Large scale imaging with spatially-coded waveforms

• US 7,504,984 B1
• Filed: 05/15/2007
• Issued: 03/17/2009
• Est. Priority Date: 03/30/2007
• Status: Active Grant

• Current Assignee: The United States of America As Represented By The Secretary of Agriculture
• Original Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Inventors: Mitra, Atindra K.
• Primary Examiner(s): Tarcza; Thomas H
• Assistant Examiner(s): Bythrow; Peter M
• Application Number:
  US11/803,813
• Time in Patent Office: 672 Days
• Field of Search: 342/22, 342/26.R, 342/26.A, 342/26.F, 342/59, 342/125, 342/132
• US Class Current: 342/22
• CPC Class Codes: G01S 13/003 Bistatic radar systems; Multistatic radar systems
• CPC Class Codes: G01S 13/26 wherein the transmitted pulses use a frequency- or phase-modulated carrier wave
• 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

Abstract

A system for locating earth cavities, or items in a building, or structural characteristics having a plurality of transmitters that generate at least a portion of a waveform. Each transmitter divides the waveform into sub-chirp intervals and transmits a known sub-chirp interval from a known location to contact an article of interest. The resulting sub-chirp intervals become a leakage signal that is then received and processed by a receiver. The receiver therein approximates a cavity size, article size, article composition, article location, earth cavity location, or other structural characteristic.

Claims

1. A system for locating earth cavities comprising:

a plurality of satellites based transmitters that generate a waveform;

each transmitter dividing the wave form into sub-chirp intervals;

each transmitter transmitting a known sub-chirp interval from a known location to contact the earth,

the resulting sub-chirp interval becoming a leakage signal; and

at least one receiver,

the receiver processing the plurality of leakage signals to approximate the earth cavity size, and location.

2. The system of claim 1 wherein the frequency waveform is from about 300 MHz to about 12 GHz.

3. The system of claim 1 wherein the receiver is located on a land vehicle or aircraft.

4. The system of claim 1 wherein the sub-chirp interval is from about 500 MHz to about 2,000 MHz and there are at least 3 sub-chirp intervals.

5. The system of claim 1 further including a means for extrapolating the plurality of the leakage signals to image the earth cavities.

6. A method for locating an object in a building with leakage points:

generating a waveform;

dividing the waveform into sub-chirp intervals;

transmitting the sub-chirp intervals from multiple known locations to contact the building and the leakage points, the resulting sub-chirp interval becoming a leakage signal;

receiving a plurality of leakage signals; and

processing the plurality of leakage signals to approximate the object size, and location.

7. The method of claim 6 wherein the processing further approximates the object composition.

8. The method of claim 6 wherein the transmitting is performed by a plurality of mini-unmanned aviation vehicles.

9. The method of claim 6 wherein the object includes an interior layout and the processing further approximates the internal layout.

10. An apparatus for approximating a building internal room structure and room contents, the apparatus comprising:

a plurality of transmitters that generate a waveform;

each transmitter dividing the wave form into sub-chirp intervals;

each transmitter transmitting a known sub-chirp interval from a known location to contact the building;

the resulting sub-chirp interval becoming a leakage signal;

a receiver for receiving a plurality of the leakage signals; and

a processor for extrapolating the plurality of the leakage signals to approximate the building internal room structure and room contents.

11. The apparatus of claim 10 wherein the plurality of transmitters and the receiver are mounted on a mini-unmanned aviation vehicle.

12. The apparatus of claim 11 wherein the mini-unmanned aviation vehicle is capable of both transmitting a sub-chirp interval and receiving a leakage signal.