Patents by Inventor Gregor John McDonald
Gregor John McDonald has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 8451433Abstract: Range-finding apparatus comprises a source of pulsed radiation of variable repetition rate and a beam-splitter for dividing the pulsed radiation into two portions which are directed respectively to a local retro-reflector and to a retro-reflector co-located with a remote target the range of which is to be determined. The source, beam-splitter and retro-reflectors are arranged in the form of Michelson interferometer together with a detector. The repetition rate of the source is tuned to frequencies f such that round-trip distance to the remote target is mc/f where m is an integer, this condition being detected by observing a heterodyne signal at the detector. Two such frequencies enable range to be determined. The precision with which range is determined may be increased by carrying out interferometry using the two portions. The accuracy of the method does not depend on absolute range (as with triangulation) and is not limited by the speed of timing electronics, as is the case for time-of-flight techniques.Type: GrantFiled: August 6, 2008Date of Patent: May 28, 2013Assignee: Qinetiq LimitedInventors: Gregor John McDonald, Andrew Charles Lewin, David Arthur Orchard
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Patent number: 8384978Abstract: An optical clock comprises a laser oscillator and modulating means arranged to cooperate with the laser oscillator to produce a series a series of phase-modulated optical pulses. The optical clock further comprises an optical fiber arranged to provide compression of the optical pulses, and may also comprise a step-recovery diode arranged to pulse-pick pulses output from the fiber to produce a series of optical clock pulses, depending on the mode of operation of the modulating means. Phase-modulation is carried out a frequency which provides sufficient linewidth broadening to inhibit stimulated Brillouin scattering within the optical fiber. An optical clock of the invention provides a robust and reliable alternative to clocks based on modelocked lasers, and may be assembled from inexpensive, commonly-available components. The repetition rate of a clock of the invention may easily be adjusted by electronic means. Unlike many modelocked lasers, a clock of the invention does not require precise optical alignment.Type: GrantFiled: September 10, 2007Date of Patent: February 26, 2013Assignee: Qinetiq LimitedInventor: Gregor John McDonald
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Publication number: 20110116687Abstract: A method of classifying an object, in particular of classifying a vehicle by evaluating the degree of correlation between an image data set corresponding to an image of at least part of the vehicle and each of a plurality of reference data sets each of which corresponds to a reference image of a vehicle comprises the steps of establishing the vehicle's aspect and selecting the plurality of reference data sets from a larger group of such data sets on the basis of the vehicle's aspect. By selecting from the larger group only those reference data sets which correspond to the vehicle's aspect, faster classification is achieved for a given level of processing resources. Alternatively, for a given processing or classification rate, the level of processing resources may be reduced compared to the prior art.Type: ApplicationFiled: May 12, 2009Publication date: May 19, 2011Applicants: QINETIQ LIMITED, ADVANTAGE WEST MIDLANDSInventors: Gregor John McDonald, Jonathan Stanley Ellis, Douglas Alan Levenets
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Publication number: 20110002029Abstract: An optical clock for generating a series of optical clock pulses, comprises a laser source for generating output having a plurality of spectral components ?1, ?2, . . . ?N, an amplitude-modulator arranged to cooperate with the laser source to produce a series of intermediate optical pulses each having the plurality of spectral components, and optical fibre arranged to provide dispersion of each intermediate optical pulse to form a plurality of component pulses each corresponding to a spectral component and to compress each component pulse, the spectral width of each spectral component being sufficient to inhibit stimulated Brillouin scattering (SBS) of the component pulses within the optical fibre. The optical clock may be used for analogue-to-digital conversion of an electrical signal, in which application pulses of respective spectral components are demultiplexed and subsequently detected and digitised in parallel, providing for faster conversion.Type: ApplicationFiled: March 9, 2009Publication date: January 6, 2011Applicant: QINETIQ LIMITEDInventor: Gregor John McDonald
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Publication number: 20100265491Abstract: Range-finding apparatus comprises a source of pulsed radiation of variable repetition rate and a beam-splitter for dividing the pulsed radiation into two portions which are directed respectively to a local retro-reflector and to a retro-reflector co-located with a remote target the range of which is to be determined. The source, beam-splitter and retro-reflectors are arranged in the form of Michelson interferometer together with a detector. The repetition rate of the source is tuned to frequencies f such that round-trip distance to the remote target is mc/f where m is an integer, this condition being detected by observing a heterodyne signal at the detector. Two such frequencies enable range to be determined. The precision with which range is determined may be increased by carrying out interferometry using the two portions. The accuracy of the method does not depend on absolute range (as with triangulation) and is not limited by the speed of timing electronics, as is the case for time-of-flight techniques.Type: ApplicationFiled: August 6, 2008Publication date: October 21, 2010Applicant: QINETIQ LIMITEDInventors: Gregor John McDonald, Andrew Charles Lewin, David Arthur Orchard
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Publication number: 20100027087Abstract: An optical correlation apparatus is taught which provides a parallel optical signal having a phase modulation representing input data to which a parallel phase modulation based on reference data is applied. In the event of correlation the resulting wavefront is planar and can be interferometrically coupled to give a high intensity signal. The invention involves use of parallel amplitude modulation means for selectively blocking the optical signal in one or more of the channels of the parallel optical signal which allows different sized reference data strings to be searched more easily and also aids in calibration.Type: ApplicationFiled: December 17, 2007Publication date: February 4, 2010Applicant: QINETIQ LIMITEDInventors: Andrew Charles Lewin, Gregor John McDonald, Douglas Alan Payne, Rebecca Anne Wilson
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Publication number: 20100002281Abstract: An optical clock comprises a laser oscillator and modulating means arranged to cooperate with the laser oscillator to produce a series a series of phase-modulated optical pulses. The optical clock further comprises an optical fibre arranged to provide compression of the optical pulses, and may also comprise a step-recovery diode arranged to pulse-pick pulses output from the fibre to produce a series of optical clock pulses, depending on the mode of operation of the modulating means. Phase-modulation is carried out a frequency which provides sufficient linewidth broadening to inhibit stimulated Brillouin scattering within the optical fibre. An optical clock of the invention provides a robust and reliable alternative to clocks based on modelocked lasers, and may be assembled from inexpensive, commonly-available components. The repetition rate of a clock of the invention may easily be adjusted by electronic means. Unlike many modelocked lasers, a clock of the invention does not require precise optical alignment.Type: ApplicationFiled: September 10, 2007Publication date: January 7, 2010Applicant: QINETIQ LIMITEDInventor: Gregor John McDonald