CN110133997B - Method for detecting satellite clock abnormity - Google Patents

Method for detecting satellite clock abnormity Download PDF

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CN110133997B
CN110133997B CN201910413208.9A CN201910413208A CN110133997B CN 110133997 B CN110133997 B CN 110133997B CN 201910413208 A CN201910413208 A CN 201910413208A CN 110133997 B CN110133997 B CN 110133997B
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CN110133997A (en
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苏盛
刘亮
曹一家
匡文凯
张恒
陈清清
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Changsha University of Science and Technology
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    • G—PHYSICS
    • G04—HOROLOGY
    • G04D—APPARATUS OR TOOLS SPECIALLY DESIGNED FOR MAKING OR MAINTAINING CLOCKS OR WATCHES
    • G04D7/00—Measuring, counting, calibrating, testing or regulating apparatus
    • G—PHYSICS
    • G04—HOROLOGY
    • G04R—RADIO-CONTROLLED TIME-PIECES
    • G04R20/00—Setting the time according to the time information carried or implied by the radio signal
    • G04R20/02—Setting the time according to the time information carried or implied by the radio signal the radio signal being sent by a satellite, e.g. GPS

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Abstract

A method for detecting satellite clock abnormity includes decoding satellite signal to obtain message information and sending it to CPU, judging whether information flow decoded and read out from message information is correct or not by CPU, controlling time processing module to discipline PPS by 1PPS if it is correct, estimating standard deviation between 1PPS and world standard time and accumulated error of PPS by setting up weighted least square estimation model, comparing estimated standard deviation with standard deviation set value of GPS/BDS receiver, carrying out error correction on PPS by time processing module if it is less than set value, carrying out continuity and trend judgment on corrected time interval error of PPS, outputting corrected PPS if it is correct. According to the method, through multi-link detection, whether the satellite clock is abnormal or not can be effectively identified, high-precision clock signal output is achieved, and the influence of the abnormal satellite clock on the output time of the time synchronization device is prevented.

