Ultra-wideband detector systems for detecting moisture in building walls

• US 7,236,120 B2
• Filed: 03/31/2005
• Issued: 06/26/2007
• Est. Priority Date: 03/31/2005
• Status: Expired due to Fees

• Current Assignee: The United States of America As Represented By The Secretary of Commerce
• Original Assignee: The United States of America As Represented By The Secretary of Commerce
• Inventors: Healy, William, Van Doorn, Eric
• Primary Examiner(s): Sotomayor; John B.
• Application Number:
  US11/094,312
• Publication Number:
  US 20050179578A1
• Time in Patent Office: 817 Days
• Field of Search: 342/21, 342/22, 342/27, 342/85, 342/95, 342/115, 342/132, 342/134, 342/137
• 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 13/88 Radar or analogous systems specially adapted for specific applications electromagnetic prospecting or detecting of objects, e.g. near-field detection, G01V3/00
• CPC Class Codes: G01S 13/90 using synthetic aperture techniques , e.g. synthetic aperture radar [SAR] techniques
• CPC Class Codes: G01V 3/12 operating with electromagnetic waves operating with millimetre waves G01V8/005

Abstract

A non-destructive detection method and system enables detecting a moisture patch located inside a building wall or the like. A transmitter generates a series of ultra-wideband pulses while an ultra-wideband antenna unit, preferably in the form of an antenna array including a plurality of switchable antenna pairs, directs the pulses toward the building structure so that the pulses are reflected therefrom, and receives the reflected pulses. A receiver processes the reflected pulses received by the antenna unit and produces a corresponding output. A controller controls the operation of the transmitter, receiver and antenna unit, and analyzes the output of the receiver for the presence of moisture inside of the building wall.

Claims

1. A non-destructive detection system for detecting moisture inside of a building structure which is not visible from outside of the structure, said system comprising:

a transmitter for generating a series of ultra-wideband pulses;

an ultra-wideband antenna unit for directing the pulses toward the building structure so that the pulses are reflected therefrom, and for receiving the reflected pulses;

a receiver for processing the reflected pulses received by said antenna unit and for producing a corresponding output; and

a controller for controlling said transmitter, said receiver and said antenna unit and for analyzing said output of said receiver for the presence of moisture inside of the building structure,

said ultra-wideband antenna unit comprising means for providing a plurality of different antenna locations relative to the building structure and means for receiving reflected pulses from the different antenna locations relative to the building structure.

2. A system as claimed in claim 1 wherein said ultra-wideband antenna unit comprises a fixed ultra-wideband antenna array comprising a plurality of antennas individually switchable between operation as a transmitting antenna and operation as a receiving antenna so as to enable creation of said plurality of different antenna locations relative to the building structure.

3. A system as claimed in claim 2 further comprising electronic switching means for controlling switching of said plurality of antennas.

4. A system as claimed in claim 3 wherein said switching means comprises a switching unit integrated with the antenna array.

5. A system as claimed in claim 2 wherein said controller generates a synthetic aperture image based on the output of said receiver for said plurality of antenna locations.

6. A system as claimed in claim 2 wherein the controller controls the transmitter, the receiver and the switching of the antenna array so as to produce a plurality of different antenna scans involving a plurality of different transmitting and receiving antenna pairs, averages the output of the receiver over time for each scan, lines up all of the plurality of scans in time, and further processes the plurality of scans after the scans have been lined up.

7. A system as claimed in claim 1 wherein the controller generates a three-dimensional representation of moisture within said structure.

9. A system as claimed in claim 1 wherein said transmitter generates said pulses at a rate of on the order of 10 million pulses per second and said controller averages return pulses to eliminate the effect of random noise.

8. A system as claimed in 7 wherein the structure comprises a building wall, and said controller generates a three-dimensional representation of the moisture state of the wall.

10. A method for non-destructive detection of moisture inside of a building structure, said method comprising:

generating a series of ultra-wideband pulses;

using an ultra-wideband antenna unit to direct the pulses toward the building structure so that the pulses are reflected therefrom, and to receive the reflected pulses, said ultra-wideband antenna unit receiving reflected pulses from different antenna locations relative to the building structure;

processing the reflected pulses received by the antenna unit and producing a corresponding output; and

analyzing said output of said receiver for the presence of moisture inside of the building structure, the ultra-wideband antenna unit comprising an ultra-wideband antenna array positioned at a fixed location on one side of the building structure and comprising a plurality of antennas individually switchable between operation as a transmitting antenna and operation as a receiving antenna, and at least some of said antennas of the antenna array being switched to create of a plurality of different antenna locations relative to the building structure.

11. A method as claimed in claim 10 wherein a electronic switching means is used to control switching of the plurality of antennas.

12. A method as claimed in claim 10 further comprising generating a synthetic aperture image based on said output for the plurality of antenna locations.

13. A method as claimed in claim 10 wherein the transmitter, the receiver and the switching of the antenna array are controlled so as to produce a plurality of different antenna scans involving a plurality of different transmitting and receiving antenna pairs, said output is averaged over time for each scan, all of the plurality of scans are lined up in time, and the plurality of scans are further processed after the scans have been lined up.

14. A method as claimed in claim 10 wherein said plurality of antennas provide a plurality of different antenna locations, and a synthetic aperture image is generated based on said output for said plurality of antenna positions.

15. A method as claimed in claim 10 wherein a three-dimensional representation of a feature of interest within said structure is generated.

16. A method as claimed in claim 15 wherein the structure comprises a building wall, and a three-dimensional representation of the moisture state of the wall is generated.

17. A method as claimed in claim 10 wherein said transmitter generates said pulses at a rate of on the order of 10 million pulses per second and wherein return pulses are averaged to eliminate the effect of random noise.

18. A non-destructive detection system for detecting moisture inside of a building structure which is not visible from outside of the structure, said system comprising:

a transmitter for generating a series of ultra-wideband pulses;

an ultra-wideband antenna unit for directing the pulses toward the building structure so that the pulses are reflected therefrom, and for receiving the reflected pulses;

a receiver for processing the reflected pulses received by said antenna unit and for producing a corresponding output; and

a controller for controlling said transmitter, said receiver and said antenna unit and for analyzing said output of said receiver for the presence of moisture inside of the building structure, said ultra-wideband antenna unit comprises a fixed ultra-wideband antenna array comprising a plurality of antennas individually switchable between operation as a transmitting antenna and operation as a receiving antenna so as to enable creation of said plurality of different antenna locations relative to the building structure.

19. A non-destructive detection system for detecting moisture inside of a building structure which is not visible from outside of the structure, said system comprising:

a transmitter for generating a series of ultra-wideband pulses;

an ultra-wideband antenna unit for directing the pulses toward the building structure so that the pulses are reflected therefrom, and for receiving the reflected pulses;

a receiver for processing the reflected pulses received by said antenna unit and for producing a corresponding output; and

a controller for controlling said transmitter, said receiver and said antenna unit and for analyzing said output of said receiver for the presence of moisture inside of the building structure,

said antenna unit including a plurality of antennas positioned at a plurality of different antenna locations and said controller generating a synthetic aperture image based on the output of said receiver for said plurality of antenna locations.