CN104570013A - Detection method of real-time GPS (Global Position System) carrier phase cycle slip for frequency taming - Google Patents

Abstract

The invention discloses a detection method of real-time GPS (Global Position System) carrier phase cycle slip for frequency taming. The detection method comprises the following steps: S1, calculating an observed value of an MW (Melbourne-Wubbena) wide lane combination, S2, estimating ambiguity of an MW wide lane, S3, calculating a cycle slip decision item, S4, calculating a cycle slip decision threshold, judging whether the cycle slip decision item exceeds the cycle slip decision threshold, and moving to Step S5 if not, S5, calculating an electron content change rate of an ionized layer of an epoch (k), S6, predicting TECR (Total Electron Content Change Rate) value of the epoch (k) according to history data, and S7, calculating a detection threshold of a TECR method, calculating the difference between a calculated value and a predicted value of the epoch (k), and judging whether the detection threshold of the TECR method is exceeded. The method is combined with a constraint condition limitation that the total electron content change rate of the ionized layer is limited in a short period, shows the same cycle slip on L1 and L2 frequency points via linear combination of a carrier phase observation equation, and covers the shortage of an MW method.

Description

A kind of detection method of real time GPS carrier phase cycle slip of taming for frequency

Technical field

The present invention relates to data processing method.More specifically, a kind of detection method of real time GPS carrier phase cycle slip of taming for frequency is related to.

Background technology

Gps carrier phase techniques, not only can realize high-precision location, mapping and navigation, in Time Transmission and frequency are tamed etc., also have important application.Frequency is tamed, carrier phase observed quantity is utilized to replace traditional C/A code observed quantity, because carrier frequency exceeds about 1000 times than C/A bit rate, can better suppression receiver thermonoise and atmosphere delay, improve the accuracy and degree of stability of taming frequency source, wherein atmosphere delay comprises ionosphere and tropospheric delay.And, due to the stability of carrier phase observed quantity, can make the frequency standard of taming within the shorter time, reach its predetermined serviceability index.

Frequency is tamed for carrier phase observed quantity, carrier phase observed quantity to keep level and smooth continuously, its cycle slip must be repaired by correct detection.Cycle slip can destroy the continuity of gps carrier phase observations amount, and L1 frequency single-revolution cycle slip can introduce the range error of about 19cm, the timing error of corresponding 0.635ns.Tame in process in frequency, occur that so large timing error will produce considerable influence to taming result, output frequency index is worsened.

In recent years, GPS real-time kinematical RTK technology and Static Precise Point Positioning PPP technology are popular research directions, and wherein carrier phase is all main observed quantity.The research of carrier phase Detection of Cycle-slip reparation has a lot, but these methods are all mainly based on dual station differential technique, is not suitable for the data processing of single station GPS.In addition, also have certain methods to be integrated based on GPS and inertial guidance data, these methods are subject to the restriction of inertial navigation system application to a great extent.A series of traditional Cycle Slips Detection, such as code phase compares, phase place Ionosphere Residual Error, Doppler's integration, and time phase difference grades, and has respective limitation.The low precision that code phase relative method is measured due to code, cannot repair the little cycle slip of 1 ~ 2 week; Doppler's integral method cannot repair little cycle slip too; Phase place Ionosphere Residual Error method to insensitive, and cannot judge which frequency is cycle slip occur in for cycle slip specific on two frequencies; Time phase, method of difference needed to carry out fitting of a polynomial interpolation of data or extrapolation on detection epoch, and fitting of a polynomial can not ensure that all detections are all successful, especially when cycle slip is less.

In addition, tame in application in frequency, Detection of Cycle-slip is demand fulfillment real-time characteristic also, can reflect in time by the characteristic variations of tame and docile frequency source, carries out taming adjustment in time to it.

Therefore, need to provide a kind of detection method of real time GPS carrier phase cycle slip of taming for frequency.

Summary of the invention

The object of the present invention is to provide a kind of detection method of real time GPS carrier phase cycle slip of taming for frequency.

For achieving the above object, the present invention adopts following technical proposals:

For a detection method for the real time GPS carrier phase cycle slip that frequency is tamed, the method comprises the steps:

S1, utilize observation equation, utilize the L1 frequency of GPS and the carrier phase observed quantity of L2 frequency and pseudo range observed quantity, calculate MW wide lane combination observation amount;

S2, according to MW wide lane combination estimation the wide lane of MW blur level;

S3, the MW of adjacent epoch wide lane ambiguity Difference Calculation cycle slip is utilized to adjudicate item [Δ N ₁(k)-Δ N ₂(k)];

S4, utilize wide lane ambiguity historical data to calculate cycle slip decision threshold, judge that cycle slip adjudicates item [Δ N ₁(k)-Δ N ₂(k)] whether exceed cycle slip decision threshold, to whether there is cycle slip epoch (k) detect, if it is process ends, if otherwise proceed to step S5;

S5, utilize GPS the observed quantity of L1 and L2 frequency carrier phase calculate epoch (k) ionosphere electron content rate of change TECR (k);

S6, the TECR value predicting epoch (k) according to TECR historical data;

S7, TECR historical data is utilized to calculate TECR method decision threshold, the calculated value of epoch (k) in step S5 and the predicted value of step S6 epoch (k) are asked difference, judge that whether difference is more than TECR method decision threshold, if it is think to there is cycle slip, if otherwise without cycle slip.

Preferably, step S1 comprises following sub-step further:

S1.1, by separate unit GPS dual-frequency receiver observation gps satellite p, calculate the carrier phase observed quantity of the L1 frequency of GPS respectively based on observation equation and pseudo range observed quantity the carrier phase observed quantity of L2 frequency and pseudo range observed quantity formula is as follows:

${\mathrm{\φ}}_1^p=\frac{{\mathrm{\ρ}}^p+c(d_t-d_{T^p})-I+T}{{\mathrm{\λ}}_1}+N_1^p$

${\mathrm{\φ}}_2^p=\frac{{\mathrm{\ρ}}^p+c(d_t-d_{T^p})-\mathrm{\γI}+T}{{\mathrm{\λ}}_2}+N_2^p$

$P_1^p={\mathrm{\ρ}}^p+c(d_t-d_{T^p})+I+T$

$P_2^p={\mathrm{\ρ}}^p+c(d_t-d_{T^p})+\mathrm{\γI}+T$

In formula, f ₁and f ₂be respectively the signal frequency of L1 and the L2 frequency of GPS, λ ₁and λ ₂be respectively the signal wavelength of L1 and the L2 frequency of GPS, ρ ^pfor the geometric distance between receiver and satellite p; d _tfor the clocking error of receiver; for the star clock error of satellite p; C is vacuum light speed; I is distance corresponding to the ionosphere time delay of the L1 frequency signal of GPS; T is distance corresponding to troposphere time delay; with the integer ambiguity of L1 and the L2 frequency of gps satellite p respectively; γ=f ₁ ²/ f ₂ ², for GPS L1 and L2 signal frequency ratio square;

S1.2, the carrier phase observed quantity utilizing L1 and the L2 frequency of GPS each epoch and pseudo range observed quantity, calculate the MW wide lane combination observation amount L of GPS _mWWL, formula is as follows:

$L_{\mathrm{MWWL}}=\frac{f_1\·{\mathrm{\λ}}_1{\mathrm{\φ}}_1^p-f_2\·{\mathrm{\λ}}_2{\mathrm{\φ}}_2^p}{f_1-f_2}-\frac{f_1\·P_1^p+f_2{P}_2^p}{f_1+f_2}.$

Preferably, estimate in step S2 that the formula of the blur level in the wide lane of MW is as follows:

$N_{\mathrm{WL}}^p=\frac{L_{\mathrm{MWWL}}}{{\mathrm{\λ}}_{\mathrm{WL}}}=[{\mathrm{\φ}}_1^p-{\mathrm{\φ}}_2^p-\frac{f_1\·P_1^p+f_2\·P_2^p}{{\mathrm{\λ}}_{\mathrm{WL}}(f_1+f_2)}]$

In formula, for wide lane ambiguity estimated value each epoch, λ _wL=c/ (f ₁-f ₂) ≈ 86cm, be wide lane wavelength.

Preferably, cycle slip judgement item [Δ N is calculated in step S3 ₁(k)-Δ N ₂(k)] formula as follows:

$[\mathrm{\Δ}{N}_1^p\left(k\right)-\mathrm{\Δ}{N}_2^p\left(k\right)]=N_{\mathrm{WL}}^p\left(k\right)-N_{\mathrm{WL}}^p(k-1).$

Preferably, in step S4, cycle slip decision threshold is the wide lane ambiguity estimated value of epoch (k) 4 times of standard variance.

