Patent US3571572A successfully refreshed from Google Patents.
US3571572A
Expired / Lapsed
US
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Radiation balance horizon sensor with an earth tangency mask
Assignee: Barnes Engineering Co
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Filing: 1969-06-02
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Granted: 1971-03-23
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Expires: 1989-06-02
Abstract
Abstract A horizon sensor of the radiation balance type is described with an earth tangency mask so that the horizon sensor detectors are illuminated only by a narrow band of radiation at the horizon of the earth''s disc when the horizon sensor is positioned for correct vehicle attitude.
Inventors
- 👤 Gerald Falbel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:50
CPC Classifications
G; G01; G01S; G01S3/00; G01S3/78; G01S3/782; G01S3/783
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
95 words
In a radiation balance horizon sensor of the type comprising imaging means for imaging distant objects onto radiation detectors connected in opposition for opposed fields of view, the improvement which comprises an opaque mask restricting radiation from a radiating disc at predetermined altitude, located substantially in the focal plane of the imaging means and centrally at the mouths of the conical-type reflecting optics and permitting radiation only from a narrow annulus tangent to the horizon of the radiating disc, whereby thermal gradients on the radiating disc contribute no substantial error to the sensor''s null position.
Claim 2
Dependent Claim
95 words
In a radiation balance horizon sensor of the type comprising imaging means for imaging distant objects onto radiation detectors connected in opposition for opposed fields of view, the improvement which comprises an opaque mask restricting radiation from a radiating disc at predetermined altitude, located substantially in the focal plane of the imaging means and centrally at the mouths of the conical-type reflecting optics and permitting radiation only from a narrow annulus tangent to the horizon of the radiating disc, whereby thermal gradients on the radiating disc contribute no substantial error to the sensor''s null position.
Claim 3
Dependent Claim
37 words
A horizon sensor according to claim 1 in which the imaging means is dioptric in the form of a silicon lens and filtering means are provided to restrict radiation to wavelengths longer than about 14 Mu .
Claim 4
Dependent Claim
32 words
A horizon sensor according to claim 1 in which the detectors are mounted in conical-type reflectors and the imaging means images distant objects onto the plane of the mouths of said reflectors.
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) | 1974-03-22 | 1974-09-21 | 1975-03-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-22 | 1978-09-21 | 1979-03-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-22 | 1982-09-21 | 1983-03-23 | $7700.00 | Window Closed / Lapsed |