Patent US5847816A successfully refreshed from Google Patents.
US5847816A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fiber optic micro-doppler ladar system and operating method therefor
Assignee: McDonnell Douglas Corp
•
Filing: 1997-01-14
•
Granted: 1998-12-08
•
Expires: 2017-01-14
Abstract
Abstract A micro-doppler ladar system for identifying and analyzing a target of interest includes a transmitter and coherent receiver pair, each of which includes a fiber optic power amplifier, and a controller. Preferably, the transmitter includes a master oscillator for generating a primary laser beam, a voltage controlled oscillator (VCO) for generating a VCO signal having a predetermined, repetitive frequency pattern, a frequency shifting circuit for varying the frequency of the primary laser beam responsive to the VCO signal to thereby produce a frequency-varying primary laser signal, and the optical fiber amplifier, which amplifies the frequency-varying primary laser signal to thereby produce a transmit laser beam. In addition, the coherent receiver, which responds to backscattered light produced by the interaction of the transmit laser beam with the target of interest, includes an optical fiber pre-amplifier for amplifying the backscattered light to thereby produce an amplified return laser beam, and a phase locked loop receiving the primary laser beam and the amplified return laser beam for generating an electrical signal indicative of range, velocity and a characteristic signature of the target of interest. The transmitter and coherent receiver can be operated in a target acquisition mode of operation for determining range and velocity, and a signature acquisition mode of operation for determining a characteristic signature of the target of interest responsive to the electrical signal. A method for operating the micro-doppler ladar system is also described.
Inventors
- 👤 Mark S. Zediker
- 👤 Robert R. Rice
- 👤 Wil S. Otaguro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 20:38
CPC Classifications
G; G01; G01S; G01S7/00; G01S7/48; G01S7/481; G01S7/4818; G01P; G01P3/00; G01P3/36; G01P5/00; G01P5/26; G01S17/00; G01S17/02; G01S17/50; G01S7/4802; G01S7/4814; G01S7/4815; G01S7/491; G01S7/4912; G01S7/4917; G01S7/493
Claims Analysis
Total Claims: 48
Claim 1
Independent Claim
80 words
A micro-doppler ladar system for identifying and analyzing a target of interest, comprising: a transmitter for producing a transmit laser beam by amplification of a primary laser beam in an optical fiber amplifier; a coherent receiver responsive to backscattered light produced by interaction of said transmit laser beam with the target of interest and generating range and velocity data and a characteristic signature of the target of interest; and a controller for controlling operation of said transmitter and said receiver.
Claim 2
Dependent Claim
80 words
A micro-doppler ladar system for identifying and analyzing a target of interest, comprising: a transmitter for producing a transmit laser beam by amplification of a primary laser beam in an optical fiber amplifier; a coherent receiver responsive to backscattered light produced by interaction of said transmit laser beam with the target of interest and generating range and velocity data and a characteristic signature of the target of interest; and a controller for controlling operation of said transmitter and said receiver.
Claim 3
Dependent Claim
49 words
The micro-doppler ladar system as recited in claim 1, wherein said controller permits the micro-doppler ladar system to operate in a target acquisition mode of operation in which said range and velocity data are produced and a signature acquisition mode of operation in which said characteristic signature is generated.
Claim 4
Dependent Claim
49 words
The micro-doppler ladar system as recited in claim 2, wherein said transmit laser beam generated during said target acquisition mode of operation is a chirped frequency transmit laser beam and wherein said transmit laser beam generated during said signature acquisition mode of operation is a mono-frequency transmit laser beam.
Claim 5
Dependent Claim
17 words
The micro-doppler ladar system as recited in claim 2, wherein said characteristic signature is a vibration signature.
Claim 6
Dependent Claim
55 words
The micro-doppler ladar system as recited in claim 1, wherein said optical fiber amplifier comprises: N serially coupled rare earth doped optical fiber sections: and N pump sources, each of said pump sources operatively connected to a corresponding one of said optical fiber sections, wherein N is an integer greater than or equal to 2.
Claim 7
Dependent Claim
25 words
The micro-doppler ladar system as recited in claim 5, wherein each of said optical fiber sections comprises a Yb:Er doped single mode optical fiber core.
Claim 8
Dependent Claim
88 words
The micro-doppler ladar system as recited in claim 1, wherein said optical fiber amplifier comprises: a beam splitter receiving said primary laser beam and generating N secondary laser beams; N parallel rare earth doped optical fiber sections, each of said optical fiber sections amplifying a respective one of said N secondary laser beams to thereby produce N tertiary laser beams; and an optical combiner combining said N tertiary laser beams to thereby produce said transmit laser beam, wherein N is an integer greater than or equal to 2.
Claim 9
Dependent Claim
25 words
The micro-doppler ladar system as recited in claim 7, wherein each of said optical fiber sections comprises a Yb:Er doped single mode optical fiber core.
Claim 10
Dependent Claim
25 words
The micro-doppler ladar system as recited in claim 7, wherein said N optical fiber amplifiers are connected to said combiner by a fiber optic bundle.
Claim 11
Dependent Claim
24 words
The micro-doppler ladar system as recited in claim 1, wherein said coherent receiver further comprises an optical fiber pre-amplifier for amplifying said backscattered light.
Claim 12
Dependent Claim
118 words
A micro-doppler ladar system for identifying and analyzing a target of interest, comprising: first means for generating a primary laser beam; second means for amplifying said primary laser beam in an optical fiber amplifier means so as to generate a transmit laser beam; third means for transmitting said transmit laser beam towards the target of interest; fourth means for receiving backscattered light produced by interaction between said transmit laser beam and the target of interest and for generating an electrical signal indicative of the target of interest; fifth means for determining range and velocity responsive to said electrical signal; and sixth means for determining a characteristic signature of the target of interest different from both range and velocity.
Claim 13
Dependent Claim
118 words
A micro-doppler ladar system for identifying and analyzing a target of interest, comprising: first means for generating a primary laser beam; second means for amplifying said primary laser beam in an optical fiber amplifier means so as to generate a transmit laser beam; third means for transmitting said transmit laser beam towards the target of interest; fourth means for receiving backscattered light produced by interaction between said transmit laser beam and the target of interest and for generating an electrical signal indicative of the target of interest; fifth means for determining range and velocity responsive to said electrical signal; and sixth means for determining a characteristic signature of the target of interest different from both range and velocity.
Claim 14
Dependent Claim
65 words
The micro-doppler ladar system as recited in claim 11, wherein at least one parameter of said transmit laser beam varies so as to permit the micro-doppler ladar system to operate in a target acquisition mode of operation wherein range and velocity data are produced by said fifth means and a signature acquisition mode of operation wherein said characteristic signature is determined by said sixth means.
Claim 15
Dependent Claim
57 words
The micro-doppler ladar system as recited in claim 12, wherein said at least one parameter is frequency and wherein said transmit laser beam generated during said target acquisition mode of operation is a chirped frequency transmit laser beam and wherein transmit laser beam generated during said signature acquisition mode of operation is a mono-frequency transmit laser beam.
Claim 16
Dependent Claim
17 words
The micro-doppler ladar system as recited in claim 12, wherein said characteristic signature is a vibration signature.
Claim 17
Dependent Claim
54 words
The micro-doppler ladar system as recited in claim 11, wherein said second means comprises: N serially coupled rare earth doped optical fiber sections: and N pump sources, each of said pump sources operatively connected to a corresponding one of said optical fiber sections, wherein N is an integer greater than or equal to 2.
Claim 18
Dependent Claim
25 words
The micro-doppler ladar system as recited in claim 15, wherein each of said optical fiber sections comprises a Yb:Er doped single mode optical fiber core.
Claim 19
Dependent Claim
83 words
The micro-doppler ladar system as recited in claim 11, wherein said second means comprises: beam splitting means for receiving said primary laser beam and generating N secondary laser beams; parallel rare earth doped optical fiber section means for amplifying said N secondary laser beams in parallel to thereby produce amplified N tertiary laser beams; and optical combining means for combining said N tertiary laser beams to thereby produce said transmit laser beam, wherein N is an integer greater than or equal to 2.
Claim 20
Dependent Claim
27 words
The micro-doppler ladar system as recited in claim 17, wherein said optical fiber section means comprise N Yb:Er doped single mode optical fiber cores connected in parallel.
Claim 21
Dependent Claim
24 words
The micro-doppler ladar system as recited in claim 17, wherein an optical fiber bundle couples said optical fiber amplifier means to said combining means.
Claim 22
Dependent Claim
25 words
The micro-doppler ladar system as recited in claim 11, wherein said fourth means further comprises an optical fiber pre-amplifier means for amplifying said backscattered light.
