Almost real-time sampling for ground-penetrating radar impulses

• US 9,581,690 B2
• Filed: 06/28/2012
• Issued: 02/28/2017
• Est. Priority Date: 06/28/2012
• Status: Active Grant

• Current Assignee: Tektronix Incorporated (Fortive Corp.)
• Original Assignee: Tektronix Incorporated (Fortive Corp.)
• Inventors: Knierim, Daniel G.
• Primary Examiner(s): McGue, Frank J
• Application Number:
  US13/536,813
• Publication Number:
  US 20140002292A1
• Time in Patent Office: 1,706 Days
• Field of Search: 342/22
• US Class Current: 1/1
• CPC Class Codes: G01S 13/003 Bistatic radar systems; Multistatic radar systems
• 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 13/222 using random or pseudorandom pulse repetition frequency
• CPC Class Codes: G01S 13/885 for ground probing prospecting or detecting using electromagnetic waves G01V3/12
• CPC Class Codes: G01S 7/411 Identification of targets based on measurements of radar reflectivity G01S7/415 takes precedence
• CPC Class Codes: G01S 7/5273 using digital techniques
• CPC Class Codes: G01V 3/12 operating with electromagnetic waves operating with millimetre waves G01V8/005

Abstract

A ground-penetrating RADAR-based system can include a transmitter configured to transmit multiple RADAR impulses and a receiver configured to receive a signal comprising return waves generated responsive to the transmitted RADAR impulses. The signal can include a direct wave portion and a reflected wave portion. The system can also include a processing unit configured to analyze the return waves by determining the direct wave portion, fitting the direct wave portion to determine parametric information corresponding to the return waves, determining the reflected wave portion, determining characteristics of the reflected wave portion based on the parametric information, and comparing the determined characteristics against known characteristics.

Claims

1. A ground-penetrating radar-based system, comprising:

a transmitter configured to transmit a plurality of radar impulses;

a receiver configured to receive a signal comprising return waves responsive to the transmitted plurality of radar impulses, the return waves comprising a direct wave portion and a reflected wave portion; and

a processing unit configured to;

determine the direct wave portion,

fit the direct wave portion to determine a relative time-shift of the reflected wave portion with respect to the direct wave portion,

determine the reflected wave portion, determine one or more characteristics of the reflected wave portion based on the determined relative time-shift,

compare the one or more characteristics against at least one known characteristic, and

determine, based on the comparison, that a match exists between the one or more characteristics and the at least one known characteristic, and

in response to the determination that the match exists, output a notification to an operator of the ground penetrating radar system to notify the operator of the match.

2. The ground-penetrating radar-based system of claim 1, wherein the processing unit is further configured to align the return waves based on the determined relative time-shift of the return waves, and wherein the processing unit is further configured to combine the aligned return waves to generate a higher resolution image of the return waves prior to determining the one or more characteristics of the reflected wave portion.

3. The ground-penetrating radar-based system of claim 1, wherein the transmitter is configured to transmit the plurality of radar impulses into a particular location of ground.

4. The ground-penetrating radar-based system of claim 3, wherein the processing unit is further configured to determine whether a particular device is present at the particular location based on the comparison of the one or more characteristics against at least one known characteristic.

5. The ground-penetrating radar-based system of claim 4, wherein the particular device comprises a land mine.

6. The ground-penetrating radar-based system of claim 1, wherein the transmitter comprises a transmitting antenna.

7. The ground-penetrating radar-based system of claim 1, wherein the receiver comprises a receiving antenna.

8. The ground-penetrating radar-based system of claim 1, wherein the processing unit comprises a field programmable gate array (FPGA).

9. The ground-penetrating radar-based system of claim 1, wherein the processing unit comprises an application-specific integrated circuit (ASIC).

10. The ground-penetrating radar-based system of claim 1, further comprising a vehicle housing the transmitter, the receiver, or both.

11. The ground-penetrating radar-based system of claim 1, further comprising a vehicle housing the processing unit.

12. The ground-penetrating radar-based system of claim 1, wherein the direct wave comprises a Nyquist-band-limited copy of a transmitted radar impulse sent directly to the receiver.

13. The ground-penetrating radar-based system of claim 1, wherein the plurality of radar impulses is transmitted at a non-uniform rate.

14. The ground-penetrating radar-based system of claim 1, wherein the notification includes an audible warning, a visual warning, or both.

15. A method of analyzing radar waves, comprising:

receiving a signal at a radar receiver, the signal comprising a plurality of return waves responsive to a plurality of radar impulses, each of the return waves comprising a direct wave portion and a reflected wave portion; and

analyzing, by a processing unit connected to the radar receiver, the plurality of return waves, the analyzing comprising;

identifying the direct wave portion of the return waves;

determining a relative time-shift of the reflected wave portion with respect to the direct wave portion, the determining of the relative time-shift including fitting the direct wave portion;

determining at least one characteristic of the reflected wave portion of the return waves based on the relative time-shift;

comparing the determined at least one characteristic against a known characteristic; and

determining, based on the comparison, that a match exists between the at least one characteristic and the known characteristic; and

in response to determining that the match exists, outputting a notification to an operator to notify the operator of the match.

16. The method of claim 15, further comprising:

transmitting, by a radar transmitter, the plurality of radar impulses before receiving the signal at the radar receiver.

17. The method of claim 16, wherein the plurality of radar impulses is transmitted into a particular area of ground.

18. The method of claim 17, wherein the signal is received from the particular area of ground.

19. The method of claim 18, wherein the analyzing further comprises:

determining the presence of a particular device in the ground based on the comparing.

20. The method of claim 19, wherein the particular device comprises a land mine.

21. The method of claim 16, further comprising creating the direct wave portion by sending a Nyquist-band-limited copy of a transmitted radar impulse directly from the radar transmitter to the radar receiver.

22. The method of claim 16, wherein transmitting, by a radar transmitter, the plurality of radar impulses comprises transmitting, by the radar transmitter, the plurality of radar impulses at a non-uniform rate.

23. The method of claim 15, wherein identifying the direct wave portion of the return waves comprises comparing a first one of the plurality of return waves against a previously determined pattern.

24. The method of claim 15, wherein the processing unit comprises a digitizer.

25. The method of claim 15, wherein the analyzing further comprises providing the determined at least one characteristic as output information.

26. The method of claim 15, wherein the notification includes an audible warning, a visual warning, or both.