Abstract: A horn antenna comprises an electrically conductive shell having an inner surface, a cavity formed in the shell, an aperture defined at one end of the cavity, a throat section coupled to the electrically conductive shell in communication with another end of the cavity opposite the aperture, and a spatially and frequency dependent radio frequency (RF) attenuator disposed within the cavity, such that an attenuation of RF energy propagating through the cavity between the throat section and the aperture more rapidly increases in an outward direction towards the inner surface of the electrically conductive shell as the frequency of the RF energy increases.

Abstract: A compact test range system for testing an article located within a test zone comprises a reflector defining a surface and a focus, a feed horn configured to emit radio waves, one or more processors, and a memory coupled to the processor. The radio wave includes an infinite number of rays, where the rays of the radio wave include an uppermost ray, a middle ray, and a lowermost ray directed towards the surface of the reflector. The memory stores data comprising a database and program code that, when executed by processors, causes the compact range test system to receive as input a plurality of field tilt angles. In response to receiving the field tilt angles, the system determines three points of intersection between the uppermost radio wave, the middle radio wave, and the lowermost radio wave that correspond to a first test position.

Abstract: A compact test range system for testing an article located within a test zone comprises a reflector defining a surface and a focus, a feed horn configured to emit radio waves, one or more processors, and a memory coupled to the processor. The radio wave includes an infinite number of rays, where the rays of the radio wave include an uppermost ray, a middle ray, and a lowermost ray directed towards the surface of the reflector. The memory stores data comprising a database and program code that, when executed by processors, causes the compact range test system to receive as input a plurality of field tilt angles. In response to receiving the field tilt angles, the system determines three points of intersection between the uppermost radio wave, the middle radio wave, and the lowermost radio wave that correspond to a first test position.

Abstract: A horn antenna comprises an electrically conductive shell having an inner surface, a cavity formed in the shell, an aperture defined at one end of the cavity, a throat section coupled to the electrically conductive shell in communication with another end of the cavity opposite the aperture, and a spatially and frequency dependent radio frequency (RF) attenuator disposed within the cavity, such that an attenuation of RF energy propagating through the cavity between the throat section and the aperture more rapidly increases in an outward direction towards the inner surface of the electrically conductive shell as the frequency of the RF energy increases.

Abstract: A system for performing radar cross section measurements of a target may include a radar system and an antenna associated with the radar system to transmit signals and to receive reflected signals from the target and a clutter source. An EM tagging device is locatable proximate to the clutter source to spectrally tag the clutter source by causing changes in an electromagnetic signal reflected by the clutter source when a predetermined radar signal transmitted by the radar system is incident on the target, the clutter source and the EM tagging device. A module may identify a spectrally tagged component of reflected signals received by the radar system from the target, the clutter source and the EM tagging device.

Abstract: A system for performing radar cross section measurements of a target may include a radar system and an antenna associated with the radar system to transmit signals and to receive reflected signals from the target and a clutter source. An EM tagging device is locatable proximate to the clutter source to spectrally tag the clutter source by causing changes in an electromagnetic signal reflected by the clutter source when a predetermined radar signal transmitted by the radar system is incident on the target, the clutter source and the EM tagging device. A module may identify a spectrally tagged component of reflected signals received by the radar system from the target, the clutter source and the EM tagging device.

Abstract: A system for performing radar cross section measurements of a target may include a radar system and an antenna associated with the radar system to transmit signals and to receive reflected signals from the target and a clutter source. An EM tagging device is locatable proximate to the clutter source to spectrally tag the clutter source by causing changes in an electromagnetic signal reflected by the clutter source when a predetermined radar signal transmitted by the radar system is incident on the target, the clutter source and the EM tagging device. A module may identify a spectrally tagged component of reflected signals received by the radar system from the target, the clutter source and the EM tagging device.

Abstract: Systems and methods enable numerically creating a flat field in a compact radar range with a curved reflector, and without use of a separate phased array of elements, at frequencies lower than those that are possible with currently known, reflector-only compact radar ranges. A compact radar range is calibrated to enable weighting factors to be computed. The weighting factors may be computed by performing an optimization algorithm. The weighting factors are used to weight separate target signals sequentially returned from a target zone such that, when combined, a numerically composite measurement has a substantially constant magnitude across the target zone.

Abstract: A method, apparatus, and computer readable medium are provided for creating a quantitative, three-dimensional representation of a surface of a human subject. Data representing a physical appearance of a human subject is gathered using inverse synthetic aperture radar. A source signal is directed toward the human subject as the target rotates through a range of motion and a return signal is collected. The returned signal is transformed into a quantitative representation of the surface data. The quantitative representation can be added to an archive or can be checked against an archive to determine if the human target is indexed in the archive.

Abstract: A method, apparatus, and computer readable medium are provided for creating a quantitative, three-dimensional representation of a surface of a human subject. Data representing a physical appearance of a human subject is gathered using inverse synthetic aperture radar. A source signal is directed toward the human subject as the target rotates through a range of motion and a return signal is collected. The returned signal is transformed into a quantitative representation of the surface data. The quantitative representation can be added to an archive or can be checked against an archive to determine if the human target is indexed in the archive.