CN102650692B - Method for detecting and repairing cycle slip by utilizing BeiDou three-frequency observed quantity - Google Patents

Abstract

The invention discloses a method for detecting and repairing a cycle slip by utilizing a BeiDou three-frequency observed quantity. The method mainly comprises the following steps of: 1, performing linear combination by utilizing the three-frequency observed quantity under the condition of providing a three-frequency signal by a BeiDou satellite navigation system, and constructing a combination noise detection quantity by selecting proper combination coefficients to detect the cycle slip; 2, after the cycle slip is detected, calculating and screening to obtain three sets of combination coefficients with superior performance in a pseudo-range carrier phase combination method, and calculating and repairing the cycle slip by utilizing the pseudo-range carrier phase combination method; and 3, finally, performing verification on a cycle-slip repairing effect by utilizing the combination noise detection quantity. The method for detecting and repairing the cycle slip is not related to the motion state of a carrier, can be used for reliably detecting and repairing the minimum cycle slip of which the time of losing lock reaches up to 30 seconds and can be used for detecting and repairing the cycle slip by the zero-difference, single-difference or double-difference carrier phase observed quantity when static measurement or dynamic measurement is performed.

Description

The method of utilizing the Big Dipper three observed quantities frequently to carry out Detection of Cycle-slip and reparation

Technical field

The present invention relates to satellite navigation precision positioning technology field, the method for particularly utilizing Beidou satellite navigation system three observed quantities frequently to carry out Detection of Cycle-slip and reparation in carrier phase measurement.

Background technology

Detection of Cycle-slip is the gordian technique of carrying out hi-Fix based on carrier phase observed quantity with repairing.The principle of satellite navigation location is: in the time that satellite position is known, can calculate the geographic position of receiver by measuring multi-satellite to the distance of same receiver.Receive function and from every satellite-signal, obtain pseudorange, carrier phase, the observed quantity of Doppler's three types.Carrier phase observation data is made up of decimal three parts of initial complete cycle unknown number, carrier phase complete cycle number and not enough complete cycle.Wherein fraction part is to be obtained by receiver phase detector, and integral part is to be obtained by receiver counter.Due to the blocking of buildings or trees etc., ionosphere electronic behavior is violent, the high dynamic mobility of carrier, multipath effect, low elevation angle satellite, the inconsiderate congruent reason of receiver embedded software design, can cause signal losing lock, cause complete cycle miscount, thereby produce so-called " cycle slip " phenomenon.Cycle slip has been introduced the deviation of complete cycle number to the initial blur level of phase observations amount, if cycle slip can not be found in time and correctly process, by follow-up long lasting effect epoch of positioning result.Only the cycle slip of a week will cause the positioning error of tens of centimetres.This is unacceptable for high-acruracy survey, therefore, needs a kind of Detection of Cycle-slip and restorative procedure reliably.

Current existing Detection of Cycle-slip/restorative procedure roughly can be divided into two classes:

First kind method both can be for single-frequency observed quantity, again can be for multi-frequency observation amount, as Kalman filtering, doppler shift method, improved three poor methods, least square Detection of Gross Errors method etc.The method of Kalman filtering is only applicable to carrier and makes uniform motion and the shorter situation of time of losing lock; Doppler method requires carrier to make uniform motion; Improved three poor methods, least square Detection of Gross Errors rule require to have at least 4 satellite-signals there is no cycle slip.First kind method is not suitable for the kinetic measurement that observing environment is complicated and changeable.

Equations of The Second Kind method need adopt the dual-frequency observation of short baseline, as Ionosphere Residual Error method, pseudorange combination carrier phase observation method etc.Ionosphere Residual Error method and pseudorange combination carrier phase observation method are the common methods of double frequency Detection of Cycle-slip and reparation, even if carrier does variable motion, and time of losing lock exceedes a few minutes, still can more effectively survey and repair cycle slip.But, it only utilizes the double frequency information of single satellite to repair cycle slip, and reliability is poor.

Visible said method all has some limitations.

Summary of the invention

(1) technical matters that will solve

The technical problem to be solved in the present invention is: in carrier phase measurement, how to utilize the three frequency signals that Beidou satellite navigation system is broadcast to realize reliable, sensitive Detection of Cycle-slip and reparation.Make the motion state of detection and reparation for cycle slips and carrier irrelevant, and the cycle slip of can detection and repair time of losing lock growing.

(2) technical scheme

For solving the problems of the technologies described above, the invention provides a kind of method of utilizing Beidou satellite navigation system three observed quantities frequently to carry out Detection of Cycle-slip and reparation, comprise the following steps:

S1: tectonic association walkaway amount is surveyed cycle slip;

S2: detect after cycle slip, by the calculating of pseudorange combination carrier phase observation method and reparation cycle slip;

S3: adopt the combination walkaway amount in described step S1 to verify the effect of cycle slip reparation.

Wherein, described step S1 specifically comprises:

S1.1: tectonic association walkaway amount.

The carrier phase observation equation of Beidou satellite navigation system is:

In formula: subscript i represents i the carrier wave on frequency, span is 1,2,3; Φ _i, for the phase observations amount of carrier wave i, unit is respectively rice, week; λ _ifor the wavelength of carrier wave i, unit is rice; N _ifor the integer ambiguity of carrier wave i; Dt _s, dt _rbe respectively satellite clock correction, receiver clock correction, unit is second; C is the light velocity, and unit is meter per second; for the upper corresponding ionosphere delay of carrier wave i, unit is rice; f _ifor the frequency of carrier wave i, unit is hertz; d _tropfor tropospheric retardation, unit is rice; M _{Φ i}for the multipath effect of carrier phase on i frequency, unit is rice; ε _{Φ i}for the observation noise of carrier phase, unit is rice.

