Time mutual verification method and system of satellite navigation receiver

Abstract

This invention discloses a time cross-verification method and system for a satellite navigation receiver. The method includes: acquiring a pre-installed ephemeris using the satellite navigation receiver, the pre-installed ephemeris including an ephemeris reference time; acquiring at least one frame of pre-timing information using the satellite navigation receiver, the pre-timing information including a timing time; performing time cross-verification between the timing time and the ephemeris reference time using the satellite navigation receiver; if the time cross-verification fails, outputting the time cross-verification result using the response frame corresponding to the pre-installed ephemeris. This invention uses the satellite navigation receiver to cross-verify the received pre-installed ephemeris time with the timing time to determine the correctness of the timing time and provides a corresponding response; it improves the timing time resolution capability and operational reliability of the product; simplifies the reliability judgment of the received time by the satellite navigation receiver; the time cross-verification method is reliable and stable, and has certain promotional value.

Description

Technical Field

[0001] This invention relates to the field of satellite navigation. More specifically, it relates to a time cross-checking method and system for a satellite navigation receiver. Background Technology

[0002] Satellite navigation receivers are widely used in various products, providing stable position, velocity, and other positioning information in a timely manner. Currently, receivers compatible with the BeiDou satellite navigation system generally use BeiDou satellite signals for positioning. This requires the system to provide the receiver with accurate BeiDou time so that the receiver can quickly acquire and track the BeiDou signal. Since the receiver itself does not have a reference time, it cannot determine the accuracy of the system's time synchronization. If the time synchronization is incorrect, the receiver will be unable to complete acquisition, tracking, and positioning normally. Therefore, it is necessary to use ephemeris information to determine the accuracy of the time synchronization, thereby eliminating the possibility of the receiver failing to locate due to incorrect time synchronization. Summary of the Invention

[0003] The purpose of this invention is to provide a time cross-checking method and system for satellite navigation receivers to solve at least one of the problems existing in the prior art.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: The first aspect of this invention provides a time cross-checking method for a satellite navigation receiver, the method comprising: Use a satellite navigation receiver to obtain pre-installed ephemeris, which includes ephemeris reference time; Use a satellite navigation receiver to acquire at least one frame of pre-timing information sent by the host computer. The pre-timing information includes the timing information. Use a satellite navigation receiver to perform time cross-checking between the time synchronization time and the ephemeris reference time; If the time cross-check fails, the satellite navigation receiver will output the time cross-check result through the response frame corresponding to the pre-installed ephemeris.

[0005] Optionally, the method further includes: If the time cross-verification passes, the satellite navigation receiver will be used to track satellite signals and perform positioning calculations based on the synchronized time.

[0006] Optionally, the step of using a satellite navigation receiver to perform time cross-checking between the timing time and the ephemeris reference time includes: Determine whether the time deviation between the time of the time transmission and the ephemeris reference time is within the first preset range; Determine whether the time of the announcement is within the range of the ephemeris reference time.

[0007] Optionally, determining whether the time deviation between the time of the time synchronization and the ephemeris reference time is within a first preset range includes: Convert the time synchronization time to satellite time; Determine whether the satellite time falls within the first preset range from half an hour before the hour to half an hour after the hour in the ephemeris reference time; If the satellite time is not within the first preset range, the time cross-verification fails.

[0008] Optionally, determining whether the time of synchronization is within the range of the ephemeris reference time includes: Determine whether the satellite time is earlier than the ephemeris effective time in the ephemeris reference time; If it is earlier, the time cross-validation failed; Or determine whether the satellite time is later than the ephemeris failure time in the ephemeris reference time; If it is later than that, the time cross-validation failed.

[0009] Optionally, before using a satellite navigation receiver to perform time cross-checking on the time synchronization time and the ephemeris reference time, the method further includes: performing a self-check on the time synchronization time and a self-check on the ephemeris reference time.

[0010] Optionally, the self-check of the time synchronization includes: Determine whether the week number in the time synchronization is within the second preset range; If it is not within the second preset range, the self-test will fail; Determine whether the value of the second within the week in the time synchronization is within the third preset range; If it is not within the third preset range, the self-test will fail.

[0011] Optionally, the self-check of the ephemeris reference time includes: Determine whether the week number in the ephemeris reference time is within the fourth preset range; If it is not within the fourth preset range, the self-test will fail; Determine whether the value of the second within the week in the ephemeris reference time is within the fifth preset range; If it is not within the fifth preset range, the self-test will fail.