Preferably, step S5 comprises following sub-step further:

S5.1, calculate the ionosphere total electron content of each epoch, formula is as follows:

$\mathrm{TEC}=\frac{{f_1}^2[({\mathrm{\λ}}_1{\mathrm{\φ}}_1^p-{\mathrm{\λ}}_2{\mathrm{\φ}}_2^p)-({\mathrm{\λ}}_1{N}_1-{\mathrm{\λ}}_2{N}_2)-b_i-b^p]}{40.3\×{10}^{16}(\mathrm{\γ}-1)}$

In formula, b _iand b ^pbe respectively two inter-frequency deviations of receiver and satellite, unit is m;

The total electron content rate of change of S5.2, calculating epoch (k), formula is as follows:

${\mathrm{TECR}}_{\mathrm{\φ}}\left(k\right)=\frac{{\mathrm{TEC}}_{\mathrm{\φ}}\left(k\right)-{\mathrm{TEC}}_{\mathrm{\φ}}(k-1)}{\mathrm{\Δt}}$

In formula, TECR _φk ionosphere total electron content rate of change that () is epoch (k); Δ t is epoch (k-1) and the time interval between epoch (k);

Ionosphere electron content rate of change TECR (k) of S5.3, calculating epoch (k), formula is as follows:

$\mathrm{TECR}\left(k\right)=\frac{{f_1}^2}{40.3\×{10}^{16}(\mathrm{\γ}-1)}\left\{{\mathrm{\λ}}_1\right[{\mathrm{\φ}}_1^p\left(k\right)-{\mathrm{\φ}}_1^p(k-1)]-{\mathrm{\λ}}_2[{\mathrm{\φ}}_2^p\left(k\right)-{\mathrm{\φ}}_2^p(k-1)\left]\right\}.$

Preferably, predict that the method for the TECR value of current epoch (k) is for setting sampling interval as 1s in step S6, before utilizing epoch (k), the data of 30s are averaged, using the TECR predicted value of this average as current epoch k.

Preferably, in step S7, TECR method decision threshold is 4 times of the standard variance in ionosphere electron content rate of change TECR (k) of epoch (k).

Beneficial effect of the present invention is as follows:

Technical scheme of the present invention is by traditional MW Detection of Cycle-slip method, combine ionosphere total electron content rate of change and change limited constraint condition restriction at short notice, by the linear combination of carrier phase observation equation, and ionosphere delay and ionosphere total electron content relational expression, by difference between high sampling rate epoch, and reasonably decision threshold is selected, identical cycle slip on L1 with L2 frequency is displayed, compensate for the deficiency of MW method, the real-time dual-frequency carrier of unit is detected more reliably convenient.Technical scheme real-time of the present invention is good, convenient and swift, is applicable to static 1s magnitude high sampling rate GPS unit dual-frequency data Detection of Cycle-slip.Tame in process in frequency, utilize carrier phase smoothing pseudo-range can effectively reduce the noise measuring the time difference, but the existence of cycle slip makes the time difference smoothly occur significantly changing.After technical scheme of the present invention detects cycle slip, can by resetting smoothing filter in time, the time difference that calculating is exported keeps continuously.

Accompanying drawing explanation

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described in further detail.

Fig. 1 illustrates the process flow diagram of the detection method of the real time GPS carrier phase cycle slip of taming for frequency.

Embodiment

In order to be illustrated more clearly in the present invention, below in conjunction with preferred embodiments and drawings, the present invention is described further.Parts similar in accompanying drawing represent with identical Reference numeral.It will be appreciated by those skilled in the art that specifically described content is illustrative and nonrestrictive, should not limit the scope of the invention with this below.

