A high-precision classification and grading time synchronization service method and device for dense forest environment

Abstract

The present invention discloses a high-precision hierarchical classification time synchronization service method and device suitable for complex environments in dense forests, and belongs to the field of time synchronization technology. The present invention provides time synchronization services for surrounding node devices through chip-level atomic clocks, satellite navigation receiving boards, processors, UWB ranging communication modules, and NTP timing service modules. In response to the problem of GNSS time service capability failure caused by severe obstruction of satellite navigation signals and severe multipath problems in dense forest environments, the present invention relies on prior conditions such as the precise knowledge of monitoring and surveillance deployment points and the inherent properties of the performance characteristics of the built-in chip atomic clocks in the equipment, and proposes technologies such as GNSS single-star timing, UWB / NTP time classification calibration, and online error compensation constrained by the prior information of the local atomic clock under known coordinates. It can provide different types of time services such as physical signal level, wired network level, and wireless information service level for different network user nodes such as monitoring and scheduling in dense forest environments.

Description

Technical Field

[0001] The present invention belongs to the field of time synchronization technology, and in particular refers to a high-precision hierarchical and classified time synchronization service method and equipment suitable for complex dense forest environments. It can meet the high-precision, hierarchical and classified differentiated time synchronization service needs of different network user nodes such as monitoring and scheduling in dense forest environments where satellite navigation signals are severely blocked and wired network infrastructure is difficult to deploy. Background Art

[0002] GNSS high-precision timing and NTP network timing technologies, as the core technical means of high-precision timing services, can provide high-precision time synchronization and timing services in open environments with a large number of visible satellites and in areas with well-deployed wired networks, respectively. However, in dense forest environments where satellite navigation signals are severely blocked and large-scale deployment of wired network infrastructure is difficult, how to solve the differentiated time synchronization service needs of different levels and forms of different network user equipment nodes in monitoring, collaborative processing, command and control, etc., is an important information support for multi-department collaboration and rapid handling of emergency tasks in dense forest environments.

[0003] High-precision GNSS timing and NTP network timing technologies have become the primary means of time synchronization. However, they are still not suitable for meeting the differentiated time synchronization service requirements of different network user device node levels and forms in dense forest environments where satellite navigation signals are severely blocked and large-scale deployment of wired network infrastructure is difficult. This is mainly reflected in the following aspects:

[0004] (1) GNSS timing equipment faces the problem of less than 4 satellites being observed and serious pseudo-range multipath problems in dense forest obstruction environments. At this time, GNSS-based timekeeping and positioning timing services are prone to failure defects.

[0005] (2) Large-scale deployment of wired networks in humid and dense forest environments presents obstacles, and the scope of traditional wired network timing is severely limited.

[0006] (3) In dense forest environments, different network user device nodes have different requirements for time synchronization accuracy.

[0007] In summary, current time synchronization methods generally ignore accumulated delay errors and do not effectively compensate for them. However, in dense forest environments, where satellite navigation signals are severely obstructed and large-scale deployment of wired network infrastructure is difficult, developing a high-precision, hierarchical, and classified time synchronization service approach for complex dense forest environments is crucial for achieving multi-departmental collaboration and rapidly handling emergency response tasks. This approach can meet the differentiated time synchronization service needs of different network user device nodes at different levels and in different forms. Summary of the Invention

[0008] In order to solve the problem that traditional time synchronization service methods are inefficient or even fail due to satellite navigation obstruction and serious cumulative errors in time transmission in complex environments such as dense forests, the present invention proposes a high-precision hierarchical and classified time synchronization service method and equipment suitable for complex environments such as dense forests. The method and equipment can provide different types of time services such as physical signal level, wired network level, and wireless information service level for different network user nodes such as monitoring and scheduling in dense forest environments.

[0009] The technical solution adopted in the present invention is:

[0010] A high-precision classification and grading time synchronization service method for dense forest environments is used to obtain time information through a single satellite and provide time synchronization services for surrounding node devices, including the following steps:

[0011] Capture and track GNSS satellite pseudorange and carrier phase observation data;

[0012] Based on the tracked and captured GNSS satellite pseudorange and carrier phase observation data, and according to the known coordinates of the deployment site and the prior clock error information of the local chip-level atomic clock, a GNSS observation value anomaly and multipath anomaly detection discriminant is designed to realize the identification of GNSS pseudorange observation value anomalies and multipath anomalies;

[0013] Construct a GNSS single-satellite time deviation estimation equation constrained by the prior clock error information of the local chip-level atomic clock. This enables estimation of the time deviation between the local chip-level atomic clock and GNSS time based on a single GNSS satellite in dense forest environments with severe pseudorange multipath.

[0014] Based on the time deviation between the local chip-level atomic clock and the GNSS time, a rule for distinguishing abnormalities in the local chip-level atomic clock time input signal is constructed;

[0015] Determine whether there are any anomalies between the time deviation between the local chip-level atomic clock and the GNSS and the GNSS 1PPS signal input. If the 1PPS signal input is normal, tame the local chip-level atomic clock time until it stabilizes.

[0016] Using the local chip-level atomic clock as the time and frequency reference source, it provides physical signal-level 1PPS, 10MHz, and TOD time services, and transmits 1PPS and TOD time and frequency information to the local processor via real-time interrupts of 1PPS events.

[0017] The local processor builds a time-frequency data error compensation model based on the cumulative counters of the previous and subsequent interrupt times to compensate for the time deviation caused by the inaccurate frequency of the local processor itself;

[0018] The local processor uses its own compensated TOD_S time as the time reference source. Based on the NTP network service protocol, it provides real-time two-way wired-level time services for monitoring and surveillance network nodes with wired connection capabilities within a short range of the deployment point through the NTP timing service module. In addition, it uses the UWB ranging communication module to carry TOD_S time information using UWB pulse signals as a carrier, providing one-way information-type wireless time synchronization services for node devices within a long range of the deployment point.

[0019] Furthermore, the GNSS observation value anomaly and multipath anomaly detection discriminant is:

[0020]

[0021] in:

[0022]

[0023] Where, represents the f-frequency pseudorange measurement value of the i-th GNSS satellite, C is the speed of light, I i and T i Represent the ionospheric and tropospheric delay information of the i-th GNSS satellite, δt i represents the satellite clock error of the i-th GNSS satellite, represents the pseudo-range code phase deviation of frequency f of the i-th GNSS satellite, r0 and r s Represent the known position of the deployment point and the GNSS satellite position vector respectively, represents the a priori clock error of the local chip-level atomic clock at time t, δ ρ is the threshold for judging abnormal GNSS satellite pseudorange measurements.

[0024] Furthermore, the GNSS single satellite time bias estimation equation constrained by the local chip-level atomic clock priori clock error information is:

[0025]

[0026] in, represents the f-frequency pseudorange measurement value of the i-th GNSS satellite, Represents the geometric distance between the coordinate deployment point and the i-th GNSS satellite, C is the speed of light, I i and T i Represent the ionospheric and tropospheric delay information of the i-th GNSS satellite, represents the carrier phase measurement value of frequency f of the i-th GNSS satellite, represents the pseudorange code phase deviation of frequency f of the i-th GNSS satellite, and represent the pseudorange noise and carrier phase noise of the observed frequency f of the i-th GNSS satellite, δt i represents the satellite clock error of the i-th GNSS satellite, represents the carrier phase ambiguity of the i-th GNSS satellite, δt(t) is the time deviation between the local chip-level atomic clock and the GNSS time at time t, represents the a priori clock error of the local chip-level atomic clock at time t, P δt is the prior weight of the prior observation equation.

