US3722272A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Clear air turbulence detectors
Assignee: UK Secretary of State for Defence
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Filing: 1971-07-09
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Granted: 1973-03-27
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Expires: 1991-07-09
Abstract
Abstract A radiometer for use in aircraft as part of a clear air turbulence detector apparatus, constructed to provide signals representing the atmospheric temperatures of at least three regions ahead of the aircraft and centered about sight-lines having different angles of elevation or declination with respect to the aircraft, is connected to means for deriving a temperature-difference signal indicating the difference between the measured temperature of a central one of the regions and an average of the measured temperatures of two regions on opposite sides of the central region. The apparatus preferably includes a correction-signal deriving circuit for deriving a correctionsignal dependent upon the local tropopause height at the time of flight and the altitude of the regions subject to temperature measurement and a display for indicating when the temperaturedifference signal differs significantly from the correction signal.
Inventors
- 👤 Pherson A Mc
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:33
CPC Classifications
G; G01; G01J; G01J5/00; G01J5/0014; G01W; G01W1/00; G01W2001/003
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
108 words
A clear air turbulence detector apparatus for use in an aircraft comprising a radiometer constructed to provide signals respectively representing the mean temperatures of at least three regions in the atmosphere ahead of the aircraft and centered about sight-lines having different angles of elevation with respect to the aircraft, and calculation means connected to the radiometer for subtracting the measured mean temperature of a central one of the regions from an average of the measured mean temperatures of two regions on opposite sides of the central region thereby to produce a temperature difference signal indicating the probability of encountering clear air turbulence in the neighborhood of said regions.
Claim 2
Dependent Claim
108 words
A clear air turbulence detector apparatus for use in an aircraft comprising a radiometer constructed to provide signals respectively representing the mean temperatures of at least three regions in the atmosphere ahead of the aircraft and centered about sight-lines having different angles of elevation with respect to the aircraft, and calculation means connected to the radiometer for subtracting the measured mean temperature of a central one of the regions from an average of the measured mean temperatures of two regions on opposite sides of the central region thereby to produce a temperature difference signal indicating the probability of encountering clear air turbulence in the neighborhood of said regions.
Claim 3
Dependent Claim
146 words
A clear air turbulence detector apparatus as claimed in claim 1 and also comprising: adjustable tropopause height input setting means, for providing a tropopause height signal representing the altitude of the tropopause in the atmosphere ahead of the aircraft, altimeter signal input means, for receiving an altimeter signal representing the altitude of the aircraft, correction-signal deriving means, connected to the said tropopause height input setting means and to the said altimeter signal input means, for deriving a correction-signal dependent on the said tropopause height signal and the said altimeter sIgnal and substantially equal to a value of the temperature-difference signal expected to be found in comparable measurements in clear, non-turbulent normal atmospheric conditions, and display means, connected to the said calculation means and to the said correction-signal deriving means, for indicating the occurrence of a significant difference between the said temperature-difference signal and the said correction-signal.
Claim 4
Dependent Claim
85 words
A clear air turbulence detector apparatus as claimed in claim 2, also comprising pitch angle input means for receiving a signal indicating any inclination of the central sight-line of the radiometer''s field of view, and wherein the said correction-signal deriving means is constructed and connected to derive a signal representing Zo, the altitude of the center of the said central region and then derive the said correction-signal as a function of the difference between the said signal representing Zo and the said tropopause height signal.
Claim 5
Dependent Claim
165 words
A clear air turbulence detector apparatus as claimed in claim 2 wherein the correction-signal deriving means comprises an electronic circuit for deriving a correction-signal Ts according to the set of equations: -TS k(3h/8 - Z2/2h) for Z < or = h/2 -TS k((1.5h - Z)2/4h) for Z > or = h/2 but < or = 3h/2 -TS 0 for Z > or = 3h/2 where h is the height of each of the said at least three regions, k is a constant proportional to the mean rate of decrease of temperature with increasing height below the tropopause, and Z is the difference in altitude between the actual position of the tropopause and the center of the central field of view of the radiometer, and means for subtracting the correction-signal from the said temperature-difference signal to form a discrepancy function signal T* which can indicate conditions associated with clear air turbulence but is comparatively insensitive to the normal temperature distribution in the vicinity of the tropopause.
Claim 6
Dependent Claim
41 words
A clear air turbulence detector apparatus as claimed in claim 1 and wherein the said radiometer comprises means for cyclically changing the radiometer''s effective field of view and thereby causing temperature measurements of the said three regions to be made sequentially.
Claim 7
Dependent Claim
50 words
A clear air turbulence detector apparatus as claimed in claim 5 and wherein the said radiometer comprises a reference surface and is constructed to make measurements of the said three regions sequentially in a cyclic sequence which also comprises at least one measurement of the reference surface in each cycle.
References Cited (Backward Citations)
US3402295A
Cited
US3427581A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |