LOW ENERGY RADAR SYSTEM

• US 20110267219A1
• Filed: 01/31/2010
• Published: 11/03/2011
• Est. Priority Date: 01/31/2009
• Status: Active Grant

• Current Assignee: Elbit Systems Land and C4I - Tadiran Limited (Elbit Systems Limited)
• Original Assignee: Elbit Systems Land and C4I - Tadiran Limited (Elbit Systems Limited)
• Inventors: Picha, Guy, Kisliansky, Aviel, Isseroff, Amit
• Granted Patent: US 8,988,275 B2
• Time in Patent Office: Days
• US Class Current: 342/90
• CPC Class Codes: G01S 13/0209 Systems with very large relative bandwidth, i.e. larger than 10 %, e.g. baseband, pulse, carrier-free, ultrawideband
• CPC Class Codes: G01S 13/426 Scanning radar, e.g. 3D radar G01S13/66 takes precedence
• CPC Class Codes: G01S 13/56 for presence detection presence detection using near field arrangements G01V3/00, e.g. G01V3/08, G01V3/12; burglar, theft or intruder alarms with electrical actuation G08B13/22 - G08B13/26
• CPC Class Codes: G01S 7/414 Discriminating targets with respect to background clutter

Abstract

A low energy radar comprising a radar signal generator generating a radar signal, a transmitter transmitting the radar signal via a transmitting antenna, a receiving array including plurality of receiving antennas and a plurality of receivers, each antenna being coupled with a corresponding receiver, each of at least selected ones of the receivers receives a respective signal corresponding to reflections of the transmitted radar signal from a scene, a processor including a radar signal processor, the radar signal processor determines a scene reflections map, the scene reflections map includes values representing reflection characteristics from each selected location in the scene, a detector, detecting objects in the scene and the corresponding locations thereof according to the scene reflection map and a clutter map, the clutter map includes values representing clutter reflection characteristics from each selected location in the scene, and a power controller, after the transmitter transmitted the radar signal and the receiving array received the signal corresponding to reflections of the transmitted radar signal, the power controller shuts down at least one of the radar signal generator, the transmitter and the receiving array.

Claims

1. A low energy radar system comprising:

a radar signal generator generating a radar signal;

a transmitter, coupled with said radar signal generator, transmitting said radar signal via a transmitting antenna;

a receiving array including a plurality of receiving antennas and a plurality of receivers, each antenna being coupled with a corresponding receiver, each of at least selected ones of said receivers receives a respective signal corresponding to reflections of the transmitted radar signal from a scene;

a processor including;

a radar signal processor, coupled with said receiving array, said radar signal processor determines a scene reflections map, said scene reflections map includes values representing reflection characteristics from each selected location in said scene;

a detector, coupled with said radar signal processor, detecting objects in the scene and the corresponding locations thereof according to said scene reflection map and a clutter map, said clutter map includes values representing clutter reflection characteristics from each selected location in said scene; and

a power controller, coupled with said radar signal generator, with said transmitter, with said receiving array and with said processor, after said transmitter transmitted said radar signal and said receiving array received said signal corresponding to reflections of said transmitted radar signal, said power controller shuts down at least one of said radar signal generator, said transmitter and said receiving array.

2. The system according to claim 1, wherein said power controller further shuts down said processor after said radar signal processor processed the received signals and said detector detected said objects in the scene.

3. The system according to claim 1, wherein said radar signal processor is further coupled wit with said radar signal generator, and

wherein said radar signal processor further includes a frequency analyzer, said frequency analyzer at least analyzes the frequencies of the received signal and at least equalizing the received frequencies to correct the different attenuations of the received signal at different frequencies.

4. The system according to claim 1, wherein said radar signal processor includes a beam former, said beam former determines said scene reflections map.

5. The system according to claim 4, wherein each entry in said scene reflection map is associated with a selected location in said scene, each said entry includes a set of values representing reflection characteristics associated with the location corresponding to said entry.

6. The system according to claim 5, wherein said beam former determines reflection characteristics corresponding to each entry by determining a range map for each selected location, said range map includes the reflection characteristics of a plurality of directions at the selected range corresponding to the entry, said system orients in the direction corresponding to the entry.

7. The system according to claim 4, wherein said radar signal processor includes a clutter characteristics determinator, said clutter characteristics determinator determines said clutter map.

8. The system according to claim 7, in which each entry in said clutter map is associated with a corresponding selected location in said scene, each entry includes a set of values representing the clutter reflection characteristics respective of that location.

9. The system according to claim 8, wherein said signal parameters are selected from the group consisting of:

received energy levels;

the phase of the received signal;

the statistical characteristics of said received energy levels; and

the statistical characteristics of said phase of the received signal.

10. The system according to claim 8, wherein said clutter characteristics determinator determines, for each entry in the clutter map, a detection threshold respective of at least a selected portion of said clutter reflection characteristics.