[0012] Optionally, the ephemeris parameters of the pre-installed ephemeris are updated every hour, and the pre-installed ephemeris is updated at the top of the hour.

[0013] A second aspect of the present invention provides a time cross-checking system for a satellite navigation receiver, the system comprising: The host computer is used to send the pre-installed ephemeris so that the satellite navigation receiver can obtain the pre-installed ephemeris, which includes the ephemeris reference time. The host computer is also used to send at least one frame of pre-timing information so that the satellite navigation receiver can obtain at least three frames of pre-timing information, including the timing information; Satellite navigation receivers are used to perform time cross-checking between time synchronization time and ephemeris reference time; The satellite navigation receiver is also used to output the time cross-check result to the host computer when the time cross-check fails, by using the response frame corresponding to the pre-installed ephemeris.

[0014] The beneficial effects of this invention are as follows: The technical solution described in this invention provides a method for a satellite navigation receiver to verify the correctness of the time synchronization by cross-checking the pre-installed ephemeris time with the synchronized time. This invention determines the correctness of the time synchronization by cross-checking the received pre-installed ephemeris time with the synchronized time and provides a corresponding response. This invention improves the time synchronization resolution capability and operational reliability of the product. This invention simplifies the reliability judgment of the received time by the satellite navigation receiver. The time cross-checking method of this invention is reliable and stable in operation and has certain promotional value. Attached Figure Description

[0015] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0016] Figure 1 A flowchart illustrating the time cross-verification method for satellite navigation receivers provided in an embodiment of the present invention is shown. Detailed Implementation

[0017] 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.

[0018] Satellite navigation receivers are widely used in various products, providing stable position, velocity, and other positioning information in a timely manner. Currently, receivers compatible with the BeiDou satellite navigation system generally use BeiDou satellite signals for positioning. This requires the system to provide the receiver with accurate BeiDou time so that the receiver can quickly acquire and track the BeiDou signal. Since the receiver itself does not have a reference time, it cannot determine the accuracy of the system's time synchronization. If the time synchronization is incorrect, the receiver will be unable to complete acquisition, tracking, and positioning normally. Therefore, it is necessary to use ephemeris information to determine the accuracy of the time synchronization, thereby eliminating the possibility of the receiver failing to locate due to incorrect time synchronization.

[0019] Satellite navigation receivers using the BeiDou Navigation Satellite System require external time synchronization to achieve positioning functionality. To prevent gross errors in the timing information that could cause the receiver to fail to locate or to lose positioning functionality before a future time due to the internal authorized chip being set to a future time, software processing safeguards are added, with the receiver's internal software evaluating the timing results.

[0020] In view of this, such as Figure 1 As shown, one embodiment of the present invention provides a time mutual verification method for a satellite navigation receiver. The method includes: acquiring a pre-installed ephemeris using the satellite navigation receiver, the pre-installed ephemeris including an ephemeris reference time; acquiring at least one frame of pre-timing information sent by a host computer using the satellite navigation receiver, the pre-timing information including a timing time; performing time mutual verification between the timing time and the ephemeris reference time using the satellite navigation receiver; if the time mutual verification fails, outputting the time mutual verification result using the response frame corresponding to the pre-installed ephemeris using the satellite navigation receiver.

[0021] In a specific example, the pre-installed ephemeris time is the ephemeris reference time. In order to shorten the positioning time of the satellite navigation receiver, the system can pre-install the ephemeris information of the currently visible satellites after power-on. The ephemeris information of a single satellite includes the ephemeris reference time parameter. The update cycle of the ephemeris parameter is 1 hour, and it is updated on the hour in BeiDou time. The ephemeris reference time parameter takes the hourly time.

[0022] In a specific example, the timing information is the accurate time provided by the system to the satellite navigation receiver for satellite acquisition, tracking, and positioning. It consists of the BeiDou cycle number, the second within the BeiDou cycle, and the host computer frame number.

