US3680111A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radiometric aircraft landing system
Assignee: TELEDYNE RYAN AERONAUTICAL CO
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Filing: 1970-10-12
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Granted: 1972-07-25
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Expires: 1990-10-12
Abstract
Abstract An aircraft landing system employing passive radiometer apparatus mounted in an aircraft to scan a specially arranged ground target, which will provide directional and altitude guidance in the vicinity of an airfield. The ground target extends along the desired flight path and is designed to cause large differences between horizontally and vertically polarized radiometric noise, easily detected and analyzed by the radiometer. Portions of the ground target may have augmented noise sources in specific patterns, for marking and identification purposes. The radiometer output can provide visual or audible aid to manual control, or be used to operate an automatic pilot, or the like.
Inventors
- 👤 Derling G Killion
- 👤 Frank J Janza
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:30
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/74; G01S13/75; G01K; G01K11/00; G01K11/006; G01S1/00; G01S1/02
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
149 words
A radiometric aircraft landing system, comprising: a radiometer for installation in an aircraft and having an antenna with means for scanning the ground along the flight path; a ground target extending along the predetermined flight path to a landing strip, said ground target having radiometric noise polarizing elements arranged to provide a high contrast between horizontally and vertically polarized noise relative to the flight path; said radiometer having a receiver with means to compare the horizontally and vertically polarized noise signals and provide a difference output, and a sum output representing total noise received; discriminator means connected to said difference and sum outputs and providing a tuRn error signal; a source of altitude signal representing required altitude; comparator means connected to said source and to said sum output and providing an altitude error signal; and means for utilizing said turn and altitude error signals for control of an aircraft.
Claim 2
Dependent Claim
149 words
A radiometric aircraft landing system, comprising: a radiometer for installation in an aircraft and having an antenna with means for scanning the ground along the flight path; a ground target extending along the predetermined flight path to a landing strip, said ground target having radiometric noise polarizing elements arranged to provide a high contrast between horizontally and vertically polarized noise relative to the flight path; said radiometer having a receiver with means to compare the horizontally and vertically polarized noise signals and provide a difference output, and a sum output representing total noise received; discriminator means connected to said difference and sum outputs and providing a tuRn error signal; a source of altitude signal representing required altitude; comparator means connected to said source and to said sum output and providing an altitude error signal; and means for utilizing said turn and altitude error signals for control of an aircraft.
Claim 3
Dependent Claim
32 words
A radiometric aircraft landing system according to claim 1, and including inhibiting means responsive to said turn error signal to inhibit the altitude error signal when a turn error signal is present.
Claim 4
Dependent Claim
29 words
A radiometric aircraft landing system according to claim 1, wherein said ground target comprises a plurality of conductive slat elements spaced along and substantially perpendicular to the flight path.
Claim 5
Dependent Claim
27 words
A radiometric aircraft landing system according to claim 3, wherein the spacing between adjacent slat elements is less than one half wavelength of the effective radiometer frequency.
Claim 6
Dependent Claim
23 words
A radiometric aircraft landing system according to claim 4, wherein said slat elements are spaced above and substantially parallel to the ground surface.
Claim 7
Dependent Claim
21 words
A radiometric aircraft landing system according to claim 4, and including radiometric noise augmenting elements between certain of said slat elements.
Claim 8
Dependent Claim
19 words
A radiometric aircraft landing system according to claim 6, wherein said noise augmenting elements are arranged in specific patterns.
Claim 9
Dependent Claim
17 words
A radiometric aircraft landing system according to claim 6, wherein said noise augmenting sources are electric lamps.
Claim 10
Dependent Claim
43 words
A radiometric aircraft landing system according to claim 1, wherein said ground target comprises a flexible backing sheet transparent to radiometric noise and having a plurality of metallic slat elements thereon in spaced parallel relation along and substantially perpendicular to the flight path.
Claim 11
Dependent Claim
66 words
A radiometric aircraft landing system according to claim 1, wherein said ground target comprises a conductive grid having slat elements in spaced parallel relation along and substantially perpendicular to the flight path at a spacing of less than one half wavelength of the effective radiometer frequency, and longitudinal members interconnecting said slat elements with a spacing greater than one half wavelength of the effective radiometer frequency.
References Cited (Backward Citations)
US2502974A
Cited
US2458654A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |