US3728734A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of resolving multiple sweep ambiguities encountered in high resolution graphic recorders and the like
Assignee: United States Department of the Navy
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Filing: 1971-04-23
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Granted: 1973-04-17
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Expires: 1991-04-23
Abstract
Abstract A high resolution recording system is one in which the signal transit time significantly exceeds the recorder sweep so that N sweeps occur before the first recorded return. Thus, it becomes a problem to determine which sweep from time zero is represented by a recorded mark. This problem is referred to as the multiple sweep ambiguity. To resolve the ambiguity, the recorder sweep speed (stylus velocity) can be varied a small amount, such as 5 percent, and a series of marks made at this increased sweep speed. These marks will be offset a distance equal to N/20 of a sweep where N is the unknown number of elapsed sweeps. A measurement of the offset distance provides a permanent index representative of the total elapsed time.
Inventors
- 👤 D Boegeman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 22:40
CPC Classifications
G; G01; G01S; G01S7/00; G01S7/52; G01S7/56; G01S7/60
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
120 words
A method of resolving multiple sweep ambiguities encountered in recording devices having a constant sweep travel time for producing a consecutive series of marks each representing the travel time of a periodically-recurring signal comprising: operating said recording device at said constant speed to produce a series of consecutive marks, said series representing a data index (D) for said periodically-recurring signal, momentarily varying said constant sweep time a known amount to produce another series of consecutive marks representing an offset data index (D'') for said signal, and measuring the distance between D and D'', said distance representing the number of sweeps at said constant velocity required to produce a mark for said signal whereby said multiple sweep ambiguity can be resolved.
Claim 2
Independent Claim
120 words
A method of resolving multiple sweep ambiguities encountered in recording devices having a constant sweep travel time for producing a consecutive series of marks each representing the travel time of a periodically-recurring signal comprising: operating said recording device at said constant speed to produce a series of consecutive marks, said series representing a data index (D) for said periodically-recurring signal, momentarily varying said constant sweep time a known amount to produce another series of consecutive marks representing an offset data index (D'') for said signal, and measuring the distance between D and D'', said distance representing the number of sweeps at said constant velocity required to produce a mark for said signal whereby said multiple sweep ambiguity can be resolved.
Claim 3
Independent Claim
159 words
A method of resolving multiple sweep ambiguities encountered in recorders of a type having a constant velocity sweep arm for marking on a recording sheet the travel time of a relatively long periodically-recurring signal comprising: driving said arm relative to said sheet at a constant velocity a sufficient period of time to provide a series of marks representing an original index (D) and formed by a plurality of said recurrent signals, varying the velocity of said arm a known amount, driving said arm relative to said sheet at said varied velocity a sufficient period of time to provide another series of marks representing an offset data index (D'') also formed by a plurality of recurrent signals, and measuring the distance between offset data index (D'') and original data index (D), said (D'' -D) distance being representative of the number of sweeps required for each recurrence of said relatively long signal when said arm is driven at said constant velocity.
Claim 4
Independent Claim
159 words
A method of resolving multiple sweep ambiguities encountered in recorders of a type having a constant velocity sweep arm for marking on a recording sheet the travel time of a relatively long periodically-recurring signal comprising: driving said arm relative to said sheet at a constant velocity a sufficient period of time to provide a series of marks representing an original index (D) and formed by a plurality of said recurrent signals, varying the velocity of said arm a known amount, driving said arm relative to said sheet at said varied velocity a sufficient period of time to provide another series of marks representing an offset data index (D'') also formed by a plurality of recurrent signals, and measuring the distance between offset data index (D'') and original data index (D), said (D'' -D) distance being representative of the number of sweeps required for each recurrence of said relatively long signal when said arm is driven at said constant velocity.
Claim 5
Dependent Claim
26 words
The method of claim 2 further including the step of returning said sweep arm to its normal velocity after said offset data index has been produced.
Claim 6
Dependent Claim
49 words
The method of claim 2 applied to high resolution sonar ranging recorders having a variable speed stylus arm synchronized with a sonar transmitter to produce a mark representative of the return of each signal generated by the transmitter, said periodically-recurring signal being the return echo of the transmitter-generated signal.
Claim 7
Dependent Claim
24 words
The method of claim 4 further including the initial step of adjusting the sweep velocity of the stylus for a desired degree of resolution.
Claim 8
Dependent Claim
21 words
The method of claim 4 wherein said sweep velocity is varied an amount equal to 5 percent of said constant velocity.
References Cited (Backward Citations)
US2982940A
Cited
US2941183A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-16 | 1976-10-16 | 1977-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-16 | 1980-10-16 | 1981-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-16 | 1984-10-16 | 1985-04-17 | $7700.00 | Window Closed / Lapsed |