Description

Method for detecting satellite clock abnormity
Technical Field
The invention relates to a satellite time service system, in particular to a method for detecting satellite clock abnormity.
Background
In recent years, the hidden security defect of the global positioning system is increasingly highlighted. The civil global satellite navigation system is used for transmitting navigation messages in a clear text, the defect that an encryption authentication mechanism is lacked in deception attack is overcome, and a beautiful army unmanned aerial vehicle is captured by deception landing through issuing fictitious satellite navigation messages in 2011. Subsequent research shows that the fabricated navigation message can be launched to carry out satellite clock synchronization attack on a mail carrier, an automatic driving automobile and the like which carry out automatic driving based on a GPS global positioning system. Furthermore, power monitoring systems that must operate on a uniform time reference may also be subject to satellite clock synchronization attacks.
The reason for this is that the feasibility of satellite clock synchronization attack is closely related to the existing satellite timing. Traditionally, a time synchronization device preferentially adopts a GPS/BDS (Beidou satellite System) satellite as a main clock source and uses the GPS/BDS satellite as a reference clock to time a local clock, so that a system outputs accurate time; when the GPS/BDS signals are lost, the time synchronization device uses the local clock signals as the time reference to keep time.
Aiming at the threat of time synchronization attack, a power system issues a new standard to definitely require continuous detection on a satellite clock, and the continuous detection requires that a clock difference value is within 1 us; if the clock signal is about 1us, judging that the GPS/Beidou satellite clock signal is abnormal. The new specification can prevent the clock attack with the time error being more than 1us, but the new specification can not effectively prevent the continuous clock attack with the time error being within 1us, namely: if the deviation is within the allowable range in each attack, the system time error value can be accumulated to be larger than the allowable value through continuous attack. Taking the WAMS wide area measurement and control system as an example, if the attack is continued by 0.2us per second deviation (within the time deviation allowable range of the new specification), the 600 s-continuous synchronous time attack may cause 0.12ms time deviation, thereby causing 2.16 ° power angle difference, which may result in wrong control decision.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a method for detecting the abnormality of a satellite clock, which can effectively identify the abnormal satellite clock and prevent a time synchronization device from outputting wrong clock information caused by continuous deception jamming of a GPS/BDS.
In order to achieve the purpose, the invention adopts the following technical scheme: a method of detecting satellite clock anomalies, the method comprising the steps of:
step 1: the GPS/BDS receiver decodes the received satellite signals and then outputs message information and 1PPS signals, the message information is transmitted to the CPU, and the 1PPS signals are transmitted to the time processing module;
step 2: after receiving message information sent by a GPS/BDS receiver, a CPU reads the message information and judges a satellite clock according to the read information flow, and when the information flow is correct, the satellite clock is normal; otherwise, the satellite clock is abnormal;
and step 3: the time processing module receives 1PPS sent by the GPS/BDS receiver, the CPU controls the 1PPS whether to tame the PPS or not, the 1PPS is used for taming the PPS under the condition that the CPU judges that message information is normal, meanwhile, a weighted least square estimation model is established, the standard deviation between the 1PPS and the world standard time is estimated, the standard deviation is compared with a threshold value, namely a standard deviation set value of the GPS/BDS receiver, if the standard deviation is not less than the threshold value, a satellite clock is abnormal, the time processing module sends an alarm signal to the CPU, and the CPU controls the time processing module to stop the taming of the 1 PPS; if the standard deviation is smaller than the threshold value, correcting the PPS by a time processing module, then judging the continuity of the corrected time interval error of the PPS, and if the corrected time interval error of the PPS is not within 1us, judging that the corrected time interval error of the PPS is not continuous and the satellite clock is abnormal; if the corrected time interval error of the PPS is within 1us, continuity is achieved, trend judgment is continuously carried out on the corrected time interval error of the PPS, namely whether continuous accumulated increase or decrease trend exists in jumping of the corrected PPS or not is checked under different time windows under the condition that the corrected time interval error of the PPS is within 1us, if the continuous accumulated increase or decrease trend exists, the corrected PPS is abnormal, and the output time of the time synchronizer is based on the local clock. Otherwise, the satellite clock is normal, the satellite time service is normal, and the corrected PPS is sent to the output module for output.
The calculation process of estimating the standard deviation between 1PPS and the universal standard time by establishing the weighted least square estimation model in the step 3 is as follows:
(1) there is a random error epsilon between the pulses of seconds generated by the GPS/BDS receiver and the world standard time, epsilon obeying a normal distribution: epsilon to N (0, delta)2) Wherein δ is the standardDifference, delta2Is the variance;
(2) under the time sequence X belongs to N, X is 1, 2, 3, 4
Figure BDA0002063495510000031
And setting the local high-precision crystal oscillator to output the ith second pulse
Figure BDA0002063495510000032
f(xi) The accumulated error function of the crystal oscillator is x ═ i; deviation of the crystal oscillator pulse-per-second PPS from the GPS/BDS pulse-per-second 1PPS
Figure BDA0002063495510000033
(3) For f (x)i) Performing weighted least squares estimation
Figure BDA0002063495510000034
Wherein, W is a weighting coefficient, and W belongs to (0, 1); then related to f (x) for Si) Obtaining a standard equation set after the partial derivation of the parameters, and solving the standard equation set to obtain f (x)i) Given X, f (X) is calculatedi) A value of (d);
(4) measuring the deviation y between PPS and 1PPSiAccording to yi＝f(xi)+εiCalculating a random error εi；
(5) According to the variance
Figure BDA0002063495510000041
Calculating delta2And then the standard deviation δ is calculated.
The process of correcting the PPS in the step 3 is as follows:
(1) under the condition that the time sequence x belongs to N, setting a local high-precision crystal oscillator to output ith second pulse
