ROBERT ANTHONY MITCHELL
Pilots at Erwin St, Woodland Hills, CA

License number
California A1311066
Category
Airmen
Type
Authorized Aircraft Instructor
Address
Address
21601 Erwin St APT 240, Woodland Hills, CA 91367

Professional information

Robert Mitchell Photo 1

Means And Method For Active Dispersion Equalization Of A Multioscillator Ring Laser Gyroscope

US Patent:
5786895, Jul 28, 1998
Filed:
Mar 11, 1996
Appl. No.:
8/613335
Inventors:
Robert A. Mitchell - Woodland Hills CA
Tae Whan Hahn - Chatsworth CA
Assignee:
Litton Systems, Inc. - Woodland Hills CA
International Classification:
G01C 1966
US Classification:
356350
Abstract:
Based upon the equation, BIAS. sub. G. alpha. (I. sub. DE -I. sub. COIL). multidot. (V. sub. DE -V. sub. OFF), where BIAS. sub. G is the bias of a multi-oscillator ring-laser gyroscope (14) as induced by gain medium dispersion effects, I. sub. DE is the proper operating coil current, I. sub. COIL is the actual coil current, V. sub. DE is the proper path length control operating voltage and V. sub. OFF is the actual offset voltage, V. sub. DE is matched by path length control offset voltage and/or I. sub. DE is matched by proper coil current, to produce a zero induced BIAS. sub. G. Matching, through dispersion equalization (DE), is effected by use of clockwise (C) and anticlockwise (A) (or counterclockwise) beams traversing paths with a frame (12). The beams are directed to photodetectors (52, 54) and power meters (56, 58).


Robert Mitchell Photo 2

Simplified Dispersion Equalization Field Coil Design For A Multioscillator Ring Laser Gyroscope

US Patent:
5488622, Jan 30, 1996
Filed:
Jul 29, 1994
Appl. No.:
8/283393
Inventors:
Robert A. Mitchell - Woodland Hills CA
Assignee:
Litton Systems, Inc. - Woodland Hills CA
International Classification:
H01S 300
US Classification:
372 33
Abstract:
At least one coil (32) is located on an exterior side face (30) of a frame (12) of a ring laser gyroscope (10) such that a significant component of the magnetic field generated by the coil is colinear with the plasma discharge of the gyroscope, and by which dispersion equalization of the gyroscope can be effected. The coil may be supported by a magnetically permeable annular bobbin (40), which is set about a mirror (26) on side face (30) and which may be partly set within grooves in the side face, to reduce the current necessary to effect dispersion equalization and to provide shielding of the mirror from the effects of tangential and transverse fields, and to increase the shielding effects for the mirror, both from Faraday rotator magnets (16) and from external magnetic fields. For those mirrors where no coils are present, the annular bobbins are used solely for their shielding properties.


Robert Mitchell Photo 3

Plasma Shunting Apparatus And Method For Ring Laser Gyroscope

US Patent:
7535575, May 19, 2009
Filed:
Jun 5, 2007
Appl. No.:
11/810443
Inventors:
Robert Mitchell - Woodland Hills CA, US
Shane Sammon - Reseda CA, US
Carl Bathelt, Jr. - Simi Valley CA, US
Assignee:
Litton Systems, Inc. - Woodland Hills CA
International Classification:
G01C 19/64, G01C 19/66
US Classification:
356459, 356469
Abstract:
A ring laser gyroscope includes a first plasma shunt arranged to prevent the plasma from contacting a first mirror in the gain region and a second plasma shunt arranged to prevent the plasma from contacting a second mirror in the gain region. The first and second plasma shunts may comprise electrical conductors located in the respective mirror wells and arranged such that contact between the plasma and the electrical conductors quenches the plasma in the mirror wells and produces electrical currents that travels across the mirror wells. The electrical conductors may be formed as metallized strips arranged to extend across the mirror wells, or they may be formed from metal wires. The plasma shunts may alternatively comprise diversion passages formed in the frame and arranged such that the plasma fills the diversion passages and bypasses the mirrors.


Robert Mitchell Photo 4

Ring Laser Gyroscope Output Optics Detection System

US Patent:
5116132, May 26, 1992
Filed:
Jan 12, 1990
Appl. No.:
7/464164
Inventors:
Robert A. Mitchell - Woodland Hills CA
David B. Hall - La Crescenta CA
Kenneth W. Shafer - Thousand Oaks CA
Assignee:
Litton Systems, Inc. - Woodland Hills CA
International Classification:
G01B 902
US Classification:
356350
Abstract:
A ring laser gyroscope output optics detection system, including a rotational sensing system and cavity length control system for a multioscillator ring laser gyroscope, is disclosed herein that can operate with a simple upright symmetric optics mechanism, where the required signal separation is performed fully electronically. In a preferred embodiment, signal separation circuitry is provided which performs a 90. degree. or. pi. /2 radians phase shift to one of a set of heterodyned signals in order to extract the sagnac effect modulated Faraday frequency signals W. sub. A and W. sub. B. In order to deal with the inherent problems of crosstalk present in a Faraday biased system, alternative signal separation schemes suggest the use of a 45. degree. or. pi. /4 radians phase shift, as well as a 60. degree. or. pi. /3 radians phase shift.


Robert Mitchell Photo 5

Adaptively Aligned Optical Correlator And Method

US Patent:
6330361, Dec 11, 2001
Filed:
Mar 16, 1999
Appl. No.:
9/268789
Inventors:
Robert A. Mitchell - Woodland Hills CA
Stuart A. Mills - West Hills CA
James Ryan - Van Nuys CA
Assignee:
Litton Systems, Inc. - Agoura Hills CA
International Classification:
G06K 900, G06K 976, G06K 974, G06K 112, G06K 2746
US Classification:
382211
Abstract:
An improved optical correlator using a coherent light beam employs a method of adaptive alignment. A test pattern modulates an input spatial light modulator. The modulated beam propagates through passive transforming optical elements to a filter spatial light modulator, which is simultaneously modulated with an independently transformed frequency domain reference. The resulting correlation or coincidence of the optically transformed pattern with the independently transformed reference is processed to yield a feedback signal indicative of any optical misalignment of the optical correlator. The feedback signal drives a beam deflector to compensate by adjusting the path of the coherent beam, thereby improving and maintaining optical alignment of the correlator.


Robert Mitchell Photo 6

Apparatus And Method To Facilitate Laser Gyroscope Ionization

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.