Low cost, high performance radar networks

• US 20110205103A1
• Filed: 03/01/2011
• Published: 08/25/2011
• Est. Priority Date: 04/20/2005
• Status: Active Grant

• Current Assignee: Sicom Systems Limited
• Original Assignee: Sicom Systems Limited
• Inventors: Premji, Al-Nasir, Nohara, Timothy J., Weber, Peter T., Krasnor, Carl E., Ukrainec, Andrew M., Jones, Graeme S.
• Granted Patent: US 8,384,585 B2
• Time in Patent Office: Days
• US Class Current: 342/90
• CPC Class Codes: G01S 13/726 Multiple target tracking
• CPC Class Codes: G01S 13/87 Combinations of radar systems, e.g. primary radar and secondary radar
• CPC Class Codes: G01S 13/917 for marine craft or other waterborne vessels
• CPC Class Codes: G01S 13/937 of marine craft
• CPC Class Codes: G01S 7/003 Transmission of data between radar, sonar or lidar systems and remote stations
• CPC Class Codes: G01S 7/046 using an intermediate storage device, e.g. a recording/reproducing device
• CPC Class Codes: G01S 7/068 with data-rate converters preceding the display, e.g. flicker free display, constant brightness display G01S7/298 takes precedence
• CPC Class Codes: G01S 7/22 Producing cursor lines and indicia by electronic means
• CPC Class Codes: G01S 7/292 Extracting wanted echo-signals

Abstract

A real-time radar surveillance system comprises at least one land-based non-coherent radar sensor apparatus adapted for detecting maneuvering targets and targets of small or low radar cross-section. The radar sensor apparatus includes a marine radar device, a digitizer connected to the marine radar device for receiving therefrom samples of radar video echo signals, and computer programmed to implement a software-configurable radar processor generating target data including detection data and track data, the computer being connectable to a computer network including a database. The processor is figured to transmit at least a portion of the target data over the network to the database, the database being accessible via the network by at least one user application that receives target data from the database, the user application providing a user interface for at least one user of the system.

Claims

1. A real-time radar surveillance system comprising at least one land-based non-coherent radar sensor apparatus adapted for detecting maneuvering targets and targets of small or low radar cross-section, said radar sensor apparatus including:

a marine radar device;

a digitizer connected to said marine radar device for receiving therefrom samples of radar video echo signals;

a computer programmed to implement a software-configurable radar processor generating target data including detection data and track data, said computer being connectable to a computer network including a database,

said processor being configured to transmit at least a portion of said target data over said network to said database, said database being accessible via said network by at least one user application that receives target data from said database, said user application providing a user interface for at least one user of the system.

2. The system defined in claim 1 where said radar processor includes a detection processor providing target detection data, said detection processor being programmed to employ a detection threshold low enough to reliably detect small radar cross-section targets but that results in a large number of false alarms from interference including clutter.

3. The system defined in claim 2 wherein said detection processor is programmed to execute clutter suppression algorithms for suppressing interference from clutter.

4. The system defined in claim 3 wherein said clutter is taken from the group consisting of clutter from snow and ice cover over water, clutter from man-made structures, land clutter, weather clutter, and water clutter.

5. The system defined in claim 1 wherein said radar processor includes a track processor providing target track data.

6. The system defined in claim 5 where said track processor is programmed to use multiple-hypothesis testing (MHT) association algorithms to reliably associate target detection data into target track data.

7. The system defined in claim 5 where said track processor is programmed to use interacting multiple model (IMM) filtering to provide good track data for maneuvering targets.

8. The system defined in claim 1 where said radar processor includes a display processor that provides one or more plan-position-indictor (PPI) type displays for use by an operator or user.

9. The system defined in claim 1 wherein said radar sensor apparatus is one of a plurality of land-based non-coherent radar sensor apparatuses each adapted for detecting maneuvering targets and targets of small or low radar cross-section, each said radar sensor apparatus including:

a respective marine radar device;

a respective digitizer connected to said respective marine radar device for receiving therefrom samples of radar video echo signals;

a respective computer operatively connected to said respective digitizer and programmed to implement a respective software-configurable radar processor generating respective target data including detection data and track data, said respective computer being connectable to said computer network,

said respective software-configurable radar processor being configured to transmit at least a portion of said respective target data over said network to said database, whereby said at least one user application may access target data stored in said database by said plurality of land-based non-coherent radar sensor apparatuses.

10. The system defined in claim 1 wherein said computer network is the global computer network known as the Internet.

11. The system defined in claim 1 wherein said radar sensor apparatus includes a software user interface that can be controlled by a user over said network to control one or more control features of said marine radar device.

12. The system defined in claim 1 where said marine radar device incorporates a monopulse antenna used with said radar processor to provide accurate height estimates for detected targets as part of target data.

13. The system defined in claim 1 where said user application runs on a computer located on a vessel, thereby allowing said user application to display target data generated by said radar processor.

14. The system defined in claim 1 where said radar processor is operated over said network by a remote radar operator.

15. The system defined in claim 1 where said radar processor is configured to provide unattended monitoring of a region of interest.

16. A real-time radar surveillance method comprising:

operating at least one land-based non-coherent radar sensor apparatus to detect maneuvering targets and targets of small or low radar cross-section, said radar sensor apparatus including a marine radar device, the operating of said radar sensor apparatus including digitizing samples of radar video echo signals received from said marine radar device;

operating a software-configurable radar processor to generate target data including detection data and track data; and

transmitting at least a portion of said target data over a computer network to a database.

17. The method defined in claim 16, further comprising operating a user application to receive target data from said database, additionally operating said user application to process the received target data, further operating said user application to provide a user interface for at least one user.

18. The method defined in claim 17, further comprising operating said user application to provide an integration of target data from said database.

19. The method defined in claim 18 wherein the operating of said user application to provide said integration of target data includes at least one of the following:

selecting target track data from individual ones of a plurality of said radar sensor apparatuses;

transforming target data to a common coordinate system;

executing multi-sensor data fusion algorithms.

20. The method defined in claim 19 wherein the executing of said multi-sensor data fusion algorithms includes identifying multiple redundant tracks belonging to the same target in regions of overlapping radar sensor coverage and selecting a single one of the multiple redundant tracks.

21. The method defined in claim 19 wherein the executing of said multi-sensor data fusion algorithms includes identifying multiple redundant tracks belonging to the same target in regions of overlapping radar sensor coverage and fusing the multiple redundant tracks into a single fused track.

22. The method defined in claim 19 wherein the executing of said multi-sensor data fusion algorithms includes identifying multiple segments of tracks belonging to a particular one of said targets and fusing said multiple segments into a single fused track for said particular one of said targets.

23. The method defined in claim 18, further comprising using said integration of target data to generate a composite radar picture or common operating picture of a surveyed area.

24. The method defined in claim 17, further comprising operating said user application to provide automated alerts associated with the behavior of a particular target or targets.

25. The method defined in claim 16, further comprising remotely controlling one or more control features of said marine radar device via said computer network.

26. A real-time radar surveillance system for detection and tracking of small maneuvering targets having a low radar cross-section, said system comprising:

\

an antenna;

a commercial off-the-shelf (COTS) marine radar transceiver;

a digitizer connected to said transceiver for receiving therefrom samples of radar video echo signals; and

a software-configured radar processor implemented on a COTS computer for producing target data including detection data and track data,

said radar processor including a detection processor generating said detection data and a track processor generating said track data,

said detection processor programmed to employ a detection algorithm to reliably detect small targets of interest.

said track processor being programmed to use association and track filtering algorithms to reliably track maneuvering targets.

27. The system in claim 26 where said radar processor includes a display processor that provides one or more plan-position-indictor (PPI) type displays for use by an operator or user.

