Patent US5422645A successfully refreshed from Google Patents.
US5422645A
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Delayed laser retroreflector pulse technique and system
Assignee: United States Department of the Army
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Filing: 1994-02-14
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Granted: 1995-06-06
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Expires: 2014-02-14
Abstract
Abstract A laser interrogator system and technique establishes low-observable idenication friend or foe (IFF) between two distinct positions. An interrogating laser transmits a laser pulse from a first position to a passive retroreflector fiber optic bundle located at a second position. The bundle retransmits a delayed laser retroreflector pulse. A receiver and processor at the first position processes the received retroreflected delayed laser pulse to determine a presence of a predetermined delay such that an IFF determination of the second position is achievable.
Inventors
- 👤 John E. Nettleton
- 👤 Dallas N. Barr
- 👤 Brian C. Redman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 01:24
CPC Classifications
G; G01; G01S; G01S17/00; G01S17/74
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
144 words
A laser interrogator system to establish low-observable identification friend or foe (IFF) between two distinct positions including: an interrogating laser means for generating and transmitting a laser pulse from a first position; a passive retroreflector means at a second position for receiving the laser pulse transmitted from the first position and retransmitting same back to the first position; a passive delay means coupled to the passive retroreflector means which receives the laser pulse transmitted from the first position and delays same a predetermined period of time before being retransmitted back to the first position; a receiving means at the first position for receiving the delayed retroreflected laser pulse; a processing means at the first position for processing the received retroreflected delayed laser pulse to determine the presence or absence of a predetermined delay such that an IFF determination of the second position is achievable.
Claim 2
Dependent Claim
144 words
A laser interrogator system to establish low-observable identification friend or foe (IFF) between two distinct positions including: an interrogating laser means for generating and transmitting a laser pulse from a first position; a passive retroreflector means at a second position for receiving the laser pulse transmitted from the first position and retransmitting same back to the first position; a passive delay means coupled to the passive retroreflector means which receives the laser pulse transmitted from the first position and delays same a predetermined period of time before being retransmitted back to the first position; a receiving means at the first position for receiving the delayed retroreflected laser pulse; a processing means at the first position for processing the received retroreflected delayed laser pulse to determine the presence or absence of a predetermined delay such that an IFF determination of the second position is achievable.
Claim 3
Dependent Claim
54 words
The laser integrator system of claim 1 wherein the passive delay means further includes: an optical fiber bundle core winding with first and second ends, where fiber optical path lengths of the core are matched to better than approximately one-tenth of a wavelength, and the second end of the core is made highly reflective.
Claim 4
Dependent Claim
69 words
The laser integrator system of claim 1 wherein the passive delay means further includes: an optical fiber bundle core winding with first and second ends, where the second end of the core is made highly reflective; a focusing lens means positioned between the passive retroreflector means and the first end for focusing the original pulse onto one or a few fiber ends within the first end of the core.
Claim 5
Dependent Claim
111 words
A laser interrogator technique to establish low-observable identification friend or foe between two distinct positions including the steps of: generating a laser pulse from a first position; transmitting the laser pulse from the first position to a second position; receiving the laser pulse at the second position; passively producing a time delay in the laser pulse; retransmitting the delayed laser pulse from the second position to the first position; receiving the retransmitted delayed laser pulse at the first position; processing the received retransmitted delayed laser pulse at the first position to determine the presence or absence of a predetermined delay such that an IFF determination of the second position is achievable.
Claim 6
Dependent Claim
111 words
A laser interrogator technique to establish low-observable identification friend or foe between two distinct positions including the steps of: generating a laser pulse from a first position; transmitting the laser pulse from the first position to a second position; receiving the laser pulse at the second position; passively producing a time delay in the laser pulse; retransmitting the delayed laser pulse from the second position to the first position; receiving the retransmitted delayed laser pulse at the first position; processing the received retransmitted delayed laser pulse at the first position to determine the presence or absence of a predetermined delay such that an IFF determination of the second position is achievable.
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) | 1998-06-05 | 1998-12-05 | 1999-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-06-05 | 2002-12-05 | 2003-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-06-05 | 2006-12-05 | 2007-06-06 | $7700.00 | Window Closed / Lapsed |