CN109507690A - National standard time subnanosecond grade time service method based on GNSS - Google Patents
National standard time subnanosecond grade time service method based on GNSS Download PDFInfo
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- CN109507690A CN109507690A CN201811330386.7A CN201811330386A CN109507690A CN 109507690 A CN109507690 A CN 109507690A CN 201811330386 A CN201811330386 A CN 201811330386A CN 109507690 A CN109507690 A CN 109507690A
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
- G01S19/01—Satellite radio beacon positioning systems transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/14—Relay systems
- H04B7/15—Active relay systems
- H04B7/185—Space-based or airborne stations; Stations for satellite systems
- H04B7/18502—Airborne stations
- H04B7/18506—Communications with or from aircraft, i.e. aeronautical mobile service
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/14—Relay systems
- H04B7/15—Active relay systems
- H04B7/185—Space-based or airborne stations; Stations for satellite systems
- H04B7/1851—Systems using a satellite or space-based relay
- H04B7/18517—Transmission equipment in earth stations
Abstract
The present invention provides a kind of national standard time subnanosecond grade time service method based on GNSS, server-side observes data based on the GNSS that iGMAS and IGS tracking network generates, it generates GNSS Clock Bias product, precise satellite track product or precision and regards data altogether, and Reference clock is set as China standard time UTC (NTSC)；GNSS Clock Bias product, precise satellite track product or the accurate view data altogether are propagated by communication network；User terminal resolves the clock deviation of UTC (NTSC) and local clock together with GNSS observation data after receiving, to realize time service, and time service content is China's standard time UTC (NTSC).The present invention can directly acquire national standard time UTC (NTSC), increase time service reliability, and time service precision is increased to subnanosecond grade several nanoseconds from 10.
Description
Technical field
The present invention relates to a kind of high precision time service method, in particular to a kind of subnanosecond grade time service method.
Background technique
It determines, keep certain time scale, the temporal information for representing this scale is sent out by certain way, supply
Application person uses, this whole set of work is known as time service in China, is known as Time Service in other countries.Time service service mentions for user
For three kinds of essential informations: first is that at the time of in date and one day, it tell people's something betide when；Second is that between chronometer time
Every, it tell people's event occur experience " how long " time；Third is that standard frequency, it marks the rate of certain event methods.With
The development of human society and the progress of science and technology, Service of Timing achieves major progress.Time service service is already known to state's meter
Indispensable public good engineering in the people's livelihood, it even concerns national security.
Currently, most of time service methods are all based on certain type of radio broadcast.According to the difference of time service means
It is divided into shortwave time service, long-wave time service, TV time service, internet time service, telephone time service and satellite time transfer etc..Various Service of Timing
Precision is as shown in table 1.Wherein, satellite time transfer, signal cover is big, and transmission precision is high, and propagation attenuation is small, is extensive at present
The high precision time service method of use.
The precision of the various Service of Timing of table 1 compares
High-precision satellite time transfer depends on the high-precision space reference of GNSS and time reference, including high-precision satellite
Ephemeris and GNSS system time, so also referred to as GNSS time service.Meanwhile time service precision is also by satellite-signal and communication process shadow
It rings, including signal strength influences, troposphere and ionosphere test influence and the influence of receiver signal processing delay etc..GNSS is awarded
When basic principle be to be loaded with atomic clock in GNSS satellite, the user on ground can receive from GNSS satellite time take
Signal be engaged in correct local clock, is allowed to synchronous with GNSS clock, completes time service process.
The characteristics of due to GNSS itself, there are certain deficiencies for GNSS time service.Firstly, GNSS time service is by solving user
Position coordinates and user with respect to the GNSS system time time difference, and then correct user clock realize it is same with the GNSS system time
Step.That is, the system time that GNSS time service is kept based on each navigation system, such as GPST.And the standard time in China is
The UTC (NTSC) that National Time Service Center, Chinese Academy of Sciences generates, keeps and issue, stability is up to 10 within 100 days-16, it is much better than
The GNSS system time.If being based on national standard time UTC (NTSC) time service, it can largely improve the steady of GNSS time service
Fixed degree, at the same it is significant to China's time service system is improved.Secondly, current satellite time transfer precision is 10~40ns, it can not
Meet the demand for the higher precision that the fields such as deep space exploration, Internet of Things, scientific experiment propose the time.It is defended finally, due to navigate
Star 20000~30000km from the ground, satellite-signal is very faint, is easy to by various malicious interferences, and then influences time service
Reliability.It is based especially on a certain navigation system time service, time service reliability is lower.Therefore, a kind of high-precision is established, it is highly reliable
Property and can to improve the time service method of China's standard time be very urgent.
