CN116338739A

CN116338739A - Calibration method, device, receiver and storage medium for GLONASS system pseudo-range observed quantity

Info

Publication number: CN116338739A
Application number: CN202310371501.XA
Authority: CN
Inventors: 陈孔哲; 周光宇; 孙峰; 刘志龙; 胡盼圆
Original assignee: Unicore Communications Inc
Current assignee: Unicore Communications Inc
Priority date: 2023-04-07
Filing date: 2023-04-07
Publication date: 2023-06-27

Abstract

The embodiment of the disclosure provides a calibration method, a device, a receiver and a storage medium for a GLONASS system pseudo-range observed quantity, wherein the calibration method for the GLONASS system pseudo-range observed quantity comprises the following steps: acquiring frequency points and channel numbers of original pseudo-range observables; determining inter-frequency code deviation corresponding to the frequency point and the channel number of the original pseudo-range observed quantity; and calibrating the original pseudo-range observed quantity according to the determined inter-frequency code deviation, and outputting the calibrated pseudo-range observed quantity. According to the method and the device, the original pseudo-range observed quantity is calibrated according to the prestored inter-frequency code deviation corresponding to each frequency point and the channel number, so that the inter-frequency code deviation of GLONASS of all receivers in a reference station network is consistent, the inter-frequency code deviation of GLONASS of receivers of any brand is also consistent, and further the positioning accuracy of network RTK or PPP service is improved.

Description

Calibration method, device, receiver and storage medium for GLONASS system pseudo-range observed quantity

Technical Field

The embodiments of the present disclosure relate to the field of satellite navigation technologies, but are not limited to, and in particular, to a calibration method, device, receiver and storage medium for a pseudorange observation of a GLONASS system.

Background

The global satellite navigation system (Global Navigation Satellite System, GNSS) is a satellite system with a plurality of satellites that can transmit signals containing position and time information to a terrestrial GNSS receiver, by means of which the receiver can achieve a position fix. Currently, the main GNSS systems are the european union Galileo (Galileo) satellite navigation system, the american global positioning system (Global Positioning System, GPS), the russian GLONASS (GLONASS) satellite navigation system, the chinese beidou navigation system, and the japanese Quasi-zenith satellite system (Quasi-Zenith Satellite System, QZSS). The satellite navigation system has high positioning precision and covers the whole world, and is widely applied to a plurality of fields such as navigation, measurement and mapping, fine agriculture, intelligent robots, unmanned aerial vehicles and the like.

While applications such as surveying and mapping, fine agriculture, intelligent robots, intelligent driving and unmanned aerial vehicles often require positioning services with centimeter-level precision, technologies capable of providing centimeter-level satellite positioning services mainly include Real-Time Kinematic (RTK) and precision single point positioning (Precise Point Positioning, PPP) technologies. RTK technology is a high-precision satellite positioning technology that is currently widely used. The RTK technology needs the support of a base station, and the mobile station eliminates or weakens errors such as satellite orbit, satellite clock error, ionosphere, troposphere and the like through the observed quantity of the base station by utilizing the error correlation between measuring stations, so that the centimeter-level positioning precision is achieved. The satellite clock difference is irrelevant to the distance between the measuring stations and can be completely eliminated; the satellite orbit, ionosphere and troposphere errors are related to the distance between the stations, the closer the distance between the base station mobile stations is, the stronger the error correlation is, the smaller the residual error is after the single difference between the mobile stations and the base station is observed, and the longer the distance is, the weaker the correlation is. After the distance between the base station and the mobile station exceeds a certain distance, such as 30 km, the atmosphere residual error can reach the decimeter level, and double-difference ambiguity is difficult to fix, so that centimeter-level positioning cannot be realized. In order to meet the requirements of large-scale high-precision applications such as fine agriculture, intelligent driving, unmanned aerial vehicles and the like, a plurality of base stations are generally required to be established to form a network, and services are provided for clients in a network RTK mode. The PPP technique eliminates satellite orbit and clock error in broadcast ephemeris by precise satellite orbit and clock error data. Ionospheric errors are eliminated by multi-frequency combining and tropospheric errors can be estimated by parameters. Some sophisticated single point location services also broadcast ionosphere, troposphere data that can also be used to attenuate ionosphere and troposphere errors. The precise satellite orbit and clock error also need a base station network distributed in the whole country and even the whole world to acquire the tracking data of each base station to the satellite, and the known base station position is used for solving the precise coordinate and clock error of the satellite, namely the precise orbit and clock error and the atmospheric parameters. Precision tracks and clock errors are often broadcast to users in the form of broadcast ephemeris corrections to save bandwidth.

The network RTK needs the user to report the outline position of the user, and the server can send the base station data based on the user position. The accurate data of PPP is suitable for all users, and thus can be transmitted to the users in the form of satellite broadcast. In the network RTK service range, the availability and precision of the network RTK are often better than those of PPP, and the PPP service does not need the user to report the position, and the coverage range is wider. The network RTK and PPP may be complementary providing higher availability to the user.

Whether it be network RTK services or PPP services that provide PPP precision data for users, it is necessary to establish a base station network. The current base stations are all system-wide receivers. In order to distinguish between signals transmitted by different satellites, GNSS navigation systems require the use of multiple access mechanisms. The navigation signals of GPS, BDS, galileo, QZSS systems all employ a code division multiplexing (Code division multiplexing access, CDMA) mechanism, while the GLONASS navigation signals employ a frequency division multiplexing (Frequency Division Multiple Access, FDMA) mechanism. Thus, the frequencies of the plurality of GLONASS satellite signals received by the receiver may be different. Signals of different frequencies at the same Frequency point may generate Inter-Frequency Bias (IFB) in the receiver observation. The inter-frequency offset is mainly due to the hardware delay difference of the signals of different frequencies in the receiver. There is an inter-frequency bias, whether pseudorange or carrier observations. Inter-Frequency Bias for pseudorange observations is commonly referred to as Inter-Frequency Code Bias (IFCB). The Inter-Frequency offset for the observed quantity of the carrier is generally referred to as Inter-Frequency-Phase-Bias (IFPB). Both IFCB and IFPB affect the positioning of PPP and RTK in which GLONASS participates, and also affect network RTK resolution and PPP precision orbit clock resolution. The main approach currently adopted is mainly to estimate the difference in frequency offset between different brands of receivers when the RTK is resolved. Some students estimate the GLONASS inter-frequency code bias of multiple brand-received ionosphere combinations by PPP method through pre-collected data for later data calculation. However, even with the same brand of receiver, the inter-frequency code bias between the receivers is not the same because of the differences in hardware or software. Even in the same batch of receivers, the difference in the code bias between frequencies is caused by the difference in the consistency of the hardware components.

Disclosure of Invention

The embodiment of the disclosure provides a calibration method, a device, a receiver and a storage medium for a GLONASS system pseudo-range observed quantity, and through calibration, the GLONASS frequency code bias of all receivers in a reference station network can be consistent, and the GLONASS frequency code bias of receivers of the same brand can also be consistent.

The embodiment of the disclosure provides a calibration method for a GLONASS system pseudo-range observed quantity, comprising the following steps:

acquiring frequency points and channel numbers of original pseudo-range observables;

determining inter-frequency code deviation corresponding to the frequency point and the channel number of the original pseudo-range observed quantity;

and calibrating the original pseudo-range observed quantity according to the determined inter-frequency code deviation, and outputting the calibrated pseudo-range observed quantity.

The embodiment of the disclosure also provides a calibration device for the GLONASS system pseudo-range observed quantity, which comprises a memory; and a processor coupled to the memory, the memory for storing instructions, the processor configured to perform the steps of the method of calibrating pseudorange observations of the GLONASS system according to any of the embodiments of the present disclosure based on the instructions stored in the memory.

The embodiment of the disclosure also provides a receiver of the GLONASS system, which comprises a calibration device of the GLONASS system pseudo-range observed quantity according to any embodiment of the disclosure.

The embodiments of the present disclosure also provide a storage medium having stored thereon a computer program which, when executed by a processor, implements a method for calibrating pseudorange observations of a GLONASS system according to any of the embodiments of the present disclosure.

According to the calibration method, the device, the receiver and the storage medium for the GLONASS system pseudo-range observed quantity, the original pseudo-range observed quantity is calibrated according to the pre-stored inter-frequency code deviation corresponding to each frequency point and the channel number, so that the GLONASS inter-frequency code deviation of all receivers in a reference station network is consistent, the GLONASS inter-frequency code deviation of any brand of receivers is consistent, and the positioning accuracy of network RTK or PPP service is improved.

