CN119126163B

CN119126163B - Multi-model fusion precise single-point positioning time service method, device and receiver

Info

Publication number: CN119126163B
Application number: CN202411637009.3A
Authority: CN
Inventors: 吴志远; 郭军; 李叶坤; 张建
Original assignee: Hunan Zhongsen Communication Technology Co ltd
Current assignee: Hunan Zhongsen Communication Technology Co ltd
Priority date: 2024-11-15
Filing date: 2024-11-15
Publication date: 2025-02-07
Anticipated expiration: 2044-11-15
Also published as: CN119126163A

Abstract

The present application relates to a multi-model fused precise point positioning and timing method, device and receiver. The IF model and the Uofc model are fused to solve the problem that the current IF model cannot establish the observation equation due to the lack of a certain frequency signal of the satellite in a complex environment. In addition, in the model fusion, the receiver hardware delay deviation parameter is designed to solve the problem of receiver clock error difference when the IF model and the Uofc model are integrated for PPP solution. The present invention fuses the IF model and the Uofc model for PPP solution, which can fully utilize all satellite resources observed by the receiver under normal conditions, and avoid the problem of interruption or jump in PPP positioning and timing when the satellite signal is interfered.

Description

Multi-model fusion precise single-point positioning time service method, device and receiver

Technical Field

The application relates to the technical field of navigation positioning time service, in particular to a precision single-point positioning time service method, device and receiver with multi-model fusion.

Background

The precise single-point positioning is used as a novel absolute positioning mode, and high-precision positioning and time service information can be provided all the day and the day by receiving the orbit and clock error parameters broadcast by the satellite in real time. At present, a dual-frequency IF model is generally adopted for PPP calculation, and the model can effectively eliminate a first-order ionosphere and weaken the influence of ionosphere scintillation change on positioning time service through combination of two frequencies. However, the model has high requirements on the frequency consistency of the received satellite, and IF model processing can be adopted when two frequency signals are received simultaneously for a certain satellite.

In practical engineering application, partial or all satellite double-frequency signal receiving incompleteness phenomenon often occurs, for example, when satellite signals are interfered by external signal sources, the receiver can only receive one frequency signal, in addition, not all the receivers have excellent baseband performance, the satellite double-frequency signal receiving device is limited by environments with serious shielding such as cost, urban canyons and the like, sometimes the receivers can only receive single frequencies of certain satellites, and satellite observation values of the single frequencies cannot participate in normal PPP calculation. The half sum (Uofc) model reduces both the noise of the combined observations and eliminates the effects of first order ionospheric delay by combining the pseudorange phase observations of a single frequency, but requires simultaneous estimation of ambiguity parameters on both frequencies.

The prior researches also design some technical schemes mainly aiming at the situations of inconsistent satellite frequency signals of received satellites, inconsistent satellite broadcasting frequencies of BDS-2 and BDS-3 transmitted at different stages caused by GPS modernization, and the like, but mainly aiming at a three-frequency ionosphere model, the model still needs to normally receive satellite signals with at least two different frequencies by combining three frequency observation values at one time, and some scholars propose to participate in PPP (point-to-point) solution of an IF (intermediate frequency) model after correcting ionosphere errors by using an ionosphere model, but are limited by the precision of the ionosphere model and a pseudo-range observation value, and the scheme is not obvious in precision improvement.

Disclosure of Invention

In view of the foregoing, it is desirable to provide a method, an apparatus and a receiver for positioning and timing precision single-point fusion, which can solve the problem of positioning and timing when a part or all satellites receive only single frequency observation data.

A precision single point positioning time service method of multi-model fusion, the method comprising:

Establishing a function model for data processing in precise single-point positioning time service, wherein the function model comprises an IF model and a Uofc model, the IF model is used for processing double-frequency data, and the Uofc model is used for processing single-frequency data;

obtaining a receiver hardware delay deviation parameter fused between the IF model and the Uofc model according to the clock difference between the receiver clock difference parameter of the IF model and the receiver clock difference parameter of the Uofc model;

And according to the receiver hardware delay deviation parameters, fusing the IF model and the Uofc model to obtain a fused model, processing satellite signals which receive single-frequency observations through a Uofc model in the fused model, and processing the satellite signals which completely receive double-frequency observations through the IF model in the fused model in precise single-point positioning time service.

In one embodiment, the method further comprises obtaining a receiver hardware delay deviation parameter fused between the IF model and the Uofc model by adopting a random walk estimation method according to the clock difference between the receiver clock difference parameter of the IF model and the receiver clock difference parameter of the Uofc model.

In one embodiment, the method further comprises fusing the IF model and the Uofc model according to the receiver hardware delay deviation parameter to obtain an observation equation of the fused model, wherein the observation equation is as follows:

;

Wherein, AndThe combined pseudorange and phase observations in the IF model,Representing a single frequencyIs used to combine the observations of the pseudo-range phase combinations,Indicating that the receiver is able to receive satellites of two frequency observations,Then it is meant that only a single frequency observation can be received for a satellite,Is a three-dimensional position coordinate parameter of the ground point,For the receiver clock-difference parameter,,Indicating the true receiver clock difference,Representing the combined pseudorange hardware delays,Is the receiver hardware delay deviation parameter; tropospheric delay parameters for an estimated zenith direction of the receiver; The ambiguity parameters are combined for the IF model, Is the frequencyIs used to determine the degree of ambiguity parameters of the (c),AndThe observed noise of the combined pseudoranges and the combined phases respectively,Is a single frequency pseudorange phase combination noise of Uofc model.

In one embodiment, the method further comprises the step of obtaining a receiver hardware delay deviation parameter fused between the IF model and the Uofc model by adopting a random walk estimation method, wherein the receiver hardware delay deviation parameter is as follows:

;

for a single frequency Is a pseudo-range hardware delay.

In one embodiment, the method further comprises the step of back-pushing the ambiguity as follows according to the combined observed value of the current epoch, the PPP related parameters of the receiver Zhong Piao and the previous epoch:

;

Wherein, AndRepresenting the current epoch and the previous epoch.

In one embodiment, the method further comprises, under static conditions,;

In the case of a dynamic condition of the system,;Representing the velocity of the current epoch,A time interval representing a current epoch and a previous epoch;, a receiver clock difference parameter representing a previous epoch, A Zhong Piao value representing the current epoch,AndAre all obtained by Doppler velocimetry.

In one embodiment, the method further comprises that when the received satellite signal is changed from the double-frequency observed value to the single-frequency observed value or the single-frequency observed value is restored to the double-frequency observed value, the ambiguity parameters are hopped, and the ambiguity calculation mode is combined in the double frequencyAnd single frequencySwitching between.

A precision single point positioning timing device for multi-model fusion, the device comprising:

The function model building module is used for building a function model for data processing in precise single-point positioning time service, wherein the function model comprises an IF model and a Uofc model, the IF model is used for processing double-frequency data, and the Uofc model is used for processing single-frequency data;

the deviation calculation module is used for obtaining a receiver hardware delay deviation parameter fused between the IF model and the Uofc model according to the clock difference between the receiver clock difference parameter of the IF model and the receiver clock difference parameter of the Uofc model;

And the fusion positioning time service module is used for fusing the IF model and the Uofc model according to the receiver hardware delay deviation parameter to obtain a fusion model, so that in the precise single-point positioning time service, satellite signals of single frequency observation values are only received through Uofc model processing in the fusion model, and satellite signals of double frequency observation values can be completely received through IF model processing in the fusion model.

A receiver comprising a memory storing a computer program and a processor implementing the following steps when executing the computer program:

And according to the receiver hardware delay deviation parameters, fusing the IF model and the Uofc model to obtain a fused model, processing satellite signals which only receive single-frequency observation values through a Uofc model in the fused model, and processing satellite signals which can completely receive double-frequency observation values through the IF model in the fused model in precise single-point positioning time service.

A computer readable storage medium having stored thereon a computer program which when executed by a processor performs the steps of:

According to the multi-model fusion precise single-point positioning time service method, device and receiver, as for the design of the function model, the problem that an observation equation cannot be established due to the fact that an IF model faces to the defect of a satellite certain frequency signal in a complex environment is solved by adopting a method of fusion of the IF model and the Uofc model, in addition, in the model fusion, the receiver hardware delay deviation parameter is designed, and the problem of receiver clock difference existing when the fusion of the IF model and the Uofc model is subjected to PPP (point-to-point protocol) solution is solved. The invention combines the IF model and Uofc model to perform PPP calculation, not only fully utilizes all satellite resources observed by a receiver under normal environment, but also can avoid the problem of interruption or jump of PPP positioning time service when satellite signals are interfered.

Drawings

FIG. 1 is a general flow chart of a precise single point positioning timing method in one embodiment;

FIG. 2 is a flow chart of a precise single point positioning timing method of multi-model fusion in one embodiment;

FIG. 3 is a flow diagram of a fusion model in one embodiment;

FIG. 4 is a flowchart of calculating ambiguity parameters in another embodiment;

FIG. 5 is a block diagram of a multi-model fusion precision single point positioning timing device in one embodiment;

Fig. 6 is an internal structural diagram of a receiver 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.

The precise single-point positioning time service method of the multi-model fusion can be applied to a processing flow shown in figure 1. The PPP technology is to establish a correct function model through pseudo-range phase observation data acquired by a receiver of a single measuring station, and to continuously and iteratively calculate parameters such as position clock difference by adopting Kalman filtering, so as to provide coordinates and time information for a user in real time.

In one embodiment, as shown in fig. 2, a multi-model fusion precise single point positioning time service method is provided, mainly through the steps of improving the function model in the method in fig. 1, which comprises the following steps:

step 202, a function model for data processing in precise single point positioning time service is established.

The function model comprises an IF model and a Uofc model, wherein the IF model is used for processing double-frequency data, and the Uofc model is used for processing single-frequency data.

The IF model consists of two parts, namely a combined pseudo-range observation equation and a combined phase observation equation:

;

wherein: And The combined pseudorange and phase observations in the IF model,Is a three-dimensional position coordinate parameter of the ground point,The receiver clock error parameter is formed by combining the true receiver clock error and the combined pseudo-range hardware delay of the receiver end, namely;Tropospheric delay parameters for an estimated zenith direction of the receiver; the ambiguity parameters are combined for the IF model. In addition, in the case of the optical fiber, AndThe observed noise of the combined pseudoranges and the combined phases, respectively.

The IF model eliminates the first-order ionosphere delay term, so that the correlation between the IF model and the receiver clock error parameter can be avoided, and the time service stability is ensured.

The Uofc model, i.e., the semi-sum model, is an ionosphere model, which is different from the IF model in that it does not combine observations of two different frequencies, but rather uses the characteristics of their ionospheric delay term signs for the single frequency pseudo-range phase observations, adds the pseudo-range and phase observations and divides them by 2, i.e., the first order ionospheric delay term is eliminated, and the pseudo-range phase combination observation equation for the Uofc model is:

;

wherein: representing a single frequency Is used to combine the observations of the pseudo-range phase combinations,The receiver clock error parameter of the half sum model is obtained by true receiver clock error and receiver endThe frequency pseudo-range hardware delays being combined, i.e;Is the ambiguity parameter of the frequency, andIs a difference formed by combining two frequencies,Is a single frequency ambiguity parameter; Is single frequency pseudo-range phase combination noise of Uofc model, and the rest parameters are the same as IF model.

And 204, obtaining the receiver hardware delay deviation parameter fusing the IF model and the Uofc model according to the clock difference between the receiver clock difference parameter of the IF model and the receiver clock difference parameter of the Uofc model.

It is apparent from the estimated parameters in the observation equations of the IF model and Uofc model that there is only a difference between the clock difference parameter and the ambiguity parameter. For the clock-difference parameter, in the IF modelAnd Uofc modelEssentially only the second additional item is different, whetherOr is alsoBoth related to the pseudorange hardware delay at the receiver. The prior art shows that the various frequency pseudorange hardware delays at the receiver end exhibit a more stable state as a whole, i.eAndThe difference between them can be used to compensate for errors in the Kalman filtering of PPP with a constant estimate or with a random walk estimate.

And 206, according to the receiver hardware delay deviation parameters, fusing the IF model and the Uofc model to obtain a fused model, processing satellite signals which only receive single-frequency observations through a Uofc model in the fused model, and processing satellite signals which can completely receive double-frequency observations through the IF model in the fused model.

In the multi-model fusion precise single-point positioning time service method, the function model is designed by adopting the fusion mode of the IF model and the Uofc model, so that the problem that an observation equation cannot be established due to the fact that a certain frequency signal of a satellite is lost in a complex environment in the prior IF model is solved. The invention combines the IF model and Uofc model to perform PPP calculation, not only fully utilizes all satellite resources observed by a receiver under normal environment, but also can avoid the problem of interruption or jump of PPP positioning time service when satellite signals are interfered.

In one embodiment, as shown in fig. 1, the overall flow of precise single point positioning timing is illustrated.

1. Data preprocessing

The receiver demodulates satellite signals and decodes the satellite signals into various required observed data, namely pseudo-range observed values, phase observed values, doppler observed values and satellite data, namely orbit correction, clock correction and DCB correction.

2. Single point positioning

Before PPP calculation, SPP calculation, which is single-point positioning, is needed, and the SPP is divided into two parts, namely 1, obtaining rough coordinates and receiver clock error by using pseudo-range observation value to carry out least square calculation, and 2, obtaining more accurate speed and Zhong Piao by using Doppler observation value to carry out least square calculation.

1. Establishing a mathematical model

The mathematical model of PPP is divided into a function model and a random model, wherein the function model represents the function relation between the parameters to be estimated and the observed values, and the random model represents the parameters to be estimated and the statistical characteristics of the parameters to be estimated and the parameters. The invention mainly improves the function model.

In one embodiment, as shown in fig. 3, according to the receiver hardware delay deviation parameter, the IF model and the Uofc model are fused, and the observation equation of the fused model is obtained as follows:

;

In another embodiment, to ensure consistency of the clock difference parameters between the two models, a random walk estimation method is used to obtain the receiver hardware delay bias parameters of the fused IF model and the Uofc model in order to more widely adapt to the performances of different receivers.

Specifically, by adopting a random walk estimation method, the receiver hardware delay deviation parameters of the fused IF model and Uofc model are as follows:

;

for a single frequency Is a pseudo-range hardware delay.

2. Kalman filtering

The Kalman filtering can pertinently adopt different estimation methods according to the characteristics of different parameters to be estimated, and obtain a parameter value with higher precision by continuously iterating the epoch observation value, wherein the Kalman filtering mainly comprises two parts of state prediction and measurement updating, the state prediction is to obtain a predicted value of the parameter to be estimated by adopting a corresponding state transition matrix according to the parameter value of the previous epoch, and the measurement updating is to update the predicted value of the parameter to be estimated by utilizing the observation value of the current epoch to obtain the parameter value to be estimated of the current epoch. Due to the nature of the phase ambiguity parameters, a constant estimation method is generally adopted.

Among the parameters to be estimated of the PPP, the phase ambiguity parameter is one of the important factors affecting the positioning time service precision. Whether the ambiguity parameter can be converged to a more accurate value or not rapidly determines the accuracy and stability of PPP time service precision. Due to ambient occlusion and loss of lock of the receiver phase-locked loop under continuous observation conditions, ambiguity is prone to cycle slip. At present, for ambiguity parameters with cycle slip, an IF model is initialized by subtracting phase observations of pseudo ranges after combination, uofc model is initialized by subtracting original pseudo ranges and phase observations of the frequency, then two times of ionospheric delay is subtracted, and ionospheric delay is calculated by adopting an ionospheric model. However, IF model initialization methods introduce combined pseudo-range noise, typically in meters, while Uofc models introduce pseudo-range noise and the ionospheric delay calculated using the ionospheric model deviates from its true value.

To solve the above problem, in one embodiment, the back-propagation ambiguity is as follows, according to the combined observed value of the current epoch, the PPP related parameters of the receiver Zhong Piao and the previous epoch:

;

Wherein, AndRepresenting the current epoch and the previous epoch.

In another embodiment, the parameters of the previous epoch can be directly used, and the position parameters can be used, because the tropospheric parameters and the hardware delay parameters of the receiver are stable in a short timeThen it is set according to different states that under static conditions, PPP position solution of last epoch can be used, i.e. Under dynamic conditions, it is necessary to calculate from the position of the previous epoch and the velocity of the current epoch, i.eThe clock-difference parameter is derived from the receiver Zhong Chazhi of the previous epoch and the Zhong Piao value of the current epoch, i.e,AndAre all obtained by Doppler velocimetry.

In one embodiment, when the received satellite signal changes from the dual-frequency observation value to the single-frequency observation value or the single-frequency observation value is restored to the dual-frequency observation value, the received satellite signal is equivalent to the jump of the ambiguity parameter, the ambiguity can be reversely deduced by adopting the method, and the ambiguity calculation mode is combined in the dual-frequency modeAnd single frequencySwitching between.

Specifically, as shown in fig. 4, the satellite received by the receiver can still be normally calculated under the condition that the satellite is changed from the dual-frequency observed value to the single-frequency observed value under the complex environment, and only the pseudo-range phase combination observed value with only a single frequency is contained in the fusion model. In addition, when the same satellite is changed from the double-frequency observation value to the single-frequency observation value, the ambiguity parameter is also determined byBecomes as followsIn the same way, if the satellite is recovered from the single-frequency observation value to the double-frequency observation value, the satellite is also considered as the satellite to have the cycle slip, and the ambiguity initialization method provided by the invention can be adopted to obtain more accurate ambiguity initial values in both cases, thereby ensuring the continuity of PPP (point-to-point protocol) calculation and the stability of time service.

It should be understood that, although the steps in the flowchart of fig. 2 are shown in sequence as indicated by the arrows, the steps are not necessarily performed in sequence as indicated by the arrows. The steps are not strictly limited to the order of execution unless explicitly recited herein, and the steps may be executed in other orders. Moreover, at least some of the steps in fig. 2 may include multiple sub-steps or stages that are not necessarily performed at the same time, but may be performed at different times, nor do the order in which the sub-steps or stages are performed necessarily performed in sequence, but may be performed alternately or alternately with at least a portion of the sub-steps or stages of other steps or other steps.

In one embodiment, as shown in fig. 5, a multi-model fused precise single-point positioning time service device is provided, which comprises a function model building module 502, a deviation calculating module 504 and a fused positioning time service module 506, wherein:

the function model building module 502 is used for building a function model for data processing in precise single-point positioning time service, wherein the function model comprises an IF model and a Uofc model, the IF model is used for processing double-frequency data, and the Uofc model is used for processing single-frequency data;

A deviation calculation module 504, configured to obtain a receiver hardware delay deviation parameter fused between the IF model and the Uofc model according to a clock difference between the receiver clock difference parameter of the IF model and the receiver clock difference parameter of the Uofc model;

And the fusion positioning time service module 506 is configured to fuse the IF model and the Uofc model according to the receiver hardware delay deviation parameter, so as to obtain a fusion model, so that in the precise single-point positioning time service, satellite signals of only a single frequency observation value are received through Uofc model processing in the fusion model, and satellite signals of double frequency observation values can be completely received through IF model processing in the fusion model.

In one embodiment, the bias calculation module 504 is further configured to obtain a receiver hardware delay bias parameter fused between the IF model and the Uofc model by adopting a random walk estimation method according to a clock difference between the receiver clock difference parameter of the IF model and the receiver clock difference parameter of the Uofc model.

In one embodiment, the fusion positioning time service module 506 is further configured to fuse the IF model and the Uofc model according to the receiver hardware delay deviation parameter, and obtain an observation equation of the fusion model as follows:

;

In one embodiment, the bias calculation module 504 is further configured to use a random walk estimation method to obtain the receiver hardware delay bias parameter that fuses the IF model and Uofc model as follows:

;

for a single frequency Is a pseudo-range hardware delay.

In one embodiment, the system further includes an ambiguity calculation module, configured to, based on the combined observed value of the current epoch, the receiver Zhong Piao, and the PPP related parameters of the previous epoch, back-calculate the ambiguity as:

;

Wherein, AndRepresenting the current epoch and the previous epoch.

In one of the embodiments, the paste calculation module is also used to calculate, under static conditions,;

In one embodiment, the ambiguity calculation module is further configured to, when the received satellite signal changes from the dual-frequency observed value to the single-frequency observed value or the single-frequency observed value is restored to the dual-frequency observed value, jump the ambiguity parameter, and combine the ambiguity calculation mode in the dual-frequency modeAnd single frequencySwitching between.

For specific limitation of the precise single-point positioning time service device of the multi-model fusion, reference may be made to the limitation of the precise single-point positioning time service method of the multi-model fusion hereinabove, and the description thereof will not be repeated here. All or part of each module in the multi-model fusion precise single-point positioning time service device can be realized by software, hardware and 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 receiver, which may be a terminal, is provided, and its internal structure may be as shown in fig. 6. The computer device includes a processor, a memory, a network interface, and a database connected by a system bus. Wherein the processor of the receiver 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, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The database of the receiver is used for storing single-frequency observation data and/or double-frequency observation data. The network interface of the receiver is used for communicating with an external terminal through a network connection. The computer program is executed by a processor to realize a precision single point positioning time service method of multi-model fusion.