Summary of the invention
For overcome the deficiencies in the prior art, the present invention provides a kind of national standard time subnanosecond grade based on GNSS and awards
Shi Fangfa can be directly acquired national standard time UTC (NTSC) using this method, perfect China's standard time time service body
System；Also, this method is backed up using more GNSS, using PPP and the accurate multiple technologies means such as view altogether, on the one hand increases time service
On the other hand time service precision is increased to subnanosecond grade several nanoseconds from 10 by reliability.
The technical solution adopted by the present invention to solve the technical problems the following steps are included:
(1) server-side observes data based on the GNSS that iGMAS and IGS tracking network generates, and generates GNSS precise satellite clock
Poor product, precise satellite track product or precision regard data altogether, and Reference clock is set as China standard time UTC (NTSC)；
(2) GNSS Clock Bias product, precise satellite track product or precision described in pass through communication depending on data altogether
Internet communication；
(3) user terminal obtains GNSS by GNSS receiver and observes data, receives GNSS precise satellite by communication network
Clock deviation product, precise satellite track product or precision regard data altogether；Utilize GNSS Clock Bias product, precise satellite track
Product carries out Static Precise Point Positioning PPP；The clock of UTC (NTSC) and local clock are resolved using Static Precise Point Positioning or accurate view altogether
Difference carries out model correction to the error term in time service, to realize time service, and time service content is China's standard time UTC
(NTSC)。
The GNSS includes one of GPS, GLONASS, Galileo, BDS, QZSS, IRNSS, SBAS or a variety of group
It closes.
The GNSS Clock Bias product includes realtime product and subsequent product.
The communication network includes satellite communication network and internet.
The precision is altogether depending on carrying out total view in Asian-Pacific area selection BDS system GEO satellite.
In the step (3), while Static Precise Point Positioning and accurate view altogether resolve the clock of UTC (NTSC) and local clock
Difference mutually backs up, increases the reliability of time service.
In the step (3), when subscriber station is not in mutually visual zone, subscriber station is received by increasing deployment base station
Enter mutually visual zone；Time synchronization is realized using two-way time comparison technology between each base station.
In the step (3), when subscriber station is not in mutually visual zone, two-way ratio is established by increasing deployment and NTSC
Mutually visual zone is included in by subscriber station to the base station of link；Realize that the time is same using two-way time comparison technology between each base station
Step.
The beneficial effects of the present invention are:
1, the time service content of the time service method is China's standard time UTC (NTSC)
By to UTC (NTSC), marking time service content as China GNSS Clock Bias and the reduction of track product
Between punctual.UTC (NTSC) is the national standard time that China is autonomously generated, keeps and issues.Time service is related to national economy very
To national security, and this method is utilized, the dependence to the GNSS system time can be weakened, increases time service safety, and improve me
The time service system of national standard time.
2, the time service precision of the time service method is subnanosecond grade
This method uses high-precision Service of Timing, such as PPP and accurate view altogether, in time service observation mainly using
Carrier phase data, and model correction is carried out to the error term in time service using GNSS sophisticated product, by time service precision from current
10 be increased to magnitude of subnanosecond several nanoseconds, solve current time service precision and be unable to satisfy asking for certain high-precision applications demands
Topic.
3, the time service method reliability is higher
Compared to single navigation system time service is utilized, this method utilizes more GNSS system time services, does not depend on time dissemination system
In a certain navigation system, influence of the low reliability of single navigation system to time dissemination system is avoided.At the same time, this method
It is mutually backed up using 2 kinds of Service of Timing, increases the reliability of time dissemination system.
Detailed description of the invention
Fig. 1 is time service schematic diagram of the invention.
