CN101770033A - Fixing method of ambiguity network between CORS and system station - Google Patents

Abstract

The invention discloses a fixing method of an ambiguity network between CORS system stations, which comprises the following steps: first, a wide-lane ambiguity float solution is worked out with the linear combination of carrier wave and pseudorange, the mean is solved through multi-epoch according to the long-wave features of wide-lane ambiguity, to determine the wide-lane ambiguity integer solution; and then the delay dry weight of a troposphere is estimated through a Neill model, L1 ambiguity is separated by the independent combination of an ionosphere, so as to determine L2 ambiguity; and finally accuracy test of ambiguity resolution is carried out. The method provided by the invention can fix the baseline ambiguity between CORSs in a short time, is quick, stable and easy to be implemented in projects.

Description

Integer ambiguity network fixing means between the CORS system station

Technical field

The present invention relates in the GNSS network differential positioning system baseline integer ambiguity network calculation method between reference station, relate in particular to integer ambiguity network fixing means between CORS (CORS) system station, belong to GNSS network differential positioning field.

Background technology

GNSS network differential location technology is the hot technology in present satnav field, be widely used in industries such as mapping and survey of territorial resources, with virtual reference station technology (VRS) is the network differential technology rise of representative, makes and sets up the recent tendency that reference station network type GPS service system becomes Current GPS technology application development.The VRS technology is as the GPS real-time dynamic positioning technology under many reference stations environment, be that collection Internet technology, wireless communication technique, computer networking technology and GPS technology are the network RTK location technology of one, also be wide, the most successful representative high-tech achievement of current application, the VRS technical system has been represented the conventional RTK developing direction of location technology of new generation afterwards.

The online of baseline integer ambiguity fixedly is the prerequisite that realizes the VRS technology between reference station.Growth along with parallax range between reference station, the systematic error correlativity weakens even disappears, systematic error residual error in two poor observed readings increases rapidly, cause being difficult to correctly determining integer ambiguity, make bearing accuracy descend, thereby the online of long baseline integer ambiguity fixedly is the important technological problems of restriction VRS/RTK real-time, reliability between reference station.The long baseline Ambiguity Solution Methods of domestic and international many scholar's centerings has been carried out many research work, mainly contain following certain methods: 1, Gao Xingwei has proposed single epoch of the integer ambiguity search procedure (Gao Xingwei between reference station, 2002), the main thought of this method is not understand system of equations, utilize directly that the survey station coordinate is known, blur level is searched for for these three conditions of the linear relationship between integer and the double frequency integer ambiguity, but its principle and imperfection, reliable be not so this method is used widely; 2, the Fast Carrier Phase Ambiguity Resolution of Zhou Letao is another kind of effectively long baseline blur level fixing means (Zhou Letao, 2006), and it resolves thinking and is to use parallel filtering and expands wave technology (Sun, 1999; Chen, 2000): earlier to the parallel Kalman filtering of carrying out of the irrelevant blur level of wide lane ambiguity and ionosphere, because the long wave characteristic in wide lane, must be found the solution earlier in the filtering, again with it as given value substitution ionosphere independent combination, make ionosphere independent combination wavelength expand 0.107m to by 0.006m, estimate to fix blur level and calculating parameter static solution by the estimation of component that zenith tropospheric delay is wet with to the integer of L1 blur level at last, but this method requires high for model parameter in the Kalman filtering.

Summary of the invention

The present invention is directed to the deficiency of prior art, proposed a kind of fast and be easy to that baseline integer ambiguity network calculation method is an integer ambiguity network fixing means between the CORS system station between the reference station of Project Realization, the technical scheme of this method is:

Integer ambiguity network fixing means between the CORS system station, it is characterized in that: at first utilize the linear combination of carrier wave and pseudorange to find the solution wide lane ambiguity floating-point and separate, long wave characteristic according to wide lane ambiguity, determine wide lane ambiguity integer solution, promptly wide lane integer ambiguity by finding the solution mean value many epoch; Estimate the dried wet component of tropospheric delay by the Neill model then, adopt the ionosphere independent combination to isolate the two difference of L1 carrier wave blur level, the two difference of definite then L2 carrier wave blur leveles; Carry out the verifying correctness of Carrier Phase Ambiguity Resolution at last.

Specifically can be according to the following steps:

(1) each reference station continuous acquisition observation data, and be real-time transmitted to central server, correspondence is added in the base station at each bar baseline two ends, has promptly imported L1, L2 carrier phase observation data, P1, information such as P2 pseudo range observed quantity.

(2) wide lane integer ambiguity fixes fast.Utilize the double frequency phase observed reading can eliminate ionospheric influence effectively, and by differential technique can cancellation receiver clock correction, the influence of satellite clock correction, weaken the influence (shorter baseline even can ignore) of track deviation and atmosphere delay deviation simultaneously to a great extent.Two kinds of methods of fixing main employing of wide lane integer ambiguity: a kind of is wide lane combination definition solving method, promptly directly finds the solution according to the definition of wide lane combination observation value, resolves the influence that the result mainly is subjected to atmosphere errors, is applicable to base length 30～50km; Another kind is dual-frequency P sign indicating number and phase observations value LINEAR COMBINATION METHOD, resolves the influence that the result mainly is subjected to the pseudorange precision, is applicable to that base length is 50～100km.Base length was selected calculation method during the present invention can use according to engineering, with fast fixing wide lane integer ambiguity.

1) wide lane combination definition solving method

According to the definition of the wide lane of double frequency combination observation value, can be expressed as wide lane ambiguity:

In the formula,

Be two poor operators; N _wBe wide lane ambiguity;

With

Be respectively L ₁, L ₂The wave band carrier phase observation data; f ₁, f ₂Be L ₁, L ₂The frequency of wave band; λ _w=c/ (f ₁-f ₂) be the wavelength of wide lane observed reading; ρ, O, T, I, M, ε are respectively and defend distance, orbit error, tropospheric delay, ionosphere delay, multipath effect and observation noise.

In CORS (CORS) network, satellite orbital error and Multi-Path Effects can be ignored, and defending distance can accurate Calculation obtain, so in following formula, Influenced by ionosphere and tropospheric two difference residual error.Because two differences tropospheres mainly are subjected to the influence of base length and satellite altitude angle size, promptly increase along with the increase of base length, reduce with the increase at satellite altitude angle, particularly the two difference of low clearance cornerdown star tropospheric delay sharply increase.Therefore, when base length within the specific limits, by setting satellite, consider wide lane wavelength X again by 10～20 ° of elevation angles _w=86.2cm, ionosphere and tropospheric two difference residual error can be controlled within the half cycle the influence of wide lane ambiguity, utilize this method can determine single epoch

Value.

2) dual-frequency P sign indicating number and phase observations value LINEAR COMBINATION METHOD

Because the GPS receiver that dual-frequency code is relevant not only can obtain carrier phase observation data, and can also obtain L1, the P sign indicating number pseudorange on the L2 frequency, so can adopt the LINEAR COMBINATION METHOD of dual-frequency P sign indicating number and phase observations value to find the solution wide lane ambiguity:

P in the formula ₁, P ₂Be respectively L ₁, L ₂Wave band P sign indicating number pseudorange value.As can be seen, following formula has been eliminated the ionospheric convection layer and has been defended the distance influence for how much, ignores multipath effect, and following formula only is subjected to the influence of remaining two difference observation noises.Though the influence of pseudorange noise ratio carrier phase is much bigger, because the long wave characteristic of wide lane combination, the pseudorange noise is effectively suppressed.

Because the pseudorange The noise only utilizes list observed reading epoch to be difficult to correctly fixedly go out wide lane ambiguity according to following formula

In the reference station network, sampling interval is very short, and in order to fix wide lane ambiguity exactly, the present invention is according to the accidental error characteristic of noise, and comprehensive many epoch, observation data was found the solution.

(3) the two difference of L1, L2 ambiguity resolution.After the wide lane ambiguity of two differences is determined, utilize and the irrelevant linear combination in ionosphere, adopt the Neill model to estimate the dried wet component of tropospheric delay simultaneously,, determine the two difference of L2 integer ambiguity then by 1 pair of poor integer ambiguity of the quick fixed L of sequential least square condition adjustment.And make full use of the topological relation of GNSS network differential positioning system base station net, check the accuracy of the two difference of L1, L2 blur level integer solutions, thereby improve the success ratio of two difference ambiguity resolution.

Adopt ionosphere independent linearity combination to determine

Promptly

$=\frac{1}{{\mathrm{\&lambda;}}_w}(\mathrm{\&Delta;}\&dtri;\mathrm{\&rho;}+\mathrm{\&Delta;}\&dtri;O+\mathrm{\&Delta;}\&dtri;T)+\frac{f_2}{{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HSA00000022077200031.png"\; state="\{\{state\}\}">f</figure-callout>}}_1+f_2}{\mathrm{\&Delta;}\&dtri;N}_1-\frac{f_2}{{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HSA00000022077200031.png"\; state="\{\{state\}\}">f</figure-callout>}}_1+f_2}\mathrm{\&Delta;}\&dtri;N_2$

In the formula,

Be two poor operators;

Be no ionosphere delay combination observation value, ρ is station star distance, and O is an orbit error, and T is a tropospheric delay, takes narrow lane observed reading wavelength X into account _n=c/ (f ₁+ f ₂) and according to wide lane ambiguity definition ${\mathrm{\&Delta;}\&dtri;N}_2={\mathrm{\&Delta;}\&dtri;N}_1-{\mathrm{\&Delta;}\&dtri;N}_w,$ Have

Because in the reference station network, satellite orbital error and Multi-Path Effects can be ignored, defending distance can accurate Calculation obtain,

After accurately obtaining, determine in the following formula

The main source that influences from tropospheric two difference residual errors.Because of tropospheric influence and satellite altitude angular dependence (-dance), introduce mapping function for this reason, it is expressed as zenith delay and about the product of the mapping function at satellite altitude angle, so can be with two difference blur leveles of L1 carrier wave

As parameter to be estimated, zenith tropospheric delay ZD can obtain its initial value by the Neill model, is calculated as follows

$\left[\begin{array}{ccccc}\&dtri;\mathrm{MF}\left({\mathrm{\&theta;}}_p^1\right)& -\&dtri;\mathrm{MF}\left({\mathrm{\&theta;}}_q^1\right)& {\mathrm{\&lambda;}}_n& ...& 0\\ \&dtri;\mathrm{MF}\left({\mathrm{\&theta;}}_p^2\right)& -\&dtri;\mathrm{MF}\left({\mathrm{\&theta;}}_q^2\right)& 0& {\mathrm{\&lambda;}}_n& ...\\ .& .& .& .& .\\ .& .& .& .& .\\ .& .& .& .& .\\ \&dtri;\mathrm{MF}\left({\mathrm{\&theta;}}_p^k\right)& -\&dtri;\left({\mathrm{\&theta;}}_q^k\right)& 0& ...& {\mathrm{\&lambda;}}_n\end{array}\right]\&times;\left[\begin{array}{c}{\mathrm{ZD}}_p\\ {\mathrm{ZD}}_q\\ {{\mathrm{\&Delta;}\&dtri;\mathrm{<figure-callout\; id="1"\; label="N"\; filenames="HSA00000022077200031.png"\; state="\{\{state\}\}">N</figure-callout>}}_1}^1\\ {{\mathrm{\&Delta;}\&dtri;\mathrm{<figure-callout\; id="1"\; label="N"\; filenames="HSA00000022077200031.png"\; state="\{\{state\}\}">N</figure-callout>}}_1}^2\\ .\\ .\\ .\\ {{\mathrm{\&Delta;}\&dtri;N}_1}^k\end{array}\right]$

In the formula, MF () is the troposphere mapping function; λ _n, λ _wIt is respectively the wavelength of narrow lane and wide lane observation;

Be the combination of no ionosphere; Be wide lane ambiguity; f ₁, f ₂Frequency for L1 and L2;

Be that two differences are defended distance; P, q are the reference station numbering; K+1 is the observation satellite number.

For resolving of following formula, the present invention adopts sequential adjustment to carry out the two difference of L1 carrier wave blur level

Resolve the sequential adjustment calculation method.

Be located at t _kHave m+1 satellite epoch, and n is arranged _k* 1 observation vector L _k, corresponding covariance matrix is Q _k, weight matrix is

At t _K-1Obtain the model parameter vector estimated value epoch

Corresponding covariance matrix is Q _K-1, error equation is:

$V_k=A_k{\hat{X}}_k-L_k$

In the formula:

Be n _k* (m+2) design matrix;

Be n _k* 1 observing matrix;

${\hat{X}}_k={\left[\begin{array}{cccc}{\mathrm{ZD}}_p& {\mathrm{ZD}}_q& {\mathrm{\&Delta;}\&dtri;\mathrm{<figure-callout\; id="1"\; label="N"\; filenames="HSA00000022077200031.png"\; state="\{\{state\}\}">N</figure-callout>}}_1& ...\end{array}\right]}^T$ Be (m+2) * 1 state estimation vector;

It is as follows to resolve process:

$\left\{\begin{array}{c}{P}_{{\hat{X}}_k}=A_k^T{P}_k{A}_k+P_{\widehat{X_{k-1}}}\\ P_{L_k}=A_k^T{P}_k{L}_k+P_{L_{k-1}}\\ {\hat{X}}_k=P_{{\hat{X}}_k}^{-1}{P}_{L_k}=P_{{\hat{X}}_k}^{-1}(A_k^T{P}_k{L}_k+P_{\widehat{X_{k-1}}}\widehat{X_{k-1}})\end{array}\right.$

Initial value is $P_{{\hat{X}}_1}=A_1^T{P}_1{A}_1,$ ${\mathrm{<figure-callout\; id="1"\; label="P\; L"\; filenames="HSA00000022077200031.png"\; state="\{\{state\}\}">P</figure-callout>}}_{L_{}}=A_1^T{P}_1{\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="HSA00000022077200031.png"\; state="\{\{state\}\}">L</figure-callout>}}_1;$

By above-mentioned sequential adjustment method, can determine the two difference of L1 blur level

The two difference of L2 blur level: ${\mathrm{\&Delta;}\&dtri;N}_2={\mathrm{\&Delta;}\&dtri;N}_1-{\mathrm{\&Delta;}\&dtri;N}_w;$

(4) network checks of blur level correctness.In view of the characteristics of reference station network, can pass through many baselines of reference station network combinatorial test blur level correctness.Inner network forming algorithm had substantial connection when this kind method of inspection calcaneus rete network differential system software was realized, the present invention adopts the Delaunay triangulation network as the base station network.

When adopting the Delaunay triangulation network, with triangle for resolving the unit substantially, article three, baseline is chosen identical reference satellite and is carried out two subtractive combinations, then for three baselines that resolve the unit in the network arbitrarily, all there is following relation (the unit Cel_ABC that resolves that constitutes with ABC is an example) in their corresponding blur level:

${\mathrm{\&Delta;}\&dtri;N}_{\mathrm{AB}}^{\mathrm{ij}}+{\mathrm{\&Delta;}\&dtri;N}_{\mathrm{BC}}^{\mathrm{ij}}+{\mathrm{\&Delta;}\&dtri;N}_{\mathrm{CA}}^{\mathrm{ij}}=0$

Advantage of the present invention and beneficial effect:

(1) the present invention can be used for the realization of the Network RTK of CORS system technology, the integer ambiguity between promptly can the real-time resolving reference station, thus prepare for generating dummy observation or correction.

