Dual transmitter visual display system

• US 5,905,455 A
• Filed: 10/23/1997
• Issued: 05/18/1999
• Est. Priority Date: 08/11/1995
• Status: Expired due to Fees

• Current Assignee: Zircon Corporation
• Original Assignee: Zircon Corporation
• Inventors: Long, James C., Marshall, Noel H. C., Heger, Charles E., Dodd, Paul W.
• Primary Examiner(s): Lobo, Ian J.
• Application Number:
  US08/956,920
• Time in Patent Office: 572 Days
• Field of Search: 367/87, 367/95, 367/99, 367/104, 367/107, 367/113, 367/910, 342/21, 342/22, 342/138, 342/142, 342/144, 73/625, 73/628, 324/67, 324/329
• US Class Current: 342/22
• CPC Class Codes: G01S 13/18 wherein range gates are used
• CPC Class Codes: G01S 13/87 Combinations of radar systems, e.g. primary radar and secondary radar
• CPC Class Codes: G01S 13/885 for ground probing prospecting or detecting using electromagnetic waves G01V3/12
• CPC Class Codes: G01S 7/03 Details of HF subsystems specially adapted therefor, e.g. common to transmitter and receiver
• CPC Class Codes: G01S 7/06 Cathode-ray tube displays or other two dimensional or three-dimensional displays
• CPC Class Codes: G01V 3/12 operating with electromagnetic waves operating with millimetre waves G01V8/005

Abstract

A cost-effective wideband radar system capable of locating objects, such as reinforcing steel rods, pipes, and air bubbles, objects located behind or within a volume of, e.g., concrete, soil, wood, or air. A sequence of wideband radar pulses are emitted without a carrier from each of two transmit antennas. The system includes a receiver that detects reflected pulse energy (echoes) that result when transmitted pulses encounter a change in material (e.g., an air to metal change or concrete to metal change). These amplitudes of the echoes are visually displayed along with the length of the transmit/echo path for each transmitter. The lengths of the displayed transmit/echo paths are compared to determine whether the system is centered over an object located within or behind a volume, the system being centered over the object when the transmit/echo paths for each transmitter/receiver combination are of equal length.

Claims

1. A detection system adapted for sensing a target, the system comprising:

a first signal transmitter transmitting a first signal, wherein the first signal is reflected from the target to provide a first echo;

a second signal transmitter transmitting a second signal, wherein the second signal is reflected from the target to provide a second echo;

a signal receiver receiving the first and second echoes; and

a display operatively connected to the receiver, the display showing along a first axis a first distance proportional to a transmit/echo path length between the first signal transmitter and the receiver and a second distance proportional to a second transmit/echo path length between the second signal transmitter and the receiver;

wherein the first signal is of a first phase and the first echo is of a second phase, and wherein the display provides an indication of whether the first echo is in phase with the first signal.

2. The system of claim 1, the display including a second axis along which is displayed a first symbol representing an amplitude of the first echo and a second symbol representing an amplitude of the second echo.

3. The system of claim 2, wherein the system is directly over the target when the first and second symbols are aligned along the first axis of the display.

4. The system of claim 3, the display further displaying an image of the distance and amplitude symmetrical about a center line of the display.

11. The system of claim 1, wherein the display includes an icon having selected alternative first and second appearances, wherein the selected one of the first and second appearances provides the indication of whether the first echo is in phase with the first signal.

12. The system of claim 11, wherein the display depicts the icon as solid in the first appearance and as hollow in the second appearance.

13. The system of claim 12, wherein the icon is depicted as solid if the target is solid.

14. The system of claim 12, wherein the icon is depicted as hollow if the target is hollow.

5. A detection system adapted for sensing a target, the system comprising:

a first transmitter transmitting a first signal, wherein the signal is reflected from the target to provide a first echo;

a second transmitter transmitting a second signal, wherein the second signal is reflected from the target to provide a second echo;

first signal receiver receiving a the first echo;

a second signal receiver receiving the second echo; and

a display operatively connected to the first and second receivers, the display showing along a first axis a first distance proportional to a first transmit/echo path length between the first transmitter and the first receiver and a second distance proportional to a second transmit/echo path length between the second transmitter and the second receiver;

wherein the first signal is of a first phase and the first echo is of a second phase, and wherein the display provides an indication of whether the first echo is in phase with the first signal.

6. A hand-held radar detection system movable by hand across a surface to locate a target behind the surface, the system comprising:

at least three antennas arranged with respect to the target to define a first transmit/echo path of a first length and a second transmit/echo path of a second length;

a receiver connected to at least one of the at least three antennas, the receiver providing a first output corresponding to the first length and a second output corresponding to the second length; and

a display operatively connected to the receiver, the display showing an icon along a first axis parallel to the surface, the display configured to move the icon along the first axis as the system is moved across the surface;

wherein the icon is displaced from a second axis perpendicular to the first axis by a distance proportional to the difference between the first and second lengths.

7. The system of claim 6, the display showing along the second axis a second distance proportional to a range between the system and the target.

8. The system of claim 6, wherein the receiver includes at least two receive antennas.

15. The system of claim 6, wherein the first-mentioned distance is equal to an offset by which the target is displace from the second axis, such that the icon, when displayed, remains still relative to the target as the system is moved over the surface.

9. A hand-held detection system for locating a target within a solid volume, the system comprising:

means for moving the system over a surface of the volume;

means for defining a first transmit/echo path of a first length and a second transmit/echo path of a second length;

means for providing a first output corresponding to the first length and a second output corresponding to the second length; and

means for displaying an icon along a first axis parallel to the surface, the display configured to move the icon along the first axis as the system is moved across the surface;

wherein the icon is displaced from a second axis perpendicular to the first axis by a distance approximately equal to an offset distance between a center line of the display means and a second line parallel to the center line and intersecting the target.

10. The system of claim 9, the means for displaying showing along a second axis a second distance proportional to a range between the system and the target.