CN103675875B - Mixing difference method between the B2/L2 carrier phase star of BDS and GPS - Google Patents

Abstract

A mixing difference method between the B2/L2 carrier phase star of BDS and GPS, relates to global position system and location survey technical field.Receiver user receive dipper system and gps system dual system separately satellite broadcast to the observation data of receiver user, determine dipper system B2 ambiguity of carrier phase and gps system L2 ambiguity of carrier phase respectively by carrier phase observation equation; Recover the integer characteristic of difference blur level parameter between dipper system and gps system B2/L2 frequency carrier phase mixing star; Determine that the user's Big Dipper/GPS is to satellite distance.The present invention can avoid the impact that dipper system B2 carrier phase is different from both gps system L2 carrier phases frequency, makes the blur level Parameter reconstruction integer characteristic of difference between B2/L2 frequency carrier phase mixing star.

Description

Mixing difference method between the B2/L2 carrier phase star of BDS and GPS

Technical field

The present invention relates to global position system and location survey technical field, mixing difference method between the B2/L2 carrier phase star of particularly a kind of BDS and GPS.

Background technology

When hi-Fix is carried out with the receiver of gps system dual system to BDS system (BeiDou Navigation Satellite System), one of technological means of current employing be exactly utilize carrier phase star between difference combination technique determination carrier phase observation data, and then obtain receiver to the distance value of satellite, finally utilize receiver to calculate the position of receiver to the distance of satellite.

Current worldwide navigation positioning system (GNSS), when carrying out difference combination between carrier phase star, can only carry out difference between single system, B2 or L2 single frequency carrier phase observation data.The reason can only carrying out difference combination between single system with single frequency carrier phase observation data is that the wavelength of B2 with L2 frequency carrier phase place is different, after between BDS system and gps system star, B2 and L2 frequency observation value difference divides combination, between B2 and L2 frequency carrier phase place star, the blur level of difference observed reading does not possess integer characteristic.If not using difference blur level between star as parameter, and with single satellite for object carries out blur level parameter calculation, be difficult to eliminate error relevant with receiver in single satellite observation, thus the parameter making needs estimate increases, simultaneously due to the existence of receiver about error, the blur level of B2 and L2 frequency carrier carrier phase observable cannot calculate rapidly and accurately.

Summary of the invention

For the deficiency that prior art exists, the object of the invention is the B2 carrier phase observation data and the gps system L2 carrier phase observation data that utilize BDS system, difference combination between mixing star is carried out to the B2/L2 carrier phase observation data of two systems, and the integer characteristic of difference B2/L2 carrier phase ambiguity between mixing star can be recovered, when realizing the high-precision real of BDS system and gps system carrier phase observation data better, fast joint is located, and improves dual system location service capability.

Mixing difference method between the B2/L2 carrier phase star that technical scheme of the present invention is achieved in that a kind of BDS and GPS, comprises the following steps:

Step 1: receiver user receive BDS system and gps system dual system separately satellite broadcast to the observation data of receiver user, specifically comprise:

The B2 frequency pseudorange observation data of BDS system and carrier phase observation data;

The L2 frequency pseudorange observation data of gps system and carrier phase observation data;

Step 2: determine BDS system B2 ambiguity of carrier phase and gps system L2 ambiguity of carrier phase respectively by carrier phase observation equation;

(1) for BDS system: the B2 frequency carrier Phase integer ambiguity being determined BDS system by formula (1), formula is:

LMC ₂·Φ _C2＝ρ _C+c·(t _r-t _Cs)-LMC ₂·N _C2+O _C-I _C2+T _C+M _C2+ε′ _C2(1)

In formula, LMC ₂it is the wavelength of BDS system B2 frequency carrier phase place; Φ _c2be BDS system B2 carrier phase observation data, subscript C represents BDS system; ρ _cfor BDS satellite is to the geometric distance of receiver, calculated by survey station initial position co-ordinates and BDS co-ordinates of satellite, wherein, survey station initial position co-ordinates is obtained by the pseudorange One-Point Location of single system, and co-ordinates of satellite is provided by the navigate file of receiver record; C is the light velocity in vacuum; t _rfor receiver clock-offsets, unit is second; t _csfor the clock correction of BDS system-satellite clock, in subscript, s represents satellite clock correction; N _c2it is the integer ambiguity of the B2 frequency carrier carrier phase observable of BDS system; O _cbDS system-satellite orbit error, the i.e. error of coordinate of the satellite position; I _c2it is the ionosphere delay error suffered by BDS system B2 frequency carrier carrier phase observable; T _cit is BDS system tropospheric delay error; M _c2for the multipath effect error of BDS system B2 frequency carrier carrier phase observable; ε _c2for BDS system B2 frequency carrier phase observations noise and non-model errors:

(2) for gps system: the L2 ambiguity of carrier phase being determined gps system by formula (2), formula is:

LMG ₂·Φ _G2＝ρ _G+c·(t _r-t _Gs)-LMG ₂·N _G2+O _G-I _G2+T _G+M _G2+ε′ _G2(2)

In formula, LMG ₂for the wavelength of gps system L2 frequency carrier phase place, Φ _g2be gps system L2 frequency carrier carrier phase observable, subscript G represents gps system; ρ _gfor gps satellite is to the geometric distance of receiver, calculated by survey station initial position co-ordinates and gps satellite coordinate, wherein survey station initial position co-ordinates is obtained by the pseudorange One-Point Location of single system, and co-ordinates of satellite is provided by the navigate file of receiver record; t _gsfor the clock correction of gps system satellite clock; N _g2it is the integer ambiguity of the L2 frequency carrier carrier phase observable of gps system; O _ggps system satellite orbital error, i.e. the error of coordinate of the satellite position; I _g2it is the ionosphere delay error suffered by gps system L2 frequency carrier carrier phase observable; T _git is gps system tropospheric delay error; M _g2for the multipath effect error of gps system L2 frequency carrier carrier phase observable; ε _g2for gps system L2 frequency carrier phase observations noise and non-model errors;

Step 3: with the coefficient of BDS system B2 frequency carrier phase wave length for difference blur level parameter between B2/L2 frequency carrier phase mixing star, or with the coefficient of gps system B2 frequency carrier phase wave length for difference blur level parameter between B2/L2 frequency carrier phase mixing star, the two optional one recovers the integer characteristic of difference blur level parameter between BDS system and gps system B2/L2 frequency carrier phase mixing star;

Wherein, with the coefficient of BDS system B2 frequency carrier phase wave length for difference blur level parameter between B2/L2 frequency carrier phase mixing star, the integer characteristic recovering difference blur level parameter between BDS system and gps system B2/L2 frequency carrier phase mixing star comprises the following steps:

Step 3.1: the non-mistake difference correction COR of the BDS system B2 frequency carrier phase place utilizing external reference station to provide _c2, gps system L2 frequency carrier phase place non-mistake difference correction COR _g2, revise the formula (1) in step 2 and formula (2), eliminate tropospheric delay error, ionosphere delay error, satellite orbital error and satellite clock error, concrete formula is as follows:

For BDS system, the formula after round-off error is:

LMC ₂·Φ _C2+COR _C2＝ρ _C+c·t _r-LMC ₂·N _C2+M _C2+ε′ _C2(3)

In formula, ε ' _c2for the observation noise of BDS system B2 frequency carrier phase place;

For gps system, the concrete formula after round-off error is:

LMG ₂·Φ _G2+COR _G2＝ρ _G+c·t _r-LMG ₂·N _G2+M _G2+ε′ _G2(4)

In formula, ε ' _g2for the observation noise of gps system L2 frequency carrier phase place;

Difference between mixing star is carried out, to eliminate the receiver clock-offsets t in formula (3) and formula (4) between step 3.2:BDS system B2 frequency carrier carrier phase observable and gps system L2 frequency carrier carrier phase observable _r, concrete formula is:

Carry out difference between mixing star between BDS system and gps system B2/L2 frequency carrier carrier phase observable, concrete formula is:

LMC ₂·Φ _C2-LMG ₂·Φ _G2+COR _C2-COR _G2＝ρ _C-ρ _G-(LMC ₂·N _C2-LMG ₂·N _G2)

(5)

LMC on the right side of formula (5) equation ₂n _c2-LMG ₂n _g2item represents the B2/L2 frequency carrier phase ambiguity of BDS system and gps system;

The form of integer reduction less to the B2/L2 frequency carrier phase ambiguity B2 frequency of BDS system and gps system, L2 frequency carrier phase ambiguity integer initial value and numerical value represented, formula is:

${\mathrm{LMC}}_2\·N_{C2}-{\mathrm{LMG}}_2\·N_{G2}={\mathrm{LMC}}_2\·N_{C2}^0-{\mathrm{LMG}}_2\·N_{G2}^0+({\mathrm{LMC}}_2\·N_{C2}^{\′}-{\mathrm{LMG}}_2\·N_{G2}^{\′})---\left(6\right)$