The detection method of the real time GPS carrier phase cycle slip of taming for frequency that present embodiment provides, concrete steps are:

Step1, the carrier phase observed quantity of L1 and L2 frequency calculating GPS and pseudo range observed quantity, and calculate MW wide lane combination observation amount according to the carrier phase observed quantity of L1 and the L2 frequency of GPS and pseudo range observed quantity, specifically comprise following sub-step:

Step1.1, by separate unit GPS dual-frequency receiver observation gps satellite p, calculate the carrier phase observed quantity of the L1 frequency of GPS respectively based on observation equation and pseudo range observed quantity the carrier phase observed quantity of L2 frequency and pseudo range observed quantity formula is as follows:

${\mathrm{\φ}}_1^p=\frac{{\mathrm{\ρ}}^p+c(d_t-d_{T^p})-I+T}{{\mathrm{\λ}}_1}+N_1^p$ Formula (1)

${\mathrm{\φ}}_2^p=\frac{{\mathrm{\ρ}}^p+c(d_t-d_{T^p})-\mathrm{\γI}+T}{{\mathrm{\λ}}_2}+N_2^p$ Formula (2)

$P_1^p={\mathrm{\ρ}}^p+c(d_t-d_{T^p})+I+T$ Formula (3)

$P_2^p={\mathrm{\ρ}}^p+c(d_t-d_{T^p})+\mathrm{\γI}+T$ Formula (4)

In formula, f ₁and f ₂be respectively the signal frequency of L1 and the L2 frequency of GPS, λ ₁and λ ₂be respectively the signal wavelength of L1 and the L2 frequency of GPS, ρ ^pfor the geometric distance between receiver and satellite p; d _tfor the clocking error of receiver; for the star clock error of satellite p; C is vacuum light speed; I is distance corresponding to the ionosphere time delay of the L1 frequency signal of GPS; T is distance corresponding to troposphere time delay; with the integer ambiguity of L1 and the L2 frequency of gps satellite p respectively; γ=f ₁ ²/ f ₂ ², for GPS L1 and L2 signal frequency ratio square;

Step1.2, the carrier phase observed quantity utilizing L1 and the L2 frequency of GPS each epoch and pseudo range observed quantity, calculate the MW wide lane combination observation amount L of GPS _mWWL, formula is as follows:

$L_{\mathrm{MWWL}}=\frac{f_1\·{\mathrm{\λ}}_1{\mathrm{\φ}}_1^p-f_2\·{\mathrm{\λ}}_2{\mathrm{\φ}}_2^p}{f_1-f_2}-\frac{f_1\·P_1^p+f_2{P}_2^p}{f_1+f_2}$ Formula (5)

MW combination is a kind of Cycle Slips Detection, can eliminate the impact of air (comprising ionosphere and troposphere) time delay, geometric distance, satellite and receiver clock-offsets.

Step2, estimate the blur level of each MW epoch wide lane combination observation amount

According to formula (5), utilize MW wide lane combination observation amount L _mWWLdivided by wide lane wavelength X _wL, wide lane ambiguity estimated value each epoch can be obtained formula is as follows:

$N_{\mathrm{WL}}^p=\frac{L_{\mathrm{MWWL}}}{{\mathrm{\λ}}_{\mathrm{WL}}}=[{\mathrm{\φ}}_1^p-{\mathrm{\φ}}_2^p-\frac{f_1\·P_1^p+f_2\·P_2^p}{{\mathrm{\λ}}_{\mathrm{WL}}(f_1+f_2)}]$ Formula (6)

In formula, λ _wL=c/ (f ₁-f ₂) ≈ 86cm, be wide lane wavelength;

Step3, the wide lane ambiguity of MW according to epoch (k) and the epoch adjacent with epoch (k) with difference Calculation cycle slip item judgement item [Δ N ₁-Δ N ₂]

Suppose in epoch (k-1) without cycle slip, or cycle slip is repaired, and in epoch (k), L1 and the L2 frequency carrier phase observed quantity of GPS with on all there is cycle slip with after cycle slip is detected and repairs, epoch (k), correct carrier phase observed quantity was:

$\widehat{{\mathrm{\φ}}_1^p}\left(k\right)={\mathrm{\φ}}_1^p\left(k\right)+\mathrm{\Δ}{N}_1^p\left(k\right)$ Formula (7)

$\widehat{{\mathrm{\φ}}_2^p}\left(k\right)={\mathrm{\φ}}_2^p\left(k\right)+\mathrm{\Δ}{N}_2^p\left(k\right)$ Formula (8)

In formula, with be respectively L1 and L2 frequency carrier phase observed quantity correct after repairing cycle slip.

By formula (5) ~ (8), calculate cycle slip judgement item formula is as follows:

$[\mathrm{\Δ}{N}_1^p\left(k\right)-\mathrm{\Δ}{N}_2^p\left(k\right)]=N_{\mathrm{WL}}^p\left(k\right)-N_{\mathrm{WL}}^p(k-1)$ Formula (9)

MW wide lane cycle slip judgement item estimation in formula (9) estimates according to the Dynamic data exchange of each epoch.

