US3841755A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Doppler effect telemeter including frequency shifting
Assignee: Alcatel Lucent SAS
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Filing: 1972-12-04
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Granted: 1974-10-15
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Expires: 1992-12-04
Abstract
Abstract A doppler effect and modulated frequency telemeter in which the frequency of the signal sent toward a target is modulated with symmetrical saw-tooth waves. The time interval between two successive passes through a fixed reference frequency of the shifted frequency of the signal sent back by the target is used to develop an interval signal which is proportional to the relative radial speed of the target.
Inventors
- 👤 H Debart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 17:18
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/02; G01S13/50; G01S13/58; G01S13/583; G01S13/584; G01S17/00; G01S17/02; G01S17/06; G01S17/08; G01S17/32; G01S17/34; G01S17/50
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
278 words
A DOPPLER effect and modulated frequency telemeter comprising: a. scanning means for causing an alternate scanning signal having an adjustable frequency to be propagated towards a target capable of reflecting that scanning signal, by sending back, towards the telemeter, a frequency shifted response signal resulting from reflection of that scanning signal; b. modulation generator means for controlling said scanning means By a modulation signal so as to create a variation in the frequency of the said scanning signal according to a predetermined variation law as a function of time; c. receiving means, sensitive to the frequency shift between said response signal and said scanning signal, for supplying a speed indication signal proportional to that shift; d. wherein said receiving means comprises a frequency comparator supplying a pass signal each time the frequency of the said response signal is equal to a predetermined reference frequency, the said predetermined frequency variation law being a periodic and alternate succession of ramps of two different types, that is, of ramps of two different slopes making the frequency of the said scanning signal vary between a low frequency and a high frequency, said reference frequency being chosen such that the time interval between two successive passes of the frequency of said scanning signal through that reference frequency be equal to the half-cycle of that succession of ramps; e. time comparator means, receiving said pass signals for supplying at least one interval signal representing the value of a pass interval, that is, of a time interval between two successive pass signals; and f. speed indicator means for receiving said interval signal and supplying a speed indication dependent on the value of that interval signal.
Claim 2
Dependent Claim
278 words
A DOPPLER effect and modulated frequency telemeter comprising: a. scanning means for causing an alternate scanning signal having an adjustable frequency to be propagated towards a target capable of reflecting that scanning signal, by sending back, towards the telemeter, a frequency shifted response signal resulting from reflection of that scanning signal; b. modulation generator means for controlling said scanning means By a modulation signal so as to create a variation in the frequency of the said scanning signal according to a predetermined variation law as a function of time; c. receiving means, sensitive to the frequency shift between said response signal and said scanning signal, for supplying a speed indication signal proportional to that shift; d. wherein said receiving means comprises a frequency comparator supplying a pass signal each time the frequency of the said response signal is equal to a predetermined reference frequency, the said predetermined frequency variation law being a periodic and alternate succession of ramps of two different types, that is, of ramps of two different slopes making the frequency of the said scanning signal vary between a low frequency and a high frequency, said reference frequency being chosen such that the time interval between two successive passes of the frequency of said scanning signal through that reference frequency be equal to the half-cycle of that succession of ramps; e. time comparator means, receiving said pass signals for supplying at least one interval signal representing the value of a pass interval, that is, of a time interval between two successive pass signals; and f. speed indicator means for receiving said interval signal and supplying a speed indication dependent on the value of that interval signal.
Claim 3
Dependent Claim
43 words
Telemeter according to claim 1, wherein said scanning means comprises a laser transmitter whose light beam crosses through a BRAGG effect frequency modulator provided with a piezo-electric transducer supplied by an electronic oscillator having an adjustable frequency controlled by the said modulation generator.
Claim 4
Dependent Claim
77 words
Telemeter according to claim 1, wherein said time comparator means supplies at least two interval signals corresponding, the one to the long interval, that is, to a said pass interval longer than the said half-cycle, and the other to a short interval, that is, to a said pass interval shorter than the said half-cycle, the said speed indicator means supplying a speed indication proportional to the difference between the said long interval and the said short interval.
Claim 5
Dependent Claim
45 words
Telemeter according to claim 3, wherein the ramps of the said two types are linear ramps alternately increasing and decreasing in a same duration between the said high and low frequencies, the said reference frequency being the average frequency between these high and low frequencies.
Claim 6
Dependent Claim
23 words
Telemeter according to claim 1, further including means for replacing said reference frequency by a predetermined auxiliary frequency different from that reference frequency.
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) | 1977-10-14 | 1978-04-15 | 1978-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-14 | 1982-04-15 | 1982-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-14 | 1986-04-15 | 1986-10-15 | $7700.00 | Window Closed / Lapsed |