It will be appreciated by those skilled in the art that the structure shown in FIG. 6 is merely a block diagram of some of the structures associated with the present inventive arrangements and is not limiting of the computer device to which the present inventive arrangements may be applied, 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 an embodiment, a receiver is provided comprising a memory storing a computer program and a processor implementing the steps of the method of the above embodiments when the computer program is executed.

In one embodiment, a computer readable storage medium is provided, on which a computer program is stored which, when executed by a processor, implements the steps of the method of the above embodiments.

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 illustrate only a few embodiments of the application, which are described in detail and are not to be construed as limiting the scope of the 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. Accordingly, the scope of protection of the present application is to be determined by the appended claims.

Claims

1. A multi-model fusion precise single-point positioning time service method is characterized by comprising the following steps:

According to the receiver hardware delay deviation parameter, fusing the IF model and the Uofc model to obtain a fused model, processing satellite signals which receive single frequency observation values through a Uofc model in the fused model, processing satellite signals which completely receive double frequency observation values through the IF model in the fused model, and according to the clock difference between the receiver clock difference parameter of the IF model and the receiver clock difference parameter of the Uofc model, obtaining the receiver hardware delay deviation parameter fused between the IF model and the Uofc model, wherein the method comprises the following steps:

according to the clock difference between the receiver clock difference parameter of the IF model and the receiver clock difference parameter of the Uofc model, adopting a random walk estimation method to obtain a receiver hardware delay deviation parameter fused between the IF model and the Uofc model;

According to the receiver hardware delay deviation parameter, fusing the IF model and the Uofc model to obtain a fused model, including:

according to the receiver hardware delay deviation parameter, fusing the IF model and the Uofc model to obtain an observation equation of the fused model, wherein the observation equation is as follows:

Wherein, AndThe combined pseudorange and phase observations in the IF model,A pseudo-range phase combination observation representing a single frequency f _j (j=1, 2), s ₁ representing satellites from which two frequency observations can be received by the receiver, s ₂ representing satellites from which only a single frequency observation can be received, X being the three-dimensional position coordinate parameter of the ground point,For the receiver clock-difference parameter,Dt _r denotes the true receiver clock difference, d _r,IF denotes the combined pseudorange hardware delay, Δclk _r is the receiver hardware delay bias parameter, T _r is the estimated tropospheric delay parameter in the receiver zenith direction; The ambiguity parameters are combined for the IF model, Is the ambiguity parameter for frequency f _j, ε _IF,P and ζ _IF,L are the combined pseudo-range and combined phase observed noise, respectively, η _j,Uofc is the single frequency pseudo-range phase combined noise for the Uofc model.

2. The method of claim 1, wherein using a random walk estimation method to obtain the receiver hardware delay bias parameter fused between the IF model and the Uofc model comprises:

And obtaining the receiver hardware delay deviation parameters fused between the IF model and the Uofc model by adopting a random walk estimation method, wherein the parameters are as follows:

d _r,j is the pseudorange hardware delay for a single frequency f _j.

3. The method according to claim 2, wherein the method further comprises:

based on the combined observations of the current epoch, the receiver Zhong Piao, and the PPP related parameters of the previous epoch, the reverse-push ambiguity is:

Where k and k-1 represent the current epoch and the previous epoch.

4. A method according to claim 3, characterized in that the method further comprises:

under static conditions, X ^k＝X^k-1;

under dynamic conditions, X ^k＝X^k-1+V^k*Δt^k,k-1;V^k represents the velocity of the current epoch, deltat ^k,k-1 represents the time interval between the current epoch and the previous epoch; a receiver clock difference parameter representing a previous epoch, Zhong Piao values representing the current epoch, V ^k andAre all obtained by Doppler velocimetry.

5. The method according to claim 3 or 4, characterized in that the method further comprises:

when the received satellite signal is changed from the double-frequency observed value to the single-frequency observed value or the single-frequency observed value is restored to the double-frequency observed value, the ambiguity parameters are hopped, and the ambiguity calculation mode is combined in the double frequency And single frequencySwitching between.

6. A multi-model fused precise single-point positioning time service device for realizing the multi-model fused precise single-point positioning time service method as claimed in any one of claims 1 to 5, characterized in that the device comprises:

7. Receiver comprising a memory and a processor, the memory storing a computer program, characterized in that the processor implements the steps of the method according to any one of claims 1 to 5 when the computer program is executed.