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136results about How to "Improve spatial resolution" patented technology

Apparatus and method for efficiently increasing the spatial resolution of images

A method increases the spatial resolution of a source image based on an auxiliary, co-registered image of a higher spatial resolution. Each of the source and auxiliary images includes a plurality of pixels with corresponding spectral intensities and the method includes reducing, identifying, deriving, subdividing and modifying steps. Multiple auxiliary images can be used with the method.
In the reducing step, a spatial resolution of the auxiliary image is reduced to a common resolution with the source image. Then in the identifying step, corresponding groups of pixels at the common resolution in the source and auxiliary images are identified. Then in the deriving step, a mapping function is derived which relates the rate of change of intensity of each group in the auxiliary image and the corresponding rate of change of intensity in the corresponding group in the source image to the intensity vector. This map can be conditioned on any number of auxiliary image planes.
In the subdividing step, each source pixel is subdivided. Then in the modifying step, the spectral intensity of each subdivided source pixel is modifying based on the map and the local intensity variations of the auxiliary image. This results in increasing the resolution of the source image.
Owner:LOCKHEED MARTIN CORP

Gamma ray detector for positron emission tomography (pet) and single photon emisson computed tomography (spect)

The invention relates to a detector module (1) for a Positron Emission Tomograph (PET) and for Single Photon Emission Computed Tomography (SPECT) comprising a matrix (3) of scintillator crystals, said matrix having a first side and a second side opposite to said first side, each scintillator crystal having a first end (14) and a second end (15), said scintillator crystals (2) being oriented parallel to each other, whereby said first end (14) and said second end (15) of each of said scintillator crystals (2) coincide with said first side and said second side of said matrix (3), respectively; a first light sensitive detector (6) producing electrical signal proportional to the amount of light detected, being optically connected to said first side of said matrix (3), said first light sensitive detector (6) being position sensitive; and a second light sensitive detector (7) producing electrical signal proportional to the amount of light detected, said second light sensitive detector (7) being optically connected to said second side of said matrix (3), wherein said second light sensitive detector (7) is positioned sensitive. Using said detector module (1) a method to determine the 3D-coordinates of a point of interaction of a gamma quantum (γ1, γ2) with said detector module (1) is disclosed method. This allows to use signals from compton seattered γ's to enhance the sensitivity of a Positron Emission Tomograph scanner provided being composed of said detection modules (1) without parallax errors.
Owner:EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH

Laser scanning method and device for helicopter collision avoidance

InactiveCN103076614AImprove spatial resolutionReduce adverse effectsElectromagnetic wave reradiationReal-time scanMobile laser scanning
The invention discloses a laser scanning method and device for helicopter collision avoidance. The device comprises a collision avoidance laser scanner device, a helicopter body pitch angle measuring device and a helicopter body; and the device can be used for scanning and imaging a ground obstacle in real time and timely providing the shape and distance information of the obstacle for a pilot. The state of a laser scanning point cloud is decided by two-dimensional motion, wherein the two-dimensional motion comprises sinusoidal swing in a pitch direction and conical laser scanning formed by rotating motion of a scanning mirror; and the laser point scanning track of circular rotating propulsion is generated by synthesizing two motions and a rectangular scanning strip is formed, so that the obstacle at lower front part of the helicopter can be detected at high resolution. When a pitch angle of the helicopter changes, a pitch angle value is obtained by the helicopter body pitch angle measuring device and is provided for a collision avoidance laser scanner controller, so that a swing angle in the pitch direction is controlled in real time, the change of the pitch angle is compensated, the laser scanning pitch field angle is kept unchanged relative to the local horizontal plane and the phenomenon of leaked scanning of the ground obstacle at the lower front part of the helicopter due to the influence from the pitch angle change is prevented.
Owner:SHANDONG UNIV OF TECH

Underwater three dimensional terrain reconstruction method based on multi-beam sonar data

The invention discloses an underwater three dimensional terrain reconstruction method based on multi-beam sonar data, comprising the following steps of: firstly, collecting echo wave strength data and also measuring sounding data; secondly, carrying out linear interpolation on the sounding data and obtaining the sounding data having the same space resolution with the echo wave strength data; thirdly, calculating an angle and a range between a beam of each sounding data point and a horizontal line; fourthly, calculating the beam incident angle of each sounding data point by a point-by-point way; fifthly, fitting model parameters of a reflection model based on the echo wave strength data and correcting the angle between the beam and the horizontal line; seventhly, setting an iteration number N and enabling an average relative error absolute valve of estimated echo wave strength data and the collected echo wave strength data to be minimum; and eighthly, calculating sounding data and reconstructing an underwater three dimensional terrain. The method can enhance the space resolution of the sounding data and has an important significance on the aspects of underwater substance exploration, three dimensional visualization, underwater target detection and the like. The reconstructed underwater three dimensional terrain is also nearer to the real terrain.
Owner:SHANGHAI UNIV