Specific embodiment
Present invention will be further explained below with reference to the attached drawings and examples, and the present invention includes but are not limited to following implementations
Example.
Realization of the invention relies primarily on server-side, communication network and user terminal, comprising the following steps:
The GNSS observation data that server-side is generated based on iGMAS and IGS tracking network, generation GNSS Clock Bias,
Track product or precision regard data altogether.Described GNSS refers to GPS, GLONASS, Galileo, BDS, QZSS, IRNSS, SBAS
Etc. one or more combinations of major navigation system, described GNSS Clock Bias product includes realtime product and subsequent production
Product.The Reference clock of Clock Bias product is set as China standard time UTC (NTSC).The day UTC (NTSC) is surely much better than
The system time of each navigation system such as GPST.Therefore, by setting the Reference clock of precise clock correction product to UTC (NTSC), one
Time service precision can be improved in aspect, on the other hand can reduce the dependence to GNSS system, and improve awarding for China's standard time
When system.Only when user terminal realizes time service using the accurate means of view altogether, server-side generates precision and regards data altogether.
Communication network can be realized by satellite or internet.
User terminal configures GNSS multimode (view altogether) receiver and carries out observation by GNSS receiver, obtains GNSS and observes number
According to.User terminal resolves the clock deviation of UTC (NTSC) and local clock, to realize using PPP (Static Precise Point Positioning) or accurate view altogether
Time service, and time service content is China's standard time UTC (NTSC).Described precision regards altogether, refers to and is seen using satellite carrier phase
Measured data and GNSS sophisticated product carry out total view and data processing.It is worth being especially envisaged that, can choose BDS in the Asian-Pacific area
System GEO satellite carries out total view, provides convenience for the continuous unremitting mutual comparison of both sides.When subscriber station is not in mutually visual zone
When, multiple base stations (website that two-way pumping station link is established in preferential selection with NTSC) can be disposed, in the world to expand
Mutually visual zone.Time synchronization is realized using two-way time comparison technology between each base station.
As shown in Figure 1, the step of embodiment of the present invention, is as follows:
National standard time subnanosecond grade time service method based on GNSS mainly includes server-side, communication network and user
End.The observation data that server-side is generated based on iGMAS and IGS tracking network generate GNSS Clock Bias and track product,
And the Reference clock of Clock Bias product is set as China standard time UTC (NTSC).Only when user terminal is using accurate view altogether
Means realize time service, and server-side generates precision and regards data altogether.
Communication network can be realized by satellite or internet.
User terminal configures GNSS multimode (view altogether) receiver and carries out observation by GNSS receiver, obtains GNSS and observes number
According to.User terminal resolves the clock deviation of UTC (NTSC) and local clock, to realize using PPP (Static Precise Point Positioning) or accurate view altogether
Time service, and time service content is China's standard time UTC (NTSC).Described precision regards altogether, refers to and is seen using satellite carrier phase
Measured data and GNSS sophisticated product carry out total view and data processing.
The working principle of the present embodiment is described below:
Server-side is based on iGMAS/IGS MGEX tracking network, and iGMAS analysis center generates according to formula (1), (2) with state
Family standard time UTC (NTSC) is the products such as the GNSS precision star clock deviation of reference, real-time star clock deviation.By at national time service center
NTSC places the high-precision geodetic type receiver of external UTC (NTSC), sets UTC (NTSC) for the Reference clock of satellite clock solution.
Wherein:
S is satellite number；
R is receiver number；
J is the signal of different frequency；
For Pseudo-range Observations；
For carrier phase observable；
For geometric distance, i.e. geometric distance of the satellite mass centre to receiver antenna reference point；
When for code observation, deviation of the receiver antenna phase center relative to receiver reference point, satellite antenna
Phase center is relative to centroid of satellite deviation；
When for carrier phase observable, receiver antenna phase center is relative to receiver reference point deviation, satellite antenna
Phase center is relative to centroid of satellite deviation；
dR, jWhen for pseudorange observation, receiver hardware time delay；
When for pseudorange observation, satellite hardware time delay；
δR, jWhen for phase observations, receiver hardware time delay；
When for phase observations, satellite hardware time delay；
dtrFor receiver clock-offsets；
dtsFor satellite clock correction；
For the equivalent distances of ionosphere refraction delay；
For the equivalent distances of troposphere refraction delay；
δtrelFor the correction of satellite relativistic effect；
For integer ambiguity；
Error is wound for phase；
WithFor the random error not modeled, such as receiver noise, multipath etc..
