US 6,603,422 B2Granted

Ground penetrating radar incorporating a real-time multi-target direction finding capability

OwnerJames Burton Wrightinventor

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Abstract

The Ground Penetrating Radar (GPR) system introduced in this application provides data from an underground medium of the same caliber as that provided by conventional radars in air or space applications. This includes direction as well as distance to all targets, and some indication of target shape and orientation, within a conical volume of the underground having a solid angle of about 90 degrees and a radial depth of about 100 feet, under ideal conditions, as depicted in FIG. 9. The key to this capability is depicted in FIG. 3, and is a hemispheric dome (6) which is placed against the smoothed surface (1) of the underground medium (2), and which has a relative dielectric constant (ER) substantially equal to that of the underground medium (2). A microwave horn antenna (3), which is filled with the same dielectric material (5) as that from which the dome is constructed, is placed against the surface (7) of this dome (6) and is moved back and forth (8), allowing the radar beam (9) of the horn antenna (3) to systematically scan the entire conical volume. The signal path of this radar antenna system is thus completely within a dielectric material having an (ER) comparable to that of the underground medium, from Coax-to-Waveguide transition through to the potential underground targets. No air-to-dielectric interface, with its reflections and refractive lensing effects, remains.

Claims1

Dependent claims

A ground penetrating radar (GPR) antenna system for locating objects in an underground medium, specifically for determining their direction as well as their depth from the radar antenna position, comprising:

(a) a special hemispherically-shaped dielectric dome, having a relative dielectric constant (ER) which is substantially equal to that of the underground medium of interest, for placement between the microwave horn antenna and the underground medium;
(b) a moldable putty, having an ER substantially equal to that of the underground medium of interest, consisting of a mixture of lime and petroleum jelly in proper proportions, for use in roughly smoothing the surface of the underground medium by filling in the deeper depressions;
(c) a malleable mixture of tiny glass spheres and petroleum jelly, mixed in such proportions as to achieve an ER substantially equal to that of the underground medium, for placement between the roughly smoothed surface of the underground medium and the flat side of the hemispheric dome;
(d) a conical horn-type of microwave antenna with its aperture shaped to fit against the curved surface of the hemispheric dome described in claim 1(a);
(e) a concave-convex lens for placement inside the aperture of the microwave horn antenna of claim 1(d), having an ER substantially equal to that of the hemispheric dome, for correction of the near-in focusing effect of the dome.
(f) a microwave horn-antenna completely filled (including the Coax-Waveguide Transistion) with a dielectric material having an ER substantially equal to that used in the hemispheric dome of claim 1(a).
(g) a microwave horn-antenna, with reflector, completely filled with a dielectric material having an ER substantially equal to that of which the hemispheric dome of claim 1(a) is made.

4 more elements

Facts

Application: 10/042,470Filed 10 Jan 2002 · us provisional application
Priority: 17 Nov 2000
Published: US 2002/0105455 A18 Aug 2002
Granted: 5 Aug 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

G01S 7/03
Of systems according to group G01S13/00: details of HF subsystems specially adapted therefor, e.g. common to transmitter and receiver
G01S 13/885
Radar or analogous systems specially adapted for specific applications: for ground probing
G01S 13/89
Radar or analogous systems specially adapted for specific applications: for mapping or imaging
G01S
Radio direction-finding