Additional features and advantages of the disclosure will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the disclosure. Other advantages of the present disclosure may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

The accompanying drawings are included to provide an understanding of the technical aspects of the present disclosure, and are incorporated in and constitute a part of this specification, illustrate the technical aspects of the present disclosure and together with the embodiments of the disclosure, not to limit the technical aspects of the present disclosure.

FIG. 1 is a flow chart of a method for calibrating a pseudorange observation of a GLONASS system in accordance with an embodiment of the disclosure;

fig. 2 is a schematic structural diagram of a calibration device for pseudorange observables of a GLONASS system according to an embodiment of the disclosure.

Detailed Description

The present disclosure describes several embodiments, but the description is illustrative and not limiting, and it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of the embodiments described in the present disclosure. Although many possible combinations of features are shown in the drawings and discussed in the detailed description, many other combinations of the disclosed features are possible. Any feature or element of any embodiment may be used in combination with or in place of any other feature or element of any other embodiment unless specifically limited.

The present disclosure includes and contemplates combinations of features and elements known to those of ordinary skill in the art. The embodiments, features and elements of the present disclosure that have been disclosed may also be combined with any conventional features or elements to form a unique inventive arrangement as defined by the claims. Any feature or element of any embodiment may also be combined with features or elements from other inventive arrangements to form another unique inventive arrangement as defined in the claims. Thus, it should be understood that any of the features shown and/or discussed in this disclosure may be implemented alone or in any suitable combination. Accordingly, the embodiments are not to be restricted except in light of the attached claims and their equivalents. Further, various modifications and changes may be made within the scope of the appended claims.

Furthermore, in describing representative embodiments, the specification may have presented the method and/or process as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. Other sequences of steps are possible as will be appreciated by those of ordinary skill in the art. Accordingly, the particular order of the steps set forth in the specification should not be construed as limitations on the claims. Furthermore, the claims directed to the method and/or process should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the sequences may be varied and still remain within the spirit and scope of the embodiments of the present disclosure.

Whether it be network RTK services or PPP services that provide PPP precision data for users, it is necessary to establish a base station network. The consistency of the code bias among GLONASS frequencies of each base station in the whole network has important influence on the network RTK calculation and PPP precision orbit clock error calculation. If the code deviation among the GLONASS frequencies of each base station is consistent, the GLONASS ambiguity fixing speed can be greatly improved in network RTK calculation, and the availability of network RTK service is further improved; the accuracy of the GLONASS track and clock can be improved in the precision track clock calculation. In the current tracking station networking, the consistency of the code deviation among the base stations in the network is improved mainly by adopting the same brand receiver. However, even receivers of the same brand and same batch may have different frequency code bias due to the existence of consistency differences of hardware components.

As shown in fig. 1, an embodiment of the present disclosure provides a calibration method for a pseudorange observation of a GLONASS system, including:

step 101, obtaining frequency points and channel numbers of original pseudo-range observables;

102, determining inter-frequency code deviation corresponding to frequency points and channel numbers of original pseudo-range observables;

and 103, calibrating the original pseudo-range observed quantity according to the determined inter-frequency code deviation, and outputting the calibrated pseudo-range observed quantity.

According to the calibration method for the GLONASS system pseudo-range observed quantity, the original pseudo-range observed quantity is calibrated according to the pre-stored inter-frequency code deviation corresponding to each frequency point and channel number, so that the GLONASS inter-frequency code deviation of all receivers in a reference station network is consistent, the GLONASS inter-frequency code deviation of receivers of any brand is consistent, and further the positioning accuracy of network RTK or PPP service can be improved.

In some exemplary embodiments, before the step of determining the inter-frequency code bias corresponding to the frequency point and the channel number of the original pseudo-range observables, the calibration method further comprises:

determining the inter-frequency code deviation corresponding to each frequency point and channel number;

and storing the corresponding relation among each frequency point, the channel number and the inter-frequency code deviation.

In the embodiment of the disclosure, when storing the correspondence of each frequency point, the channel number and the inter-frequency code deviation, the determined correspondence of the frequency point, the channel number and the inter-frequency code deviation may be stored in a storage device of the receiver.

