CN103901440A - GNSS data signal quality monitor method - Google Patents

Abstract

The invention provides a GNSS data signal quality monitor method. The GNSS data signal quality monitor method includes the steps that every observation station receives original satellite data and transmits the original satellite data to a data processing center via a communication network; the data processing center calculates the satellite clock error of n satellite clocks and other (m-1) receiver clocks relative to a reference receiver clock; the maximum error point of a satellite is calculated within the visible range of the satellite; the signal error of the maximum error point position is analyzed according to the satellite clock error, and then the GNSS data signal quality is monitored. According to the GNSS data signal quality monitor method, when the GNSS data signal quality is monitored, the satellite clock error accuracy, space signal forecast accuracy and space data signal quality monitor accuracy are monitored in real time, and as the accuracy is compared with a threshold value and is monitored and issued in real time, the GNSS data signal quality can be monitored in real time.

Description

The monitoring method of GNSS data signal quality

Technical field

The invention belongs to Satellite Navigation Technique field, be specifically related to a kind of monitoring method of GNSS data signal quality.

Background technology

GNSS(Global Navigation Satellite System, GLONASS (Global Navigation Satellite System)) be widely used at present military field and civil area, because it has accurately, in real time, is not subject to the features such as regional limits, become navigational tool general in land traffic, navigation and aviation.

The precise evaluation of GNSS data and signal quality, is not only the accurately prerequisite of judgement of entire system precision, also there is to very important effect system failure location and system optimization.The monitoring of GNSS signal quality can be divided into physical signalling quality monitoring and data signal quality monitoring.Wherein physical signalling quality monitoring refers to for original GNSS signal and carries out signal quality analysis; And data signal quality monitoring refers to for GNSS observation data and carries out the analysis of GNSS signal quality.

Aspect physical signalling quality monitoring, in October, 1993 GPS of America-SV19 satellite generation abnormal signal, cause the pseudorange error of 3m～8m, from 1997, research institution of Stanford University (SRI) adds GPS of America co-plan, be responsible for monitoring gps satellite L-band signal, fundamental purpose is the work reliably continuously of all satellites of assurance system, ensures security, the completeness of user job.。The researchist of Stanford University utilizes 47m large aperture antenna system and 3m antenna system, signal power, code time delay, frequency and the satellite constellation rationality of long term monitoring GPS, and carried out data acquisition and Performance Evaluation work.Europe GALILEO has completed Giove-A and Giove-B transmitting and satellite test assignment in-orbit.The spacing wave test assignment of GALILEO is mainly completed by the navigation laboratory in European space technology research centre (ESTEC), and set up surface-based observing station in multiple places, and as: Qi Er Bowden astronomical observatory of Britain (Chilboiton), German aerospace research institute (DLR), European Space Agency (ESA) etc.Qi Er Bowden astronomical observatory utilizes 25m antenna system settling signal power measurement and checking, signal modulating characteristic, the monitoring of signal band stray, utilizes experiment test receiver settling signal to follow the tracks of and navigation information assessment.Aerospace research institute of Germany (DLR) utilizes 30m antenna settling signal to gather and Off-line data analysis work.National Time Service Center, Chinese Academy of Sciences (NTSC) has set up a set of GNSS spacing wave quality monitoring and evaluating system in April, 2009.This system comprises 7.3m antenna, radio system, reference instrument system, data acquisition system (DAS), receiver and off line data analysis system.System can receive L-band signal, instrument system both can realize the Real-Time Monitoring such as ground received power (band internal power), frequency (frequency spectrum, bandwidth etc.) to navigation signal, also can carry out Real-Time Monitoring as power spectrum density, eye pattern, planisphere, signal modulation parameter etc. to representative communication signal parameter.Utilize receiver to realize the monitoring of receiver observed parameter, system possesses high-speed data acquistion system simultaneously, has realized data acquisition real-time storage and off-line analysis.

Aspect data signal quality monitoring, Wang Fuhong has studied spaceborne GPS pseudo range measurement accuracy assessment method, draws: elevation of satellite is larger, and the precision of pseudo range measurement is higher; Between rough error and elevation of satellite, do not have obvious relation; If low orbit satellite will utilize constellation GPS, pseudo range measurement is successfully realized autonomous orbit determination, must fully understand the measured precision of Pseudo-range Observations, the conclusion of the detecting and elimination method of research pseudorange rough error.Hu great Wei sets about from Analysis signal-to-noise ratio (SNR), multipath analysis, three aspects of residual analysis, the quality of data of Galileo experiment star GIOVE-A is analyzed, and compared with GPSCA code.Dai Wujiao thinks that elevation of satellite, carrier-to-noise ratio and signal intensity are the important indicators of reflection GPS observed reading quality, and the probabilistic model based on these indexs can further weaken the impact of the remaining atmosphere delay of GPS, diffraction and multipath effect equal error.Tian Zehai collateral security GPS monitoring network meets the requirement of monitoring accuracy sets out, and has proposed the collection of GPS field data, baseline is settled accounts measure and the data processing method that should take.Li Yinsheng is by the data analysis of two RTK practical measuring examples, RTK is discussed and has measured the problem such as measuring accuracy and achievement reliability that can reach, and to the suitable base station of How to choose, how to solve accurately coordinate transformation parameter, how according to the concrete mission requirements of measuring, carry out the design of RTK measuring technique, thereby further improve the quality of data, proposed correlation technique measure.

But for above-mentioned GNSS data signal quality monitoring, still there is defective data quality in the accuracy of its Monitoring Data and completeness, is difficult to GNSS data signal quality to carry out effective, accurate and real-time monitoring.

Summary of the invention

For the defect of prior art existence, the invention provides a kind of monitoring method of GNSS data signal quality, can carry out effective, accurate and real-time monitoring to GNSS data signal quality.

The technical solution used in the present invention is as follows:

The monitoring method that the invention provides a kind of GNSS data signal quality, comprises the following steps:

Step 101, each research station of GNSS CORS system receives respectively satellite raw data; Wherein, described satellite raw data comprises satellite ephemeris and satellite original observed data;

Step 102, each research station arrives data processing centre (DPC) by communication network by described satellite original data transmissions;

Step 103, described data processing centre (DPC) carries out analyzing and processing to the described satellite raw data receiving, be specially: establish total m research station and synchronously follow the tracks of n satellite, in m research station, the receiver clock of choosing on a certain research station that precision meets the demands is reference receiver clock, calculates respectively n satellite clock and other m-1 the receiver clocks satellite clock correction with respect to reference receiver clock;

Step 104 is calculated the maximum error point of satellite in satellite visible range;

Step 105, in conjunction with described satellite clock correction, analyzes the signal errors of maximum error point position, and then monitoring GNSS data signal quality.

Preferably, described satellite ephemeris is used for calculating each coordinate of the satellite position; Described satellite original observed data comprises Pseudo-range Observations, essence code observed reading and carrier phase observation data.

Preferably, the precision of described reference receiver clock reaches 10 ^-6second.

Preferably, in step 103, calculate satellite clock correction by the error equation of relative satellite clock correction;

If take the receiver clock of first research station as reference receiver clock, the observed reading error equation on first research station is:

$v_1^j\left(i\right)=-({\mathrm{\Δt}}^j\left(i\right)-{\mathrm{\Δt}}_1\left(i\right))+l_1^j\left(i\right)=-\mathrm{\Δ}{\stackrel{\‾}{t}}^j\left(i\right)+l_1^j\left(i\right)---\left(1\right)$

Observed reading error equation on other m-1 research station is:

$\begin{array}{c}{v}_k^j\left(i\right)={\mathrm{\Δt}}_k-{\mathrm{\Δt}}^j\left(i\right)+l_k^j\left(i\right)\\ =({\mathrm{\Δt}}_k\left(i\right)-{\mathrm{\Δt}}_1\left(i\right))-({\mathrm{\Δt}}^j\left(i\right)-{\mathrm{\Δt}}_1\left(i\right))+l_k^j\left(i\right)\\ =\mathrm{\Δ}{\stackrel{\‾}{t}}_k\left(i\right)-\mathrm{\Δ}{\stackrel{\‾}{t}}^j\left(i\right)+l_k^j\left(i\right)\end{array}---\left(2\right)$

: the error equation of satellite clock correction is expressed as relatively:

V(i)＝AX(i)+L(i) （3）

Wherein:

$\underset{m\×n,m+n-1}{A}=\left[\begin{array}{cc}0& -I\\ e_1& -I\\ \·\·\·& \·\·\·\\ e_{m-1}& -I\end{array}\right]---\left(4\right)$

$\underset{n,m-1}{e_i}=\left[\begin{array}{ccccc}0& \·\·\·& 1& \·\·\·& 0\\ 0& \·\·\·& 1& \·\·\·& 0\\ \·\·\·& \·\·\·& \·\·\·& \·\·\·& 0\\ 0& \·\·\·& 1& \·\·\·& 0\\ & & i-1& & \end{array}\right],i\≠1--\left(5\right)$

$\underset{(m+n-1)\×1}{X\left(i\right)}={\left[\begin{array}{c}\mathrm{\Δ}{\stackrel{\‾}{t}}_2,{\mathrm{\Δ}\stackrel{\‾}{t}}_3,...,\mathrm{\Δ}{\stackrel{\‾}{t}}_m,\mathrm{\Δ}{t}^{-1},\mathrm{\Δ}{t}^{-2},...,\mathrm{\Δ}{\stackrel{\‾}{t}}^n\end{array}\right]}^T---\left(6\right)$

$\underset{m\×n,l}{L}={\left[\begin{array}{c}{l}_1^1,...,l_1^n,l_2^1,...,l_2^n,...,l_m^1,...,l_m^n\end{array}\right]}^T---\left(7\right)$

In formula: A is the design matrix while determining receiver and satellite clock correction, is (m × n) (m+n-1) rank matrix; V _k ^j(i) be observational error; X (i) is unknown number, comprises satellite clock correction and base station receiver clock correction; L (i) is constant term; I is n rank unit matrixs, unknown number Δ t ₁, Δ t _k, Δ t ^j,

be respectively reference receiver clock correction, a k receiver clock correction, a j satellite clock clock correction, with respect to the relative receiver clock correction of Reference clock with respect to the satellite clock correction of Reference clock, constant term

it is the value of i epoch.

Preferably, in step 104, described maximum error point refers to the worst impact position that signal in space error causes in the visible range of satellite, extends or advancing the track error vector in the other direction, and the intersection point of itself and earth surface is maximum error point.

Preferably, step 105 specifically comprises following two kinds of methods:

Method one: calculate the GNSS data-signal error of maximum error point position, and then calculate the spacing wave forecast precision of satellite, by this spacing wave forecast precision and setting threshold comparison, monitoring GNSS data signal quality;

Method two: calculate GNSS data signal quality monitoring accuracy according to the unit vector of error equation coefficient and maximum error point, by this data signal quality monitoring accuracy and setting threshold comparison, whether normally monitor current satellitosis.

Preferably, method one is specially: supposition maximum error point place signal errors is obeyed the normal distribution of standard, the signal quality forecast precision standard deviation of normal distribution for this reason, the i.e. lowest standard deviation of maximum error point place signal errors; By signal quality forecast precision and setting threshold comparison, monitor satellite signal quality, judges that whether current satellite data state is normal.

Preferably, method two is specially:

When carry out satellite clock correction and orbit error calculating based on base station, its error equation is expressed as:

${\mathrm{\Δ\ρ}}^j=\left[\begin{array}{c}{\mathrm{\Δ\ρ}}_1^j\\ {\mathrm{\Δ\ρ}}_2^j\\ \·\\ \·\\ \·\\ {\mathrm{\Δ\ρ}}_i^j\end{array}\right]=\left[\begin{array}{cccc}{e}_{1x}^j& e_{1y}^j& e_{1z}^j& 1\\ e_{2x}^j& e_{2y}^j& e_{2z}^j& 1\\ \·& \·& \·& \·\\ \·& \·& \·& \·\\ \·& \·& \·& \·\\ e_{\mathrm{ix}}^j& e_{\mathrm{iy}}^j& e_{\mathrm{iz}}^j& 1\end{array}\right]\left[\begin{array}{c}{\mathrm{\Δx}}_s\\ {\mathrm{\Δy}}_s\\ {\mathrm{\Δz}}_s\\ {\mathrm{c\Δt}}_s\end{array}\right]+\left[\begin{array}{c}{b}_1^j\\ b_2^j\\ \·\\ \·\\ \·\\ b_i^j\end{array}\right]---\left(8\right)$

Wherein: $H=\left[\begin{array}{cccc}{e}_{1x}^j& e_{1y}^j& e_{1z}^j& 1\\ e_{2x}^j& e_{2y}^j& e_{2z}^j& 1\\ \·& \·& \·& \·\\ \·& \·& \·& \·\\ \·& \·& \·& \·\\ e_{\mathrm{ix}}^j& e_{\mathrm{iy}}^j& e_{\mathrm{iz}}^j& 1\end{array}\right]$ The matrix that the unit vector that formed by j satellite and base station forms, $B_S={\left[\begin{array}{cccc}{b}_1^j& b_2^j& \·\·\·& b_i^j\end{array}\right]}^T$ It is receiver noise;

:

Suppose $a^j=\left[\begin{array}{cccc}{e}_x^j& e_y^j& e_z^j& 1\end{array}\right]$ Be the vector that satellite j and maximum error point line form, can obtain GNSS data signal quality monitoring accuracy:

$\mathrm{DSQM}=\sqrt{a_{\mathrm{wul}}{\left(H^T{\left(\mathrm{cov}\left(B_s\right)\right)}^{-1}H\right)}^{-1}{a}_{\mathrm{wul}}^T}---\left(10\right)$

By DSQM value and setting threshold comparison, signal quality is carried out to Real-Time Monitoring, judge that whether current satellite data state is normal.

Beneficial effect of the present invention is as follows:

The monitoring method of GNSS data signal quality provided by the invention, in the time carrying out the monitoring of GNSS data signal quality, satellite clock correction precision, spacing wave forecast precision and spatial data signal quality monitoring accuracy are carried out to Real-Time Monitoring, by monitoring more in real time and issue with its threshold value, realize the Real-Time Monitoring of GNSS data signal quality.

Accompanying drawing explanation

Fig. 1 is the monitoring method schematic flow sheet of GNSS data signal quality provided by the invention.

Embodiment

For making the object, technical solutions and advantages of the present invention clearer, below in conjunction with accompanying drawing, the present invention is described in further detail.

As shown in Figure 1, the monitoring method of GNSS data signal quality provided by the invention, comprises the following steps:

Each research station of step 101, GNSS CORS system receives respectively satellite raw data; Wherein, described satellite raw data comprises satellite ephemeris and satellite original observed data; Described research station is CORS station, and receiver is set on it;

GNSS CORS(Continuous Operational Reference System, is abbreviated as CORS) system be utilize many base station networks technology set up continuous operation satnav service colligate system.CORS station is distributed in the working range of the network coverage, and independently GNSS website of each CORS station conduct, receives corresponding satellite ephemeris and original observed data separately.Satellite ephemeris is broadcast once for every two hours, can be for calculating coordinate of the satellite position.And original observed data generally comprises Pseudo-range Observations, essence code observed reading and carrier phase observation data etc., it is the basic data of carrying out data processing.In the present invention, using satellite ephemeris and satellite original observed data all as the raw data of GNSS location.

Step 102, each research station arrive data processing centre (DPC) by communication network by described satellite original data transmissions;

Concrete, each research station receives after satellite raw data separately, satellite raw data is real-time transmitted to master station according to the sampling rate packing of 1 second, data layout can adopt RINEX form (Receiver Independent Exchange Format, with the irrelevant Interchange Format of receiver) or the user-defined format of standard.

Step 103, establish total m research station and synchronously follow the tracks of n satellite, in m research station, the receiver clock of choosing on a certain research station that precision meets the demands is reference receiver clock, calculates respectively n satellite clock and other m-1 the receiver clocks satellite clock correction with respect to reference receiver clock;

Concrete, choosing receiver clock when with reference to clock, need guarantee that the precision of this receiver clock is better than 10 ^-6second.But because receiver clock is generally crystal clock, still can not meet this accuracy requirement, therefore need reference receiver clock to take the mode of single-point location to carry out according to a preliminary estimate the clock correction of receiver clock, guarantee that the precision of reference receiver clock meets 10 ^-6the requirement of second.

