Abstract: An antenna apparatus includes an aperture antenna. The antenna apparatus also includes a compact polarimetric monopulse waveguide antenna feed configured to communicate with the aperture antenna. Optionally, the compact polarimetric monopulse waveguide antenna feed includes a monopulse antenna feed configured to communicate with the aperture antenna. The compact polarimetric monopulse waveguide antenna feed also includes a compact polarimetric monopulse feed network configured to communicate with the monopulse antenna feed.

Abstract: An antenna apparatus includes an aperture antenna. The antenna apparatus also includes a compact polarimetric monopulse waveguide antenna feed configured to communicate with the aperture antenna. Optionally, the compact polarimetric monopulse waveguide antenna feed includes a monopulse antenna feed configured to communicate with the aperture antenna. The compact polarimetric monopulse waveguide antenna feed also includes a compact polarimetric monopulse feed network configured to communicate with the monopulse antenna feed.

Abstract: A method and system for determining bending angle and/or the presence of atmospheric ducting on a moving vehicle, including receiving a first GPS signal from a first GPS satellite having an apparent position less than 10 degrees above the horizon; determining a true position of the first GPS satellite from information encoded in the first GPS signal; the first and second antennae receiving GPS signals from a plurality of GPS satellites located more than 15 degrees above the horizon; determining an orientation of a baseline between the first and second antennae based on a phase difference of a carrier frequency of the GPS signals from a plurality of GPS satellites positioned at least 15 degrees above the horizon; determining an apparent position of the first GPS satellite from the first GPS signal and the baseline orientation; and determining the bending angle by calculating the difference between the elevation angle of the apparent position and the elevation angle of the true position of the first GPS satelli

Abstract: A method and system for determining a bending angle and/or the presence of atmospheric ducting. An array of antennas is used in order to form an interferometer. The interferometer receives signals from GPS satellites and uses the index of infraction in order to determine a bending angle of the GPS signals and/or the presence of atmospheric ducting.

Abstract: A method for exploiting the nonlinear structure of hyperspectral imagery employs a manifold coordinate system that preserves geodesic distances in the high-dimensional hyperspectral data space. Data representing physical parameters such as a scene is divided into a set of smaller tiles. The manifolds derived from the individual tiles are then aligned and stitched together to complete the scene. Coordinates are derived for a very large although not complete representative subset of the data termed the “backbone”. Manifold coordinates are derived for this representative backbone and then the remaining samples inserted into the backbone using a reconstruction principle using the property of local linearity everywhere on the manifold to reconstruct the manifold coordinates for the samples not originally belonging to the backbone. The output is a global manifold coordinate system, which for topographical image data depicts clearer detail of land and water portions of a scene.

Abstract: A method and system for determining a bending angle and/or the presence of atmospheric ducting. An array of antennas is used in order to form an interferometer. The interferometer receives signals from GPS satellites and uses the index of infraction in order to determine a bending angle of the GPS signals and/or the presence of atmospheric ducting.