CN115826018B

CN115826018B - Ambiguity fixing method, ambiguity fixing device, receiver and storage medium

Info

Publication number: CN115826018B
Application number: CN202310153393.9A
Authority: CN
Inventors: 栾忠正
Original assignee: Guangzhou Asensing Technology Co Ltd
Current assignee: Guangzhou Asensing Technology Co Ltd
Priority date: 2023-02-22
Filing date: 2023-02-22
Publication date: 2023-06-02
Anticipated expiration: 2043-02-22
Also published as: CN115826018A

Abstract

The application provides an ambiguity fixing method, an ambiguity fixing device, a receiver and a storage medium, and relates to the technical field of satellite navigation and positioning. Firstly, obtaining differential data of observation data of a positioning system satellite and a static communication satellite, wherein the observation data comprises pseudo-range, carrier phase observation values and Doppler observation values, and the differential data comprises precise orbit clock difference data, satellite end pseudo-range, phase hardware delay data and ionosphere and troposphere delay data on a satellite signal propagation path; recording data with half periodicity in the observed data, and determining phase ambiguity according to the observed data and the differential data; and fixing single-difference wide-lane floating ambiguity and single-difference narrow-lane floating ambiguity according to the phase ambiguity and the data with half periodicity. The ambiguity fixing method, the ambiguity fixing device, the receiver and the storage medium have the advantage of being capable of fixing phase ambiguities with half-cycle characteristics.

Description

Ambiguity fixing method, ambiguity fixing device, receiver and storage medium

Technical Field

The present disclosure relates to the field of satellite navigation positioning technologies, and in particular, to an ambiguity fixing method, an ambiguity fixing device, a receiver, and a storage medium.

Background

The rise of the autopilot field requires various high-precision core technical supports, wherein one of the most critical cores is a fusion positioning technology of vehicle-mounted integrated navigation. Global satellite positioning system (GlobalNavigation Satellite System, GNSS) satellite positioning technology is the preferred solution for autopilot navigation positioning because it is capable of providing absolute position coordinates of a vehicle.

Currently, the main schemes of GNSS positioning technology are real-time differential (RTK) positioning technology and precision single point positioning (precise pointpositioning, PPP) technology.

Both RTK and PPP techniques require resolution of unknown phase ambiguities and attempt to fix to integers in order to provide reliable high-precision centimeter-level positioning services. The ambiguity of the phase observations is theoretically an integer value, but the low-cost GNSS signal receiver often has half cycle slip of the phase observations in complex observation environments due to low hardware performance, i.e., the phase ambiguity often has a fractional value of 0.5 instead of 0.0.

The prior art is dedicated to fixing the ambiguity with integer characteristics, and the ambiguity with non-integer characteristics does not participate in the ambiguity fixing, so that the ambiguity fixing rate of a satellite positioning algorithm is greatly reduced, and the availability of GNSS positioning is reduced.

To sum up, the prior art has a problem that the phase ambiguity of the half Zhou Texing cannot be fixed.

Disclosure of Invention

The invention aims to provide an ambiguity fixing method, an ambiguity fixing device, a receiver and a storage medium, which are used for solving the problem that the phase ambiguity of half Zhou Texing cannot be fixed in the prior art.

In order to achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:

in a first aspect, an embodiment of the present application provides an ambiguity fixing method, applied to a receiver, where the method includes:

obtaining differential data of observation data of a positioning system satellite and a static communication satellite, wherein the observation data comprises pseudo-range, carrier phase observation values and Doppler observation values, and the differential data comprises precision orbit clock difference data, satellite end pseudo-range, phase hardware delay data and ionosphere and troposphere delay data on a satellite signal propagation path;

recording data with half periodicity in the observed data, and determining phase ambiguity according to the observed data and the differential data;

and fixing single-difference wide lane floating point ambiguity and single-difference narrow lane floating point ambiguity according to the phase ambiguity and the data with half-cycle property.

