Embodiment
The specific embodiment of the present invention is described in detail below in conjunction with accompanying drawing.
Fig. 1 is a kind of marine GNSS hi-Fix service system of the present invention, it is characterized in that: comprise the information such as pseudo range observed quantity, carrier phase observed quantity, text, time of every satellite that at least three marine fixed reference stations are arranged on fixing GNSS observed quantity acquisition station on island, ocean, receive, according to certain coding and signal madulation, gone out by antenna transmission, signal is transmitted to central station station through GEO telstar; Some flowing oceanographic buoys load GNSS receiver and marine environment sensor, described GNSS receiver receives some observation datas of GNSS, marine environment sensor can gather the meteorology and hydrology data such as seawater salinity, temperature, humidity, ocean current of ocean, described data carry out encoding according to the form similar to base station, go out through antenna transmission after signal madulation, and signal is transmitted to central station station through GEO telstar; Data link, the communication link of fixed reference station and buoy communication link, user, wherein, the communication link of fixed station and oceanographic buoy is responsible for the data of base station and buoy to be sent to central station station by GEO telstar, and user is two-way communication by the communication link of BD1 telstar; Central station station owner will configure large-scale dual-mode antenna, Data Control and processing enter, dual-mode antenna receives the observed quantity of the rough coordinates of user on ocean, the marine observed quantity of fixed reference station GNSS and the GNSS of marine marker, meteorology, water temperature data, and the information data result that described antenna receives by Data Control and processing enter issues user by BD1 telstar; Line module comprises GNSS receiver and BD1 communication module, BD1 communication module by rough coordinates issue central station station, central station station is according to the grade of user and classification, at the virtual base station of user's annex, and differential corrections and other information are handed down to user by BD1 telstar receive by GNSS receiver.
Wherein, the observation data of described flowing oceanographic buoy comprises the information such as every satellite-signal intensity, pseudo-range measurements, carrier-phase measurement, navigation message, the time received.
Wherein, described two-way communication comprises: first user needs the rough coordinates oneself, is sent to central station station; Central station station needs the information such as differential correcting, availability, completeness to be handed down to user.
Wherein, described large-scale dual-mode antenna is generally 8 ~ 15 meters of parabola antennas, and deepwater user, base station and buoy antenna just can adopt small-sized antenna.
A kind of marine GNSS hi-Fix method of servicing based on oceanographic buoy and virtual reference station of the present invention, the exact position of step a, in advance precision measurement fixed reference station, fixed reference station gathers the observed quantity of GNSS, and issues central station station after these observed quantities packing by GEO telstar; Oceanographic buoy is the observed quantity of dynamic acquisition GNSS and Ocean environment information also, also issues central station by GEO satellite; Step b, in the course of the work, user's GNSS receiver that first utilization itself is carried calculates a rough coordinates, and this rough coordinates BD1 communication module is passed to central station; After the observed quantity of base station and the buoy received is combined at step c, central station station, adopt certain mathematical model, a virtual base station near user, and the GNSS correction at virtual reference station is issued user by BD1 telstar; Steps d, user correct local GNSS receiver observed quantity after receiving these information, thus realize the hi-Fix of user.Meanwhile, central station station also or according to the type of user and rank, judges whether to be distributed to user's Ocean environment information.
Wherein, step a comprises step a1, the acquisition of fixed reference station, ocean GNSS observed quantity and the process of distribution: ocean fixed reference station addressing is on fixing island, and at least choose 3 stations, the position at fixed reference station accurately records in advance.Base station is equipped with GNSS receiver, and this receiver can gather the information such as pseudorange, carrier phase, navigation message, time of GNSS; Data processing baseband module, this module arranges GNSS observed quantity, according to the packing of certain form, coding and modulation (BPSK can be adopted to modulate), be converted to after C-band (because GEO transponder is C frequency range) through up-converter module, send through antenna, and be transmitted to central station station through GEO telstar; Meanwhile, base station also needs to configure certain continued power equipment, as solar cell etc.