Claim 23
Independent Claim
114 words
A method of operating a micro-doppler ladar system including a transmitter and coherent receiver for identifying and analyzing a target of interest, the method comprising the steps of: generating a primary laser beam; amplifying said primary laser beam in an optical fiber amplifier so as to generate a transmit laser beam; transmitting said transmit laser beam towards the target of interest; receiving backscattered light produced by interaction between said transmit laser beam and the target of interest and for generating an electrical signal indicative of the target of interest; determining range and velocity responsive to said electrical signal; and ascertaining a characteristic signature of the target of interest different from both range and velocity.
Claim 24
Independent Claim
114 words
A method of operating a micro-doppler ladar system including a transmitter and coherent receiver for identifying and analyzing a target of interest, the method comprising the steps of: generating a primary laser beam; amplifying said primary laser beam in an optical fiber amplifier so as to generate a transmit laser beam; transmitting said transmit laser beam towards the target of interest; receiving backscattered light produced by interaction between said transmit laser beam and the target of interest and for generating an electrical signal indicative of the target of interest; determining range and velocity responsive to said electrical signal; and ascertaining a characteristic signature of the target of interest different from both range and velocity.
Claim 25
Dependent Claim
67 words
The method for operating a micro-doppler ladar system as recited in claim 21, wherein the generating step comprises the step of generating said primary laser beam switching repeatedly between first and second frequency characteristics; wherein the determining step is performed while said primary laser beam exhibits said first frequency characteristic; and wherein the ascertaining step is performed while said primary laser beam exhibits said second frequency characteristic.
Claim 26
Dependent Claim
21 words
The method for operating a micro-doppler ladar system as recited in claim 21, wherein said characteristic signature is a vibration signature.
Claim 27
Dependent Claim
75 words
The method for operating a micro-doppler ladar system as recited in claim 21, wherein the amplifying step comprises the substeps of: splitting said primary laser beam into N secondary laser beams; amplifying said N secondary laser beams in parallel optical fiber sections to thereby produce amplified N tertiary laser beams; and combining said N tertiary laser beams to thereby produce said transmit laser beam, wherein N is an integer greater than or equal to 2.
Claim 28
Dependent Claim
31 words
The method for operating a micro-doppler ladar system as recited in claim 24, wherein said parallel optical fiber sections comprise N Yb:Er doped single mode optical fiber cores connected in parallel.
Claim 29
Dependent Claim
133 words
A transmitter for a micro-doppler ladar system adapted to identify and analyze a target of interest, comprising: a master oscillator for generating a primary laser beam; a voltage controlled oscillator (VCO) for generating a VCO signal having a predetermined, repetitive frequency pattern; a frequency shifting device for varying the frequency of said primary laser beam responsive to said VCO signal to thereby produce a frequency-varying primary laser signal; and an optical fiber amplifier for amplifying said frequency-varying primary laser signal to thereby produce a transmit laser beams wherein said optical fiber amplifier comprises: N serially coupled rare earth doped optical fiber sections: and N pump sources, each of said pump sources operatively connected to a corresponding one of said optical fiber sections, wherein N is an integer greater than or equal to 2.
Claim 30
Dependent Claim
133 words
A transmitter for a micro-doppler ladar system adapted to identify and analyze a target of interest, comprising: a master oscillator for generating a primary laser beam; a voltage controlled oscillator (VCO) for generating a VCO signal having a predetermined, repetitive frequency pattern; a frequency shifting device for varying the frequency of said primary laser beam responsive to said VCO signal to thereby produce a frequency-varying primary laser signal; and an optical fiber amplifier for amplifying said frequency-varying primary laser signal to thereby produce a transmit laser beams wherein said optical fiber amplifier comprises: N serially coupled rare earth doped optical fiber sections: and N pump sources, each of said pump sources operatively connected to a corresponding one of said optical fiber sections, wherein N is an integer greater than or equal to 2.
Claim 31
Dependent Claim
28 words
The transmitter for the micro-doppler ladar system as recited in claim 26, wherein each of said optical fiber sections comprises a Yb:Er doped single mode optical fiber core.
Claim 32
Dependent Claim
167 words
A transmitter for a micro-doppler ladar system adapted to identify and analyze a target of interest, comprising: a master oscillator for generating a primary laser beam; a voltage controlled oscillator (VCO) for generating a VCO signal having a predetermined, repetitive frequency pattern; a frequency shifting device for varying the frequency of said primary laser beam responsive to said VCO signal to thereby produce a frequency-varying primary laser signal; and an optical fiber amplifier for amplifying said frequency-varying primary laser signal to thereby produce a transmit laser beam, wherein said optical fiber amplifier comprises: a beam splitter receiving said frequency-varying primary laser beam and generating N secondary laser beams; N parallel rare earth doped optical fiber sections, each of said optical fiber sections amplifying a respective one of said N secondary laser beams to thereby produce N tertiary laser beams; and an optical combiner combining said N tertiary laser beams to thereby produce said transmit laser beam, wherein N is an integer greater than or equal to 2.
Claim 33
Dependent Claim
167 words
A transmitter for a micro-doppler ladar system adapted to identify and analyze a target of interest, comprising: a master oscillator for generating a primary laser beam; a voltage controlled oscillator (VCO) for generating a VCO signal having a predetermined, repetitive frequency pattern; a frequency shifting device for varying the frequency of said primary laser beam responsive to said VCO signal to thereby produce a frequency-varying primary laser signal; and an optical fiber amplifier for amplifying said frequency-varying primary laser signal to thereby produce a transmit laser beam, wherein said optical fiber amplifier comprises: a beam splitter receiving said frequency-varying primary laser beam and generating N secondary laser beams; N parallel rare earth doped optical fiber sections, each of said optical fiber sections amplifying a respective one of said N secondary laser beams to thereby produce N tertiary laser beams; and an optical combiner combining said N tertiary laser beams to thereby produce said transmit laser beam, wherein N is an integer greater than or equal to 2.
Claim 34
Dependent Claim
28 words
The transmitter for the micro-doppler ladar system as recited in claim 28, wherein each of said optical fiber sections comprises a Yb:Er doped single mode optical fiber core.
Claim 35
Dependent Claim
28 words
The transmitter for the micro-doppler ladar system as recited in claim 28, wherein said N optical fiber amplifiers are connected to said combiner by a fiber optic bundle.
Claim 36
Dependent Claim
65 words
The transmitter for the micro-doppler ladar system as recited in claim 28, wherein each of said N rare earth doped optical fiber sections further comprises: M serially coupled rare earth doped optical fiber sections: and M pump sources, each of said pump sources operatively connected to a corresponding one of said optical fiber sections, wherein M is an integer greater than or equal to 2.
Claim 37
Dependent Claim
247 words
A micro-doppler ladar system for identifying and analyzing a target of interest, comprising: a transmitter for producing a transmit laser beam by amplification of a primary laser beam in an optical fiber amplifier, said amplifier including: a master oscillator for generating the primary laser beam; a voltage controlled oscillator (VCO) for generating a VCO signal having a predetermined, repetitive frequency pattern; a frequency shifting device for varying the frequency of said primary laser beam responsive to said VCO signal to thereby produce a frequency-varying primary laser signal; and an optical fiber amplifier for amplifying said frequency-varying primary laser signal to thereby produce a transmit laser beam; a coherent receiver responsive to backscattered light produced by interaction of said transmit laser beam with the target of interest and generating range and velocity data and a characteristic signature of the target of interest, said coherent receiver including: an optical fiber pre-amplifier for amplifying said backscattered light to thereby produce an amplified return laser beam; a phase locked loop receiving said primary laser beam and said amplified return laser beam for generating an electrical signal indicative of range, velocity and a characteristic signature of the target of interest; and a controller for controlling operation of said transmitter and said receiver in a target acquisition mode of operation in which said range and velocity data are easily extracted from said electrical signals and a signature acquisition mode of operation in which said characteristic signature is easily extracted from said electrical signal.
Claim 38
Dependent Claim
247 words
A micro-doppler ladar system for identifying and analyzing a target of interest, comprising: a transmitter for producing a transmit laser beam by amplification of a primary laser beam in an optical fiber amplifier, said amplifier including: a master oscillator for generating the primary laser beam; a voltage controlled oscillator (VCO) for generating a VCO signal having a predetermined, repetitive frequency pattern; a frequency shifting device for varying the frequency of said primary laser beam responsive to said VCO signal to thereby produce a frequency-varying primary laser signal; and an optical fiber amplifier for amplifying said frequency-varying primary laser signal to thereby produce a transmit laser beam; a coherent receiver responsive to backscattered light produced by interaction of said transmit laser beam with the target of interest and generating range and velocity data and a characteristic signature of the target of interest, said coherent receiver including: an optical fiber pre-amplifier for amplifying said backscattered light to thereby produce an amplified return laser beam; a phase locked loop receiving said primary laser beam and said amplified return laser beam for generating an electrical signal indicative of range, velocity and a characteristic signature of the target of interest; and a controller for controlling operation of said transmitter and said receiver in a target acquisition mode of operation in which said range and velocity data are easily extracted from said electrical signals and a signature acquisition mode of operation in which said characteristic signature is easily extracted from said electrical signal.