In some exemplary embodiments, the inter-frequency code bias corresponding to each frequency bin and channel number is determined by:

determining a reference receiver and a receiver to be calibrated;

acquiring original pseudo-range observed quantities of all channels when a reference receiver and a receiver to be calibrated are connected to the same antenna;

substituting the original pseudo-range observed quantity into a pre-established pseudo-range double-difference observation equation to obtain the inter-frequency code deviation of the channel k of the receiver to be calibrated relative to the channel k of the reference receiver, wherein the pseudo-range double-difference observation equation is an inter-satellite receiver double-difference observation equation between the channel k and the channel 0 and between the reference receiver and the receiver to be calibrated, and k is not equal to 0.

In the embodiment of the disclosure, the reference receiver usually has only one receiver, and the number of receivers to be marked can be set according to actual needs. When the reference receiver exits the base station network due to faults and the like, any calibrated receiver in the base station network can be set as the reference receiver, and the other calibrated receivers do not need to be calibrated again at the moment; or, all the receivers in the base station network can be recalibrated according to the requirement, namely, one receiver is reselected to be a reference receiver, the other receivers are receivers to be calibrated, and the calibration is carried out according to the method to obtain the inter-frequency code deviation of the channel k of the receiver to be calibrated relative to the channel k of the reference receiver.

In some exemplary embodiments, the pre-established pseudorange double difference observation equation is:

wherein, the liquid crystal display device comprises a liquid crystal display device,

representing a double difference symbol; r and s respectively represent a reference receiver and a receiver to be calibrated; i represents a frequency point and can be 1 or 2; k and 0 are channel numbers, where k+.0; p is the pseudo-range observed quantity, and the unit is meter; ρ is the geometric distance of the satellite to the receiver; IFCB is inter-frequency code bias; v is the pseudorange observation noise. In particular, for all satellites with a channel of 0, the corresponding IFCB is 0.

In the embodiment of the disclosure, a pseudo-range single-difference observation equation between a reference receiver and a receiver to be calibrated is established firstly; and establishing a pseudo-range double-difference observation equation between the frequency channel k and the frequency channel 0 according to the established pseudo-range single-difference observation equation for each frequency channel k, wherein k is not equal to 0.

In the embodiment of the present disclosure, i=1 or 2, where i=1 represents an L1 frequency point and i=2 represents an L2 frequency point.

In some exemplary embodiments, obtaining raw pseudorange observations for all frequency channels includes:

acquiring original pseudo-range observed quantities of all channels in a preset time period;

for each frequency channel, calculating the average value of the original pseudo-range observed quantity in a preset time period to eliminate pseudo-range observed noise v.

In some exemplary embodiments, the preset time period is 24 hours.

In some exemplary embodiments, the calibration of the raw pseudorange observations is performed according to the determined inter-frequency code bias, specifically:

calibrating the raw pseudorange observables according to the following formula:

wherein (1)>

Representing the pre-stored inter-frequency code deviation,/of the kth channel of the ith frequency point of the receiver s to be calibrated>

Representing the original pseudo-range observed quantity of the kth frequency channel of the ith frequency point of the receiver s to be calibrated; />

And representing the calibrated pseudo-range observed quantity of the ith frequency point and the kth frequency channel of the receiver to be calibrated. In particular, channel 0 corresponds to an inter-frequency code deviation of 0, i.e. +.>

The calibration method of the pseudorange observables of the GLONASS system provided by the embodiments of the disclosure is described in detail below.

The reason for the GLONASS inter-frequency code bias is due to the FDMA mechanism used in the GLONASS navigation signals. The center frequencies of the GLONASSL1 frequency point and the L2 frequency point are 1602MHz and 1246MHz respectively. In order to make the signal frequencies of the GLONASS satellites tracked by the receiver different, each GLONASS satellite is assigned a channel number k, and the signal frequencies of L1 and L2 of the satellite are respectively (1602+kΔf) ₁ ) MHz sum (1246+kΔf) ₂ ) MHz. Wherein k may be any integer from-7 to 6, Δf ₁ ＝0.5625，Δf ₂ =0.4375. In particular, for a satellite with channel number k=0, the signal frequency is equal to the center frequency of the frequency point, and it can be considered that there is no inter-frequency code deviation in the observed quantity of the satellite, that is, the inter-frequency code deviation of the satellite with channel 0 is 0. Due to the problem of hardware component consistency, the inter-frequency code bias between two receivers of the same brand and same batch is different even if the channel number k (k not equal to 0) is the same observed quantity. The present disclosure compensates for receiver-to-receiver code bias by selecting one receiver as a reference receiverTo be consistent with the reference receiver. Thus, the code deviation among all the receivers of the networking can be ensured to be consistent. During calibration, the reference receiver and the receiver to be calibrated are connected to the same receiving antenna, the positions of the receiving antennas are known, data of all channel numbers are collected, the difference value of the inter-frequency code deviation of each frequency channel of the receiver to be calibrated and the reference receiver is calculated in a zero-base line double-difference mode, the difference value is input through a command and stored in the receiver to be calibrated, and the receiver to be calibrated compensates according to the stored difference value when the GLONASS pseudo-range observed quantity is output.

