Multi-target data processing for multi-receiver passive radars in an SFN or MFN mode
First Claim
1. A data processing method implemented by multistatic radar systems comprising a plurality of transmitters and receivers, each receiver being able to be associated with one or more transmitters to form one or more bistatic bases, each receiver producing, at successive times, successive frames of bistatic blips, the method generating and maintaining multi-receiver Cartesian tracks from the bistatic blips generated by the different receivers, said data processing method comprising:
- a first processing step during which said data processing method generates and maintains single-receiver Cartesian tracks, each single-receiver track being constructed from blips formed by a given receiver of the multistatic radar system;
a second processing step during which said data processing method generates and maintains multi-receiver Cartesian tracks, each multi-receiver track being derived from the merging of single-receiver tracks and being constructed from the blips forming the merged single-receiver tracks, with bistatic blips not having been used in the first processing step to construct a single-receiver track;
the duly generated single-receiver and multi-receiver tracks being updated as and when the frames of blips are produced by the different receivers;
the generated tracks, comprising a state vector, a covariance matrix associated with this vector and the list of the bistatic blips having contributed to their formation and their maintenance, being transmitted to the processing means operating downstream of the method.
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Abstract
The invention relates to a data processing method for a multistatic radar system comprising a plurality of transmitters and receivers, each receiver being associated with one or more transmitters so as to form one or more bistatic bases. According to the invention, the method involves producing and sustaining multi-receiver Cartesian tracks from bistatic blips produced by the various receivers, and comprises: a first step in which mono-receiver Cartesian tracks are produced and sustained, each mono-receiver track consisting of blips formed by a given receiver; and a second step in which multi-receiver Cartesian tracks are produced and sustained, each multi-receiver track being constituted by merging the mono-receiver tracks together and with bistatic blips which have not been associated with a mono-receiver track. The produced tracks are transmitted together with the attributes thereof to processing means operating upstream from the method.
31 Citations
15 Claims
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1. A data processing method implemented by multistatic radar systems comprising a plurality of transmitters and receivers, each receiver being able to be associated with one or more transmitters to form one or more bistatic bases, each receiver producing, at successive times, successive frames of bistatic blips, the method generating and maintaining multi-receiver Cartesian tracks from the bistatic blips generated by the different receivers, said data processing method comprising:
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a first processing step during which said data processing method generates and maintains single-receiver Cartesian tracks, each single-receiver track being constructed from blips formed by a given receiver of the multistatic radar system; a second processing step during which said data processing method generates and maintains multi-receiver Cartesian tracks, each multi-receiver track being derived from the merging of single-receiver tracks and being constructed from the blips forming the merged single-receiver tracks, with bistatic blips not having been used in the first processing step to construct a single-receiver track; the duly generated single-receiver and multi-receiver tracks being updated as and when the frames of blips are produced by the different receivers;
the generated tracks, comprising a state vector, a covariance matrix associated with this vector and the list of the bistatic blips having contributed to their formation and their maintenance, being transmitted to the processing means operating downstream of the method.- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
the second sub step of the third step of the sub step for merging Cartesian tracks performing the same checks for the track B and for each bistatic base having been used to update the state of the track A.
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6. The method as claimed in claim 4, wherein the Cartesian track merging processing operation implements additional sub steps making it possible to take into account the age of the tracks A and B considered and to compare the age of these tracks to a minimum age, and to perform, depending on the results of the comparisons:
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neither the second step, nor the third step; only the second step; only the third step; the second step and the third step.
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7. The method as claimed in claim 2, wherein the processing operation, implemented by the first step for forming single-receiver Cartesian tracks, also includes an intermediate sub step, which checks whether the kinematic data, in the Cartesian space, extracted from the Cartesian tracks updated during the filtering sub step do not correspond to the type of target considered.
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8. The method as claimed in claim 2, wherein the processing operation, implemented by the second step for forming multi-receiver Cartesian tracks, also includes an intermediate sub step, which checks whether the kinematic data, in the Cartesian space, extracted from the Cartesian tracks updated during the filtering sub step do not correspond to the type of target considered.
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9. The method as claimed in claim 2, wherein the sub steps for testing the divergence of the maintained Cartesian tracks of the two processing steps implement an identical processing operation which considers a maximum number N of tests that can be performed for one and the same given frame n and a maximum number P of frames separating two consecutive tests on one and the same track, and which performs the test on a new track formed for a given frame n from the appearance of the frame n+P.
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10. The method as claimed in claim 2, wherein the sub steps for testing the divergence of the maintained Cartesian tracks performs the test on a given track if the covariance matrix Sk+1|k of the predicted state of the track considered fulfils the following threshold condition:
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det(Sk+1|k)≧
MaxDetin which MaxDet represents a given threshold.
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11. The method as claimed in claim 1, wherein the second processing step includes an additional sub step which performs, before association of the available single-receiver tracks with the existing multi-receiver tracks, a pre-updating of the existing multi-receiver tracks by means of the blips forming the current frame of multi-receiver bistatic blips k, this sub step considering, for each multi-receiver track, the single-receiver tracks having previously been associated with it for the preceding frames of multi-receiver blips k−
- 1 and in associating with the estimation of the multi-receiver track considered, the bistatic blips attached to these single-receiver tracks.
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12. The method as claimed in claim 1, wherein it includes a preliminary processing step consisting in performing a bistatic tracking of the bistatic blips produced by the different receivers forming the multistatic radar system and in assigning each of the blips forming a frame of bistatic blips k, a binary indicator indicating whether the blip considered is or is not associated with a bistatic track.
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13. The method as claimed in claim 2, wherein the sub steps for initializing single-receiver Cartesian tracks and for initializing multi-receiver Cartesian tracks initialize new tracks from the bistatic blips having been used to form bistatic tracks in the preliminary processing step.
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14. The method as claimed in claim 2, wherein the sub steps for associating the bistatic blips with the Cartesian tracks of the two processing steps use an association threshold γ
- according to whether the considered blip is or is not associated with a bistatic track.
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15. The method as claimed in claim 1, wherein it implements a preliminary processing operation to identify, for each blip, the transmitters from which it cannot have been obtained.
Specification