Calibration method, device, receiver and storage medium for glonass system pseudorange observation

Abstract

The embodiment of the present disclosure provides a GLONASS system pseudo-range observation calibration method, device, receiver and storage medium, the GLONASS system pseudo-range observation calibration method comprises: obtaining the frequency point and channel number of the original pseudo-range observation; determine the inter-frequency code bias corresponding to the frequency point and channel number of the original pseudo-range observation; according to the inter-frequency code bias determined, the original pseudo-range observation is calibrated, and the calibrated pseudo-range observation is output.The present disclosure can make the GLONASS inter-frequency code bias of all receivers in a reference station network consistent, and also make the GLONASS inter-frequency code bias of receivers of any brand consistent, thereby improving the positioning accuracy of network RTK or PPP service.

Description

Technical Field

[0001] This disclosure relates to, but is not limited to, the field of satellite navigation technology, and in particular to a calibration method, apparatus, receiver, and storage medium for pseudorange observations of a GLONASS system. Background Technology

[0002] A Global Navigation Satellite System (GNSS) is an artificial satellite system with multiple satellites that transmit signals containing position and time information to ground-based GNSS receivers, enabling the receivers to perform positioning. Currently, the major GNSS systems include the European Union's Galileo satellite navigation system, the United States' Global Positioning System (GPS), Russia's GLONASS satellite navigation system, China's BeiDou Navigation Satellite System, and Japan's Quasi-Zenith Satellite System (QZSS). Satellite navigation systems offer high positioning accuracy, global coverage, and are widely used in navigation, surveying and mapping, precision agriculture, intelligent robots, autonomous driving, and unmanned aerial vehicles (UAVs), among other fields.

[0003] Applications such as surveying and mapping, precision agriculture, intelligent robots, autonomous driving, and drones often require centimeter-level positioning accuracy. The main technologies providing centimeter-level satellite positioning services are Real-Time Kinematic (RTK) and Precise Point Positioning (PPP). RTK technology is currently the most widely used high-precision satellite positioning technology. RTK technology requires the support of base stations. Utilizing the correlation of errors between stations, the rover station uses base station observations to eliminate or reduce errors in satellite orbit, satellite clock bias, ionospheric, and tropospheric conditions, thereby achieving centimeter-level positioning accuracy. Satellite clock bias is independent of the distance between stations and can be completely eliminated; however, errors in satellite orbit, ionospheric, and tropospheric conditions are related to the distance between stations. The closer the distance between the base station and the rover station, the stronger the error correlation, and the smaller the residual after single-difference between the rover station and base station observations. The correlation weakens with greater distances. When the distance between the base station and the rover station exceeds a certain distance, such as 30 kilometers, atmospheric residuals reach the decimeter level, making it difficult to fix double-difference ambiguities and thus preventing centimeter-level positioning. To meet the needs of large-scale, high-precision applications such as precision agriculture, autonomous driving, and drones, multiple base stations are typically established to form a network, providing services to customers via network RTK. PPP technology, on the other hand, eliminates satellite orbit and clock errors in broadcast ephemeris data through precise satellite orbit and clock bias data. Ionospheric errors are eliminated through multi-frequency combinations, and tropospheric errors can be estimated using parameters. Some precise point positioning services also broadcast ionospheric and tropospheric data, which can also be used to mitigate ionospheric and tropospheric errors. Precise satellite orbit and clock bias also require a network of base stations distributed nationwide or even globally to acquire tracking data from each base station. Using the known locations of these base stations, the accurate coordinates and clock bias of the satellites—i.e., precise orbit and clock bias—as well as atmospheric parameters are calculated. Precise orbit and clock bias are often broadcast to users as ephemeris corrections to save bandwidth.

[0004] Network RTK requires users to report their approximate location before the server can send base station data based on that location. PPP, on the other hand, provides precise data applicable to all users and can therefore be transmitted via satellite broadcast. Within the service range of network RTK, network RTK is generally superior to PPP in terms of availability and accuracy, while PPP does not require users to report their location and has wider coverage. Network RTK and PPP can complement each other, providing users with higher availability.

[0005] Both network RTK services and PPP services providing precise PPP data to users require the establishment of base station networks. Current base stations are full-system receivers. To distinguish signals transmitted by different satellites, GNSS navigation systems employ multiple access mechanisms. GPS, BDS, Galileo, and QZSS systems use Code Division Multiplexing (CDMA) for their navigation signals, while GLONASS navigation signals use Frequency Division Multiple Access (FDMA). Therefore, the frequencies of signals from multiple GLONASS satellites received simultaneously by the receiver are different. Signals at different frequencies at the same point will produce inter-frequency bias (IFB) in the receiver's observations. IFB is mainly caused by differences in hardware delays between signals of different frequencies in the receiver. IFB exists in both pseudorange and carrier observations. The IFB of pseudorange observations is generally called inter-frequency code bias (IFCB). The inter-frequency deviation of carrier observations is generally referred to as inter-frequency phase deviation (IFPB). Both IFB and IFB affect GLONASS-involved PPP and RTK positioning, as well as network RTK calculations and PPP precise orbit clock bias calculations. Currently, the main approach is to estimate the difference in inter-frequency deviation between receivers of different brands during RTK calculations. Some researchers have used PPP methods to estimate the GLONASS inter-frequency code deviation of multiple receiver brands with de-ionization combinations through pre-collected data for subsequent data calculations. However, even among receivers of the same brand, the inter-frequency code deviation varies due to hardware or software differences. Furthermore, even receivers from the same batch can exhibit different inter-frequency code deviations due to variations in hardware component consistency. Summary of the Invention

[0006] This disclosure provides a calibration method, apparatus, receiver, and storage medium for pseudorange observations of a GLONASS system. Through calibration, the GLONASS inter-frequency code deviation of all receivers in a reference station network can be made consistent, as can the GLONASS inter-frequency code deviation of receivers of the same brand.

[0007] This disclosure provides a method for calibrating pseudorange observations of a GLONASS system, including:

[0008] Obtain the frequency point and channel number of the original pseudorange observations;

[0009] Determine the inter-frequency code deviation corresponding to the frequency point and channel number of the original pseudorange observation;

[0010] The original pseudorange observation is calibrated based on the determined inter-frequency code deviation, and the calibrated pseudorange observation is output.

[0011] This disclosure also provides a calibration apparatus for pseudorange observations of a GLONASS system, including a memory; and a processor connected to the memory, the memory being used to store instructions, the processor being configured to perform the steps of a calibration method for pseudorange observations of a GLONASS system as described in any embodiment of this disclosure based on the instructions stored in the memory.

[0012] This disclosure also provides a GLONASS system receiver, including a calibration device for GLONASS system pseudorange observations as described in any embodiment of this disclosure.

[0013] This disclosure also provides a storage medium storing a computer program that, when executed by a processor, implements the calibration method for pseudorange observations of the GLONASS system as described in any embodiment of this disclosure.

[0014] The calibration method, apparatus, receiver, and storage medium for pseudorange observations of the GLONASS system provided in this disclosure calibrate the original pseudorange observations according to the pre-stored inter-frequency code deviations corresponding to each frequency point and channel number. This can make the GLONASS inter-frequency code deviations of all receivers in a base station network consistent, and can also make the GLONASS inter-frequency code deviations of receivers of any brand consistent, thereby improving the positioning accuracy of network RTK or PPP services.

[0015] Other features and advantages of this disclosure will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the disclosure. Other advantages of this disclosure may be realized and obtained by means of the embodiments described in the description, claims, and drawings. Attached Figure Description

[0016] The accompanying drawings are used to provide an understanding of the technical solutions of this disclosure and form part of the specification. They are used together with the embodiments of this disclosure to explain the technical solutions of this disclosure and do not constitute a limitation on the technical solutions of this disclosure.

[0017] Figure 1 This is a flowchart illustrating a calibration method for pseudorange observations of a GLONASS system according to an embodiment of this disclosure.

[0018] Figure 2This is a schematic diagram of the structure of a calibration device for pseudorange observations of a GLONASS system according to an embodiment of this disclosure. Detailed Implementation

[0019] This disclosure describes several embodiments, but these descriptions are exemplary and not limiting, and it will be apparent to those skilled in the art that many more embodiments and implementations are possible within the scope of the embodiments described herein. 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 also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with, or may replace, any feature or element of any other embodiment.

[0020] This disclosure includes and contemplates combinations of features and elements known to those skilled in the art. The embodiments, features, and elements disclosed in this disclosure may also be combined with any conventional features or elements to form a unique inventive scheme as defined by the claims. Any feature or element of any embodiment may also be combined with features or elements from other inventive schemes to form another unique inventive scheme as defined by the claims. Therefore, it should be understood that any feature shown and / or discussed in this disclosure may be implemented individually or in any suitable combination. Therefore, the embodiments are not limited except by the limitations imposed by the appended claims and their equivalents. Furthermore, various modifications and changes may be made within the scope of the appended claims.

[0021] Furthermore, in describing representative embodiments, the specification may have presented methods and / or processes as a specific sequence of steps. However, the method or process should not be limited to the specific order of steps described in this disclosure to the extent that it does not depend on such a specific order. As will be understood by those skilled in the art, other sequences of steps are also possible. Therefore, the specific order of steps set forth in the specification should not be construed as a limitation of the claims. Moreover, the claims relating to the method and / or process should not be limited to the steps performed in the order written, and those skilled in the art will readily understand that these orders can be varied and still remain within the spirit and scope of the embodiments of this disclosure.

[0022] Both network RTK services and PPP services providing precise PPP data to users require the establishment of a base station network. The consistency of GLONASS inter-frequency code offsets across all base stations in the network significantly impacts network RTK and PPP precise orbit clock bias calculations. Maintaining consistent GLONASS inter-frequency code offsets across all base stations can greatly improve the speed of GLONASS ambiguity fixing in network RTK, thereby enhancing the availability of the network RTK service; and it can improve the accuracy of GLONASS orbit and clock bias calculations. Currently, in tracking station networking, the consistency of inter-frequency code offsets among base stations within the network is primarily improved by using receivers of the same brand. However, even receivers of the same brand and batch can exhibit different inter-frequency code offsets due to variations in hardware component consistency.

[0023] like Figure 1 As shown, this disclosure provides a method for calibrating pseudorange observations of a GLONASS system, including:

[0024] Step 101: Obtain the frequency point and channel number of the original pseudorange observations;

[0025] Step 102: Determine the inter-frequency code deviation corresponding to the frequency point and channel number of the original pseudorange observation;

[0026] Step 103: Calibrate the original pseudorange observation based on the determined inter-frequency code deviation, and output the calibrated pseudorange observation.

[0027] The calibration method for pseudorange observations of the GLONASS system provided in this disclosure calibrates the original pseudorange observations based on the pre-stored inter-frequency code deviations corresponding to each frequency point and channel number. This can make the GLONASS inter-frequency code deviations of all receivers in a base station network consistent, and can also make the GLONASS inter-frequency code deviations of receivers of any brand consistent, thereby improving the positioning accuracy of network RTK or PPP services.

[0028] In some exemplary embodiments, prior to the step of determining the inter-frequency code deviation corresponding to the frequency point and channel number of the original pseudorange observation, the calibration method further includes:

[0029] Determine the inter-frequency code offset corresponding to each frequency point and channel number;

[0030] Store the correspondence between each frequency point, channel number, and inter-frequency code deviation.

[0031] In this embodiment of the disclosure, when storing the correspondence between each frequency point, channel number, and inter-frequency code deviation, the determined correspondence between the frequency point, channel number, and inter-frequency code deviation can be stored in the receiver's storage device.

[0032] In some exemplary implementations, the inter-frequency code offset corresponding to each frequency point and channel number is determined in the following manner:

[0033] Identify the reference receiver and the receiver to be calibrated;

[0034] Obtain the raw pseudorange observations for all channels when the reference receiver and the receiver to be calibrated are connected to the same antenna;

[0035] Substituting the original pseudorange observations into the pre-established pseudorange double-difference observation equations, we obtain the inter-frequency code deviation of the receiver channel k to be calibrated relative to the reference receiver channel k. The pseudorange double-difference observation equations are the inter-satellite receiver double-difference observation equations between channel k and channel 0, and between the reference receiver and the receiver to be calibrated, where k≠0.

[0036] In this embodiment, there is typically only one reference receiver, and the number of receivers to be calibrated can be set according to actual needs. When the reference receiver leaves the base station network due to faults or other reasons, any calibrated receiver in the base station network can be set as the reference receiver. In this case, other calibrated receivers do not need to be recalibrated. Alternatively, all receivers in the base station network can be recalibrated as needed, i.e., one receiver is reselected as the reference receiver, and the others are receivers to be calibrated. Calibration is performed according to the aforementioned 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.

[0037] In some exemplary embodiments, the pre-established pseudorange double-difference observation equation is:

[0038]

[0039] in, The symbol represents the double difference; r and s represent the reference receiver and the receiver to be calibrated, respectively; i represents the frequency point, which can be 1 or 2; k and 0 are both channel numbers, where k ≠ 0; P is the pseudorange observation measurement in meters; ρ is the geometric distance from the satellite to the receiver; IFCB is the inter-frequency code offset; v is the pseudorange observation noise. Specifically, for all satellites with channel 0, the corresponding IFCB is 0.

[0040] In this embodiment of the disclosure, a pseudorange single-difference observation equation is first established between the reference receiver and the receiver to be calibrated; then, for each channel k, a pseudorange double-difference observation equation is established between channel k and channel 0 based on the established pseudorange single-difference observation equation, wherein k≠0.

[0041] In this embodiment of the disclosure, i = 1 or 2, where i = 1 represents the L1 frequency point and i = 2 represents the L2 frequency point.

[0042] In some exemplary implementations, obtaining the raw pseudorange observations for all channels includes:

[0043] Obtain the raw pseudorange observations of all channels within a preset time period;

[0044] For each channel, the average value of the original pseudorange observations within a preset time period is calculated to eliminate pseudorange observation noise v.

[0045] In some exemplary implementations, the preset time period is 24 hours.

[0046] In some exemplary embodiments, the original pseudorange observation is calibrated based on the determined inter-frequency code deviation, specifically as follows:

[0047] The original pseudorange observation is calibrated according to the following formula:

[0048] in, This represents the pre-stored inter-frequency code deviation of the receiver s at the i-th frequency point and the k-th channel. This represents the original pseudorange observation of the i-th frequency point and k-th channel of the receiver s to be calibrated; This represents the calibrated pseudorange observation at the i-th frequency and k-th channel of the receiver s to be calibrated. Specifically, the inter-frequency code deviation corresponding to channel 0 is 0, i.e.

[0049] The calibration method for pseudorange observations of the GLONASS system provided in the embodiments of this disclosure will be described in detail below.

[0050] The inter-frequency code deviation in GLONASS is caused by the FDMA mechanism used in GLONASS navigation signals. The center frequencies of GLONASS SSL1 and L2 are 1602MHz and 1246MHz, respectively. To ensure that the GLONASS satellite signals tracked by the receivers simultaneously have different frequencies, each GLONASS satellite is assigned a channel number k. The signal frequencies of L1 and L2 of this satellite are (1602+kΔf1)MHz and (1246+kΔf2)MHz, respectively. Here, k can be any integer from -7 to 6, Δf1 = 0.5625, and Δf2 = 0.4375. Specifically, for satellites with channel number k = 0, their signal frequency is equal to the center frequency of that channel, and it can be assumed that there is no inter-frequency code deviation for the observations of this satellite; that is, the inter-frequency code deviation for satellites with channel number 0 is 0. Due to inconsistencies in hardware components, even two receivers of the same brand and batch, even with the same channel number k (k≠0), will have different inter-frequency code deviations in their observations. This disclosure selects a receiver as a reference receiver and compensates the inter-frequency code deviation of the receiver to be calibrated to match that of the reference receiver. This ensures that the inter-frequency code deviation of all receivers in the network is consistent. During calibration, the reference receiver and the receiver to be calibrated are connected to the same receiving antenna, the location of which is known. Data for all channel numbers is collected, and the difference in inter-frequency code deviation between the receiver to be calibrated and the reference receiver for each frequency channel is calculated using a zero-baseline double-difference method. The difference is input via command and stored in the receiver to be calibrated. When the receiver to be calibrated outputs GLONASS pseudorange measurements, it compensates based on the stored difference.

[0051] Equations (1) and (2) are the pseudorange observation equations for the reference receiver and the receiver to be calibrated at the GLONASSL1 frequency, respectively:

[0052]

[0053]

[0054] In formulas (1) and (2):

[0055] k is the channel number, and k can be any integer between -7 and 6;

[0056] r and s represent the reference receiver and the receiver to be calibrated, respectively;

[0057] and These are the pseudorange observations of satellite k at frequency L1 of the reference receiver and the receiver to be calibrated, respectively.

[0058] and These are the geometric distances from the antennas of the reference receiver and the receiver to be calibrated to satellite k at the sampling time, respectively (the reference receiver and the receiver to be calibrated are different);

[0059] c is the speed of light in a vacuum;

[0060] dT r,1 and dT s,1 These are the receiver clock differences at frequency L1 for the reference receiver and the receiver to be calibrated, respectively.

[0061] Trop k This refers to the tropospheric error included in the observations;

[0062] Iono k This refers to the ionospheric error included in the observations;

[0063] and These are the pseudorange observation noises of the reference receiver and the receiver to be calibrated, respectively.

[0064] By performing a single difference between the same frequency channel k of the receiver to be calibrated and the reference receiver, i.e., by subtracting formula (1) from formula (2), we can obtain:

[0065]

[0066] In formula (3), since the ionospheric error and tropospheric error are the same in the two observations, the single difference can be eliminated. The difference between the pseudorange observations of the receiver to be calibrated and the reference receiver is given. Since the pseudorange observations are known quantities, therefore... It can be calculated. Let be the difference in geometric distance from the antenna to satellite k. The antenna position is known, and the satellite position can be calculated based on the observation time and broadcast ephemeris. It can also be calculated. The difference between the inter-frequency code deviation between the receiver to be calibrated and the reference receiver is the quantity to be calculated. It is single-difference observation noise, which is zero-mean white noise and can be eliminated by multi-epoch averaging. ΔdT r,s,1 It is the difference in clock bias between the two receivers, and is an unknown quantity.

[0067] Specifically, for satellites with channel number k=0, the following single-difference observation equation can be obtained:

[0068]

[0069] Both formulas (3) and (4) include the difference ΔdT between the two receiver clock errors. r,s,1If we take the satellite with k=0 as the reference satellite, and perform another single difference (i.e., formula (4)-formula (3)) between the satellites with k≠0 and the reference satellite, we can obtain the following double difference observation equation:

[0070]

[0071] in The sign is double difference. The observation equation (5) eliminates the unknown ΔdT. r,s,1 Therefore, it is possible to calculate

[0072] For satellites with channel number k=0, whose signal frequency is equal to the center frequency of 1602MHz of the GLONASSL1 frequency point, their IFCB=0, making them a generally applicable reference satellite. For satellites with channel number k≠0, the IFCB deviation value relative to the reference receiver can be calculated. Multi-epoch averaging can be used to eliminate observation noise and improve... The accuracy is high. It can typically collect 24-hour observations, cover satellites of all channels, and can further improve accuracy. The accuracy of the calculation.

[0073] For the GLONASSL2 frequency observations, the same method can be used to obtain the following observation equations:

[0074]

[0075] During data acquisition, pseudorange observations at GLONASSL1 and L2 frequencies can be acquired simultaneously. and The calculations can also be performed simultaneously. After calculating the inter-frequency code deviations for all channel numbers at the two frequency points of the receiver to be calibrated, all inter-frequency code deviations can be input and stored in the receiver via command. Specifically, for all satellites with channel number 0, their inter-frequency code deviation is 0, i.e. The receiver can then be calibrated based on the frequency and channel number of each pseudorange observation when outputting subsequent GLONASS pseudorange measurements.

[0076]

[0077]

[0078] in, and These represent the pseudorange observations after calibration at frequency points L1 and L2 of satellite channel number k. and These represent the original pseudorange observations of the satellite before calibration at the L1 and L2 frequencies, respectively.

[0079] The GLONASS pseudorange observation calibration method provided in this embodiment uses a single receiver as a reference to calculate the inter-frequency code deviation of all channel numbers of GLONSSSL1 and L2 for all receivers in a batch or a single network relative to the reference receiver. The inter-frequency code deviation of all channel numbers of GLONSSSL1 and L2 for each receiver relative to the reference receiver is input by name and stored in the corresponding receiver's storage device (e.g., flash memory). Before outputting GLONASS pseudorange observations, the receiver reads the corresponding inter-frequency code deviation value for the frequency and channel number from the storage device based on the original pseudorange observation's frequency and channel number, and compensates for it in the original pseudorange observation before outputting. The compensated inter-frequency code deviation of the GLONASS pseudorange observations for all receivers in the batch or network is the same as that of the reference receiver, thus ensuring that the GLONASS inter-frequency code deviation of all receivers in the batch or network is consistent, thereby improving the positioning accuracy of network RTK or PPP services.

[0080] This disclosure also provides a calibration apparatus for pseudorange observations of a GLONASS system, including a memory; and a processor connected to the memory, the memory being used to store instructions, the processor being configured to perform the steps of a calibration method for pseudorange observations of a GLONASS system as described in any embodiment of this disclosure based on the instructions stored in the memory.

[0081] like Figure 2 As shown, in one example, the calibration device for pseudorange observations of a GLONASS system may include: a processor 210, a memory 220, a bus system 230, and a transceiver 240. The processor 210, memory 220, and transceiver 240 are connected via the bus system 230. The memory 220 stores instructions, and the processor 210 executes the instructions stored in the memory 220 to control the transceiver 240 to transmit and receive signals. Specifically, the transceiver 240, under the control of the processor 210, acquires the original pseudorange observations. The processor 210 acquires the frequency point and channel number of the original pseudorange observations, determines the inter-frequency code deviation corresponding to the frequency point and channel number of the original pseudorange observations, calibrates the original pseudorange observations according to the determined inter-frequency code deviation, and outputs the calibrated pseudorange observations.

[0082] It should be understood that processor 210 can be a central processing unit (CPU), or it can 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 can be a microprocessor or any conventional processor.

[0083] 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, memory 220 may also store device type information.

[0084] In addition to a data bus, the bus system 230 may also include a power bus, a control bus, and a status signal bus. However, for clarity, in... Figure 2 The general labeled all buses as Bus System 230.

[0085] In implementation, the processing performed by the processing device can be accomplished through integrated logic circuits in the hardware of the processor 210 or through software instructions. That is, the method steps of this embodiment can be executed by a hardware processor, or by a combination of hardware and software modules within the processor. The software modules can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other storage media. This storage medium is located in memory 220, and the processor 210 reads information from memory 220 and, in conjunction with its hardware, completes the steps of the aforementioned method. To avoid repetition, further details are omitted here.

[0086] This disclosure also provides a GLONASS system receiver, including a calibration device for GLONASS system pseudorange observations as described in any embodiment of this disclosure.

[0087] This disclosure also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the GLONASS system pseudorange observation calibration method as described in any embodiment of this disclosure. The method for controlling the calibration of GLONASS system pseudorange observations by executing executable instructions is essentially the same as the GLONASS system pseudorange observation calibration method provided in the above embodiments of this disclosure, and will not be described in detail here.

[0088] In some possible implementations, various aspects of the GLONASS system pseudorange observation calibration method provided in this disclosure can also be implemented as a program product comprising program code that, when run on a computer device, causes the computer device to perform the steps in the GLONASS system pseudorange observation calibration method according to various exemplary embodiments of this disclosure as described above. For example, the computer device can execute the GLONASS system pseudorange observation calibration method described in the embodiments of this disclosure.

[0089] The program product may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: 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), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0090] It will be understood by those skilled in the art that all or some of the steps, systems, or apparatuses disclosed above, and their functional modules / units, can be implemented as software, firmware, hardware, or suitable combinations thereof. In hardware implementations, the division between functional modules / units mentioned above does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed collaboratively by several physical components. Some or all 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 (ASIC). Such software may be distributed on a computer-readable medium, which may include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and can be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0091] While the embodiments disclosed herein are as described above, the content is merely for the purpose of facilitating understanding of this disclosure and is not intended to limit this disclosure. Any person skilled in the art may make any modifications and changes to the form and details of the implementation without departing from the spirit and scope of this disclosure; however, the scope of patent protection of this disclosure shall still be determined by the scope defined in the appended claims.

Claims

1. A calibration method for pseudorange observations in a GLONASS system, characterized in that, include: Obtain the frequency point and channel number of the original pseudorange observations, determine the inter-frequency code deviation corresponding to each frequency point and channel number, and store the correspondence between each frequency point, channel number, and inter-frequency code deviation. The inter-frequency code deviation corresponding to each frequency point and channel number is determined as follows: determine the reference receiver and the receiver to be calibrated; obtain the original pseudorange observations for all channels when the reference receiver and the receiver to be calibrated are connected to the same antenna; substitute the original pseudorange observations into the pre-established pseudorange double-difference observation equation to obtain the channel of the receiver to be calibrated. Relative to the reference receiver channel The inter-frequency code deviation, wherein the pseudorange double-difference observation equation is the channel The inter-satellite receiver double-difference observation equations between channel 0 and between the reference receiver and the receiver to be calibrated. ≠0; Determine the inter-frequency code deviation corresponding to the frequency point and channel number of the original pseudorange observation; The original pseudorange observation is calibrated based on the determined inter-frequency code deviation, and the calibrated pseudorange observation is output.

2. The calibration method according to claim 1, characterized in that, The pre-established pseudorange double-difference observation equation is as follows: ； in, Indicates the double difference symbol; and These represent the reference receiver and the receiver to be calibrated, respectively. Indicates frequency point, It can be 1 or 2; Both 0 and 0 are channel numbers; P is the pseudorange observation, in meters; This represents the geometric distance from the satellite to the receiver. For inter-frequency code offset, the IFCB corresponding to a satellite with channel number 0 is 0; This is pseudorange observation noise.

3. The calibration method according to claim 1, characterized in that, The acquisition of the raw pseudorange observations for all channels when the reference receiver and the receiver to be calibrated are connected to the same antenna includes: Obtain the raw pseudorange observations for all channels when the reference receiver and the receiver to be calibrated are connected to the same antenna within a preset time period; For each channel, the average value of the original pseudorange observations within a preset time period is calculated to eliminate pseudorange observation noise.

4. The calibration method according to claim 3, characterized in that, The preset time period is 24 hours.

5. The calibration method according to claim 1, characterized in that, The calibration of the original pseudorange observation based on the determined inter-frequency code deviation specifically involves: The original pseudorange observation is calibrated according to the following formula: ;in, This indicates a pre-stored receiver to be calibrated. Inter-frequency code deviation of the i-th frequency point and the k-th channel Indicates the receiver to be calibrated The original pseudorange observations of the i-th frequency point and the k-th channel; Indicates the receiver to be calibrated The calibrated pseudorange observation at frequency i, channel k, where... ≠0, and =0.

6. A calibration device for pseudorange observations in a GLONASS system, characterized in that, It includes a memory; and a processor connected to the memory, the memory being used to store instructions, the processor being configured to perform the steps of the calibration method for pseudorange observations of the GLONASS system as described in any one of claims 1 to 5 based on the instructions stored in the memory.

7. A GLONASS system receiver, characterized in that, It includes the calibration device for pseudorange observations of the GLONASS system as described in claim 6.

8. A storage medium, characterized in that, It stores a computer program that, when executed by a processor, implements the calibration method for pseudorange observations of the GLONASS system as described in any one of claims 1 to 5.

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