Figure BDA0002063495510000042
f(xi) And is a crystal oscillator accumulated error function, i ═ x,
(2) for f (x)i) Performing weighted least squares estimation
Figure BDA0002063495510000043
Wherein, W is a weighting coefficient, and W belongs to (0, 1); then related to f (x) for Si) Obtaining a standard equation set after the partial derivation of the parameters, and solving the standard equation set to obtain f (x)i) Is calculated to obtain f (x)i)；
(3) According to
Figure BDA0002063495510000044
Computing
Figure BDA0002063495510000045
Namely the modified PPS.
The calculation process of the time interval error of the PPS corrected in the step 3 is as follows:
(1) setting and outputting the ith corrected pulse per second under the time sequence x epsilon N
Figure BDA0002063495510000046
f(xi) The accumulated error function of the crystal oscillator is x ═ i;
(2) setting the output i +1 th corrected second pulse under the time sequence x epsilon N
Figure BDA0002063495510000047
Figure BDA0002063495510000048
(3) The time interval error between the output of the (i + 1) th corrected second pulse and the output of the ith corrected second pulse
Figure BDA0002063495510000049
Then ti＝f(xi+1)-f(xi)；
(4) For f (x)i) Performing weighted least squares estimation
Figure BDA00020634955100000410
Wherein, W is a weighting coefficient, and W belongs to (0, 1); then related to f (x) for Si) Obtaining a standard equation set after the partial derivation of the parameters, and solving the standard equation set to obtain f (x)i) Given X, f (X) is calculatedi) (ii) a F (x) is obtained by calculation in the same wayi+1)；
(5) According to ti＝f(xi+1)-f(xi) Calculating ti。
The basic information in step 2 includes the validity of the positioning data, the number of locked satellites and the time of more than second. The basic information is correct, namely the positioning data is effective when being displayed in an A mode, the number of the locked satellites reaches more than four, and the time information is consistent with that of the second level or more.
The method comprises the steps of establishing a weighted least square method error estimation model, selecting a relevant characteristic value (such as standard deviation of pulse per second error output by GPS/BDS) and comparing the characteristic value with a standard deviation set value of a GPS/BDS receiver to judge whether a satellite clock is abnormal or not; the jump of output time and trend judgment are added before output, and the output time is effectively detected; when the GPS/BDS satellite signals are judged to be out of step or abnormal, local high-precision crystal oscillator second pulse PPS is compensated (corrected) through the constructed weighted least square method error estimation model, and accurate time service is realized.
The invention has the beneficial effects that: the invention realizes high-precision clock signal output by analyzing potential safety hazards in the existing satellite time service system in the power system, combining the time synchronization principle and identifying whether the satellite clock is abnormal or not by a multi-link detection method.
The invention is further explained below with reference to the drawings and the embodiments.
Drawings
FIG. 1 is a flow chart of the detection method of the present invention.
FIG. 2 is a statistical view of the random error of 1PPS in the present invention (the abscissa indicates 1 PPS).
FIG. 3 is a statistical chart of the corrected PPS interval error under the normal condition of the 1PPS in the present invention.
FIG. 4 is a statistical chart of the corrected PPS interval error in case of 1PPS abnormality in the present invention.
The abscissa in fig. 3 and 4 represents the PPS after the correction.
Detailed Description
The invention relates to a method for detecting satellite clock abnormity, which combines the satellite time service principle and adopts a CPU segment to detect the satellite clock in a time synchronization device.
The invention relates to a method for detecting satellite clock abnormity, which is combined with a reference figure 1, and comprises the following detection steps:
step 1: the GPS/BDS receiver decodes the received satellite signals and then outputs message information and 1PPS signals, the message information is transmitted to the CPU, and the 1PPS signals are transmitted to the time processing module;
step 2: after receiving message information sent by a GPS/BDS receiver, a CPU reads the message information and judges a satellite clock according to the read information flow (including positioning data validity, satellite locking number, time more than second level and the like), and when the positioning data is valid when the positioning data is displayed in an A mode, the satellite locking number is more than four, and the time information more than second level is consistent, the message information signal is judged to be normal, and the satellite clock is normal; otherwise, the satellite clock is abnormal, the satellite clock has safety risk, and the output time of the time synchronization device takes the local clock as a reference;
and step 3: the time processing module receives a 1PPS signal sent by the GPS/BDS receiver, and the CPU controls whether the 1PPS tames the PPS or not; under the condition that the CPU judges that the message information is normal, 1PPS is used for taming the PPS; the time processing module simultaneously estimates the standard deviation between 1PPS and the world standard time and compares the estimated standard deviation with a threshold value (namely, a standard deviation set value delta of a GPS/BDS receiver)Is provided with) Comparing, if the standard deviation is not less than the threshold value, the satellite clock is abnormal, the time processing module sends an alarm signal to the CPU, and the CPU controls the time processing module to stop the taming of the 1PPS to the PPS; and if the standard deviation is smaller than the threshold value, correcting the PPS by the time processing module.
The above-mentioned process of domesticating PPS (i.e., local high-precision crystal oscillator-second pulse, referred to as PPS) with 1PPS is conventional in the art.
The estimation of the standard deviation between the 1PPS and the world standard time is performed by establishing a weighted least square estimation model according to the characteristics of the random error of the GPS/BDS receiver and the accumulated error of the local high-precision crystal oscillator, which is specifically as follows:
there is a random error epsilon between the pulses of seconds generated by the GPS/BDS receiver and the world standard time, epsilon obeying a normal distribution: epsilon to N (0, delta)2) Where, δ is the standard deviation, δ2Is the variance, δ and δ2Can reflect the discrete degree of random error. GPS/BDS receivers of different grades, standard deviation set value deltaIs provided withDifference (standard deviation set value delta)Is provided withKnown from GPS/BDS receiver product specifications).
Setting the ith second pulse output by the GPS/BDS receiver based on the world standard time under the time sequence x epsilon N (x is 1, 2, 3, 4.. N)