11. The system according to claim 10, wherein said detector detects an object in the scene when the reflection characteristics the respective threshold thereof

12. The system according to claim 8, wherein said detector determines the probability that an object exists in a selected direction according to a detection probability function.

13. The system according to claim 12, wherein said probability function is predetermined.

14. The system according to claim 12, wherein said clutter characteristics determinator determines said detection probability function for each location in said scene, at least according to the clutter reflection characteristics associated with each location.

15. The system according to claim 7, wherein said clutter characteristics determinator further updates said clutter map according to said scene reflection map.

16. The system according to claim 15, wherein said clutter map is determined according to a long term weighted average of scene reflections maps.

17. The system according to claim 1, wherein said processor further includes an interference nuller, coupled with said beam former and with said detector, said interference nuller determines the effect of an interfering object on the signals received by each one of said receivers, and alleviating the effects of the interfering objects on said scene reflection map.

18. The system according to claim 17, wherein said Interference nuller determines the effects of the interfering object on each range map, and

wherein said beam former constructs said range maps while attenuating the reflections from the interfering object.

19. The system according to claim 1, wherein said radar signal processor further includes a compensator, coupled between said frequency analyzer and with said beam former, said compensator corrects the effects of physical phenomenon.

20. The system according to claim 19, wherein said physical phenomenon includes the effects of one antenna on the other antennas.

21. The system according to claim 20, wherein said physical phenomenon further includes effects of metallic objects in the vicinity of said on said receiving antennas and said transmitting antenna.

22. The system according to claim 20, wherein said physical phenomenon further includes effects of changes in temperature on said system.

23. The system according to claim 1, further comprising a tracker, coupled with said detector, said object tracker determining the object characteristics of the detected objects and determines object corresponding to targets from the detected objects according to said object characteristics.

24. The system according to claim 23, wherein said tracker further classifies said targets and determines targets of interests accordingly.

25. The system according to claim 24, wherein said power controller shuts down said tracker after said tracker determines object corresponding to targets and targets of interest.

26. The system according to claim 23, further comprising a communications transmitter coupled with a control station, with said detector with said tracker and with said power controller, said communications transmitters transmits information relating to the detected objects to said control station.

27. The system according to claim 26, wherein said communication transmitter is further coupled with said tracker, said communication transmitters further transmits information relating to said targets to said control station.

28. The system according to claim 27, wherein said power controller shuts down said communications transmitter after said communications transmitter transmitted said information.

30. A low energy radar system comprising:

a radar signal generator generating a radar signal;

a transmitting array including a plurality of transmitting antennas and a plurality of transmitters, each antenna being coupled with a corresponding transmitter, each transmitter being coupled with said radar signal generator, selected ones of said transmitters sequentially transmitting a respective signal toward a selected direction in a scene;

a receiver, coupled with said radar signal generator, receiving reflected signals from said selected direction in said scene;

a processor including;

a radar signal processor, coupled with said receiver, said radar signal processor determines a scene reflections map, said scene reflections map includes values representing reflection characteristics from each selected location in said scene;

a detector, coupled with said radar signal processor, detecting objects and targets in the scene and the corresponding location thereof according to said scene reflection map and a clutter map, said clutter map includes values representing clutter reflection characteristics from each selected location in said scene; and

a power controller, coupled with said radar signal generator, with said transmitter, with said receiving array and with said processor, after said transmitter transmitted said radar signal and said receiving array received said signal corresponding to reflections of said transmitted radar signal, said power controller shuts down at least one of said radar signal generator, said transmitter and said receiving array.

31. Low energy radar method comprising the procedures of:

determining a clutter map of a scene

transmitting a radar signal toward said scene;

receiving by each of at least selected ones of antennas in an antenna array a respective signal corresponding to reflections of the transmitted signal from the scene;

processing the received signals to determine a scene reflection map; and

detecting objects in the scene and the locations thereof, at least according to the scene reflection map and the clutter map.

32. The method according to claim 31, further comprising the procedure of tracking the detected objects in the scene.

33. The method according to claim 32, further comprising the procedure of classifying the detected objects.

34. The method according to claim 31, wherein said procedure of processing said received signals includes the sub-procedures of:

analyzing and compensating the received signals;

determining a scene reflection map, each entry in said scene reflection map is associated with a selected location, each entry includes values corresponding to parameters corresponding to said received signals, each value being determined from a range maps corresponding to said entry, each range map includes the received signals parameters from a plurality of directions at the range associated with said entry;

Determining a clutter map and analyzing the statistical characteristics of the clutter in a scene; and

nulling the interferences in the scene.

35. the method according to claim 34, wherein said procedure of alleviating includes determining the effect of an interfering object on the signals received by each one of said receivers, and determining the effects of the interfering object on each range map,

wherein said each said range maps is re-constructed for each selected location while nulling the reflections of the interfering object.