US3689924A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reconnaissance and guidance microwave radio-metric system
Assignee: Individual
•
Filing: 1968-09-18
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Granted: 1972-09-05
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Expires: 1988-09-18
Abstract
Abstract A microwave radiometric system is provided for reconnaissance and guidance purposes which responds to polarized microwave radiations from the terrain under observation. The system utilizes such radiations to distinguish different materials in the observed area, and it may also be designed to use selected materials in the observed area for tracking purposes. The system to be described includes a sensitive radiometric receiver and directional antenna, and it utilizes a relatively simple linear processing system for the received signals, rather than the prior art ratio approach.
Inventors
- 👤 Philip J Caruso Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 07:44
CPC Classifications
G; G01; G01S; G01S3/00; G01S3/02; G01S3/14; G01S3/146
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
227 words
A microwave radiometric system including: a directional antenna capable of receiving radiation microwave signals emitted by different materials in an area under observation, certain of said microwave signals being polarized and said microwave signals having amplitudes related to the apparent temperatures of the said materials, and one of said signals representing background radiations of the aforesaid area; first radiometric detector channel means coupled to said antenna for receiving and detecting vertically polarized microwave signals (Tv) intercepted by said antenna; second radiometric detector channel means coupled to said antenna for receiving and detecting horizontally polarized microwave signals (Th) intercepted by said antenna; subtractor circuitry coupled to said first and second radiometric channel means for deriving a difference signal output (Tv-Th) in response to the output signals from said first and second radiometric detector channel means; and means including adder circuitry coupled to said subtractor circuitry and to at least one of said first and second radiometric detector channel means for producing an output (T) having an amplitude related to said background signals and which is below a particular threshold in the absence of a particular material in the area under observation and regardless of the mixture of other materials which may be present in the area under observation; and said output (T) exceeding the said threshold in the presence of said particular material in the area under observation.
Claim 2
Dependent Claim
227 words
A microwave radiometric system including: a directional antenna capable of receiving radiation microwave signals emitted by different materials in an area under observation, certain of said microwave signals being polarized and said microwave signals having amplitudes related to the apparent temperatures of the said materials, and one of said signals representing background radiations of the aforesaid area; first radiometric detector channel means coupled to said antenna for receiving and detecting vertically polarized microwave signals (Tv) intercepted by said antenna; second radiometric detector channel means coupled to said antenna for receiving and detecting horizontally polarized microwave signals (Th) intercepted by said antenna; subtractor circuitry coupled to said first and second radiometric channel means for deriving a difference signal output (Tv-Th) in response to the output signals from said first and second radiometric detector channel means; and means including adder circuitry coupled to said subtractor circuitry and to at least one of said first and second radiometric detector channel means for producing an output (T) having an amplitude related to said background signals and which is below a particular threshold in the absence of a particular material in the area under observation and regardless of the mixture of other materials which may be present in the area under observation; and said output (T) exceeding the said threshold in the presence of said particular material in the area under observation.
Claim 3
Dependent Claim
38 words
The microwave radiometric system defined in claim 1, and which includes a multiplier circuit interposed betweeN said subtractor circuitry and said adder circuitry to suppress the output (Tv-Th) from said subtractor in accordance with a particular constant (k).
Claim 4
Dependent Claim
32 words
The microwave radiometric system defined in claim 2, and which includes an incidence angle sensor unit coupled to said last-named circuit for setting said constant (k) in accordance with an incidence angle.
Claim 5
Dependent Claim
15 words
The microwave radiometric system defined in claim 1, in which said particular material is metal.
Claim 6
Dependent Claim
31 words
The microwave radiometric system defined in claim 2, in which said constant (k) is selected completely to suppress radiations derived from water or other highly polarized material, in said observed area.
Claim 7
Dependent Claim
43 words
The microwave radiometric system defined in claim 2, and which includes tracking means mechanically coupled to said antenna, and servo circuitry coupled to said adder circuitry and responsive to variations in said output (T) above the aforesaid threshold to control said tracking means.
Claim 8
Dependent Claim
17 words
The microwave radiometric system defined in claim 6, in which said antenna has multiple lobe directional characteristics.
Claim 9
Dependent Claim
26 words
The microwave radiometric system defined in claim 6, in which said antenna is controlled to provide a conically scanned directional beam in the area under observation.
Claim 10
Dependent Claim
18 words
The microwave radiometric system defined in claim 1, in which said antenna has multiple fixed beam directional characteristics.
Claim 11
Dependent Claim
18 words
The microwave radiometric system defined in claim 1, in which said antenna includes at least one scanning beam.
References Cited (Backward Citations)
US3028596A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-05 | 1976-03-06 | 1976-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-05 | 1980-03-06 | 1980-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-05 | 1984-03-06 | 1984-09-05 | $7700.00 | Window Closed / Lapsed |