Figure BDA0002063495510000071
Wherein epsiloni～N(0，δ2) Random error; and setting the ith second pulse output by the local high-precision crystal oscillator
Figure BDA0002063495510000072
The accumulated error function of the crystal oscillator can be a linear model or a multiple model, and is determined according to the precision requirement of the crystal oscillator; in the above two formulae, i ∈ N (i ═ 1, 2, 3, 4.. N), and x ═ i. Therefore, the deviation between the second pulse of the crystal oscillator and the second pulse of the GPS/BDS
Figure BDA0002063495510000073
Deviation yiCan be obtained by measurement of an electronic device phase discriminator and the like.
Analyzing the time series X and the deviation series yiFor f (x)i) Performing weighted least squares estimation
Figure BDA0002063495510000074
Wherein W is a weighting coefficient, W belongs to (0, 1), and W is determined according to the application environment of the local high-precision crystal oscillatorThe physical property of the self-body is determined. Then related to f (x) for Si) Obtaining a standard equation set after partial derivation of the parameters, and solving the standard equation set to obtain f (x)i) Given X, f (X) is calculatedi)(f(xi) The calculation process of (a) is prior art).
According to yi＝f(xi)+εiThen the random error epsilon can be calculatedi。
According to the variance
Figure BDA0002063495510000081
(prior art) from which δ can be calculated2Thus, the standard deviation δ is known.
The above mentioned process of correcting PPS is:
setting a local high-precision crystal oscillator to output the ith pulse per second under a time sequence x epsilon N (x is 1, 2, 3, 4.. N)
Figure BDA0002063495510000082
f(xi) And (3) the accumulated error function of the crystal oscillator is that i is x. F (x) can be calculated according to the weighted least square estimation model constructed in the step 3i) Expression of values such that given X, f (X) can be calculated in time seriesi) Is calculated to obtain
Figure BDA0002063495510000083
I.e. the modified PPS.
Then, the time processing module carries out continuity judgment on the corrected time interval error of the PPS, and if the corrected time interval error of the PPS is not within 1us, the corrected time interval error of the PPS is not continuous and the satellite clock is abnormal; if the corrected time interval error of the PPS is within 1us, continuity exists, trend judgment is continuously carried out on the corrected time interval error of the PPS, namely whether the jump of the corrected PPS has a trend of continuous cumulative increase or decrease is checked under the condition that the corrected time interval error of the PPS is within 1us and in different time windows, if the jump is continuously cumulatively increased or decreased, the corrected PPS is abnormal, a satellite clock has a safety risk, and the output time of a time synchronization device is based on a local clock. Otherwise, the satellite clock is normal, the satellite time service is normal, the corrected PPS is sent to the output module to be output, and the output module outputs the corrected PPS.
The corrected PPS time interval error is calculated by utilizing the characteristics that the local high-precision crystal oscillator second pulse has an accumulated error and the GPS second pulse has a random error, so that more accurate time information can be acquired. The specific calculation process of the corrected PPS time interval error is as follows:
(1) setting and outputting the ith corrected pulse per second under the time sequence x epsilon N
Figure BDA0002063495510000091
f(xi) The accumulated error function of the crystal oscillator is x ═ i;
(2) setting the output i +1 th corrected second pulse under the time sequence x epsilon N
Figure BDA0002063495510000092
Figure BDA0002063495510000093
(3) Then, the time interval error between the output i +1 th corrected second pulse and the output ith corrected second pulse
Figure BDA0002063495510000094
Then ti＝f(xi+1)-f(xi)；
The continuity judgment mentioned above is to judge whether or not the time interval error of the PPS after the correction is within 1 us. If the time interval error of the corrected PPS is not within 1us, the satellite clock is abnormal; if the average value is within 1us, trend judgment is performed.
The trend judgment is to check whether the jump of the corrected PPS has a trend of continuously and cumulatively increasing or decreasing in different time windows under the condition that the time interval error of the corrected PPS is within 1 us. If the continuous accumulation increases or decreases, the corrected PPS is abnormal, the satellite clock has safety risk, and the output time of the time synchronization device is based on the local clock. Otherwise, the satellite clock is normal, the satellite time service is normal, the corrected PPS is sent to the output module to be output, and the output module outputs the corrected PPS.
The modified PPS should have random transitions at different time windows under the condition that the time interval error of the modified PPS is within 1 us. Under normal conditions, the time interval errors of the PPS are distributed in a dot shape, and the jumps under different time windows (such as 30min, 60min and 90min …) are up and down jumps (positive and negative jumps are represented in coordinates), so that the continuous accumulated increasing or decreasing trend does not exist. The invention carries out trend judgment on the time interval error of the output time (namely the modified PPS), and can prevent more precise attack.
Example 1
The method comprises the steps of collecting 1PPS generated after 38000 GPS receivers decode satellite signals under normal conditions, calculating the random error between the GPS receivers and the world standard time by using the method, and calculating the result as shown in figure 2, wherein the mean value of the 1PPS generated by the GPS receivers is 0, the random error range is-60 ns to 60ns, and the random error range is consistent with the normal distribution condition of the actual 1PPS random error, so that the feasibility of estimating the random error by constructing a weighted least square method model under a time sequence is shown. Meanwhile, the calculated time interval error of the corrected PPS is shown in fig. 3, and the time interval error is within 1us, which shows that the jump does not tend to change: there is no continuous increase or decrease.
A nanosecond positive value deviation is injected into 1PPS generated by a GPS receiver through a pulse increasing and decreasing controller, and the time interval error of the corrected PPS is calculated by the method of the invention, as shown in figure 4, the injected deviation is small, so that the continuity judgment and detection can be bypassed, but the jump of the PPS has a continuous accumulation increasing trend, and the 1PPS is considered to be abnormal at the moment. Therefore, by adopting the method, the trend judgment of the PPS jump is carried out while the output time continuity judgment is carried out, and the satellite abnormity can be identified.

Claims (5)

1. A method for detecting satellite clock anomalies, the method comprising the steps of:
step 1: the GPS/BDS receiver decodes the received satellite signals and then outputs message information and 1PPS signals, the message information is transmitted to the CPU, and the 1PPS signals are transmitted to the time processing module;
step 2: after receiving message information sent by a GPS/BDS receiver, a CPU reads the message information and judges a satellite clock according to the read information flow, and when the information flow is correct, the satellite clock is normal; otherwise, the satellite clock is abnormal;
and step 3: the time processing module receives 1PPS sent by the GPS/BDS receiver, the CPU controls the 1PPS whether to tame the PPS or not, the 1PPS is used for taming the PPS under the condition that the CPU judges that message information is normal, meanwhile, a weighted least square estimation model is established, the standard deviation between the 1PPS and the world standard time is estimated, the standard deviation is compared with a threshold value, namely a standard deviation set value of the GPS/BDS receiver, if the standard deviation is not less than the threshold value, a satellite clock is abnormal, the time processing module sends an alarm signal to the CPU, and the CPU controls the time processing module to stop the taming of the 1 PPS; if the standard deviation is smaller than the threshold value, correcting the PPS by a time processing module, then judging the continuity of the corrected time interval error of the PPS, and if the corrected time interval error of the PPS is not within 1us, judging that the corrected time interval error of the PPS is not continuous and the satellite clock is abnormal; if the time interval error of the corrected PPS is within 1us, continuity is achieved, trend judgment is continuously carried out on the time interval error of the corrected PPS, namely whether the jump of the corrected PPS has a trend of continuous accumulation increase or decrease is checked under the condition that the time interval error of the corrected PPS is within 1us and in different time windows, if the jump is continuously accumulated and increased or decreased, the corrected PPS is abnormal, a satellite clock has a safety risk, and the output time of a time synchronization device is based on a local clock; otherwise, the satellite clock is normal, the satellite time service is normal, and the corrected PPS is sent to the output module for output.
2. The method according to claim 1, wherein the step 3 of establishing a weighted least squares estimation model to estimate the standard deviation between 1PPS and the standard time of the world is performed as follows:
(1) there is a random error epsilon between the pulses of seconds generated by the GPS/BDS receiver and the world standard time, epsilon obeying a normal distribution: epsilon to N (0, delta)2) Where, δ is the standard deviation, δ2Is the variance;
(2) under the time sequence X belongs to N, X is 1, 2, 3, 4.. N, the ith second pulse output by the GPS/BDS receiver is set based on the world standard time
Figure FDA0002063495500000021
i ═ x; and setting the ith second pulse output by the local high-precision crystal oscillator
Figure FDA0002063495500000022
f(xi) The accumulated error function of the crystal oscillator is x ═ i; deviation of the crystal oscillator pulse-per-second PPS from the GPS/BDS pulse-per-second 1PPS
Figure FDA0002063495500000023
(3) For f (x)i) Performing weighted least squares estimation
Figure FDA0002063495500000024
Wherein, W is a weighting coefficient, and W belongs to (0, 1); then related to f (x) for Si) Obtaining a standard equation set after the partial derivation of the parameters, and solving the standard equation set to obtain f (x)i) Given X, f (X) is calculatedi) A value of (d);
(4) measuring the deviation y between PPS and 1PPSiAccording to yi＝f(xi)+εiCalculating a random error εi；
(5) According to the variance
Figure FDA0002063495500000025
Calculating delta2And then the standard deviation δ is calculated.
3. The method of claim 1, wherein the step 3 of correcting the PPS comprises:
(1) under the condition that the time sequence x belongs to N, setting a local high-precision crystal oscillator to output ith second pulse
Figure FDA0002063495500000026
f(xi) And is a crystal oscillator accumulated error function, i ═ x,
(2) for f (x)i) Performing weighted least squares estimation
Figure FDA0002063495500000031
Wherein, W is a weighting coefficient, and W belongs to (0, 1); then related to f (x) for Si) Obtaining a standard equation set after partial derivation of the parameters, and solving the standard equation set to obtain f (x)i) Is calculated to obtain f (x)i)；
(3) According to
Figure FDA0002063495500000032
Computing
Figure FDA0002063495500000033
Namely the modified PPS.
4. The method of claim 1, wherein the PPS time interval error corrected in step 3 is calculated as follows:
(1) setting and outputting the ith corrected pulse per second under the time sequence x epsilon N
Figure FDA0002063495500000034
f(xi) The accumulated error function of the crystal oscillator is x ═ i;
(2) setting the output in the time series x ∈ NThe i +1 th corrected pulse per second
Figure FDA0002063495500000035
Figure FDA0002063495500000036
x＝i+1；
(3) The time interval error between the output of the (i + 1) th corrected second pulse and the output of the ith corrected second pulse
Figure FDA0002063495500000037
Then ti＝f(xi+1)-f(xi)；
(4) For f (x)i) Performing weighted least squares estimation
Figure FDA0002063495500000038
Wherein, W is a weighting coefficient, and W belongs to (0, 1); then related to f (x) for Si) Obtaining a standard equation set after partial derivation of the parameters, and solving the standard equation set to obtain f (x)i) Given X, f (X) is calculatedi) (ii) a F (x) is obtained by calculation in the same wayi+1)；
(5) According to ti＝f(xi+1)-f(xi) Calculating ti。
5. The method as claimed in claim 1, wherein the information stream in step 2 comprises the validity of the positioning data, the number of locked satellites and the time of more than second.
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CN117318871B (en) * 2023-11-29 2024-02-27 四川蜀能电科能源技术有限公司 Time protection method, equipment and medium for power monitoring system

