Method for the multidimensional temporal kinematic filtering of radar blips, from antenna revolution to antenna revolution

• US 8,188,910 B2
• Filed: 12/01/2009
• Issued: 05/29/2012
• Est. Priority Date: 12/02/2008
• Status: Expired due to Fees

• Current Assignee: Thales SA
• Original Assignee: Thales SA
• Inventors: Reuillon, Philippe, Groenenboom, Albert, Moruzzis, Michel
• Primary Examiner(s): GREGORY, BERNARR E
• Application Number:
  US12/628,562
• Publication Number:
  US 20100134346A1
• Time in Patent Office: 910 Days
• Field of Search: 342 89-103, 342/175, 342/195, 342159-164, 342192-194, 342/196, 342/197, 342 13- 20, 342 73- 81, 348/571, 348/699, 382/100, 382/103
• US Class Current: 342/195
• CPC Class Codes: G01S 13/538 eliminating objects that have not moved between successive antenna scans, e.g. area MTi
• CPC Class Codes: G01S 13/72 for two-dimensional tracking, e.g. combination of angle and range tracking, track-while-scan radar
• CPC Class Codes: G01S 7/414 Discriminating targets with respect to background clutter

Abstract

The invention relates to the general field of the detection, notably the radar detection, of mobile or fixed targets. It consists of a method making it possible mainly to qualify the blips supplied by the processing subsystem of the detection system before the latter are analyzed to generate tracks, each track being assumed to represent the trajectory of a moving object that has been detected. According to the invention, an analysis duration is considered, and all of the blips detected during this period are considered. These blips are divided up into subsets, each subset corresponding to the blips that, during the analysis duration, have been detected in one and the same analysis channel defined by an initial position and a speed vector. The subsets formed in this way are then grouped together, one and the same group combining the subsets comprising blips for which the combined assertion of a plurality of attributes is verified.

Claims

1. A method for the multidimensional temporal kinematic filtering of blips applied to the blips detected during an analysis duration corresponding to a plurality of antenna revolutions, the filtering being performed by means of analysis channels each analysis channel defining the movement of a target model from an initial position corresponding to the start of the analysis duration, the position of the target model for a given antenna revolution being assigned an uncertainty interval said method comprising:

a first step of storage of the blips detected from antenna revolution to antenna revolution, the storage of the detected blips being done for a given number N of revolutions corresponding to the analysis duration;

a second step of grouping the stored blips into subsets, a subset comprising the blips located in one and the same analysis channel;

a third step of classifying the various subsets into a plurality of groups, each group corresponding to the subsets comprising blips for which the combined assertion of a plurality of attributes, the value of each attribute being integrated over the analysis duration, is verified;

a fourth step of qualifying the stored blips, a criterion for qualification of a given blip being defined by the membership of the blip to one or another of the groups;

a fifth step of selective transmission of the qualified blips, the conditions for transmission of a blip being dependent on the qualification of this blip.

2. The method according to claim 1, wherein the third step comprises classifying the various subsets in several groups, each group corresponding to the subsets comprising a number n of blips less than a given number P, different from one group to another;

the fourth step of qualification of the stored blips comprises qualifying each blip by an attribute characterizing the membership of the blip to the subsets of the various groups.

3. The method according to claim 2, wherein the fourth step of qualification of the blips comprises assigning an attribute to each stored blip an attribute whose value indicates the group gathering together the subsets, to which the blip belongs, that comprise the greatest number of blips.

4. The method according to claim 1, wherein the third step comprises classifying the various subsets in two groups, a first group corresponding to the subsets comprising a number n of blips less than a given number P and a second group corresponding to the subsets comprising a number of blips greater than or equal to P;

the fourth step of qualification of the stored blips comprises qualifying each blip by a binary attribute whose value characterizes its membership to a subset of one or another group.

5. The method according to claim 4, wherein the fourth step of qualification of the blips comprises assigning a binary attribute to each stored blip, an attribute of which one value indicates that the blip belongs to at least one subset classified in the second group and of which the other value indicates that it does not belong to any subset classified in this second group.

6. The method according to claim 5, wherein the fifth step of transmission of the blips to the radio-tracking transmits only the blips whose binary attributes indicate that these blips belong to at least one subset classified in the second group;

the other blips not being transmitted.

7. The method according to claim 5, wherein the fifth step of transmission of the blips to the radar-tracking transmits all the stored blips, each blip being transmitted with its binary attribute.

8. The method according to claim 4, wherein during the second step the instantaneous speed of each blip is taken into account, a blip being classified in an analysis channel at a given measurement instant t_i, only if its instantaneous speed is comparable to that defined for the target model that is embodied by the channel concerned.

9. The method according to claim 1, wherein each analysis channel used during the second step is defined as an area of multidimensional space (position, speed and time), —

defined by an initial position and an initial speed vector, and delimited at each measurement instant by a position uncertainty interval whose dimensions are a function of the accuracy, along each of the measurement axes, of the measurements carried out.

10. The method according to claim 9, wherein the analysis channels are determined by choosing a set of speed vectors and by considering for each speed vector an initial meshing of the space defined by a plurality of uncertainty intervals;

each interval being centred on a given point of this space, so as to cover all of this space.

11. The method according to claim 10, wherein the positions on which the various uncertainty intervals are centred are defined so that each interval is overlapped over half of its area by each of the neighbouring intervals.

12. The method according to claim 10, wherein the chosen speed vectors have an amplitude and a direction that are constant from one measurement instant to another, each analysis channel defined in this way characterizing the uniform rectilinear movement of a target model from an initial position.

13. The method according to claim 10, wherein, the speed associated with each blip being considered to be exact, the uncertainty interval that delimits a channel for a given measurement instant has constant dimensions.

14. The method according to claim 9, wherein the multi-dimensional space (position, speed, time) is defined by a time axis and a system of polar coordinates with the radar as its origin, the initial position being defined by a radial distance, a bearing position and an elevation position and the speed vector by a radial component, a bearing component and an elevation component.

15. The method according to claim 9, wherein the multi-dimensional space (position, speed, time) is defined by a time axis and a system of polar coordinates with the radar as its origin, the initial position being defined by a radial distance and a bearing position and the speed vector by a radial component and a bearing component.

16. The method according to claim 9, wherein the multi-dimensional space (position, speed, time) is defined by a time axis and a three-dimensional system of Cartesian coordinates with the radar as its origin, the initial position and the components of the speed vector being expressed in this system.

17. The method according to claim 9, wherein the multi-dimensional space (position, speed, time) being defined by a time axis and a two-dimensional system of Cartesian coordinates with the radar as its origin, the initial position and the components of the speed vector are expressed in this system.

18. The method according to claim 9, wherein during the second step the instantaneous speed of each blip is taken into account, a blip being classified in an analysis channel at a given measurement instant t_i, only if its instantaneous speed is comparable to that defined for the target model that is embodied by the channel concerned.

19. The method according to claim 1, wherein during the second step the instantaneous speed of each blip is taken into account, a blip being classified in an analysis channel at a given measurement instant t_i, only if its instantaneous speed is comparable to that defined for the target model that is embodied by the channel concerned.