CN106842256B - A kind of navigation locating method using the mono- star signal of GNSS - Google Patents

Abstract

The present invention is a navigation and positioning method using GNSS single-satellite signals. First, select a clock with a frequency stability better than a certain index for data collection, and obtain the position and pseudorange of a single GNSS navigation satellite at different times; secondly, downsample the data, and select MEO satellites or IGSO satellites for navigation position calculation. Finally, the position of the receiver is calculated by iterative solution and the positioning result is output. The invention overcomes the disadvantage that the GNSS navigation and positioning method cannot be used when there are less than four observation satellites, and realizes the high-precision navigation and positioning of only observing a single GNSS signal. The method of the invention needs to observe a small number of GNSS satellites and has high positioning accuracy, which can solve the problem of self-navigation and positioning when the lunar receiver only measures one GNSS satellite signal. Navigation positioning.

Description

A kind of navigation locating method using the mono- star signal of GNSS

Technical field

The invention belongs to technical field of satellite navigation, are related to a kind of navigation locating method using the mono- star signal of GNSS.

Background technique

In " development of moon navigation signal receiver engineering prototype " project task, lunar orbiter is needed in moonscape Its own position is positioned, however the moon away from the earth farther out, moon receiver can not effectively capture GNSS signal And tracking, therefore the navigator fix to its own can not be realized by reception four or more GNSS navigation satellite signals.The moon connects The navigator fix of receipts machine itself is one of urgent problem to be solved in moon exploration program." being based on XX single star navigation location technology " In 863 project tasks, for the mission requirements of emergency response single star navigation positioning, it is fixed to need to study the navigation based on the measurement of single star Position key technology studies principle prototype and carries out ground validation test.When GNSS system receives interference or failure, using single star It carries out emergency navigation and realizes self poisoning, there is stronger military demand and researching value.In addition, when GNSS receiver on ground It positioned at multipaths such as city, mountain area, mountain valley, valley, thick forests, blocks in environment, since four or more cannot be received simultaneously more GNSS satellite signal, so as to cause the failure of its positioning function.Therefore, need research multipath, block more under environment receive be less than The navigation locating method of receiver itself when four observation GNSS satellite signals, get off in the hidden environment such as thick forest itself The navigator fix etc. of personnel is of great significance and is worth under positioning, mountain area environment.

Summary of the invention

Technical problem solved by the present invention is overcoming the deficiencies of the prior art and provide a kind of using the mono- star signal of GNSS Navigation locating method solves GNSS receiver when only receiving single GNSS satellite signal, asks the navigator fix of its own Topic.

The technical solution of this method is: a kind of navigation locating method using the mono- star signal of GNSS, comprising the following steps:

1) selection frequency stability carries out data acquisition better than the clock of pre-set level, obtains single GNSS of different moments and leads The position of boat satellite and pseudorange；Enable Ω_x,y,zAnd Ω_ρRespectively t₁To t_NThe coordinate set of GNSS navigation satellite can be observed in moment Conjunction and pseudorange set, record t by formula (1) and formula (2) respectively_i, i=1,2 ... t_NMoment all visible GNSS navigation satellites Position and pseudorange；

In formulaIt is the earth's core body-fixed coordinate system when first, second, third satellite time-division is visible respectively Position；Be respectively when first, second, third satellite time-division that measurement obtains is visible by ionosphere and The revised pseudorange of tropospheric error, works as t_iWhen the satellite j at moment is invisible J=1,2,3；

In t_iMoment, coordinate of the satellite j under ECEF coordinate system are x⁽ⁱ⁾=(x⁽ⁱ⁾,y⁽ⁱ⁾,z⁽ⁱ⁾)^T, receiver clock-offsets δt_u, the actual position (u of receiver_x,u_y,u_z)^TAnd by ionosphere and the revised pseudorange of tropospheric errorBetween Shown in relationship such as formula (3)

Wherein c is the light velocity；

2) down-sampling, satellite position and puppet after obtaining down-sampling are carried out to the position of single GNSS navigation satellite and pseudorange Away from；

3) the observation data length of suitable MEO satellite or IGSO satellite is chosen

For MEO or IGSO satellite, enable positioning result better than 100m, data observation time span is greater than 48 minutes；

4) setting receiver positions iterative solution initial value

Setting receiver initial position is located at u₀=(0,0,0,0)^T, wherein u₀First three representation in components receiver position It sets, the 4th component is receiver clock-offsets；

5) iterative solution obtains receiver three-dimensional position

51) the data length n that iteration convergence threshold epsilon and single iteration need is set

Iteration convergence threshold epsilon is set as the positive value no more than 1, and the data length B after down-sampling is pressedIt calculates and obtains, wherein SOW₁Second, SOW in the week of initial time are acquired for data₂ The second in the week of finish time is acquired for data,It indicates to be rounded downwards；

52) maximum number of iterations Q is set_max, primary iteration number q and Primary receiver location updating value two norms | |Δu||₂；

53) setting Huber threshold value η is η ∈ [80,150]；

54) judge the convergence of iteration

When | | Δ u | |₂≤ ε or q > Q_maxWhen terminate iteration, and jump to step 6), otherwise continue to execute step 55)；

55) updated value of receiver location under Huber estimation model is solved

By n pseudorange observation data after down-samplingIt is arranged in the column vector of n × 1Receiver location estimation Value u is respectively to n co-ordinates of satellite after down-samplingDistance beBy l₁To l_nRow It is classified as the column vector of n × 1 l；Define n × 4 matrix A be

Wherein u_x、u_y、u_zFor three coordinate components of u,ForThree coordinate components, k=1 ..., n；

The optimal solution Δ u of solving optimization problem (4), φ (ζ) is Huber penalty function in formula (4), expression by (5) it provides, ζ indicates independent variable in formula (5)；

In formulaIt indicatesRow k；

56) receiver location estimated value u is updated_q=u_q-1+Δu；

57) it updates the value q=q+1 of q and goes to step 54)；

6) output receiver positioning result；

By the output result u after iteration convergence in step 5)_qAs the positioning result under final ECEF coordinate systemOr result u will be exported_qBe converted to the coordinate under longitude, latitude, height coordinate system.

The advantages of the present invention over the prior art are that:

1, present invention selection frequency stability first carries out data acquisition better than the clock of certain index, obtains different moments The position of single GNSS navigation satellite and pseudorange；Secondly, carrying out down-sampling to data, the MEO resolved for navigation position is chosen The observation data length of satellite or IGSO satellite；Finally, calculating the position of receiver itself by iterative solution and exporting positioning As a result.

2, the shortcomings that not being available when less than four observation satellites the present invention overcomes GNSS navigation locating method is realized At least only observe the high-precision navigator fix of single GNSS signal.

3, the GNSS satellite number that the method for the present invention needs to observe is few, positioning accuracy is high, has good real-time, can solve the moon Ball receiver only measures itself navigator fix problem when a GNSS satellite signal, while can realize multipath on the earth, more screenings Under baffle ring border, receiver observes high-precision navigator fix of the GNSS satellite quantity less than four when.

Detailed description of the invention

Fig. 1 is application scenario diagram of the invention；

Fig. 2 is the navigator fix flow chart that the present invention utilizes the mono- star signal of GNSS；

Fig. 3 is the positioning output result of GPS receiver；

Fig. 4 is the clock deviation and frequency stability in single star location data recording period inner receiver；

Fig. 5 is to utilize the receiver position error of the method for the present invention calculating with the variation of data record time；

Fig. 6 is the three-dimensional convergence graph estimated using the receiver location of measured data of the present invention processing experiment, five jiaos in figure Star represents the actual position of receiver；

Fig. 7 is that x, y, z coordinate estimated value connects with GPS in observation period in the experiment of GPS measured data using the present invention The error of receipts machine output result mean value.Fig. 7 (a) is the change curve that single star of the invention calculates x coordinate and GPS calculated result mean value Figure, Fig. 7 (b) are the change curves that single star of the invention calculates y-coordinate and GPS calculated result mean value, and Fig. 7 (c) is of the invention single The change curve of star calculating z coordinate and GPS calculated result mean value.

Specific embodiment

Step 1, selection frequency stability carries out data acquisition better than the clock of pre-set level, obtains different moments single The position of GNSS navigation satellite and pseudorange.The present embodiment use receiver clock-offsets such as Fig. 4 (a) shown in, by clock deviation calculate when Shown in clock stability such as Fig. 4 (b).The frequency stability index that the present embodiment receiver needs to meet can be obtained by Fig. 4 (b) are as follows: Allan standard deviation is better than 2.42 × 10 in 1s^-11, 100s is better than 1.24 × 10^-11, 1000s is better than 2.93 × 10^-12。

Enable Ω_x,y,zAnd Ω_ρRespectively t₁To t_NThe coordinate set and pseudorange collection of GNSS navigation satellite can be observed in moment It closes, records t respectively by formula (1) and formula (2)_i, i=1,2 ... t_NThe position of moment all visible GNSS navigation satellites and puppet Away from；