If take the receiver clock of first research station as reference receiver clock, the observed reading error equation on first research station is:

$v_1^j\left(i\right)=-({\mathrm{\Δt}}^j\left(i\right)-{\mathrm{\Δt}}_1\left(i\right))+l_1^j\left(i\right)=-\mathrm{\Δ}{\stackrel{\‾}{t}}^j\left(i\right)+l_1^j\left(i\right)---\left(1\right)$

Observed reading error equation on other m-1 research station is:

$\begin{array}{c}{v}_k^j\left(i\right)={\mathrm{\Δt}}_k-{\mathrm{\Δt}}^j\left(i\right)+l_k^j\left(i\right)\\ =({\mathrm{\Δt}}_k\left(i\right)-{\mathrm{\Δt}}_1\left(i\right))-({\mathrm{\Δt}}^j\left(i\right)-{\mathrm{\Δt}}_1\left(i\right))+l_k^j\left(i\right)\\ =\mathrm{\Δ}{\stackrel{\‾}{t}}_k\left(i\right)-\mathrm{\Δ}{\stackrel{\‾}{t}}^j\left(i\right)+l_k^j\left(i\right)\end{array}---\left(2\right)$

: the error equation of satellite clock correction is expressed as relatively:

V(i)＝AX(i)+L(i) （3）

Wherein:

$\underset{m\×n,m+n-1}{A}=\left[\begin{array}{cc}0& -I\\ e_1& -I\\ \·\·\·& \·\·\·\\ e_{m-1}& -I\end{array}\right]---\left(4\right)$

$\underset{n,m-1}{e_i}=\left[\begin{array}{ccccc}0& \·\·\·& 1& \·\·\·& 0\\ 0& \·\·\·& 1& \·\·\·& 0\\ \·\·\·& \·\·\·& \·\·\·& \·\·\·& 0\\ 0& \·\·\·& 1& \·\·\·& 0\\ & & i-1& & \end{array}\right]i\≠1--\left(5\right)$

$\underset{(m+n-1)\×1}{X\left(i\right)}={\left[\begin{array}{c}\mathrm{\Δ}{\stackrel{\‾}{t}}_2,{\mathrm{\Δ}\stackrel{\‾}{t}}_3,...,\mathrm{\Δ}{\stackrel{\‾}{t}}_m,\mathrm{\Δ}{t}^{-1},\mathrm{\Δ}{t}^{-2},...,\mathrm{\Δ}{\stackrel{\‾}{t}}^n\end{array}\right]}^T---\left(6\right)$

$\underset{m\×n,l}{L}={\left[\begin{array}{c}{l}_1^1,...,l_1^n,l_2^1,...,l_2^n,...,l_m^1,...,l_m^n\end{array}\right]}^T---\left(7\right)$

In formula: A is the design matrix while determining receiver and satellite clock correction, is (m × n) (m+n-1) rank matrix; V _k ^j(i) be observational error; X (i) is unknown number, comprises satellite clock correction and base station receiver clock correction; L (i) is constant term; I is n rank unit matrixs, unknown number Δ t ₁, Δ t _k, Δ t ^j,

be respectively reference receiver clock correction, a k receiver clock correction, a j satellite clock clock correction, with respect to the relative receiver clock correction of Reference clock with respect to the satellite clock correction of Reference clock, constant term

it is the value of i epoch.This shows, the error equation of satellite clock correction normal equation is now nonsingular relatively, and the estimation of parameter can adopt corresponding estimation criterion to estimate.Satellite clock correction precision and its threshold value are compared, judge that whether current satellite data state is normal.

Step 104, in satellite visible range, calculate the maximum error point of satellite.

Maximum error point refers to the worst impact position that signal in space error causes in the visible range of satellite.Because satellite clock correction produces identical impact to all users in satellite viewing area, the impact that satellite orbital error produces is different and different with customer location.Therefore, maximum error point (WUL) mainly depends on satellite orbital error.The definition of being put from maximum error, calculating maximum error point is exactly to find the user position with maximum distance error.Known according to the propagation law of error, in the time extending (or extending) orbit error vector in the other direction, should there is maximum distance error with the intersection point of earth surface, be maximum error point.

Maximum error point is a concept in three dimensions, in order to be processed into two-dimensional problems, might as well suppose that the earth is a spheroid, calculates the position of maximum error point on the surface of the earth.Be under the condition of a spheroid at the supposition earth, known, the earth's core, satellite and orbit error have formed a plane, and this plane is cut a cross section that the earth forms and formed a great circle of ground ball.From above-mentioned analysis, suppose the surface of user at the earth, in the great circle that maximum error point should form at above-mentioned plane and the earth, like this maximum error point is asked and determined problem and become two dimension by three-dimensional.Under above-mentioned hypothesis, utilize the position relationship of character and sub-satellite point etc. the point of spheroid, determine the coordinate of maximum error point on spheroid, and then utilize the relation between ellipsoid and ball, obtain the position of maximum error point on ellipsoid.