[0027] Furthermore, the rule for determining abnormality of the local chip-level atomic clock time input signal is:

[0028]

[0029] in, represents the a priori clock error of the local chip-level atomic clock at time t, δt(t) is the time deviation between the local chip-level atomic clock and GNSS time at time t, δt(t0) is the time deviation between the local chip-level atomic clock and GNSS time at the previous time t0, ε δt is the threshold for judging abnormality of the chip-level atomic clock time-frequency signal input at time t.

[0030] Furthermore, the time-frequency data error compensation model is:

[0031]

[0032] in:

[0033]

[0034] Where deltaT is the time deviation caused by the inaccurate frequency of the local processor itself, N1 and N2 are the count values ​​of the cumulative counter when the interrupt is triggered by the 1PPS signal at the current moment and the previous moment, N tod The count value of the cumulative counter when the local processor completes TOD parsing and processor time calibration.

[0035] Furthermore, the local processor uses its own compensated TOD_S time as the time reference source. The specific compensation method is:

[0036] T tod_s =T tod +deltaT

[0037]

[0038] Among them, T tod and T tod_sare the TOD time information before and after compensation of the local processor, deltaT is the time deviation caused by the inaccurate frequency of the local processor itself, and T ntp Provides time information when providing NTP timing service to the local processor, N ntp The count value of the cumulative counter when providing NTP timing services to the local processor.

[0039] A high-precision, classified, and graded time synchronization service device for dense forest environments. It is used to obtain time information through a single satellite and provide time synchronization services to surrounding node devices. It includes a chip-level atomic clock, a satellite navigation receiver board, a processor, a UWB ranging communication module, and an NTP timing service module.

[0040] The satellite navigation receiving board is used to perform the following steps:

[0041] Capture and track GNSS satellite pseudorange and carrier phase observation data;

[0042] Based on the tracked and captured GNSS satellite pseudorange and carrier phase observation data, and according to the known coordinates of the deployment site and the prior clock error information of the chip-level atomic clock, a discriminant function for detecting GNSS observation value anomalies and multipath anomalies is designed to realize the identification of GNSS pseudorange observation value anomalies and multipath anomalies.

[0043] Construct a GNSS single-satellite time deviation estimation equation constrained by the chip-level atomic clock's a priori clock error information, and achieve estimation of the time deviation between the chip-level atomic clock and GNSS time based on a single GNSS satellite in dense forest environments with severe pseudorange multipath.

[0044] The chip-level atomic clock is used to perform the following steps:

[0045] Based on the time deviation between the chip-level atomic clock and GNSS time, an abnormal discrimination equation for the chip-level atomic clock time input signal is constructed;

[0046] Determine whether there are any anomalies between the chip-level atomic clock and GNSS time deviation and the GNSS 1PPS signal input. If the 1PPS signal input is normal, tame the local chip-level atomic clock time until it stabilizes.

[0047] Using the local chip-level atomic clock as the time and frequency reference source, it provides physical signal-level 1PPS, 10MHz, and TOD time services, and transmits 1PPS and TOD time and frequency information to the processor via real-time interrupts of 1PPS events.

[0048] The processor is configured to perform the following steps:

[0049] Based on the cumulative counters of the previous and next interrupt times, a time-frequency data error compensation model is constructed to compensate for the time deviation caused by the inaccurate frequency of the processor itself;

[0050] The processor uses its own compensated TOD_S time as the time reference source. Based on the NTP network service protocol, it provides real-time two-way wired-level time services for monitoring and surveillance network nodes with wired connection capabilities within a short range of the deployment point through the NTP timing service module. In addition, the UWB ranging communication module is used to carry TOD_S time information using UWB pulse signals, providing one-way information-type wireless time synchronization services for devices within a long range of the deployment point.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] 1. To address the problem of GNSS time service failure caused by severe obstruction and multipath problems of satellite navigation signals, the present invention relies on prior conditions such as the precise knowledge of monitoring deployment points in dense forest environments and the inherent properties of the performance characteristics of the atomic clock built into the device chip. It proposes technologies such as GNSS single-satellite timing, UWB / NTP time classification calibration and online error compensation under known coordinates, which are constrained by the prior information of the local atomic clock. These technologies can provide different types of time services such as physical signal level, wired network level and wireless information service level for different network user nodes such as monitoring and scheduling in dense forest environments.

[0053] 2. In view of the obstacles in deploying wired networks on a large scale in humid and dense forest environments, and the serious limitations on the range and accuracy of traditional wired network timing, the present invention designs a time-frequency reference compensation model for UWB wireless ranging and an NTP time-frequency data error compensation model, which meets the high-precision, hierarchical and differentiated time synchronization service requirements for different network user nodes such as monitoring and scheduling in dense forest environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 This is a schematic diagram of the principle of high-precision hierarchical and classified time synchronization service in an embodiment of the present invention. DETAILED DESCRIPTION

[0055] In order to better illustrate the purpose and advantages of the present invention, the technical solution of the present invention is further described below with reference to the accompanying drawings.

[0056] like Figure 1As shown, a high-precision hierarchical and classified time service device includes the following modules: an STM32 main processor, a UWB ranging module, an NTP timing service module, a chip-level atomic clock, and a satellite navigation receiver board. The satellite navigation receiver board receives satellite signals, tracks and captures carrier phase and pseudorange measurement data, and then performs processing on the satellite navigation receiver board, such as detecting and discriminating GNSS observation value anomalies and multipath anomalies, and providing single-satellite timing based on the local atomic clock's prior information constraints under known coordinates. Simultaneously, the chip-level atomic clock is tamed based on the state of the satellite navigation receiver board's input signal. Using the STM32 as the main processor, it performs comprehensive processing, including error compensation and time base compensation, and then provides time synchronization services at the physical signal level, bidirectional wired level, and unidirectional information level.

[0057] The specific steps for high-precision hierarchical classification time service are as follows:

[0058] (1) Deploy high-precision hierarchical and classified time service equipment and place it in dense forest rivers, forest paths, tall tree trunks and other places where at least one satellite can be observed. The equipment is used to provide time synchronization services for surrounding wired or wireless node devices.

[0059] (2) Based on the tracked and captured GNSS satellite pseudorange and carrier phase observation data information, and according to the known coordinates of the deployment site and the prior clock error information of the atomic clock built into the device chip, a GNSS observation value anomaly and multipath anomaly detection discriminant is designed to realize the identification of GNSS pseudorange observation value anomalies and multipath anomalies.

[0060] Among them, the discriminant formula for GNSS observation value anomaly and multipath anomaly detection is as follows:

[0061]

[0062]

[0063] in, represents the pseudorange measurement value of frequency f of GNSS satellite i, Represents the geometric distance between the deployment point and GNSS satellite i, I i and T i Represent the ionospheric and tropospheric delay information of GNSS satellite i, δt i represents the satellite clock error of GNSS satellite i, Represents the pseudo-range code phase deviation of GNSS satellite i frequency f, r0 and r s Represent the known position of the deployment point and the GNSS satellite position vector respectively, represents the a priori clock error of the atomic clock built into the device at time t, δ ρ is the threshold for judging abnormal GNSS satellite pseudorange measurements.

[0064] (3) Construct a GNSS single satellite time deviation estimation equation constrained by the chip atomic clock prior clock error information, so as to estimate the time deviation between the local internal chip-level atomic clock and GNSS time based on the GNSS single satellite.

[0065] The GNSS single satellite time bias estimation equation constrained by the chip atomic clock prior clock error information is as follows:

[0066]

[0067]

[0068]

[0069] in, represent the carrier phase measurement value of the observed GNSS satellite i at frequency f, and represent the pseudorange noise and carrier phase noise of the observed GNSS satellite i frequency f, δt i and δt represent the satellite clock error and receiver clock error of GNSS satellite i, respectively. represents the carrier phase ambiguity of GNSS satellite i, δt(t) is the time deviation between the local internal chip-level atomic clock and GNSS time at time t, P δt is the prior weight of the prior observation equation, and other symbols are consistent with the previous description.

[0070] (4) Based on the time deviation between the local internal chip-level atomic clock and the GNSS time, a criterion for judging the abnormality of the chip-level atomic clock time input signal is constructed:

[0071]

[0072] Among them, δt(t0) is the time deviation between the local internal chip-level atomic clock and GNSS time at the previous moment t0, ε δt is the threshold for judging abnormality of the chip-level atomic clock time-frequency signal input at time t.

[0073] (5) Based on the above judgment criteria, it is judged whether there is an abnormality between the local internal chip-level atomic clock and the GNSS time deviation and the GNSS 1PPS signal input. When it is determined that there is no abnormality in the input signal, the local internal chip atomic clock time is tamed until it is stable.

[0074] (6) Using the local internal chip atomic clock as the time and frequency reference source, it provides physical signal level 1PPS, 10MHz and TOD time and frequency service capabilities.

[0075] (7) Based on the 1PPS and TOD time-frequency information output by the internal chip atomic clock, the time is transmitted to the STM32 main processor in the form of a real-time interrupt of the 1PPS event. The main processor builds a time-frequency data error compensation model based on the cumulative counter of the previous and subsequent interrupt moments to compensate for the time deviation caused by the inaccurate frequency of the STM32 main processor itself. The main processor uses its own compensated TOD_S time as the time reference source and provides real-time two-way wired-level time services for monitoring and surveillance network nodes with wired connection capabilities within a short range of the deployment point based on the NTP network service protocol.

[0076] Among them, the time-frequency data error compensation model is as follows:

[0077]

[0078]

[0079] Where deltaT is the time deviation caused by the inaccurate frequency of the STM32 main processor itself, N1 and N2 are the count values ​​of the internal counter of the main controller when the interrupt is triggered by the 1PPS signal at the current moment and the previous moment, N tod The count value of the internal counter when the current main processor completes TOD parsing and main processor time calibration.

[0080] The main processor provides real-time, two-way, wired-level time services to monitoring and surveillance network nodes with wired connectivity within close proximity of the deployment point. Its own time compensation is implemented as follows:

[0081] T tod_s =T tod +deltaT

[0082]

[0083] Among them, T tod and T tod_s are the TOD time information before and after the main processor compensation, T ntp Time information when providing NTP timing service to the main processor, N ntp The count value of the internal counter when the main processor currently provides NTP timing service.

[0084] (8) Based on the compensated STM32 main processor time TOD_S as the time reference source, and using the UWB pulse signal as the carrier, by carrying the TOD_S time information, a one-way information type wireless time synchronization service is provided for devices within a long distance range of the deployment point.

[0085] After receiving the UWB wireless time synchronization information, each node device compensates for the time reference deviation introduced by the wireless transmission delay based on the time-frequency reference compensation model of UWB wireless ranging.

[0086] Among them, the UWB wireless ranging time-frequency reference compensation model is as follows:

[0087]

[0088] Among them, T uwb is the time information obtained after compensation of each node device, ρ uwb N is the distance measurement value between the time service device and each node device. uwb The time from when the UWB signal arrives at each device node to when it is parsed to T tod_s The counter value of the time information.

[0089] In summary, the present invention solves the problems of GNSS timing and positioning timing services facing failure when the number of satellite observations is less than 4 and there is severe pseudo-range multipath in dense forest environments where satellite navigation signals are severely blocked and wired network infrastructure is difficult to deploy, as well as the problem that the network timing range is limited due to obstacles in large-scale deployment of wired networks in humid and other dense forest environments. It greatly improves the availability and stability of high-precision time synchronization services in complex dense forest environments, and has important engineering practical application value for high-precision, hierarchical and classified differentiated time synchronization services for different network user nodes such as monitoring and scheduling in dense forest environments.

Claims

1. A high-precision classification and grading time synchronization service method for dense forest environment, characterized by: It is used to obtain time information through a single satellite and provide time synchronization services for surrounding node devices, including the following steps: Capture and track GNSS satellite pseudorange and carrier phase observation data; Based on the tracked and captured GNSS satellite pseudorange and carrier phase observation data, and according to the known coordinates of the deployment site and the prior clock error information of the local chip-level atomic clock, a GNSS observation value anomaly and multipath anomaly detection discriminant is designed to realize the identification of GNSS pseudorange observation value anomalies and multipath anomalies; Construct a GNSS single-satellite time deviation estimation equation constrained by the prior clock error information of the local chip-level atomic clock. This enables estimation of the time deviation between the local chip-level atomic clock and GNSS time based on a single GNSS satellite in dense forest environments with severe pseudorange multipath. Based on the time deviation between the local chip-level atomic clock and the GNSS time, a rule for distinguishing abnormalities in the local chip-level atomic clock time input signal is constructed; Determine whether there are any anomalies between the time deviation between the local chip-level atomic clock and the GNSS and the GNSS 1PPS signal input. If the 1PPS signal input is normal, tame the local chip-level atomic clock time until it stabilizes. Using the local chip-level atomic clock as the time and frequency reference source, it provides physical signal-level 1PPS, 10MHz, and TOD time services, and transmits 1PPS and TOD time and frequency information to the local processor via real-time interrupts of 1PPS events. The local processor builds a time-frequency data error compensation model based on the cumulative counters of the previous and subsequent interrupt times to compensate for the time deviation caused by the inaccurate frequency of the local processor itself; The local processor uses its own compensated TOD_S time as the time reference source. Based on the NTP network service protocol, it provides real-time, two-way wired-level time services to monitoring and surveillance network nodes with wired connection capabilities within a short range of the deployment point through the NTP timing service module. In addition, the UWB ranging communication module is used to carry TOD_S time information using UWB pulse signals as a carrier, providing one-way wireless time synchronization services for node devices within a long range of the deployment point.

2. A high-precision classification and grading time synchronization service method for dense forest environment according to claim 1, characterized in that: The GNSS observation value anomaly and multipath anomaly detection discriminant formula is: in: Where, represents the f-frequency pseudorange measurement value of the i-th GNSS satellite, C is the speed of light, I i and T i Represent the ionospheric and tropospheric delay information of the i-th GNSS satellite, δt i represents the satellite clock error of the i-th GNSS satellite, represents the pseudo-range code phase deviation of frequency f of the i-th GNSS satellite, r0 and r s Represent the known position of the deployment point and the GNSS satellite position vector respectively, represents the a priori clock error of the local chip-level atomic clock at time t, δ ρ is the threshold for judging abnormal GNSS satellite pseudorange measurements.

3. The high-precision classification and grading time synchronization service method for dense forest environment according to claim 1 is characterized in that: The GNSS single satellite time bias estimation equation constrained by the local chip-level atomic clock prior clock error information is: in, represents the f-frequency pseudorange measurement value of the i-th GNSS satellite, Represents the geometric distance between the coordinate deployment point and the i-th GNSS satellite, C is the speed of light, I i and T i Represent the ionospheric and tropospheric delay information of the i-th GNSS satellite, represents the carrier phase measurement value of frequency f of the i-th GNSS satellite, represents the pseudorange code phase deviation of frequency f of the i-th GNSS satellite, and represent the pseudorange noise and carrier phase noise of the observed frequency f of the i-th GNSS satellite, δt i represents the satellite clock error of the i-th GNSS satellite, represents the carrier phase ambiguity of the i-th GNSS satellite, δt(t) is the time deviation between the local chip-level atomic clock and the GNSS time at time t, represents the a priori clock error of the local chip-level atomic clock at time t, P δt is the prior weight of the prior observation equation.