[0023] In a specific example, the normal interaction process between the system and the satellite navigation receiver is as follows: the system powers on, pre-installs ephemeris data on the satellite navigation receiver, sends auxiliary data including time synchronization to the satellite navigation receiver, and the satellite navigation receiver enters the acquisition and positioning process and uses the synchronized time for signal tracking and positioning. The design of this invention adds an interaction process between the system's host computer and the satellite navigation receiver to the normal process. After time synchronization with the ground, three additional frames of information exchange with the satellite navigation receiver are added, i.e., three additional frames of pre-synchronization. The satellite navigation receiver internally verifies the time synchronization information and the time of the pre-installed ephemeris. If any parameter in the time synchronization time or the time parameter in the pre-installed ephemeris is incorrect, the time is deemed invalid.

[0024] In a specific example, after the internal software of the satellite navigation receiver judges the timing result, it transmits the time cross-check result through the pre-installed ephemeris response frame, that is, the response pre-installed ephemeris value is invalid, indicating to the system that the reliability of the time (timing time or ephemeris time) received by the receiver at this time is questionable.

[0025] In one specific example, the invention is used on a satellite navigation receiver that uses signals from the BD3 satellite navigation system for positioning.

[0026] In a specific example, the system's host computer sends three frames of pre-timing information to the satellite navigation receiver.

[0027] In a specific example, when the current time is determined to be invalid, the satellite navigation receiver reports that the pre-installed ephemeris value is invalid in the response frame, in order to indicate to the system host computer that the reliability of the currently received time is questionable.

[0028] In a specific example, the satellite navigation receiver is a BeiDou-3 satellite navigation receiver, which performs positioning calculations based on signals from the BeiDou-3 satellite navigation system.

[0029] In a specific example, the satellite navigation receiver time mutual verification method is applied to a satellite navigation system that includes a system host computer and a satellite navigation receiver. The system host computer sends a pre-installed ephemeris and provides a time synchronization to the satellite navigation receiver to assist it in acquiring and positioning satellite signals. After completing ground time synchronization, the system host computer sends at least one frame of pre-time synchronization information carrying the time synchronization to the satellite navigation receiver. The satellite navigation receiver performs mutual verification between the received time synchronization and the ephemeris reference time contained in the pre-installed ephemeris. If any parameter in the time synchronization or the ephemeris reference time is incorrect, the current time is deemed invalid. The satellite navigation receiver outputs the time mutual verification result to the system host computer through the response frame corresponding to the pre-installed ephemeris.

[0030] The technical solution described in this invention provides a method for a satellite navigation receiver to verify the correctness of the time synchronization by cross-checking the pre-installed ephemeris time with the synchronized time. This invention determines the correctness of the time synchronization by cross-checking the received pre-installed ephemeris time with the synchronized time and provides a corresponding response. This invention improves the time synchronization resolution capability and operational reliability of the product. This invention simplifies the reliability judgment of the received time by the satellite navigation receiver. The time cross-checking method of this invention is reliable and stable in operation and has certain promotional value.

[0031] In one possible implementation, the method further includes: if the time cross-verification passes, then using a satellite navigation receiver to perform satellite signal tracking and positioning calculation based on the time synchronization.

[0032] This embodiment only starts satellite signal tracking and positioning calculation after the time cross-verification is successful. This can avoid problems such as satellite acquisition failure and positioning calculation abnormality caused by incorrect time synchronization from the source, reduce the overhead of invalid signal acquisition calculation of the receiver, and improve the success rate of the first positioning. At the same time, it can prevent the internal authorized chip from failing prematurely due to incorrect future time setting, and ensure the stable operation of the receiver.

[0033] In one possible implementation, the step of using a satellite navigation receiver to perform time cross-checking between the time synchronization time and the ephemeris reference time includes: determining whether the time deviation between the time synchronization time and the ephemeris reference time is within a first preset range; and determining whether the time synchronization time is within the range of the ephemeris reference time.

[0034] In a specific example, the timing information includes the BeiDou cycle number, the second within the BeiDou cycle, and the host computer frame number.

[0035] In a specific example, the essence of time mutual verification is the mutual verification of two independent time sources. The first independent time source is the pre-installed ephemeris time, i.e., the ephemeris reference time. After the system is powered on, it pre-installs the ephemeris data of currently visible satellites into the receiver. The ephemeris of a single satellite contains ephemeris reference time parameters. The BeiDou ephemeris parameter update cycle is 1 hour, and it is updated on the hour of BeiDou time. Therefore, the ephemeris reference time is fixed at the hour of BeiDou time, which is the time anchor point carried by the ephemeris itself. The second independent time source is the system time synchronization time. The host computer of the system provides the receiver with the reference time for satellite acquisition, tracking and positioning. It consists of three parts: the BeiDou week number, the second within the BeiDou week, and the host computer frame number. It is the input time for the receiver to work normally.

[0036] In a specific example, this embodiment adds a pre-timing interaction and internal verification step to the conventional pre-installation ephemeris, timing, and positioning process. The complete process includes the system's host computer completing ground-based time alignment and calibrating its own time reference; the system pre-installing ephemeris data of currently visible satellites into the satellite navigation receiver; the added verification pre-step involves the system sending three frames of pre-timing information to the receiver, carrying complete timing parameters; the receiver's internal software initiating cross-verification logic to cross-verify the timing time with the ephemeris reference time of the pre-installed ephemeris; after verification, the receiver feedback the verification result to the system via an ephemeris response frame; only when the verification passes does the receiver formally enter the satellite acquisition and positioning process, using the timing time to perform signal tracking and positioning calculations.

[0037] In a specific example, the receiver uses a logic that invalidates the entire time if any abnormality occurs. It also checks the rationality and time consistency of the two parameters, the time synchronization time and the ephemeris reference time. If either of the two time parameters is incorrect (e.g., the time deviation exceeds the reasonable range, the format is abnormal, or the ephemeris validity period is exceeded), the current time is determined to be invalid. Only when both time sources are normal and the time matching conforms to the ephemeris validity period logic is the time determined to be valid.

[0038] In a specific example, the verification result is sent back to the host computer of the system via a response frame with a pre-installed ephemeris. If the time is determined to be invalid, the response frame indicates that the pre-installed ephemeris value is invalid, indicating to the system that the reliability of the currently received time (e.g., the time synchronization time or ephemeris time) is questionable, triggering abnormal handling on the system side (e.g., re-sending the ephemeris or re-synchronizing the time). If the time is determined to be valid, the receiver normally starts the satellite acquisition, tracking and positioning process, and uses the time synchronization time to complete the subsequent positioning work.

[0039] This embodiment employs a dual cross-verification logic of time deviation threshold verification and time validity period range verification. It cross-verifies the time synchronization time and ephemeris reference time from two dimensions: the degree of numerical deviation and the timing logic matching. This can identify gross errors in time amplitude and detect logical misalignments in the time dimension, avoiding omissions and misjudgments by a single verification rule, and significantly improving the accuracy and reliability of the time cross-verification results.

[0040] In one possible implementation, determining whether the time deviation between the time synchronization time and the ephemeris reference time is within a first preset range includes: converting the time synchronization time into a satellite time; determining whether the satellite time is within a first preset range from half an hour before the hour to half an hour after the hour in the ephemeris reference time; if the satellite time is not within the first preset range, then the time cross-verification fails.

[0041] In a specific example, the time deviation threshold verification involves converting the time synchronization time into a unified absolute BeiDou time and comparing it with the ephemeris reference time. The time deviation must fall within a preset threshold.

[0042] Furthermore, considering the characteristic of the ephemeris being updated every hour, the threshold is set to ±1800 seconds, or ±30 minutes. This means that the time must fall within half an hour before or after the corresponding ephemeris reference hour. If the deviation exceeds the threshold, it indicates that at least one of the two time sources is inaccurate, and the verification fails.

[0043] This embodiment converts the time synchronization time into a standard satellite time and uses half an hour before and after the ephemeris reference time as the deviation judgment threshold. This is precisely adapted to the characteristic of BeiDou ephemeris updating every hour. The threshold setting fits the actual effective window of the ephemeris, which can not only sensitively identify abnormal deviations in the time synchronization time, but also avoid misjudging normal time fluctuations as errors, thus ensuring a balance between verification sensitivity and accuracy.

[0044] In one possible implementation, determining whether the time synchronization time is within the range of the ephemeris reference time includes: determining whether the satellite time is earlier than the ephemeris effective time in the ephemeris reference time; if it is earlier, then the time cross-verification fails; or determining whether the satellite time is later than the ephemeris invalid time in the ephemeris reference time; if it is later, then the time cross-verification fails.

[0045] In a specific example, the time logic matching verification includes ensuring that the time synchronization time falls within the valid coverage period of the currently pre-installed ephemeris, and that there are no logical contradictions such as the time synchronization time being earlier than the ephemeris's effective time or later than the ephemeris's invalid time, so as to ensure that the ephemeris and the time synchronization time belong to the same valid time window.

[0046] This embodiment verifies the sequential relationship between the time synchronization time and the ephemeris's effective and ineffective times. This can accurately eliminate abnormal scenarios where the time synchronization time falls outside the effective ephemeris period, ensuring that the time synchronization time and the ephemeris parameters used correspond one-to-one in the time dimension during subsequent positioning calculations. This avoids positioning calculation deviations or even failures caused by expired or ineffective ephemeris.

[0047] In one possible implementation, before performing time cross-checking on the time synchronization time and the ephemeris reference time using a satellite navigation receiver, the method further includes: performing a self-check on the time synchronization time and a self-check on the ephemeris reference time.

[0048] In a specific example, the method also includes a single time source self-check rule to determine whether a single parameter is incorrect. This is a prerequisite for time mutual verification, checking the legality and rationality of the two time sources themselves. If a single parameter self-check fails, the entire system is deemed invalid.

[0049] Before cross-checking the two time sources, this embodiment performs self-checks on the time synchronization time and ephemeris reference time, forming a two-level verification system of single-source self-check and dual-source cross-check. This can filter out explicit errors such as format abnormalities and numerical overflows in advance, reducing the computational load of subsequent cross-checks. At the same time, it covers different types of time anomalies in layers, improving the comprehensiveness and execution efficiency of the verification.

[0050] In one possible implementation, the self-check of the time synchronization includes: determining whether the week number in the time synchronization is within a second preset range; if it is not within the second preset range, the self-check fails; determining whether the second within the week in the time synchronization is within a third preset range; if it is not within the third preset range, the self-check fails.

[0051] In a specific example, the timing information is composed of the BeiDou week number, the seconds within the BeiDou week, and the host computer frame number. The timing information self-check items include format legality, ensuring that the BeiDou week number and the seconds within the week are within the legal range, and that the host computer frame number conforms to the format and range agreed upon in the protocol, without gross errors; the timing information self-check items also include time rationality, ensuring that the timing information is not extremely abnormal, such as far exceeding the operating time range of the BeiDou system, avoiding the insertion of incorrect future or past times, and preventing the internal authorized chips from malfunctioning due to incorrect future times.

[0052] In a specific example, the BeiDou week number is the integer count of BeiDou time, corresponding to the continuous time measurement system of the BeiDou system. The BeiDou week number self-check includes a numerical attribute check; it must be an unsigned integer. Negative values, decimals, or non-numerical garbled characters are directly judged as format errors. The BeiDou week number self-check includes a value range check; it follows the BeiDou system standard encoding, with a valid range of 0~1023. Values ​​outside this range are directly judged as invalid formats. The BeiDou week number self-check includes a time magnitude reasonableness check; the deviation between the time-provided week number and the current actual BeiDou week number must not exceed ±52 weeks. Excessive deviation indicates a gross error in the time-provided week number. The BeiDou week number self-check includes an ephemeris matching reasonableness check; the deviation between the time-provided week number and the week number of the pre-installed ephemeris reference time must not exceed ±1 week. Because the ephemeris validity period is only a few hours before and after the reference time, cross-week scenarios are extremely rare; a deviation exceeding 1 week indicates an abnormal time parameter.

[0053] In a specific example, the week-end second is the second-level count of the current time within this week, and it is the core time component of BeiDou time synchronization. The week-end second self-check includes a value range check; the total duration of a week is 7 × 24 × 3600 = 604800 seconds, therefore the valid range is 0~604800. The week-end second self-check also includes an absolute illegal case check: if the week-end second is negative, ≥604800, or is a non-numerical garbled character, the format is directly judged as incorrect. The week-end second self-check also includes an inter-frame continuity check; for the 3 consecutive frames of pre-synchronization data in this scheme, the week-end second of adjacent frames should monotonically increase, and the increment should match the frame transmission interval; if time rollback or excessive jump amplitude occurs, the time synchronization data is judged as abnormal.