First, tectonic association observed quantity is as follows:

${\mathrm{\Φ}}_{\mathrm{\ϵ}}=w_1\·{\mathrm{\Φ}}_1+w_2\·{\mathrm{\Φ}}_2+w_3\·{\mathrm{\Φ}}_3$

$=(w_1+w_2+w_3)(\mathrm{\ρ}+C\·{\mathrm{dt}}_r-C\·{\mathrm{dt}}_s+d_{\mathrm{orb}}+d_{\mathrm{trop}})-(\frac{w_1}{f_1^2}+\frac{w_2}{f_2^2}+\frac{w_3}{f_3^2})\·K$

$+(w_1{N}_1{\mathrm{\λ}}_1+w_2{N}_2{\mathrm{\λ}}_2+w_3{N}_3{\mathrm{\λ}}_3)+w_1{\mathrm{\ϵ}}_{\mathrm{\Φ}1}+w_2{\mathrm{\ϵ}}_{\mathrm{\Φ}2}+w_3{\mathrm{\ϵ}}_{\mathrm{\Φ}3}$

Order:

$\left\{\begin{array}{c}{w}_1+w_2+w_3=0\\ w_1+\frac{f_1^2}{f_2^2}{w}_2+\frac{f_1^2}{f_3^2}{w}_3=0\end{array}\right.$

So combination observation amount can be expressed as:

Φ _ε＝(w ₁N ₁λ ₁+w ₂N ₂λ ₂+w ₃N ₃λ ₃)+w ₁ε _Φ1+w ₂ε _Φ2+w ₃ε _Φ3

To combine noise front and back difference epoch as cycle slip detection limit, be called combination walkaway amount, that is:

δΦ _ε＝(w ₁δN ₁λ ₁+w ₂δN ₂λ ₂+w ₃δN ₃λ ₃)+w ₁δε _Φ1+w ₂δε _Φ2+w ₃δε _Φ3

Wherein, δ represents time difference, δ N ₁, δ N ₂, δ N ₃represent respectively three cycle slips on carrier wave, while thering is no cycle slip, δ N ₁, δ N ₂, δ N ₃be 0, if there is cycle slip, w ₁δ N ₁λ ₁+ w ₂δ N ₂λ ₂+ w ₃δ N ₃λ ₃to appear at δ Φ with the form of rough error _εin sequence.

S1.2: determine combination coefficient w ₁, w ₂, w ₃

For the geometric distance in cancellation observed quantity, satellite clock correction, receiver clock correction, ionosphere delay and tropospheric delay etc., combination coefficient w ₁, w ₂, w ₃should meet following condition:

$\left\{\begin{array}{c}{w}_1+w_2+w_3=0\\ w_1+\frac{f_1^2}{f_2^2}{w}_2+\frac{f_1^2}{f_3^2}{w}_3=0\end{array}\right.$

Make w ₁=1, have:

$w_2=\frac{1-f_1^2/f_3^2}{f_1^2/f_3^2-f_1^2/f_2^2}\≈3.257$

$w_3=\frac{1-f_1^2/f_2^2}{f_1^2/f_2^2-f_1^2/f_3^2}\≈-4.257;$

S1.3: determine the threshold value that judges whether to occur cycle slip.

Suppose that each carrier wave observation noise is uncorrelated in time, ignore ionosphere variable quantity impact, according to law of propagation of errors, δ Φ _εroot mean square can be expressed as:

${\mathrm{\σ}}_{{\mathrm{\δ\Φ}}_{\mathrm{\ϵ}}}=\sqrt{2}\·\sqrt{w_1^2{\mathrm{\σ}}_{{\mathrm{\ϵ}}_{\mathrm{\Φ}1}}^2+w_2^2{\mathrm{\σ}}_{{\mathrm{\ϵ}}_{\mathrm{\Φ}2}}^2+w_3^2{\mathrm{\σ}}_{{\mathrm{\ϵ}}_{\mathrm{\Φ}3}}^2}$

Wherein, reflect the noise effect of front and back time differences epoch.

If each frequency carrier wave observation noise variance is equal, above formula can further be expressed as:

${\mathrm{\σ}}_{\mathrm{\δ}{\mathrm{\Φ}}_{\mathrm{\ϵ}}}=\sqrt{2}\·\sqrt{w_1^2+w_2^2+w_3^2}\·{{\mathrm{\σ}}_{\mathrm{\ϵ}}}^2$

σ _ε ²conventionally be taken as 0.01 week by empirical statistics value, 2 millimeters.

In addition, also can utilize without the carrier data under cycle slip condition real-time statistics δ Φ _εroot mean square:

${\mathrm{\σ}}_{{\mathrm{\δ\Φ}}_{\mathrm{\ϵ}}}=\sqrt{\frac{\underset{k=0}{\overset{n}{\mathrm{\Σ}}}{\mathrm{\δ\Φ}}_{\mathrm{\ϵ},k}^2}{n}}$

In formula represent the combination walkaway amount δ Φ of k epoch _εsquare.If in a certain epoch, δ Φ _εmeet following formula, think and have cycle slip to occur

${\mathrm{\δ\Φ}}_{\mathrm{\ϵ}}>t\·{\mathrm{\σ}}_{{\mathrm{\δ\Φ}}_{\mathrm{\ϵ}}}$

Wherein, t=3 (99.7% degree of confidence).

Wherein, described step S2 specifically comprises:

S2.1: structure three pseudorange combination carrier phase observation observed quantity frequently.

