into a least square solution form and substituting the solution into the weight matrix Constructing and obtaining a multi-epoch weighted clock difference solution model, which is expressed as:
;
Wherein, the Is a coefficient matrix, wherein the first column is the receiver clock difference at the selected starting time of the multi-epoch periodThe second column is the receiver Zhong PiaoCoefficients of (1), superscriptThe transpose of the matrix is represented,For the time when the receiver receives the i-th epoch observation,;Is an observation residual vector;
the multi-epoch weighted clock difference solution model is subjected to weighted least square solution, and is calculated to obtain AndAnd willAndSubstituting into a multi-epoch clock difference correlation model, and calculating to obtain the receiver clock difference obtained by each epoch weighted least square solutionWherein, the method comprises the steps of,,For the total number of epochs selected.
7. A time service device based on a low-rail-pass fusion signal, the device comprising:
the data receiving and positioning module is used for receiving multi-epoch observation data of the low-rail communication fusion signal by using the receiver and acquiring the position coordinates of the receiver through Doppler positioning;
The clock difference correlation modeling module is used for constructing a multi-epoch clock difference correlation model based on the assumption that the multi-epoch Zhong Piao is unchanged;
The multi-epoch weighted clock difference resolving module is used for constructing a multi-epoch pseudo-range observation equation set by combining the multi-epoch clock difference correlation model and the position coordinates of the receiver, weighting the least square resolving form of the multi-epoch pseudo-range observation equation set according to the comprehensive error estimation of different epochs in the clock difference resolving process, constructing a multi-epoch weighted clock difference resolving model and carrying out weighted least square resolving, wherein the comprehensive error estimation is used for estimating pseudo-range measurement errors and atmospheric propagation errors in the clock difference resolving process of each epoch, and synthesizing the comprehensive errors of each epoch based on a square and root method;
The data screening module is used for carrying out clock difference calculation according to the single epoch observation data, and carrying out multi epoch observation data screening by comparing the difference between the receiver clock difference obtained by the single epoch observation data calculation and the receiver clock difference obtained by the weighted least square calculation;
The clock difference optimization and local time correction module is used for carrying out multi-epoch weighted least square clock difference calculation again according to the screened multi-epoch observation data and the multi-epoch weighted clock difference calculation model to obtain an optimized multi-epoch period starting time receiver clock difference and an optimized multi-epoch period receiver Zhong Piao, calculating the optimized current epoch receiver clock difference, correcting the local time of the receiver, and completing time service;
the data screening module is specifically used for:
Performing clock difference calculation according to single epoch observation data, wherein the clock difference calculation is expressed as follows:
;
Wherein, the Representing the receiver clock difference obtained by solving the single epoch observation data for the i-th epoch,The pseudorange values measured for the ith epoch receiver and corrected for satellite clock differences, ionospheric delays and tropospheric delays,The three-dimensional position coordinates of the receiver obtained for the doppler positioning solution,Satellite position coordinates for the ith epoch;
Comparing one by one Receiver clock error obtained by solving weighted least squareThe absolute value of the difference between the two values and the set threshold T, ifAnd eliminating the observation data of the ith epoch to obtain a group of screened multi-epoch observation data.
8. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor implements the steps of the method of any of claims 1 to 6 when the computer program is executed.
9. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the steps of the method according to any one of claims 1 to 6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202511107853.XA CN120595333B (en) | 2025-08-08 | 2025-08-08 | Time service method, device, equipment and medium based on low-rail-pass-channel fusion signal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202511107853.XA CN120595333B (en) | 2025-08-08 | 2025-08-08 | Time service method, device, equipment and medium based on low-rail-pass-channel fusion signal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN120595333A CN120595333A (en) | 2025-09-05 |
| CN120595333B true CN120595333B (en) | 2025-10-14 |
Family
ID=96898600
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202511107853.XA Active CN120595333B (en) | 2025-08-08 | 2025-08-08 | Time service method, device, equipment and medium based on low-rail-pass-channel fusion signal |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN120595333B (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118938270A (en) * | 2024-07-31 | 2024-11-12 | 北京航空航天大学 | A low-orbit satellite joint positioning method and system for providing initial position |
| CN119916417A (en) * | 2025-04-02 | 2025-05-02 | 湖南中森通信科技有限公司 | Doppler positioning method and device for low-orbit communication satellite based on factor graph optimization |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118748834A (en) * | 2024-08-07 | 2024-10-08 | 北京航空航天大学 | 5G base station synchronization error reduction method and system based on multi-epoch joint positioning |
| CN118707571B (en) * | 2024-08-29 | 2024-11-15 | 湖南中森通信科技有限公司 | Ground terminal Doppler positioning method and device based on low-orbit communication satellite |
| CN119805517B (en) * | 2025-03-07 | 2025-05-30 | 北京邮电大学 | Positioning method, device and storage medium based on low-orbit satellite opportunistic signals |
| CN120428278A (en) * | 2025-05-16 | 2025-08-05 | 北京理工大学 | A method for aircraft positioning based on multi-epoch observations in asynchronous networks |
| CN120370360A (en) * | 2025-05-21 | 2025-07-25 | 中国电子科技集团公司第二十研究所 | Doppler and pseudo-range fusion positioning method and system for low-orbit satellite lead signals |
-
2025
- 2025-08-08 CN CN202511107853.XA patent/CN120595333B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118938270A (en) * | 2024-07-31 | 2024-11-12 | 北京航空航天大学 | A low-orbit satellite joint positioning method and system for providing initial position |
| CN119916417A (en) * | 2025-04-02 | 2025-05-02 | 湖南中森通信科技有限公司 | Doppler positioning method and device for low-orbit communication satellite based on factor graph optimization |
Also Published As
| Publication number | Publication date |
|---|---|
| CN120595333A (en) | 2025-09-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN115963522B (en) | A positioning method and terminal combining base station satellite data | |
| US8416133B2 (en) | System and method for compensating for faulty measurements | |
| US20220107427A1 (en) | System and method for gaussian process enhanced gnss corrections generation | |
| Amiri-Simkooei et al. | Application of least-squares variance component estimation to GPS observables | |
| EP4007928A1 (en) | System and method for gaussian process enhanced gnss corrections generation | |
| CN114966760B (en) | Ionosphere weighted non-differential non-combination PPP-RTK technology implementation method | |
| CN116540280B (en) | Comprehensive processing method and system for state domain correction information of multi-frequency satellite navigation data | |
| CN117055323A (en) | Star-based precise time service method and system based on Beidou/Galileo system fusion | |
| CN107966722B (en) | GNSS clock error resolving method | |
| CN112230254B (en) | Correction method and device for GPS carrier phase multipath error | |
| CN108802781A (en) | The acquisition methods of integer ambiguity | |
| CN119199921A (en) | A satellite positioning method and system with multi-frequency and multi-system anti-electromagnetic interference | |
| CN115308781B (en) | BDGIM-assisted phase smoothing pseudo-range high-precision time transfer method | |
| CN120595333B (en) | Time service method, device, equipment and medium based on low-rail-pass-channel fusion signal | |
| Andersen | Multi-level arc combination with stochastic parameters | |
| CN115327593A (en) | Positioning method and system based on unmanned aerial vehicle and storage medium | |
| CN113534206B (en) | Quick selection method for access virtual reference station based on Beidou foundation enhancement system | |
| Mikschi et al. | Unconstrained estimation of VLBI global observing system station coordinates | |
| CN120254916B (en) | Doppler differential positioning method, device, equipment and medium for low-orbit satellite | |
| CN105891859A (en) | Satellite navigation PVT calculation method, corresponding chip and module | |
| CN118818540B (en) | A receiver clock bias prediction method, apparatus, device, and storage medium | |
| CN114509797B (en) | Method, system and storage medium for fast fixing ambiguity between reference stations | |
| Tretyak et al. | Modified parameter methods of researching GNSS networks with correlative measurements and systematic errors | |
| CN119355765B (en) | A method for estimating GNSS receiver observation noise | |
| CN118688832B (en) | A method and system for monitoring accuracy of data differential post-processing in a navigation system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |