436 results about "Angular resolution" patented technology

Methods and apparatus for light-field imaging. Light-field camera designs are described that produce higher spatial resolution than conventional plenoptic camera designs, while trading-off the light-field's angular sampling density. This lower angular resolution may be compensated for by a light-field image processing method that inserts data synthesized by view interpolation of the measured light-field. In one embodiment, a light-field image processing method that performs three-view morphing may be used to interpolate the missing angular samples of radiance. The light-field camera designs may be implemented in hand-held light-field cameras that may capture a light-field with a single exposure. Some of the light-field camera designs are internal to the camera, while others are external to the camera. One light-field camera design includes a single, relatively large lens and an array of negative lenses that are placed in front of (external to) the main lens of a conventional camera.

There is provided an optical device, having a light-transmitting substrate (20) having at least two major surfaces parallel to each other and edges; a display light source; optical means for coupling light from the light source into the substrate (20) by internal reflection, and at least one partially reflecting surface (22) located in the substrate (20) which is non-parallel to the major surfaces of the substrate wherein the source emits light waves located in a given field-of-view, that the light waves are collimated, that an angular resolution is defined for the optical device, and wherein the angular deviation between any two different rays located in one of the collimated light waves, is smaller than the angular resolution.

A method of detecting a lane change of a subject vehicle (20), having a locating device (10) which uses angular resolution for locating vehicles (VEH1, VEH2, VEH3) traveling in front, and a device (44) for determining the yaw rate (omega0) of the subject vehicle. The angular velocity (omegai) of at least one vehicle traveling in front relative to the subject vehicle (20) is measured using the locating device (10), and a lane change signal (LC) indicating the lane change is formed by comparing the measured angular velocity (omegai) to the yaw rate (omega0) of the subject vehicle.

An apparatus for estimating direction of arrival of signal is provided that has excellent performance in terms of angular resolution and the number of signals that can be identified. In an array sensor comprising a plurality of sensor elements, the two outermost sensor elements are alternately selected by a switch for use as a transmitting sensor, and the other sensor elements are selected in time division fashion as receiving sensors. With this arrangement, the effective aperture is increased to about twice the physical aperture, to improve angular resolution in a direction-of-arrival estimator.

A method for operating a radar system using at least two antennas provides an increased angular resolution for determining the angular position, radial velocity, and / or distance to a reflection object. A plurality of successive measuring phases are carried out in at least one measuring process. In each measuring phase, operation is repeatedly switched between a transmitting operation in which a transmitted signal pulse is emitted, and a receiving operation in which reflection signals are detected as received signals in the pulse pause interval between successive transmitted pulses. In at least one measuring phase, two different neighboring antennas of the radar system are used respectively as the transmitting antenna for emitting the transmitted signal and as the receiving antenna for detecting the reflected signal. In this manner, the respective receiving antenna monitors only the angular range of overlap between the emitted beam of the transmitting antenna and the field of view of the receiving antenna. The information provided by the detected signals in this overlapping angular range achieves an increased angular resolution. The method is particularly suitable for operating a separation distance warning system for a motor vehicle.

The invention discloses a roll angle measuring method based on a grating and a device thereof, which belongs to the technical field of photoelectric detection. A laser lases and emerges directly, or emerges after collimation through a collimating lens; the light is directly incident on a one-dimensional plane transmission grating, or reversely incident on the grating through a retrodirective reflector; plus-minus first stage diffracted light from the grating is focused to form two diffracted light points through a lens; a photodetector is used to detect the variations in positions of the two focused light points, thus figuring out a roll angle. The optical structure of the device is compact and simple, and brings convenience to practice; in addition, the accuracy, the stability and the economical efficiency are also high. The grating is used as a sensitive device; error separation is achieved, and the interference-free feature is improved by using the differential measurement of double diffracted beams; few optical devices are used; and the power of the light source is low; the cost is low; mobile parts do not require to be provided with cables; the angle measurement distinguishability is as high as 0.5 and even higher; different requirements of measurement accuracy can be met just by replacing the grating with gratings having different numbers of lines.

The invention belongs to the field of signal processing, aims to solve the problem that a traditional DOA (direction of arrival) estimation algorithm is large in sampling data volume to cause high computation complexity, and provides a beam-domain-based multi-measurement-vector underdetermined system regularization focusing solving (BS-RMFOCUSS) algorithm on the basis of a compressed sensing theory by using airspace sparsity of target signals. According to the algorithm, a target compressing signal is mapped to a beam domain from an element domain, the shortcoming that a sparse reconstructing algorithm cannot be used under the condition of low signal to noise ratio is overcome to a certain degree, and the algorithm complexity is low. Numerical simulation shows that the property of the algorithm is superior to that of the traditional DOA estimation algorithm, and the algorithm has high angular resolution and estimation precision, and can carrying out effective DOA estimation on coherent signals.

A detector assembly for detecting radiation with angular resolution comprises at least one detector element, which comprises a front face and a rear face, a first detector material and a second detector material between the front face and the rear face, a space between the front face and the rear face of the detector element being filled by a plurality of regions of the first detector material and at least one region of the second detector material and each region connecting the front face to the rear face of the detector element; and radiation incident on the detector element through the front face being collimated by means of the detector materials.

The disclosure provides an approach for estimating depth in a scene. According to one aspect, regions where the depth estimation is expected to perform well may first be identified in full-resolution epipolar-plane images (EPIs) generated from a plurality of images of the scene. Depth estimates for EPI-pixels with high edge confidence are determined by testing a number of discrete depth hypotheses and picking depths that lead to highest color density of sampled EPI-pixels. The depth estimate may also be propagated throughout the EPIs. This process of depth estimation and propagation may be iterated until all EPI-pixels with high edge confidence have been processed, and all EPIs may also be processed in this manner. The EPIs are then iteratively downsampled to coarser resolutions, at which edge confidence for EPI-pixels not yet processed are determined, depth estimates of EPI-pixels with high edge confidence made, and depth estimates propagated throughout the EPIs.

A three-dimensional video laser radar system based on acousto-optic scanning comprises a laser, a laser emission module, a laser receiving module, a signal processing module, a master control circuit module and an upper computer processing program module. The three-dimensional video laser radar system based on acousto-optic scanning overcomes the defects that in a three-dimensional imaging laser radar application based on a traditional scanning method, the imaging speed is low and the size and mass are large, two-dimensional acousto-optic scanning devices are utilized to quickly and flexibly change scanning angles, the scanning angle range and angular resolution, three-dimensional video imaging is achieved, and demands of special occasions with a high imaging speed requirement can be met; meanwhile, the advantages of the small size, light weight, low power consumption and the like of the two-dimensional acousto-optic scanning device are made use of, so the size and weight of the system are greatly reduced.

A simple circuit configuration without increasing the number of magnetic poles of a magnet can be performed and angular resolution can be improved. The polarities is determined and the absolute values are compared in accordance with the rotation angle of a magnet (1) based on sensor output signals a and b outputted from the magnetic sensors (2) and (3) to produce polarity determination signals c and d and absolute-value-comparison signals e, f, and g. The rotation angle of the magnet (1) is determined based on the polarity determination signals c and d and the absolute-value-comparison signals e, f, and g to output a determination result signal h.

An automotive radar system includes a beamformer circuit and a beamcombiner circuit. The beamformer circuit forms a plurality of antenna beams at a plurality of beam ports. The beam combiner circuit receives the beams provided thereto from the beamformer circuit and combines the beams to provide a desired number of beams, with each of the beams having a desired beam shape. In one embodiment, the beamcombiner provides first and second end beams having a beamwidth which is less than a beamwidth of middle beams.

The present disclosure relates to the generation of dual-energy X-ray data using a data sampling rate comparable to the rate utilized for single-energy imaging. In accordance with the present technique a reduced kVp switching rate is employed compared to conventional dual-energy imaging. Full angular resolution is achieved in the generated images.

Provided is a method for beam forming and beam pattern optimization based on an L-shaped array antenna, and the invention relates to the fields of beam forming and beam pattern optimization of an antenna. According to the invention, in order to solve the problems of low beam pattern angle measurement resolution and angle measurement accuracy resulting from less array elements in the traditional L-shaped array, the method comprises steps of: firstly, establishing a beam pattern F of an antenna for the L-shaped array by using a beam forming method in two-dimensional space, encoding an array structure of the L-shaped array, then adjusting the codes and building a fitness function, and with the beam pattern performance as an optimization target, organizing and optimizing the L-shaped array with a genetic algorithm to obtain an optimized non-uniform L-shaped array element arrangement; on the basis of the array element arrangement, further establishing a fitness function, and by using the genetic algorithm, calculating an optimal weight w for each array element of the L-shaped array; and introducing the optimized non-uniform L-shaped array element arrangement and the weight w into the beam pattern F to implement beam pattern optimization. The present invention is applicable to beam forming and beam pattern optimization of the L-shaped array antenna.

The invention discloses a radar target two-dimensional imaging method based on vortex electromagnetic waves. The radar target two-dimensional imaging method is based on an echo model of ideal scattering points under projection of the vortex electromagnetic waves generated by a uniform loop antenna array, performs orbital angular momentum (OAM) mode sampling on radar target echo signals and calculates a related function, adopts a multiple signal classification (MUSIC) algorithm to obtain a spatial spectrum function, and carries out two-dimensional spectrum peak searching to realize two-dimensional joint detection of a pitch angle and an azimuth angle of a radar target. Compared with a traditional direction-of-arrival (DOA) estimation scheme based on a plane wave MUSIC algorithm, the radar target two-dimensional imaging method provided by the invention can realize higher angular resolution; and compared with an existing radar target azimuth angle imaging scheme based on vortex electromagnetic waves, the radar target two-dimensional imaging method can realize the imaging of the target pitch angle without increasing hardware cost, and is of great reference significance to the modern radar design of the new system.

The invention belongs to the monostatic MIMO (multiple-input-multiple-output) radar system technical field and relates to a four-order cumulant sparse representation-based MIMO (multiple-input-multiple-output) radar direction of arrival estimation method under a mutual coupling condition. The method of the invention comprises the following steps that: a transmitting array transmits mutually-orthogonal phase encoding signals, a receiving end carries out matched filtering on the phase encoding signals so as to obtain receiving data, and the influence of unknown mutual coupling is eliminated through linear transform based on the strap-shaped symmetric Toeplitz structures of the mutual coupling matrixes of the transmitting array and the receiving array; and a dimension reduction conversion matrix is constructed to carry out dimension reduction processing on mutual coupling-eliminated data, and a four-order cumulant matrix of a special form is constructed based on a new data matrix. According to the method of the invention, since the four-order cumulant technique and a weighted sparse representation framework are adopted, colored noises are successfully inhibited. The method of the invention can achieve accurate direction of arrival estimation under a Gaussian color noise condition, and has higher angular resolution and better angle estimation performance.

The invention relates to a laser radar system, a laser radar point cloud data processing method and a readable medium. The laser radar system comprises a scanning module and a plurality of laser transmitting and receiving modules; the scanning module is suitable for reflecting laser pulse signals into a space, and receiving laser pulse echo signals reflected by a space obstacle; each laser transmitting and receiving module emits laser to the scanning module with a preset angle corresponding to the laser transmitting and receiving module; and fields of view corresponding to at least two laser transmitting and receiving modules have an overlapping region. With the above laser radar system adopted, the angular resolution of a laser radar can be improved at a lower cost and with lower system processing complexity.

The invention relates to a gaze-type high-resolution 3D imaging detector. The technical proposal of the invention is that the invention comprises an optical coherent fiber bundle formed by optical fibers and a photo sensor. One end of the optical fiber in the optical coherent fiber bundle is bound together with the end surface forming the imaging surface while the other end coupling with the photo sensor. To solve the technical problems in the background technique, the invention provides the gaze-type high-resolution 3D imaging detector, combining optical coherent fiber bundle and a plurality of units of photodetectors with high angular resolution and rapid response.

The invention belongs to technology for simultaneously measuring the directions of a plurality of wireless signal interference sources, which comprises the following steps of: setting sparse dictionaries, establishing interference source incoming wave azimuth column vectors, establishing an interference source detection data matrix, determining a direction bit matrix and determining the directions of the interference sources. In the technology, the sparse dictionaries are constructed at a set angular resolution interval in the range of 1 degree to 360 degrees according to the array manifold of a receiver array by utilizing phase jump times and the sparse characteristics of space distribution of the interference sources, and are taken as basic parameter sets in the determination of the directions of the plurality of interference sources; and each receiver simultaneously acquires the plurality of interference sources. Therefore, the technology has the characteristics of effectively solving the problem of performance reduction caused by phase jump, maximally reducing high requirements on consistency among channels of the receivers, greatly reducing difficulties in work of a system, and the like, and overcomes the defects of extremely high requirements on the consistency among the channels of the receivers, great influence of the phase jump on direction measurement accuracy, and the like in the prior art.