Three frequency carrier wave Φ _{i, j, k}with three frequency pseudorange P _{a, b, c}combination observation equation is as follows:

$P_{a,b,c}=\mathrm{\ρ}(t_s,t_r)+C({\mathrm{dt}}_r-{\mathrm{dt}}_s)+d_{\mathrm{orb}}+d_{\mathrm{trop}}+{\mathrm{\β}}_{a,b,c}\·\frac{K}{f_1^2}+{\mathrm{\ϵ}}_{P_{a,b,c}}$

Wherein, i, j, k represents three frequency combination carrier phase observation coefficients; A, b, c represents three frequency pseudorange combination coefficients; Dt _s, dt _rbe respectively satellite clock correction, receiver clock correction, unit is second; C is the light velocity, and unit is meter per second; for the corresponding ionosphere delay of each carrier wave, unit is rice; β _{i, j, k}for the combination coefficient of ionosphere delay; d _tropfor tropospheric retardation, unit is rice; N _{i, j, k}for combination initial integer ambiguity; for combination carrier phase observation observation noise, unit is rice.

By Φ _{i, j, k}and P _{a, b, c}two formulas are subtracted each other can obtain initial integer ambiguity N _{i, j, k}:

$N_{\mathrm{ijk}}=\frac{{\mathrm{\Φ}}_{i,j,k}-P_{\mathrm{abc}}}{{\mathrm{\λ}}_{\mathrm{ijk}}}-({\mathrm{\β}}_{i,j,k}+{\mathrm{\β}}_{a,b,c})\·\frac{K}{f_1^2}\·\frac{1}{{\mathrm{\λ}}_{\mathrm{ijk}}}+\frac{{\mathrm{\ϵ}}_{{\mathrm{\Φ}}_{i,j,k}}-{\mathrm{\ϵ}}_{P_{\mathrm{abc}}}}{{\mathrm{\λ}}_{\mathrm{ijk}}}$

To N _ijkcarry out intercropping epoch poor, obtain the integer ambiguity difference between epoch:

${\mathrm{\δN}}_{\mathrm{ijk}}=\frac{{\mathrm{\δ\Φ}}_{i,j,k}-{\mathrm{\δP}}_{\mathrm{abc}}}{{\mathrm{\λ}}_{\mathrm{ijk}}}-\frac{{\mathrm{\β}}_{i,j,k}+{\mathrm{\β}}_{a,b,c}}{{\mathrm{\λ}}_{\mathrm{ijk}}}\·\frac{\mathrm{\δK}}{f_1^2}+\frac{{\mathrm{\δ\ϵ}}_{{\mathrm{\Φ}}_{i,j,k}}-{\mathrm{\δ\ϵ}}_{P_{\mathrm{abc}}}}{{\mathrm{\λ}}_{\mathrm{ijk}}}$

Wherein, δ represents difference between epoch;

If three groups of combination carrier phase observation coefficients are (i ₁, j ₁, k ₁), (i ₂, j ₂, k ₂), (i ₃, j ₃, k ₃), and the cycle slip round values of establishing three combination observation amounts is respectively the relation between itself and each carrier phase cycle slip value is as follows:

$y=\left[\begin{array}{c}{\mathrm{\δN}}_{i_1{j}_1{k}_1}\\ {\mathrm{\δN}}_{i_2{j}_2{k}_2}\\ {\mathrm{\δN}}_{i_3{j}_3{k}_3}\end{array}\right]=\left[\begin{array}{ccc}{i}_1& j_1& k_1\\ i_2& j_2& k_2\\ i_3& j_3& k_3\end{array}\right]\left[\begin{array}{c}{\mathrm{\δN}}_1\\ {\mathrm{\δN}}_2\\ {\mathrm{\δN}}_3\end{array}\right]=\mathrm{Hx}---\left(1\right)$

Wherein, δ N ₁, δ N ₂, δ N ₃be respectively carrier wave f ₁, f ₂, f ₃on cycle slip value, require H matrix's reversibility, and H inverse of a matrix matrix element is also round values entirely;

S2.2: screen three groups of combination coefficients (i, j, k), (a, b, c) is:

(0，-1，1)，(0，1，1)

(-1，-5，6)，(1，1，1)

(-3，6，-2)，(1，1，1)

To combine cycle slip valuation δ N _{0 ,-1,1}, δ N _{-1 ,-5,6}, δ N _{-3,6 ,-2}substitution formula (1), solves three cycle slip value δ N in frequency ₁, δ N ₂, δ N ₃, available δ N ₁, δ N ₂, δ N ₃repair the cycle slip in carrier phase observed quantity.

Wherein, described step S3 specifically comprises:

S3.1: utilize described δ N ₁, δ N ₂, δ N ₃recalculate the combination walkaway amount in step S1, be called the combination walkaway amount of repairing, as shown in the formula:

δΦ′ _ε＝δΦ _ε-(w ₁δN ₁λ ₁+w ₂δN ₂λ ₂+w ₃δN ₃λ ₃)

Wherein, δ Φ _εfor preprosthetic combination walkaway amount, δ Φ ' _εfor the combination walkaway amount after repairing.

S3.2: to the combination walkaway amount δ Φ ' after repairing _εverify,

${\mathrm{\&delta;\&Phi;}}_{\mathrm{\&epsiv;}}^{\&prime;}<3\&CenterDot;{\mathrm{\&sigma;}}_{{\mathrm{\&delta;\&Phi;}}_{\mathrm{\&epsiv;}}}$

If above formula is set up, think that cycle slip valuation calculating is correct, otherwise mistake.

