Subsurface temperature measurement system

• US 8,485,722 B1
• Filed: 10/14/2010
• Issued: 07/16/2013
• Est. Priority Date: 10/14/2009
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation), University of South Florida (State University System of Florida)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Roeder, Robert S., Weller, Thomas M., Herzig, Paul A.
• Primary Examiner(s): Caputo, Lisa
• Assistant Examiner(s): WILLIAMS, JAMEL E
• Application Number:
  US12/904,855
• Time in Patent Office: 1,006 Days
• Field of Search: 374/122
• US Class Current: 374/122
• CPC Class Codes: G01K 11/006 using measurement of the effect of a material on microwaves or longer electromagnetic waves, e.g. measuring temperature via microwaves emitted by the object G01K17/003, G01J5/00 take precedence; measuring the effect of a material on X-, gamma- or particle radiation G01K11/30

Abstract

According to certain embodiments, a temperature measurement system includes a radiometer coupled to an antenna and a signal processor. The radiometer is operable to generate two or more signals representing electro-magnetic radiation received at a corresponding two or more differing frequencies. The signal processor receives the two or more signals from the radiometer while the antenna is placed adjacent to a surface of a substrate, and compares the two or more signals with one another to determine a brightness temperature of the substrate at a depth of the substrate from the antenna.

Claims

1. A temperature measurement system comprising:

an antenna of a surface contacting device that is adapted to be placed adjacent to a surface of a substrate;

a radiometer comprising at least two Dicke-type radiometer sub-circuits coupled to the antenna and each operable to generate a first signal representing a first electro-magnetic radiation signal at a first frequency and a second signal representing a second electro-magnetic radiation signal at a second frequency, the second frequency being different from the first frequency; and

a signal processor coupled to the radiometer and operable to;

receive the first signal and the second signal from the radiometer while the antenna is placed adjacent to the surface; and

compare a first signal strength of the first signal to a second signal strength of the second signal using an electro-magnetic propagation model to determine a brightness temperature at a depth of the substrate from the antenna.

2. A temperature measurement system comprising:

a radiometer coupled to an antenna and operable to generate a first signal representing a first electro-magnetic radiation signal at a first frequency and a second signal representing a second electro-magnetic radiation signal at a second frequency, the second frequency being is different from the first frequency; and

a signal processor coupled to the radiometer and operable to;

receive the first signal and the second signal from the radiometer while the antenna is placed adjacent to a surface of a substrate; and

compare the first signal to the second signal to determine a brightness temperature of the substrate at a depth of the substrate from the antenna.

3. The temperature measurement system of claim 2, wherein the signal processor is operable to compare the first signal to the second signal by determining a difference in a signal strength of the first signal relative to the signal strength of the second signal.

4. The temperature measurement system of claim 2, wherein the signal processor is operable to compare the first signal to the second signal by comparing a first signal strength of the first signal and a second signal strength of the second signal using an electro-magnetic propagation model.

5. The temperature measurement system of claim 2, wherein the substrate is a celestial object and the antenna is configured in a surface contacting device adapted to be placed adjacent to the surface of the celestial object.

6. The temperature measurement system of claim 5, wherein the surface contacting device comprises one or more of the following:

a boot;

a sandal;

a loafer;

a moccasin;

a slipper;

a sock; and

an end of a staff.

7. The temperature measurement system of claim 2, wherein the substrate comprises a man-made structure and the radiometer and the antenna are configured in a housing adapted to be placed adjacent to a surface of the man-made structure.

8. The temperature measurement system of claim 2, wherein the antenna comprises one or more of the following:

a dual-band spiral patch antenna;

a meta-material antenna;

a stacked patch antenna;

a fractal based antenna; and

a dipole antenna.

9. The temperature measurement system of claim 2, wherein the antenna is operable to receive the first electro-magnetic radiation signal or the second electro-magnetic radiation signal in the L-band of the electro-magnetic spectrum.

10. The temperature measurement system of claim 2, wherein the antenna is operable to receive the first electro-magnetic radiation signal or the second electro-magnetic radiation signal in the ultra high frequency (UHF) band of the electro-magnetic spectrum.

11. The temperature measurement system of claim 2, wherein the antenna is operable to receive the first electro-magnetic radiation signal or the second electro-magnetic radiation signal in the very high frequency (VHF) band of the electro-magnetic spectrum.

12. The temperature measurement system of claim 2, wherein the radiometer comprises at least two Dicke-type radiometer sub-circuits.

13. The temperature measurement system of claim 2, wherein the signal processor is operable to receive the first signal and the second signal from the radiometer while the antenna is placed in contact with the surface.

14. A temperature measuring method comprising:

receiving a first signal and a second signal from a radiometer while an antenna coupled to the radiometer is placed adjacent to a surface of a substrate, the antenna configured to generate the first signal representing a first electro-magnetic radiation signal at a first frequency and the second signal representing a second electro-magnetic radiation signal at a second frequency, the second frequency being different from the first frequency; and

comparing the first signal to the second signal to determine a brightness temperature of the substrate at a depth of the substrate from the antenna.

15. The temperature measuring method of claim 14, wherein comparing the first signal to the second signal further comprises determining a difference in a signal strength of the first signal relative to the signal strength of the second signal.

16. The temperature measuring method of claim 14, wherein comparing the first signal to the second signal further comprises comparing a first signal strength of the first signal to a second signal strength of the second signal using an electro-magnetic propagation model.

17. The temperature measuring method of claim 14, further comprising:

placing a surface contacting device configured with the antenna adjacent to a celestial object, the celestial object comprising the substrate.

18. The temperature measuring method of claim 17, wherein the surface contacting device comprises one or more of the following:

a boot;

a sandal;

a loafer;

a moccasin;

a slipper;

a sock; and

an end of a staff.

19. The temperature measuring method of claim 14, further comprising:

placing a housing adjacent to a man-made structure, the housing configured to house the radiometer and the antenna.

20. The temperature measuring method of claim 14, wherein the antenna comprises one or more of the following:

a dual-band spiral patch antenna;

a meta-material antenna;

a stacked patch antenna;

a fractal based antenna; and

a dipole antenna.

21. The temperature measuring method of claim 14, further comprising:

receiving, by the antenna, the first electro-magnetic radiation signal or the second electro-magnetic radiation signal in the L-band of the electro-magnetic spectrum.

22. The temperature measuring method of claim 14, further comprising:

receiving, by the antenna, the first electro-magnetic radiation signal or the second electro-magnetic radiation signal in the ultra high frequency (UHF) band of the electro-magnetic spectrum.

23. The temperature measuring method of claim 14, further comprising:

receiving, by the antenna, the first electro-magnetic radiation signal or the second electro-magnetic radiation signal in the very high frequency (VHF) band of the electro-magnetic spectrum.

24. The temperature measuring method of claim 14, wherein the radiometer comprises at least two Dicke-type radiometer sub-circuits.

25. The temperature measurement method of claim 14, further comprising:

receiving the first signal and the second signal from the radiometer while the antenna is placed in contact with the surface.