A navigation device based on a dual-time system of satellite navigation receivers

Abstract

This invention provides a navigation device based on a dual-time system of a satellite navigation receiver. The navigation device includes a receiver and a host computer. The receiver includes an autonomous time system and an auxiliary time system. The autonomous time system is used to capture publicly available BeiDou signals, extract a first timestamp from the publicly available BeiDou signals, and parse the publicly available BeiDou signals to obtain first positioning information. The auxiliary time system is used to acquire external timing information, capture BeiDou authorized signals based on the external timing information, and parse the BeiDou authorized signals to obtain second positioning information. The host computer is used to perform navigation based on the first positioning information, or, if the second positioning information exists, to perform navigation based on the first positioning information and / or the second positioning information.

Description

Technical Field

[0001] This invention relates to the field of satellite navigation technology. More specifically, it relates to a navigation device based on a dual-time system of a satellite navigation receiver. Background Technology

[0002] As a core terminal product in the BeiDou Navigation Satellite System, the satellite navigation receiver's core function is to capture and track BeiDou satellite signals in real time and complete positioning calculations. It provides stable position, velocity, and time (PVT) and other positioning information to the host computer in a timely manner and is widely used in various fields such as vehicle navigation, surveying and mapping monitoring, UAV navigation, and ship scheduling.

[0003] Currently, BeiDou satellite navigation receivers generally adopt a single-time system positioning mode. In this mode, the receiver's positioning frequency selection is strongly tied to the validity of the BeiDou time information provided by the host computer, and the receiver itself does not have a fixed reference time. Its time information is obtained only through two means: one is that the receiver autonomously receives publicly available BeiDou signal frequencies and independently calculates information such as position, velocity, and time; the other is that it relies on the timing information provided by the host computer to assist in capturing authorized BeiDou signal frequencies and completing positioning.

[0004] In single-time system positioning mode, the receiver operates in two modes depending on the timing information provided by the host computer: if the host computer does not provide external timing information, the receiver autonomously receives publicly available BeiDou signal frequencies to achieve positioning; if the host computer provides external timing information, the receiver acquires and positions itself based on the authorized BeiDou signal frequencies. However, this mode has the following drawbacks: if the external timing information has significant deviations, it will affect the receiver's acquisition of authorized BeiDou signals, causing the receiver to fail to position itself correctly and unable to provide stable positioning information to the host computer, resulting in poor fault tolerance and reliability. Summary of the Invention

[0005] The purpose of this invention is to provide a navigation device based on a dual-time system of a satellite navigation receiver, so as to solve at least one of the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a navigation device based on a dual-time system of a satellite navigation receiver. The navigation device includes a receiver and a host computer. The receiver includes an autonomous time system and an auxiliary time system. The autonomous time system is used to capture publicly available BeiDou signals, extract a first timestamp from the publicly available BeiDou signals, and parse the publicly available BeiDou signals to obtain first positioning information. The auxiliary time system is used to acquire external time information, capture BeiDou authorization signals based on the external time information, and parse the BeiDou authorization signals to obtain second positioning information. The host computer is used to perform navigation based on the first positioning information, or, if the second positioning information exists, to perform navigation based on the first positioning information and / or the second positioning information.

[0007] Optionally, the receiver is used to output first positioning information or second positioning information to the host computer at a preset period.

[0008] Optionally, the auxiliary time system is used to obtain external time synchronization information from the BeiDou ground time synchronization base station through the host computer.

[0009] Optionally, the host computer is used to select either the first positioning information or the second positioning information for navigation based on preset navigation scenario information when the second positioning information is available.

[0010] Optionally, the host computer is used to perform navigation by fusing the first positioning information and the second positioning information when the second positioning information is available.

[0011] Optionally, the host computer is configured to select either the first positioning information or the second positioning information for navigation in response to a manual instruction, provided that the second positioning information is available.

[0012] Optionally, the autonomous time system is used to analyze the publicly available BeiDou signals based on the least squares method to obtain first positioning information.

[0013] Optionally, the auxiliary time system is used to analyze the BeiDou licensed signal based on the carrier phase differential positioning method to obtain second positioning information.

[0014] Optionally, the first positioning information and the second positioning information respectively include location information, time information and speed information.

[0015] The beneficial effects of this invention are as follows: Compared with navigation devices based on a single-time system of a satellite navigation receiver in related technologies, the navigation device based on a dual-time system of a satellite navigation receiver provided by the present invention has the following advantages: Positioning fault tolerance and reliability are greatly improved: Through the design of dual independent time systems, the lack of external time information or gross deviation will only affect the operation of the auxiliary time system and will not be transmitted to the autonomous time system, thus solving the problem of receiver positioning failure caused by external time anomalies in related technologies.

[0016] The dual systems are independent and interference-free, resulting in a more stable workflow: The autonomous time system and the auxiliary time system have independent time bases and workflows, working in parallel without affecting each other. An anomaly in one system will not affect the other, ensuring the stability of the receiver positioning process.

[0017] Supports dual-frequency positioning, providing richer output information: When external timing information is valid, it can achieve effective positioning of both BeiDou public signals and BeiDou authorized signals, providing the host computer with multi-dimensional positioning information of meter-level basic positioning and centimeter-level high-precision positioning, meeting the different application needs of civilian general scenarios, professional high-precision scenarios, etc., and the host computer can realize intelligent selection and dynamic switching of positioning results.

[0018] The two systems are independent of each other and have no reference coupling: the timing judgment and signal acquisition of the auxiliary time system do not depend on the time calculation results of the autonomous time system at all, avoiding the propagation of single-point failures; when there is a gross deviation in the external time synchronization, the autonomous time system can still perform calculations independently, ensuring the stability of the positioning function and maximizing the fault tolerance and reliability of the receiver.

[0019] Low startup threshold and strong adaptability: The autonomous time system starts up immediately upon power-up without any external assistance. The receiver can quickly achieve basic positioning after power-on, adapting to various application scenarios such as no external time synchronization or time synchronization delay, making it more widely applicable. Attached Figure Description

[0020] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0021] Figure 1 This diagram illustrates a navigation device based on a dual-time system of a satellite navigation receiver, as provided in an embodiment of the present invention.

[0022] Figure 2 This diagram illustrates the workflow of a navigation device based on a dual-time system of a satellite navigation receiver, as provided in an embodiment of the present invention. Detailed Implementation

[0023] To more clearly illustrate the present invention, the following description, in conjunction with embodiments and accompanying drawings, further explains the invention. Similar components in the drawings are indicated by the same reference numerals. Those skilled in the art should understand that the specific description below is illustrative rather than restrictive and should not be construed as limiting the scope of protection of the present invention.

[0024] In the description of this invention, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0025] It should also be noted that in the description of this invention, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0026] To address the technical deficiencies of single-time system positioning modes in related technologies, this invention provides a navigation device based on a dual-time system of a satellite navigation receiver. This device ensures that the positioning function remains unaffected even when there are significant deviations or no accurate timing information from external time synchronization, continuously providing stable and effective positioning information such as position, speed, and time to the host computer. Simultaneously, it supports effective positioning using both publicly available and authorized BeiDou signals at dual frequencies, improving the receiver's adaptability and positioning effectiveness.

[0027] like Figure 1 As shown, an embodiment of the present invention provides a navigation device based on a dual-time system of a satellite navigation receiver, including a receiver 10 and a host computer 20. The receiver 10 includes an autonomous time system 101 and an auxiliary time system 102. Autonomous time system 101 is used to capture BeiDou public signals, extract the first timestamp from the BeiDou public signals and parse the BeiDou public signals to obtain the first positioning information; The auxiliary time system 102 is used to acquire external time information and, if the external time information is valid, capture the BeiDou authorization signal according to the external time information and parse the BeiDou authorization signal to obtain the second positioning information. The host computer 20 is used for navigation based on the first positioning information, or for navigation based on the first positioning information and / or the second positioning information if second positioning information exists.

[0028] In the navigation device provided in this embodiment of the invention, the receiver 10 has two built-in time systems: an autonomous time system 101 and an auxiliary time system 102, which are independent and operate in parallel. Each system has its own independent time reference and workflow, and they do not interfere with each other. The autonomous time system 101 is responsible for acquiring, tracking, and calculating the positioning of publicly available BeiDou signal frequencies, while the auxiliary time system 102 is responsible for acquiring, tracking, and calculating the positioning of authorized BeiDou signal frequencies. The receiver 10 outputs effective information such as positioning and velocity according to a preset positioning calculation cycle.

[0029] The receiver 10's built-in autonomous time system 101 and auxiliary time system 102 operate independently and in parallel. Their overall working principle is as follows: The auxiliary time system 102 receives external time synchronization information provided by the host computer 20. If the time synchronization information is deemed valid, it acquires, tracks, and calculates the BeiDou authorized signal frequency based on this information, outputting high-precision positioning information. If the time synchronization information is invalid, the auxiliary time system 102 stops operating. The receiver 10 outputs positioning information according to a preset calculation cycle. When both systems operate in parallel, it outputs dual-frequency positioning information; when a single system operates, it outputs public signal frequency positioning information. After the dual-frequency positioning information is output, the host computer 20 selects the final positioning result.

[0030] Although the autonomous time system 101 can calculate a precise BeiDou absolute timestamp from publicly available BeiDou signals, this embodiment still designs an auxiliary time system 102 to capture BeiDou authorized signals based on external time synchronization information. The reasons for this include the difference in positioning accuracy between publicly available and authorized BeiDou signals, the technical characteristics of acquiring authorized signals, and the accuracy advantage of external time synchronization over the autonomous system's timestamp, as detailed below: BeiDou public signals (such as B1I) are civilian general-purpose signals. Their signal modulation methods, broadcast power, and data rate designs are all geared towards mass application scenarios. The positioning results obtained by receiver 10 through the calculation of such signals can only achieve meter-level accuracy, which can meet the basic positioning needs of vehicle navigation, general location monitoring, etc., but cannot meet the high-precision positioning scenarios that require centimeter-level or millimeter-level positioning accuracy, such as surveying and mapping monitoring, precision engineering construction, and military applications. BeiDou authorized signals (such as B3I) are high-precision confidential signals. They use more accurate carrier phase observation values ​​and better signal modulation methods. After calculation, they can achieve centimeter-level or even millimeter-level positioning accuracy. They are the core signal source for high-precision positioning scenarios. This is also the core consideration for the auxiliary time system 102 to be designed specifically for BeiDou authorized signals.

[0031] As a high-precision signal with confidentiality attributes, the acquisition threshold of BeiDou authorized signals is significantly higher than that of public signals: public signals use non-coherent acquisition methods, and receiver 10 can quickly lock the signal through blind search and coarse acquisition without the need for precise prior time information; while authorized signals use coherent acquisition methods, which must rely on precise BeiDou absolute timestamps as prior information in order to quickly lock the carrier frequency and code phase of the signal. If this precise prior time information is lacking, the acquisition process of authorized signals by receiver 10 will take too long, or even fail to achieve effective acquisition, thus losing the real-time requirement of high-precision positioning.

[0032] Although the autonomous time system can output a precise BeiDou absolute timestamp, this embodiment still uses external time synchronization as the core time reference for the auxiliary time system, rather than using the timestamp of the autonomous system. The reason is that external time synchronization information (such as time synchronization information provided by BeiDou ground time synchronization base stations and professional time synchronization servers) has higher time accuracy and stability, reaching the microsecond level, and can keep synchronized with the overall system time of the host computer 20, meeting the requirements of high-precision positioning for system time consistency; while the timestamp of the autonomous system is calculated from the public signal, and this timestamp is only the local time of the receiver 10, which cannot be synchronized with the system time of the host computer 20.

[0033] The workflow of the navigation device provided in this embodiment is as follows: Figure 2 As shown, its design logic is as follows: the autonomous system calculates the public signal and outputs meter-level positioning results to achieve the positioning backup function; the auxiliary system relies on higher-precision external time synchronization information (when it is determined to be valid) to use the external time synchronization information as prior information to quickly capture the authorized signal, and then calculates the centimeter-level high-precision positioning result to meet the high-precision requirements of professional scenarios; the combination of the dual time system not only realizes the continuous positioning function, but also meets the differentiated positioning accuracy requirements of different scenarios, while ensuring the real-time acquisition of the authorized signal and the consistency of system time.

[0034] In one possible implementation, the auxiliary time system determines whether the acquired external time synchronization information is valid, specifically including: Parse the data packets of the external timing information and extract the timing status flag bits; If the timing status flag indicates a valid state, then the external timing information is determined to be valid.

[0035] Specifically, the validity determination mechanism for external time synchronization information is as follows: After receiving external time synchronization information from the host computer, the auxiliary time system parses the data packets of the external time synchronization information, such as serial port protocol packets or network communication packets, and extracts the time synchronization status flag bit carried in the packet. If the time synchronization status flag bit indicates a valid state, for example, the flag bit displays a valid identifier, a healthy state, or a verification passed, the auxiliary time system determines that the acquired external time synchronization information is valid, and then updates the local time with the external time synchronization information, and starts the coherent acquisition and positioning calculation process of the BeiDou authorized signal based on this time reference; if the time synchronization status flag bit indicates an invalid state or the complete packet data is not received, the time synchronization is determined to be invalid. At this time, the auxiliary time system does not perform the acquisition operation of the authorized signal, and this determination process and the working state of the auxiliary time system will not affect the normal positioning calculation of the autonomous time system.

[0036] In one possible implementation, the first positioning information and the second positioning information respectively include location information, time information, and speed information.

[0037] The autonomous time system 101 is the basic positioning system of the receiver 10. After the receiver 10 is powered on, the system can start up and work normally without relying on any external auxiliary conditions. It can independently complete the acquisition, tracking and positioning calculation process of the Beidou public signal frequency points, and output positioning information such as position, speed and time in real time. Moreover, its operation process is not affected by external time information, providing a basic and stable positioning backup guarantee for the receiver 10.

[0038] The auxiliary time system 102 is a high-precision positioning system for the receiver 10, specifically responsible for the acquisition, tracking, and positioning calculation of the BeiDou authorized signal frequency points. Its startup and operation rely on externally provided BeiDou time synchronization information. After receiving external time synchronization information, the auxiliary time system 102 first updates the local time with the time synchronization information to establish a precise BeiDou time reference, and then completes the acquisition and positioning calculation of the BeiDou authorized signal frequency points based on this time reference. If no external time synchronization information is received, the auxiliary time system 102 stops working, and the receiver 10 only achieves positioning function through the autonomous time system 101.