Step4, calculate cycle slip decision threshold by wide lane ambiguity historical data and detect

In the wide lane ambiguity of calculating time, the factors such as pseudorange noise make the data calculated there is uncertainty.Like this, cycle slip judgement item also there is noise, need to utilize historical data and statistical method to judge.

According to the wide lane ambiguity that first 30 calculate epoch calculate its standard variance, formula is as follows:

First, calculate mathematical expectation:

$E\left[N_{\mathrm{WL}}^p\left(k\right)\right]=\stackrel{\‾}{N_{\mathrm{WL}}^p\left(k\right)}=\stackrel{\‾}{N_{\mathrm{WL}}^p(k-1)}+\frac{1}{30}[N_{\mathrm{WL}}^p\left(k\right)-\stackrel{\‾}{N_{\mathrm{WL}}^p(k-1)}]$ Formula (10)

Then, calculate mathematical expectation:

$E\left[{\left(N_{\mathrm{WL}}^p\left(k\right)\right)}^2\right]=E\left[{\left(N_{\mathrm{WL}}^p(k-1)\right)}^2\right]+\frac{1}{30}\{{\left(N_{\mathrm{WL}}^p\left(k\right)\right)}^2-E[{\left(N_{\mathrm{WL}}^p(k-1)\right)}^2\left]\right\}$ Formula (11)

Utilize the wide lane ambiguity of two formulae discovery epoch (k) standard variance:

${\mathrm{\σ}}_{N_{\mathrm{WL}}^p\left(k\right)}^2=E\left[{\left(N_{\mathrm{WL}}^p\left(k\right)\right)}^2\right]-{\left(\stackrel{\‾}{N_{\mathrm{WL}}^p\left(k\right)}\right)}^2$ Formula (12)

In judging process, using calculate 4 times of standard variances as the thresholding of preliminary Detection of Cycle-slip, if cycle slip judgement item is greater than thresholding, then illustrate to there is cycle slip, and the cycle slip that L1 and L2 frequency occurs is unequal; If cycle slip judgement item is less than or equal to thresholding, then need to be adjudicated further by subsequent step.

Step5, utilize GPS the observed quantity of L1 and L2 frequency carrier phase calculate ionosphere electron content rate of change TECR

By ionosphere time delay and ionosphere total electron content TEC relational expression

$I=40.3\×{10}^{16}\frac{\mathrm{TEC}}{{f_1}^2}$ Formula (13)

In conjunction with carrier phase observation equation, i.e. formula (1) and (2), can calculate the ionosphere total electron content of each epoch from dual-frequency carrier observed quantity, formula is as follows:

$\mathrm{TEC}=\frac{{f_1}^2[({\mathrm{\λ}}_1{\mathrm{\φ}}_1^p-{\mathrm{\λ}}_2{\mathrm{\φ}}_2^p)-({\mathrm{\λ}}_1{N}_1-{\mathrm{\λ}}_2{N}_2)-b_i-b^p]}{40.3\×{10}^{16}(\mathrm{\γ}-1)}$ Formula (14)

In formula, b _iand b ^pbe respectively two inter-frequency deviations of receiver and satellite, unit is m.These two values all quite stable within several days time.The gps data process sampling interval of taming for frequency is 1s.Therefore, constant can be it can be used as.

By epoch (k) and the ionosphere total electron content of epoch (k-1) are made difference, total electron content rate of change can be obtained

${\mathrm{TECR}}_{\mathrm{\φ}}\left(k\right)=\frac{{\mathrm{TEC}}_{\mathrm{\φ}}\left(k\right)-{\mathrm{TEC}}_{\mathrm{\φ}}(k-1)}{\mathrm{\Δt}}$ Formula (15)

In formula, TECR _φk ionosphere total electron content rate of change that () is epoch (k); Δ t is epoch (k-1) and the time interval between epoch (k), is 1s herein.

