US3641345A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Infrared radiometer apparatus for detecting clear-air turbulence from an aircraft
Assignee: NAT RES DEV
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Filing: 1970-03-05
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Granted: 1972-02-08
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Expires: 1990-03-05
Abstract
Abstract A radiometer apparatus suitable for use on a supersonic aircraft for clear-air turbulence detection includes means for operating at four selected wavelengths within an atmospheric absorption band, for example the 15 Mu band of carbon dioxide. At any particular height of the aircraft each of a set of filters used to select the four selected wavelengths has a weighting function which depends on the effective absorption coefficient of the atmosphere at that wavelength and each indicates which part of the atmosphere ahead provides a significant contribution to the radiation measured by the apparatus. At longer wavelengths the atmosphere is opaque and the radiometer apparatus receives radiation from immediately in front of the aircraft. By generating suitable functions from the outputs of radiation passed by two or more of the filters it is possible to detect turbulence of the type looked for.
Inventors
- 👤 Robert Coackley
- 👤 Michael Leslie Reynolds
- 👤 Clive Douglas Rodgers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:55
CPC Classifications
G; G01; G01J; G01J5/00; G01J5/02; G01J5/08; G01J5/0803; G01J5/0805; G01J5/0014
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
208 words
An infrared radiometer apparatus for detecting clear-air turbulence from an aircraft comprising: a first bandpass filter means for passing radiation from the atmosphere having only wavelengths in a first sub-band within an absorption band of a given component of the atmosphere, a second bandpass filter means for passing radiation from the atmosphere having only wavelengths in a second sub-band within said absorption band, said second sub-band having a different generalized absorption coefficient from said first sub-band, a third bandpass filter means for passing radiation from the atmosphere having only wavelengths in third sub-band within said absorption waveband, said third sub-band having a different generalized absorption coefficient from said first and said second sub-bands, infrared detector means located in the path of radiation passing through said first, second and third bandpass filter means and sensitive to radiation passing therethrough for generating first, second and third signals corresponding respectively to radiation having wavelengths in said first, second and third sub-bands, and quotient-indicating means responsive to the magnitude of said first, said second and said third signals and indicative of a quotient function representing the difference between the magnitude of said first signal and the magnitude of said second signal, the difference being divided by the magnitude of said third signal.
Claim 2
Dependent Claim
208 words
An infrared radiometer apparatus for detecting clear-air turbulence from an aircraft comprising: a first bandpass filter means for passing radiation from the atmosphere having only wavelengths in a first sub-band within an absorption band of a given component of the atmosphere, a second bandpass filter means for passing radiation from the atmosphere having only wavelengths in a second sub-band within said absorption band, said second sub-band having a different generalized absorption coefficient from said first sub-band, a third bandpass filter means for passing radiation from the atmosphere having only wavelengths in third sub-band within said absorption waveband, said third sub-band having a different generalized absorption coefficient from said first and said second sub-bands, infrared detector means located in the path of radiation passing through said first, second and third bandpass filter means and sensitive to radiation passing therethrough for generating first, second and third signals corresponding respectively to radiation having wavelengths in said first, second and third sub-bands, and quotient-indicating means responsive to the magnitude of said first, said second and said third signals and indicative of a quotient function representing the difference between the magnitude of said first signal and the magnitude of said second signal, the difference being divided by the magnitude of said third signal.
Claim 3
Dependent Claim
29 words
A radiometer apparatus as claimed in claim 1 and wherein one and the same detector is sensitive to incident radiation in said first, said second and said third sub-bands.
Claim 4
Dependent Claim
41 words
A radiometer apparatus as claimed in claim 1 and wherein said first, second and third bandpass filter means are operable with radiation from the atmosphere having only wavelengths in sub-bands within the carbon dioxide absorption waveband at and around 15 microns.
Claim 5
Dependent Claim
40 words
A radiometer apparatus as claimed in claim 1 having certain line of sight usable on an aircraft and further comprising means for stabilizing said line of sight against aircraft pitching, and means for scanning in azimuth said line of sight.
Claim 6
Dependent Claim
102 words
A radiometer apparatus as claimed in claim 1 and further comprising a first housing member for housing the optics of said radiometer apparatus, a second housing member rotatable within said first housing member about an axis perpendicular to said line of sight, a mirror within said second housing member for deflecting incoming radiation towards said filter means, a first gyroscopic means, sensitive to aircraft pitching, for controlling the angle between said mirror and said axis about which said second housing member is rotatable, and a second gyroscopic means for rotating said second housing member and scanning in azimuth saId line of sight.
Claim 7
Dependent Claim
139 words
A radiometer apparatus as claimed in claim 1 and further comprising: a fourth bandpass filter means for passing radiation from the atmosphere having only wavelengths in a fourth sub-band within said absorption waveband, said fourth sub-band having a different generalized absorption coefficient from that of said first, said second and said third sub-bands, said detector means being sensitive to radiation passing in said fourth sub-band for generating a fourth signal corresponding to radiation in said fourth sub-band, and wherein said quotient-indicating means is responsive also to the magnitude of said fourth signal corresponding to radiation having wavelengths in said fourth sub-band and indicative also of a quotient function representing the quotient of the difference between the magnitude of said first signal and said second signal and the difference between the magnitude of said third signal and said fourth signal.
Claim 8
Dependent Claim
29 words
A radiometer apparatus as claimed in claim 6 and wherein one and the same detector is sensitive to incident radiation in said first, said second and said third sub-bands,
Claim 9
Dependent Claim
28 words
A radiometer apparatus as claimed in claim 6 and wherein one and the same detector is sensitive to incident radiation in said first, second, third and fourth sub-bands.
Claim 10
Dependent Claim
42 words
A radiometer apparatus as claimed in claim 6 and wherein said first, second, third and fourth bandpass filter means are operable with radiation from the atmosphere having only wavelengths in sub-band within the carbon dioxide absorption waveband at and around 15 microns.
Claim 11
Dependent Claim
42 words
A radiometer apparatus as claimed in claim 6 and having a certain line of sight usable on an aircraft and further comprising: means for stabilizing said line of sight against aircraft pitching and means for scanning in azimuth said line of sight.
Claim 12
Dependent Claim
102 words
A radiometer apparatus as claimed in claim 10 and further comprising a first housing member for housing the optics of said radiometer apparatus, a second housing member rotatable within said first housing member about an axis perpendicular to said line of sight, a mirror within said second housing member for deflecting incoming radiation towards said filter means, a first gyroscopic means, sensitive to aircraft pitching, for controlling the angle between said mirror and said axis about which said second housing member is rotatable, and a second gyroscopic means for rotating said second housing member and scanning in azimuth said line of sight.
Claim 13
Dependent Claim
97 words
A radiometer apparatus as claimed in claim 6 and further comprising: a further set of bandpass filter means in addition to said first, second, third and fourth bandpass filter means, a filter housing member for housing said first, second, third and fourth bandpass filter means and said further set of bandpass filter means, and means for rotating said filter housing member and for removing said further set of bandpass filter means from location in the path of incoming radiation and presenting said first, second, third and fourth bandpass means in location of the path of incoming radiation.
Claim 14
Dependent Claim
44 words
A radiometer apparatus as claimed in claim 12 and wherein said indicating means contains a resettable integrator means for sampling signals corresponding to radiation passed by said first, second, third and fourth bandpass filter means and by said further set of bandpass filter means.
Claim 15
Dependent Claim
67 words
A radiometer apparatus as claimed in claim 13 and further comprising: logic timing means for timing rotations of said filter housing member and for timing reset of said resettable integrator between states corresponding to sampling of signals corresponding to radiation passed through said first, second, third and fourth bandpass filter means and sampling of signals corresponding to radiation passed through said further set of bandpass filter means.
Claim 16
Dependent Claim
79 words
A radiometer apparatus as claimed in claim 14 and wherein said first bandpass filter means is operable with radiatIon in a sub-band having a generalized absorption coefficient approximately twice that of the band radiation with which said second bandpass filter means is operable and said third bandpass filter means is operable with radiation in a sub-band having a generalized absorption coefficient large compared with that of the sub-band of radiation with which said second bandpass filter means is operable.
Claim 17
Dependent Claim
28 words
A radiometer apparatus as claimed in claim 14 and wherein one and the same detector is sensitive to incident radiation in said first, second, third and fourth sub-bands.
Claim 18
Dependent Claim
42 words
A radiometer apparatus as claimed in claim 14 and having a certain line of sight usable on an aircraft and further comprising: means for stabilizing said line of sight against aircraft pitching and means for scanning in azimuth said line of sight.
Claim 19
Dependent Claim
97 words
A radiometer apparatus as claimed in claim 17 and further comprising a first housing member for housing the optics of said radiometer apparatus, a second housing member rotatable within said first housing member about an axis perpendicular to said line of sight, a mirror for deflecting incoming radiation towards said filter means, a first gyroscopic means, sensitive to aircraft pitching, for controlling the angle between said mirror and said axis about which said second housing member is rotatable, and a second gyroscopic means for rotating said second housing member and scanning in azimuth said line of sight.
Claim 20
Dependent Claim
97 words
A radiometer apparatus as claimed in claim 1 and further comprising: a further set of bandpass filter means in addition to said first, second, third and fourth bandpass filter means, a filter housing member for housing said first, second, third and fourth bandpass filter means and said further set of bandpass filter means and means for rotating said filter housing member and for removing said further set of bandpass filter means from location in the path of incoming radiation and presenting said first, second, third and fourth bandpass means in location of the path of incoming radiation.
Claim 21
Dependent Claim
44 words
A radiometer apparatus as claimed in claim 19 and wherein said indicating means contains a resettable integrator means for sampling signals corresponding to radiation passed by said first, second, third and fourth bandpass filter means and by said further set of bandpass filter means.
Claim 22
Dependent Claim
67 words
A radiometer apparatus as claimed in claim 20 and further comprising: logic timing means for timing rotations of said filter housing member and for timing reset of said resettable integrator between states corresponding to sampling of signals corresponding to radiation passed through said first, second, third and fourth bandpass filter means and sampling of signals corresponding to radiation passed through said further set of bandpass filter means.
Claim 23
Dependent Claim
78 words
A radiometer apparatus as claimed in claim 21 and wherein said first bandpass filter means is operable in a sub-band having a generalized absorption coefficient approximately twice that of the sub-band of radiation with which said second bandpass filter means is operable and said third bandpass filter means is operable with radiation in a sub-band having a generalized absorption coefficient large compared with that of the sub-band of radiation with which said second bandpass filter means is operable.
Claim 24
Dependent Claim
41 words
A radiometer apparatus as claimed in claim 22 and wherein said first, second and third bandpass filter means are operable with radiation from the atmosphere having only wavelengths in sub-bands within the carbon dioxide absorption waveband at and around 15 microns.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-02-07 | 1975-08-09 | 1976-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-07 | 1979-08-09 | 1980-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-07 | 1983-08-09 | 1984-02-08 | $7700.00 | Window Closed / Lapsed |