Ralph W Patterson

US Patent:

7239135, Jul 3, 2007

Filed:

Dec 20, 2005

Appl. No.:

11/312311

Inventors:

Henry C. Abbink - Westlake Village CA, US
Edward Kanegsberg - Pacific Palisades CA, US
Ralph A. Patterson - Moorpark CA, US

Assignee:

Northrop Grumman Corporation - Los Angeles CA

International Classification:

G01V 3/00

US Classification:

324304, 324302

Abstract:

An NMR gyroscope in one example comprises a support structure affixed within an enclosure, an NMR cell affixed to the support structure, a plurality of permanent magnets disposed about the NMR cell to produce a magnetic field within the cell, and a field coil disposed proximate the cell to produce a modulated magnetic field transverse to the magnetic field produced by the permanent magnets.

US Patent:

7280218, Oct 9, 2007

Filed:

Jan 6, 2005

Appl. No.:

11/030248

Inventors:

Robert A. Mitchell - Woodland Hills CA, US
Christine E. Geosling - Calabasas CA, US
Ralph A. Patterson - Moorpark CA, US

Assignee:

Litton Systems Inc. - Woodland Hills CA

International Classification:

G01C 19/66

US Classification:

356459, 372 94

Abstract:

An apparatus and method is provided for facilitating ionization of a gas medium of a laser gyroscope. The apparatus and method employ a solid state light emitting device as a start aid for the laser gyroscope. The solid state light emitting device has a wavelength at or below a threshold wavelength based on a work function of a cathode coating material to prompt ionization of a gas medium within the laser gyroscope.

US Patent:

58568670, Jan 5, 1999

Filed:

Jul 28, 1997

Appl. No.:

8/901504

Inventors:

John P. Rahn - West Hills CA
Ralph A. Patterson - MoorPark CA

Assignee:

Litton Systems, Inc. - Woodland Hills CA

International Classification:

G01N 2100

US Classification:

356 731

Abstract:

The invention is a method and apparatus for quantitatively characterizing the pressure-induced nonreciprocity of a fiber-optic coil where the pressure-induced nonreciprocity is a property of a fiber-optic coil which pertains to the degree to which light beams, initially in phase, differ in phase as a result of traversing the fiber-optic coil in reverse directions while the fiber-optic coil is being subjected to a time-varying pressure. The method comprises the steps of applying time-varying pressure to the fiber-optic coil for a predetermined time period, measuring the phase difference of light beams traversing the fiber-optic coil in reverse directions during the predetermined time period, and obtaining a measure of the nonreciprocity of the fiber-optic coil utilizing the measured phase difference. If the time-varying pressure is specified by a first function of time, the measure of the nonreciprocity is the integral over the predetermined time period of the product of a second function of time and either (1) the phase difference of light beams traversing the fiber-optic coil in reverse directions during the predetermined time period or (2) the integral over time of the phase difference. The second function is chosen such that the measure of the nonrecipocity has a signal-to-noise ratio of at least one.

US Patent:

57423903, Apr 21, 1998

Filed:

Nov 19, 1996

Appl. No.:

8/751984

Inventors:

Amado Cordova - West Hills CA
Robert J. Hoover - Newbury Park CA
Thomas McLean - Woodland Hills CA
Ralph A. Patterson - Moorpark CA
John P. Rahn - West Hills CA

Assignee:

Litton Systems, Inc. - Woodland Hills CA

International Classification:

G01C 1964

US Classification:

356350

Abstract:

A potted sensor coil for a fiber optic gyroscope includes an inter-layer stress relief layer of lubricating material. The coil is wound into a known pattern. Various coil configurations can be realized in which a coating layer of lubricant relieves stressing at the interface between the outer jacket of the fiber and the coil potting material.

US Patent:

58185909, Oct 6, 1998

Filed:

Sep 11, 1995

Appl. No.:

8/526725

Inventors:

Ralph A. Patterson - Moorpark CA

Assignee:

Litton Systems, Inc. - Beverly Hills CA

International Classification:

G01C 1972

US Classification:

356350

Abstract:

A rotation sensor for use in a fiber optic gyroscope includes a substantially-planar disk-like coil mounting member of titanium. A would sensor coil is supported by the member in an edgewise fashion, allowing free expansion of the sensor coil in the direction orthogonal to the plane of the member to minimize thermally-induced stressing of the sensor coil. In an alternative embodiment, the free-standing coil is effectively "split"; that is, one-half is mounted to one side of the member and the remainder to the other side in such a way that the sensitive axes are coincident. Edge ramps are provided in the member for guiding the continuous optical fiber comprising the coil segments from one side of the disk-like mounting member to the other without microbends. A cylindrical inner hub includes thinned and flexible portion for contacting a mounting pedestal of stainless steel composition whereby the differential thermal expansions of the pedestal and mounting member materials will not produce misalignment of the sensor coil with respect to a predetermined input axis of rotation.

US Patent:

60409088, Mar 21, 2000

Filed:

Jul 28, 1998

Appl. No.:

9/123626

Inventors:

John P. Rahn - West Hills CA
Ralph A. Patterson - Moorpark CA
Amado Cordova - Woodland Hills CA

Assignee:

Litton Systems, Inc. - Woodland Hills CA

International Classification:

G01C 1972

US Classification:

356350

Abstract:

A method and apparatus for reducing the temperature-dependent Shupe bias of a potted gyro sensor coil pack to near-zero is provided by selectively adjusting the manner in which CCW and CW fiber leads are attached to the coil pack or the coil mount. The invention recognizes the inevitable existence of a strain differential between the CW and CCW-wound portions of a symmetrically-wound fiber coil. Leads affixed to the ends of the CW and CCW-wound halves of the coil are selectively bonded in accordance with principles for creating a counteracting temperature-dependent stress differential whereby temperature-dependent Shupe bias is substantially eliminated from the gyro output.

US Patent:

57612250, Jun 2, 1998

Filed:

May 23, 1996

Appl. No.:

8/652770

Inventors:

Bernard C. Fidric - Woodland Hills CA
Ronald James Michal - Wrightwood CA
James Ross Steele - Northridge CA
Eric Lee Goldner - Valencia CA
Ralph A. Patterson - Moorpark CA

Assignee:

Litton Systems, Inc. - Woodland Hills CA

International Classification:

H01S 330

US Classification:

372 6

Abstract:

A power boosted source of broadband optical power comprising a broadband light source, optical fiber amplifier and a relative intensity noise reduction system. The optical fiber amplifier amplifies the power level of the optical input signal to provide a power boosted source of broadband optical power out of an output port. A coupler samples a portion of the broadband optical power out of the output port as a sample portion signal. A detector and transimpedance amplifier detect the optical signal and provide a buffered signal having an instantaneous amplitude that faithfully characterizes the intensity of the sample portion signal. A bandpass amplifier amplifies the buffered signal and provides an output control signal to a light source responsive to a composite bias and control current for providing an output optical signal. The output optical signal is coupled to the input of the optical fiber amplifier to be the optical input signal to the optical fiber amplifier. The output optical signal from the ELED has a substantially constant output intensity level and smooth and bell shaped broad band spectrum with a center optical wavelength within the gain bandwidth of the optical fiber amplifier.

US Patent:

55984894, Jan 28, 1997

Filed:

Jul 27, 1994

Appl. No.:

8/281339

Inventors:

George A. Pavlath - Thousand Oaks CA
Ronald J. Michal - Wrightwood CA
Ralph A. Patterson - Canoga Park CA

Assignee:

Litton Systems, Inc. - Woodland Hills CA

International Classification:

G02B 600

US Classification:

385 12

Abstract:

A fiber optic sensing coil formed in a polarization-maintaining optical fiber has two optical fiber leads extending therefrom. A multifunction integrated optics chip linearly polarizes optical signals input to the sensing coil. Fiber optic leads formed of polarization-maintaining optical fiber extend from the multifunction integrated optics chip. The fiber optic multifunction integrated optics chip leads are arranged such that the linear polarization of optical signals output from the multifunction integrated optics chip is directed along one of the principal axes of birefringence of each of the fiber optic multifunction integrated optics chip leads. Splices are formed between corresponding the first sensing coil leads and the multifunction integrated optics chip leads. The sensing coil leads and the multifunction integrated optics chip leads are arranged such that their corresponding principal axes of birefringence are at angles of approximately 45. degree. relative to one another.