[0039] The specific process by which the auxiliary time system 102 captures the BeiDou authorized signal based on external time synchronization information is as follows: First, the auxiliary time system 102 acquires external time synchronization information, and if the external time synchronization information is determined to be valid, it generates a time synchronization validity trigger signal. Subsequently, the auxiliary time system 102 receives the trigger signal, updates the BeiDou absolute time of its local clock based on the BeiDou timestamp in the external time information, calibrates the time deviation of the local crystal oscillator, and establishes a centimeter-level positioning time reference that is precisely synchronized with the BeiDou system. Next, based on the updated local BeiDou time reference, the prior acquisition parameters of the BeiDou licensed signal (such as B3I) are calculated. The prior acquisition parameters include the carrier frequency, pseudo-random code phase, and signal broadcast time of the licensed signal. Subsequently, the auxiliary timing system 102 sends the aforementioned prior acquisition parameters to the radio frequency front-end of the receiver 10, and configures the frequency synthesizer and code generator of the radio frequency front-end to achieve precise matching with the carrier frequency and code phase of the licensed signal; After receiving the BeiDou licensed signal, the radio frequency front-end performs coherent correlation calculation with the locally generated reference signal. When the correlation value exceeds the preset acquisition threshold, the coarse acquisition of the licensed signal is completed. After coarse acquisition, the signal fine tracking stage begins. The carrier phase and code phase of the licensed signal are locked through the carrier loop and code loop to achieve continuous and stable tracking of the licensed signal, providing continuous signal observations for subsequent high-precision positioning calculations.

[0040] If the auxiliary time system 102 does not receive external time synchronization information, or if the external time synchronization information is determined to be invalid, no parameter configuration or signal acquisition operation will be performed, and the radio frequency front end of the receiver 10 will not allocate relevant resources to the authorized signal acquisition module.

[0041] In one possible implementation, the auxiliary time system 102 updates the local time based on external time information and captures the BeiDou authorized signal using the updated local time as the time base.

[0042] In one possible implementation, if the external timing information is not obtained or the external timing information is biased, the autonomous time system 101 independently calculates the first positioning information.

[0043] In one possible implementation, the receiver 10 is used to output first positioning information or second positioning information to the host computer 20 at a preset period.

[0044] In one possible implementation, an auxiliary time system 102 is used to acquire external time synchronization information from the BeiDou ground time synchronization base station via a host computer 20.

[0045] Receiver 10 can flexibly switch positioning working modes according to the status and validity of the time synchronization information provided by host computer 20, and ensures that the autonomous time system 101 continues to work normally in all working modes. The specific working modes are as follows: One is the mode without external time synchronization. When the host computer 20 does not provide any external time synchronization information, the auxiliary time system 102 cannot be started. At this time, the receiver 10 only realizes the positioning function through the single autonomous time system 101 and continuously outputs effective positioning information based on the Beidou public signal frequency. The second is the timing deviation mode. When the external timing information provided by the host computer 20 is determined to have a gross deviation, only the positioning function of the auxiliary time system 102 fails, while the operation of the autonomous time system 101 is not affected in any way, and the receiver 10 still achieves normal positioning through the Beidou public signal frequency. Thirdly, there is a dual-system parallel mode. When the external timing information provided by the host computer 20 is valid and accurate, the autonomous time system 101 and the auxiliary time system 102 work normally at the same time. The receiver 10 can achieve effective positioning of the dual frequency points of the Beidou public signal frequency point and the Beidou authorized signal frequency point, and output the positioning information such as position and speed corresponding to the dual frequency points synchronously according to the preset positioning calculation cycle. The host computer 20 completes the selection and fusion processing of the final positioning result according to the actual application requirements.

[0046] In one possible implementation, the host computer 20 is used to select either the first or second positioning information for navigation based on preset navigation scenario information when the second positioning information is available.

[0047] In one possible implementation, the host computer 20 is used to perform navigation by fusing the first positioning information with the second positioning information when the second positioning information is available.

[0048] In one possible implementation, the host computer 20 is used to select either the first or second positioning information for navigation in response to a manual instruction, provided that the second positioning information is available.

[0049] In a specific example, the process of outputting positioning information and selecting results from the host computer 20 is as follows: The receiver 10 presets a fixed positioning calculation period, such as 1Hz or 10Hz. The positioning information output module outputs positioning information according to the working state of the dual-time system at the preset period. After receiving the positioning information, the host computer 20, based on the accuracy requirements of the application scenario, the stability of the positioning results, and preset business rules, completes the intelligent selection, dynamic switching, and fusion of the final positioning results.

[0050] When only the autonomous time system 101 is working, the positioning information output module only outputs meter-level basic positioning information for the publicly available BeiDou signal frequencies, and the host computer 20 directly uses this information as the final positioning result. When the autonomous time system 101 and the auxiliary time system 102 are working in parallel, the positioning information output module synchronously outputs meter-level basic positioning information for the publicly available BeiDou signal frequencies and centimeter-level high-precision positioning information for the authorized BeiDou signal frequencies. The host computer 20 selects the final positioning result in the following manner: The host computer 20 can pre-configure the corresponding rules of scenes and accuracy to achieve automatic matching of preset scenes. In general civilian scenarios such as vehicle navigation and ordinary location monitoring, meter-level basic positioning results are directly selected to reduce the computing load. In professional high-precision scenarios such as surveying and monitoring, military positioning, and precision construction, centimeter-level high-precision positioning results are forcibly selected to ensure the accuracy of the operation. In general compatible scenarios such as initial positioning of equipment, high-precision positioning results are selected by default.

[0051] The host computer 20 monitors the stability of the dual-system positioning results in real time and realizes dynamic switching of stability. If the high-precision positioning result shows abnormalities such as position jump, data packet loss, or accuracy decay, it will immediately and automatically switch to the basic positioning result. After the high-precision positioning result returns to normal, it will switch back to the high-precision positioning result. If the basic positioning result is abnormal, the high-precision positioning result will be continuously selected under the premise that the high-precision positioning result is normal, so as to ensure the continuity of positioning.

[0052] The host computer retains a manual configuration entry, supporting manual intervention and specification. Operators can manually lock or switch positioning results according to the actual situation on site, adapting to personalized needs such as equipment debugging, energy-saving operation, and special environments.

[0053] When both systems provide normal positioning results, the host computer 20 can perform fusion optimization processing on the dual-channel data. Taking the high-precision positioning result as the core, it combines the basic positioning result to correct random errors and outputs the optimal fused positioning result, thereby improving positioning stability.

[0054] The host computer 20 supports multiple output formats. It can output only the final selected positioning result according to business needs, or output dual positioning results and selection identifiers simultaneously. It can also output fused results and dual raw data to adapt to different business needs such as data transmission, tracing, and verification.

[0055] In one possible implementation, an autonomous time system 101 is used to analyze the publicly available BeiDou signals based on the least squares method to obtain first positioning information; and an auxiliary time system 102 is used to analyze the authorized BeiDou signals based on the carrier phase differential positioning method to obtain second positioning information.

[0056] In a specific example, after the receiver 10 is powered on, the autonomous time system 101 immediately enters the working state without relying on any external auxiliary conditions, independently completing the acquisition, tracking, and positioning calculation process of the BeiDou public signal frequency points. The specific process is as follows: The radio frequency front-end of the autonomous time system 101 performs a blind search on the BeiDou public signal frequency band, completing the incoherent coarse acquisition and fine tracking of the public signals, locking onto the public signals of at least four BeiDou satellites; the tracked public signals are demodulated, pseudorange observations are extracted, and satellite orbit parameters and satellite clock error parameters are extracted from the satellite broadcast ephemeris; based on the time information of the satellite broadcast ephemeris and the signal propagation time, the BeiDou absolute timestamp is calculated, and... The timestamp is continuously updated via a local crystal oscillator to achieve real-time output. The extracted pseudorange observations undergo routine error correction, including ionospheric delay correction, tropospheric delay correction, satellite clock bias correction, and Earth rotation effect correction. Using the least squares method, with the corrected pseudorange observations and satellite orbital parameters as input, a spatial distance equation is established to calculate the receiver 10's three-dimensional position coordinates (longitude, latitude, and altitude) and clock bias. Simultaneously, the velocity is calculated based on the continuous position calculation results or the Doppler frequency shift of the satellite signal. The autonomous time system 101 outputs meter-level basic positioning information to the positioning information output module, providing a backup positioning guarantee for the receiver 10.