[0054] In a specific example, the host computer frame number is a frame identifier in the communication protocol between the system and the receiver, used to distinguish different interactive data such as pre-time synchronization frames and ephemeris frames. The host computer frame number self-check includes format attribute verification; it must be an unsigned integer as defined in the protocol, such as 8 bits or 16 bits. Negative values, non-integer values, or values ​​exceeding the protocol's bit width range are directly considered format errors. The host computer frame number self-check also includes type matching verification; the frame number of the pre-time synchronization frame must fall within the protocol-defined numbering range for time synchronization data frames, clearly distinguishing it from the numbering ranges of ephemeris frames and command frames. If it falls into other frame type ranges, the frame type is directly considered mismatched and the parameters invalid. The host computer frame number self-check also includes continuity verification. In this scheme, the three pre-time synchronization frames are sent consecutively, and the frame numbers should conform to the protocol's incrementing rules, such as N, N+1, and N+2 sequentially. Skipped numbers, duplicate numbers, or reverse order are considered transmission anomalies and the time synchronization data is unreliable. The host computer frame number self-check includes range rationality check. The frame number must fall within the valid working range agreed upon in the protocol and must not contain error codes or abnormal code values ​​reserved in the protocol.

[0055] This embodiment sets value ranges for the BeiDou week number and the second component within the week for self-checking, which can quickly identify format errors such as week number exceeding the limit and second overflow within the week. It eliminates problems such as disordered data transmission, parsing failure, and gross errors from the data layer, ensuring the legality of the basic format of the time synchronization and providing an effective verification object for subsequent mutual verification.

[0056] In one possible implementation, the self-check of the ephemeris reference time includes: determining whether the week number in the ephemeris reference time is within a fourth preset range; if it is not within the fourth preset range, the self-check fails; determining whether the second within the week in the ephemeris reference time is within a fifth preset range; if it is not within the fifth preset range, the self-check fails.

[0057] In a specific example, the ephemeris reference time includes ephemeris parameters updated every hour, BeiDou time updated on the hour, and the ephemeris reference time rounded to the hour. The ephemeris reference time self-check items include format validity, i.e., the ephemeris reference time is in standard BeiDou time format, i.e., BeiDou week number, seconds within the week, with the seconds within the week ranging from 0 to 604800, without overflow, garbled characters, or illegal values; the ephemeris reference time self-check items include hour attribute verification, the seconds within the week of the ephemeris reference time must be an integer multiple of 3600, i.e., corresponding to the BeiDou time on the hour, i.e., 3600×1~3600×N1, where N1 is a positive integer greater than 1, if not conforming, the ephemeris time parameter is judged to be incorrect; the ephemeris reference time self-check items include validity period rationality, the ephemeris reference time has no obvious expiration or extreme future time anomalies, and matches the 1-hour ephemeris update cycle.

[0058] This embodiment performs a self-check on the range of values ​​for the BeiDou week number and the second component within the week of the ephemeris reference time. This can identify time parameter anomalies caused by corrupted ephemeris data or parsing errors in advance, ensuring that the ephemeris reference time itself, which serves as the mutual verification benchmark, is in a valid format and has valid values. This avoids distortion of the entire mutual verification result due to errors in the verification benchmark itself, thus ensuring the reliability of the verification benchmark.

[0059] In one possible implementation, the ephemeris parameters of the pre-installed ephemeris are updated every hour, and the pre-installed ephemeris is updated at the top of the hour.

[0060] In a specific example, the ephemeris parameters of the pre-installed ephemeris are updated every hour and are updated at the hour of BeiDou time. The ephemeris reference time is the hour of BeiDou time.

[0061] This embodiment clearly defines the time characteristics of the pre-installed ephemeris being updated every hour and on the hour, providing a clear time reference for setting the deviation threshold and determining the validity period of the ephemeris in mutual verification. This ensures that the entire mutual verification logic is compatible with the actual update mechanism of the BeiDou system ephemeris, guaranteeing the engineering feasibility and rationality of the verification rules.

[0062] Another embodiment of the present invention provides a time mutual verification system for a satellite navigation receiver. The system includes: a host computer, configured to send a pre-installed ephemeris to enable the satellite navigation receiver to acquire the pre-installed ephemeris, the pre-installed ephemeris including an ephemeris reference time; the host computer is further configured to send at least three frames of pre-timing information to enable the satellite navigation receiver to acquire at least one frame of pre-timing information, the pre-timing information including a timing time; the satellite navigation receiver is configured to perform time mutual verification between the timing time and the ephemeris reference time; and the satellite navigation receiver is further configured to output the time mutual verification result to the host computer via a response frame corresponding to the pre-installed ephemeris if the time mutual verification fails.