28. The system in claim 27 where one of said PPI displays includes at least one of the following:

an overlay of radar echo on top of a geo-referenced map for enabling rapid selection of a location for each of a plurality of marine radars from where good radar coverage is obtainable;

an overlay of target data on a geo-referenced map;

an overlay of target data onto the radar intensity output of said detection processor;

target data represented as track symbols from one or more consecutive scans and detection symbols from one or more consecutive scans and where the operator can access track data associated with any track symbol; and

moving target echo trails that show for a given target a sequence of radar echoes from a respective sequence of scans color-coded so as to indicated the progression of time and hence target movement of said target over said sequence of scans.

29. The system defined in claim 26 where said antenna is a COTS marine radar antenna.

30. The system defined in claim 26 where said detection algorithm uses low thresholds, which result in higher false alarm rates.

31. The system defined in claim 26 where said antenna is a monopulse antenna, said radar processor being programmed to provide accurate height estimates for detected targets as part of target data.

32. The system defined in claim 26 wherein said detection processor includes clutter suppression algorithms for suppressing interference from clutter.

33. The system in claim 26, further comprising means for providing automatic notification to users of threats or situations of interest.

34. The system in claim 26 where said track data includes speed, heading, position, and track uncertainty information.

35. The system in claim 26 where track data includes radar echo intensity and size information.

36. The system defined in claim 26 where said radar processor stores target data in real-time for subsequent replay and reprocessing.

37. The system defined in claim 26 where said detection processor includes scan-to-scan integration, sector blanking, constant false alarm rate (CFAR) normalizing, clutter map processing, and plot extraction algorithms.

38. The system defined in claim 26 where said association algorithm is a multiple hypothesis testing (MHT) association algorithm.

39. The system defined in claim 26 where said track filtering algorithm is an interacting multiple model (IMM) filtering algorithm.

40. A system for remotely controlling a marine radar device having a display video stream, comprising:

radar controller hardware integrated with said marine radar device to provide at least one control signal to said marine radar device to cause said marine radar device to change its state;

a software interface operatively connected to said controller hardware via a computer network, for enabling a user or program to operate said radar controller hardware remotely over said network; and

means for capturing at least a portion of the display video stream of said marine radar device and for presenting the captured portion of said video stream to said user or said program to allow said user or said program to confirm that the state of said marine radar device changes in accordance with the operating of said software interface.

41. The system defined in claim 40 where at least one of said control signals takes the form of at least one of the following:

a switch state change; and

a serial code.

42. The system defined in claim 40 where the state of said marine radar device, subject to remotely controlled change, includes at least one of the following:

power status;

transmitting status; and

range setting.

43. A real-time radar surveillance method for detection and tracking of small maneuvering targets having a low radar cross-section, said method comprising:

operating a commercial off-the-shelf (COTS) marine radar transceiver to generate samples of radar video echo signals;

digitizing said samples of radar video echo signals;

operating a COTS computer to generate, from the digitized samples of radar video echo signals, target data including detection data and track data;

in the course of generating said detection data, employing a detection algorithm to reliably detect small targets of interest; and

in the course of generating said track data, using association and track filtering algorithms to reliably track maneuvering targets.

44. The method in claim 43, further comprising providing one or more plan-position-indictor (PPI) type displays for use by an operator or user.

45. The method in claim 44 where the providing of said one or more plan-position-indictor (PPI) type displays including producing one or more of the following:

an overlay of radar echo on top of a geo-referenced map for enabling rapid selection of a location for each of a plurality of marine radars from where good radar coverage is obtainable;

an overlay of target data on a geo-referenced map;

an overlay of target data onto the radar intensity output of said detection processor;

target data represented as track symbols from one or more consecutive scans and detection symbols from one or more consecutive scans and where the operator can access track data associated with any track symbol; and

moving target echo trails that show for a given target a sequence of radar echoes from a respective, sequence of scans color-coded so as to indicated the progression of time and hence target movement of said target over said sequence of scans.