The GNSS observed quantity acquisition of step a2, oceanographic buoy and the process of distribution: oceanographic buoy is configured with GNSS receiver, and this receiver can gather the information such as GNSS signal intensity, pseudorange, carrier phase, navigation message, time; Marine environment sensor, gathers as data such as meteorology and hydrology such as seawater salinity, temperature, humidity, ocean currents; Data processing baseband module, this module arranges GNSS and ocean environment observation amount, according to the packing of certain form, coding and modulation (modulation system is identical with base station), be converted to after C-band through up-converter module, send through antenna, and be transmitted to central station station through GEO telstar; Meanwhile, buoy is also equipped with battery, control system etc.
The process of the data processing at step b, central station station: ground data process center line is equipped with large-scale parabola dual-mode antenna, low-converter, baseband signal processing module, mainframe computer data processing module, BD1 communication module, continued power equipment, antenna receives the signal sent out of fixed reference station and buoy, after low-converter frequency conversion, baseband signal realizes despreading and decoding, obtains GNSS observed quantity and the ocean environment observation data of fixed reference station and buoy.
Step c, in user job process, user first by BD1 communication module from oneself rough coordinates to central station station.Data processing centre (DPC) simulates a virtual reference station at user's annex, and this card number of GNSS difference is passed to user by BD1 communication module.
Its computation process is as follows:
Pseudorange and the carrier phase observation equation at three fixed reference stations are:
In formula,
it is the three-dimensional position of i-th (i=1,2,3) individual base station;
pseudo-range measurements and the carrier-phase measurement of an i-th station observation jth satellite respectively;
it is a jth pseudorange error that satellite position error causes at the i-th station; Dt
jit is Satellite clock errors;
i-th base station ionospheric error;
i-th base station tropospheric error; (x
j, y
j, z
j) be the actual position of a jth satellite.
Obtained by equation (1) and (2):
So, the ionospheric error of three base stations can be obtained.
Due to, the positional distance of three base stations is not far, can three base stations
dt
jwith
regard identical error as.That is,
3 unknown numbers are only had, so can in the hope of Δ p in above formula 3 equations
j, dt
jand d
trop.
When user job time, first to provide its rough coordinates (x
u, y
u, z
u), in order to simplify ionosphere mathematical model, remove the impact of height, the ionosphere mathematical model in research same level, is first converted into terrestrial coordinate user coordinates, namely
the position of three base stations is also converted to terrestrial coordinate simultaneously
with
learn from calculating above, this ionosphere of 3 obtains, and adopts plane equation to ionosphere modeling:
The ionosphere numerical value of three reference points is brought into equation above, constant (a, b, c) can be determined, namely determine ionosphere mathematical model.For any user
bring equation (5) into, can ionospheric error be obtained.
Therefore, Data processing center station, these Correction of Errors numbers, joins same Ocean environment information, as interference source, seawater salinity, ocean temperature, wind direction etc. adopt BD1 communication module to pass to user together.
The precision positioning of steps d, subscriber station
Subscriber station is equipped with GNSS receiver and BD1 communication module, during user job, the rough coordinates of user is first obtained by GNSS receiver, and issue central station station by BD1 communication module, central station station calculates GNSS Correction of Errors number and the Ocean environment information of user, and issuing user by BD1 communication module, user obtains these Correction of Errors numbers
the GNSS receiver positioning result of correction itself,
When to observe 4 and above satellite simultaneously, the exact position of user just can be reached.
The invention has the advantages that: marine GNSS hi-Fix service system and method that hi-Fix and environmental monitoring reporting services are provided to ocean user by the data processing of the GEO telstar passback of the collection of the GNSS observation data of the GNSS observation data collection of marine fixed reference station, mobile buoy and oceanographic observation data, GNSS observation data, central station, GNSS differential corrections and the distribution of environmental data, the hi-Fix of user etc.
As described above, be only preferred embodiment, and not for limiting the scope of the invention, all equivalences done according to the present patent application the scope of the claims change or modify, and are all the present invention and contain.