In a second aspect, an embodiment of the present application provides an ambiguity fixing apparatus applied to a receiver, where the apparatus includes:

the signal receiving unit is used for obtaining differential data between the observation data of the positioning system satellite and the static communication satellite, wherein the observation data comprises pseudo-range, carrier phase observation value and Doppler observation value, and the differential data comprises precision orbit clock difference data, satellite end pseudo-range, phase hardware delay data and ionosphere and troposphere delay data on a satellite signal propagation path;

the signal processing unit is used for recording data with half-cycle property in the observed data and determining phase ambiguity according to the observed data and the differential data;

and the signal processing unit is also used for fixing the single-difference wide-lane floating ambiguity and the single-difference narrow-lane floating ambiguity according to the phase ambiguity and the data with half-cycle property.

In a third aspect, embodiments of the present application provide a receiver comprising a memory for storing one or more programs; and a processor, wherein the one or more programs, when executed by the processor, implement the ambiguity fixing method described above.

In a fourth aspect, embodiments of the present application provide a computer readable storage medium having stored thereon a computer program which, when executed by a processor, implements the ambiguity fixing method described above.

Compared with the prior art, the application has the following beneficial effects:

the application provides a ambiguity fixing method, a ambiguity fixing device, a receiver and a storage medium, wherein differential data of observation data of a positioning system satellite and static communication satellites are firstly obtained, the observation data comprise pseudo-range, carrier phase observation values and Doppler observation values, and the differential data comprise precise orbit clock difference data, satellite end pseudo-range, phase hardware delay data and ionosphere and troposphere delay data on a satellite signal propagation path; recording data with half periodicity in the observed data, and determining phase ambiguity according to the observed data and the differential data; and fixing single-difference wide-lane floating ambiguity and single-difference narrow-lane floating ambiguity according to the phase ambiguity and the data with half periodicity. In the method, after the related data are acquired, the data with half-cycle property in the observed data are marked, and when the single-difference wide-lane floating ambiguity fixing and the single-difference narrow-lane floating ambiguity fixing are carried out, the data with half-cycle property are fixed, so that the phase ambiguity fixing of half-cycle property can be realized.

In order to make the above objects, features and advantages of the present application more comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered limiting in scope, and that other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is an interaction schematic diagram of a receiver and a plurality of satellites for traffic according to an embodiment of the present application.

Fig. 2 is a schematic block diagram of a receiver according to an embodiment of the present application.

Fig. 3 is an exemplary flowchart of an ambiguity fixing method according to an embodiment of the present application.

Fig. 4 is an exemplary flowchart of the substep of S106 in fig. 3 provided in an embodiment of the present application.

Fig. 5 is a schematic block diagram of an ambiguity fixing apparatus according to an embodiment of the present application.

In the figure: a 100-receiver; a 101-processor; 102-memory; 103-a communication interface; 200-ambiguity fixing means; 210-a signal receiving unit; 220-a signal processing unit.

Detailed Description

For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. The components of the embodiments of the present application, which are generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present application, as provided in the accompanying drawings, is not intended to limit the scope of the application, as claimed, but is merely representative of selected embodiments of the application. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments herein without making any inventive effort, are intended to be within the scope of the present application.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures. Meanwhile, in the description of the present application, the terms "first", "second", and the like are used only to distinguish the description, and are not to be construed as indicating or implying relative importance.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

Some embodiments of the present application are described in detail below with reference to the accompanying drawings. The following embodiments and features of the embodiments may be combined with each other without conflict.

As described in the background, the main solutions of the present GNSS positioning technology are real-time differential (RTK) positioning technology and precision single point positioning (precise pointpositioning, PPP) technology. The RTK technology has high convergence rate and high positioning precision, and is a satellite positioning technology commonly adopted in the field of high-precision positioning. The basic principle of the RTK technology is that a reference station positioned in the vicinity of a vehicle is used for sending station coordinates of the reference station, a pseudo-range carrier phase observation value and other difference data to a vehicle terminal through a network, and a vehicle terminal algorithm utilizes satellite observation data acquired by the vehicle terminal to conduct difference processing with the received difference data, so that related errors are eliminated or weakened, and real-time centimeter-level positioning information is obtained.

With the development of RTK technology, network RTK technology gradually replaces RTK technology, and the basic principle of network RTK technology is that a plurality of reference stations with the distance of about 70 km between stations near a vehicle user are utilized to conduct data modeling, virtual reference station differential data are generated, and the virtual reference station differential data are sent to an end user through a network to conduct differential positioning.

The PPP technology does not need a reference station, only needs a receiver of a vehicle terminal, receives data such as precise satellite orbit clock error and the like, and can obtain centimeter-level high-precision positioning information through an error modeling and error parameterization processing method. However, because of the slow convergence rate of PPP technology, it usually takes 20-30 minutes to obtain centimeter-level positioning information after continuous observation.

With the development of technology, the atmospheric delay error information of the GNSS satellite signal is increased on the basis of the PPP technology, the enhanced PPP technology appears, and the enhanced PPP technology integrates all the advantages of the PPP technology and can provide centimeter-level positioning service in real time within tens of seconds.

The GNSS satellite observation data mainly comprises two kinds of observation values of pseudo-range and carrier phase, the precision of the pseudo-range observation value is in the order of decimeters to meters, and the precision of the phase observation value can reach the millimeter level. The phase observations contain unknown integer ambiguities and need to be resolved as unknowns. In theory, the phase ambiguity has integer characteristics, when the ambiguity is successfully fixed into an integer during data understanding, the technical field of GNSS positioning refers to the coordinate solution as a fixed solution, otherwise, referred to as a floating solution. The coordinate precision of the fixed solution result position can reach the centimeter level, and the coordinate precision of the floating solution result is decimeter to meter level.

Objective drawbacks of the prior art:

both RTK and PPP techniques require resolution of unknown phase ambiguities and attempt to fix to integers in order to provide reliable high-precision centimeter-level positioning services. The fixed solution has reliable precision and high precision which is better than 10 cm; the floating point solution accuracy is unreliable, varying from decimeter to meter. The ambiguity of the phase observations is theoretically an integer value, but the low-cost GNSS signal receiver often has half cycle slip of the phase observations in complex observation environments due to low hardware performance, i.e., the phase ambiguity often has a fractional value of 0.5 instead of 0.0. Particularly in the field of automatic driving, vehicle manufacturing is very cost-sensitive, and high-precision navigation and positioning devices all use low-cost consumer-grade GNSS signal receivers.

Accordingly, to overcome the above-mentioned drawbacks of the prior art, the present invention provides a GNSS phase ambiguity fixing method, which can fix not only ambiguities with integer characteristics but also phase ambiguities with half-cycle characteristics.

In view of this, the application provides a method for fixing ambiguity, which realizes the effect of fixing the phase ambiguity of the half-cycle characteristic by combining half-cycle data to fix the single-difference wide lane floating ambiguity and the single-difference narrow lane floating ambiguity.

It should be noted that, the ambiguity fixing method provided in the present application may be applied to a receiver, where the receiver may be mounted on an automobile to further realize navigation in the running process of the automobile, and certainly, may also be mounted on other devices to further realize navigation, which is not limited herein. Referring to fig. 1, the receiver may communicate with a plurality of satellites to further receive satellite data. The plurality of satellites may include a positioning system satellite and a stationary communication satellite, where the positioning system satellite is a GNSS navigation satellite, and in one implementation manner, the GNSS navigation satellite includes a GPS satellite navigation system, a Galileo satellite navigation system, and a BDS beidou satellite navigation system, that is, in fig. 1, the positioning system satellite 1 may be a GPS satellite, the positioning system satellite 2 may be a Galileo satellite, and the positioning system satellite 3 may be a BDS beidou satellite. On the basis, the receiver can receive the observation data of the GPS satellite, the Galileo satellite and the BDS Beidou satellite, simultaneously receive the differential data of the static communication satellite, and utilize terminal algorithm software to calculate the received data, and can obtain centimeter-level positioning information without referring to the data of the station.

As an implementation manner, a schematic block diagram of a receiver 100 provided in an embodiment of the present application is shown in fig. 2, where the receiver 100 includes a memory 102, a processor 101, and a communication interface 103, where the memory 102, the processor 101, and the communication interface 103 are directly or indirectly electrically connected to each other to implement data transmission or interaction. For example, the components may be electrically connected to each other via one or more communication buses or signal lines.

The memory 102 may be used for storing software programs and modules, such as program instructions or modules corresponding to the ambiguity fixing apparatus provided in the embodiments of the present application, and the processor 101 executes the software programs and modules stored in the memory 102, thereby executing various functional applications and data processing, and further executing the steps of the ambiguity fixing method provided in the embodiments of the present application. The communication interface 103 may be used for communication of signaling or data with other node devices.

The Memory 102 may be, but is not limited to, random access Memory (Random Access Memory, RAM), read Only Memory (ROM), programmable Read Only Memory (Programmable Read-OnlyMemory, PROM), erasable Read Only Memory (Erasable ProgrammableRead-Only Memory, EPROM), electrically erasable programmable Read Only Memory (Electric Erasable Programmable Read-Only Memory, EEPROM), etc.

The processor 101 may be an integrated circuit chip with signal processing capabilities. The processor 101 may be a general-purpose processor including a central processing unit (Central Processing Unit, CPU), a network processor (Network Processor, NP), etc.; but also digital signal processors (Digital Signal Processing, DSP), application specific integrated circuits (Application SpecificIntegrated Circuit, ASIC), field programmable gate arrays (Field-ProgrammableGate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

It will be appreciated that the configuration shown in fig. 2 is merely illustrative, and that receiver 100 may also include more or fewer components than shown in fig. 2, or have a different configuration than shown in fig. 2. The components shown in fig. 2 may be implemented in hardware, software, or a combination thereof.

The ambiguity fixing method provided in the embodiment of the present application is described below with the receiver 100 as a schematic implementation body.

As an implementation, referring to fig. 3, the ambiguity fixing method includes:

s102, obtaining differential data of observation data of a positioning system satellite and a static communication satellite, wherein the observation data comprises pseudo-range, carrier phase observation values and Doppler observation values, and the differential data comprises precise orbit clock difference data, satellite end pseudo-range, phase hardware delay data and ionosphere and troposphere delay data on a satellite signal propagation path.

And S104, recording data with half-cycle property in the observed data, and determining the phase ambiguity according to the observed data and the differential data.

S106, fixing single-difference wide-lane floating point ambiguity and single-difference narrow-lane floating point ambiguity according to the phase ambiguity and the data with half-cycle property.

In this application, the receiver first acquires differential data between GNSS navigation satellite signal data (i.e. observation data) and a stationary communication satellite, where the observation data includes pseudorange and carrier phase observations and doppler observations, and the differential data of the stationary communication satellite includes precise orbital clock difference data, satellite end pseudorange and phase hardware delay data, and ionosphere and troposphere delay data on a satellite signal propagation path. Also, the differential data of the stationary communication satellite may be provided by the service provider, i.e. the differential data of the stationary communication satellite may be regarded as known data.

After the observation data is acquired, the data with half-cycle characteristics can be determined, in one implementation, the observation data LLI can be marked and detected, LLI (Loss of Lock Indicator) represents an out-of-lock identifier, which ranges from 0 to 7 and is converted into a binary format of 000-111, i.e. 3 bits. Where bit 0 and bit 1 are used only for phase. The data with the second bit of the data LLI being 1 is recorded for the subsequent ambiguity fixing step, wherein the marked data represents that the phase ambiguity has a half-cycle characteristic, and the identification and recording of the data with half-cycle characteristic is realized in this way.

After data processing, phase ambiguity is determined according to observed data and the differential data, and then single-difference wide-lane floating ambiguity fixing and single-difference narrow-lane floating ambiguity fixing are performed by combining half-period data.

As an implementation manner, when determining the phase ambiguity, the phase ambiguity may be determined by solving by constructing an observation equation, where the observation equation provided in the present application is a non-combined PPP observation equation, and the equation is:

wherein (1)>

and />

Pseudo-range and phase observations of j frequencies of satellite S, j=1 or 2, respectively; />

The geometrical distance between the phase center of the r antenna of the receiver and the s phase center of the satellite is used; c is the speed of light in vacuum; />

Receiver clock differences for j frequencies of receiver r, and the clock differences at each frequency are different; />

Clock difference for satellite s; t is wet tropospheric delay, +.>

Ionospheric delay at frequency j; />

Is the square ratio of the frequency->

，/>

Frequency value of frequency j +.>

A frequency value of frequency j=1; />

And

pseudo-range hardware delay for receiver and satellite side, respectively,/->

and />

Phase hardware delays at the receiver and satellite ends, respectively; />

and />

Wavelength and phase ambiguity of j frequency of satellite s, respectively, +.>

and />

Observation noise for the pseudorange and the phase observations, respectively; />

and />

Ionospheric delay data and tropospheric delay data, respectively,>

and />

The accuracy errors of the ionosphere and troposphere differential data, respectively.