(2) the present invention also is that baseline resolves the core algorithm of software afterwards.

Description of drawings

Fig. 1 is a baseline integer ambiguity network calculation method process flow diagram between reference station among the present invention;

Fig. 2 is a base station network diagram among the present invention;

Fig. 3 is an experiment base station network diagram among the present invention;

Fig. 4 is that wide lane combination definition solving method is found the solution wide lane ambiguity and separated figure as a result single epoch among the present invention;

Fig. 5 be among the present invention dual-frequency P sign indicating number and phase observations value LINEAR COMBINATION METHOD find the solution wide lane ambiguity single epoch of value and many epoch the mean value synoptic diagram;

Fig. 6 adopts the ionosphere independent combination to find the solution the two difference of L1 blur level synoptic diagram among the present invention.

Embodiment

Referring to Fig. 1, among the present invention between reference station baseline integer ambiguity network calculation method mainly undertaken by following flow process:

(1) each reference station continuous acquisition observation data, and be real-time transmitted to central server, correspondence is added in the base station at each bar baseline two ends, has promptly imported to comprise L1 L2 carrier phase observation data, P1, P2 pseudo range observed quantity information;

(2) select following two kinds of methods to resolve according to on-site actual situations and determine wide lane integer ambiguity:

When 1) base length is 30～50km, adopt wide lane combination definition solving method:

When 2) base length is 50～100km, adopt double frequency pseudorange P sign indicating number P1, P2 and phase observations value linear combination solving method:

(3) the two difference of L1, L2 ambiguity resolution

After the wide lane ambiguity of two differences is determined, utilize and the irrelevant linear combination in ionosphere, adopt the Neill model to estimate the dried wet component of tropospheric delay simultaneously,, determine the two difference of L2 integer ambiguity then by 1 pair of poor blur level of the quick fixed L of sequential least square condition adjustment;

(4) network checks of the two difference of L1, L2 blur level correctness:

When adopting the Delaunay triangulation network, with triangle for resolving the unit substantially, article three, baseline is chosen identical reference satellite and is carried out two subtractive combinations, then for three baselines that resolve the unit in the network arbitrarily, all there is following relation in their corresponding blur level, concern below satisfying that the two difference of L1, L2 blur leveles are correct

${\mathrm{\&Delta;}\&dtri;N}_{\mathrm{AB}}^{\mathrm{ij}}+{\mathrm{\&Delta;}\&dtri;N}_{\mathrm{BC}}^{\mathrm{ij}}+{\mathrm{\&Delta;}\&dtri;N}_{\mathrm{CA}}^{\mathrm{ij}}=0$

If the two difference of L1, L2 blur level satisfies following formula, then the search of the two difference of L1, L2 blur level finishes, and resolves end; Otherwise,, promptly, resolve again from resolving wide lane two difference blur level from (1).

Referring to Fig. 2, be the base station network, wherein alphabetical A-F represents base station, presses the network forming of Delaunay triangulation network network forming principle, sets up the CORS network, determines the triangle at place according to customer location, thereby carries out the network checks of the two difference of L1, L2 blur level correctness.

Use Jiangsu CORS data as example below.Experimental data is the observation data of three stations 30min on the 6th in (station, Jurong (BTJR), station, Yangzhou (BFYZ), Yang Zhongzhan (BTZF)) March in 2007 in the CORS of Jiangsu, Fig. 3 is three station topological relation figure, baseline BTJR-BFYZ (length 53353.895m) wherein, baseline BFYZ-BTZF (length 43668.153m), baseline BTZF-BTJR (length 70022.556m).The method that employing the present invention proposes is resolved its pair difference blur level, and end product is compared with the result that resolves who adopts high precision Bernese to resolve software.