Equations (1) and (2) are pseudo-range observation equations of the reference receiver and the receiver to be calibrated at the glonasl 1 frequency point, respectively:

in formulas (1) and (2):

k is a channel number, and k can be any integer between-7 and 6;

r, s represent a reference receiver and a receiver to be calibrated respectively;

and->

Pseudo-range observables of a satellite k on a frequency point of a reference receiver and a receiver to be calibrated L1 are respectively obtained;

and->

Respectively a sampling time reference receiver and a receiver to be calibratedThe geometrical distance between the antenna of (a) and satellite k (the reference receiver and the receiver to be calibrated are different);

c is the speed of light in vacuum;

dT _r,1 and dT _s,1 The clock difference of the reference receiver and the receiver to be calibrated at the L1 frequency point is respectively;

Trop ^k tropospheric errors contained in the observed quantity;

Iono ^k ionospheric error contained for the observed quantity;

and->

Pseudo-range observed quantity noise of the reference receiver and the receiver to be calibrated is respectively obtained;

making a single difference between the co-frequency channels k of the receiver to be calibrated and the reference receiver, namely, the formula (2) -the formula (1) can be obtained:

in equation (3), because the ionospheric error and the tropospheric error are the same in both observables, the single difference can be eliminated.

For the difference between the pseudo-range observations of the receiver to be calibrated and the reference receiver, the pseudo-range observations are known quantities

Can be calculated. />

Is the difference in the geometrical distance of the antenna to satellite k. The antenna position is known and the satellite position can be calculated from the observation time and the broadcast ephemeris, thus +.>

Or by calculation. />

The difference value of the code deviation between the frequency of the receiver to be calibrated and the frequency of the reference receiver is the amount to be calculated. />

Is single difference observed quantity noise, is 0 mean white noise and can be eliminated through multi-epoch average. ΔdT _r,s,1 Is the difference between the two receiver clock differences, which is an unknown quantity.

In particular, for a satellite with channel number k=0, the following single difference observation equation can be obtained:

equations (3) and (4) both contain the difference ΔdT of the two receiver clock differences _r,s,1 If the satellite with k=0 is used as the reference satellite, the satellite with k=0 and the reference satellite are subjected to single difference (namely, formula (4) -formula (3)) again, so that the following double-difference observation equation can be obtained:

wherein the method comprises the steps of

Is a double difference symbol. The observation equation (5) eliminates the unknown ΔdT _r,s,1 Thus can calculate

The satellite with channel number k=0 has a signal frequency equal to 1602MHz of the center frequency of the glonasl 1 frequency, ifcb=0, and is used as a reference satellite without losing generality. For the satellite with the channel number k not equal to 0, the method can calculateIFCB offset value relative to reference receiver

Can eliminate observed quantity noise by multi-epoch averaging, improve +.>

Is a precision of (a). The method can collect observed quantity for 24 hours, can traverse satellites with all channel numbers, and can further improve +.>

The accuracy of the calculation.

For GLONASSL2 frequency point observables, the following observation equation can be obtained by the same method:

during data acquisition, GLONASSL1 and L2 frequency point pseudo-range observables can be acquired simultaneously,

and

the calculation of (2) may also be performed simultaneously. After calculating the inter-frequency code deviations of all channel numbers of two frequency points of the receiver to be calibrated, all the inter-frequency code deviations can be input through commands and stored in the receiver. In particular, for all satellites with channel number 0, the inter-frequency code deviation is 0, i.e.>

The receiver may calibrate based on the frequency point and the channel number of each pseudorange observation when subsequently outputting the GLONASS pseudorange observations:

and->

Pseudo-range observables after calibrating the frequency points of the satellite L1 and the satellite L2 with the channel number k are respectively represented, < >>

And->

And respectively representing the original pseudo-range observed quantity before the calibration of the L1 and L2 frequency points of the satellite.