Characterization method and test device for near-field terahertz THz time domain spectrum

The invention relates to a characterization method and a test device for a near-field terahertz THz time domain spectrum. The characterization method comprises the following steps: a near infrared femtosecond pulse laser beam which is radiated by a femtosecond laser source is split into a pump light path and a detection light path by an optical beam splitter; pump light is modulated by an opticalchopper, and excites a solid terahertz emitting source or a test sample in a nanoscale quasi one-dimensional structure so as to generate terahertz wave signals required by spectral analysis; detection light passes through an optical delay line and a necessary transmission light path, is superposed with the pump light path on a terahertz detection crystal, and samples terahertz signals; the terahertz signals sampled by the detection light pass through a quarter wave plate and a Wollaston prism and is split into P light and S light, the P light and the S light are put into the input end of a difference photodiode, the small signal output end of the difference photodiode outputs differential signals, and the differential signals are processed (amplified and subjected to analog-to-digital conversion) by a lock phase signal amplifier, wherein synchronous frequency signals of the lock phase amplifier come from the optical chopper; and the processed signal data are transmitted to a computer for further processing and operational analysis.
Owner:SOUTHEAST UNIV

Frequency modulated continuous wave (FMCW) frequency sweep non-leaner calibration system based on closed loop control and FMCW frequency sweep non-leaner calibration method based on closed loop control

InactiveCN105006736AThe output optical frequency linearity is improvedImprove spatial resolutionLaser detailsPhysicsRadio frequency
The present invention relates to an FMCW frequency sweep non-leaner calibration system based on closed loop control. The system comprises a frequency sweep laser source, a coupler, a delay optical fiber, an acousto-optic frequency shifter, a photoelectric detector, a frequency spectrum analyzer, a digital phase frequency detector and a summator. Meanwhile, the present invention provides a calibration method of the above system. The method comprises the steps of using the frequency sweep laser source to emit the optical signals of continuous phases, wherein one optical signal is delayed by the optical fiber, and the other one optical signal is carried out the optical frequency shift by the acousto-optic frequency shifter; after the two optical signals are combined, using the balance photoelectric detector to detect a beat frequency optical signal; using the digital phase frequency detector to compare the phases of the beat frequency optical signal and a radio frequency reference signal, and feeding back an outputted error signal to a laser after signal conditioning, thereby finishing the enclosed loop control of a whole loop. According to the present invention, the non-linear output optical frequency of the frequency sweep laser source is calibrated accurately, the output optical frequency linearity is improved obviously, and the spatial resolution of a FMCW ranging system is improved substantially.
Owner:SHANGHAI JIAO TONG UNIV

Crop maturation stage remote sensing prediction method based on multi-source remote sensing data

The invention provides a crop maturation stage remote sensing prediction method based on multi-source remote sensing data. The method comprises the steps that high temporal-spatial resolution remote sensing data are generated through the multi-source remote sensing data in a blended mode so that requirements for cropland dimension carrying-out dynamic monitoring of crop maturation stage prediction can be met; then, according to the dynamic change law of moisture content and chlorophyll content of different parts of maturation stage plants of crops, digital expression of the change law is formed. On the basis of the coupling method of the change law of biochemical parameters of the crops and biochemical parameters of the crops of remote sensing inversion, the moisture content and the chlorophyll content, obtained in a remote sensing mode, of crop canopies are combined to the change law of the biochemical parameters of maturation near stages of the crops, and the crop maturation stage remote sensing prediction method is formed. By means of remote sensing prediction of maturation stages of the crops, the application range of remote sensing in the accurate agricultural field is further extended, and the newly added technique of remote sensing application in the agricultural field is excavated.
Owner:INST OF REMOTE SENSING & DIGITAL EARTH CHINESE ACADEMY OF SCI

BOCDA (Brillouin Optical Correlation Domain Analysis) distributed optical fiber sensing device and method based on physical random code modulation

The invention relates to a distributed optical fiber sensing system, and particularly relates to a BOCDA (Brillouin Optical Correlation Domain Analysis) distributed optical fiber sensing device and amethod based on physical random code modulation, so as to solve the problems of a limited sensing distance and spatial resolution deterioration existing in the existing BOCDA distributed optical fibersensing system. The device comprises a distributed feedback semiconductor laser, an electro-optic phase modulator, a physical random code generator, a first optical isolator, a 1*2 optical fiber coupler, a high-speed electro-optic modulator, a microwave signal source, a variable optical delay line, a first optical amplifier, an optical polarization scrambler, a second optical isolator, a sensingoptical fiber, a second optical amplifier, an optical circulator, a tunable optical filter and a optical power detector. In comparison with a time domain system, the spatial resolution is higher, thesensing distance is longer, the problem of spatial resolution deterioration caused by existence of a weak period of chaotic laser signals is avoided, adjustment on the high spatial resolution acquisition is extremely convenient, and the signal-to-noise ratio of the sensing system is effectively improved.
Owner:TAIYUAN UNIV OF TECH