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005134215A (en) * 2003-10-29 2005-05-26 Furuno Electric Co Ltd System for measuring difference of signal arrival time
CN101079687A (en) * 2006-05-25 2007-11-28 上海欣泰通信技术有限公司 A clock adjustment algorithm based on minimum two multiplexing model
CN102291169A (en) * 2011-09-09 2011-12-21 航天东方红卫星有限公司 Onboard high-accuracy time synchronization method for satellite
CN103777518A (en) * 2014-01-22 2014-05-07 天津七一二通信广播有限公司 Satellite navigation timing system and method based on improved least square method
CN104330966A (en) * 2014-10-22 2015-02-04 中国人民解放军信息工程大学 Multi-mode high-precision time and frequency standard equipment
CN106154822A (en) * 2015-03-27 2016-11-23 北京机电工程研究所 The method for synchronizing time of satellite locking rubidium atomic clock and localizer station
JP2017150834A (en) * 2016-02-22 2017-08-31 Ｎｅｃスペーステクノロジー株式会社 Artificial satellite, satellite system, and method for confirming internal time of artificial satellite
CN107247405A (en) * 2017-04-14 2017-10-13 广州北极瑞光电子科技有限公司 A kind of satellite navigation time service is kept time the solution in clock system
CN207717984U (en) * 2018-02-01 2018-08-10 杭州腾振科技有限公司 A kind of synchronous data acquisition circuit based on Global Satellite Navigation System
CN109143283A (en) * 2018-02-24 2019-01-04 上海华测导航技术股份有限公司 A kind of design method for the satellite receiver that high-precision PPS is provided for accurate time transmission