(3) beneficial effect

Cycle Slips Detection in the present invention has utilized Beidou satellite navigation system to broadcast three advantages of signals frequently, can form the combination observation amount of good characteristics such as having more long wavelength, less noise, less ionosphere effect.The minimum cycle slip that the combination walkaway amount proposing can detect is 1 week.In the time that ionosphere rate of change is less than 4 cel, the pseudorange combination carrier phase observation observed quantity filtering out can be calculated reliably and repair time of losing lock and be reached the cycle slip of 30 seconds.Precision and the reliability of detection and reparation for cycle slips are improved.

Brief description of the drawings

Fig. 1 is a kind of method flow diagram that utilizes Beidou satellite navigation system three observed quantities frequently to carry out Detection of Cycle-slip and reparation of the embodiment of the present invention;

Fig. 2 is the process flow diagram of tectonic association walkaway amount in Fig. 1 step S101;

Fig. 3 is the computation process figure of threshold value while surveying cycle slip in Fig. 1 step S101;

Fig. 4 is the procedure chart that carries out Detection of Cycle-slip in Fig. 1 step S101 by combination walkaway amount;

Fig. 5 utilizes pseudorange carrier combination to calculate and repair the procedure chart of cycle slip in Fig. 1 step S102;

Fig. 6 utilizes combination walkaway amount to verify whether successfully processing procedure figure of cycle slip calculating in Fig. 1 step S103.

Embodiment

Below in conjunction with drawings and Examples, the specific embodiment of the present invention is described in further detail.Following examples are used for illustrating the present invention, but are not used for limiting the scope of the invention.

As shown in Figure 1, the method for utilizing Beidou satellite navigation system three observed quantities frequently to carry out Detection of Cycle-slip and reparation of the present invention comprises:

Step S101, utilizes combination walkaway amount to survey cycle slip, specifically comprises:

1, according to the carrier phase observation equation of Beidou satellite navigation system, tectonic association walkaway amount, as shown in Figure 2.

Wherein, the carrier phase observation equation of Beidou satellite navigation system is:

In formula (2), subscript i represents i frequency carrier wave, and span is 1,2,3; Φ _i, for the phase observations amount of carrier wave i, unit is respectively rice, week; λ _ifor the wavelength of carrier wave i, unit is rice; N _ifor the integer ambiguity of carrier wave i; Dt _s, dt _rbe respectively satellite clock correction, receiver clock correction, unit is second; C is that light velocity unit is meter per second; for the corresponding ionosphere delay of carrier wave i, unit is rice; f _ifor the frequency of carrier wave i, unit is hertz; d _tropfor tropospheric retardation, unit is rice; M _{Φ i}for the multipath effect of carrier phase on i frequency, unit is rice; ε _{Φ i}for the observation noise of carrier phase, unit is rice;

Tectonic association observed quantity is:

${\mathrm{\&Phi;}}_{\mathrm{\&epsiv;}}=w_1\&CenterDot;{\mathrm{\&Phi;}}_1+w_2\&CenterDot;{\mathrm{\&Phi;}}_2+w_3\&CenterDot;{\mathrm{\&Phi;}}_3$

$=(w_1+w_2+w_3)(\mathrm{\&rho;}+C\&CenterDot;{\mathrm{dt}}_r-C\&CenterDot;{\mathrm{dt}}_s+d_{\mathrm{orb}}+d_{\mathrm{trop}})-(\frac{w_1}{f_1^2}+\frac{w_2}{f_2^2}+\frac{w_3}{f_2^2})\&CenterDot;K---\left(3\right)$

$+(w_1{N}_1{\mathrm{\&lambda;}}_1+w_2{N}_2{\mathrm{\&lambda;}}_2+w_3{N}_3{\mathrm{\&lambda;}}_3)+w_1{\mathrm{\&epsiv;}}_{\mathrm{\&Phi;}1}+w_2{\mathrm{\&epsiv;}}_{\mathrm{\&Phi;}2}+w_3{\mathrm{\&epsiv;}}_{\mathrm{\&Phi;}3}$

For the geometric distance in cancellation observed quantity, satellite clock correction, receiver clock correction etc., order:

$\left\{\begin{array}{c}{w}_1+w_2+w_3=0\\ \frac{w_1}{f_1^2}+\frac{w_2}{f_2^2}+\frac{w_3}{f_3^2}=0\end{array}\right.---\left(4\right)$

So the observed quantity of combination noise is further written as:

Φ _ε＝(w ₁N ₁λ ₁+w ₂N ₂λ ₂+w ₃N ₃λ ₃)+w ₁ε _Φ1+w ₂ε _Φ2+w ₃ε _Φ3 (5)

To combine noise front and back difference epoch as cycle slip detection limit, be called combination walkaway amount:

δΦ _ε＝(w ₁δN ₁λ ₁+w ₂δN ₂λ ₂+w ₃δN ₃λ ₃)+w ₁δε _Φ1+w ₂δε _Φ2+w ₃δε _Φ3 (6)

Wherein, δ represents time difference; δ N ₁, δ N ₂, δ N ₃represent respectively the cycle slip on each carrier wave, while thering is no cycle slip, its value is 0.If there is cycle slip, combination cycle slip w ₁δ N ₁λ ₁+ w ₂δ N ₂λ ₂+ w ₃δ N ₃λ ₃to appear at δ Φ with the form of rough error _εin sequence.

2, determine combination coefficient w ₁, w ₂, w ₃, make combination coefficient meet following condition:

$\left\{\begin{array}{c}{w}_1+w_2+w_3=0\\ w_1+\frac{f_1^2}{f_2^2}{w}_2+\frac{f_1^2}{f_3^2}{w}_3=0\end{array}\right.$

Make w ₁=1, have:

$w_2=\frac{1-f_1^2/f_3^2}{f_1^2/f_3^2-f_1^2/f_2^2}\&ap;3.257$

$w_3=\frac{1-f_1^2/f_2^2}{f_1^2/f_2^2-f_1^2/f_3^2}\&ap;-4.257.$

3, determine the threshold value that judges whether to occur cycle slip.