[0063] The technical solution described in this invention provides a method for a satellite navigation receiver to verify the correctness of the time synchronization by cross-checking the pre-installed ephemeris time with the synchronized time. This invention determines the correctness of the time synchronization by cross-checking the received pre-installed ephemeris time with the synchronized time and provides a corresponding response. This invention improves the time synchronization resolution capability and operational reliability of the product. This invention simplifies the reliability judgment of the received time by the satellite navigation receiver. The time cross-checking method of this invention is reliable and stable in operation and has certain promotional value.

[0064] 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.

[0065] 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.

[0066] 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 time cross-checking method for a satellite navigation receiver, characterized in that, The method includes: Use a satellite navigation receiver to obtain a pre-installed ephemeris, which includes ephemeris reference time; Use a satellite navigation receiver to acquire at least one frame of pre-timing information sent by the host computer. The pre-timing information includes the timing information. Use a satellite navigation receiver to perform time cross-checking between the time synchronization time and the ephemeris reference time; If the time cross-check fails, the satellite navigation receiver will output the time cross-check result through the response frame corresponding to the pre-installed ephemeris.

2. The time mutual verification method for a satellite navigation receiver according to claim 1, characterized in that, The method also includes: If the time cross-verification passes, the satellite navigation receiver will be used to track satellite signals and perform positioning calculations based on the synchronized time.

3. The time mutual verification method for a satellite navigation receiver according to claim 1, characterized in that, The step of using a satellite navigation receiver to perform time cross-checking between the time synchronization time and the ephemeris reference time includes: Determine whether the time deviation between the time of the time transmission and the ephemeris reference time is within the first preset range; Determine whether the time of the announcement is within the range of the ephemeris reference time.

4. The time mutual verification method for a satellite navigation receiver according to claim 3, characterized in that, The determination of whether the time deviation between the time of the time service and the ephemeris reference time is within a first preset range includes: Convert the time synchronization time to satellite time; Determine whether the satellite time falls within the first preset range from half an hour before the hour to half an hour after the hour in the ephemeris reference time; If the satellite time is not within the first preset range, the time cross-verification fails.

5. The time mutual verification method for a satellite navigation receiver according to claim 3, characterized in that, The determination of whether the time of service is within the range of ephemeris reference time includes: Determine whether the satellite time is earlier than the ephemeris effective time in the ephemeris reference time; If it is earlier, the time cross-validation failed; Or determine whether the satellite time is later than the ephemeris failure time in the ephemeris reference time; If it is later than that, the time cross-validation failed.

6. The time mutual verification method for a satellite navigation receiver according to claim 1, characterized in that, Before using a satellite navigation receiver to perform time cross-checking between the time synchronization time and the ephemeris reference time, the method also includes: performing a self-check on the time synchronization time and a self-check on the ephemeris reference time.

7. The time mutual verification method for a satellite navigation receiver according to claim 6, characterized in that, The self-check of the time synchronization includes: Determine whether the week number in the time synchronization is within the second preset range; If it is not within the second preset range, the self-test will fail; Determine whether the value of the second within the week in the time synchronization is within the third preset range; If it is not within the third preset range, the self-test will fail.

8. The time mutual verification method for a satellite navigation receiver according to claim 6, characterized in that, The self-check of the ephemeris reference time includes: Determine whether the week number in the ephemeris reference time is within the fourth preset range; If it is not within the fourth preset range, the self-test will fail; Determine whether the value of the second within the week in the ephemeris reference time is within the fifth preset range; If it is not within the fifth preset range, the self-test will fail.

9. The time mutual verification method for a satellite navigation receiver according to claim 1, characterized in that, The pre-installed ephemeris parameters are updated every hour, and the pre-installed ephemeris is updated on the hour.

10. A time cross-checking system for a satellite navigation receiver, characterized in that, The system includes: The host computer is used to send the pre-installed ephemeris so that the satellite navigation receiver can obtain the pre-installed ephemeris, which includes the ephemeris reference time. The host computer is also used to send at least one frame of pre-timing information so that the satellite navigation receiver can obtain at least three frames of pre-timing information, including the timing information; Satellite navigation receivers are used to perform time cross-checking between time synchronization time and ephemeris reference time; The satellite navigation receiver is also used to output the time cross-check result to the host computer when the time cross-check fails, by using the response frame corresponding to the pre-installed ephemeris.

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