Patent US3732013A successfully refreshed from Google Patents.
US3732013A
Expired / Lapsed
US
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Multipath laser moving target indicator
Assignee: United States Department of the Army
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Filing: 1971-04-02
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Granted: 1973-05-08
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Expires: 1991-04-02
Abstract
Abstract A moving target velocity indicator including a multipath laser which operates simultaneously as an oscillator for producing a laser beam which is directed onto both a moving target and a detector and as an amplifier of the Doppler-shifted laser beam reflected from the target. The optical return signal from the target is amplified while passing through the multipath laser system and is directed, after the final pass through the laser medium, onto the detector, This amplified signal can be combined at the detector with the transmitted signal to provide a beat signal at the frequency of the Doppler shift which can be applied to an oscilloscope display calibrated in frequency. Knowing the frequency of operation of the laser, the velocity of the target can then be calculated.
Inventors
- 👤 H Hieslmair
- 👤 J Fulton
- 👤 C Bickart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:14
CPC Classifications
G; G01; G01P; G01P3/00; G01P3/36; G01P3/366; G01S; G01S17/00; G01S17/02; G01S17/50; H; H01; H01S; H01S3/00; H01S3/02; H01S3/03; H01S3/034; H01S3/05; H01S3/08; H01S3/086
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
168 words
A moving target indicator system comprising a laser oscillator-amplifier device including a lasing medium and pumping means for supplying pump energy to said lasing medium, multi-path optical means comprising reflector means spaced at opposite ends of said lasing medium for directing a generated laser beam through said lasing medium several times along a plurality of paths, said pump energy and said multi-path optical means contributing to provide a laser gain sufficient to reach a selfoscillation threshold, said laser device including optically transparent means independent of said multi-path optical means, a detector, said multi-path optical means further directing said laser beams through said optically transparent means onto a target and onto said detector, said multi-path optical means further directing onto said detector the return laser beam from said target received by way of said optically transparent means along said plurality of paths to effect substantial amplification of said return beam, said detector producing a beat frequency signal equal to the doppler frequency shift resulting from motion of said target.
Claim 2
Dependent Claim
168 words
A moving target indicator system comprising a laser oscillator-amplifier device including a lasing medium and pumping means for supplying pump energy to said lasing medium, multi-path optical means comprising reflector means spaced at opposite ends of said lasing medium for directing a generated laser beam through said lasing medium several times along a plurality of paths, said pump energy and said multi-path optical means contributing to provide a laser gain sufficient to reach a selfoscillation threshold, said laser device including optically transparent means independent of said multi-path optical means, a detector, said multi-path optical means further directing said laser beams through said optically transparent means onto a target and onto said detector, said multi-path optical means further directing onto said detector the return laser beam from said target received by way of said optically transparent means along said plurality of paths to effect substantial amplification of said return beam, said detector producing a beat frequency signal equal to the doppler frequency shift resulting from motion of said target.
Claim 3
Dependent Claim
40 words
A moving target indicator system according to claim 1 wherein the portion of the reflector means disposed at one end of said lasing medium is adjustable to vary the number of paths of said laser beam through said lasing medium.
Claim 4
Dependent Claim
29 words
A moving target indicator system according to claim 2 wherein said adjustable portion of the reflector means comprises two semiconductor mirrors which are independently adjustable about two orthogonal axes.
Claim 5
Dependent Claim
36 words
A moving target indicator system according to claim 1 wherein said optically transparent means includes a pair of output windows through which said laser beam passes and disposed outside the region occupied by said reflector means.
Claim 6
Dependent Claim
36 words
A moving target indicator system according to claim 2 wherein said optically transparent means includes a pair of output windows through which said laser beam passes and disposed outside the region occupied by said reflector means.
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) | 1976-05-07 | 1976-11-06 | 1977-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-07 | 1980-11-06 | 1981-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-07 | 1984-11-06 | 1985-05-08 | $7700.00 | Window Closed / Lapsed |