[0057] In a specific example, after determining that the external time synchronization information is valid, the auxiliary time system 102 first updates the local time with the time synchronization information to establish a centimeter-level positioning time reference that is precisely synchronized with the BeiDou system. Then, based on this reference, it completes the acquisition, tracking, and high-precision positioning calculation of the BeiDou licensed signal frequency. The specific process is as follows: Based on the updated local BeiDou time reference, the prior acquisition parameters of the BeiDou licensed signal are calculated. The prior acquisition parameters include the carrier frequency, pseudo-random code phase, and signal broadcast time of the licensed signal. The prior acquisition parameters are sent to the radio frequency front-end of the receiver 10, and the frequency synthesizer and code generator of the radio frequency front-end are configured to achieve precise matching with the carrier frequency and code phase of the licensed signal. After receiving the BeiDou licensed signal, the radio frequency front-end performs coherent correlation calculation with the locally generated reference signal. When the correlation value exceeds the preset acquisition threshold, coarse acquisition is completed. Then, the carrier phase and code phase of the licensed signal are locked through the carrier loop and code loop. This system achieves continuous and stable tracking of the authorized signal; demodulates the tracked authorized signal, extracts carrier phase observations and pseudorange observations, and simultaneously extracts precise ephemeris parameters from the authorized signal broadcast; performs comprehensive high-precision error correction on the observations, including conventional corrections for ionospheric delay and tropospheric delay, as well as precise satellite orbit correction, high-precision calibration of receiver 10 clock bias, and preliminary resolution of carrier phase integer ambiguity; employs carrier phase differential positioning, using the corrected carrier phase observations, pseudorange observations, and precise ephemeris parameters as inputs, to establish a high-precision space observation equation and solve for the three-dimensional position coordinates of receiver 10; completes the fixed resolution of carrier phase integer ambiguity through phase smoothing and ambiguity search algorithms to eliminate ambiguity errors, and then performs time smoothing filtering on continuous centimeter-level positioning results to improve positioning stability; finally, transmits the calculated centimeter-level high-precision position, velocity, and time information to the positioning information output module.

[0058] The navigation device provided in this embodiment will be described in detail below, taking a surveying and monitoring scenario as an example: After the BeiDou receiver 10 for surveying is powered on, the autonomous time system 101 immediately starts up, performs blind acquisition and tracking of the BeiDou B1I public frequency points, completes meter-level basic positioning through pseudorange observation value calculation, and continuously outputs accurate BeiDou absolute timestamps; the host computer 20 obtains microsecond-level accurate time synchronization information through the BeiDou ground time synchronization base station and transmits it to the receiver 10, and the auxiliary time system 102 obtains external time synchronization information and determines that the time synchronization information is valid.

[0059] The auxiliary time system 102 then updates the local time reference with the external time information, calculates the prior acquisition parameters of the BeiDou B3I licensed frequency point and configures the radio frequency front end, completes the coherent acquisition and fine tracking of the B3I licensed signal, extracts the carrier phase observation value and precise ephemeris parameters, and completes the carrier phase integer ambiguity fixation after high-precision error correction and carrier phase differential positioning calculation, thus obtaining centimeter-level high-precision positioning results; the receiver 10 synchronously outputs dual-frequency point information of meter-level basic positioning and centimeter-level high-precision positioning according to a calculation period of 10Hz.

[0060] The surveying and monitoring scenario is a professional high-precision requirement scenario. The host computer 20 is preset to force the selection of high-precision positioning results, so the centimeter-level positioning results are directly used as the core data for surveying and mapping operations. If the high-precision results output by the auxiliary system show abnormalities such as position jumps or accuracy decay due to environmental factors such as tall buildings blocking the site or electromagnetic interference, the host computer 20 will immediately and automatically switch to the meter-level basic positioning results of the autonomous time system 101 to ensure that the position monitoring of the surveying equipment is uninterrupted. After the site environment improves and the high-precision positioning results stabilize, it will automatically switch back to the centimeter-level positioning results. If the operator needs to debug the equipment, he / she can manually switch to the basic positioning results through the manual entry of the host computer 20 to reduce the power consumption of the equipment. After debugging, he / she will switch back to the high-precision results.

[0061] If the timing information from the host computer 20 subsequently deviates significantly due to a base station malfunction, the auxiliary time system 102 determines that the timing is invalid or has a deviation and automatically stops working. At this time, the receiver 10 only outputs meter-level basic positioning information, which the host computer 20 directly receives as the final result, ensuring that the surveying work is not interrupted. When the base station malfunction is repaired and the host computer 20 resumes effective timing, the auxiliary time system 102 can be quickly restarted, the receiver 10 resumes dual-frequency point information output, and the host computer 20 automatically switches back to centimeter-level high-precision positioning results.

[0062] Unlike the single-system positioning mode of common satellite navigation receivers, this embodiment adopts a dual-time system positioning mode. Combining the technical characteristics of BeiDou's public and authorized signals, through independent benchmark design, precise timing judgment mechanism, flexible mode switching, and intelligent result selection logic of the host computer, it not only provides a backup guarantee for positioning function but also meets the positioning accuracy requirements of different scenarios. At the same time, it completely avoids the problem of receiver 10's normal positioning being affected by external timing deviations, greatly improving the effectiveness, stability, and adaptability of satellite navigation receiver 10's positioning. It can be widely used in various terminal receiver products of the BeiDou navigation system.

[0063] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A navigation device based on a dual-time system of a satellite navigation receiver, characterized in that, The navigation device includes a receiver and a host computer, and the receiver includes an autonomous time system and an auxiliary time system; The autonomous time system is used to capture publicly available BeiDou signals, extract a first timestamp from the publicly available BeiDou signals, and parse the publicly available BeiDou signals to obtain first positioning information. The auxiliary time system is used to acquire external time information, capture BeiDou authorization signals based on the external time information, and parse the BeiDou authorization signals to obtain second positioning information. The host computer is used to perform navigation based on the first positioning information, or, if the second positioning information exists, to perform navigation based on the first positioning information and / or the second positioning information.

2. The navigation device according to claim 1, characterized in that, The receiver is used to output first positioning information or second positioning information to the host computer at a preset period.

3. The navigation device according to claim 1, characterized in that, The auxiliary time system is used to obtain external time synchronization information from the BeiDou ground time synchronization base station through the host computer.

4. The navigation device according to claim 1, characterized in that, The host computer is used to select either the first positioning information or the second positioning information for navigation based on preset navigation scenario information when the second positioning information is available.

5. The navigation device according to claim 1, characterized in that, The host computer is used to perform navigation by fusing the first positioning information and the second positioning information when the second positioning information is available.

6. The navigation device according to claim 1, characterized in that, The host computer is used to select either the first positioning information or the second positioning information for navigation in response to a manual instruction when the second positioning information is available.

7. The navigation device according to claim 1, characterized in that, The autonomous time system is used to analyze the publicly available BeiDou signals based on the least squares method to obtain the first positioning information.

8. The navigation device according to claim 7, characterized in that, The auxiliary time system is used to analyze the BeiDou authorized signal based on the carrier phase differential positioning method to obtain the second positioning information.

9. The navigation device according to claim 1, characterized in that, The first positioning information and the second positioning information respectively include location information, time information and speed information.

10. The navigation device according to claim 1, characterized in that, The auxiliary time system captures the BeiDou licensed signal based on external time information, including: updating the local time based on the BeiDou timestamp in the external time information to establish a local BeiDou time reference; calculating the prior acquisition parameters of the BeiDou licensed signal based on the local BeiDou time reference; and performing coherent acquisition of the BeiDou licensed signal based on the prior acquisition parameters.

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