CN101435861B - GPS signal processing method under weak signal star searching environment - Google Patents
GPS signal processing method under weak signal star searching environment Download PDFInfo
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- CN101435861B CN101435861B CN2008102173527A CN200810217352A CN101435861B CN 101435861 B CN101435861 B CN 101435861B CN 2008102173527 A CN2008102173527 A CN 2008102173527A CN 200810217352 A CN200810217352 A CN 200810217352A CN 101435861 B CN101435861 B CN 101435861B
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Abstract
The invention provides a GPS signal processing method in the weak signal satellite searching environment. The method comprises: a mobile positioning terminal transmits a single satellite signal received to a position server by a mobile communication network in the full IP data information mode; according to the information transmitted by the mobile positioning terminal, the position server transmits auxiliary information of the satellite and other satellites near the satellite to the mobile positioning terminal; the auxiliary information transmitted to the mobile positioning terminal by the position server includes ephemerides, almanacs and azimuth elevations of the satellites; and according to the auxiliary information provided by the position server, the position of the mobile positioning terminal can be worked out. The GPS positioning product manufactured by the method has the characteristics of quick positioning speed, stable signals in the weak signal environment and high positioning accuracy; moreover, the product only needs few seconds to capture first GPS signals, in the normal GPS working environment, the positioning accuracy reaches nearly 10 meters, and in the weak signal satellite searching environment, the product can also finish the positioning task.
Description
Technical field
The present invention relates to measuring method, particularly the method for GPS location under weak signal environment.
Background technology
Present GPS scheme is because to receive the star ability more weak, and not only locating speed is slow and positioning error is big, and disconnected news also always can take place, and especially is used as in the city in location or the navigation, causes a lot of inconvenience; Separating and make a decision the query topic, is that the gps signal that signal is strong is inadequately also taken in now, has so just caused the phenomenon of drift.Signal can drift be the GPS problem (GPS of high sensitivity is to use the Xtrac technology mostly) of normal generation of Xtrac technology, because its utilize to amplify feeble signal in addition computing locate, and satellite-signal is all changing constantly, so the continuous computing of GPS is with round-off error, when difference is great before and after the receipts signal, will see the phenomenon of drift; Particularly weak the receipts under the star environment, the problem of disconnected news and drift is just more serious.Signal more weak environment in, city high rise building gap or indoor for example generally needs the time calculating locations of a few minutes.
Summary of the invention
The invention provides the gps signal disposal route under a kind of weak signal star searching environment, utilize mobile communication network to combine, solve the technical matters that received signal is bad and locating speed is slow under weak signal environment in the prior art with the GPS location technology.Adopt the network real-time location technology, further solve the big technical matters of positioning error.
Gps signal disposal route under the weak signal star searching environment provided by the invention may further comprise the steps:
A. the running fix terminal receiving satellite number of it is believed that;
B. calculate the running fix terminal location;
Also comprise step by step following in the described steps A:
A1. at first running fix terminal is transferred to location server by mobile communication network by all-IP data message mode with the single satellite-signal that itself receives;
A2. location server is according to the information of running fix terminal transmission, with this satellite and on every side the assistance information transmission of satellite give the running fix terminal.
Described step B comprises step by step following:
B1. the supplementary that provides according to location server of running fix terminal, other satellites of fast searching;
B2. accurately locate the position of running fix terminal.
The supplementary that the running fix terminal provides according to location server among the described step B calculates the position of itself; The supplementary that satellite raw information that running fix terminal basis receives among the perhaps described step B and location server provide, the position of calculating the running fix terminal;
In the described steps A 2, the supplementary that location server is transferred to the running fix terminal comprises ephemeris, almanac and the azimuth pitch angle of satellite, and the supplementary that location server provided described in the steps A 2 comes from the base station with gps receiver.
The step that the running fix terminal is calculated its position among the step B comprises:
B1. with the position data in the previous moment of running fix terminal as reference; The position data of described reference point comprises longitude and latitude, speed, direction and positioning time.
B2. behind the signal of receiving a satellite again, according to step b1 in mistiming, the direction of motion of reference point and the skew vector that speed calculates the moving object displacement of comparable data.
B3. with reference to the satellite-signal that receives among the step b2, location server provide around satellite auxiliary parameter and with reference to the offset vector that calculates among the step b2, calculate the location parameter of current running fix terminal.
Among the described step B, adopt the real-time dynamic positioning error correcting method during position of calculating running fix terminal, this method may further comprise the steps:
I. base station sends to running fix terminal on every side with moonscope value and this station coordinates that oneself obtains in real time by data communication chain;
Ii. the running fix terminal receives the moonscope value that base station sends, the broadcast ephemeris that receives in conjunction with self again, calculate and base station between relative position; Further the coordinate according to base station draws accurate position.
Described moonscope value comprises carrier phase observation data and surveys sign indicating number pseudorange observed reading, described base station distributes according to certain rules and constitutes the base station network, the running fix terminal adopts wide area differential GPS and local area differential GPS's method to eliminate the systematic error influence, reaches accurate location; The rover station suffered systematic error of base station network center in will be between three base stations sends to the running fix terminal, revises the error of running fix terminal, obtains accurately location.
The GPS location product that adopts method provided by the present invention to make, have that locating speed is fast, signal stabilization and the high characteristics of bearing accuracy under the weak signal environment, even in a kind of hostile environment, the more weak city high rise building gap of signal or indoor for example, the time that this product is caught gps signal first generally also only needs several seconds, its bearing accuracy is under normal GPS working environment, can reach about 10 meters, receive under the star environment (under high building, tree shade, the bridge, in the shield, window, car, under the chassis, indoor etc.) in weak signal and can finish location tasks too.The range of sensitivity of the civilian GPS terminal reception of tradition gps satellite signal :-125dBM～-146dBm, and the GPS location product technology range of sensitivity that adopts method provided by the present invention to make can reach-146dBm～161dBm.
Description of drawings
Fig. 1 is a principle of work synoptic diagram of the present invention.
Embodiment
The accompanying drawings specific embodiments of the invention.
By among Fig. 1 as can be known, the gps signal disposal route under a kind of weak signal star searching environment, this method may further comprise the steps:
A. the running fix terminal receiving satellite number of it is believed that;
B. calculate the running fix terminal location;
Also comprise step by step following in the described steps A:
A1. at first running fix terminal is transferred to location server by mobile communication network by all-IP data message mode with the single satellite-signal that itself receives;
A2. location server is according to the information of running fix terminal transmission, with this satellite and on every side the assistance information transmission of satellite give the running fix terminal; The supplementary that location server is transferred to the running fix terminal comprises ephemeris, almanac and the azimuth pitch angle of satellite; The supplementary that described location server provided comes from the base station with gps receiver.
Can adopt following several mode during running fix terminal calculating location:
One: described step B comprises step by step following:
B1. the supplementary that provides according to location server of running fix terminal, other satellites of fast searching;
B2. accurately locate the position of running fix terminal.
Its two: the supplementary that the running fix terminal provides according to location server among the described step B calculates position itself.
Its three: the supplementary that the running fix terminal provides according to the satellite raw information that receives and location server among the described step B, the position of calculating the running fix terminal.
The mode of calculating its position at second kind of running fix terminal may further comprise the steps:
B1. with the position data in the previous moment of running fix terminal as reference; The position data of described reference point comprises longitude and latitude, speed, direction and positioning time.
B2. behind the signal of receiving a satellite again, according to step b1 in mistiming, the direction of motion of reference point and the skew vector that speed calculates the moving object displacement of comparable data.
B3. with reference to the satellite-signal that receives among the step b2, location server provide around satellite auxiliary parameter and with reference to the offset vector that calculates among the step b2, calculate the location parameter of current running fix terminal.
Well-known gps satellite height is in the general of geostationary satellite height approximately, fly around ground time in a week is 12 hours, in the ground process in one week, every each orbit parameter constantly of gps satellite all has fixedly rule, and per 12 hours repetitive cycling once, be that every gps satellite all has its fixing ephemeris, under the prerequisite of the ephemeris parameter of knowing all gps satellites, any moment just can obtain by reckoning in its overhead gps satellite number and their orbit parameter (also being ephemeris parameter) this moment of working in the arbitrary region on earth, the GPS terminal is behind the ephemeris parameter that obtains these gps satellites, not only can search for and be locked in its overhead gps satellite fast, greatly shorten TTFF (the Time To First Fix) time, can reduce simultaneously dependence to gps satellite signal intensity, lifting is to the sensitivity of signal search, simultaneously can also provide a kind of special algorithm to make the GPS terminal under the situation that can only receive a gps satellite signal, position calculating
Among the described step B, adopt the real-time dynamic positioning error correcting method during position of calculating running fix terminal, this method may further comprise the steps:
I. base station sends to running fix terminal on every side with moonscope value and this station coordinates that oneself obtains in real time by data communication chain;
Ii. the running fix terminal receives the moonscope value that base station sends, the broadcast ephemeris that receives in conjunction with self again, calculate and base station between relative position; Further the coordinate according to base station draws accurate position.
Described moonscope value comprises carrier phase observation data and surveys sign indicating number pseudorange observed reading, described base station distributes according to certain rules and constitutes the base station network, the running fix terminal adopts wide area differential GPS and local area differential GPS's method to eliminate the systematic error influence, reaches accurate location; The rover station suffered systematic error of base station network center in will be between three base stations sends to the running fix terminal, revises the error of running fix terminal, obtains accurately location.
Primary positioning time (TTFF) is decided by the receiving sensitivity of receiver to a great extent, and the intensity of the quantity of visible satellite, each satellite-signal, satellite on high distribution and receiver to the visual angle of sky.In a kind of hostile environment, the more weak city high rise building gap of signal or indoor for example needs the time calculating locations of a few minutes under some situation.Develop auxiliary type GPS (auxiliary positioning) for this reason and solved TTFF problem under the adverse environment.The user level scheme is the aided positioning system that a kind of communication between auxiliary positioning server and mobile device all links based on the all-IP data, with wireless signaling layer irrelevant (based on the IP of GPRS).When using auxiliary positioning on user level, the mobile device of band gps receiver is connected with location server by IP on mobile network's user level.The auxiliary positioning server is supported data, for example ephemeris and almanac from several the collection with reference to gps receiver.Server sends these data as requested to mobile device.The gps receiver of mobile device utilizes this to support data to carry out the position computing.LBS can require mobile device that positional information is provided, and these data will connect transmission by IP.This method is lower than the method cost by controlling layer, because mobile network provider does not need special hardware to chain of command, and this method all is operable for all mobile standards.
Auxiliary type GPS makes and adopts quick TTFF calculating location to become possibility.For realizing this point, utilize the extraneous information as time synchronized, more accurate location, Doppler and frequency to be used for determining the position.This extraneous information can obtain by the infrastructure device of using mobile network's controlling layer, and the mechanism as AFLT (AFLT) is used to determine the position of mobile device.Here, signal sends from mobile device, and several mobile base stations receive and measure.(based on mobile device), perhaps on mobile network's server (based on network) can take place in the calculating of position in mobile device.
Adopt based on network auxiliary type GPS solution, mobile device sends the GPS secondary server of original gps data in the mobile network.This webserver can utilize and directly come the extra assistant GPS information of automatic network to come calculating location.After calculating, position data is sent to receiver.LBS or E911 service be the location database of access web server directly.
The benefit of auxiliary positioning is to improve TTFF, increase sensitivity and make the availability maximization, exist these advantages to be because receiver no longer must be downloaded and be decoded from the navigation data of gps satellite, receiver can use more time and processing power to follow the tracks of gps signal.
The present invention adopts the real-time dynamic positioning technology to combine with number teach skill arts, and the real-time resolving line data of going forward side by side is handled, and obtains high-precision position information in the time of 1～2s.
Conventional real-time positioning technology is a kind of the dynamic subscriber to be carried out the technology of real-time relative positioning, and this technology also can be used for the rapid static location.When carrying out the work of conventional real-time positioning, base station needs to give the dynamic subscriber of work around it by the data communication chain real-time broadcasting with own carrier phase observation data that be obtained (preferably add and survey a sign indicating number pseudorange observed reading) and station coordinates.So these dynamic subscribers just can carry out real-time relative positioning according to carrier phase observation data (preferably add and survey a yard pseudorange observed reading) and the broadcast ephemeris of the own identical epoch that obtains, and and then try to achieve oneself instantaneous position according to the station coordinates of base station.For eliminating the clock correction of satellite clock and receiver clock, weaken the influence of satellite ephemeris error, ionosphere delay error and tropospheric delay error, in real-time positioning, all adopt two difference observed readings usually.
The real-time positioning technology is to be based upon on the basis of rover station and this hypothesis of base station error strong correlation.Nearer (when for example being no more than 10～15km), general equal can the establishment preferably of above-mentioned hypothesis utilizes the observational datas of one or several epoch can obtain the positioning result of centimetre-sized precision this moment from base station when rover station.Yet along with the increase of spacing between rover station and base station, the error correlativity will become worse and worse.Track deviation, the residual error item of the residual error of ionosphere delay and tropospheric delay all will increase sharply.Thereby cause being difficult to correctly determining integer ambiguity, can't obtain static solution.
This technology has greatly been expanded the usage space of GPS, is representing the highest level of high-precision GPS.But the real-time positioning technology has certain limitation, and when the distance between rover station and base station during greater than 50km, separate the precision that generally can only reach decimeter grade single epoch of conventional real-time positioning, and it is restricted in application:
1. the user need set up local reference station
2. error increases with distance
3. the error growth is restricted rover station and reference station distance
4. reliability and feasibility reduce with distance.
Just must take some special method and measures in order to obtain high-precision positioning result in this case, so the network real-time location technology has just been arisen at the historic moment.
GPS network real-time location technology makes all mapping operations in an area become an organic whole, has expanded the scope of work of real-time positioning, makes the application of GPS more extensive, and precision and reliability also further improve.
The network real-time location technology integrates the system of Internet technology, wireless communication technique, computer network management and GPS location technology.If in a bigger zone, can lay a plurality of base stations sparsely, more equably, the accurate station of primordial net, we just can use for reference wide area differential GPS and have ultimate principle in the local area differential GPS of a plurality of base stations and influence that method manages to eliminate or weaken various systematic errors so, obtain high-precision positioning result, the ultimate principle of network real-time that Here it is location.
The network real-time location is by the base station net, and data processing centre (DPC) and tie line are formed.Should be equipped with the long GPS receiver of double frequency all-wave on the base station, this receiver preferably can provide accurate double frequency pseudorange observed reading simultaneously.The station coordinates of base station should be accurately known, and its coordinate can adopt method such as the static relative positioning of long-time GPS to determine.In addition, these stations also should be equipped with data communications equipment and meteorologic instrument.Base station should sampling rate in accordance with regulations carry out Continuous Observation, and sends observational data to data processing centre (DPC) in real time by data communication chain.The approximate coordinates that data processing centre (DPC) sends here according to rover station (can try to achieve according to pseudorange method single-point location) is judged this erect-position in the triangle of being made up of which three base station.Obtain the systematic error that the rover station place is subjected to according to the observational data of these three base stations then, and broadcast to mobile users and revise to obtain accurate result, can be once when being necessary with the said process iteration.
Data communication between base station and data processing centre (DPC) can adopt methods such as Digital Data Net DON or radio communication to carry out.Bidirectional data communication between rover station and data processing centre (DPC) then can be undertaken by moving modes such as electricity GSM alive.
Above content be in conjunction with concrete preferred implementation to further describing that the present invention did, can not assert that concrete enforcement of the present invention is confined to these explanations.For the general technical staff of the technical field of the invention, without departing from the inventive concept of the premise, can also make some simple deduction or replace, all should be considered as belonging to protection scope of the present invention.
Claims (10)
1. the gps signal disposal route under the weak signal star searching environment, this method may further comprise the steps:
A. the running fix terminal receiving satellite number of it is believed that;
B. calculate the running fix terminal location;
It is characterized in that: also comprise step by step following in the described steps A:
A1. at first running fix terminal is transferred to location server by mobile communication network by all-IP data message mode with the single satellite-signal that itself receives;
A2. location server is according to the information of running fix terminal transmission, with this satellite and on every side the assistance information transmission of satellite give the running fix terminal.
2. method according to claim 1 is characterized in that: described step B comprises step by step following:
B1. the supplementary that provides according to location server of running fix terminal, other satellites of fast searching;
B2. accurately locate the position of running fix terminal.
3. method according to claim 1 is characterized in that: the supplementary that the running fix terminal provides according to location server among the described step B calculates the position of itself.
4. method according to claim 1 is characterized in that: the supplementary that satellite raw information that running fix terminal basis receives among the described step B and location server provide, the position of calculating the running fix terminal.
5. according to each described method in the claim 1 to 4, it is characterized in that: in the described steps A 2, the supplementary that location server is transferred to the running fix terminal comprises ephemeris, almanac and the azimuth pitch angle of satellite.
6. method according to claim 5 is characterized in that: the supplementary that location server provided described in the steps A 2 comes from the base station with gps receiver.
7. according to the method described in the claim 3, it is characterized in that: the step that the running fix terminal is calculated its position among the step B comprises:
B1. with the position data in the previous moment of running fix terminal as reference;
B2. behind the signal of receiving a satellite again, according to step b1 in mistiming, the direction of motion of reference point and the skew vector that speed calculates the moving object displacement of comparable data;
B3. with reference to the satellite-signal that receives among the step b2, location server provide around satellite auxiliary parameter and with reference to the offset vector that calculates among the step b2, calculate the location parameter of current running fix terminal.
8. according to the method described in the claim 7, it is characterized in that: the position data of reference point described in the step b1 comprises longitude and latitude, speed, direction and positioning time.
9. according to each described method in the claim 1 to 4, it is characterized in that: among the described step B, adopt the real-time dynamic positioning error correcting method during position of calculating running fix terminal, this method may further comprise the steps:
I. base station sends to running fix terminal on every side with moonscope value and this station coordinates that oneself obtains in real time by data communication chain;
Ii. the running fix terminal receives the moonscope value that base station sends, the broadcast ephemeris that receives in conjunction with self again, calculate and base station between relative position; Further the coordinate according to base station draws accurate position.
10. method according to claim 9, it is characterized in that: described moonscope value comprises carrier phase observation data and surveys sign indicating number pseudorange observed reading, described base station distributes according to certain rules and constitutes the base station network, the running fix terminal adopts wide area differential GPS and local area differential GPS's method to eliminate the systematic error influence, reaches accurate location; The systematic error that the rover station of base station network center in will be between three base stations received sends to the running fix terminal, revises the error of running fix terminal, obtains accurately location.
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| CN2008102173527A CN101435861B (en) | 2008-11-14 | 2008-11-14 | GPS signal processing method under weak signal star searching environment |
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| CN2008102173527A CN101435861B (en) | 2008-11-14 | 2008-11-14 | GPS signal processing method under weak signal star searching environment |
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| CN101435861B true CN101435861B (en) | 2011-04-27 |
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Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8872700B2 (en) * | 2011-04-06 | 2014-10-28 | Javad Gnss, Inc. | GNSS surveying receiver with multiple RTK engines |
| CN103821120B (en) * | 2012-11-16 | 2016-01-06 | 中国科学院沈阳自动化研究所 | A kind of method reclaimed based on robot marine oil overflow |
| CN104215980B (en) * | 2013-06-05 | 2017-02-08 | 深圳市赛格导航科技股份有限公司 | GPS (global positioning system) positioning method and device |
| WO2015131398A1 (en) * | 2014-03-07 | 2015-09-11 | 华为终端有限公司 | Method and apparatus for sharing data between positioning devices |
| CN106255204B (en) * | 2016-09-30 | 2020-05-15 | 香港中文大学深圳研究院 | Data communication method and system based on angle positioning system |
| CN110197519A (en) * | 2018-02-26 | 2019-09-03 | 苏州宝时得电动工具有限公司 | Method for compensating signal, device and storage medium in map generating process |
| US11378979B2 (en) | 2017-05-26 | 2022-07-05 | Positec Power Tools (Suzhou) Co., Ltd. | Moving object and positioning method therefor, automated working system, and storage medium |
| CN113126124B (en) * | 2020-01-16 | 2022-12-06 | 千寻位置网络有限公司 | Method, server and terminal for providing auxiliary positioning information |
| CN212969077U (en) * | 2020-05-26 | 2021-04-13 | 纳恩博（北京）科技有限公司 | Charging pile |
| CN117270005B (en) * | 2023-08-14 | 2024-08-06 | 青岛港国际股份有限公司 | Mobile terminal high-precision positioning method and system based on 5G private network |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1439983A (en) * | 2002-02-19 | 2003-09-03 | 伊莱德公司 | Absolute accurate time transferrence from server to user by computing delay of network path |
| CN1588115A (en) * | 2004-09-30 | 2005-03-02 | 无锡市科迪安科技有限公司 | Quick searching method and device for portable satellite receiver |
-
2008
- 2008-11-14 CN CN2008102173527A patent/CN101435861B/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1439983A (en) * | 2002-02-19 | 2003-09-03 | 伊莱德公司 | Absolute accurate time transferrence from server to user by computing delay of network path |
| CN1588115A (en) * | 2004-09-30 | 2005-03-02 | 无锡市科迪安科技有限公司 | Quick searching method and device for portable satellite receiver |
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