In this observation equation, the unknown parameters are receiver clock difference, ionospheric delay at the first frequency, and phase ambiguity at each frequency. The hardware delay at the receiver is absorbed by the receiver clock error, and the orbit error and clock error at the satellite end and the hardware delay at the satellite end can be corrected by the received differential data. Errors such as tropospheric dry delay, phase wrapping, antenna phase center offset, relativistic effects, etc. can be corrected by the model and are not described in detail herein.

It should be noted that, the present application adopts the enhanced precision single-point positioning technology to enhance the delay data precision of the wet troposphere and the ionosphere, that is, utilizes the acquired ionosphere and troposphere delay data on the satellite signal propagation path, combines the observation noise to determine the final delay data, and can achieve the purpose of enhancing the data precision.

As an implementation manner, referring to fig. 4, the step of fixing the single-difference wide-lane floating ambiguity according to the phase ambiguity and the data with half-cycle property includes:

s1061, determining single-difference wide-lane floating ambiguity between stars according to the phase ambiguity of the moving star and the reference star and the data with half-cycle property; the reference satellite is the satellite with the highest altitude angle in the positioning system satellites, and the moving satellite is the positioning system satellite except the reference satellite;

s1062, determining a first variance-covariance matrix according to the inter-satellite single-difference wide-lane floating ambiguity;

s1063, fixing the single-difference wide-lane floating ambiguity according to the first variance-covariance matrix.

The single-difference wide-lane floating ambiguity between stars satisfies the formula:

wherein ,N_x，y Is the phase ambiguity of the first and second frequencies of the moving and reference satellites, respectively, where the first and second frequencies are the frequencies at f=1 and f=2, respectively.

Is half cycle ambiguity; and with data that is half-period in nature,

0.5, without half-cycle data, +.>

0.0. Since the data having half-cycle property has been recorded in S102, it is possible to define +.>

0.5.

With this implementation, for data with half-cycle properties, a 0.5-week offset can be added so that its phase ambiguity is an integer; and for ambiguities with integer characteristics, due to

0.0, so that no cycle bias is added, the integer property is still maintained, and all data is converted into the integer property.

After determining the inter-star single-difference wide-lane floating ambiguity, a corresponding first variance-covariance matrix may be determined, the first variance-covariance matrix satisfying the formula:

wherein ,

is a single-difference wide-lane floating ambiguity vector, < >>

For the first and second frequency floating ambiguity vectors, Q is/>

Corresponding variance-covariance matrix, +.>

For the conversion matrix of the ambiguity to single-difference wide-lane floating ambiguity, T represents the transpose of the matrix,/->

Is->

Vector of->

Is a first variance-covariance matrix. And then fixing the single-difference wide-lane floating ambiguity according to the first variance-covariance matrix.

The step of fixing the single-difference wide-lane floating point ambiguity comprises the following steps:

s1, judging whether the number of single-difference wide-lane floating ambiguity is larger than a threshold value, if not, executing S2, and if so, executing S3.

S2, judging that the ambiguity fixing fails.

And S3, determining the integer candidate subset and the candidate subset quality index of the floating ambiguity.

And S4, carrying out weighted average on the integer candidate subsets according to the candidate subset quality index.

S5, judging whether the decimal part of all the satellite ambiguity values after weighted averaging is smaller than a set value, if so, executing S6, and if not, returning to executing S1 until the decimal part of all the satellite ambiguity values after weighted averaging is smaller than the set value.

S6, recovering the half cycle characteristic ambiguity.

The number of the threshold values set in the present application may be 4 or 5, which is not limited herein. If the number of the single-difference wide-lane floating point ambiguities is larger than the threshold value, continuing to execute the subsequent steps, otherwise, judging that the ambiguity fixing fails, and ending the ambiguity fixing flow.

