40 results about "Aspect angle" patented technology

A target recognition system and method wherein only target amplitude data, i.e., coherent A-scan data, is interrogated for target recognition. Target aspect angle is ignored within the angular segmentation of the feature library without degrading classification performance. Observed signature characteristics are collected at various aspect angles and through unknown and arbitrary roll, pitch and yaw motions of each anticipated target and provided to a neural network as training sets. The neural network forms feature vectors for each target class which are useful for valid classification comparisons in all sea states, especially in calm and littoral waters. These feature vectors are useful for valid classification comparisons over at least 30 degrees of target aspect angle.

This invention relates to optical-electronic technology and can be used for building 3-dimensional displays for computers, television (TV) receivers and other devices, as well as for building systems for volumetric television. The technical result is an increase in the number of aspect angles with relatively simple construction and the use of presently available components. The equipment generates a 3-dimensional representation and contains a display component for 2-dimensional representation with digital inputs and a first 2-dimensional matrix of converging micro-lenses, in which each micro-lens is optically joined to the corresponding region of the display surface of the component for display of 2-dimensional representations. The equipment is equipped with second and third 2-dimensional matrices of micro-lenses, tightly connected to each other and coaxially placed and optically joined to the micro-lenses of the first matrix, forming in conjunction with the first matrix a matrix of scanning elements for sequential projection of 2-dimensional representations in the plane of their aspect angles, an adjustment mechanism of the matrices of micro-lenses, a positional sensor for adjustment of the micro-lenses and a controller connected to the adjustment mechanism through the digital input of the controller, providing the ability for synchronization of the frames of the representation of each 2-dimensional representation with the corresponding position of the matrix of micro-lenses, while the second matrix is arranged in the foreground focal plane of the third matrix, mixed with the background focal plane of the first matrix, and the first matrix or the combined second and third matrices can be adjusted in the plane in which they are installed, and moreover for the first, second and third matrices, the digital input of the display component is connected to the module of buffered memory, whose synchronization input is connected to the output of the controller. The described equipment can be used with a stereoscopic television system.

A plurality of image chips (202) (over 100), each of the chips containing the same, known target of interest, such as, for example an M109 tank are presented to the system for training. Each image chip of the known target is slightly different than the next, showing the known target at different aspect angles and rotation with respect to the moving platform acquiring the image chip.

The system extract multiple features of the known target from the plurality of image chips (202) presented for storage and analysis, or training. These features distinguish a known target of interest from the nearest similar target to the M109 tank, for example a Caterpillar D7 bulldozer. These features are stored for use during unknown target identification. When an unknown target chip is presented, the recognition algorithm relies on the features stored during training to attempt to identify the target.

The tools used for extracting features of the known target of interest as well as the unknown target presented for identification are the same and include the Haar Transform (404), and entropy measurements (410) generating coefficient locations. Using the Karhunen-Loeve (KL) transform 406, eigenvectors are computed. A Gaussian mixture model (GMM) (507) is used to compare the extracted coefficients and eigenfeatures from the known target chips with that of the unknown target chips. Thus the system is trained initially by presenting to it known target chips for classification. Subsequently, the system uses the training in the form of stored eigenfeatures and entropy coefficients fused with multiscale features to identify unknown targets.

A tomographic volumetric x-ray imaging system that uses either multiple x-ray sources in a fixed configuration or a single source that can be shifted to provide a plurality of incident aspect angles. A combination of volumetric x-ray image data and multi-energy image acquisition provides an effective method for high confidence explosives detection within baggage or parcels.

The invention provides a high-accuracy nonlinear path tracking control method for an under-actuated marine vehicle. According to the method, the change rate of the sideslip angle of the vehicle is regarded as an uncertain item, the parameter uncertainty in a dynamic model, unmodeled dynamics and external environmental disturbances are regarded as lumped uncertainty, and an observer is adopted to conduct real-time observation on kinematic uncertainty and dynamic uncertainty; a traditional aspect-angle guiding method is adopted to calculate an expected aspect angle; a nonlinear path tracking controller based on the observer is designed, and the kinematic and dynamic uncertainty are compensated; a tracking differentiator is adopted to simplify the controller to make the controller more suitable for engineering application. According to the method, the influences of the parameter uncertainty in the dynamic model, the unmodeled dynamics and the external environmental disturbances on path tracking are eliminated, and the accurate tracking control over an expected path of the vehicle is achieved.

The invention discloses a method for guiding an input constraining differential game based on self-adaptive dynamic planning. According to the method, a solving problem of an HJI equation and an input saturation problem in a nonlinear differential game problem are solved; an input constraining solving problem of the nonlinear differential game is solved by virtue of a self-adaptive dynamic planning technique, and a neural network and a Lyapunov method are combined so as to obtain a guidance control volume; and an input constraining differential game guidance law can be online obtained in real time based on an evaluation network updating law, and the aspect angle velocity in a guided missile-target relative motion relation tends to 0, so that the successful interception is guaranteed.

Automatic target recognition system and/or method which employs an elliptical Laplacian pyramid based pre-screen image data filter. The filter is a resolution sequence matched filter, where the elliptical Laplacian operator reflects the size, spatial characteristics and image intensity level of prospective, candidate targets embedded in the image data. Targets which exhibit a rectangular or elliptical shape at various aspect angles are more therefore more effectively and efficiently identified and located.

The invention discloses a sliding spotlight SAR (synthetic aperture radar) as well as an implementing method and a device thereof. The implementing method of the sliding spotlight SAR comprises steps as follows: the maximum aspect angle and the antenna dimension of the sliding spotlight SAR are calculated on the basis of system parameters of the sliding spotlight SAR; the quantity of antenna subarrays, meeting the requirement of a first condition, of the sliding spotlight SAR is determined; a PRF (pulse repetition frequency) which meets requirements of a second condition and a third condition is determined; wave position information of the sliding spotlight SAR is acquired on the basis of the PRF meeting the requirements of the second condition and the third condition; key parameters of the sliding spotlight SAR are calculated on the basis of the wave position information of the sliding spotlight SAR; and when the key parameters of the sliding spotlight SAR meet the requirements of preset indexes, the quantity of the antenna subarrays of the sliding spotlight SAR is the quantity of the antenna subarrays meeting the requirement of the first condition, and the PRF of the sliding spotlight SAR is the PRF meeting the requirements of the second condition and the third condition. With the adoption of the technical scheme, the key parameters of the sliding spotlight SAR can be effectively designed, so that the sliding spotlight SAR can have higher resolution ratio and larger azimuth width.

An imaging system and method. The invention provides an intra-pulse repetition interval (PRI) agile beam technique for enhanced resolution that can be used at aspect angles near the velocity vector of a host vehicle. It is particularly useful at small scan angles where beam sharpening array times become large. At these scan angles, the bandwidth of the clutter is narrower than at higher scan angles and allows large PRIs without degradation from Doppler ambiguities. In accordance with the present teachings, sequential illumination is performed within a PRI to multiple beam locations using an agile beam. The interleaving of beams reduces map formation times compared to conventional techniques using sequential arrays. The inventive system is adapted for use with an electronically scanned (e.g., synthetic aperture array radar) antenna. The inventive method includes the steps of activating the antenna to generate a beam of electromagnetic energy; causing the beam to scan over a predetermined scan volume consisting of a predetermined range of scan angles relative to a reference vector; and generating multiple simultaneous beams of electromagnetic energy over a subset of the predetermined range of scan angles.

There is disclosed a system and method for detecting targets. A transmitter may transmit a first inverse transform signal, the first inverse transform signal derived from a reference image of a first reference target at a first aspect angle. A receiver may receive a return signal reflected from a scene. A detector may determine, based on the return signal, if an object similar to the first target at the first aspect angle is detected within the scene.

The present invention is directed to a system and method for the identification of a target object in PCL radar applications. The disclosed embodiments describe the systems and methods used in the identification of a target object from the collection of data representing specific target object features, such as velocity, altitude, fuselage length, wing length, or wing sweepback angle, and the comparison of selected target object features with a database of known aircraft features. The present invention also provides for the calculation of feature dimensions, such as the fuselage length, wing length, or wing sweepback angle from measurements associated with a peak signal lobe as a function of a bistatic aspect angle.

A system and method for detection of a target object/material includes identifying a polarimetric signal for a plurality of aspect angles. One/two-dimensional Mueller matrix image or one/two-dimensional Stokes vector image can be processed using power spectral analysis, wavelet and fractal analysis for further image, having increased discrimination with reduced false-ratio. In addition, each of the angular polarization states due to their association with a particular aspect angle are then cross-correlated to generate a two-dimensional image that relates the level of correlation with the aspect angle. Finally, the output information, including statistical parameters are fed to the input of a neural-fuzzy network for further optimization and image enhancement.

The invention discloses a LCD of optical compensation, which comprises the following parts: first base plate, second base plate, liquid crystal layer, the first-phase compensating plate, second-phase compensation plate, optical compensation film, first polarizing plate and second polarizing plate, wherein the liquid crystal array pattern of liquid crystal layer displays optical compensation bent pattern; the first-phase compensating plate is set on the exterior of the first base plate; the second-phase compensation plate is set on the exterior of second base plate; multilayer non-cylinder liquid crystal is contained in the first-phase compensation plate and second-phase compensation plate, which reduces the dark mesh-light of liquid crystal layer; the optical compensation film adapts the single-axle extension delaying-piece on the exterior of the first-phase compensation plate, which reduces the incidence mesh-light of two pieces of orthogonal polarizing plate. The invention improves the LCD comparison and aspect angle effectively.

The present invention discloses a parameter extraction method for a precession target structure. The method is characterized by comprising the steps of respectively acquiring the target radial length information of two radars based on the target one-dimensional range profiles of the two radars; according to the target radial length information, calculating the target radial length curves of the two radars; according to the target radial length curves of the two radars, calculating the target precession angles and the precession axis aspect angle difference of the two radars; according to the target precession angles, the precession axis aspect angle difference of the two radars and the target radial length curves of the two radars; calculating a target length and a target bottom-surface radius. Compared with the prior art, the structure parameters and the precession angles of cooperative targets and non-cooperative targets can be extracted at a relatively accuracy error. Meanwhile, the observation time required for extracting precession characteristics is greatly shortened.

The invention relates to a wide-aspect-angle S-band dual-circular-polarization microstrip antenna for a phased array, and the phased array. The microstrip antenna comprises a top dielectric layer, a central dielectric layer, a bottom dielectric layer, an annular structure located above the top dielectric layer, a rectangular paster and an annular structure which are located on the central dielectric layer, a gap on a ground plate, a first feed line and a second feed line which are located below the bottom dielectric layer. Two ends of the microstrip antenna are respectively connected with a left-hand circular polarization port and a right-hand circular polarization port, wherein the left-hand circular polarization is obtained through the port, and the right-hand circular polarization is obtained through the port. The microstrip antenna has the scanning range of +/-70 degrees, is wide in bandwidth, is large in beam width, is low in width-angle axial ratio, and is simple in structure. The microstrip antenna has two ports, thereby facilitating the free selection of the left-hand circular polarization mode or the right-hand circular polarization mode. The microstrip antenna can be extended to form a large-scale phased array with a random number of antennas.