The first step: fixing fast of wide lane ambiguity, adopt wide lane combination definition solving method and dual-frequency P sign indicating number and two kinds of methods of phase observations value LINEAR COMBINATION METHOD to find the solution wide lane ambiguity respectively, the PRN2 satellite that has just risen with baseline is example result such as Fig. 4, shown in Figure 5.

From Fig. 4, Fig. 5 as can be seen, wide lane combination definition solving method is separated error when very little single epoch at the satellite altitude angle bigger, along with the change at satellite altitude angle is big, resolves the result gradually near the correct round values of wide lane ambiguity.And in dual-frequency P sign indicating number and the phase observations value LINEAR COMBINATION METHOD single epoch of combination observation value all epoch separate and all on correct round values, fluctuate in next all left and right sides scope, variation with the satellite altitude angle is irrelevant, promptly adopt separate single epoch and can't fix wide lane ambiguity value, but after the method for totally averaging many epoch, wide lane ambiguity levels off to round values fast along with increasing of epoch, and wide lane ambiguity is fixed.

The present invention finds to adopt wide lane combination definition solving method in that base length is suitable during less than 50km through mass data test; In base length greater than 50km appropriate to the occasion employing dual-frequency P sign indicating number and phase observations value LINEAR COMBINATION METHOD.

Determining of second step: the L1 two difference blur level.The two difference of L1 carrier wave blur level restrains situation for convenience of explanation, and the blur level convergence situation of choosing No. 11 satellites of PRN shows that No. 28 satellites of PRN are as the reference satellite; Resolve the result according to Bernese, G28-G11CA 00:00:00...01:45:00 float=14.879 fixed=15.000 sigma=0.121num=421, then the two difference of the L1 carrier wave of PRN 11 blur level is 15.Resolve the result as shown in Figure 6.

As can be seen from Figure 6, when value that inferior little variance and minimum variance ratio＞F distributes, the two difference of No. 11 satellites of PRN blur leveles are fixed, and the set time, it is consistent that result and Bernese resolve the result, satisfies CORS system related request fully about 180s.

The 3rd step: the network checks of blur level correctness.The present invention carries out the ambiguity resolution of aforesaid way to three baselines shown in Fig. 3, is example with No. 11 satellites of PRN, and the two difference of L1 blur leveles are as follows:

Baseline BTJR-BFYZ:15

Baseline BFYZ-BTZF:8

Baseline BTZF-BTJR:-23

Satisfy ${\mathrm{\&Delta;}\&dtri;N}_{\mathrm{AB}}^{\mathrm{ij}}+{\mathrm{\&Delta;}\&dtri;N}_{\mathrm{BC}}^{\mathrm{ij}}+{\mathrm{\&Delta;}\&dtri;N}_{\mathrm{CA}}^{\mathrm{ij}}=0$ This test condition.

Claims (2)

1. integer ambiguity network fixing means between the CORS system station, it is characterized in that: at first utilize the linear combination of carrier wave and pseudorange to find the solution wide lane ambiguity floating-point and separate, long wave characteristic according to wide lane ambiguity, determine wide lane ambiguity integer solution, promptly wide lane integer ambiguity by finding the solution mean value many epoch; Estimate the dried wet component of tropospheric delay by the Neill model then, adopt the ionosphere independent combination to isolate the two difference of L1 carrier wave blur level, the two difference of definite then L2 carrier wave blur leveles; Carry out the verifying correctness of Carrier Phase Ambiguity Resolution at last.

