369 results about "Phase variance" patented technology

The object of the present invention is to provide an apparatus capable of X-ray imaging utilizing phase of X-rays with a simple construction. The X-ray imaging apparatus of the present invention is equipped with first and second diffraction gratings and an X-ray image detector. The first diffraction grating is constructed to generate the Talbot effect using X-rays irradiated at the first diffraction grating. The second diffraction grating is configured so as to diffract the X-rays diffracted by the first diffraction grating. The X-ray image detector is configured so as to detect the X-rays diffracted by the second diffraction grating. By diffracting X-rays diffracted by the first diffraction grating, the second diffraction grating is capable of forming image contrast caused by changes in phase of X-rays due to the subject arranged in front of the front surface of the first diffraction grating or between the first diffraction grating and the second diffraction grating. The X-ray image detector is capable of detecting X-rays creating image contrast.

A method for a short-term prediction of future ship motion in open water to furnish visual cueing information that can be remotely presented to a pilot during an aircraft landing is described. Two sets of samples of the sea surface geometry along a radial azimuth line from a ship as a function of elevation of a sensor are first acquired. These are compensated to remove the components due to the ship's motion. Two wave traces are then separately derived in Cartesian format from the two sets of acquired samples. These wave traces are subjected to a Fast Fourier Transform to detect the amplitudes and phases of the individual wavelength components. The direction of the wavelength components is determined using a measure of their phase change in the scan direction during the time interval between the two scans together with their measured wavelength. The amplitude, direction and phase of each component is utilized together with the known motion characteristics of the moving ship in order to derive a short-term prediction of future ship motion in the time domain. A quiescent period of the ship motion is located by comparing the short-term prediction with the pre-defined operating limit criteria. Finally, a message signal is transmitted to the pilot of the aircraft indicating Time-to-Land and the duration of the quiescent period.

Variations in spatial phase distribution due to static magnetic field changes are corrected based on phase variations at points, specifically, at three points or a plurality of points selected by ROI, in an area where no temperature change is encountered. And a temperature distribution image is determined by using a spatial phase distribution reflecting only temperature changes after the correction, thereby high-accuracy temperature distribution image information is provided.

A method and apparatus for reading a microbead having a code thereon is provided wherein the code is projected on and read from a Fourier plane. The microbead may be 1-1000 microns (um) or smaller in feature size. The code is projected on the Fourier plane by scattering input light off the microbead. The scattered light from the microbead is directed through an optical arrangement having a transform lens for projecting the code on the Fourier plane, and read on the Fourier plane using a charge coupled device (CCD) or other similar device. The code may include periodic layers of material having different refractivities or phase, including index of refraction differences; periodic spatial modulations having a different phase or amplitude; a periodic binary phase change used to code information in the Fourier plane; a photonic crystal used to encode the information on the microbead, wherein a pattern of holes causes interference between incident and scattered light to form spatial and spectral patterns in the far field that are unique to the pattern of holes; or may be formed in the microbead using a single photoactive inner region, a series of longitudinal holes, different fluorescence regions, or concentric rings of material in a preform.

An optical frequency comb calibration-based dual-color laser scanning absolute distance measuring device and a method are characterized in that the device comprises a laser light source system, a polarization-maintaining optical fiber system, a Michelson interference system and a laser frequency calibration system. The method comprises the steps of controlling two tunable lasers in the laser light source system to continuously simultaneously adjust the output light frequency without mode skips, wherein the laser frequency calibration system records the interference signal of the Michelson interference system and a beat frequency signal of the tunable lasers and the optical frequency comb; computing the scanning range of the lasers and the period integer and period decimal of the phase change of the interference signal in the scanning process according to the collected data; and finally computing to obtain the absolute distance of a to-be-measured light path refractive face. The optical frequency comb calibration-based dual-color laser scanning absolute distance measuring device and the method have the advantages of simple system structure, high measuring precision, compensating effect on air refractive index, and traceable measuring outcome, and are suitable for the measuring field of space absolute distance.

A path detector (140) detects a plurality of multi-path waves that have satisfied a predetermined standard from reverse spread signals, a plurality of adders (161) form beams on the basis of a path, a plurality of transfer path estimating sections (170) and complex conjugate calculators (163) calculate a transfer path estimation value, and based upon the result of the estimation, carry out a weighting process in accordance with the signal amplitude and a removing process of the phase variations. Moreover, a plurality of interference amount estimating sections (171) extract the amount of interference, a plurality of normalizing sections (172) normalize the signals that have been subjected to the phase variation removing process based upon the amount of interference, an adder (185) combines all the signals that have been normalized, and a data determining section (190) determines the signal that have been combined.

The present invention integrates the surface plasmon resonance and common-path phase-shift interferometry techniques to develop a microscope for measuring the two-dimensional spatial phase variation caused by biomolecular interactions on a sensing chip without the need for additional labeling. The common-path phase-shift interferometry technique has the advantage of long-term stability, even when subjected to external disturbances. Hence, the developed microscope meets the requirements of the real-time kinetic studies involved in biomolecular interaction analysis. The surface plasmon resonance microscope of the present invention using common-path phase-shift interferometry demonstrates a detection limit of 2×10⁻⁷ refractive index change, a long-term phase stability of 2.5×10⁻⁴π rms over four hours, and a spatial phase resolution of 10⁻³ π with a lateral resolution of 100 μm.

Disclosed is a phase noise compensation apparatus to be applied to the OFDM system, comprising an ICI estimating unit for estimating inter carrier interference (ICI) using a pilot sub-carrier included in a reception signal, a estimating unit for estimating a common phase error (CPE), which is a phase noise from the reception signal as sampled, using the pilot sub-carrier, and estimating a transmission signal by removing the estimated CPE from the reception signal, a calculating unit for calculating phase change by the ICI in the reception signal by convoluting the ICI and the transmission signal, and an equalizer for compensating the calculated phase change by the ICI in the reception signal. Accordingly, phase noise can be exactly compensated by estimating as phase noise the result of convoluting a received signal where the CPE is removed in a frequency domain and the estimated ICI according to the present invention.

The invention relates to a method and system of adopting space phase modulation and interference array to detect the biochip, which belongs to biological technical field. The invention aims to overcome the deficiency of current technique and provides a new biochip detecting method and system, which can detect different volumes of DAN chips and protein chips dispense with mark and real-time achieve the information about the interaction of the biomolecules. The principle of the detection by space phase modulation and interference array is: the light reflected by the biosensor unit entering wallaston prism after combined by the one dimensional magnifying lens, the contained s ray and p ray which is polarizationdirection is divided into the two rays transmitting in different direction and realizing co-lightpath space phase modulation and interference in wallaston prism; the interference fringe being converted into electrical signal through the polarizer and imaging lens, the information of real-time phase change of the each unit on the array chip being acquired after processing and be offered to the biologist and medical scientists to parse.

A radio receiving apparatus capable of making compensation for both amplitude variations and phase variations and of suppressing image interference in a short period of time is provided.

A correction value calculation section (110) combines a signal, obtained by multiplying a first digital signal by an amplitude correction candidate value and rotating the phase of the first digital signal, with a signal obtained by multiplying a second digital signal by a multiplicative inverse of the amplitude correction candidate value and performing, for the second digital signal, phase rotation which is in a quadrature relationship to phase rotation performed for the first digital signal, so as to obtain a first combined signal, obtain an inflection point of the first combined signal, and input, to a demodulation section (120), the amplitude correction candidate value and a phase correction candidate value, which correspond to the inflection point, as an amplitude correction value and a phase correction value, respectively. The demodulation section (120) makes compensation for the amplitudes and the phases and suppresses image interference, based on the amplitude correction value and the phase correction value.

A photo-thermal interferometric spectroscopy system is disclosed that provides information about a chemical at a remote location. A first light source assembly is included that emits a first beam. The first beam has one or more wavelengths that interact with the chemical and change a refractive index of the chemical. A second laser produces a second beam. The second beam interacts with the chemical resulting in a third beam with a phase change that corresponds with the change of the refractive index of the chemical. A detector system is positioned remote from the chemical to receive at least a portion of the third beam. An adaptive optics system at least partially compensates the light beam degradation caused by atmospheric turbulence. A focusing system is used to bring together the light passed through the chemical; the focusing system includes a multimode fiber for the light collection, The detector system provides information on a phase change in the third beam relative to the second beam that is indicative of at least one of, absorption spectrum and concentration of the chemical.

A disturbance, such as vibration from human activity, is located along a fiberoptic waveguide configuration (301-304) with two interferometers (801, 802) of the same or different types, such as Mach-Zehnder, Sagnac, and Michelson interferometers. Carrier signals from a source (101) are split at the interferometer inputs (201, 202) and re-combined at the outputs (701, 702) after propagating through the detection zone (401), where phase variations are induced by the disturbance (501). Phase responsive receivers (901, 902) detect phase relationships (1001, 1002) between the carrier signals over time. A processor (1101) combines the phase relationships into composite signals according to equations that differ for different interferometer configurations, with a time lag between or a ratio of the composite signals representing the location of the disturbance. The detected and composite values are unbounded, permitting phase displacement to exceed the carrier period and allowing disturbances of variable magnitudes to be located.

Provided herein are systems and methods for achieving long coherent integration in a navigational receiver to improve the sensitivity of the receiver and enable the receiver to acquire, reacquire and track signals under very weak signal conditions. In an embodiment, phase compensation is computed based on estimated Doppler frequency, rate of change of the Doppler frequency with time, and second order rate of change of the Doppler frequency. The Doppler frequency may be computed from an orbital model or ephemeris. This phase compensation is used to compensate samples of the input signal for changes in the phase due to the Doppler frequency. Frequency components of the phase-compensated samples are then computed using a frequency analysis such as a Fast Fourier Transform (FFT). The maximum frequency component is taken as an error frequency and used to compensate the samples of the input signal for residual frequency error.

A phase change material is applied as a very thin film to a transparent substrate such as glass, which material when switched from the amorphous to the crystalline state and back again can affect the reflectivity/transmittance of the combined substrate-coating system. When used with glass panels in the fabrication of relatively large area window glass, the change in spectrally selective transmittance can be used to modulate the amount of sunlight passing through the glass, and thus reduce the amount of cooling required for an interior space in the summertime, and the amount of heating required of that same interior space in the wintertime, while also optimizing the use of visible daylight. Exemplary of a suitable phase change material for glass coating is GeSb or BiSn. Heating of the phase change material to initiate a change in phase can be provided by the application of electric energy, such as supplied from a pulsed power supply, or radiant energy, such as from a laser.