Dual mode ground penetrating radar (GPR)

• US 8,730,084 B2
• Filed: 11/29/2010
• Issued: 05/20/2014
• Est. Priority Date: 11/29/2010
• Status: Active Grant

• Current Assignee: King Abdul AZIZ City For Science and Technology, Technology Development Center King Abdulaziz City For Science and Technology
• Original Assignee: King Abdul AZIZ City For Science and Technology
• Inventors: Al-Khalefah, Tariq A., Almutairi, Khaled F. R., Utsi, Arne V.
• Primary Examiner(s): BYTHROW, PETER M
• Application Number:
  US12/955,231
• Publication Number:
  US 20120133543A1
• Time in Patent Office: 1,268 Days
• Field of Search: 342/22, 343/723, 343/739, 343749-752, 343/787, 343/788, 343790-793, 343/802
• US Class Current: 342/22
• CPC Class Codes: G01S 13/28 with time compression of received pulses
• CPC Class Codes: G01S 13/86 Combinations of radar systems with non-radar systems, e.g. sonar, direction finder
• 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 7/292 Extracting wanted echo-signals
• CPC Class Codes: G01V 3/12 operating with electromagnetic waves operating with millimetre waves G01V8/005
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 9/16 with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole H01Q9/44 takes precedence

Abstract

A dual mode ground penetrating radar includes an enclosure which houses radar electronics. The dual mode ground penetrating radar includes an enclosure housing radar electronics. The dual mode ground penetrating radar further includes a first antenna feed having ferrite loading and extending outside of the enclosure. The dual mode ground penetrating radar further includes a second antenna feed spaced apart from the first antenna feed, the second antenna feed having ferrite loading and extending outside of the enclosure. An RF signal is provided in at least one of the first and second antenna feeds by the radar electronics.

Claims

1. A dual mode ground penetrating radar, comprising:

an enclosure housing radar electronics;

a first antenna feed having ferrite loading and extending outside of the enclosure; and

a second antenna feed spaced apart from the first antenna feed, the second antenna feed having ferrite loading and extending outside of the enclosure,

wherein an RF signal is provided in at least one of the first and second antenna feeds by the radar electronics, and

the ferrite is a multi-turn low loss inductive ferrite which provides a high impedance at a point defining an end of the antenna and, beyond the end, lossy ferrites at regular intervals up to the radar electronics.

2. The dual mode ground penetrating radar of claim 1, wherein a first antenna and a second antenna are center fed resistively loaded dipoles to achieve broadband, non-resonating radar performance.

3. The dual mode ground penetrating radar of claim 1, wherein the radar electronics include a transmitter and a receiver, and the first antenna feed and the second antenna feed extending outside the enclosure are respectively connected to the transmitter and the receiver.

4. The dual mode ground penetrating radar of claim 1, wherein the radar electronics provide a 5 to 20 MHz frequency band range.

5. The dual mode ground penetrating radar of claim 4, wherein the receiver includes a field-programmable gate array (FPGA) for signal processing and performs convolution and averaging for increased sensitivity.

6. The dual mode ground penetrating radar of claim 1, further comprising a datalogger provided internally or externally of the enclosure for recording data.

7. The dual mode ground penetrating radar of claim 1, wherein a first antenna and a second antenna are devoid of electronics and are fed by coaxial cables with ferrites provided at intervals along the first and second antenna feeds to obtain desired broadband antenna frequency response, wherein a coaxial inner wire is independently used to carry the RF signal to a center of the antenna.

10. The dual mode ground penetrating radar of claim 1, further comprising a Global Positioning System (GPS) or the Differential Global Positioning System (DGPS) to provide location information for accurate mapping.

11. The dual mode ground penetrating radar of claim 1, further comprising a battery for powering the radar electronics.

12. The dual mode ground penetrating radar of claim 1, wherein the radar electronics enclosure and an enclosure of a power supply is a vehicle or a portable back pack.

15. The dual mode ground penetrating radar of claim 1, wherein a transmit pulse is spread out in time and compressed in the receiver and the receiver is synchronized to the transmitter so the receiver can determine when long and short pulses are sent to correlate internal processing, and the short transmit pulse is interleaved in the transmit sequence.

21. The dual mode ground penetrating radar of claim 1, wherein:

the ferrite is threaded along the first antenna feed and the second antenna feed in equal spacing at predetermined intervals for resistive loading to obtain a desired broadband antenna frequency response;

a sheathing of protective material is placed over the ferrite;

the ferrite has a lossy resistive part of permeability greater than a real inductive part at 1 MHz such that the ferrite acts as a resistor above 1 MHz;

the ferrite is selected to have a low μ

′ and

high μ

″

at a frequency of operation to make the ferrite behave more like a pure resistor than an inductor.