The GNSS data-signal error of step 105-a, calculating maximum error point position, and then the spacing wave forecast precision of calculating satellite, by this spacing wave forecast precision and setting threshold comparison, monitoring GNSS data signal quality.

Concrete, under standard state, the variation at maximum error point place signal errors of satellite within a period of time is more stable, change less, without real-time prediction, can think that maximum error point place signal errors meets normal distribution, can adopt statistical theory, estimate in a period of time, under certain confidence level, effectively define the minimum coboundary of maximum error point place signal errors.Suppose the normal distribution of maximum error point place signal errors obedience standard, the signal quality forecast precision standard deviation of normal distribution for this reason, the i.e. lowest standard deviation of maximum error point place signal errors.This value and its threshold value are compared, and monitor satellite signal quality, judges that whether current satellite data state is normal.

Step 105-b, calculate GNSS data signal quality monitoring accuracy according to the unit vector of error equation coefficient and maximum error point, by this data signal quality monitoring accuracy and setting threshold comparison, whether normally monitor current satellitosis.

Concrete, when carry out satellite clock correction and orbit error calculating based on base station, its error equation can be expressed as:

${\mathrm{\Δ\ρ}}^j=\left[\begin{array}{c}{\mathrm{\Δ\ρ}}_1^j\\ {\mathrm{\Δ\ρ}}_2^j\\ \·\\ \·\\ \·\\ {\mathrm{\Δ\ρ}}_i^j\end{array}\right]=\left[\begin{array}{cccc}{e}_{1x}^j& e_{1y}^j& e_{1z}^j& 1\\ e_{2x}^j& e_{2y}^j& e_{2z}^j& 1\\ \·& \·& \·& \·\\ \·& \·& \·& \·\\ \·& \·& \·& \·\\ e_{\mathrm{ix}}^j& e_{\mathrm{iy}}^j& e_{\mathrm{iz}}^j& 1\end{array}\right]\left[\begin{array}{c}{\mathrm{\Δx}}_s\\ {\mathrm{\Δy}}_s\\ {\mathrm{\Δz}}_s\\ {\mathrm{c\Δt}}_s\end{array}\right]+\left[\begin{array}{c}{b}_1^j\\ b_2^j\\ \·\\ \·\\ \·\\ b_i^j\end{array}\right]---\left(8\right)$

Wherein:

$H=\left[\begin{array}{cccc}{e}_{1x}^j& e_{1y}^j& e_{1z}^j& 1\\ e_{2x}^j& e_{2y}^j& e_{2z}^j& 1\\ \·& \·& \·& \·\\ \·& \·& \·& \·\\ \·& \·& \·& \·\\ e_{\mathrm{ix}}^j& e_{\mathrm{iy}}^j& e_{\mathrm{iz}}^j& 1\end{array}\right]$ The matrix that the unit vector that formed by j satellite and base station forms, $B_S={\left[\begin{array}{cccc}{b}_1^j& b_2^j& \·\·\·& b_i^j\end{array}\right]}^T$ It is receiver noise;

:

Suppose $a^j=\left[\begin{array}{cccc}{e}_x^j& e_y^j& e_z^j& 1\end{array}\right]$ Be the vector that satellite j and maximum error point line form, can obtain GNSS data signal quality monitoring accuracy:

$\mathrm{DSQM}=\sqrt{a_{\mathrm{wul}}{\left(H^T{\left(\mathrm{cov}\left(B_s\right)\right)}^{-1}H\right)}^{-1}{a}_{\mathrm{wul}}^T}---\left(10\right)$

DSQM value and its threshold value are compared, signal quality is carried out to Real-Time Monitoring, judge that whether current satellite data state is normal.

In sum, the monitoring method of GNSS data signal quality provided by the invention, in the time carrying out the monitoring of GNSS data signal quality, satellite clock correction precision, spacing wave forecast precision and spatial data signal quality monitoring accuracy are carried out to Real-Time Monitoring, by monitoring more in real time and issue with its threshold value, realize the Real-Time Monitoring of GNSS data signal quality.

The above is only the preferred embodiment of the present invention; it should be pointed out that for those skilled in the art, under the premise without departing from the principles of the invention; can also make some improvements and modifications, these improvements and modifications also should be looked protection scope of the present invention.