Claim 39
Dependent Claim
55 words
The micro-doppler ladar system as recited in claim 32, wherein said optical fiber amplifier comprises: N serially coupled rare earth doped optical fiber sections: and N pump sources, each of said pump sources operatively connected to a corresponding one of said optical fiber sections, wherein N is an integer greater than or equal to 2.
Claim 40
Dependent Claim
25 words
The micro-doppler ladar system as recited in claim 33, wherein each of said optical fiber sections comprises a Yb:Er doped single mode optical fiber core.
Claim 41
Dependent Claim
89 words
The micro-doppler ladar system as recited in claim 32, wherein said optical fiber amplifier comprises: a beam splitter receiving said frequency-varying primary laser beam and generating N secondary laser beams; N parallel rare earth doped optical fiber sections, each of said optical fiber sections amplifying a respective one of said N secondary laser beams to thereby produce N tertiary laser beams; and an optical combiner combining said N tertiary laser beams to thereby produce said transmit laser beam, wherein N is an integer greater than or equal to 2.
Claim 42
Dependent Claim
25 words
The micro-doppler ladar system as recited in claim 35, wherein each of said optical fiber sections comprises a Yb:Er doped single mode optical fiber core.
Claim 43
Dependent Claim
26 words
The micro-doppler ladar system as recited in claim 35, wherein said N optical fiber amplifiers are connected to said optical combiner by a fiber optic bundle.
Claim 44
Dependent Claim
62 words
The micro-doppler ladar system as recited in claim 35, wherein each of said N rare earth doped optical fiber sections further comprises: M serially coupled rare earth doped optical fiber sections: and M pump sources, each of said pump sources operatively connected to a corresponding one of said optical fiber sections, wherein M is an integer greater than or equal to 2.
Claim 45
Dependent Claim
161 words
The micro-doppler ladar system as recited in claim 32, wherein said optical fiber amplifier comprises: a beam splitter receiving said frequency-varying primary laser beam and generating N secondary laser beams; N phase modulators responsive to N phase error signals for controlling the phase of each of said n secondary laser beams so as to produce N phase modulated secondary laser beams, respectively; N parallel rare earth doped optical fiber sections, each of said optical fiber sections amplifying a respective one of said N phase modulated secondary laser beams to thereby produce N tertiary laser beams; an optical combiner combining said N tertiary laser beams to thereby produce said transmit laser beam; circuitry for detecting phase errors in said N tertiary laser beams and for generating respective ones of said N phase error signals, wherein N is an integer greater than or equal to 2, and wherein said N tertiary laser beams arrive at said optical combiner with a predetermined phase profile.
Claim 46
Dependent Claim
25 words
The micro-doppler ladar system as recited in claim 39, wherein each of said optical fiber sections comprises a Yb:Er doped single mode optical fiber core.
Claim 47
Dependent Claim
26 words
The micro-doppler ladar system as recited in claim 39, wherein said N optical fiber amplifiers are connected to said optical combiner by a fiber optic bundle.
Claim 48
Dependent Claim
84 words
The micro-doppler ladar system as recited in claim 39, wherein each of said N rare earth doped optical fiber sections further comprises: M serially coupled rare earth doped optical fiber lengths for generating a respective one of said N tertiary laser beams: and M pump sources, each of said pump sources operatively connected to a corresponding one of said optical fiber lengths for pumping an associated one of said M optical fiber lengths, wherein M is an integer greater than or equal to 2.
References Cited (Backward Citations)
US4757268A
Cited
US5267011A
Cited
US5434662A
Cited
US5621514A
Cited
US5530582A
Cited
US5530582C1
Cited
US5696782A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-12-07 | 2002-06-08 | 2002-12-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-12-07 | 2006-06-08 | 2006-12-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-12-07 | 2010-06-08 | 2010-12-08 | $7700.00 | Window Closed / Lapsed |