8. A dual mode ground penetrating radar, comprising:

an enclosure housing radar electronics;

a first antenna feed having ferrite loading and extending outside of the enclosure; and

a second antenna feed spaced apart from the first antenna feed, the second antenna feed having ferrite loading and extending outside of the enclosure,

wherein an RF signal is provided in at least one of the first and second antenna feeds by the radar electronics,

a first antenna and a second antenna are devoid of electronics and are fed by coaxial cables with ferrites provided at intervals along the first and second antenna feeds to obtain desired broadband antenna frequency response,

a coaxial inner wire is independently used to carry the RF signal to a center of the antenna, and

ferrite material of the ferrites is selected to have a low μ

′ and

high μ

″

at a frequency of operation to make the ferrite behave more like a pure resistor than an inductor.

9. The dual mode ground penetrating radar of claim 8, wherein μ

″

is about at least 3 times larger than μ

′

.

22. The dual mode ground penetrating radar of claim 8, wherein:

the ferrite is threaded along the first antenna feed and the second antenna feed in equal spacing at predetermined intervals for resistive loading to obtain a desired broadband antenna frequency response;

the ferrite has a lossy resistive part of permeability greater than a real inductive part at 1 MHz such that the ferrite acts as a resistor above 1 MHz; and

the ferrite is a multi-turn low loss inductive ferrite which provides a high impedance at a point defining an end of the antenna and, beyond the end, lossy ferrites at regular intervals up to the radar electronics.

13. A dual mode ground penetrating radar, comprising:

an enclosure housing radar electronics;

a first antenna feed having ferrite loading and extending outside of the enclosure; and

a second antenna feed spaced apart from the first antenna feed, the second antenna feed having ferrite loading and extending outside of the enclosure,

wherein an RF signal is provided in at least one of the first and second antenna feeds by the radar electronics and an outer screen is formed from the ferrite which is an antenna radiating element with wanted common mode resistive loss, wherein;

the ferrite is threaded along the first antenna feed and the second antenna feed in equal spacing at predetermined intervals for resistive loading to obtain a desired broadband antenna frequency response;

a sheathing of protective material is placed over the ferrite;

the ferrite has a lossy resistive part of permeability greater than a real inductive part at 1 MHz such that the ferrite acts as a resistor above 1 MHz;

the ferrite is selected to have a low μ

′ and

high μ

″

at a frequency of operation to make the ferrite behave more like a pure resistor than an inductor; and

the ferrite is a multi-turn low loss inductive ferrite which provides a high impedance at a point defining an end of the antenna and, beyond the end, the lossy ferrites at regular intervals up to the radar electronics.

14. A dual mode ground penetrating radar, comprising:

an enclosure housing radar electronics;

a first antenna feed having ferrite loading and extending outside of the enclosure; and

a second antenna feed spaced apart from the first antenna feed, the second antenna feed having ferrite loading and extending outside of the enclosure,

wherein an RF signal is provided in at least one of the first and second antenna feeds by the radar electronics and the ferrite is a 10 mm diameter toroid equivalent to a 22 ohm resistor from 5 to 15 MHz when threaded over a single wire.

16. A dual mode ground penetrating radar, comprising:

an enclosure for housing electronics, the electronics comprising;

a transmitter transmitting signals;

a receiver for receiving signals, the receiver includes a real time analog-to-digital converter and a field-programmable gate array (FPGA) for signal processing and averaging for increased sensitivity;

an antenna comprising a first antenna feed and a second antenna feed connected to the transmitter and the receiver, respectively, the first antenna feed and the second antenna feed being shielded with ferrite and the second antenna feed having a wire independently used to carry a RF signal to a center of the antenna; and

a battery providing power to the electronics, wherein;

the ferrite is selected to have a low μ

′ and

high μ

″

at a frequency of operation to make the ferrite behave more like a pure resistor than an inductor; and

the ferrite is a multi-turn low loss inductive ferrite which provides a high impedance at a point defining an end of the antenna and, beyond the end, lossy ferrites at regular intervals up to the radar electronics.

17. The dual mode ground penetrating radar of claim 16, wherein the battery is provided within the housing and the first antenna feed and the second antenna are separated by a non-metallic separator, and further comprising a datalogger for storing data received by the antenna.

18. The dual mode ground penetrating radar of claim 16, wherein the first antenna feed and the second antenna feed are provided in a side-by-side arrangement, separated by a non-metal separator.

19. The dual mode ground penetrating radar of claim 16, wherein the real time analog-to-digital converter is configured to sample all points on a single transmit pulse such that the FPGA can use remaining transmit pulses to average all tracks thereby reducing noise levels and the averaging is provided in real time prior to sending data to a datalogger.

20. The dual mode ground penetrating radar of claim 16, wherein:

the first antenna feed and the second antenna feed having ferrite loading; and

an outer screen formed from the ferrite is used as an antenna radiating element with wanted common mode resistive loss.