In formula, for the initial integer solution of BDS system B2 frequency carrier phase ambiguity, for the initial integer solution of the L2 frequency carrier phase ambiguity of gps system; N ' _c2for the integer reduction of BDS system B2 frequency carrier Phase integer ambiguity, N ' _g2for the integer reduction of gps system L2 frequency carrier phase ambiguity, the size of the integer reduction of B2/L2 frequency carrier phase ambiguity is relevant with the integer initial value of blur level;

Formula (6) is processed further, by the integer reduction N ' of the B2 carrier phase ambiguity of the satellite of in BDS system _c2, a satellite in gps system the integer reduction N ' of L2 frequency carrier phase ambiguity _g2form a blur level parameter by difference between star, then with the B2 carrier phase ambiguity wavelength of BDS system for coefficient, change into difference B2/L2 frequency carrier phase ambiguity between star, formula is:

${\mathrm{LMC}}_2\·N_{C2}-{\mathrm{LMG}}_2\·N_{G2}={\mathrm{LMC}}_2\·N_{C2}^0-{\mathrm{LMG}}_2\·N_{G2}^0+{\mathrm{LMC}}_2\·(N_{C2}^{\′}-\frac{{\mathrm{LMG}}_2}{{\mathrm{LMC}}_2}\·N_{G2}^{\′})---\left(7\right)$

Step 3.3: recover difference B2/L2 frequency carrier phase ambiguity parameter between star integer characteristic, detailed process is:

BDS system is different with B2, L2 frequency carrier phase wave length of gps system, and ask for wavelength ratio, formula is:

$\frac{{\mathrm{LMG}}_2}{{\mathrm{LMC}}_2}=A---\left(8\right)$

In formula, A represents B2 frequency, the L2 frequency carrier phase wave length ratio of gps system and BDS system, and has A ∈ (0,1);

Single poor B2/L2 carrier phase ambiguity parameter between the star then in formula (7) replace with further:

$N_{C2}^{\′}-\frac{{\mathrm{LMG}}_2}{{\mathrm{LMC}}_2}\·N_{G2}^{\′}=N_{C2}^{\′}-A\·N_{G2}^{\′}=N_{C2}^{\′}-N_{G2}^{\′}+(1-A)\·N_{G2}^{\′}---\left(9\right)$

In formula, N ' _c2with N ' _g2be all unknown complete cycle number, i.e. N ' _c2-N ' _g2for differentiated blur level parameter between BDS system and gps system B2/L2 frequency carrier phase mixing star, (1-A) N ' _g2be single poor blur level Parameter N between B2/L2 frequency carrier phase mixing star ' _c2-N ' _g2residual error item, formula (5) is then had:

$\begin{array}{c}{\mathrm{LMC}}_2\·{\mathrm{\Φ}}_{C2}-{\mathrm{LMG}}_2\·{\mathrm{\Φ}}_{G2}+{\mathrm{COR}}_{C2}-{\mathrm{COR}}_{G2}\\ ={\mathrm{\ρ}}_C-{\mathrm{\ρ}}_G-({\mathrm{LMC}}_2\·N_{C2}^0-{\mathrm{LMG}}_2\·N_{G2}^0+{\mathrm{LMC}}_2\·(N_{C2}^{\′}-\frac{{\mathrm{LMG}}_2}{{\mathrm{LMC}}_2}\·N_{G2}^{\′}))\\ ={\mathrm{\ρ}}_C-{\mathrm{\ρ}}_G-({\mathrm{LMC}}_2\·N_{C2}^0-{\mathrm{LMG}}_2\·N_{G2}^0+{\mathrm{LMC}}_2\·(N_{C2}^{\′}-N_{G2}^{\′}-(A-1)\·N_{G2}^{\′}))\end{array}---\left(10\right)$

Step 3.4: the integer initial value determining gps system L2 frequency carrier phase ambiguity, makes residual error item eliminate, and recovers B2/L2 frequency carrier phase ambiguity integer characteristic;

For current gps system, when the absolute value of residual error item value is less than 0.5:

If utilize the Pseudo-range Observations of gps system L2 frequency to calculate L2 frequency carrier phase ambiguity integer initial value, then the deviation of GPSL2 carrier phase ambiguity integer initial value should be less than 30 weeks;

When the absolute value of residual error item value is less than 0.25:

If the Pseudo-range Observations of the Pseudo-range Observations of gps system L2 frequency calculates L2 frequency carrier phase ambiguity integer initial value, then the deviation of gps system L2 frequency carrier phase ambiguity initial value should be less than 15 weeks;

For the above-mentioned situation with different residual error item, in BDS system and gps system B2/L2 frequency carrier phase ambiguity initial value accuracy rating, also eliminate residual error item, then formula (10) abbreviation is:

$\begin{array}{c}{\mathrm{LMC}}_2\·{\mathrm{\Φ}}_{C2}-{\mathrm{LMG}}_2\·{\mathrm{\Φ}}_{G2}+{\mathrm{COR}}_{C2}-{\mathrm{COR}}_{G2}\\ ={\mathrm{\ρ}}_C-{\mathrm{\ρ}}_G-({\mathrm{LMC}}_2\·N_{C2}^0-{\mathrm{LMG}}_2\·N_{G2}^0+{\mathrm{LMC}}_2\·(N_{C2}^{\′}-N_{G2}^{\′}))\end{array}---\left(11\right)$

In formula, N ' _c2-N ' _g2for the integer ambiguity of difference between B2/L2 frequency carrier phase mixing star, integer ambiguity Parameter N now ' _c2-N ' _g2resolve identical with traditional baseline Ambiguity Solution Methods;

With gps system L2 carrier phase wavelength for difference blur level parameter coefficient between B2/L2 frequency carrier phase mixing star, and recover the integer characteristic of difference blur level parameter between B2/L2 frequency carrier phase mixing star, comprise the following steps:

Step 3.5: process further formula (6), by the integer reduction N ' of the B2 frequency carrier phase ambiguity of a BDS system satellite _c2with the integer reduction N ' of the L2 frequency carrier phase ambiguity of a gps system satellite _g2, by being combined into a B2/L2 frequency carrier phase ambiguity after difference between mixing star, and with the L2 frequency carrier phase ambiguity wavelength of gps system for coefficient, form difference blur level between B2/L2 frequency carrier phase mixing star, formula is as follows:

${\mathrm{LMC}}_2\·N_{C2}-{\mathrm{LMG}}_2\·N_{G2}={\mathrm{LMC}}_2\·N_{C2}^0-{\mathrm{LMG}}_2\·N_{G2}^0+{\mathrm{LMG}}_2\·(\frac{{\mathrm{LMC}}_2}{{\mathrm{LMG}}_2}\·N_{C2}^{\′}-N_{G2}^{\′})---\left(12\right)$

In formula, for the blur level parameter that difference between BDS system and gps system B2/L2 frequency carrier phase mixing star combines,

Step 3.6: recover difference B2/L2 frequency carrier phase ambiguity parameter between star integer characteristic, detailed process is:

B2 frequency, the L2 frequency carrier phase wave length of BDS system and gps system are different, and ask for wavelength ratio, formula is:

$\frac{{\mathrm{LMC}}_2}{{\mathrm{LMG}}_2}=B---\left(13\right)$

In formula, B represents B2 frequency, the L2 frequency carrier phase wave length ratio of BDS system and gps system, and has B ∈ (1,2);

According to formula (13), then single poor blur level between the B2/L2 frequency carrier phase mixing star in formula (12) write as further:

$\frac{{\mathrm{LMC}}_2}{{\mathrm{LMG}}_2}\·N_{C2}^{\′}-N_{G2}^{\′}={\mathrm{BN}}_{C2}^{\′}-N_{G2}^{\′}=N_{C2}^{\′}-N_{G2}^{\′}-(1-B)\·N_{C2}^{\′}---\left(14\right)$

In formula, (1-B) N ' _c2for complete cycle number N ' _c2-N ' _g2residual error item, formula (5) is then had:

$\begin{array}{c}{\mathrm{LMC}}_2\·{\mathrm{\Φ}}_{C2}-{\mathrm{LMG}}_2\·{\mathrm{\Φ}}_{G2}+{\mathrm{COR}}_{C2}-{\mathrm{COR}}_{G2}\\ ={\mathrm{\ρ}}_C-{\mathrm{\ρ}}_G-({\mathrm{LMC}}_2\·N_{C2}^0-{\mathrm{LMG}}_2\·N_{G2}^0+{\mathrm{LMG}}_2\·(\frac{{\mathrm{LMC}}_2}{{\mathrm{LMG}}_2}\·N_{C2}^{\′}-N_{G2}^{\′}))\\ ={\mathrm{\ρ}}_C-{\mathrm{\ρ}}_G-({\mathrm{LMC}}_2\·N_{C2}^0-{\mathrm{LMG}}_2\·N_{G2}^0+{\mathrm{LMG}}_2\·(N_{C2}^{\′}-N_{G2}^{\′}+(B-1)\·N_{C2}^{\′}))\end{array}---\left(15\right)$

