1067 results about "Spectral resolution" patented technology

Nuclear magnetic resonance (NMR) signals are detected in microtesla fields. Prepolarization in millitesla fields is followed by detection with an untuned de superconducting quantum interference device (SQUID) magnetometer. Because the sensitivity of the SQUID is frequency independent, both signal-to-noise ratio (SNR) and spectral resolution are enhanced by detecting the NMR signal in extremely low magnetic fields, where the NMR lines become very narrow even for grossly inhomogeneous measurement fields. MRI in ultralow magnetic field is based on the NMR at ultralow fields. Gradient magnetic fields are applied, and images are constructed from the detected NMR signals.

A direct detector for terahertz radiation comprises a grating-gated field-effect transistor with one or more quantum wells that provide a two-dimensional electron gas in the channel region. The grating gate can be a split-grating gate having at least one finger that can be individually biased. Biasing an individual finger of the split-grating gate to near pinch-off greatly increases the detector's resonant response magnitude over prior QW FET detectors while maintaining frequency selectivity. The split-grating-gated QW FET shows a tunable resonant plasmon response to FIR radiation that makes possible an electrically sweepable spectrometer-on-a-chip with no moving mechanical optical parts. Further, the narrow spectral response and signal-to-noise are adequate for use of the split-grating-gated QW FET in a passive, multispectral terahertz imaging system. The detector can be operated in a photoconductive or a photovoltaic mode. Other embodiments include uniform front and back gates to independently vary the carrier densities in the channel region, a thinned substrate to increase bolometric responsivity, and a resistive shunt to connect the fingers of the grating gate in parallel and provide a uniform gate-channel voltage along the length of the channel to increase the responsivity and improve the spectral resolution.

Techniques for providing spectroscopic imaging integrates an acousto-optic tunable filter (AOTF), or an interferometer, and a focal plane array detector. In operation, wavelength selectivity is provided by the AOTF or the interferometer. A focal plane array detector is used as the imaging detector in both cases. Operation within the ultraviolet, visible, near-infrared (NIR) spectral regions, and into the infrared spectral region, is achieved. The techniques can be used in absorption spectroscopy and emission spectroscopy. Spectroscopic images with a spectral resolution of a few nanometers and a spatial resolution of about a micron, are collected rapidly using the AOTF. Higher spectral resolution images are recorded at lower speeds using the interferometer. The AOTF technique uses entirely solid-state components and requires no moving parts. Alternatively, the interferometer technique employs either a step-scan interferometer or a continuously modulated interferometer.

An optical slicer for generating an output spot comprising an image compressor which receives a substantially collimated input beam and compresses the beam, wherein the input beam, if passed through a focusing lens, produces an input spot; an image reformatter which receives the compressed beam to reformat the beam into a plurality of sliced portions of the compressed beam and vertically stacks the portions substantially parallel to each other; and an image expander which expands the reformatted beam to produce a collimated output beam which, if passed through the focusing lens, produces the output spot that is expanded in a first dimension and compressed in a second dimension relative to the input spot.

A spectrometer that provides the ability to combine the advantages of high resolution, compactness, ruggedness, and low-power consumption of Fabry-Perot (FP) tunable filter spectrometer, with the multi-channel multiplexing advantage of FT and/or grating/detector array. The key concept is to design and operate a tunable FP filter in a multiple-order condition. This filter is then followed by a “low-resolution” fixed grating, which disperses the filtered n-order signal into a preferably matched N-element detector array for parallel detection. The spectral resolution in this system is determined by the FP filter, which can be designed to have very high resolution. The N-order parallel detection scheme reduces the total integration or scan time by a factor of N to achieve the same signal to noise ratio (SNR) at the same resolution as the single channel tunable filter method. This design is also very flexible, allowing spectrometer systems with appropriate order N to thereby optimize the system performance for spectral resolution and scan integration time. In addition to the significant reduction in scan integration time, there are two other advantages to this approach. The first, because the FP tunable filter is designed and operated under n-orders, the fabrication tolerances of the FP filter cavity and operating conditions are significantly loosened.

An exemplary system and method for detecting at least one analyte in a sample comprises inter alia a source of radiation (300), a near-field aperture array (315), a chromatographic field (330), a detector (350), and a data processor (370). Disclosed features and specifications may be variously controlled, adapted or otherwise optionally modified to improve detection of any sub-diffraction-limited scale phenomena. Exemplary embodiments of the present invention representatively provide for improved S/N, increased sample throughput, refined spectral resolution and enhanced detection sensitivity.

Method and system for creating a fused image from an image pair comprising a high resolution panchromatic image and lower resolution multi-spectral image. The method includes obtaining image data (204) defining a first image of a panchromatic image type and a second image of a multi-spectral image type. The first image has a first spatial resolution and a first spectral resolution. The second image has a second spatial resolution which is lower than the first spatial resolution and a second spectral resolution higher than the first spectral resolution. The method also includes a step (212) of concurrently calculating a point-spread function for down-sampling the first image to the second spatial resolution, and a set of weights for down-sampling the second image to the first spectral resolution.

Nuclear magnetic resonance (NMR) signals are detected in microtesla fields. Prepolarization in millitesla fields is followed by detection with an untuned dc superconducting quantum interference device (SQUID) magnetometer. Because the sensitivity of the SQUID is frequency independent, both signal-to-noise ratio (SNR) and spectral resolution are enhanced by detecting the NMR signal in extremely low magnetic fields, where the NMR lines become very narrow even for grossly inhomogeneous measurement fields. Additional signal to noise benefits are obtained by use of a low noise polarization coil, comprising litz wire or superconducting materials. MRI in ultralow magnetic field is based on the NMR at ultralow fields. Gradient magnetic fields are applied, and images are constructed from the detected NMR signals.

The invention relates to a multi-parameter logging method while drilling based on a controllable neutron source, which includes the steps of utilizing a multi-detector measuring system consisting of the D-T controllable neutron source, two thermal neutrons and two gamma detectors, sufficiently utilizing fast neutrons transmitted by the controllable neutron source to militate with atomic nucleuses of formation elements by means of special pulse and measuring timing sequence design, recording gamma energy spectrums, gamma time spectrums and thermal neutron time spectrums at different positions, and performing simultaneous measurement of multiple parameters such as formation density, formation porosity, formation fluid saturation, formation element content and the like with a nuclear logging instrument in a drilling process by means of different spectral resolution and data processing, so that valuation on formation lithology, formation porosity and formation fluid saturation while drilling are realized, the same parameter of the formation porosity and the formation fluid saturation can be measured by various methods, logging interpretation ambiguity is decreased, and accuracy and reliability of logging data interpretation are enhanced.

The invention provides a temporal-spatial joint filtering high-resolution DOA (Direction of Arrival) estimation method based on a compressed sensing technology. The method comprises the following steps: (1) acoustic pressure vibration velocity joint temporal filtering, to be specific, carrying out rotating combination on the data of an acoustic vector sensor, and utilizing differences in the corresponding properties of a signal and noise to carry out denoising processing; (2) matrix spatial filtering, to be specific, carrying out spatial filtering on the temporally filtered data by a matrix spatial filter of which the maximum value of the mean square error of attenuation in a stop-band and a passband is minimum; and (3) compressed sensing DOA estimation by the array of the acoustic vector sensor, to be specific, receiving data and a manually formed spatial over-complete redundance dictionary via an input array preprocessed by temporal filtering, and seeking the sparse representation of the signal to carry out vector spatial spectrum estimation. The method has great spectral resolution capability in the high-resolution DOA estimation problem of a high-speed motion target under single snapshot conditions and is insensitive to the wideband and narrowband properties and coherent properties of the signal.

The invention discloses a spectrum polarization detection device and a method for synchronous polarization modulation interference imaging. The spectrum polarization detection device comprises a preposed polarization imaging system, an image plane interference imaging spectrometer and a signal processing system which are arranged on the same optical axis in sequence. Incident light forms four groups of light beams with different polarization state information through a polarization element and the light beams are separated on a space of a back focal plane of a microlens array. The separated light beams shoot into a lateral cutting beam splitter after passing through a collimator objective lens and are divided into two crosswise, and optical path difference information is brought in. Two branches of emergent light passes through a postpositional imaging objective lens, a target image with interference information and polarization state information is obtained on a target face of a detector, and the target image is transformed into an electrical signal and enters a signal processing system. Fourier transform is carried out, and light intensity information, spectral information and complete Stokes polarization information of a two-dimensional space of each target point are obtained. The spectrum polarization detection device for synchronous polarization modulation interference imaging has the advantages of being high spectral resolution, high in signal to noise ratio and simultaneous in complete Stokes polarization information and can be used for spectrum detection of a narrow band or a wide band.

A method and apparatus for enhancing the spectral resolution of magnetic resonance spectroscopic (MRS) measurements include receiving time domain echo data from an MRS measurement for an MRS volume in a subject. Also received are high spatial resolution complex signal values within the MRS volume based on magnetic resonance imaging (MRI) measurements. Frequency-domain content is determined for the echo data based at least in part on the complex signal values. For example, in some embodiments, receiving complex signal values includes receiving high spatial resolution complex signal values within the MRS volume for each of two different echo time settings. The frequency-domain content of the echo data is corrected for a lineshape profile based on high resolution frequency dispersion values for the MRS volume determined from differences in the complex signal values for the two different echo time settings.

The invention relates to a real-time calibration high spectral resolution lidar device for measuring atmospheric wind field. The invention comprises a transmitting system composed of a pulse laser, a beam expander and a reflector, a receiving system composed of a telescope, optical filters, a molecular iodine filter, beam splitters and photoelectric detectors, a data acquisition system connected with the photoelectric detectors, and a data processing computer. The invention is characterized by also comprising two receiving channels of the rotational Raman, and the two receiving channels of the rotational Raman are connected in parallel by the beam splitters, extracts atmospheric molecule rotational Raman spectrum from the original detecting signal, and connected with the data acquisition system, the data acquisition system is connected with the data processing computer and transmits the acquired information to the data processing computer. The invention is characterized in that gasoloid relative concentration and atmospheric parameters are obtained from primary optical detection, and simultaneously wind speed refutation is carried out, measurement efficiency and measurement accuracy are improved with the wind speed measurement accuracy reaching 1m/s.

Methods, systems and computer program products are provided for fusing images having different spatial resolutions, for example, different spatial and/or spectral resolutions. Data for at least two images having different spatial resolutions is obtained. A component analysis transform is performed on a lower spatial resolution image of the at least two images. A component of the component analysis transform of the lower resolution image containing a small amount of information associated with the low spatial resolution image is replaced with information from a higher spatial resolution image of the at least two images.

Terahertz spectroscopy methods that are fast and have excellent spectral resolution and that do not require background correction of the instrument response without sample are disclosed. In one instance, the methods include phase coherent chirp pulse generation and phase coherent detection.

A spectroscopic sensor for measuring flat sheet product is disclosed. The disclosed sensor uses a combination of spectrometers and single-channel detectors and filters together with a broadband source of illumination to optimally measure multiple properties of a flat sheet product. A spectrometer is used to measure over a spectral range where an easily configurable set of wavelength channels is needed and where the signal-to-noise ratios and spectral resolutions of the channels are consistent with the spectral range and number of pixels of the spectrometer; while one or more single channel detector and filter combinations are used to measure, with high signal-to-noise ratio, at specific wavelengths within or outside the spectral range of the spectrometer(s). Therefore, the single channel detectors can be used to complement the information provided by a spectrometer or to extend the working range of a spectrometer by providing single wavelength measurements anywhere in the visible, near-IR or mid-IR spectral regions.

A system (100) for processing remotely acquired imagery is provided. The system (100) includes a storage element for receiving imagery data defining a first image of a panchromatic image type using a sensor characterized by a panchromatic spectral response curve and a second image of a multi-spectral image type using at least one other sensor characterized by a plurality of multi-spectral response curves associated with a plurality of optical bands. The first image has a first spatial resolution and a first spectral resolution. The second image has a second spatial resolution lower than the first spatial resolution and a second spectral resolution higher than that first spectral resolution. The system (100) also includes a processing element configured for deriving a radiation transfer model based on meta-data associated with one of the first and the second image and for determining a set of spectral weights for down-sampling the second image to the first spectral resolution based on the radiation transfer model and the panchromatic and the multi-spectral response curves.

This invention discloses an Excitation Emission Matrix (EEM) fluorescence spectrometer system that uses an LED array to cause excitation emission matrix fluorescence that is imaged onto a spectrograph for sample identification and analysis. By using the LED array, the spectrograph requires only high spectroscopic resolution of about 1 to 5 nm in the fluorescence emission range and low excitation light resolution of about 14 to 73 nm in the excitation range. While individual LED optical excitation spectra may contain wavelength regions that overlap, as long as the various LEDs have different excitation wavelengths and intensities, spectral overlap does not preclude data analysis. The invention provides an EEM spectroscopy system that is not a high resolution such as a laser or lamp based excitation system, but instead uses a lower resolution, lower power LED system. The invention also provides results that are comparable to existing systems with lower component cost and lower power requirements while also optically stable, small, and easy to use.

Method and system for creating a fused image from an image pair. The method includes obtaining (204) image data defining a first image of a panchromatic image type and a second image of a multi-spectral image type. The first image has a first spatial resolution and a first spectral resolution. The second image has a second spatial resolution which is lower than the first spatial resolution and a second spectral resolution higher than the first spectral resolution. The first image and the second image are fused (216) to initialize a fused image having the first spatial resolution and the second spectral resolution. A blurring function is used (220) to help form the fused image.

An x-ray spectrometer system comprising an x-ray imaging system with at least one achromatic imaging x-ray optic and an x-ray detection system. The optical train of the imaging system is arranged so that its object focal plane partially overlaps an x-ray emitting volume of an object. An image of a portion of the object is formed with a predetermined image magnification at the x-ray detection system. The x-ray detection system has both high spatial and spectral resolution, and converts the detected x-rays to electronic signals. In some embodiments, the detector system may have a small aperture placed in the image plane, and use a silicon drift detector to collect x-rays passing through the aperture. In other embodiments, the detector system has an energy resolving pixel array x-ray detector. In other embodiments, wavelength dispersive elements may be used in either the optical train or the detector system.

A method and system for enhancing predictive accuracy of planet surface characteristics from orbit using an extended approach of Pan-Sharpening by using multiple high resolution bands to reconstruct high resolution hyperspectral image is disclosed. Sparsity based classification algorithm is applied to rock type classification. An Extended Yale B face database is used for performance evaluation; and utilizing deep Neural Networks for pixel classification. The present invention presents a system that can significantly enhance the predictive accuracy of surface characteristics from the orbit. The system utilizes complementary images collected from imagers onboard satellites. The present system and method generates high spatial high spectral resolution images; accurate detection of anomalous regions on Mars, Earth, or other planet surfaces; accurate rock/material classification using orbital data and the surface characterization performance will be comparable to in-situ results; and accurate chemical concentration estimation of rocks.

The present invention discloses an apparatus for measuring spectrum and image with high spatial resolution and spectral resolution. The apparatus comprises an imaging side telecentric lens for collecting light from an object, an optical slit positioned behind the imaging side telecentric lens, an aspheric lens for collimating lights from the optical slits, a dispersing device for separating the lights of different wavelengths into a plurality of sub-rays of different entrance angle, an achromatic lens for focusing the sub-rays, and an optical sensor for detecting the optical intensity of the sub-rays. The dispersing device can be a transmission or reflection diffraction grating, and the optical sensor may consist of a plurality of photo-detectors positioned in a two dimensional array.

A perceptual coder is disclosed for encoding image signals, such as speech or music, with different spectral and temporal resolutions for redundancy reduction and irrelevancy reduction. The image signal is initially spectrally shaped using a prefilter. The prefilter output samples are thereafter quantized and coded to minimize the mean square error (MSE) across the spectrum. The disclosed perceptual image coder can use fixed quantizer step-sizes, since spectral shaping is performed by the pre-filter prior to quantization and coding. The disclosed pre-filter and post-filter support the appropriate frequency dependent temporal and spectral resolution for irrelevancy reduction. A filter structure based on a frequency-warping technique is used that allows filter design based on a non-linear frequency scale. The characteristics of the pre-filter may be adapted to the masked thresholds, using techniques known from speech coding, where linear-predictive coefficient (LPC) filter parameters are used to model the spectral envelope of the speech signal. Likewise, the filter coefficients may be efficiently transmitted to the decoder for use by the post-filter using well-established techniques from speech coding, such as an LSP (line spectral pairs) representation, temporal interpolation, or vector quantization.