2. according to integer ambiguity network fixing means between the described CORS system station of claim 1, specifically according to the following steps:

(1) each reference station continuous acquisition observation data, and be real-time transmitted to central server, correspondence is added in the base station at each bar baseline two ends, has promptly imported to comprise L1 L2 carrier phase observation data, P1, P2 pseudo range observed quantity information;

(2) select following two kinds of methods to resolve according to on-site actual situations and determine wide lane integer ambiguity:

When 1) base length is 30～50km, adopt wide lane combination definition solving method:

Definition according to the wide lane of double frequency combination observation value is expressed as wide lane ambiguity:

In the formula,

Be two poor operators; N _wBe wide lane ambiguity;

With

Be respectively L ₁, L ₂The wave band carrier phase observation data; f ₁, f ₂Be L ₁, L ₂The frequency of wave band; λ _w=c/ (f ₁-f ₂) be the wavelength of wide lane observed reading; ρ, O, T, I, M, ε are respectively and defend distance, orbit error, tropospheric delay, ionosphere delay, multipath effect and observation noise;

In CORS CORS network, satellite orbital error and Multi-Path Effects are ignored, and defending distance can accurate Calculation obtain, so in following formula,

Influenced by ionosphere and tropospheric two difference residual error, because two differences troposphere mainly is subjected to the influence of base length and satellite altitude angle size, promptly increase along with the increase of base length, increase with the satellite altitude angle reduces, particularly the two difference of low clearance cornerdown star tropospheric delay sharply increase, therefore, when base length within the specific limits, by setting satellite, consider wide lane wavelength X again by 10～20 ° of elevation angles _w=86.2cm, ionosphere and tropospheric two difference residual error can be controlled within the half cycle the influence of wide lane ambiguity, utilize this method can determine single epoch

Value, the wide lane ambiguities of promptly two differences;

When 2) base length is 50～100km, adopt double frequency pseudorange P sign indicating number P1, P2 and phase observations value linear combination solving method:

Because the GPS receiver that dual-frequency code is relevant not only can obtain carrier phase observation data, and can also obtain L1, the P sign indicating number pseudorange on the L2 frequency, adopt the LINEAR COMBINATION METHOD of dual-frequency P sign indicating number and phase observations value to find the solution wide lane ambiguity:

P in the formula ₁, P ₂Be respectively L ₁, L ₂Wave band P sign indicating number pseudorange value; According to the accidental error characteristic of noise, adopt comprehensive many epoch observation datas to find the solution;

(3) the two difference of L1, L2 ambiguity resolution

After the wide lane ambiguity of two differences is determined, utilize and the irrelevant linear combination in ionosphere, adopt the Neill model to estimate the dried wet component of tropospheric delay simultaneously,, determine the two difference of L2 integer ambiguity then by 1 pair of poor blur level of the quick fixed L of sequential least square condition adjustment;

Adopt ionosphere independent linearity combination to determine , promptly find the solution the two difference of L1 blur level:

$=\frac{1}{{\mathrm{\&lambda;}}_w}(\mathrm{\&Delta;}\&dtri;\mathrm{\&rho;}+\mathrm{\&Delta;}\&dtri;O+\mathrm{\&Delta;}\&dtri;T)+\frac{f_2}{f_1+f_2}{\mathrm{\&Delta;}\&dtri;N}_1-\frac{f_2}{f_1+f_2}{\mathrm{\&Delta;}\&dtri;N}_2$

In the formula, Be two poor operators; Be no ionosphere delay combination observation value, ρ is station star distance, and O is an orbit error, and T is a tropospheric delay, takes narrow lane observed reading wavelength X into account _n=c/ (f ₁+ f ₂) and according to wide lane ambiguity definition

Have

Introduce mapping function, it is expressed as zenith delay and about the product of the mapping function at satellite altitude angle, with two difference blur leveles of L1

As parameter to be estimated, zenith tropospheric delay ZD can obtain its initial value by the Neill model, is calculated as follows:

$\left[\begin{array}{ccccc}\&dtri;\mathrm{MF}\left({\mathrm{\&theta;}}_p^1\right)& -\&dtri;\mathrm{MF}\left({\mathrm{\&theta;}}_q^1\right)& {\mathrm{\&lambda;}}_n& ...& 0\\ \&dtri;\mathrm{MF}\left({\mathrm{\&theta;}}_p^2\right)& -\&dtri;\mathrm{MF}\left({\mathrm{\&theta;}}_q^2\right)& 0& {\mathrm{\&lambda;}}_n& ...\\ .& .& .& .& .\\ .& .& .& .& .\\ .& .& .& .& .\\ \&dtri;\mathrm{MF}\left({\mathrm{\&theta;}}_p^k\right)& -\&dtri;\mathrm{MF}\left({\mathrm{\&theta;}}_q^k\right)& 0& ...& {\mathrm{\&lambda;}}_n\end{array}\right]\&times;\left[\begin{array}{c}{\mathrm{ZD}}_p\\ {\mathrm{ZD}}_q\\ {{\mathrm{\&Delta;}\&dtri;N}_1}^1\\ \mathrm{\&Delta;}\&dtri;{N_1}^2\\ .\\ .\\ .\\ {{\mathrm{\&Delta;}\&dtri;N}_1}^k\end{array}\right]$

In the formula, MF () is the troposphere mapping function; λ _n, λ _wIt is respectively the wavelength of narrow lane and wide lane observation;

Be the combination of no ionosphere;

Be wide lane ambiguity; f ₁, f ₂Frequency for L1 and L2;

Be that two differences are defended distance; P, q are the reference station numbering; K+1 is the observation satellite number;

Adopt sequential adjustment to carry out the two difference of L1 carrier wave blur level

Resolve, the sequential adjustment calculation method is as follows:

Be located at t _kHave m+1 satellite epoch, and n is arranged _k* 1 observation vector L _k, corresponding covariance matrix is Q _k, weight matrix is

At t _K-1Obtain the model parameter vector estimated value epoch

Corresponding covariance matrix is Q _K-1, error equation is:

$V_k=A_k-{\hat{X}}_k-L_k$

In the formula:

Be n _k* (m+2) design matrix;

Be n _k* 1 observing matrix;

${\hat{X}}_k={\left[\begin{array}{cccc}{\mathrm{ZD}}_p& {\mathrm{ZD}}_q& {\mathrm{\&Delta;}\&dtri;N}_1& ...\end{array}\right]}^T$ Be (m+2) * 1 state estimation vector;

It is as follows to resolve process:

$\left\{\begin{array}{c}{P}_{{\hat{X}}_k}=A_k^T{P}_k{A}_k+P_{\widehat{X_{k-1}}}\\ P_{L_k}=A_k^T{P}_k{L}_k+P_{L_{k-1}}\\ {\hat{X}}_k=P_{{\hat{X}}_k}^{-1}{P}_{L_k}=P_{{\hat{X}}_k}^{-1}(A_k^T{P}_k{L}_k+P_{\widehat{X_{k-1}}}\widehat{X_{k-1}})\end{array}\right.$

Initial value is $P_{{\hat{X}}_1}=A_1^T{P}_1{A}_1,$ $P_{L_1}=A_1^T{P}_1{L}_1;$

By above-mentioned sequential adjustment method, can determine the two difference of L1 blur level

The two difference of L2 blur level: ${\mathrm{\&Delta;}\&dtri;N}_2={\mathrm{\&Delta;}\&dtri;N}_1-{\mathrm{\&Delta;}\&dtri;N}_w;$

(4) network checks of the two difference of L1, L2 blur level correctness:

When adopting the Delaunay triangulation network, with triangle for resolving the unit substantially, article three, baseline is chosen identical reference satellite and is carried out two subtractive combinations, then for three baselines that resolve the unit in the network arbitrarily, all there is following relation in their corresponding blur level, concerns below satisfying that the two difference of L1, L2 blur leveles are correct:

${\mathrm{\&Delta;}\&dtri;N}_{\mathrm{AB}}^{\mathrm{ij}}+{\mathrm{\&Delta;}\&dtri;N}_{\mathrm{BC}}^{\mathrm{ij}}+{\mathrm{\&Delta;}\&dtri;N}_{\mathrm{CA}}^{\mathrm{ij}}=0.$

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