If to make between B2/L2 frequency carrier phase mixing star single poor blur level Parameter N ' _c2-N ' _g2recover integer characteristic, so that carry out single poor Carrier Phase Ambiguity Resolution between B2/L2 frequency carrier phase mixing star, need residual error item (B-1) N ' _c2impact be reduced to and do not affect N ' _c2-N ' _g2complete cycle characteristic;

Step 3.7: the integer initial value arranging BDS system B2 frequency carrier phase ambiguity, makes residual error item eliminate, and recovers B2 carrier phase ambiguity integer characteristic;

Utilize the Pseudo-range Observations of BDS system B2 frequency to calculate the initial value of BDS system B2 frequency carrier phase ambiguity, the minimum requirements that initial value should meet is:

For current BDS system, when the absolute value of residual error item value is less than 0.5:

If utilize the Pseudo-range Observations of BDS system B2 frequency to calculate B2 carrier phase ambiguity integer initial value, then the deviation of BDS system B2 frequency carrier phase ambiguity initial value should be less than 30 weeks;

When the absolute value of residual error item value is less than 0.25:

If utilize the Pseudo-range Observations of BDS system B2 frequency to calculate B2 carrier phase ambiguity integer initial value, then the deviation of BDS system B2 frequency carrier phase ambiguity initial value should be less than 15 weeks.

For the above-mentioned situation with different residual error item, in BDS system B2 frequency carrier phase ambiguity initial value accuracy rating, also eliminate residual error item, then formula (15) namely has:

$\begin{array}{c}{\mathrm{LMC}}_2\·{\mathrm{\Φ}}_{C2}-{\mathrm{LMG}}_2\·{\mathrm{\Φ}}_{G2}+{\mathrm{COR}}_C-{\mathrm{COR}}_G\\ ={\mathrm{\ρ}}_C-{\mathrm{\ρ}}_G-({\mathrm{LMC}}_2\·N_{C2}^0-{\mathrm{LMG}}_2\·N_{G2}^0+{\mathrm{LMG}}_2\·(N_{C2}^{\′}-N_{G2}^{\′}))\end{array}---\left(16\right)$

In formula, N ' _c2-N ' _g2difference integer ambiguity parameter between the B2/L2 frequency carrier phase mixing star being observation equation (16), integer ambiguity N ' now _c2-N ' _g2resolve identical with traditional baseline Ambiguity Solution Methods;

Step 4: B2/L2 frequency carrier carrier phase observable mixing difference integer ambiguity N ' between star _c2-N ' _g2after determining, formula (11) or formula (16) is utilized to calculate survey station location parameter, then the initial integer solution of BDS system B2 frequency carrier phase ambiguity and gps system L2 frequency carrier phase ambiguity is calculated again by survey station location parameter, namely the integer ambiguity determined is utilized to carry out the iterative computation of the initial integer solution of blur level, determine difference integer ambiguity between final B2/L2 frequency carrier phase place star, between recycling B2/L2 frequency carrier phase place star, between differential carrier phase observed reading and B2/L2 frequency carrier phase place star, difference blur level determines that user BDS/GPS receiver is to satellite distance.

Beneficial effect of the present invention: mixing difference method between the B2/L2 carrier phase star of a kind of BDS and GPS.The method to be carried out between mixing star after difference combines in BDS system and gps system B2 frequency, L2 frequency carrier carrier phase observable, by the calculating of BDS system and gps system single satellite B2 frequency, L2 frequency carrier phase ambiguity initial value, observation equation between the star of BDS system and gps system B2/L2 frequency carrier phase place is converted, with the reduction of BDS system and gps system B2/L2 frequency carrier phase ambiguity initial value for B2/L2 frequency carrier phase ambiguity parameter.The impact that BDS system B2 carrier phase is different from both gps system L2 carrier phases frequency can be avoided, make the blur level Parameter reconstruction integer characteristic of difference between B2/L2 frequency carrier phase mixing star.Can when BDS system and gps system single system observation satellite negligible amounts, the receiver error in BDS system and gps system B2 frequency, L2 frequency carrier carrier phase observable can be eliminated by difference between star.Can provide condition precedent for poor resolving real-time of B2/L2 frequency carrier phase ambiguity single between star again, namely between star, single poor B2/L2 frequency carrier phase ambiguity parameter has integer characteristic.The present invention carries out difference between star to different system different frequency B2 frequency, L2 frequency carrier phase place, keep the integer characteristic of difference B2 frequency, L2 frequency carrier phase ambiguity parameter between dual system star, when can solve BDS system and gps system single system observation satellite number deficiency, B2, L2 single-frequency carrier phase observation data how is utilized to realize the problem of Dynamic High-accuracy location.

Accompanying drawing explanation

Fig. 1 be embodiment of the present invention BDS and GPS B2/L2 carrier phase star between mixing difference method process flow diagram;

Fig. 2 is the time series schematic diagram of the L2 carrier phase ambiguity integer initial value of embodiment of the present invention gps system G05 satellite;

Fig. 3 is embodiment of the present invention residual error 0.01664N ' _g2value schematic diagram;

Fig. 4 is receiver location after embodiment of the present invention calculates and the difference schematic diagram of known receiver actual coordinate.

Embodiment

Below in conjunction with accompanying drawing, embodiments of the present invention are described in further detail.

A mixing difference method between the B2/L2 carrier phase star of BDS and GPS, its flow process as shown in Figure 1, comprises the following steps:

Step 1: receiver user receive BDS system and gps system dual system separately satellite broadcast to the observation data of receiver user, specifically comprise:

The pseudorange observation data of the B2 frequency of BDS system and carrier phase observation data.The Pseudo-range Observations of B2 frequency is used for the calculating of BDS system B2 carrier phase ambiguity initial value integer solution.

The pseudorange observation data of the L2 frequency of gps system and carrier phase observation data.The Pseudo-range Observations of L2 frequency is used for the calculating of gps system L2 carrier phase ambiguity initial value integer solution.

The frequency of the B2 carrier phase of BDS system is 1207.140MHz, and the L2 carrier phase frequency of gps system is 1227.60MHz, and the two frequency is comparatively close, but different.The wavelength of BDS system B2 carrier phase is 0.24834 meter, and the wavelength of gps system L2 carrier phase is 0.24421 meter.

Step 2: determine the ambiguity of carrier phase of BDS system B2 frequency and the ambiguity of carrier phase of gps system L2 frequency;

(1) for BDS system: by the carrier phase observation equation of BDS system B2 frequency, determine the B2 frequency carrier Phase integer ambiguity of BDS system, the formula of BDS system B2 frequency carrier phase observations equation is:

LMC ₂·Φ _C2＝ρ _C+c·(t _r-t _Cs)-LMC ₂·N _C2+O _C-I _C2+T _C+M _C2+ε′ _C2(1)

In formula, LMC ₂it is the wavelength of BDS system B2 frequency carrier phase place; Φ _c2be BDS system B2 frequency carrier carrier phase observable, subscript C represents BDS system; ρ _cfor BDS satellite is to the geometric distance of receiver, calculated by survey station initial position co-ordinates and BDS co-ordinates of satellite, wherein, the initial position co-ordinates of survey station receiver antenna phase center is obtained by the pseudorange One-Point Location of gps system, co-ordinates of satellite, by the broadcast ephemeris in the BDS system navigate file of receiver record, utilizes Orbit extrapolation to determine by Kepler six parameter; C is the light velocity in vacuum; t _rfor receiver clock-offsets, the difference namely between time of receiver clock hourly observation data and BDS system time, unit is second; t _csfor the clock correction of BDS system-satellite clock, in subscript, s represents satellite clock correction, is the difference between BDS satellite clock and BDS system time; LMC ₂for the wavelength of BDS system B2 frequency carrier phase place; N _c2it is BDS system B2 frequency carrier Phase integer ambiguity; O _cbDS system-satellite orbit error, the BDS system-satellite position coordinates namely calculated by broadcast ephemeris and the difference of satellite actual position coordinate; I _c2it is the ionosphere delay error suffered by BDS system B2 frequency carrier carrier phase observable; T _cit is BDS system tropospheric delay error; M _c2for the multipath effect error of BDS system B2 frequency carrier carrier phase observable; ε _c2for BDS system B2 frequency carrier phase observations noise and non-model errors;

(2) for gps system: by the carrier phase observation equation of gps system L2 frequency, determine the L2 ambiguity of carrier phase of gps system, the formula of gps system L2 carrier phase observation equation is:

LMG ₂·Φ _G2＝ρ _G+c·(t _r-t _Gs)-LMG ₂·N _G2+O _G-I _G2+T _G+M _G2+ε′ _G2(2)

In formula, LMG ₂for the wavelength of gps system L2 frequency carrier phase place, Φ _g2be gps system L2 frequency carrier carrier phase observable, subscript G represents gps system; ρ _gfor gps satellite is to the geometric distance of receiver, calculated by survey station initial position co-ordinates and gps satellite coordinate, wherein survey station initial position co-ordinates is obtained by the pseudorange One-Point Location of gps system, co-ordinates of satellite, by the broadcast ephemeris in the gps system navigate file of receiver record, is determined by the Orbit extrapolation of Kepler six parameter; t _rfor receiver clock-offsets, be the difference between the time of receiver clock record and BDS system time, unit is second herein; t _gsfor the clock correction of gps system satellite clock, for gps satellite clock and the difference of gps system time, be as the criterion with the gps system time when gps system observation data obtains, gps system time and BDS system time are unified by present embodiment after gps system observation data obtains, and convert to BDS system time as benchmark; N _g2it is the integer ambiguity of the carrier phase observation data of gps system L2 frequency; O _ggps system satellite orbital error, the gps system coordinate of the satellite position namely calculated by broadcast ephemeris and the difference of satellite actual position coordinate; I _g2it is the ionosphere delay error suffered by gps system L2 frequency carrier carrier phase observable; T _git is the tropospheric delay error of gps system satellite; M _g2for the multipath effect error of gps system L2 frequency carrier carrier phase observable; ε _g2for gps system L2 frequency carrier phase observations noise and non-model errors;

Step 3: the coefficient being difference B2/L2 frequency carrier phase ambiguity parameter between star with BDS system B2 frequency carrier phase wave length or gps system L2 carrier phase wavelength, build the observation equation of mixing difference between BDS system and gps system B2/L2 frequency carrier phase place star, and recover the integer characteristic of mixing difference blur level parameter between B2/L2 frequency carrier phase place star, allow to realize resolving of mixing difference integer ambiguity between BDS system and gps system B2/L2 frequency carrier phase place star.Respectively with BDS system B2 carrier phase wavelength and gps system L2 frequency carrier phase wave length one of them for coefficient, recover the integer characteristic of mixing difference blur level parameter between BDS system and gps system B2/L2 frequency carrier phase place star;

Wherein, with the coefficient of BDS system B2 frequency carrier phase wave length for mixing difference blur level parameter between B2/L2 frequency carrier phase place star, the integer characteristic recovering mixing difference blur level parameter between BDS system and gps system B2/L2 frequency carrier phase place star comprises the following steps:

Step 3.1: the non-mistake difference correction COR of the BDS system B2 frequency carrier phase place utilizing external reference station to provide _c2, gps system L2 frequency carrier phase place non-mistake difference correction COR _g2, error correction is carried out to the formula (1) in step 2 and formula (2).If use an external reference station, the Correction of Errors information needed for subscriber station is obtained according to a reference station observation data, if use multiple external reference station, according to the position of multiple reference station relative to subscriber station and the Correction of Errors information of each reference station, utilize the Correction of Errors information that the method for error interpolation matching obtains needed for subscriber station.The Correction of Errors information provided by utilizing external reference station, the impact of formula (1) and formula (2) tropospheric delay error, ionosphere delay error, satellite orbital error and satellite clock error in removal process 2, concrete formula is as follows:

For BDS system, the formula after B2 frequency carrier phase observations equation round-off error is:

LMC ₂·Φ _C2+COR _C2＝ρ _C+c·t _r-LMC ₂·N _C2+M _C2+ε′ _C2(3)

In formula, ε ' _c2for the observation noise of BDS system B2 frequency carrier phase place.

For gps system, after L2 frequency carrier phase observations equation round-off error, formula is:

LMG ₂·Φ _G2+COR _G2＝ρ _G+c·t _r-LMG ₂·N _G2+M _G2+ε′ _G2(4)

In formula, ε ' _g2for the observation noise of gps system L2 frequency carrier phase place.

In the revised B2 frequency of non-mistake difference correction, L2 frequency carrier phase observations equation formulations (3), formula (4), eliminate the impact of tropospheric delay error, ionosphere delay error, satellite orbital error, gps satellite clock correction and BDS system-satellite clock correction.But still comprising the impact of receiver clock-offsets and observation noise, the observation noise of B2 frequency, L2 frequency carrier phase place is very little, can ignore its impact on B2/L2 frequency carrier phase ambiguity.Then the receiver clock-offsets in formula (3), formula (4) is eliminated by difference between BDS system B2 carrier phase and gps system L2 carrier phase mixing star.

Step 3.2:BDS system B2 frequency carrier phase observations equation and gps system L2 frequency carrier phase observations equation carry out difference between mixing star, to eliminate the receiver clock-offsets t in formula (3) and formula (4) _r, concrete formula is:

LMC ₂·Φ _C2-LMG ₂·Φ _G2+COR _C2-COR _G2＝ρ _C-ρ _G-(LMC ₂·N _C2-LMG ₂·N _G2)

(5)

LMC on the right side of formula (5) equation ₂n _c2-LMG ₂n _g2to represent the blur level of difference between BDS system and gps system B2 frequency, L2 frequency carrier phase mixing star, formula (5) is the observation equation of difference between BDS system B2 frequency carrier phase place and gps system L2 frequency carrier phase mixing star;

By difference blur level LMC between BDS system and gps system B2/L2 frequency carrier phase mixing star ₂n _c2-LMG ₂n _g2represent by the form of B2, L2 carrier phase ambiguity integer initial value and an integer reduction, formula is:

${\mathrm{LMC}}_2\·N_{C2}-{\mathrm{LMG}}_2\·N_{G2}={\mathrm{LMC}}_2\·N_{C2}^0-{\mathrm{LMG}}_2\·N_{G2}^0+({\mathrm{LMC}}_2\·N_{C2}^{\′}-{\mathrm{LMG}}_2\·N_{G2}^{\′})---\left(6\right)$

In formula, for the initial integer solution of BDS system B2 frequency carrier phase ambiguity, for the initial integer solution of gps system L2 frequency carrier phase ambiguity; N ' _c2for the integer reduction of BDS system B2 frequency carrier Phase integer ambiguity, N ' _g2for the integer reduction of gps system L2 frequency carrier phase ambiguity.The size of the integer reduction of B2 frequency, L2 frequency carrier phase ambiguity is relevant with the integer initial value of B2 frequency, L2 frequency carrier phase ambiguity, i.e. integer reduction N ' _c2, N ' _g2for B2 frequency, L2 frequency carrier phase ambiguity integer initial value precision.Present embodiment is by controlling integer reduction N ' _c2, N ' _g2numerical values recited recover the integer characteristic of difference blur level between BDS system and gps system B2/L2 frequency mixing star.Integer reduction N ' _c2, N ' _g2numerical value must be less;

Calculating the B2 frequency carrier phase ambiguity integer initial value of BDS system with the L2 frequency carrier phase ambiguity integer initial value of gps system when, B2 frequency, L2 frequency carrier phase ambiguity integer initial value namely as given value, the integer reduction N ' in formula (6) _c2, N ' _g2become the B2 frequency in formula (5), L2 frequency carrier Phase integer ambiguity parameter.By the integer reduction N ' of the B2 frequency carrier phase ambiguity of the satellite of in BDS system _c2, a satellite in gps system the integer reduction N ' of L2 frequency carrier phase ambiguity _g2form a B2/L2 frequency carrier phase ambiguity parameter by difference between star, and with BDS system B2 frequency carrier phase ambiguity wavelength for coefficient, formula is:

${\mathrm{LMC}}_2\·N_{C2}-{\mathrm{LMG}}_2\·N_{G2}={\mathrm{LMC}}_2\·N_{C2}^0-{\mathrm{LMG}}_2\·N_{G2}^0+{\mathrm{LMC}}_2\·(N_{C2}^{\′}-\frac{{\mathrm{LMG}}_2}{{\mathrm{LMC}}_2}\·N_{G2}^{\′})---\left(7\right)$

Then formula (5) is had:

$\begin{array}{c}{\mathrm{LMC}}_2\·{\mathrm{\Φ}}_{C2}-{\mathrm{LMG}}_2\·{\mathrm{\Φ}}_{G2}+{\mathrm{COR}}_{C2}-{\mathrm{COR}}_{G2}\\ ={\mathrm{\ρ}}_C-{\mathrm{\ρ}}_G-({\mathrm{LMC}}_2\·N_{C2}^0-{\mathrm{LMG}}_2\·N_{G2}^0+{\mathrm{LMC}}_2\·(N_{C2}^{\′}-\frac{{\mathrm{LMG}}_2}{{\mathrm{LMC}}_2}\·N_{G2}^{\′}))\end{array}---\left(8\right)$

Step 3.3: difference blur level parameter between the observation equation formula (8) of difference middle B2/L2 frequency carrier phase mixing star between recovery BDS system B2 frequency carrier phase place and gps system L2 frequency carrier phase mixing star integer characteristic, detailed process is:

BDS system B2 frequency carrier phase place is different with gps system L2 frequency carrier phase wave length, due to, the B2 frequency carrier phase wave length LMG of BDS system ₂=0.24421 meter, the L2 frequency carrier phase wave length LMC of gps system ₂=0.24834 meter.Ask gps system L2 frequency carrier phase ambiguity Parameter N in formula (8) ' _g2coefficient the i.e. wavelength ratio of BDS system B2 frequency carrier phase place and gps system L2 frequency carrier phase place, then have:

$\frac{{\mathrm{LMG}}_2}{{\mathrm{LMC}}_2}=0.98336---\left(9\right)$

In formula, $\frac{{\mathrm{LMG}}_2}{{\mathrm{LMC}}_2}=A\∈\left(\mathrm{0,1}\right)$

Then for formula (7), mixing list difference blur level Parameter N between B2/L2 frequency carrier phase place star wherein ' _c2-0.98336N ' _g2replace with further:

$N_{C2}^{\′}-\frac{{\mathrm{LMG}}_2}{{\mathrm{LMC}}_2}\·N_{G2}^{\′}=N_{C2}^{\′}-0.98336\·N_{G2}^{\′}=N_{C2}^{\′}-N_{G2}^{\′}+0.01664\·N_{G2}^{\′}---\left(10\right)$

In formula, B2 frequency carrier phase ambiguity integer initial value integer reduction N ' _c2with L2 frequency carrier phase ambiguity integer initial value integer reduction N ' _g2be all unknown complete cycle number, that is N ' _c2-N ' _g2for the differentiated blur level parameter of mixing between BDS system and gps system B2/L2 frequency carrier phase place star, 0.01664N ' _g2be mixing difference blur level Parameter N between B2/L2 frequency carrier phase place star ' _c2-N ' _g2residual error item, formula (8) is then had:

$\begin{array}{c}{\mathrm{LMC}}_2\·{\mathrm{\Φ}}_{C2}-{\mathrm{LMG}}_2\·{\mathrm{\Φ}}_{G2}+{\mathrm{COR}}_{C2}-{\mathrm{COR}}_{G2}\\ ={\mathrm{\ρ}}_C-{\mathrm{\ρ}}_G-({\mathrm{LMC}}_2\·N_{C2}^0-{\mathrm{LMG}}_2\·N_{G2}^0+{\mathrm{LMC}}_2\·(N_{C2}^{\′}-N_{G2}^{\′}+0.01664\·N_{G2}^{\′}))\end{array}---\left(11\right)$

Step 3.4: the integer initial value determining gps system L2 frequency carrier phase ambiguity, makes residual error item 0.01664N ' _g2not affect in formula (11) resolving of mixing difference blur level parameter between B2/L2 frequency carrier phase place star, i.e. residual error item 0.01664N ' _g2size can recover and keep mixing difference blur level Parameter N between B2/L2 frequency carrier phase place star ' _c2-N ' _g2integer characteristic;

Residual error item 0.01664N ' _g2when the absolute value of value is less than 0.5, residual error item 0.01664N ' _g2do not affect resolving of mixing difference blur level parameter between B2/L2 frequency carrier phase place star, the integer characteristic of mixing difference blur level parameter between B2/L2 frequency carrier phase place star can be recovered:

For current gps system, present embodiment utilizes the GPS Pseudo-range Observations of L2 frequency to calculate the integer initial value of L2 carrier phase ambiguity.The formula of the observation equation of GPS Pseudo-range Observations after the non-poor Correction of Errors in external reference station is:

P _G2+COR _GP2＝ρ _G+c·t _r+M _GP2+ε′ _GP2(12)

In formula, P _g2for the Pseudo-range Observations of gps system L2 frequency; COR _gP2for the non-mistake difference correction of L2 frequency Pseudo-range Observations, provided by external reference station, identical with the source of the non-mistake difference correction of receiver user in step 3.1; ρ _gfor gps satellite is to the geometric distance of receiver, t _rfor receiver clock-offsets, unit is second, and the implication of the two is identical with formula (2); M _gP2for the multipath effect error of gps system L2 frequency Pseudo-range Observations; ε ' _gP2for gps system L2 frequency s pseudorange observation noise and non-model errors.

Utilize the Pseudo-range Observations of gps system L2 frequency after the non-mistake difference correction correction of external reference station, calculate the integer initial value of L2 carrier phase ambiguity.According to formula (4), formula (12), ignore multipath effect, observation noise and non-model errors, calculate the integer initial value of L2 carrier phase ambiguity formula be:

$N_{G2}^0=\mathrm{INT}(P_{G2}/{\mathrm{LMG}}_2+{\mathrm{COR}}_{\mathrm{GP}2}/{\mathrm{LMG}}_2-{\mathrm{COR}}_{G2}/{\mathrm{LMG}}_2-{\mathrm{\Φ}}_{G2})---\left(13\right)$

In formula, INT is round numbers symbol, gets its immediate integer by the value in bracket on the right side of equation.The precision that use formula (13) calculates L2 frequency carrier phase ambiguity integer initial value depends primarily on gps system L2 frequency Pseudo-range Observations P _g2precision.For current gps system, when the absolute value of residual error item value is less than 0.25:

The integer reduction N ' of the gps system L2 frequency carrier phase ambiguity initial value utilizing formula (13) to calculate _g2absolute value should be less than 15 weeks, the equivalent distances precision of Pseudo-range Observations is about 3.66 meters, i.e. 0.25 < 0.01664N ' _g2< 0.25, does not affect blur level N ' _c2-N ' _g2integer characteristic;

When the absolute value of residual error item value is less than 0.5:

If there is rough error in gps system L2 frequency Pseudo-range Observations, then the gps system L2 frequency carrier phase ambiguity initial value utilizing formula (13) to calculate the absolute value of integer reduction should be less than 30 weeks, namely integer reduction N ' _g2absolute value be less than 28, the equivalent distances precision of Pseudo-range Observations is 7.3 meters, i.e. residual error item-0.5 < 0.01664N ' _g2< 0.5, does not affect blur level N ' _c2-N ' _g2integer characteristic.Generally, for current gps system, the rough error of the gps system L2 frequency Pseudo-range Observations in formula (13) can meet this accuracy requirement;

Utilize the Pseudo-range Observations of gps system L2 frequency to calculate the integer initial value of L2 frequency carrier phase ambiguity, use two kinds of methods.A kind of integer initial value being the Pseudo-range Observations of an epoch of use and calculating L2 frequency carrier phase ambiguity, the mainly observation noise impact of Pseudo-range Observations, but for gps system, the precision of above-mentioned L2 frequency carrier phase ambiguity initial value can meet completely.This method utilizes the Pseudo-range Observations of an epoch to calculate the integer initial value of L2 frequency carrier phase ambiguity by formula (13); The second is the precision calculating the integer initial value of L2 frequency carrier phase ambiguity in order to improve Pseudo-range Observations, before using current epoch, the Pseudo-range Observations of multiple epoch calculates the integer initial value of L2 frequency carrier phase ambiguity, then the integer initial value of multiple identical L2 frequency carrier phase ambiguity is averaged, to improve the precision of L2 frequency carrier phase ambiguity integer initial value, namely utilize the Pseudo-range Observations of same satellite multiple epoch to be calculated the initial value of L2 frequency ambiguity degree by formula (13), then be averaged.

For gps system, the precision of above-mentioned L2 frequency carrier phase ambiguity initial value can meet completely.For the above-mentioned situation with different residual error item, in L2 frequency carrier phase ambiguity initial value accuracy rating, also eliminate residual error item, then formula (11) abbreviation is:

$\begin{array}{c}{\mathrm{LMC}}_2\&CenterDot;{\mathrm{\&Phi;}}_{C2}-{\mathrm{LMG}}_2\&CenterDot;{\mathrm{\&Phi;}}_{G2}+{\mathrm{COR}}_{C2}-{\mathrm{COR}}_{G2}\\ ={\mathrm{\&rho;}}_C-{\mathrm{\&rho;}}_G-({\mathrm{LMC}}_2\&CenterDot;N_{C2}^0-{\mathrm{LMG}}_2\&CenterDot;N_{G2}^0+{\mathrm{LMC}}_2\&CenterDot;(N_{C2}^{\&prime;}-N_{G2}^{\&prime;}))\end{array}---\left(14\right)$

In formula, N ' _c2-N ' _g2for the integer ambiguity of mixing difference combination between B2/L2 frequency carrier phase place star, the integer ambiguity Parameter N that between B2/L2 frequency carrier phase place star now, mixing difference combines ' _c2-N ' _g2resolve identical with traditional baseline Ambiguity Solution Methods;

The Pseudo-range Observations of Fig. 2 for utilizing formula (13) to use L2 frequency, calculate the time series of the L2 carrier phase ambiguity integer initial value of gps system G05 satellite, transverse axis represents that observation time is second in week, and the longitudinal axis represents blur level size, and unit is week.The observation duration of this group BDS system and gps system B2, L2 carrier phase observation data is about 3 hours.The exact value of the L2 carrier phase ambiguity of gps system G05 satellite is 1.The reduction N ' of blur level integer initial value is calculated according to the right value of the result in Fig. 2 and L2 carrier phase ambiguity _g2, and then calculating blur level Parameter N ' _c2-N ' _g2residual error 0.01664N ' _g2.Fig. 3 is residual error 0.01664N ' _g2value, transverse axis represents that observation time is second in week, and the longitudinal axis represents the size of residual error, and unit be all, residual error 0.01664N ' _g2the RMS of numerical value is 0.032 week, much smaller than 0.25 week, do not affect blur level Parameter N ' _c2-N ' _g2integer characteristic.Can by blur level Parameter N ' _c2-N ' _g2determine, and then calculate BDS system and gps system satellite to the distance of receiver, realize the position calculation of receiver user.