A rotation measurement system comprises a rotatable annular magnetic encoder 16 carrying a series of encoding elements 23 arranged around the circumference of the encoder according to a periodic pattern, characterized in that it comprises a primary sensor assembly 38 comprising at least a primary magnetic sensor 38 disposed facing the encoding elements for detecting the angular position of the encoder with a discrete angular resolution of a fraction of a revolution equal to or less than one period of the encoder and an electronic counter for the number of fractions of a revolution made, and a secondary sensor assembly comprising secondary magnetic sensors 24a to 24d, 25a to 25d disposed facing the encoding elements for determining an absolute position of the encoder between two positions separated by at least one fraction of a revolution.

The invention provides a high-angular-resolution light filed obtaining device and an image generation method. The high-angular-resolution light filed obtaining device in which a light coding aperture is combined with a micro lens array is constructed to solve the problem that resolution tradeoff causes low spatial resolution or image aliasing leads to decrease of the quality of a light field image. The high-angular-resolution light filed obtaining device comprises a main lens, the coding aperture, the micro lens array and a sensor which are successively arranged along a light transmission path. On the premise that the positional resolution of the light field is not increased, depth information in light field data is used to improve the angular resolution of the light field. The high-angular-resolution light filed obtaining device has the advantages of being high in the angular resolution, high in the signal to noise ratio, high in the passing rate and capable of collecting light-field videos. The light-field image generation method using the compressed sensing theory has the advantages of being high in the angular resolution and capable of removing image aliasing.

The invention provides a method and a device for simultaneously measuring five degrees-of-freedom errors based on light beam drift compensation. The method and the device are used for solving the problems of low measurement precision, small measurement range and poor anti-interference capability of the existing high-precision simultaneous measurement method for guide rail five degrees-of-freedom. A collimating lens, a prism assembly, a polarization beam splitting prism and a quarter-wave plate are arranged between a laser device and a right-angle prism plated with a beam splitting film, so as to realize processing of incident light and reflected light, information of the reflected light and transmitted light after beam splitting is received and measured by means of a four-quadrant detector and a position sensitive detector, and the measurement of pitch angle, deflection angle and rolling angle errors, horizontal straightness errors, vertical straightness errors and light drift compensation are realized. The method and the device utilize double beam differential measurement to realize error separation, enhance the anti-interference capability, employ few optical devices and are low in light source power and cost; the optical structure is simple, the operation is convenient, the moving parts are not required to be provided with cables, and the field measurement is facilitated; and the angle measurement resolution is high.

A radar sensor having multiple antenna elements for transmitting and receiving radar signals, an associated transmitting and receiving element and an evaluation device for determining the azimuth angle of located objects on the basis of a relationship between the signals received from different antenna elements, wherein the transmitting and receiving element is designed to supply to the antenna elements transmission signals in parallel, the frequencies of which are offset with respect to one another, and the evaluation device is designed to distinguish between signals that were transmitted by different antenna elements on the basis of the frequency offset.

The invention discloses a semi-physical simulation landing guide analog system based on a decimeter-wave instrument landing system. The semi-physical simulation landing guide analog system is characterized by comprising a ground equipment simulator for simulating a localizer, a glide-slope localizer and a ranging response signal of the decimeter-wave instrument landing system according to an instruction of the simulator and providing simulated angle information and distance information for airborne equipment, and an airborne equipment simulator for demodulating and decoding the simulated information sent from the ground equipment simulator and providing the simulated information to a flying control system. The semi-physical simulation landing guide analog system has the beneficial effects that the processes of navigation audio signal generation, angle beacon calculation and calibration, control and detection and the like are all digitalized; the ground equipment simulator adopts a digital pulse amplitude modulation mode for generating a simulated high angular resolution signal, and the airborne equipment simulator adopts a digital filtering mode and the like for effectively improving the calculating precision and the ranging precision of an angle localizer; the circuit multiplexing degree is high, the working process is stable and reliable, and the intelligentization, integration and miniaturization are realized.