As shown in Figure 3, suppose that each carrier wave observation noise is uncorrelated in time, ignore ionosphere variable quantity impact, according to law of propagation of errors, δ Φ _εroot mean square can be expressed as:

${\mathrm{\&sigma;}}_{{\mathrm{\&delta;\&Phi;}}_{\mathrm{\&epsiv;}}}=\sqrt{2}\&CenterDot;\sqrt{w_1^2{\mathrm{\&sigma;}}_{{\mathrm{\&epsiv;}}_{\mathrm{\&Phi;}1}}^2+w_2^2{\mathrm{\&sigma;}}_{{\mathrm{\&epsiv;}}_{\mathrm{\&Phi;}2}}^2+w_3^2{\mathrm{\&sigma;}}_{{\mathrm{\&epsiv;}}_{\mathrm{\&Phi;}3}}^2}$

Wherein, reflect the noise effect of front and back time differences epoch.

If each frequency carrier wave observation noise variance is equal, above formula can further be expressed as

${\mathrm{\&sigma;}}_{\mathrm{\&delta;}{\mathrm{\&Phi;}}_{\mathrm{\&epsiv;}}}=\sqrt{2}\&CenterDot;\sqrt{w_1^2+w_2^2+w_3^2}\&CenterDot;{{\mathrm{\&sigma;}}_{\mathrm{\&epsiv;}}}^2---\left(7\right)$

σ _ε ²conventionally be taken as 0.01 week by empirical statistics value, 2 millimeters.

In addition, also can utilize without the carrier data under cycle slip condition real-time statistics δ Φ _εroot mean square:

${\mathrm{\&sigma;}}_{{\mathrm{\&delta;\&Phi;}}_{\mathrm{\&epsiv;}}}=\sqrt{\frac{\underset{k=0}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&delta;\&Phi;}}_{\mathrm{\&epsiv;},k}^2}{n}}---\left(8\right)$

In formula represent the combination walkaway amount δ Φ of k epoch _εsquare.If in a certain epoch, δ Φ _εmeet following formula, think and have cycle slip to occur.

${\mathrm{\&delta;\&Phi;}}_{\mathrm{\&epsiv;}}>t\&CenterDot;{\mathrm{\&sigma;}}_{{\mathrm{\&delta;\&Phi;}}_{\mathrm{\&epsiv;}}}$

Wherein, t=3 (99.7% degree of confidence).Get as the threshold value that judges whether cycle slip.

The all jump processes of whole detection as shown in Figure 4.

Step S102, detects after cycle slip, repairs cycle slip by pseudorange combination carrier phase observation method, as shown in Figure 5, specifically comprises:

1, structure three pseudorange combination carrier phase observation observed quantity frequently.

Pseudorange combination observation equations are as follows frequently for three frequency carrier waves and three:

$P_{a,b,c}=\mathrm{\&rho;}(t_s,t_r)+C({\mathrm{dt}}_r-{\mathrm{dt}}_s)+d_{\mathrm{orb}}+d_{\mathrm{trop}}+{\mathrm{\&beta;}}_{a,b,c}\&CenterDot;\frac{K}{f_1^2}+{\mathrm{\&epsiv;}}_{P_{a,b,c}}$

Wherein, i, j, k represents three frequency combination carrier phase observation coefficients; A, b, c represents three frequency pseudorange combination coefficients; Dt _s, dt _rbe respectively satellite clock correction, receiver clock correction, unit is second; C is the light velocity, and unit is meter per second; for the corresponding ionosphere delay of each carrier wave, unit is rice; β _{i, j, k}for the combination coefficient of ionosphere delay; d _tropfor tropospheric retardation, unit is rice; N _{i, j, k}for combination initial integer ambiguity; for combination carrier phase observation observation noise, unit is rice.

Subtract each other and can obtain by two formulas:

$N_{\mathrm{ijk}}=\frac{{\mathrm{\&Phi;}}_{i,j,k}-P_{\mathrm{abc}}}{{\mathrm{\&lambda;}}_{\mathrm{ijk}}}-({\mathrm{\&beta;}}_{i,j,k}+{\mathrm{\&beta;}}_{a,b,c})\&CenterDot;\frac{K}{f_1^2}\&CenterDot;\frac{1}{{\mathrm{\&lambda;}}_{\mathrm{ijk}}}+\frac{{\mathrm{\&epsiv;}}_{{\mathrm{\&Phi;}}_{i,j,k}}-{\mathrm{\&epsiv;}}_{P_{\mathrm{abc}}}}{{\mathrm{\&lambda;}}_{\mathrm{ijk}}}---\left(9\right)$

To N _ijkcarry out intercropping epoch poor, obtain:

${\mathrm{\&delta;N}}_{\mathrm{ijk}}=\frac{{\mathrm{\&delta;\&Phi;}}_{i,j,k}-{\mathrm{\&delta;P}}_{\mathrm{abc}}}{{\mathrm{\&lambda;}}_{\mathrm{ijk}}}-\frac{{\mathrm{\&beta;}}_{i,j,k}+{\mathrm{\&beta;}}_{a,b,c}}{{\mathrm{\&lambda;}}_{\mathrm{ijk}}}\&CenterDot;\frac{\mathrm{\&delta;K}}{f_1^2}+\frac{{\mathrm{\&delta;\&epsiv;}}_{{\mathrm{\&Phi;}}_{i,j,k}}-{\mathrm{\&delta;\&epsiv;}}_{P_{\mathrm{abc}}}}{{\mathrm{\&lambda;}}_{\mathrm{ijk}}}---\left(10\right)$