According to the calibration method for the GLONSSSL (global navigation satellite system) pseudo-range observed quantity, a receiver is used as a reference, and the deviation of the inter-frequency code deviation of all channel numbers of all receivers GLONSSSL1 and L2 in a batch or one-time networking relative to the reference receiver is calculated; the inter-frequency code deviation of all channel numbers of each receiver GLONSSSL1 and L2 is input by naming relative to the deviation of a reference receiver and is stored in a storage device (such as a flash memory) of the corresponding receiver; before outputting GLONASS pseudo-range observables, the receiver reads corresponding inter-frequency code deviation values of the frequency points and the channel numbers from the storage device according to the frequency points and the channel numbers of the original pseudo-range observables, compensates the original pseudo-range observables and outputs the original pseudo-range observables; the inter-frequency code deviation of the compensated GLONASS pseudo-range observed quantity of all the receivers of the batch or the sub-network is the same as that of the reference receiver, so that the GLONASS inter-frequency code deviation of all the receivers of the batch or the sub-network is consistent, and the positioning precision of network RTK or PPP service is improved.

As shown in fig. 2, in one example, the calibration device for the pseudorange observables of the GLONASS system may include: the device comprises a processor 210, a memory 220, a bus system 230 and a transceiver 240, wherein the processor 210, the memory 220 and the transceiver 240 are connected through the bus system 230, the memory 220 is used for storing instructions, and the processor 210 is used for executing the instructions stored by the memory 220 to control the transceiver 240 to transmit and receive signals. Specifically, the transceiver 240 may obtain the original pseudo-range observed quantity under the control of the processor 210, the processor 210 obtains the frequency point and the frequency channel number of the original pseudo-range observed quantity, and determines the frequency-to-frequency code deviation corresponding to the frequency point and the frequency channel number of the original pseudo-range observed quantity; and calibrating the original pseudo-range observed quantity according to the determined inter-frequency code deviation, and outputting the calibrated pseudo-range observed quantity.

It should be appreciated that the processor 210 may be a central processing unit (Central Processing Unit, CPU), and the processor 210 may also be other general purpose processors, digital Signal Processors (DSPs), application Specific Integrated Circuits (ASICs), off-the-shelf programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

Memory 220 may include read only memory and random access memory and provides instructions and data to processor 210. A portion of memory 220 may also include non-volatile random access memory. For example, the memory 220 may also store information of the device type.

The bus system 230 may include a power bus, a control bus, a status signal bus, and the like in addition to a data bus. But for clarity of illustration the various buses are labeled in fig. 2 as bus system 230.

In implementation, the processing performed by the processing device may be performed by integrated logic circuits of hardware in processor 210 or by instructions in the form of software. That is, the method steps of the embodiments of the present disclosure may be embodied as hardware processor execution or as a combination of hardware and software modules in a processor. The software modules may be located in random access memory, flash memory, read only memory, programmable read only memory, or electrically erasable programmable memory, registers, and other storage media. The storage medium is located in the memory 220, and the processor 210 reads the information in the memory 220 and, in combination with its hardware, performs the steps of the method described above. To avoid repetition, a detailed description is not provided herein.

The embodiments of the present disclosure also provide a computer readable storage medium having stored thereon a computer program which, when executed by a processor, implements a method for calibrating pseudorange observations of a GLONASS system according to any of the embodiments of the present disclosure. The method for controlling the calibration of the pseudorange observables of the GLONASS system by executing the executable instructions is substantially the same as the method for calibrating the pseudorange observables of the GLONASS system provided in the above embodiment of the disclosure, and will not be described herein.

In some possible embodiments, various aspects of the calibration method for a pseudorange observance of a GLONASS system provided by the present disclosure may also be implemented in the form of a program product, which includes program code for causing a computer device to perform the steps of the calibration method for a pseudorange observance of a GLONASS system according to the various exemplary embodiments of the present disclosure described above when the program product is run on the computer device, for example, the computer device may perform the calibration method for a pseudorange observance of a GLONASS system described in the examples of the present disclosure.