In formulaIt is the earth's core body-fixed coordinate system when first, second, third satellite time-division is visible respectively Position；It is when first, second, third satellite time-division of measurement acquisition is visible respectively by ionosphere With the revised pseudorange of tropospheric error, work as t_iWhen the satellite j at moment is invisible J=1,2,3；

In t_iMoment, coordinate of the satellite j under ECEF coordinate system are x⁽ⁱ⁾=(x⁽ⁱ⁾,y⁽ⁱ⁾,z⁽ⁱ⁾)^T, receiver clock-offsets δt_u, the actual position (u of receiver_x,u_y,u_z)^TAnd by ionosphere and the revised pseudorange of tropospheric errorBetween Shown in relationship such as formula (3)

Wherein c is the light velocity；

Step 2, down-sampling is carried out to the position of single GNSS navigation satellite and pseudorange, the satellite position after obtaining down-sampling And pseudorange.In order to reduce data processing complexity, while guaranteeing user's positioning accuracy, needs to carry out observational record data necessary Down-sampling.By multiple numerical experimentation, down-sampling can be carried out according to the sampling interval of 20s.

Step 3, the observation data length of suitable MEO satellite or IGSO satellite is chosen.

Navigator fix is carried out using single GNSS satellite signal, needs to acquire enough navigation satellite pseudorange values, with Guarantee the precision to receiver positioning result.For MEO or IGSO satellite, to enable positioning result better than 100m, data observation Time span needs to be greater than 48 minutes.

Step 4, setting receiver positions iterative solution initial value.

Setting receiver initial position is located at u₀=(0,0,0,0)^T, wherein u₀First three representation in components receiver position It sets, the 4th component is receiver clock-offsets；

Step 5, receiver three-dimensional position is iteratively solved.

5.1) the data length n that iteration convergence threshold epsilon and single iteration need is set

Iteration convergence threshold epsilon is set as the positive value no more than 1, and the data length B after down-sampling is pressedIt calculates and obtains, wherein SOW₁Second, SOW in the week of initial time are acquired for data₂ The second in the week of finish time is acquired for data,It indicates to be rounded downwards.

5.2) maximum number of iterations Q is set_max, primary iteration number q and Primary receiver location updating value two norms ||Δu||₂

5.3) Huber threshold value η is set

Huber threshold value η is set as η ∈ [80,150].

5.4) judge the convergence of iteration

When | | Δ u | |₂≤ ε or q > Q_maxWhen terminate iteration, and jump to step 6), otherwise continue to execute step 5.5)；

5.5) updated value of receiver location under Huber estimation model is solved

By n pseudorange observation data after down-samplingIt is arranged in the column vector of n × 1Receiver location estimation Value u is respectively to n co-ordinates of satellite after down-samplingDistance beBy l₁To l_nRow It is classified as the column vector of n × 1 l；Define n × 4 matrix A be

Wherein u_x、u_y、u_zFor three coordinate components of u,ForThree coordinate components, k=1 ..., n；

The optimal solution Δ u of solving optimization problem (4), φ (ζ) is Huber penalty function in formula (4), expression by (5) it provides, ζ indicates independent variable in formula (5).

In formulaIt indicatesRow k；

5.6) receiver location estimated value is updated

u_q=u_q-1+Δu

5.7) it updates the value q=q+1 of q and goes to 5.4

Step 6, output receiver positioning result.

By the output result u after iteration convergence in step 5_iAs the positioning result under final ECEF coordinate system Or it is converted into the coordinate under longitude, latitude, height coordinate system.

Effect of the invention combines the experimental result of following measured data processing to further illustrate and verify.

By receiving positioning of the single GPS satellite signal to receiver.About 50 points are had received using Novatel GPS receiver The data of clock choose G14 satellite therein, as single star observation.20s is that a sampled point observation data length is chosen for N=144.The positioning result of GPS receiver output is as shown in figure 3, taking its mean value is seat of the receiver in ECEF coordinate system It marks true value u=(- 1718.823864459562,4996.741515865431,3560.871613825784)^Tkm.Enable receiver Position initial value is u₀=(0,0,0,0)^T, maximum number of iterations N_max=50, two models of Primary receiver location updating vector are set Number | | Δ u | |₂=100, Huber threshold value η=80.The position error of localization method of the present invention and the pass for positioning required observation time System is as shown in Figure 5.The three-dimensional iterative convergence process of receiver positioning is as shown in fig. 6, X, Y, Z tri- under its ECEF coordinate system The calculating convergence result of coordinate is as shown in Figure 7.Positioning result after calculating to restrain

2. surveying the positioning experiment interpretation of result of GPS data list star

From figure 3, it can be seen that the position under the earth's core body-fixed coordinate system of GPS receiver output concentrates on target proximity, it is accurate It spends higher.By can be seen that in Fig. 5, merely with the observation data of a GPS satellite, positioning accurate can be improved by increasing observation time Degree, after observation time is greater than 48 minutes, position error is better than 100 meters.It can be seen that from Fig. 6 and Fig. 7, using the method for the present invention, Receiver location estimated value converges to rapidly near its true value from zero initial position.This shows that the method for the present invention is only receiving single High to the fast convergence rate of receiver positioning, estimated accuracy when GPS satellite signal, this method is feasible, correct, effective.

Claims (1)

1. a kind of navigation locating method using the mono- star signal of GNSS, it is characterised in that the following steps are included:

1) selection frequency stability carries out data acquisition better than the clock of pre-set level, obtains single GNSS navigation of different moments and defends The position of star and pseudorange；Enable Ω_x,y,zAnd Ω_ρRespectively t₁To t_NCan be observed in moment GNSS navigation satellite coordinate set and Pseudorange set records t by formula (1) and formula (2) respectively_i, i=1,2 ... the position of n-hour all visible GNSS navigation satellites And pseudorange；The pre-set level are as follows: Allan standard deviation is better than 2.42 × 10 in 1s^-11, 100s is better than 1.24 × 10^-11, 1000s is excellent In 2.93 × 10^-12；

In formulaIt is the earth's core body-fixed coordinate system position when first, second, third satellite time-division is visible respectively；It is when first, second, third satellite time-division of measurement acquisition is visible respectively by ionosphere and convection current Pseudorange after layer error correction, works as t_iWhen the satellite j at moment is invisible

In t_iMoment, coordinate of the satellite j under ECEF coordinate system are x⁽ⁱ⁾=(x⁽ⁱ⁾,y⁽ⁱ⁾,z⁽ⁱ⁾)^T, receiver clock-offsets δ t_u, Actual position (the u of receiver_x,u_y,u_z)^TAnd by ionosphere and the revised pseudorange of tropospheric errorBetween relationship As shown in formula (3)

Wherein c is the light velocity；

2) down-sampling, satellite position and pseudorange after obtaining down-sampling are carried out to the position of single GNSS navigation satellite and pseudorange；

3) the observation data length of suitable MEO satellite or IGSO satellite is chosen

For MEO or IGSO satellite, enable positioning result better than 100m, data observation time span is greater than 48 minutes；

4) setting receiver positions iterative solution initial value

Setting receiver initial position is located at u₀=(0,0,0,0)^T, wherein u₀First three representation in components receiver position, Four components are receiver clock-offsets；

5) iterative solution obtains receiver three-dimensional position

51) the data length n that iteration convergence threshold epsilon and single iteration need is set

Iteration convergence threshold epsilon is set as the positive value no more than 1, and the data length B after down-sampling is pressedIt calculates and obtains, wherein SOW₁Second, SOW in the week of initial time are acquired for data₂ The second in the week of finish time is acquired for data,It indicates to be rounded downwards；

52) maximum number of iterations Q is set_max, primary iteration number q and Primary receiver location updating value two norms | | Δ u ||₂；

53) setting Huber threshold value η is η ∈ [80,150]；

54) judge the convergence of iteration

When | | Δ u | |₂≤ ε or q > Q_maxWhen terminate iteration, and jump to step 6), otherwise continue to execute step 55)；

55) updated value of receiver location under Huber estimation model is solved

By n pseudorange observation data after down-samplingIt is arranged in the column vector of n × 1Receiver location estimated value u points It is clipped to n co-ordinates of satellite after down-samplingDistance beBy l₁To l_nIt is arranged as n × 1 column vector l；Define n × 4 matrix A be

Wherein u_x、u_y、u_zFor three coordinate components of u,ForThree coordinate components, k=1 ..., n；

The optimal solution Δ u of solving optimization problem (4), φ (ζ) is Huber penalty function in formula (4), and expression is given by (5) Out, ζ indicates independent variable in formula (5)；

In formulaIt indicatesRow k；

56) receiver location estimated value u is updated_q=u_q-1+Δu；

57) it updates the value q=q+1 of q and goes to step 54)；

6) output receiver positioning result；

By the output result u after iteration convergence in step 5)_qAs the positioning result under final ECEF coordinate systemOr Result u will be exported_qBe converted to the coordinate under longitude, latitude, height coordinate system.