Mine detecting device having a housing containing metal detector coils and an antenna

• US 5,680,048 A
• Filed: 08/19/1996
• Issued: 10/21/1997
• Est. Priority Date: 08/19/1996
• Status: Expired due to Term

• Current Assignee: Net Results, Inc.
• Original Assignee: Net Results, Inc.
• Inventors: Wollny, Walter Thomas
• Primary Examiner(s): Snow, Walter E.
• Application Number:
  US08/699,353
• Time in Patent Office: 428 Days
• Field of Search: 324/326, 324/327, 324/328, 324/329, 342/22, 342/52, 342/459
• US Class Current: 324/329
• CPC Class Codes: F41H 11/12 Means for clearing land minefields; Systems specially adapted for detection of landmines
• 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 13/882 for altimeters measuring height using barometric means G01C5/06
• CPC Class Codes: G01S 7/027 Constructional details of housings, e.g. form, type, material or ruggedness
• CPC Class Codes: G01S 7/03 Details of HF subsystems specially adapted therefor, e.g. common to transmitter and receiver
• CPC Class Codes: G01V 3/15 specially adapted for use during transport, e.g. by a person, vehicle or boat
• CPC Class Codes: G01V 3/17 operating with electromagnetic waves operating with millimetre waves G01V8/005
• CPC Class Codes: H01Q 1/04 Adaptation for subterranean or subaqueous use
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop

Abstract

A device detects metallic and non-metallic objects on, flush with, or covered by the ground or other surfaces, or by interfering or obscuring structures or surfaces, using ground penetrating radar, a metal detector and a radiometer. It is specifically designed for detection of non-metallic mines. The coils of the metal detector are mounted in a multi-sensor module with the radar antenna in a co-boresighted and/or co-located arrangement, without degrading the performance of the metal detector or the ground penetrating radar. Preferably, the ground penetrating radar uses a feed and a collimation lens, (such as a Luneberg or Step Dielectric lens), as an antenna to reduce the change in the loss of signal strength due to changes in distance between the surface and the antenna, (for short distances). The collimated beam has approximately constant power for distances closer than twice the diameter of the lens. By using the lens with a ground penetrating radar, the antenna can be held somewhat farther from the ground, as well as eliminating "clutter" introduced as the antenna moves closer and farther from the ground. The sensor for the radiometer is co-located in the multi-sensor module. The sensors selected for the multi-sensor module employ different detection phenomena. Therefore, each sensor has its unique source for false alarms. The sensors'"'"' independent phenomenologies provide a synergism, which when processed, achieve an increase in probability of detection concurrent with a reduction in the false alarm rate for mines.

Claims

1. A mine detection system comprising:

a wand having a first end and an opposite second end;

a housing mounted onto said first end of said wand;

a signal processor supported by said wand;

a ground penetrating radar system in communication with said signal processor, said radar system including a transmitter, a receiver, and an antenna, said antenna having a first field of view; and

a metal detector system in communication with said signal processor, said metal detector system including metal detector coils, said metal detector coils having a second field of view;

said antenna and said metal detector coils being contained within said housing, said metal detector coils concentrically surrounding said antenna.

2. The mine detection system according to claim 1, wherein said first field of view of said antenna is substantially similar to said second field of view of said metal detector coils.

3. The mine detection system according to claim 1, wherein said antenna is selected from the group consisting of co-polarized, cross polarized, dual polarized, circularly polarized, and combinations thereof.

4. The mine detection system according to claim 1, wherein said first field of view of said antenna is offset from said second field of view of said metal detector coils by a predetermined angle.

5. The mine detection system according to claim 1, wherein said radar system is selected from the group consisting of stepped continuous wave, impulse, pulse, swept FM, continuous wave, monostatic, bistatic, balance bridge and combinations thereof.

6. A mine detection system comprising:

a wand having a first end and an opposite second end;

a housing mounted onto said first end of said wand;

a signal processor supported by said wand;

a ground penetrating radar system in communication with said signal processor, said radar system including a transmitter, a receiver, and an antenna, said antenna being contained within said housing and including an antenna feed and a collimation lens for producing a collimated beam, said antenna feed being mounted onto said lens; and

a metal detector system in communication with said signal processor, said metal detector system including metal detector coils contained within said housing.

7. The mine detection system according to claim 6, wherein said antenna is selected from the group consisting of co-polarized, cross polarized, dual polarized, circularly polarized, and combinations thereof.

8. The mine detection system according to claim 6, further including a lens support and spacer contained within said housing for supporting said lens.

9. The mine detection system according to claim 6, wherein said radar system is selected from the group consisting of stepped continuous wave, impulse, pulse, swept FM, continuous wave, monostatic, bistatic, balance bridge and combinations thereof.

10. The mine detection system according to claim 6, wherein said collimation lens is spherical.

11. The mine detection system according to claim 10, wherein said antenna feed is mounted onto said spherical lens at an angle offset from vertical.

12. The mine detection system according to claim 11, further including a radiometer in communication with said signal processor and said antenna feed.

13. The mine detection system according to claim 10, wherein two antenna feeds are mounted onto said lens.

14. The mine detection system according to claim 13, wherein said two antenna feeds are configured to operate within identical frequency bands.

15. The mine detection system according to claim 13, wherein said two antenna feeds are configured to operate in different frequency bands for increasing operational bandwidth of said radar system.

16. The mine detection system according to claim 10, wherein three antenna feeds are mounted onto said lens.

17. The mine detection system according to claim 16, wherein said three antenna feeds are configured to operate within identical frequency bands.

18. The mine detection system according to claim 16, wherein said three antenna feeds are configured to operate in different frequency bands for increasing operational bandwidth of said radar system.

19. The mine detection system according to claim 16, including a radiometer utilizing said three antenna feeds to produce an array of contiguous beams perpendicular to a scan direction.

20. An object detection system comprising a ground penetrating radar system, a metal detector system, a radiometer and a multi-sensor module including at least one radar antenna and metal detector coils, and wherein:

said radar antenna includes at least three antenna feeds and a spherical lens for producing a collimated beam;

said metal detector coils and said radar antenna are co-boresighted;

said radiometer utilizes at least two antenna feeds of said at least three antenna feeds to produce an array of contiguous beams perpendicular to a scan direction; and

said at least two antenna feeds are mounted on said spherical lens at a point offset from vertical by a predetermined angle.