Raytheon Company

Hughes Electronics Corporation

Robert T Frankot

David M Doria

A method of predicting a target type in a set of target types from at least one image is provided. At least one image is obtained. A first and second set of confidence values and associated azimuth angles are determined for each target type in the set of target types from the at least one image. The first and second set of confidence values are fused for each of the azimuth angles to produce a fused curve for each target type in the set of target types. When multiple images are obtained, first and second set of possible detections are compiled corresponding to regions of interest in the multiple images. The possible detections are associated by regions of interest. The fused curves are produced for every region of interest. In the embodiments, the target type is predicted from the set of target types based on criteria concerning the fused curve.

Fusion for automated target recognition

Signal processing methods useful in single-antenna multiple-pass interferometric synthetic aperture radars. The signal processing methods compute an initial elevation estimate from the phase difference between a pair of images (A , A ) with a relatively small elevation angle difference (i.e., a short interferometric baseline) and uses it to initialize the elevation estimation process for pairs of images (A , A ) with longer interferometric baselines. The method may be used to process images that are coherent, or not necessarily mutually coherent. The outputs of the methods comprise a terrain elevation map that mitigates for atmospheric error and a turbulence map.

Method for mitigating atmospheric propagation error in multiple pass interferometric synthetic aperture radar

A family of multiple scale adaptive filters and filtering methods that automatically adapt their impulse response width to local data characteristics, optimizing the accuracy, yield, and/or detail of interferometric measurements. A prefilter with fixed impulse response width is applied to a complex interferogram. The phase of the prefiltered complex interferogram is unwrapped. Then, a weighted combination of the phase-unwrapped, fixed-filtered interferograms is computed using a data-dependent criterion function. The resulting weighting function at each resolution element is typically a nonlinear function of interferogram magnitude and coherence for each fixed filter output at that resolution element.

Averaging-area-constrained adaptive interferometric filter that

A method of computing and correcting phase errors due to atmospheric turbulence in a dual-antenna multiple-pass synthetic array radar (SAR) interferometer system. The method improves topographic mapping accuracy at very long ranges. The method computes an atmospheric correction from the residual phase difference between a two-pass interferometer output (containing atmospheric phase errors) and a dual-antenna single-pass interferometer output (for which atmospheric phase errors cancel because the two channels are collected simultaneously). The residual phase measured in a single resolution element is then filtered by averaging over an area of many resolution elements, typically on the order of several thousand resolution elements. This exploits the long correlation distance of the atmospheric phase errors to reconstruct the dominant low-frequency part of the error spectrum. In addition, unwrapping the phase of the output of the complex Wiener filter produces an atmospheric turbulence measurement map.

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Tucson, AZ, United States of America

Robert T Frankot