US3873983A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radio navigation beacon
Assignee: International Standard Electric Corp
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Filing: 1972-08-14
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Granted: 1975-03-25
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Expires: 1992-08-14
Abstract
Abstract A Doppler Navigation system which includes a surface based commutated array on a platform to provide air derived angle information, particularly for aircraft landing approach guidance. The program of array commutation is frequency off-set with respect to a reference antenna and this offset is used in the air derivation of angle data. A gyro or other source of platform pitch or yaw provides a signal which is used to shift the socalled offset to compensate measurement errors due to platform motion.
Inventors
- 👤 Peter Sothcott
- 👤 Stanley B Marsh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:54
CPC Classifications
G; G01; G01S; G01S1/00; G01S1/02; G01S1/08; G01S1/38; G01S1/40
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
168 words
In a radio navigation approach beacon system mounted on an astable platform for radiating energy from an array commutated to simulate constant velocity linear motion of a radiating source of radio frequency energy whereby an apparent Doppler modulated signal is received by a remote station, the combination comprising: first means for radiating a radio frequency reference signal; second means providing a radio frequency excitation signal to said commutated array at a frequency offset from the frequency of said reference signal, thereby to radiate which said remote station can extract a beat frequency signal which varies with the cosine of the angular approach path to provide approach angle data; third means for sensing variations in the orientation of said astable platform to generate an error signal representative of said variations; and fourth means connected to said third means for controlling the frequency offset of said array excitation signal to compensate for angular movement of said platform in the approach plane corresponding to the plane containing said approach angle data.
Claim 2
Dependent Claim
168 words
In a radio navigation approach beacon system mounted on an astable platform for radiating energy from an array commutated to simulate constant velocity linear motion of a radiating source of radio frequency energy whereby an apparent Doppler modulated signal is received by a remote station, the combination comprising: first means for radiating a radio frequency reference signal; second means providing a radio frequency excitation signal to said commutated array at a frequency offset from the frequency of said reference signal, thereby to radiate which said remote station can extract a beat frequency signal which varies with the cosine of the angular approach path to provide approach angle data; third means for sensing variations in the orientation of said astable platform to generate an error signal representative of said variations; and fourth means connected to said third means for controlling the frequency offset of said array excitation signal to compensate for angular movement of said platform in the approach plane corresponding to the plane containing said approach angle data.
Claim 3
Dependent Claim
47 words
Apparatus according to claim 1 in which said angular movement is pitch, as understood in connection with ships, said commutated array is generally vertically oriented, said orientation variations sensed by said third means are pitch movements, and said approach plane of said beacon is the elevation plane.
Claim 4
Dependent Claim
47 words
Apparatus according to claim 1 in which said angular movement is yaw, as understood in connection with ships, said commutated array is generally horizontally oriented, said orientation variations sensed by said third means are yaw movements including steering errors, and said approach plane is the bearing plane.
Claim 5
Dependent Claim
226 words
In a radio navigation approach beacon system mounted on an astable platform for radiating energy from an array commutated to simulate constant velocity linear motion of a radiating source of radio frequency energy wherebY an apparent Doppler modulated signal is received by a remote station, the combination comprising: first means for radiating a radio frequency reference signal; second means providing a radio frequency excitation signal to said commutated array at a frequency offset from the frequency of said reference signal, thereby to radiate which said remote station can extract a beat frequency signal which varies with the cosine of the angular approach path to provide approach angle data; third means for sensing variations in the orientation of said astable platform and for generating a bipolar error signal corresponding to pitch angles on respective sides of a reference plane; and fourth means connected to said third means for controlling said frequency offset of said array excitation signal to compensate for angular movement of said platform in the approach plane of said beacon, said fourth means being operative to increase said frequency offset corresponding to said third means signals representative of pitch angles in one sense with respect to said reference plane and to decrease said frequency offset corresponding to said third means signals representative of pitch angles in the other sense with respect to said reference plane.
Claim 6
Dependent Claim
226 words
In a radio navigation approach beacon system mounted on an astable platform for radiating energy from an array commutated to simulate constant velocity linear motion of a radiating source of radio frequency energy wherebY an apparent Doppler modulated signal is received by a remote station, the combination comprising: first means for radiating a radio frequency reference signal; second means providing a radio frequency excitation signal to said commutated array at a frequency offset from the frequency of said reference signal, thereby to radiate which said remote station can extract a beat frequency signal which varies with the cosine of the angular approach path to provide approach angle data; third means for sensing variations in the orientation of said astable platform and for generating a bipolar error signal corresponding to pitch angles on respective sides of a reference plane; and fourth means connected to said third means for controlling said frequency offset of said array excitation signal to compensate for angular movement of said platform in the approach plane of said beacon, said fourth means being operative to increase said frequency offset corresponding to said third means signals representative of pitch angles in one sense with respect to said reference plane and to decrease said frequency offset corresponding to said third means signals representative of pitch angles in the other sense with respect to said reference plane.
Claim 7
Dependent Claim
16 words
Apparatus according to claim 4 in which said reference plane is defined as the horizontal plane.
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) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |