US6169957B1
Expired / Lapsed
US
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Satellite signal receiver with speed computing integrity control
Assignee: Thales Avionics SAS
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Filing: 1997-06-03
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Granted: 2001-01-02
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Expires: 2017-06-03
Abstract
Abstract A satellite positioning receiver with velocity calculation integrity check. In order to increase the reliability of the velocity measurements by the receiver, it is proposed to measure the divergence between the measurements taken on n satellite director axes (n>4) and to given an alarm if this divergence exceeds a predetermined threshold. The divergence is measured by the mean square error between the calculated velocity vector and the velocities as measured along the director axes and projected on to the calculated velocity vector.
Inventors
- 👤 Jean-Pierre Arethens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:14
CPC Classifications
G; G01; G01S; G01S19/00; G01S19/01; G01S19/13; G01S19/20; G01S19/38; G01S19/39; G01S19/52
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
134 words
Satellite positioning receiver, comprising position calculation means which simultaneously use a number of n satellites at least equal to 4, receiver velocity calculation means which determine the velocity of the receiver along the director axes joining the receiver to each of the n satellites, and means for calculating a velocity vector of the receiver in a fixed terrestrial frame on the basis of the velocities along the director axes and on the basis of a matrix of vectors representing the directions of these director axes in the fixed frame, this receiver being characterized in that it furthermore comprises means for calculating a value representative of the divergence between the velocity measurements and the n director axes, this value representing information about the validity of the velocity vector of the receiver in the fixed frame.
Claim 2
Dependent Claim
134 words
Satellite positioning receiver, comprising position calculation means which simultaneously use a number of n satellites at least equal to 4, receiver velocity calculation means which determine the velocity of the receiver along the director axes joining the receiver to each of the n satellites, and means for calculating a velocity vector of the receiver in a fixed terrestrial frame on the basis of the velocities along the director axes and on the basis of a matrix of vectors representing the directions of these director axes in the fixed frame, this receiver being characterized in that it furthermore comprises means for calculating a value representative of the divergence between the velocity measurements and the n director axes, this value representing information about the validity of the velocity vector of the receiver in the fixed frame.
Claim 3
Dependent Claim
121 words
Receiver according to claim 1 , characterized in that it comprises means for calculating a velocity radius of protection for a given non-detection probability, on the basis of the formula RPE=max (Θ ½ ·ΔH i ·σ) for i=1 to n, where σ is an estimated velocity measurement noise value, Θ is a parameter selected as a function of number n from a table containing a respective numerical value for various possible values of n, and ΔH i is the difference between the value of the parameter PDOP, which is the position dilution of precision, for the constellation of n satellites and the value of this same parameter for the constellation of n-1 satellites from which the first satellite has been excluded.
Claim 4
Dependent Claim
25 words
Receiver according to claim 1 , characterized in that it comprises means for giving an alarm signal if the divergence measurement exceeds a determined threshold.
Claim 5
Dependent Claim
121 words
Receiver according to claim 3 , characterized in that it comprises means for calculating a velocity radius of protection for a given non-detection probability, on the basis of the formula RPE=max (Θ ½ ·ΔH i ·σ) for i=1 to n, where σ is an estimated velocity measurement noise value, Θ is a parameter selected as a function of number n from a table containing a respective numerical value for various possible values of n, and ΔH i is the difference between the value of the parameter PDOP, which is the position dilution of precision, for the constellation of n satellites and the value of this same parameter for the constellation of n-1 satellites from which the first satellite has been executed.
Claim 6
Dependent Claim
26 words
Receiver according to claim 3 , characterized in that the threshold is selected from a table containing one threshold value for each number n of satellites.
Claim 7
Dependent Claim
121 words
Receiver according to claim 5 , characterized in that it comprises means for calculating a velocity radius of protection for a given non-detection probability, on the basis of the formula RPE=max (Θ ½ ·ΔH i ·σ) for i=1 to n, where σ is an estimated velocity measurement noise value, Θ is a parameter selected as a function of number n from a table containing a respective numerical value for various possible values of n, and ΔH i is the difference between the value of the parameter PDOP, which is the position dilution of precision, for the constellation of n satellites and the value of this same parameter for the constellation of n-1 satellites from which the first satellite has been executed.
Claim 8
Dependent Claim
133 words
Satellite positioning receiver according to claim 1 , characterized in that the means for calculating the divergence value comprise means for calculating a residual velocity error ΔV equal to the norm ΔV=(|S·VD|) 2 of a vector product S·VD, where S is an n×n matrix, n being the number of satellites used, and VD is a measured velocity vector whose components are the n velocity measurements along the director axes between the receiver and each of the n satellites, the matrix S being calculated on the basis of the following formula, where H is the one n×4 matrix of the director cosines of these axes in a fixed terrestrial spatio-temporal frame, H T is the transpose of this matrix H, and I is the n×n identity matrix: S=I−H(H T ·H) −1 ·H T .
Claim 9
Dependent Claim
25 words
Receiver according to claim 7 , characterized in that it comprises means for giving an alarm signal if the divergence measurement exceeds a determined threshold.
Claim 10
Dependent Claim
121 words
Receiver according to claim 7 , characterized in that it comprises means for calculating a velocity radius of protection for a given non-detection probability, on the basis of the formula RPE=max (Θ ½ ×ΔH i ×σ) for i=1 to n, where σ is an estimated velocity measurement noise value, Θ is a parameter selected as a function of number n from a table containing a respective numerical value for various possible values of n, and ΔH i is the difference between the value of the parameter PDOP, which is the position dilution of precision, for the constellation of n satellites and the value of this same parameter for the constellation of n-1 satellites from which the first satellite has been executed.
Claim 11
Dependent Claim
37 words
Receiver according to claim 7 , characterized in that the means for calculating the divergence comprise means for calculating a normalized residue ΔV nr equal to ΔV/σ 2 , where σ is an estimated velocity measurement noise.
Claim 12
Dependent Claim
121 words
Receiver according to claim 10 , characterized in that it comprises means for calculating a velocity radius of protection for a given non-detection probability, on the basis of the formula RPE=max (Θ ½ ·ΔH i ·σ) for i=1 to n, where σ is an estimated velocity measurement noise value, Θ is a parameter selected as a function of number n from a table containing a respective numerical value for various possible values of n, and ΔH i is the difference between the value of the parameter PDOP, which is the position dilution of precision, for the constellation of n satellites and the value of this same parameter for the constellation of n-1 satellites from which the first satellite has been executed.
Claim 13
Dependent Claim
34 words
Receiver according to claim 10 , characterized in that the square of the velocity measurement noise is estimated on the basis of means for calculating a moving average, over several successive measurements, of ΔV/n-4.
Claim 14
Dependent Claim
121 words
Receiver according to claim 12 , characterized in that it comprises means for calculating a velocity radius of protection for a given non-detection probability, on the basis of the formula RPE=max (Θ ½ ·ΔH i ·σ) for i=1 to n, where σ is an estimated velocity measurement noise value, Θ is a parameter selected as a function of number n from a table containing a respective numerical value for various possible values of n, and ΔH i is the difference between the value of the parameter PDOP, which is the position dilution of precision, for the constellation of n satellites and the value of this same parameter for the constellation of n-1 satellites from which the first satellite has been executed.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2004-01-02 | 2004-07-03 | 2005-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-01-02 | 2008-07-03 | 2009-01-02 | $3760.00 | Window Closed / Lapsed |
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