Wherein, δ represents difference between epoch;

Suppose that three groups of combination carrier phase observation coefficients are (i ₁, j ₁, k ₁), (i ₂, j ₂, k ₂), (i ₃, j ₃, k ₃), and the cycle slip round values of three combination observation amounts of hypothesis is respectively the relation between itself and each carrier phase cycle slip value is as follows:

$y=\left[\begin{array}{c}{\mathrm{\&delta;N}}_{i_1{j}_1{k}_1}\\ {\mathrm{\&delta;N}}_{i_2{j}_2{k}_2}\\ {\mathrm{\&delta;N}}_{i_3{j}_3{k}_3}\end{array}\right]=\left[\begin{array}{ccc}{i}_1& j_1& k_1\\ i_2& j_2& k_2\\ i_3& j_3& k_3\end{array}\right]\left[\begin{array}{c}{\mathrm{\&delta;N}}_1\\ {\mathrm{\&delta;N}}_2\\ {\mathrm{\&delta;N}}_3\end{array}\right]=\mathrm{Hx}---\left(11\right)$

Wherein, δ N ₁, δ N ₂, δ N ₃be respectively carrier wave f ₁, f ₂, f ₃on cycle slip value.Require H matrix's reversibility, and H inverse of a matrix matrix element is also round values entirely.Thereby can be determined the value of the cycle slip in each carrier phase by formula (11).

2, according to following (1), (2), (3), (4) principle is selected three groups of combination coefficients.

(1) combined carriers wavelength is longer, to reduce the impact of pseudorange noise;

(2) ionosphere coefficient as far as possible little, to reduce the impact of residual ionospheric delay between epoch;

(3) after carrier wave, pseudorange combination, noise is as far as possible little;

(4) three groups of combined carriers linear independences.

Screen as calculated based on mentioned above principle, by three groups of combination coefficients (i, j, k), (a, b, c) is chosen to be:

(0，-1，1)，(0，1，1)

(-1，-5，6)，(1，1，1)

(-3，6，-2)，(1，1，1)

To combine cycle slip valuation δ N _{0 ,-1,1}, δ N _{-1 ,-5,6}, δ N _{-3,6 ,-2}substitution formula (11), solves δ N ₁, δ N ₂, δ N ₃, be three cycle slip values in frequency.With the δ N solving ₁, δ N ₂, δ N ₃can repair carrier phase observation data.Emulation shows, in the situation that ionosphere rate of change is less than 4 cel (rate of change 4 cels in ionosphere are ionosphere acute variation situation), adopt combinations thereof coefficient, can calculate reliably and repair time of losing lock and reach the minimum cycle slip of 30 seconds.

Step S103, adopts the combination walkaway amount in described step S101 to verify the effect of cycle slip reparation.Specifically comprise:

With the cycle slip δ N in three calculated carrier frequencies ₁, δ N ₂, δ N ₃repair the combination walkaway amount in step S101, as shown in the formula:

δΦ′ _ε＝δΦ _ε-(w ₁δN ₁λ ₁+w ₂δN ₂λ ₂+w ₃δN ₃λ ₃) (12)

δ Φ _εfor preprosthetic combination walkaway amount, δ Φ ' _εfor the combination walkaway amount after repairing.

To the combination walkaway amount δ Φ after repairing _εverify, if δ is Φ ' _εbe less than threshold value, confirm that cycle slip valuation calculating is correct, otherwise mistake.

Above embodiment is only for illustrating the present invention; and be not limitation of the present invention; the those of ordinary skill in relevant technologies field; without departing from the spirit and scope of the present invention; can also make a variety of changes and modification; therefore all technical schemes that are equal to also belong to category of the present invention, and scope of patent protection of the present invention should be defined by the claims.

Claims (3)

1. a method of utilizing the Big Dipper three observed quantities frequently to carry out Detection of Cycle-slip and reparation, is characterized in that, comprises the following steps:

S1: utilize combination walkaway amount to survey cycle slip;

S2: detect after cycle slip, by the calculating of pseudorange combination carrier phase observation method, reparation cycle slip;

S3: adopt the combination walkaway amount in described step S1 to verify the effect of cycle slip reparation;

Described step S1 specifically comprises:

S1.1: tectonic association walkaway amount:

The carrier phase observation equation of Beidou satellite navigation system is:

In formula: subscript i represents i the carrier wave on frequency, span is 1,2,3; Φ _i, for the phase observations amount of carrier wave i, unit is respectively rice, week; λ _ifor the wavelength of carrier wave i, unit is rice; N _ifor the integer ambiguity of carrier wave i; Dt _s, dt _rbe respectively satellite clock correction, receiver clock correction, unit is second; C is the light velocity, and unit is meter per second; for the upper corresponding ionosphere delay of carrier wave i, unit is rice; f _ifor the frequency of carrier wave i, unit is hertz; d _tropfor tropospheric retardation, unit is rice; M _{Φ i}for the multipath effect of carrier phase on i frequency, unit is rice; ε _{Φ i}for the observation noise of carrier phase, unit is rice,

Tectonic association observed quantity as shown in the formula:

$\begin{array}{c}{\mathrm{\&Phi;}}_{\mathrm{\&epsiv;}}=w_1\&CenterDot;{\mathrm{\&Phi;}}_1+w_2\&CenterDot;{\mathrm{\&Phi;}}_2+w_3\&CenterDot;{\mathrm{\&Phi;}}_3\\ =(w_1+w_2+w_3)(\mathrm{\&rho;}+C\&CenterDot;{\mathrm{dt}}_r-C\&CenterDot;{\mathrm{dt}}_s+d_{\mathrm{orb}}+d_{\mathrm{trop}})-(\frac{w_1}{{f_1}^2}+\frac{w_2}{{f_2}^2}+\frac{w_3}{{f_3}^2})\&CenterDot;K\\ +(w_1{N}_1{\mathrm{\&lambda;}}_1+w_2{N}_2{\mathrm{\&lambda;}}_2+w_3{N}_3{\mathrm{\&lambda;}}_3)+w_1{\mathrm{\&epsiv;}}_{\mathrm{\&Phi;}1}+w_2{\mathrm{\&epsiv;}}_{\mathrm{\&Phi;}2}+w_3{\mathrm{\&epsiv;}}_{\mathrm{\&Phi;}3}\end{array}$

Order:

$\left\{\begin{array}{c}{w}_1+w_2+w_3=0\\ \frac{w_1}{{f_1}^2}+\frac{w_2}{{f_2}^2}+\frac{w_3}{{f_3}^2}=0\end{array}\right.$

Combination observation amount can further be expressed as:

Φ _ε＝(w ₁N ₁λ ₁+w ₂N ₂λ ₂+w ₃N ₃λ ₃)+w ₁ε _Φ1+w ₂ε _Φ2+w ₃ε _Φ3

By poor epoch before and after combination observation amount, as shown in the formula:

δΦ _ε＝(w ₁δN ₁λ ₁+w ₂δN ₂λ ₂+w ₃δN ₃λ ₃)+w ₁δε _Φ1+w ₂δε _Φ2+w ₃δε _Φ3

Value of delta Φ _εbe called combination walkaway amount, wherein, δ represents time difference, δ N ₁, δ N ₂, δ N ₃represent respectively carrier wave f ₁, f ₂, f ₃on cycle slip, while thering is no cycle slip, δ N ₁, δ N ₂, δ N ₃be 0, if there is cycle slip, w ₁δ N ₁λ ₁+ w ₂δ N ₂λ ₂+ w ₃δ N ₃λ ₃to appear at δ Φ with the form of rough error _εin sequence;

S1.2: determine combination coefficient w ₁, w ₂, w ₃, make combination coefficient meet following condition:

$\left\{\begin{array}{c}{w}_1+w_2+w_3=0\\ w_1+\frac{{f_1}^2}{{f_2}^2}{w}_2+\frac{{f_1}^2}{{f_3}^2}{w}_3=0\end{array}\right.$

Make w ₁=1, have:

$w_2=\frac{1-{f_1}^2/{f_3}^2}{{f_1}^2/{f_3}^2-{f_1}^2/{f_2}^2}\&ap;3.257$

$w_3=\frac{1-{f_1}^2/{f_2}^2}{{f_1}^2/{f_2}^2-{f_1}^2/{f_3}^2}\&ap;-4.257;$

S1.3: according to combination walkaway amount δ Φ _εwith its root mean square relation judge whether to occur cycle slip, judgement relation is as follows:

${\mathrm{\&delta;\&Phi;}}_{\mathrm{\&epsiv;}}>t\&CenterDot;{\mathrm{\&sigma;}}_{\mathrm{\&delta;}{\mathrm{\&Phi;}}_{\mathrm{\&epsiv;}}}$

Wherein, t=3, if δ is Φ _εmeet think generation cycle slip;

Described step S2 specifically comprises:

S2.1: structure three pseudorange combination carrier phase observation observed quantity frequently,

Pseudorange combination observation equations are as follows frequently for three frequency carrier waves and three:

$P_{a,b,c}=\mathrm{\&rho;}(t_s,t_r)+C({\mathrm{dt}}_r-{\mathrm{dt}}_s)+d_{\mathrm{orb}}+d_{\mathrm{trop}}+{\mathrm{\&beta;}}_{a,b,c}\&CenterDot;\frac{K}{{f_1}^2}+{\mathrm{\&epsiv;}}_{P_{a,b,c}}$

In formula:

I, j, k represents three frequency combination carrier phase observation coefficients; A, b, c represents three frequency pseudorange combination coefficients; Dt _s, dt _rbe respectively satellite clock correction, receiver clock correction, unit is second; C is the light velocity, and unit is meter per second; β _{i, j, k}(K/f ₁ ²) be the corresponding ionosphere delay of each carrier wave, unit is rice, β _{i, j, k}for the combination coefficient of ionosphere delay; d _tropfor tropospheric retardation, unit is rice; N _{i, j, k}for combination initial integer ambiguity; for combination carrier phase observation observation noise, unit is rice,

Subtract each other and can obtain by two formulas above:

$N_{i,j,k}=\frac{{\mathrm{\&Phi;}}_{i,j,k}-P_{a,b,c}}{{\mathrm{\&lambda;}}_{i,j,k}}-({\mathrm{\&beta;}}_{i,j,k}+{\mathrm{\&beta;}}_{a,b,c})\&CenterDot;\frac{K}{{f_1}^2}\&CenterDot;\frac{1}{{\mathrm{\&lambda;}}_{i,j,k}}+\frac{{\mathrm{\&epsiv;}}_{{\mathrm{\&Phi;}}_{i,j,k}}-{\mathrm{\&epsiv;}}_{P_{a,b,c}}}{{\mathrm{\&lambda;}}_{i,j,k}}$

To N _ijkcarry out intercropping epoch poor, obtain:

${\mathrm{\&delta;N}}_{i,j,k}=\frac{{\mathrm{\&delta;\&Phi;}}_{i,j,k}-{\mathrm{\&delta;P}}_{a,b,c}}{{\mathrm{\&lambda;}}_{i,j,k}}-\frac{{\mathrm{\&beta;}}_{i,j,k}+{\mathrm{\&beta;}}_{a,b,c}}{{\mathrm{\&lambda;}}_{i,j,k}}\&CenterDot;\frac{\mathrm{\&delta;K}}{{f_1}^2}+\frac{{\mathrm{\&delta;\&epsiv;}}_{{\mathrm{\&Phi;}}_{i,j,k}}-{\mathrm{\&delta;\&epsiv;}}_{P_{a,b,c}}}{{\mathrm{\&lambda;}}_{i,j,k}}$

Wherein, δ represents difference between epoch;

Suppose that three groups of combination carrier phase observation coefficients are (i ₁, j ₁, k ₁), (i ₂, j ₂, k ₂), (i ₃, j ₃, k ₃), and the cycle slip round values of three combination observation amounts of hypothesis is respectively the relation between itself and each carrier phase cycle slip value is as follows:

$y=\left[\begin{array}{c}{\mathrm{\&delta;N}}_{i_1,j_1,k_1}\\ {\mathrm{\&delta;N}}_{i_2,j_2,k_2}\\ {\mathrm{\&delta;N}}_{i_3,j_3,k_3}\end{array}\right]=\begin{array}{c}\left[\begin{array}{ccc}{i}_1& j_1& k_1\\ i_2& j_2& k_2\\ i_3& j_3& k_3\end{array}\right]\left[\begin{array}{c}{\mathrm{\&delta;N}}_1\\ {\mathrm{\&delta;N}}_2\\ {\mathrm{\&delta;N}}_3\end{array}\right]=\mathrm{Hx}\end{array}$

Wherein, δ N ₁, δ N ₂, δ N ₃be respectively carrier wave f ₁, f ₂, f ₃on cycle slip value, require H matrix's reversibility, and H inverse of a matrix matrix element is also round values entirely, thereby can determines the valuation δ N of the cycle slip in each carrier phase ₁, δ N ₂, δ N ₃;

S2.2: calculate, screen three groups of combination coefficients (i, j, k), (a, b, c) is:

(0,-1,1),(0,1,1)

(-1,-5,6),(1,1,1)

(-3,6,-2),(1,1,1)

Solve three cycle slip value δ N in frequency ₁, δ N ₂, δ N ₃, with the δ N solving ₁, δ N ₂, δ N ₃can repair carrier phase observation data;

Described step S3 specifically comprises:

Utilize δ N ₁, δ N ₂, δ N ₃recalculate the combination walkaway amount in step S1, also claim to repair combination walkaway amount, as shown in the formula:

δΦ' _ε＝δΦ _ε-(w ₁δN ₁λ ₁+w ₂δN ₂λ ₂+w ₃δN ₃λ ₃)

Wherein, δ Φ _εfor preprosthetic combination walkaway amount, δ Φ ' _εfor the combination walkaway amount after repairing, to the combination walkaway amount δ Φ ' after repairing _εverify, if δ is Φ ' _εbe less than threshold value, think cycle slip valuation calculate correct, otherwise mistake.

2. the method for utilizing the Big Dipper three observed quantities frequently to carry out Detection of Cycle-slip and reparation as claimed in claim 1, is characterized in that, in described step S1.3 computing method be: suppose that each carrier wave observation noise is uncorrelated in time, ignore the impact of ionosphere variable quantity, according to law of propagation of errors, δ Φ _εroot mean square can be expressed as:

${\mathrm{\&sigma;}}_{{\mathrm{\&delta;\&Phi;}}_{\mathrm{\&epsiv;}}}=\sqrt{2}\&CenterDot;\sqrt{w_1^2{\mathrm{\&sigma;}}_{{\mathrm{\&epsiv;}}_{\mathrm{\&Phi;}1}}^2+w_2^2{\mathrm{\&sigma;}}_{{\mathrm{\&epsiv;}}_{\mathrm{\&Phi;}2}}^2+w_3^2{\mathrm{\&sigma;}}_{{\mathrm{\&epsiv;}}_{\mathrm{\&Phi;}3}}^2}$

Wherein, reflect the noise effect of front and back time differences epoch,

If each frequency carrier wave observation noise variance is equal, above formula can further be expressed as:

${\mathrm{\&sigma;}}_{{\mathrm{\&delta;\&Phi;}}_{\mathrm{\&epsiv;}}}=\sqrt{2}\&CenterDot;\sqrt{w_1^2+w_2^2+w_3^2}\&CenterDot;{{\mathrm{\&sigma;}}_{\mathrm{\&epsiv;}}}^2$

Wherein σ _ε ²empirical value be conventionally taken as 0.01 week, 2 millimeters.

3. the method for utilizing the Big Dipper three observed quantities frequently to carry out Detection of Cycle-slip and reparation as claimed in claim 1, is characterized in that, in described step S1.3 computing method can also be:

Utilize without the carrier data under cycle slip condition real-time statistics δ Φ _εroot mean square:

${\mathrm{\&sigma;}}_{{\mathrm{\&delta;\&Phi;}}_{\mathrm{\&epsiv;}}}=\sqrt{\frac{\underset{k=0}{\overset{n}{\mathrm{\&Sigma;}}}\mathrm{\&delta;}{\mathrm{\&Phi;}}_{\mathrm{\&epsiv;},k}^2}{n}}$

In formula, represent the combination walkaway amount δ Φ of k epoch _εsquare.