When regarding means time service altogether using accurate, server-side is total using multichannel GNSS using the GNSS sophisticated product generated
Depending on receiver, satellite is observed.Based on carrier phase data, according to formula (2), fixed station coordinates, track, and to propagation
Error carries out accurate amendment, and then generates precision and regard data altogether.It is worth being especially envisaged that, can choose BDS in the Asian-Pacific area
System GEO satellite carries out total view, provides convenience for the continuous unremitting mutual comparison of both sides.When subscriber station is not in mutually visual zone
When, multiple base stations (website that two-way pumping station link is established in preferential selection with NTSC) can be disposed, in the world to expand
Mutually visual zone.Time synchronization is realized using two-way time comparison technology between each base station.
Communication network can be met the requirements using conventional network means, such as internet, GPRS, telecommunication satellite etc..
User terminal selects subsequent, real-time GNSS sophisticated product or precision to regard data altogether, utilizes according to the demand of timeliness
PPP or accurate is altogether depending on come the clock deviation that solves local clock Yu UTC (NTSC).When user terminal uses PPP, foundation formula (1), (2),
It observes data using local, the clock deviation of local clock Yu UTC (NTSC) can be obtained, i.e. completion time service.When user terminal utilizes precision
After total view realizes that time service, user terminal generate view data altogether according to formula 1, total the making the difference depending on data with server-side generation can be obtained
To the clock deviation of local station clock and UTC (NTSC).It is worth noting that, only being needed depending on carrying out time service to user's reception altogether using accurate
Machine and the reference receiver of server-side carry out relative time delay calibration, and avoiding the absolute time-delay calibration of receiver, this is international difficult
Topic.
Claims (8)
1. a kind of national standard time subnanosecond grade time service method based on GNSS, it is characterised in that include the following steps:
(1) server-side observes data based on the GNSS that iGMAS and IGS tracking network generates, and generates GNSS Clock Bias and produces
Product, precise satellite track product or precision regard data altogether, and Reference clock is set as China standard time UTC (NTSC)；
(2) GNSS Clock Bias product, precise satellite track product or precision described in pass through communication network depending on data altogether
It propagates；
(3) user terminal obtains GNSS by GNSS receiver and observes data, receives GNSS Clock Bias by communication network
Product, precise satellite track product or precision regard data altogether；Utilize GNSS Clock Bias product, precise satellite track product
Carry out Static Precise Point Positioning PPP；The clock deviation of UTC (NTSC) and local clock are resolved using Static Precise Point Positioning or accurate view altogether, it is right
Error term in time service carries out model correction, to realize time service, and time service content is China's standard time UTC (NTSC).
2. the national standard time subnanosecond grade time service method according to claim 1 based on GNSS, it is characterised in that: institute
The GNSS stated includes one of GPS, GLONASS, Galileo, BDS, QZSS, IRNSS, SBAS or multiple combinations.
3. the national standard time subnanosecond grade time service method according to claim 1 based on GNSS, it is characterised in that: institute
The GNSS Clock Bias product stated includes realtime product and subsequent product.
4. the national standard time subnanosecond grade time service method according to claim 1 based on GNSS, it is characterised in that: institute
The communication network stated includes satellite communication network and internet.
5. the national standard time subnanosecond grade time service method according to claim 1 based on GNSS, it is characterised in that: institute
The precision stated is altogether depending on carrying out total view in Asian-Pacific area selection BDS system GEO satellite.
6. the national standard time subnanosecond grade time service method according to claim 1 based on GNSS, it is characterised in that: institute
In the step of stating (3), while Static Precise Point Positioning and accurate view altogether resolve the clock deviation of UTC (NTSC) and local clock, mutually back up,
Increase the reliability of time service.
7. the national standard time subnanosecond grade time service method according to claim 1 based on GNSS, it is characterised in that: institute
In the step of stating (3), when subscriber station is not in mutually visual zone, subscriber station is included in total view model by increasing deployment base station
It encloses；Time synchronization is realized using two-way time comparison technology between each base station.
8. the national standard time subnanosecond grade time service method according to claim 1 based on GNSS, it is characterised in that: institute
In the step of stating (3), when subscriber station is not in mutually visual zone, the base of two-way pumping station link is established by increasing deployment and NTSC
Quasi- station subscriber station is included in mutually visual zone；Time synchronization is realized using two-way time comparison technology between each base station.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110501730A (en) * | 2019-08-23 | 2019-11-26 | 中国科学院国家授时中心 | Standard time subnanosecond grade time service method based on RTK improved technology |
| CN110865532A (en) * | 2019-11-25 | 2020-03-06 | 北京无线电计量测试研究所 | Satellite-ground bidirectional time frequency synchronization method |
| CN112558118A (en) * | 2020-12-10 | 2021-03-26 | 江苏师范大学 | High-precision time service method based on communication satellite |
| CN112799107A (en) * | 2020-12-28 | 2021-05-14 | 中国科学院国家授时中心 | Dynamic time service system and method |
| CN112924992A (en) * | 2021-01-25 | 2021-06-08 | 中国科学院国家授时中心 | GEO orbit precision evaluation method and device, electronic equipment and storage medium |
| CN113721445A (en) * | 2021-07-13 | 2021-11-30 | 中国科学院国家授时中心 | Multi-region real-time dynamic time service method and device based on satellite navigation |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108415050A (en) * | 2018-06-04 | 2018-08-17 | 北京未来导航科技有限公司 | A kind of PPP-RTK localization methods enhancing system based on low rail constellation navigation |
| CN108536003A (en) * | 2018-05-24 | 2018-09-14 | 千寻位置网络有限公司 | Accurate time transmission system and method and time service service system |
-
2018
- 2018-11-09 CN CN201811330386.7A patent/CN109507690A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108536003A (en) * | 2018-05-24 | 2018-09-14 | 千寻位置网络有限公司 | Accurate time transmission system and method and time service service system |
| CN108415050A (en) * | 2018-06-04 | 2018-08-17 | 北京未来导航科技有限公司 | A kind of PPP-RTK localization methods enhancing system based on low rail constellation navigation |
Non-Patent Citations (3)
| Title |
|---|
| 张立 等: "基于IGS MGEX产品分析GPS PPP时间传递", 《时间频率学报》 * |
| 谷守周 等: "顾及轨道误差BDS/GPS实时钟差融合估计的观测权函数设计", 《测绘学报》 * |
| 高天杭 等: "基于多种软件的iGMAS跟踪站坐标精密解算与精度评估", 《测绘》 * |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110501730A (en) * | 2019-08-23 | 2019-11-26 | 中国科学院国家授时中心 | Standard time subnanosecond grade time service method based on RTK improved technology |
| CN110865532A (en) * | 2019-11-25 | 2020-03-06 | 北京无线电计量测试研究所 | Satellite-ground bidirectional time frequency synchronization method |
| CN112558118A (en) * | 2020-12-10 | 2021-03-26 | 江苏师范大学 | High-precision time service method based on communication satellite |
| CN112799107A (en) * | 2020-12-28 | 2021-05-14 | 中国科学院国家授时中心 | Dynamic time service system and method |
| CN112924992A (en) * | 2021-01-25 | 2021-06-08 | 中国科学院国家授时中心 | GEO orbit precision evaluation method and device, electronic equipment and storage medium |
| CN112924992B (en) * | 2021-01-25 | 2022-11-04 | 中国科学院国家授时中心 | GEO (geosynchronous orbit) track precision evaluation method and device, electronic equipment and storage medium |
| CN113721445A (en) * | 2021-07-13 | 2021-11-30 | 中国科学院国家授时中心 | Multi-region real-time dynamic time service method and device based on satellite navigation |
| CN113721445B (en) * | 2021-07-13 | 2023-03-10 | 中国科学院国家授时中心 | Multi-region real-time dynamic time service method and device based on satellite navigation |
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