With the coefficient of gps system L2 frequency carrier phase wave length for mixing difference combinational fuzzy degree parameter between B2/L2 frequency carrier phase place star, and recover the integer characteristic of mixing difference combinational fuzzy degree parameter between B2/L2 frequency carrier phase place star, comprise the following steps:

Step 3.5: calculating the B2 frequency carrier phase ambiguity integer initial value of BDS system with the L2 frequency carrier phase ambiguity integer initial value of gps system when, B2 frequency, L2 frequency carrier phase place star blur level integer initial value namely as given value, the integer reduction N ' in formula (6) _c2, N ' _g2become two ambiguity of carrier phase parameters in formula (5).By the integer reduction N ' of the B2 frequency carrier phase ambiguity of a satellite in BDS system _c2, the integer reduction N ' of the L2 frequency carrier phase ambiguity of a satellite in gps system _g2synthesize a blur level parameter by differential set between mixing star, and with gps system L2 frequency carrier phase ambiguity wavelength for coefficient, formula is as follows:

${\mathrm{LMC}}_2\&CenterDot;N_{C2}-{\mathrm{LMG}}_2\&CenterDot;N_{G2}={\mathrm{LMC}}_2\&CenterDot;N_{C2}^0-{\mathrm{LMG}}_2\&CenterDot;N_{G2}^0+{\mathrm{LMG}}_2\&CenterDot;(\frac{{\mathrm{LMC}}_2}{{\mathrm{LMG}}_2}\&CenterDot;N_{C2}^{\&prime;}-N_{G2}^{\&prime;})---\left(15\right)$

Then formula (5) is had:

$\begin{array}{c}{\mathrm{LMC}}_2\&CenterDot;{\mathrm{\&Phi;}}_{C2}-{\mathrm{LMG}}_2\&CenterDot;{\mathrm{\&Phi;}}_{G2}+{\mathrm{COR}}_{C2}-{\mathrm{COR}}_{G2}\\ ={\mathrm{\&rho;}}_C-{\mathrm{\&rho;}}_G-({\mathrm{LMC}}_2\&CenterDot;N_{C2}^0-{\mathrm{LMG}}_2\&CenterDot;N_{G2}^0+{\mathrm{LMG}}_2\&CenterDot;(\frac{{\mathrm{LMC}}_2}{{\mathrm{LMG}}_2}\&CenterDot;{N_{C2}^{\&prime;}-N}_{G2}^{\&prime;}))\end{array}---\left(\text{16}\right)$

In formula (15), formula (16), for the blur level parameter that difference between BDS system and gps system B2/L2 frequency carrier phase mixing star combines.

Step 3.6: difference blur level parameter between observation equation formula (16) culminant star recovering difference between BDS system and gps system B2/L2 frequency carrier phase mixing star integer characteristic, detailed process is:

Due to, BDS system B2 carrier phase is different with gps system L2 frequency carrier phase wave length, the B2 frequency carrier phase wave length LMG of BDS system ₂=0.24421 meter, the L2 frequency carrier phase wave length LMC of gps system ₂=0.24834 meter.Institute is (16) middle blur level parameter with the formula not there is integer characteristic.By BDS system B2 frequency carrier phase place and gps system L2 frequency carrier phase wave length, ask B2 frequency carrier phase ambiguity Parameter N in formula (16) ' _c2coefficient the i.e. wavelength ratio of BDS system B2 frequency carrier phase place and gps system L2 frequency carrier phase place, then have:

$\frac{{\mathrm{LMC}}_2}{{\mathrm{LMG}}_2}=1.01691---\left(17\right)$

In formula, $\frac{{\mathrm{LMC}}_2}{{\mathrm{LMG}}_2}=B\&Element;\left(\mathrm{1,2}\right);$

According to formula (17), then mixing difference blur level between the B2/L2 frequency carrier phase place star in formula (15) write as further:

$\frac{{\mathrm{LMC}}_2}{{\mathrm{LMG}}_2}\&CenterDot;N_{C2}^{\&prime;}-N_{G2}^{\&prime;}={B\&CenterDot;N}_{C2}^{\&prime;}-N_{G2}^{\&prime;}=1.01691\&CenterDot;N_{C2}^{\&prime;}-N_{G2}^{\&prime;}=N_{C2}^{\&prime;}-N_{G2}^{\&prime;}+0.01691\&CenterDot;N_{C2}^{\&prime;}---\left(18\right)$

B2 carrier phase ambiguity integer initial value integer reduction N ' _c2with L2 frequency carrier phase ambiguity integer initial value integer reduction N ' _g2be all unknown complete cycle number, that is N ' _c2-N ' _g2for the differentiated blur level parameter of mixing between BDS system and gps system B2/L2 frequency carrier phase place star, 0.01691N ' _c2be difference blur level Parameter N between B2/L2 frequency carrier phase mixing star ' _c2-N ' _g2residual error item, formula (16) is then had:

$\begin{array}{c}{\mathrm{LMC}}_2\&CenterDot;{\mathrm{\&Phi;}}_{C2}-{\mathrm{LMG}}_2\&CenterDot;{\mathrm{\&Phi;}}_{G2}+{\mathrm{COR}}_{C2}-{\mathrm{COR}}_{G2}\\ ={\mathrm{\&rho;}}_C-{\mathrm{\&rho;}}_G-({\mathrm{LMC}}_2\&CenterDot;N_{C2}^0-{\mathrm{LMG}}_2\&CenterDot;N_{G2}^0+{\mathrm{LMG}}_2\&CenterDot;(N_{C2}^{\&prime;}-N_{G2}^{\&prime;}+0.01691\&CenterDot;N_{C2}^{\&prime;}))\end{array}---\left(19\right)$

If make difference blur level Parameter N between B2/L2 frequency carrier phase mixing star ' _c2-N ' _g2recover integer characteristic, so that carry out Carrier Phase Ambiguity Resolution, need residual error item 0.01691N ' _c2impact be reduced to and do not affect N ' _c2-N ' _g2complete cycle characteristic;

Step 3.7: the integer initial value determining BDS system B2 frequency carrier phase ambiguity, makes residual error item 0.01691N ' _c2do not affect resolving of the middle blur level parameter of formula (19), i.e. residual error item 0.01691N ' _c2size can recover and keep the integer characteristic of difference blur level parameter between B2/L2 frequency carrier phase mixing star;

Residual error item 0.01691N ' _c2when the absolute value of value is less than 0.5, residual error item 0.01691N ' _c2do not affect resolving of difference blur level between B2/L2 frequency carrier phase mixing star, the integer characteristic of difference blur level parameter between B2/L2 frequency carrier phase mixing star can be recovered:

For current BDS system, present embodiment utilizes the Pseudo-range Observations of BDS system B2 frequency to calculate the integer initial value of B2 carrier phase ambiguity.The formula of the observation equation of BDS system B2 frequency Pseudo-range Observations after the non-poor Correction of Errors in external reference station is:

P _C2+COR _CP2＝ρ _C+c·t _r+M _CP2+ε′ _CP2(20)

In formula, P _c2for the Pseudo-range Observations of BDS system B2 frequency; COR _cP2for the Correction of Errors number of B2 frequency Pseudo-range Observations, provided by external reference station, identical with the source of the non-mistake difference correction of receiver user in step 3.1; ρ _cfor BDS system-satellite is to the geometric distance of receiver, t _rfor receiver clock-offsets, unit is second, and the implication of the two is identical with formula (1); M _cP2for the multipath effect error of BDS system B2 frequency Pseudo-range Observations; ε ' _cP2for BDS system B2 frequency pseudorange observation noise and non-model errors.

Utilize the BDS system Pseudo-range Observations of B2 frequency after the non-poor Correction of Errors in external reference station, calculate the integer initial value of B2 frequency carrier phase ambiguity.According to formula (3), formula (20), ignore multipath effect, observation noise and non-model errors, calculate the integer initial value of B2 frequency carrier phase ambiguity formula be:

$N_{C2}^0=\mathrm{INT}(P_{C2}/{\mathrm{LMC}}_2+{\mathrm{COR}}_{\mathrm{CP}2}/{\mathrm{LMC}}_2-{\mathrm{COR}}_{C2}/{\mathrm{LMC}}_2-{\mathrm{\&Phi;}}_{C2})---\left(21\right)$

In formula, INT is round numbers symbol, gets its immediate integer by the value in bracket on the right side of equation.The precision that use formula (21) calculates B2 frequency carrier phase ambiguity integer initial value depends primarily on BDS system B2 frequency Pseudo-range Observations P _c2precision.

For current BDS system, at residual error item 0.01691N ' _c2when the absolute value of value is less than 0.25:

The BDS system B2 frequency carrier phase ambiguity initial value utilizing formula (21) to calculate integer reduction N ' _c2absolute value should be less than 15 weeks, the equivalent distances precision of B2 frequency Pseudo-range Observations is 3.7 meters, for residual error item 0.01691N ' _c2, then-0.25 < 0.01691N ' is had _c2< 0.25, do not affect difference blur level Parameter N between B2/L2 frequency carrier phase mixing star ' _c2-N ' _g2integer characteristic;

At residual error item 0.01691N ' _c2when the absolute value of value is less than 0.5:

The BDS system B2 frequency carrier phase ambiguity initial value then utilizing formula (21) to calculate precision should be less than 30 weeks, namely integer reduction N ' _c2the absolute value equivalent distances precision that is less than 30, B2 frequency Pseudo-range Observations be 7.4 meters, i.e. residual error item-0.5 < 0.01691N ' _c2< 0.5, does not affect blur level N ' _c2-N ' _g2integer characteristic.Generally, for current BDS system, the rough error of the BDS single-frequency Pseudo-range Observations in formula (21) can meet this accuracy requirement;

Utilize BDS system B2 frequency Pseudo-range Observations to calculate the integer initial value of B2 frequency carrier phase ambiguity, have two kinds of methods.Be the integer initial value that the B2 frequency Pseudo-range Observations of an epoch of use calculates B2 frequency carrier phase ambiguity, its precision mainly affects by the observation noise of B2 frequency Pseudo-range Observations.For BDS system, the precision of above-mentioned B2 frequency carrier phase ambiguity initial value can meet completely.This method utilizes the Pseudo-range Observations of an epoch to calculate the integer initial value of B2 frequency carrier phase ambiguity by formula (21); The second is the precision calculating the integer initial value of B2 frequency carrier phase ambiguity in order to improve B2 frequency Pseudo-range Observations, before using current epoch, the B2 frequency Pseudo-range Observations of multiple epoch calculates the integer initial value of B2 frequency carrier phase ambiguity, then the integer initial value of multiple identical B2 frequency carrier phase ambiguity is averaged, to improve the precision of B2 frequency carrier phase ambiguity integer initial value, namely utilize the B2 frequency Pseudo-range Observations of same satellite multiple epoch to be calculated the initial value of B2 frequency ambiguity degree by formula (21), then be averaged.

For BDS system, the precision of above-mentioned B2 frequency carrier phase ambiguity initial value can meet completely.For the above-mentioned situation with different residual error item, in the scope of B2 frequency carrier phase ambiguity initial value accuracy requirement, also eliminate residual error item, then formula (19) abbreviation is:

$\begin{array}{c}{\mathrm{LMC}}_2\&CenterDot;{\mathrm{\&Phi;}}_{C2}-{\mathrm{LMG}}_2\&CenterDot;{\mathrm{\&Phi;}}_{G2}+{\mathrm{COR}}_{C2}-{\mathrm{COR}}_{G2}\\ ={\mathrm{\&rho;}}_C-{\mathrm{\&rho;}}_G-({\mathrm{LMC}}_2\&CenterDot;N_{C2}^0-{\mathrm{LMG}}_2\&CenterDot;N_{G2}^0+{\mathrm{LMG}}_2\&CenterDot;(N_{C2}^{\&prime;}-N_{G2}^{\&prime;}))\end{array}---\left(22\right)$

In formula, N ' _c2-N ' _g2difference integer ambiguity parameter between the B2/L2 frequency carrier phase mixing star being observation equation (22), difference integer ambiguity N ' between B2/L2 frequency carrier phase mixing star now _c2-N ' _g2resolve identical with traditional baseline Ambiguity Solution Methods;

Step 4: difference integer ambiguity N ' between BDS system and gps system B2/L2 frequency carrier phase mixing star _c2-N ' _g2after determining, formula (14) or formula (22) is utilized to calculate survey station location parameter, then formula (3), formula (4) is utilized by survey station location parameter, calculate the initial integer solution of BDS system B2 frequency carrier phase ambiguity and gps system L2 frequency carrier phase ambiguity, the wherein receiver clock-offsets of formula (3), formula (4), is calculated by formula (12) or formula (20).Namely utilize the integer ambiguity determined to carry out the iterative computation of the initial integer solution of blur level, determine final integer ambiguity, between recycling B2/L2 frequency carrier phase mixing star, difference observed reading and blur level determine that user BDS/GPS receiver is to satellite distance.The calculating of mixing difference combined method and receiver location between the B2/L2 frequency carrier phase place star realizing BDS and GPS.

For the experimental data of Fig. 2, Fig. 3, after determining the L2 carrier phase ambiguity integer initial value of gps system, eliminate the error residue item 0.01664N ' of L2 ambiguity of carrier phase parameter _g2, and determine difference integer ambiguity parameter between B2/L2 carrier phase star.Formula (14) is utilized to calculate the distance ρ of BDS/GPS receiver to satellite _c-ρ _g, and then carry out the calculating of receiver location.Obtain receiver after the position coordinates of three coordinate components X, Y, Z, compared by the known accurate coordinate of its result and receiver location, as shown in Figure 4, transverse axis represents that observation time is second in week to its difference, and the longitudinal axis represents the size of difference, and unit is rice.The RMS of X, Y, Z tri-coordinate components differences is respectively 0.021 meter, 0.024 meter, 0.022 meter.Demonstrate difference between mixing star that present embodiment can realize BDS system and gps system B2/L2 carrier phase observation data to combine, keep the integer characteristic of difference blur level parameter between dual system star, realize the hi-Fix of dual system reception machine.

Although the foregoing describe the specific embodiment of the present invention, the those skilled in the art in this area should be appreciated that these only illustrate, can make various changes or modifications, and do not deviate from principle of the present invention and essence to these embodiments.Scope of the present invention is only defined by the appended claims.

Claims (5)

1. a mixing difference method between the B2/L2 carrier phase star of BDS and GPS, is characterized in that: the non-Correction of Errors number under the B2 frequency first utilizing external reference station to provide, L2 frequency two kinds of frequencies eliminates satellite orbital error, tropospheric delay error and ionosphere delay error in carrier phase observation data;

Poor to the B2/L2 carrier phase observation data of BDS system and gps system again, eliminate same receiver to the receiver error in different satellite B2, L2 carrier phase observation data, and the integer characteristic of difference blur level between the star recovering B2/L2 frequency carrier carrier phase observable, and then determine BDS system and gps system B2/L2 carrier phase observation data;

Finally utilize this observed reading, determine the distance between BDS system and gps system satellite to receiver;

Described elimination same receiver is to the receiver error in different satellite carrier carrier phase observable, method makes the carrier phase ambiguity parameter of the carrier phase ambiguity parameter of BDS system B2 frequency and gps system L2 frequency merge into a blur level parameter, use following 2 kinds of methods any one:

(1) the integer reduction of the L2 frequency carrier phase ambiguity of a satellite in BDS system in the integer reduction of the B2 frequency carrier phase ambiguity of a satellite, gps system forms a blur level parameter by difference between star, again with the B2 frequency carrier phase ambiguity wavelength of BDS system for coefficient, change into difference blur level between star, formula is:

${\mathrm{LMC}}_2\&CenterDot;N_{C2}-{\mathrm{LMG}}_2\&CenterDot;N_{G2}={\mathrm{LMC}}_2\&CenterDot;N_{C2}^0-{\mathrm{LMG}}_2\&CenterDot;N_{G2}^0+({\mathrm{LMC}}_2\&CenterDot;N_{C2}^{\&prime;}-{\mathrm{LMG}}_2\&CenterDot;N_{G2}^{\&prime;})---\left(1\right)$

In formula, LMC ₂it is the wavelength of BDS system B2 frequency carrier phase place; N _c2it is the integer ambiguity of the B2 frequency carrier carrier phase observable of BDS system; LMG ₂for the wavelength of gps system L2 frequency carrier phase place, N _g2it is the integer ambiguity of the L2 frequency carrier carrier phase observable of gps system; for the initial integer solution of BDS system B2 frequency carrier phase ambiguity, for the initial integer solution of the L2 frequency carrier phase ambiguity of gps system; N' _c2for the integer reduction of BDS system B2 frequency carrier Phase integer ambiguity, N' _g2for the integer reduction of gps system L2 frequency carrier phase ambiguity, the size of the integer reduction of B2/L2 frequency carrier phase ambiguity is relevant with the integer initial value of blur level;

(2) the integer reduction of the integer reduction of the B2 frequency carrier phase ambiguity of a BDS system satellite and the L2 frequency carrier phase ambiguity of a gps system satellite, by being combined into a blur level after difference between star, and with the L2 frequency carrier phase ambiguity wavelength of gps system for coefficient, form difference blur level between star, formula is as follows:

${\mathrm{LMC}}_2\&CenterDot;N_{C2}-{\mathrm{LMG}}_2\&CenterDot;N_{G2}={\mathrm{LMC}}_2\&CenterDot;N_{C2}^0-{\mathrm{LMG}}_2\&CenterDot;N_{G2}^0+{\mathrm{LMC}}_2\&CenterDot;(N_{C2}^{\&prime;}-\frac{{\mathrm{LMG}}_2}{{\mathrm{LMC}}_2}\&CenterDot;N_{G2}^{\&prime;})---\left(2\right)$

In formula, for the blur level parameter that difference between BDS system B2 frequency carrier phase place and gps system L2 frequency carrier phase place star combines.