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107422342A (en) * 2017-08-03 2017-12-01 千寻位置网络有限公司 GNSS satellite clock correction estimates method of quality control in real time

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005134215A (en) * 2003-10-29 2005-05-26 Furuno Electric Co Ltd System for measuring difference of signal arrival time
CN101079687A (en) * 2006-05-25 2007-11-28 上海欣泰通信技术有限公司 A clock adjustment algorithm based on minimum two multiplexing model
CN102291169A (en) * 2011-09-09 2011-12-21 航天东方红卫星有限公司 Onboard high-accuracy time synchronization method for satellite
CN103777518A (en) * 2014-01-22 2014-05-07 天津七一二通信广播有限公司 Satellite navigation timing system and method based on improved least square method
CN104330966A (en) * 2014-10-22 2015-02-04 中国人民解放军信息工程大学 Multi-mode high-precision time and frequency standard equipment
CN106154822A (en) * 2015-03-27 2016-11-23 北京机电工程研究所 The method for synchronizing time of satellite locking rubidium atomic clock and localizer station
JP2017150834A (en) * 2016-02-22 2017-08-31 Ｎｅｃスペーステクノロジー株式会社 Artificial satellite, satellite system, and method for confirming internal time of artificial satellite
CN107247405A (en) * 2017-04-14 2017-10-13 广州北极瑞光电子科技有限公司 A kind of satellite navigation time service is kept time the solution in clock system
CN207717984U (en) * 2018-02-01 2018-08-10 杭州腾振科技有限公司 A kind of synchronous data acquisition circuit based on Global Satellite Navigation System
CN109143283A (en) * 2018-02-24 2019-01-04 上海华测导航技术股份有限公司 A kind of design method for the satellite receiver that high-precision PPS is provided for accurate time transmission

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
基于GPS秒脉冲的参考源实时校正算法;吴勇;《红外与激光工程》;20141231;第43卷;全文 *

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