4. The high-precision classification and grading time synchronization service method for dense forest environment according to claim 1 is characterized in that: The rule for judging abnormality of the local chip-level atomic clock time input signal is: in, represents the a priori clock error of the local chip-level atomic clock at time t, δt(t) is the time deviation between the local chip-level atomic clock and GNSS time at time t, δt(t0) is the time deviation between the local chip-level atomic clock and GNSS time at the previous time t0, and ε δt is the threshold for judging abnormality of the chip-level atomic clock time-frequency signal input at time t.

5. The high-precision classification and grading time synchronization service method for dense forest environment according to claim 1 is characterized in that: The time-frequency data error compensation model is: in: Where deltaT is the time deviation caused by the inaccurate frequency of the local processor itself, N1 and N2 are the count values ​​of the cumulative counter when the interrupt is triggered by the 1PPS signal at the current moment and the previous moment, N tod The count value of the cumulative counter when the local processor completes TOD parsing and processor time calibration.

6. The high-precision classification and grading time synchronization service method for dense forest environment according to claim 1 is characterized in that: The local processor uses its own compensated TOD_S time as the time reference source. The specific compensation method is: T tod_s =T tod +deltaT Among them, T tod and T tod_s are the TOD time information before and after compensation of the local processor, deltaT is the time deviation caused by the inaccurate frequency of the local processor itself, and T ntp Provides time information when providing NTP timing service to the local processor, N ntp The count value of the cumulative counter when providing NTP timing services to the local processor.

7. A high-precision classification and grading time synchronization service device for dense forest environments, characterized in that: Used to obtain time information through a single satellite and provide time synchronization services for surrounding node devices, including chip-level atomic clocks, satellite navigation receiving boards, processors, UWB ranging communication modules, and NTP timing service modules; The satellite navigation receiving board is used to perform the following steps: Capture and track GNSS satellite pseudorange and carrier phase observation data; Based on the tracked and captured GNSS satellite pseudorange and carrier phase observation data, and according to the known coordinates of the deployment site and the prior clock error information of the chip-level atomic clock, a discriminant function for detecting GNSS observation value anomalies and multipath anomalies is designed to realize the identification of GNSS pseudorange observation value anomalies and multipath anomalies. Construct a GNSS single-satellite time deviation estimation equation constrained by the chip-level atomic clock's a priori clock error information, and achieve estimation of the time deviation between the chip-level atomic clock and GNSS time based on a single GNSS satellite in dense forest environments with severe pseudorange multipath. The chip-level atomic clock is used to perform the following steps: Based on the time deviation between the chip-level atomic clock and GNSS time, an abnormal discrimination equation for the chip-level atomic clock time input signal is constructed; Determine whether there are any anomalies between the chip-level atomic clock and GNSS time deviation and the GNSS 1PPS signal input. If the 1PPS signal input is normal, tame the local chip-level atomic clock time until it stabilizes. Using the local chip-level atomic clock as the time and frequency reference source, it provides physical signal-level 1PPS, 10MHz, and TOD time services, and transmits 1PPS and TOD time and frequency information to the processor via real-time interrupts of 1PPS events. The processor is configured to perform the following steps: Based on the cumulative counters of the previous and next interrupt times, a time-frequency data error compensation model is constructed to compensate for the time deviation caused by the inaccurate frequency of the processor itself; The processor uses its own compensated TOD_S time as the time reference source. Based on the NTP network service protocol, it provides real-time, two-way wired-level time services to monitoring and surveillance network nodes with wired connection capabilities within a short range of the deployment point through the NTP timing service module. In addition, the UWB ranging communication module is used to carry TOD_S time information using UWB pulse signals as a carrier, providing one-way wireless time synchronization services for devices within a long range of the deployment point.

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