As one implementation, in determining integer candidate subsets and candidate subset quality metrics for floating ambiguity, a lambda search method may be employed to obtain integer candidate subsets for floating ambiguity

Corresponding candidate subset quality index +.>

. As another implementation, the candidate subset quality indicator +.>

It can also be determined by the formula:

is a quality indicator of candidate subset i, +.>

Is a single difference wide lane floating ambiguity vector, < ->

Is an integer ambiguity value vector of candidate subset i, +.>

Is the inverse of the floating ambiguity variance-covariance matrix. The lambda search method is adopted to search that the total number n of candidate subsets is 30 groups.

When weighted average is performed on integer candidate subsets, the weight of each candidate subset can be calculated according to the quality index of the candidate subset, and the weight satisfies the formula:

wherein ,

is the weight of candidate subset i, n is the number of candidate subsets, +.>

Is a quality indicator of candidate subset i. And then carrying out weighted average according to the weight of each candidate subset, the single-difference wide-lane floating ambiguity vector and the integer ambiguity value vector of the candidate subset i to determine a floating ambiguity fixed result value vector.

The floating ambiguity fixed result value vector satisfies the formula:

wherein ,

is a floating ambiguity fixed result value vector, n is the number of candidate subsets, +.>

Is a single difference wide lane floating ambiguity vector, < ->

Is an integer ambiguity value vector of candidate subset i, +.>

Is the weight of candidate subset i.

Then, if the fractional part of all satellite ambiguity values of the weighted average result is less than 0.01, the candidate subset weighted average result is successfully fixed, otherwise the fixing fails. If the fixation is successful, half-cycle characteristic ambiguity recovery is required, since half-cycle characteristic ambiguity is added in step S1061

Is thus the integer ambiguity of the weighted average result needs to be subtracted +.>

. Floating ambiguity fix result is +.>

The formula is satisfied:

if the fixing fails, eliminating the floating ambiguity with the lowest satellite altitude angle from all the floating ambiguities, and repeatedly executing the steps of determining the integer candidate subset and the candidate subset quality index of the floating ambiguity until the decimal part of all the satellite ambiguity values after weighted averaging is smaller than a set value.

After the single-difference wide-lane floating point ambiguity fixing is completed, the single-difference narrow-lane floating point ambiguity is continuously fixed in a similar manner to the single-difference wide-lane floating point ambiguity fixing. Firstly, determining single-difference narrow lane floating ambiguity between stars according to phase ambiguity between a moving star and a reference star and data with half-cycle property; the reference star is the satellite with the highest altitude angle in the positioning system satellites, the moving star is the positioning system satellite except the reference star, then a second variance-covariance matrix is determined according to the inter-satellite single-difference narrow-lane floating ambiguity, and the single-difference narrow-lane floating ambiguity is fixed according to the second variance-covariance matrix.

Wherein, the single-difference narrow lane floating ambiguity between stars satisfies the formula:

wherein ,

phase floating ambiguity of first frequency of mobile star and reference star, respectively, +.>

Is half-cycle ambiguity and has half-cycle data +.>

0.5, without half-cycle data, +.>

0.0.

The second variance-covariance matrix satisfies the formula:

wherein ,

and->

A single-difference narrow-lane floating ambiguity vector and a corresponding second variance-covariance matrix, respectively +.>

For the first frequency floating ambiguity vector, +.>

Is->

Corresponding variance-covariance matrix, +.>

For the conversion matrix of the ambiguity to single-difference narrow lane floating ambiguity, T represents the transpose of the matrix,/->

Is->

Is a vector of (a).

The method for fixing the single-difference narrow-lane floating ambiguity according to the second variance-covariance matrix is the same as the method for fixing the single-difference wide-lane floating ambiguity, and will not be described here.

In conclusion, the correction and integer fixing of the half-cycle characteristic ambiguity are added, the half-cycle characteristic ambiguity after the integer fixing is recovered, and the ambiguity fixing rate can be improved. Not only the ambiguity with integer characteristics but also the phase ambiguity with half-cycle characteristics can be fixed.

Based on the above implementation, referring to fig. 5, the present application further provides an ambiguity fixing apparatus 200, applied to a receiver, where the apparatus includes:

the signal receiving unit 210 is configured to obtain differential data between observation data of a positioning system satellite and a stationary communication satellite, where the observation data includes a pseudo-range, a carrier phase observation value, and a doppler observation value, and the differential data includes precise orbit clock difference data, a satellite-end pseudo-range, phase hardware delay data, and ionosphere and troposphere delay data on a satellite signal propagation path.

