GROUND RADAR SYSTEM

• US 3,831,173 A
• Filed: 12/17/1969
• Issued: 08/20/1974
• Est. Priority Date: 12/17/1969
• Status: Expired due to Term

• Current Assignee: Robert M. Lerner
• Original Assignee: Robert M. Lerner
• Inventors: Lerner, Robert M.
• Primary Examiner(s): Tubbesing, T. H.
• Application Number:
  US04/885,877
• Time in Patent Office: 1,707 Days
• Field of Search: 343/5R 324/5,6
• US Class Current: 342/22
• 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 13/885 for ground probing prospecting or detecting using electromagnetic waves G01V3/12
• CPC Class Codes: G01V 3/12 operating with electromagnetic waves operating with millimetre waves G01V8/005

Abstract

A system for locating underground objects, such as pipes, utility lines, culverts, ledges, and like kinds of underground discontinuities, including voids to depths in excess of 10 feet, includes a basic radar having a special antenna design which launches radiation that penetrates the earth and receives reflections from underground discontinuities for recordation in a moving vehicle.

Claims

1. In a ground radar system the method of determining the character of underground discontinuities, comprising the steps of:

generating a transient signal, conducting said signal through a finite segment of a twoparallel-element transmission line antenna, the elements of which lay in a plane parallel to the ground plane, passing the transmission line antenna over the ground in proximity to the ground, receiving reflected signals from discontinuities beneath the earth, and displaying said signals representative of underground discontinuities.

2. In a ground radar system the method of determining the character of underground discontinuities according to claim 1, which further includes recordation of said return signals on a sonar-type recorder.

3. In a ground radar system the method of determining the character of underground discontinuities according to claim 1 wherein said passing of the radiating segments of said transmission line over the ground includes dragging a sled containing said matched segments in a plane parallel to the ground, which plane is within a range of from 2 to 12 inches above the earth.

4. A ground radar system for determining the character of underground discontinuities, comprising:

means for generating a transient signal, means for conducting said signal through a finite segment of a two-parallel-element transmission line antenna, the elements of which lay in a plane parallel to the ground plane, means for passing the transmission lines over the ground in proximity to the ground, means for receiving reflected signals from discontinuities beneath the earth, and means for displaying said signals representative of underground discontinuities.

5. A ground radar system as in claim 4 wherein said means for conducting said signal to said two-parallel-element transmission line segment comprises a two-element tapered transmission line segment connected between said signal generating means and said two-parallel-element transmission line segment.

6. A ground radar system as in claim 5 wherein said means for conducting said signal comprises a two-element tapered transmission line segment connected between the other end of said parallel segment and a non-reflective load.

7. A ground radar system as in claim 6 wherein, the total electrical length of said parallel segment and said tapered segments is within an order of magnitude of a one-half wavelength of the center frequency of said signal.

8. A ground radar system for determining the character of underground diScontinuities according to claim 4, wherein said means for passing of the transmission line over the ground includes means for dragging a sled containing said transmission line in a plane parallel to the ground, which plane is within a range of from 2 to 12 inches above the earth.