Formula (14) is substituted into formula (15), can obtain

$\mathrm{TECR}\left(k\right)=\frac{{f_1}^2}{40.3\×{10}^{16}(\mathrm{\γ}-1)}\left\{{\mathrm{\λ}}_1\right[{\mathrm{\φ}}_1^p\left(k\right)-{\mathrm{\φ}}_1^p(k-1)]-{\mathrm{\λ}}_2[{\mathrm{\φ}}_2^p\left(k\right)-{\mathrm{\φ}}_2^p(k-1)]-[{\mathrm{\λ}}_1\mathrm{\Δ}{N}_1^p\left(k\right)-{\mathrm{\λ}}_2\mathrm{\Δ}{N}_2^p\left(k\right)\left]\right\}$ Formula (16)

In formula, with for L1 and the L2 frequency carrier phase observed quantity of GPS during epoch (k) with the cycle slip of upper appearance.When without cycle slip, formula (16) can be reduced to

$\mathrm{TECR}\left(k\right)=\frac{{f_1}^2}{40.3\×{10}^{16}(\mathrm{\γ}-1)}\left\{{\mathrm{\λ}}_1\right[{\mathrm{\φ}}_1^p\left(k\right)-{\mathrm{\φ}}_1^p(k-1)]-{\mathrm{\λ}}_2[{\mathrm{\φ}}_2^p\left(k\right)-{\mathrm{\φ}}_2^p(k-1)\left]\right\}$ Formula (17)

In actual computation process, assuming that epoch k and before epoch all repair without cycle slip or cycle slip, utilize the carrier phase observed quantity of two frequency bins to the ionosphere calculating each epoch total electron concentration rate of change TECR by formula (17).

Step6, according to TECR historical data prediction current epoch (k) TECR

Because ionosphere total electron content rate of change TECR can not acute variation at short notice.When sampling interval is 1s, before can utilizing current epoch (k), the data of 30s are averaged, using the TECR predicted value of this average as current epoch (k).

If but there is cycle slip in epoch (k), will there is relatively large deviation with predicted value data in the TECR (k) so calculated by formula (17), namely wherein can comprise cycle slip item impact.

Step7, utilize TECR historical data to calculate TECR method decision threshold to carry out Detection of Cycle-slip

Computation process and the 4th step of this step are similar, according to the ionosphere total electron content rate of change that first 30 calculate epoch, first obtain the mathematical expectation of TECR (k):

$E\left[\mathrm{TECR}\left(k\right)\right]=\stackrel{\‾}{\mathrm{TECR}\left(k\right)}=\stackrel{\‾}{\mathrm{TECR}(k-1)}+\frac{1}{30}[\mathrm{TECR}\left(k\right)-\stackrel{\‾}{\mathrm{TECR}(k-1)}]$ Formula (18)

Then, (TECR (k)) is calculated ²mathematical expectation:

$E\left[{\left(\mathrm{TECR}\left(k\right)\right)}^2\right]=E\left[{\left(\mathrm{TECR}(k-1)\right)}^2\right]+\frac{1}{30}\{{\left(\mathrm{TECR}\left(k\right)\right)}^2-E[{\left(\mathrm{TECR}(k-1)\right)}^2\left]\right\}$ Formula (19)

Utilize the standard variance of two formulae discovery TECR (k):

${\mathrm{\σ}}_{\mathrm{TECR}\left(k\right)}^2=E\left[{\left(\mathrm{TECR}\left(k\right)\right)}^2\right]-{\left(\stackrel{\‾}{\mathrm{TECR}\left(k\right)}\right)}^2$ Formula (20)

In judging process, using calculate 4 times of standard variances as the thresholding of Detection of Cycle-slip.If cycle slip judgement item is greater than thresholding, then illustrate to exist by cycle slip item the impact of introducing, think to there is cycle slip; If cycle slip judgement item is less than thresholding, then think without cycle slip.

TECR method can determine that MW method cannot determine situation, but for particular combination as (77N, 60N), N=± 1, ± 2 ... cycle slip cannot be determined.And now, the cycle slip on L1 and L2 at least differs 17 weeks, can be detected easily by MW combined method.Therefore, the cycle slip that ionosphere total electron content rate of change cannot be determined to detect MW method is utilized in this method.