It is understood that S102 may be performed by the signal receiving unit 210.

The signal processing unit 220 is configured to record data with half-periodicity in the observed data, and determine the phase ambiguity according to the observed data and the differential data.

It is understood that S104 may be performed by the signal processing unit 220.

The signal processing unit 220 is further configured to perform single-difference wide-lane floating ambiguity fixing and single-difference narrow-lane floating ambiguity fixing according to the phase ambiguity and the data with half-cycle property.

It is understood that S106 may be performed by the signal processing unit 220.

In summary, the present application provides a method, an apparatus, a receiver, and a storage medium for fixing ambiguity, where first differential data between observed data of a positioning system satellite and stationary communication satellite is obtained, where the observed data includes pseudo-range, carrier phase observed values, and doppler observed values, and the differential data includes precise orbit clock difference data, satellite end pseudo-range, phase hardware delay data, and ionosphere and troposphere delay data on a satellite signal propagation path; recording data with half periodicity in the observed data, and determining phase ambiguity according to the observed data and the differential data; and fixing single-difference wide-lane floating ambiguity and single-difference narrow-lane floating ambiguity according to the phase ambiguity and the data with half periodicity. In the method, after the related data are acquired, the data with half-cycle property in the observed data are marked, and when the single-difference wide-lane floating ambiguity fixing and the single-difference narrow-lane floating ambiguity fixing are carried out, the data with half-cycle property are fixed, so that the phase ambiguity fixing of half-cycle property can be realized.

In the embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other manners as well. The apparatus embodiments described above are merely illustrative, for example, of the flowcharts and block diagrams in the figures that illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods and computer program products according to embodiments of the present application. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s).

It should also be noted that in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved.

It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

In addition, the functional modules in the embodiments of the present application may be integrated together to form a single part, or each module may exist alone, or two or more modules may be integrated to form a single part.

The functions, if implemented in the form of software functional modules and sold or used as a stand-alone product, may be stored in a computer-readable storage medium. Based on such understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a U disk, a mobile hard disk, a read-only memory, a random access memory, a magnetic disk or an optical disk.

Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention, and the scope of the invention should be assessed accordingly to that of the appended claims.

Claims

1. A method of ambiguity fixing, for use in a receiver, the method comprising:

according to the phase ambiguity and the data with half-cycle property, single-difference wide lane floating ambiguity fixing and single-difference narrow lane floating ambiguity fixing are carried out;

the step of fixing the single-difference wide-lane floating ambiguity according to the phase ambiguity and the data with half-cycle property comprises the following steps:

determining single-difference wide-lane floating ambiguity between stars according to the phase ambiguity between the moving star and the reference star and the data with half-cycle property; the reference satellite is the satellite with the highest altitude angle in the positioning system satellites, and the moving satellite is a positioning system satellite except the reference satellite;

determining a first variance-covariance matrix according to the inter-satellite single-difference wide-lane floating ambiguity;

when the number of the single-difference wide-lane floating point ambiguities is larger than a threshold value, determining an integer candidate subset and a candidate subset quality index of the floating point ambiguities;

carrying out weighted average on the integer candidate subset according to the candidate subset quality index;

when the decimal part of all satellite ambiguity values after weighted averaging is smaller than a set value, recovering half-period characteristic ambiguity;

and when the decimal part of any satellite ambiguity value after weighted averaging is larger than or equal to a set value, eliminating floating ambiguity with the lowest satellite altitude angle, and repeatedly executing the steps of determining the integer candidate subset and the candidate subset quality index of the floating ambiguity until the decimal part of all satellite ambiguity values after weighted averaging is smaller than the set value.