BOTDA (Brillouin Optical Time-domain Analyzer) system based on comb frequency spectrum continuous probe beam

The invention relates to a BOTDA system implement method based on a comb frequency spectrum continuous probe beam, which is characterized in that in the system, stimulated Brillouin scattering is generated by the comb frequency spectrum continuous probe beam as well as single frequency pumping pulse light with a wide narrow line; the comb frequency spectrum continuous probe beam is amplified by a stimulated Brillouin gain spectral line; an interval of an adopted comb frequency spectrum is larger than that of a required comb frequency spectrum with large frequency measurement precision; powers at the respective frequency positions are obtained through measurement via the powers of different frequencies in the comb frequency spectrum subjected to the stimulated Brillouin scattering; and finally, a complete Brillouin scattering spectrum is obtained in combination with a spectral line fitting algorithm to obtain temperature and strain at the space position. The BOTDA system has the beneficial effects that the dynamic property of the BOTDA system is improved, the spatial resolution is improved, the frequency spectrum scanning equipment of the system is simplified, the spectral line fitting speed is improved, the detect of restriction between a comb frequency spectrum interval and a pulse width is overcome, and the speed problem of a continuous frequency sweeping system is also solved.
Owner:NANCHANG HANGKONG UNIVERSITY

Stimulated Brillouin effect-based differential temperature sensor

The present invention provides a stimulated Brillouin effect-based differential temperature sensor. The continuous light generated by a light generating unit is subjected to a first modulation amplifier unit to obtain a signal containing the Stokes light and the anti-Stokes light. After that, the signal is subjected to a second modulation amplifier unit to generate a phase modulated signal. The modulated signal is subjected to a filter, so that the Stokes light and the anti-Stokes light are filtered out. The Stokes light passes through a delay optical fiber to be integrated with the anti-Stokes light as one path of optical signals through a 3 dB coupler. The path of optical signals is subjected to a polarizer, so that the polarized light can be extracted. The extracted polarized light is subjected to a third modulation amplifier unit to obtain the pumped pulse light. The pumped pulse light is injected into the initial end of a sensing optical fiber. The detection light of the other path is infiltrated through the tail end of the sensing optical fiber via a scrambler instrument and an isolator. Inside the optical fiber, the detection light forms a circulator together with the pumped pulse light under the stimulated Brillouin effect, and then is converted into an electric signal through a photoelectric detector. According to the technical scheme of the invention, the temperature resolution and the sensing distance are higher on the premise that the high spatial resolution is realized.
Owner:BEIJING UNIV OF POSTS & TELECOMM

Transparent object 3D surface reconstruction method and apparatus based on background schlieren technology

The invention discloses a transparent object 3D surface reconstruction method and apparatus based on background schlieren technology. The method includes the following steps: acquiring the angle value of the spatial bending angle which is formed by the light ray which is emitted by a light source and is further transmitted through a background image in the presence of a refractive index field and the light ray which is emitted by a light source and is further transmitted through a background image in the absence of a refractive index field; based on the acquired angle value of the spatial bending angle, obtaining a direction vector of the light ray which irradiates from the background image to a refraction point; based on the obtained direction vector which irradiates from the background image to the refraction point, determining the spatial coordinate of the refraction point and a normal vector in a tangent plane at the refraction point; based on the determined spatial coordinate of the refraction point and the normal vector in a tangent plane at the refraction point, reconstructing a 3D surface of the refractive index field. According to the invention, the method and the apparatus herein have the characteristics of simple configuration, high measured spatial resolution and low cost.
Owner:NAT UNIV OF DEFENSE TECH

Laser backlight surface light source

The invention provides a laser backlight surface light source which comprises a laser source, a beam-splitter mirror, a reflecting mirror, two beam expanding mirrors, two tiny light guide bars and a light guide plate, wherein the laser source is positioned in front of the beam-splitter mirror, and the reflecting mirror is arranged behind the beam-splitter mirror; the two beam expanding mirrors are respectively arranged at one side of the beam-splitter mirror and the reflecting mirror; the tiny light guide bars are embedded at the upper and the lower sides of the light guide plate and respectively positioned at one side of the two beam expanding mirrors; after being treated by light splitting and beam expanding, a laser beam passes through the two tiny light guide bars to form a cylinder or line light source evenly giving out light towards the side; and the light given out from the side of the tiny light guide bars enters the light guide plate for homogenizing light, so that the laser backlight surface light source can be formed. The light source has reasonable structure, and is far better than a backlight adopted by the existing liquid crystal display system in the aspects of color gamut range, color brightness degree and color fidelity when being used for liquid crystal display.
Owner:SHANDONG UNIV
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