Below by one group of embodiment, the invention will be further described:

In the detection method of the real time GPS carrier phase cycle slip of taming for frequency, the wide item blur level of MW is calculated by the formula (6) of step 2, the MW wide item blur level difference between adjacent epoch is carried out again, i.e. the cycle slip judgement item of MW method according to step 3.4 σ utilizing formula in step 4 (12) to obtain are as the thresholding of Detection of Cycle-slip.If MW cycle slip judgement item is greater than this thresholding, then think to there is cycle slip; If in threshold range, then need detect whether there is Δ N further by the subsequent step of TECR method ₁=Δ N ₂situation.TECR each epoch is calculated by formula in step 5 (17), comprise current epoch, before utilization, the data of 30 epoch on average carry out the TECR prediction of current epoch, the relatively difference of calculated value and predicted value, if exceed the decision threshold of 4 σ that step 7 formula (20) calculates, then think to there is cycle slip; Otherwise without cycle slip.

Comprehensively above-mentioned, the technical scheme that the present embodiment provides only according to current epoch and before the carrier phase of 30s and pseudo range observed quantity can detect the cycle slip that unit resolves generation completely, meet the requirement of real-time that frequency is tamed.

Obviously; the above embodiment of the present invention is only for example of the present invention is clearly described; and be not the restriction to embodiments of the present invention; for those of ordinary skill in the field; can also make other changes in different forms on the basis of the above description; here cannot give exhaustive to all embodiments, every belong to technical scheme of the present invention the apparent change of extending out or variation be still in the row of protection scope of the present invention.

Claims (8)

1. a detection method for the real time GPS carrier phase cycle slip of taming for frequency, it is characterized in that, the method comprises the steps:

S1, utilize observation equation, utilize the L1 frequency of GPS and the carrier phase observed quantity of L2 frequency and pseudo range observed quantity, calculate MW wide lane combination observation amount;

S2, according to MW wide lane combination estimation the wide lane of MW blur level;

S3, the MW of adjacent epoch wide lane ambiguity Difference Calculation cycle slip is utilized to adjudicate item [Δ N ₁(k)-Δ N ₂(k)];

S4, utilize wide lane ambiguity historical data to calculate cycle slip decision threshold, judge that cycle slip adjudicates item [Δ N ₁(k)-Δ N ₂(k)] whether exceed cycle slip decision threshold, to whether there is cycle slip epoch (k) detect, if it is process ends, if otherwise proceed to step S5;

S5, utilize GPS the observed quantity of L1 and L2 frequency carrier phase calculate epoch (k) ionosphere electron content rate of change TECR (k);

S6, the TECR value predicting epoch (k) according to TECR historical data;

S7, TECR historical data is utilized to calculate TECR method decision threshold, the calculated value of epoch (k) in step S5 and the predicted value of step S6 epoch (k) are asked difference, judge that whether difference is more than TECR method decision threshold, if it is think to there is cycle slip, if otherwise without cycle slip.

2. the detection method of real time GPS carrier phase cycle slip of taming for frequency according to claim 1, it is characterized in that, described step S1 comprises following sub-step further:

S1.1, by separate unit GPS dual-frequency receiver observation gps satellite p, calculate the carrier phase observed quantity of the L1 frequency of GPS respectively based on observation equation and pseudo range observed quantity the carrier phase observed quantity of L2 frequency and pseudo range observed quantity formula is as follows:

${\mathrm{\φ}}_1^p=\frac{{\mathrm{\ρ}}^p+c(d_t-d_{T^p})-I+T}{{\mathrm{\λ}}_1}+N_1^p$

${\mathrm{\φ}}_2^p=\frac{{\mathrm{\ρ}}^p+c(d_t-d_{T^p})-\mathrm{\γI}+T}{{\mathrm{\λ}}_2}+N_2^p$

$P_1^p={\mathrm{\ρ}}^p+c(d_t-d_{T^p})+I+T$

$P_2^p={\mathrm{\ρ}}^p+c(d_t-d_{T^p})+\mathrm{\γI}+T$

In formula, f ₁and f ₂be respectively the signal frequency of L1 and the L2 frequency of GPS, λ ₁and λ ₂be respectively the signal wavelength of L1 and the L2 frequency of GPS, ρ ^pfor the geometric distance between receiver and satellite p; d _tfor the clocking error of receiver; for the star clock error of satellite p; C is vacuum light speed; I is distance corresponding to the ionosphere time delay of the L1 frequency signal of GPS; T is distance corresponding to troposphere time delay; with the integer ambiguity of L1 and the L2 frequency of gps satellite p respectively; for GPS L1 and L2 signal frequency ratio square;

S1.2, the carrier phase observed quantity utilizing L1 and the L2 frequency of GPS each epoch and pseudo range observed quantity, calculate the MW wide lane combination observation amount L of GPS _mWWL, formula is as follows:

