Abstract: X-band and P-band synthetic aperture radars are used to simultaneously gather swaths of reflected radar data over a specific area simultaneously. The P-band is used to penetrate surface clutter that may be on the top of an ice formation as well as to penetrate an ice mass. X-band is used to map surface clutter on the top of an ice formation as well as to map the top of snow that may appear on an ice formation. Digital elevation maps of the top of the snow or ice clutter, the top of the ice, and the bottom of the ice and or ice thickness are constructed. By summing these various digital elevation maps a measurement of the thickness of sea ice can be determined. Further analysis of DEM, MAG and CRV layers provides an indication of the quality of the ice, for example cracks and pressure ridges, and its weak points.

Abstract: X-band and P-band synthetic aperture radars are used to simultaneously gather swaths of reflected radar data over a specific area simultaneously. The P-band is used to penetrate surface clutter that may be on the top of an ice formation as well as to penetrate an ice mass. X-band is used to map surface clutter on the top of an ice formation as well as to map the top of snow that may appear on an ice formation. Digital elevation maps of the top of the snow or ice clutter, the top of the ice, and the bottom of the ice and or ice thickness are constructed. By summing these various digital elevation maps a measurement of the thickness of sea ice can be determined. Further analysis of DEM, MAG and CRV layers provides an indication of the quality of the ice, for example cracks and pressure ridges, and its weak points.

Abstract: In a method for addressing holograms stored in a plurality of separate storage media, a reference beam is directed to a selected one of the plurality of storage media, the reference beam is then focused so as to obtain a substantially flat wavefront within a reference beam plane of the selected storage medium, and the angle of the reference beam is then varied so as to select a hologram stored therein.

Abstract: In a method for mitigating cross-talk in high-efficiency, angle-multiplexed holograms stored in photorefractive media, a plurality of uniformly low-efficiency holograms are first stored within a common holographic storage medium and then simultaneously exposed to a like plurality of mutually incoherent reference beams. Each reference beam effects enhancement of its corresponding hologram so as to increase the level thereof while also minimizing cross-talk between holograms.

Abstract: A pattern recognition apparatus and a method for operating same. The apparatus includes a volume holographic medium (4) having a plurality of Fourier-space volume holograms representing pattern templates stored within. The apparatus further includes a spatial light modulator (1) and a phase encoder (2). The phase encoder has an output optically coupled to the medium by a first Fourier transform lens (3). The spatial light modulator spatially modulates a spatially uniform laser beam (7) in accordance with an unknown pattern. The two-dimensional phase encoder causes the spatially modulated laser beam to be spatially distributed prior to application to the medium. The apparatus also includes a detector (6, 11) having an input optically coupled by a second Fourier transform lens (5) means to an angular spectrum of plane waves generated by the medium in response to the output of the spatial modulator, phase encoder, and first Fourier lens.

Abstract: Method and apparatus for guiding a projectile to a target in a scene using a scene imaging sensor in which the projectile has a guidance and control system for aiming the projectile. A first tracker analyzes the scene and selects a first track point representative of a target and a first confidence value serving as a reliability measure of the first selected track point. A second tracker analyzes the scene and selects a second track point representing the target and a second confidence value which serves as a reliability measure of the second selected track point. Each of said trackers are constructed and arranged to operate independently in a manner that is substantially statistically uncorrelated with respect to each other. A joint confidence value based on track point proximity, convergence and divergence is generated from the tracker data and a composite confidence index is calculated from the first and second confidence values and the joint confidence value.

Abstract: An automatic target acquisition and tracking system has been developed for a focal plane array seeker. The automatic target acquisition is achieved by three independent target acquisition algorithms, viz., the maximum likelihood classification, the video spatial clustering, and the target-to-interference ratio. Each algorithm operates asynchronously and provides independent target detection results. Target information is then combined hierarchically in a probabilistic fashion and prioritized. The highest priority target is handed off to a dual mode tracker consisting of a minimum absolute difference correlation tracker and a centroid tracker. The dual mode tracker subsequently provides a feedback signal to a proportional navigation system or other guidance/control system for directing the flight path of a munition.

Abstract: In a data compression system utilizing the Haar, Walsh or Hadamard transformation, a machine which operates in the transform domain to obtain approximations to the higher order transform coefficients by means of extrapolation from lower order transform coefficients. The extrapolation of the higher order transform coefficients is approximately equivalent to either a linear or to a quadratic interpolation within the spatial or time domain.

Abstract: A method and apparatus is described for implementing a real time video processing system based on the rationalized Haar transform. The system operates in real time to remove redundant information from video data for the purpose of compressing the video bandwidth. A digital apparatus for implementing the system is described which is capable of processing video in real time at data rates up to 60 M bits per second.

Abstract: A digital machine for detecting and processing pictorial edges in video data. The invention mechanizes, in parallel, three different processing techniques, the outputs of which are combined in a selectable manner to generate processed and enhanced video data. The first parallel processor convolves four inter-related 3.times.3-element masks with the 2-dimensional video input data to locate the pictorial edges, to determine the edge directions, to execute edge connectivity logic, and to calculate certain edge statistics. The second parallel processor implements a 3.times.3 element, low or high pass image filter, and an adaptive threshold filter. Both the first and the second parallel processors use Fast-Form algorithms which allow data processing in real time with a minimum of components. The third parallel processor operates on the video data in serial form to generate the video output from the edge processing unit.

Abstract: A reduction in bandwidth of two-dimensional video data is obtained by the two-dimensional transformation of the video data by means of one of a class of fast transformations followed by the elimination of certain non-significant transform coefficients prior to the transmission of the transform data. The lower-order transform coefficients or "zonal coefficients" which are usually significant in size, are always transmitted. Prior to transmission, parity bits are added to the zonal coefficients to allow error detection. An adaptive filter eliminates from the higher-order transform coefficients, those non-significant transform coefficients of magnitude less than a threshold level, which level is adjusted in response to the amount of data in the buffer memory awaiting transmission so as to transmit the most significant transform coefficients from a succession of two-dimensional data vectors. At the receiving end of the communication link the array of transform coefficients is reconstituted from the received data.

Abstract: A method and apparatus is presented for digitally implementing a class of transforms for the purpose of processing data in real time based on decomposing data vectors into sets of coefficients associated with matrices of transformations in the class with each transform in the class being made up of an ordered cascade of elementary transformations. Each state of the cascade is composed of the product of a weighting transformation (diagonal weighting matrix) and a generating transformation (sparse matrix composed of +1, -1, and zero elements). The inverse generating transform is obtained as the adjoint of the generating transform (transpose of the generating matrix).The invention is implemented by cascading one or more modules composed of adder/subtractors, delays, and multipliers with all modules having the same structure and the number of modules at any stage being twice the number in the preceding stage.