The program product may employ any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. The readable storage medium may be, for example, but not limited to: an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or a combination of any of the foregoing. More specific examples (a non-exhaustive list) of the readable storage medium would include the following: an electrical connection having one or more wires, a portable disk, a hard disk, random Access Memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

Those of ordinary skill in the art will appreciate that all or some of the steps, systems, functional modules/units in the apparatus, and methods disclosed above may be implemented as software, firmware, hardware, and suitable combinations thereof. In a hardware implementation, the division between the functional modules/units mentioned in the above description does not necessarily correspond to the division of physical components; for example, one physical component may have multiple functions, or one function or step may be performed cooperatively by several physical components. Some or all of the components may be implemented as software executed by a processor, such as a digital signal processor or microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on computer readable media, which may include computer storage media (or non-transitory media) and communication media (or transitory media). The term computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data, as known to those skilled in the art. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital Versatile Disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by a computer. Furthermore, as is well known to those of ordinary skill in the art, communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media.

While the embodiments disclosed in the present disclosure are described above, the embodiments are only employed for facilitating understanding of the present disclosure, and are not intended to limit the present disclosure. Any person skilled in the art will recognize that any modifications and variations can be made in the form and detail of the present disclosure without departing from the spirit and scope of the disclosure, which is defined by the appended claims.

Claims

1. A method for calibrating pseudorange observations in a GLONASS system, comprising:

2. The method of calibrating according to claim 1, wherein prior to the step of determining the inter-frequency code bias corresponding to the frequency points and channel numbers of the raw pseudorange observations, the method of calibrating further comprises:

3. The method of calibration according to claim 2, wherein the inter-frequency code bias corresponding to each frequency bin and channel number is determined by:

determining a reference receiver and a receiver to be calibrated;

acquiring original pseudo-range observed quantities of all frequency channels when the reference receiver and the receiver to be calibrated are connected to the same antenna;

substituting the original pseudo-range observed quantity into a pre-established pseudo-range double-difference observation equation to obtain inter-frequency code deviation of the channel k of the receiver to be calibrated relative to the channel k of the reference receiver, wherein the pseudo-range double-difference observation equation is an inter-satellite receiver double-difference observation equation between the channel k and the channel 0 and between the reference receiver and the receiver to be calibrated, and k is not equal to 0.

4. A calibration method according to claim 3, wherein the pre-established pseudorange double difference observation equation is:

wherein, delta # -represents a double difference symbol; r and s respectively represent a reference receiver and a receiver to be calibrated; i represents a frequency point, and i can be 1 or 2; k and 0 are both channel numbers; p is the pseudo-range observed quantity, and the unit is meter; ρ is the geometric distance of the satellite to the receiver; IFCB is the inter-frequency code deviation, ifcb=0 corresponding to the satellite with channel number 0; v is the pseudorange observation noise.

5. A method of calibrating according to claim 3, wherein said obtaining raw pseudorange observations for all frequency channels comprises:

and calculating the average value of the original pseudo-range observed quantity in a preset time period for each frequency channel so as to eliminate pseudo-range observed noise.

6. The method of calibrating according to claim 5, wherein the preset time period is 24 hours.

7. The calibration method according to claim 1, wherein the calibrating the raw pseudorange observations according to the determined inter-frequency code bias is specifically:

calibrating the raw pseudorange observables according to the following formula:

wherein (1)>

Representing the original pseudo-range observed quantity of the kth frequency channel of the ith frequency point of the receiver s to be calibrated;

representing calibrated pseudo-range observations of a receiver to be calibrated s ith frequency point and kth frequency channel, wherein k is not equal to 0, and

8. a device for calibrating the pseudorange observations of a GLONASS system, comprising a memory; and a processor connected to the memory, the memory for storing instructions, the processor being configured to perform the steps of the method for calibrating pseudorange observations of the GLONASS system according to any of claims 1 to 7 based on the instructions stored in the memory.

9. A receiver of a GLONASS system, comprising a calibration device of a pseudorange observance of the GLONASS system according to claim 8.

10. A storage medium having stored thereon a computer program which, when executed by a processor, implements a method of calibrating pseudorange observations of a GLONASS system as claimed in any one of claims 1 to 7.