$L_{\mathrm{MWWL}}=\frac{f_1\·{\mathrm{\λ}}_1{\mathrm{\φ}}_1^p-f_2\·{\mathrm{\λ}}_2{\mathrm{\φ}}_2^p}{f_1-f_2}-\frac{f_1\·P_1^p+f_2\·P_2^p}{f_1+f_2}.$

3. the detection method of real time GPS carrier phase cycle slip of taming for frequency according to claim 2, is characterized in that, estimate that the formula of the blur level in the wide lane of MW is as follows in step S2:

$N_{\mathrm{WL}}^p=\frac{L_{\mathrm{MWWL}}}{{\mathrm{\λ}}_{\mathrm{WL}}}=[{\mathrm{\φ}}_1^p-{\mathrm{\φ}}_2^p-\frac{f_1\·P_1^p+f_2\·P_2^p}{{\mathrm{\λ}}_{\mathrm{WL}}(f_1+f_2)}]$

In formula, for wide lane ambiguity estimated value each epoch, λ _wL=c/ (f ₁-f ₂) ≈ 86cm, be wide lane wavelength.

4. the detection method of real time GPS carrier phase cycle slip of taming for frequency according to claim 3, is characterized in that, calculates cycle slip judgement item [Δ N in step S3 ₁(k)-Δ N ₂(k)] formula as follows:

$[\mathrm{\Δ}{N}_1^p\left(k\right)-\mathrm{\Δ}{N}_2^p\left(k\right)]=N_{\mathrm{WL}}^p\left(k\right)-N_{\mathrm{WL}}^p(k-1).$

5. the detection method of real time GPS carrier phase cycle slip of taming for frequency according to claim 4, it is characterized in that, in step S4, cycle slip decision threshold is the wide lane ambiguity estimated value of epoch (k) 4 times of standard variance.

6. the detection method of real time GPS carrier phase cycle slip of taming for frequency according to claim 1, it is characterized in that, described step S5 comprises following sub-step further:

S5.1, calculate the ionosphere total electron content of each epoch, formula is as follows:

$\mathrm{TEC}=\frac{{f_1}^2[({\mathrm{\λ}}_1{\mathrm{\φ}}_1^p-{\mathrm{\λ}}_2{\mathrm{\φ}}_2^p)-({\mathrm{\λ}}_1{N}_1-{\mathrm{\λ}}_2{N}_2)-b_i-b^p]}{40.3\×{10}^{16}(\mathrm{\γ}-1)}$

In formula, b _iand b ^pbe respectively two inter-frequency deviations of receiver and satellite, unit is m;

The total electron content rate of change of S5.2, calculating epoch (k), formula is as follows:

${\mathrm{TECR}}_{\mathrm{\φ}}\left(k\right)=\frac{{\mathrm{TEC}}_{\mathrm{\φ}}\left(k\right)-{\mathrm{TEC}}_{\mathrm{\φ}}(k-1)}{\mathrm{\Δt}}$

In formula, TECR _φk ionosphere total electron content rate of change that () is epoch (k); Δ t is epoch (k-1) and the time interval between epoch (k);

Ionosphere electron content rate of change TECR (k) of S5.3, calculating epoch (k), formula is as follows:

$\mathrm{TECR}\left(k\right)=\frac{{f_1}^2}{40.3\×{10}^{16}(\mathrm{\γ}-1)}\left\{{\mathrm{\λ}}_1\right[{\mathrm{\φ}}_1^p\left(k\right)-{\mathrm{\φ}}_1^p(k-1)]-{\mathrm{\λ}}_2[{\mathrm{\φ}}_2^p\left(k\right)-{\mathrm{\φ}}_2^p(k-1)\left]\right\}.$

7. the detection method of real time GPS carrier phase cycle slip of taming for frequency according to claim 6, it is characterized in that, predict in step S6 that the method for the TECR value of current epoch (k) is for setting sampling interval as 1s, before utilizing epoch (k), the data of 30s are averaged, using the TECR predicted value of this average as current epoch k.

8. the detection method of real time GPS carrier phase cycle slip of taming for frequency according to claim 6, it is characterized in that, in step S7, TECR method decision threshold is 4 times of the standard variance in ionosphere electron content rate of change TECR (k) of epoch (k).