2. The ambiguity fixing method of claim 1, wherein the step of determining a phase ambiguity from the observed data, the differential data, comprises:

constructing an observation equation and solving to determine phase ambiguity; the observation equation is:

wherein ,

and />

Pseudo-range and phase observations of the j frequency of satellite S, respectively; />

Clock difference for satellite s; trop is wet tropospheric delay, +.>

Ionospheric delay at frequency j; />

Is the square ratio of the frequency->

，/>

Frequency value of frequency j +.>

A frequency value of frequency j=1; />

and />

Pseudo-range hardware delay for receiver and satellite side, respectively,/->

and />

Phase hardware delays at the receiver and satellite ends, respectively; />

and />

Wavelength and phase ambiguity of j frequency of satellite s, respectively, +.>

and />

and />

Ionospheric delay data and tropospheric delay data, respectively,>

and />

3. The ambiguity fixing method of claim 1, wherein the inter-satellite single-difference wide-lane floating ambiguity satisfies the formula:

wherein ,N_x，y For phase ambiguities at the first and second frequencies of the moving and reference satellites respectively,

is half cycle ambiguity; and with half-cycle data, +.>

0.5, without half-cycle data, +.>

0.0.

4. The ambiguity fixing method of claim 3, wherein the first variance-covariance matrix satisfies the formula:

wherein ,

is a single-difference wide-lane floating ambiguity vector, < >>

For the first and second frequency floating ambiguity vectors, Q is

Corresponding variance-covariance matrix, +.>

Is->

Vector of->

Is a first variance-covariance matrix.

5. The ambiguity fixing method of claim 1, wherein the candidate subset quality indicator satisfies the formula:

wherein ,

is a quality indicator of candidate subset i, +.>

Is a single difference wide lane floating ambiguity vector, < ->

Is an integer ambiguity value vector of candidate subset i, +.>

Is the inverse of the floating ambiguity variance-covariance matrix.

6. The method of claim 1, wherein the step of weighted averaging the integer candidate subset according to the candidate subset quality indicator comprises:

calculating the weight of each candidate subset according to the candidate subset quality index, wherein the weight satisfies the formula:

wherein ,

is the weight of candidate subset i, n is the number of candidate subsets, +.>

Is a quality indicator of candidate subset i;

and carrying out weighted average according to the weight of each candidate subset, the single-difference wide-lane floating ambiguity vector and the integer ambiguity value vector of the candidate subset i to determine a floating ambiguity fixed result value vector.

7. The ambiguity fixing method of claim 6, wherein the floating ambiguity fix result value vector satisfies the formula:

wherein ,/>

Is a floating ambiguity fixed result value vector, n is the number of candidate subsets,

single-difference wide-lane floating ambiguity vector, +.>

Is an integer ambiguity value vector of candidate subset i, +.>

Is the weight of candidate subset i.

8. The ambiguity fixing method of claim 1, wherein the step of single-bad lane floating ambiguity fixing based on the phase ambiguity and the data having half-cycle characteristics comprises:

determining single-difference narrow-lane floating ambiguity between stars according to the phase ambiguity between the moving star and the reference star and the data with half-cycle property; the reference satellite is the satellite with the highest altitude angle in the positioning system satellites, and the moving satellite is a positioning system satellite except the reference satellite;

determining a second variance-covariance matrix according to the inter-satellite single-difference narrow-lane floating ambiguity;

and fixing the single-difference narrow lane floating ambiguity according to the second variance-covariance matrix.

9. The ambiguity fixing method of claim 8, wherein the inter-satellite single-difference narrow-lane floating ambiguity satisfies the formula:

wherein ,

Is half-cycle ambiguity and has half-cycle data +.>

0.5, without half-cycle data, +.>

0.0.

10. The ambiguity fixing method of claim 9, wherein the second variance-covariance matrix satisfies the formula:

wherein ,

and->

For the first frequency floating ambiguity vector, +.>

Is->

Corresponding variance-covariance matrix, +.>

Is->

Is a vector of (a).

11. An ambiguity fixing apparatus for use in a receiver, said apparatus comprising:

the signal processing unit is also used for fixing single-difference wide-lane floating ambiguity and single-difference narrow-lane floating ambiguity according to the phase ambiguity and the data with half-cycle property;

the signal processing unit is specifically configured to:

12. A receiver, comprising: a memory for storing one or more programs;

a processor;

the method of any of claims 1-10 is implemented when the one or more programs are executed by the processor.

13. A computer readable storage medium, on which a computer program is stored, which computer program, when being executed by a processor, implements the method according to any of claims 1-10.