US3626419A
Expired / Lapsed
US
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Doppler navigation system
Assignee: International Standard Electric Corp
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Filing: 1969-09-22
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Granted: 1971-12-07
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Expires: 1989-09-22
Abstract
Abstract A first frequency signal is successively radiated from each antenna of a vertical array thereby simulating a constant velocity moving source; and second and third frequency signals are continuously transmitted from another antenna. A receiver responsive to all of the radiated signals derives therefrom the doppler shift of the first frequency signals which propagate to said receiver via a direct transmission path while distinguishing from those propagated via an indirect path. Said doppler shift is proportional to the angle of elevation from said receiver to said array.
Inventors
- 👤 Charles William Earp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:42
CPC Classifications
G; G01; G01S; G01S1/00; G01S1/02; G01S1/08; G01S1/38; G01S1/40
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
64 words
A navigation system comprising: a beacon for simulating unidirectional motion of a radiating source which radiates a first frequency signal, said unidirectional motion producing at receiving positions radiated signals having different doppler shifts corresponding to direct and indirect propagation paths; and a receiver responsive to the direct path radiated signal for deriving navigation information from the doppler frequency shift of said direct path signal.
Claim 2
Dependent Claim
64 words
A navigation system comprising: a beacon for simulating unidirectional motion of a radiating source which radiates a first frequency signal, said unidirectional motion producing at receiving positions radiated signals having different doppler shifts corresponding to direct and indirect propagation paths; and a receiver responsive to the direct path radiated signal for deriving navigation information from the doppler frequency shift of said direct path signal.
Claim 3
Dependent Claim
37 words
A navigation system, according to claim 1, wherein said beacon comprises: a vertical array of spaced aerials; a source providing said first frequency signal; and means for cyclically coupling said source to the aerials of said array.
Claim 4
Dependent Claim
34 words
A navigation system, according to claim 2, wherein said means for cyclically coupling said source to aerials of said array includes: a commutator coupled to said source; and means for controlling the commutator rate.
Claim 5
Dependent Claim
50 words
A navigation system, according to claim 1, further including: means for transmitting from a stationary source a second signal at the same frequency as that of said first frequency signal; and means for transmitting a third frequency signal at a frequency which differs from the frequency of said second signal.
Claim 6
Dependent Claim
43 words
A navigation system, according to claim 4, wherein said receiver includes: means for deriving from said second frequency signal, said third frequency signal, and said first frequency signal, the doppler shift of said first frequency signal which propagates over a direct propagation path.
Claim 7
Dependent Claim
34 words
A navigation system, according to claim 5 wherein said means for deriving the doppler shift of said first frequency signal includes a frequency discriminator, and a DC meter coupled thereto for measuring glide angles.
References Cited (Backward Citations)
US3234554A
Cited
US3290685A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-06 | 1975-06-07 | 1975-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-06 | 1979-06-07 | 1979-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-06 | 1983-06-07 | 1983-12-07 | $7700.00 | Window Closed / Lapsed |