US3573828A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Synchronization indicator
Assignee: Northrop Grumman Corp
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Filing: 1969-04-15
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Granted: 1971-04-06
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Expires: 1989-04-15
Abstract
Abstract In order to synchronize a locally generated timing pattern in a receiver with a transmitted timing pattern as received, the strongest signal in the received pattern is separated from all others and transformed into a first pulse having the same timing as that strongest signal. At the same time, the pulse of the generated pattern which corresponds to the strongest station at the present receiver location, as determined by the operator''s knowledge, is compared in time relation to the first pulse, and the generated pattern is advanced or retarded until exact synchronism of these two is achieved, as indicated by the reading of a meter in the output of a differential amplifier.
Inventors
- 👤 Opie D Hawley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:52
CPC Classifications
G; G01; G01S; G01S1/00; G01S1/02; G01S1/08; G01S1/20; G01S1/30; G01S1/308
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
139 words
In a receiver, the method of indicating synchronism or lack of synchronism of a locally generated timing pattern with a transmitted timing pattern of the same repetition rate, the transmitted timing pattern having a series of spaced radio frequency bursts from a corresponding number of transmitter stations of known relative strength at said receiver, the generated timing pattern having a series of substantially square pulses of the same respective width and spacing as said transmitted burst, which comprises: isolating the strongest received burst in said transmitted pattern; selecting the one pulse in said generated pattern corresponding to the station known to have the greatest received signal strength at said receiver; comparing said strongest burst and said selected pulse in relation to time of occurrence; and indicating to an operator the state of coincidence of said burst and said pulse.
Claim 2
Dependent Claim
139 words
In a receiver, the method of indicating synchronism or lack of synchronism of a locally generated timing pattern with a transmitted timing pattern of the same repetition rate, the transmitted timing pattern having a series of spaced radio frequency bursts from a corresponding number of transmitter stations of known relative strength at said receiver, the generated timing pattern having a series of substantially square pulses of the same respective width and spacing as said transmitted burst, which comprises: isolating the strongest received burst in said transmitted pattern; selecting the one pulse in said generated pattern corresponding to the station known to have the greatest received signal strength at said receiver; comparing said strongest burst and said selected pulse in relation to time of occurrence; and indicating to an operator the state of coincidence of said burst and said pulse.
Claim 3
Dependent Claim
19 words
Method in accordance with claim 1 including advancing or retarding said generated timing pattern as indicated to achieve coincidence.
Claim 4
Dependent Claim
124 words
In a navigation receiver system having a locally generated timing pattern to be synchronized with a transmitter timing pattern as received, the transmitter timing pattern having a standard repeated series of signal bursts of known time duration and spacing, adjacent bursts being from different known transmitting stations, and the generated timing pattern having a repetitive series of pulses corresponding respectively to said signal bursts in width and spacing; a synchronism indicator comprising: means for isolating the strongest received signal burst from said transmitter pattern; means for selecting any of said generated timing pattern; means for comparing said strongest signal burst and said selected generated pulse in real time relation; and means for indicating synchronism or lack of synchronism of said burst and said pulse.
Claim 5
Dependent Claim
124 words
In a navigation receiver system having a locally generated timing pattern to be synchronized with a transmitter timing pattern as received, the transmitter timing pattern having a standard repeated series of signal bursts of known time duration and spacing, adjacent bursts being from different known transmitting stations, and the generated timing pattern having a repetitive series of pulses corresponding respectively to said signal bursts in width and spacing; a synchronism indicator comprising: means for isolating the strongest received signal burst from said transmitter pattern; means for selecting any of said generated timing pattern; means for comparing said strongest signal burst and said selected generated pulse in real time relation; and means for indicating synchronism or lack of synchronism of said burst and said pulse.
Claim 6
Dependent Claim
71 words
Apparatus in accordance with claim 3 wherein said isolating means comprises: an envelope detector connected to the IF strip of said receiver system; a DC restorer connected to the output of said envelope detector; and a level detector connected to the output of said DC restorer whereby the output of said level detector is a single pulse signal corresponding in width and time to each occurrence of said strongest received burst.
Claim 7
Dependent Claim
46 words
Apparatus in accordance with claim 3 wherein said selecting means comprises manually operated selector switch means connected to suitable generator means in said receiver system having separate terminals where a pulse appears on each terminal corresponding only to respective station pulses in said generated timing pattern.
Claim 8
Dependent Claim
49 words
Apparatus in accordance with claim 3 wherein said comparing means comprises a difference amplifier having said strongest burst and said selected pulse fed to the two respective inputs thereof, the output of said difference amplifier being a zero signal when said strongest pulse and said selected pulse are coincident.
Claim 9
Dependent Claim
19 words
Apparatus in accordance with claim 6 including a zero center DC meter connected to the output of said amplifier.
References Cited (Backward Citations)
US3380056A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-04-05 | 1974-10-05 | 1975-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-05 | 1978-10-05 | 1979-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-05 | 1982-10-05 | 1983-04-06 | $7700.00 | Window Closed / Lapsed |