2. mixing difference method between the B2/L2 carrier phase star of BDS and GPS according to claim 1, is characterized in that: for difference blur level between star determined in (1) the method recovering its integer characteristic is:

BDS system is different with B2, L2 carrier phase wavelength of gps system, and ask for wavelength ratio, formula is:

$\frac{{\mathrm{LMG}}_2}{{\mathrm{LMC}}_2}=A---\left(3\right)$

In formula, A represents L2, B2 carrier phase wavelength ratio of gps system and BDS system, and has A ∈ (0,1);

Single poor blur level parameter between the star then in formula (7) replace with further:

$N_{C2}^{\&prime;}-\frac{{\mathrm{LMG}}_2}{{\mathrm{LMC}}_2}\&CenterDot;N_{G2}^{\&prime;}=N_{C2}^{\&prime;}-A\&CenterDot;N_{G2}^{\&prime;}=N_{C2}^{\&prime;}-N_{G2}^{\&prime;}+(1-A)\&CenterDot;N_{G2}^{\&prime;}---\left(4\right)$

In formula, N' _c2and N' _g2be all unknown complete cycle number, i.e. N' _c2-N' _g2for differentiated blur level parameter between BDS system B2 frequency carrier phase place and gps system L2 frequency carrier phase place star, (1-A) N' _g2be single poor blur level Parameter N between star ' _c2-N' _g2residual error item, then have:

$\begin{array}{c}{\mathrm{LMC}}_2\&CenterDot;{\mathrm{\&Phi;}}_{C2}-{\mathrm{LMC}}_2\&CenterDot;{\mathrm{\&Phi;}}_{G2}+{\mathrm{COR}}_{C2}-{\mathrm{COR}}_{G2}\\ ={\mathrm{\&rho;}}_C-{\mathrm{\&rho;}}_G-\left({\mathrm{LMC}}_2\&CenterDot;N_{C2}^0-{\mathrm{LMG}}_2\&CenterDot;N_{G2}^0+{\mathrm{LMC}}_2\&CenterDot;\left(N_{C2}^{\&prime;}-\frac{{\mathrm{LMG}}_2}{{\mathrm{LMC}}_2}\&CenterDot;N_{G2}^{\&prime;}\right)\right)\\ ={\mathrm{\&rho;}}_C-{\mathrm{\&rho;}}_G-\left({\mathrm{LMC}}_2\&CenterDot;N_{C2}^0-{\mathrm{LMG}}_2\&CenterDot;N_{G2}^0+{\mathrm{LMC}}_2\&CenterDot;\left(N_{C2}^{\&prime;}-N_{G2}^{\&prime;}-\left(A-1\right)\&CenterDot;N_{G2}^{\&prime;}\right)\right)\end{array}---\left(5\right)$

In formula, Φ _c2be BDS system B2 carrier phase observation data, subscript C represents BDS system; Φ _g2be gps system L2 frequency carrier carrier phase observable, subscript G represents gps system; COR _c2for the non-mistake difference correction of the BDS system B2 frequency carrier phase place that external reference station provides; COR _g2for the non-mistake difference correction of gps system L2 frequency carrier phase place; ρ _cfor BDS satellite is to the geometric distance of receiver; ρ _gfor gps satellite is to the geometric distance of receiver;

Determine the integer initial value of gps system L2 frequency carrier phase ambiguity, residual error item is eliminated, recover blur level integer characteristic.

3. mixing difference method between the B2/L2 carrier phase star of BDS and GPS according to claim 1, is characterized in that: for difference blur level between the determined star described in (2) the method recovering its integer characteristic is:

BDS system is different with B2, L2 carrier phase wavelength of gps system, and ask for wavelength ratio, formula is:

$\frac{{\mathrm{LMC}}_2}{{\mathrm{LMG}}_2}=B---\left(6\right)$

In formula, B represents the B2 frequency carrier phase wave length of BDS system and the L2 frequency carrier phase wave length ratio of gps system, and has B ∈ (1,2);

Single poor blur level between star write as further:

$\frac{{\mathrm{LMC}}_2}{{\mathrm{LMG}}_2}\&CenterDot;N_{C2}^{\&prime;}-N_{G2}^{\&prime;}={\mathrm{BN}}_{C2}^{\&prime;}-N_{G2}^{\&prime;}=N_{C2}^{\&prime;}-N_{G2}^{\&prime;}-(1-B)\&CenterDot;N_{C2}^{\&prime;}---\left(7\right)$

In formula, (B-1) N' _c1for complete cycle number N' _c1-N' _g1residual error item, then have:

$\begin{array}{c}{\mathrm{LMC}}_2\&CenterDot;{\mathrm{\&Phi;}}_{C2}-{\mathrm{LMC}}_2\&CenterDot;{\mathrm{\&Phi;}}_{G2}+{\mathrm{COR}}_{C2}-{\mathrm{COR}}_{G2}\\ ={\mathrm{\&rho;}}_C-{\mathrm{\&rho;}}_G-\left({\mathrm{LMC}}_2\&CenterDot;N_{C2}^0-{\mathrm{LMG}}_2\&CenterDot;N_{G2}^0+{\mathrm{LMG}}_2\&CenterDot;\left(\frac{{\mathrm{LMV}}_2}{{\mathrm{LMG}}_2}\&CenterDot;N_{C2}^{\&prime;}-N_{G2}^{\&prime;}\right)\right)\\ ={\mathrm{\&rho;}}_C-{\mathrm{\&rho;}}_G-\left({\mathrm{LMC}}_2\&CenterDot;N_{C2}^0-{\mathrm{LMG}}_2\&CenterDot;N_{G2}^0+{\mathrm{LMG}}_2\&CenterDot;\left(N_{C2}^{\&prime;}-N_{G2}^{\&prime;}+\left(B-1\right)\&CenterDot;N_{C2}^{\&prime;}\right)\right)\end{array}---\left(8\right)$

Determine the integer initial value of BDS system B2 frequency carrier phase ambiguity, residual error item is eliminated, recover blur level integer characteristic.

4. mixing difference method between the B2/L2 carrier phase star of BDS and GPS according to claim 2, it is characterized in that: the integer initial value of described determination gps system L2 frequency carrier phase ambiguity, method is:

For gps system, when the absolute value of residual error item value is less than 0.5:

If utilize the Pseudo-range Observations of gps system L2 frequency to calculate L2 frequency carrier phase ambiguity integer initial value, then the deviation of gps system L2 carrier phase ambiguity initial value should be less than 30 weeks;

When the absolute value of residual error item value is less than 0.25:

If the Pseudo-range Observations of the Pseudo-range Observations of gps system L2 frequency calculates L2 frequency carrier phase ambiguity integer initial value, then the deviation of gps system L2 frequency carrier phase ambiguity initial value should be less than 15 weeks.

5., according to mixing difference method between the B2/L2 carrier phase star of BDS and GPS according to claim 3, it is characterized in that: the integer initial value of described determination BDS system B2 frequency carrier phase ambiguity, method is:

Utilize BDS system B2 frequency Pseudo-range Observations to calculate the initial value of BDS system B2 frequency carrier phase ambiguity, the minimum requirements that initial value should meet is:

For current BDS system, when the absolute value of residual error item value is less than 0.5:

If utilize the Pseudo-range Observations of BDS system B2 frequency to calculate B2 carrier phase ambiguity integer initial value, then the deviation of BDS system B2 frequency carrier phase ambiguity initial value should be less than 30 weeks;

When the absolute value of residual error item value is less than 0.25:

If utilize the Pseudo-range Observations of BDS system B2 frequency to calculate B2 carrier phase ambiguity integer initial value, then the deviation of BDS system B2 frequency carrier phase ambiguity initial value should be less than 15 weeks.