Claims (8)

1. a monitoring method for GNSS data signal quality, is characterized in that, comprises the following steps:

Step 101, each research station of GNSS CORS system receives respectively satellite raw data; Wherein, described satellite raw data comprises satellite ephemeris and satellite original observed data;

Step 102, each research station arrives data processing centre (DPC) by communication network by described satellite original data transmissions;

Step 103, described data processing centre (DPC) carries out analyzing and processing to the described satellite raw data receiving, be specially: establish total m research station and synchronously follow the tracks of n satellite, in m research station, the receiver clock of choosing on a certain research station that precision meets the demands is reference receiver clock, calculates respectively n satellite clock and other m-1 the receiver clocks satellite clock correction with respect to reference receiver clock;

Step 104 is calculated the maximum error point of satellite in satellite visible range;

Step 105, in conjunction with described satellite clock correction, analyzes the signal errors of maximum error point position, and then monitoring GNSS data signal quality.

2. the monitoring method of GNSS data signal quality according to claim 1, is characterized in that, described satellite ephemeris is used for calculating each coordinate of the satellite position; Described satellite original observed data comprises Pseudo-range Observations, essence code observed reading and carrier phase observation data.

3. the monitoring method of GNSS data signal quality according to claim 1, is characterized in that, the precision of described reference receiver clock reaches 10 ^-6second.

4. the monitoring method of GNSS data signal quality according to claim 1, is characterized in that, in step 103, calculates satellite clock correction by the error equation of relative satellite clock correction;

If take the receiver clock of first research station as reference receiver clock, the observed reading error equation on first research station is:

$v_1^j\left(i\right)=-({\mathrm{\Δt}}^j\left(i\right)-{\mathrm{\Δt}}_1\left(i\right))+l_1^j\left(i\right)=-\mathrm{\Δ}{\stackrel{\‾}{t}}^j\left(i\right)+l_1^j\left(i\right)---\left(1\right)$

Observed reading error equation on other m-1 research station is:

$\begin{array}{c}{v}_k^j\left(i\right)={\mathrm{\Δt}}_k-{\mathrm{\Δt}}^j\left(i\right)+l_k^j\left(i\right)\\ =({\mathrm{\Δt}}_k\left(i\right)-{\mathrm{\Δt}}_1\left(i\right))-({\mathrm{\Δt}}^j\left(i\right)-{\mathrm{\Δt}}_1\left(i\right))+l_k^j\left(i\right)\\ =\mathrm{\Δ}{\stackrel{\‾}{t}}_k\left(i\right)-\mathrm{\Δ}{\stackrel{\‾}{t}}^j\left(i\right)+l_k^j\left(i\right)\end{array}---\left(2\right)$

: the error equation of satellite clock correction is expressed as relatively:

V(i)＝AX(i)+L(i) （3）

Wherein:

$\underset{m\×n,m+n-1}{A}=\left[\begin{array}{cc}0& -I\\ e_1& -I\\ \·\·\·& \·\·\·\\ e_{m-1}& -I\end{array}\right]---\left(4\right)$

$\underset{n,m-1}{e_i}=\left[\begin{array}{ccccc}0& \·\·\·& 1& \·\·\·& 0\\ 0& \·\·\·& 1& \·\·\·& 0\\ \·\·\·& \·\·\·& \·\·\·& \·\·\·& 0\\ 0& \·\·\·& 1& \·\·\·& 0\\ & & i-1& & \end{array}\right]i\≠1--\left(5\right)$

$\underset{(m+n-1)\×1}{X\left(i\right)}={\left[\begin{array}{c}\mathrm{\Δ}{\stackrel{\‾}{t}}_2,{\mathrm{\Δ}\stackrel{\‾}{t}}_3,...,\mathrm{\Δ}{\stackrel{\‾}{t}}_m,\mathrm{\Δ}{t}^{-1},\mathrm{\Δ}{t}^{-2},...,\mathrm{\Δ}{\stackrel{\‾}{t}}^n\end{array}\right]}^T---\left(6\right)$

$\underset{m\×n,l}{L}={\left[\begin{array}{c}{l}_1^1,...,l_1^n,l_2^1,...,l_2^n,...,l_m^1,...,l_m^n\end{array}\right]}^T---\left(7\right)$

In formula: A is the design matrix while determining receiver and satellite clock correction, is (m × n) (m+n-1) rank matrix; V _k ^j(i) be observational error; X (i) is unknown number, comprises satellite clock correction and base station receiver clock correction; L (i) is constant term; I is n rank unit matrixs, unknown number Δ t ₁, Δ t _k, Δ t ^j,

be respectively reference receiver clock correction, a k receiver clock correction, a j satellite clock clock correction, with respect to the relative receiver clock correction of Reference clock with respect to the satellite clock correction of Reference clock, constant term

it is the value of i epoch.

5. the monitoring method of GNSS data signal quality according to claim 1, it is characterized in that, in step 104, described maximum error point refers to the worst impact position that signal in space error causes in the visible range of satellite, extend or advancing the track error vector in the other direction, the intersection point of itself and earth surface is maximum error point.

6. the monitoring method of GNSS data signal quality according to claim 1, is characterized in that, step 105 specifically comprises following two kinds of methods:

Method one: calculate the GNSS data-signal error of maximum error point position, and then calculate the spacing wave forecast precision of satellite, by this spacing wave forecast precision and setting threshold comparison, monitoring GNSS data signal quality;

Method two: calculate GNSS data signal quality monitoring accuracy according to the unit vector of error equation coefficient and maximum error point, by this data signal quality monitoring accuracy and setting threshold comparison, whether normally monitor current satellitosis.

7. the monitoring method of GNSS data signal quality according to claim 6, it is characterized in that, method one is specially: supposition maximum error point place signal errors is obeyed the normal distribution of standard, the signal quality forecast precision standard deviation of normal distribution for this reason, the i.e. lowest standard deviation of maximum error point place signal errors; By signal quality forecast precision and setting threshold comparison, monitor satellite signal quality, judges that whether current satellite data state is normal.

8. the monitoring method of GNSS data signal quality according to claim 6, is characterized in that, method two is specially:

When carry out satellite clock correction and orbit error calculating based on base station, its error equation is expressed as:

${\mathrm{\Δ\ρ}}^j=\left[\begin{array}{c}{\mathrm{\Δ\ρ}}_1^j\\ {\mathrm{\Δ\ρ}}_2^j\\ \·\\ \·\\ \·\\ {\mathrm{\Δ\ρ}}_i^j\end{array}\right]=\left[\begin{array}{cccc}{e}_{1x}^j& e_{1y}^j& e_{1z}^j& 1\\ e_{2x}^j& e_{2y}^j& e_{2z}^j& 1\\ \·& \·& \·& \·\\ \·& \·& \·& \·\\ \·& \·& \·& \·\\ e_{\mathrm{ix}}^j& e_{\mathrm{iy}}^j& e_{\mathrm{iz}}^j& 1\end{array}\right]\left[\begin{array}{c}{\mathrm{\Δx}}_s\\ {\mathrm{\Δy}}_s\\ {\mathrm{\Δz}}_s\\ {\mathrm{c\Δt}}_s\end{array}\right]+\left[\begin{array}{c}{b}_1^j\\ b_2^j\\ \·\\ \·\\ \·\\ b_i^j\end{array}\right]---\left(8\right)$

Wherein: $H=\left[\begin{array}{cccc}{e}_{1x}^j& e_{1y}^j& e_{1z}^j& 1\\ e_{2x}^j& e_{2y}^j& e_{2z}^j& 1\\ \·& \·& \·& \·\\ \·& \·& \·& \·\\ \·& \·& \·& \·\\ e_{\mathrm{ix}}^j& e_{\mathrm{iy}}^j& e_{\mathrm{iz}}^j& 1\end{array}\right]$ The matrix that the unit vector that formed by j satellite and base station forms, $B_S={\left[\begin{array}{cccc}{b}_1^j& b_2^j& \·\·\·& b_i^j\end{array}\right]}^T$ It is receiver noise;

:

Suppose $a^j=\left[\begin{array}{cccc}{e}_x^j& e_y^j& e_z^j& 1\end{array}\right]$ Be the vector that satellite j and maximum error point line form, can obtain GNSS data signal quality monitoring accuracy:

$\mathrm{DSQM}=\sqrt{a_{\mathrm{wul}}{\left(H^T{\left(\mathrm{cov}\left(B_s\right)\right)}^{-1}H\right)}^{-1}{a}_{\mathrm{wul}}^T}---\left(10\right)$

By DSQM value and setting threshold comparison, signal quality is carried out to Real-Time Monitoring, judge that whether current satellite data state is normal.

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