Abstract: A method and system for restoring a GPS signal is provided. The method including the steps of receiving a target location, receiving location of visible satellites, calculating a transmit delay, calculating a Doppler offset, calculating a chipping offset, computing navigating data and PRN codes, formulating signals using the transmit delay, Doppler offset, chipping offset, navigation data and PRN codes, and transmitting the formulated signal.

Abstract: A method of processing a radar hit from an object using, for each of a plurality of cells, a signal strength threshold, a hit rate threshold, a time of last detection; and receiving, for one of the plurality of cells corresponding to the object, a measured signal strength, a measured hit rate and a time of measurement. The object is identified as clutter if the measured hit rate is greater than the hit rate threshold, and the measured signal strength is less than signal strength threshold. The signal strength threshold is above a conventional CFAR signal threshold. Measured Doppler strength may also be used to identify clutter. Identification can be determined using Doppler-polarity-specific data values. The hit rate and the mean Doppler speed of the one of the plurality of cells can be updated using a running average.

Abstract: A method of processing a radar hit from an object using, for each of a plurality of cells, a signal strength threshold, a hit rate threshold, a time of last detection; and receiving, for one of the plurality of cells corresponding to the object, a measured signal strength, a measured hit rate and a time of measurement. The object is identified as clutter if the measured hit rate is greater than the hit rate threshold, and the measured signal strength is less than signal strength threshold. The signal strength threshold is above a conventional CFAR signal threshold. Measured Doppler strength may also be used to identify clutter. Identification can be determined using Doppler-polarity-specific data values. The hit rate and the mean Doppler speed of the one of the plurality of cells can be updated using a running average.

Abstract: Methods and systems for detecting chemical and biological agents using oligonucleotide aptamers. A sensor includes a detection aptamer that has a binding domain for the chemical or biological agent, and is bound to fibers of a textile such as a patch or article of clothing. The detection aptamer can be stabilized and enhanced through a stabilization agent such as trehalose or through binding to a nanoparticle which is then bound to the fiber. Binding of the chemical and biological agent of interest to the detection aptamer can be reported to the user or wearer of the textile in a variety of ways, including visually and electrically.

Abstract: Processing of MIMO radar data generated from overlapped MIMO arrays. The method of virtualizing (basebanding the MIMO phase centers) allows for processing without the need to omit content/information/energy from overlapped virtual elements.

Abstract: The present invention is directed to an antenna system and a method that is configured to compute calibration element voltage gain patterns as functions of a digital antenna model and a plurality of complex beamformer voltages, determine calibration through path transfer functions from the plurality of complex voltages, and remove the calibration element voltage gain patterns from the calibration through path transfer functions to determine a beamforming network transfer function. The beamforming network transfer function and the far-field element voltage gain patterns are combined to obtain a system transfer function used to revise a calibration table.

Abstract: The present invention is directed to a method for processing radar signals in a distributed array radar that includes a first airborne platform and at least one second airborne platform. Doppler filtered radar return samples are obtained and a weight value is calculated as a function of first clutter signals and second clutter signals. The weight value is employed in a weight vector that is computed, as well, from a steering vector that need not be matched to the target vector. The weight vector is applied to a signal vector corresponding to the Doppler filtered radar return samples. An open loop feedback is implemented and configured to create beam pattern nulls at angles corresponding to the plurality of first interference signals within each of the Doppler bins without substantially tracking a position or velocity of the first airborne platform or the at least one second airborne platform.

Abstract: A portable radar system is disclosed including a mast, a fabric enclosure being sized and dimensioned to be extendable in a covering relation with at least part of the mast; and an antenna comprising at least one element, wherein said antenna is arranged on the fabric enclosure and is positioned to illuminate or receive reflections from a target when the fabric enclosure is in a covering relation with the mast and the mast is deployed.

Abstract: A method for authenticating an item of interest. A nucleic acid tag comprised of a nucleotide-support platform attached to a first nucleic acid molecule is added to the item of interest, where information about the item of interest is contained within the first nucleic acid molecule. A portion of an item is sampled for the presence of the nucleic acid tag, where the item is potentially the item of interest. The presence of the nucleic acid tag is detected in the sample, where the presence of the first nucleic acid tag authenticates the item as the item of interest.

Abstract: A radar architecture comprising a computing device having a DC subtraction module, programmed to average a first value of a first pixel from a first received SAR image and a second value of a second pixel from a second received SAR image, to produce an averaged value, and to subtract the averaged value from the first value, resulting in a first DC subtracted pixel value, and to subtract the averaged value from the second value, resulting in a second DC subtracted pixel value; a DFT processing module programmed to receive the first DC subtracted pixel value and the second DC subtracted pixel value and to output a first DFT output comprising a plurality Doppler bins; and a detector module programmed to determine if the output of the DFT represents the presence of a target, and to estimate range-rate via a lookup table.

Abstract: The present invention relates to a method and system for identifying and eliminating second time-around ambiguous targets and, more particularly, to a method and system for identifying and eliminating second time-around ambiguous targets using waveform phase modulation.

Abstract: A radar system located on an antenna array mounted on a moving carrier and including plurality of antenna elements; a transmitter portion coupled to the antenna and configured to transmit a plurality of transmit beams, each including a corresponding orthogonal transmit waveform of a plurality of orthogonal transmit waveforms, each of the plurality of transmit beams having a transmit phase center spatially located at a respective point along the antenna array, the transmitter portion being configured to transmit each transmit beam during at least a portion of a pulse repetition interval, wherein the transmitter portion is configured to shift the transmit phase center of each transmit beam for each pulse repetition interval to a respective point along the antenna array in a direction opposite the movement of the carrier, such that a speed of the respective transmit phase center of each beam remains is reduced.

Abstract: A transmit-receive radar system having multiple sub-apertures aligned in an offset, off-centered cross pattern that allows for searching of a sub-aperture pattern for the peak response without having to retransmit beams. The placement of the physical apertures combined with the use of MIMO operations provides a non-uniform distribution of virtual sub-apertures that suppresses ambiguous grading lobes and maintains angle resolution in a manner equivalent to that of non-MIMO approaches. As a result, target detection is enabled within a significantly larger angular area than in a non-MIMO configuration.

Abstract: A method and system for restoring a GPS signal is provided. The method including the steps of receiving a target location , receiving location of visible satellites, calculating a transmit delay, calculating a Doppler offset, calculating a chipping offset, computing navigating data and PRN codes, formulating signals using the transmit delay, Doppler offset, chipping offset, navigation data and PRN codes, and transmitting the formulated signal.

Abstract: A radar system includes an image forming circuit that provides a two-dimensional image of an operating environment. The image includes pixel elements representative of the operating environment. The system includes at least one filter configured to convert the two-dimensional image into a clutter classification map of clutter regions. A predetermined number of clutter regions are selected as training cells for a predetermined cell-under-test (CUT). A space-time adaptive processor (STAP) is configured to derive a weighted filter from training cell data. The STAP applies the weighted filter to a digital return signal associated with the predetermined CUT to provide a STAP-filtered digital return signal having the clutter signal components substantially eliminated therefrom.

Abstract: A method and system for restoring a GPS signal is provided. The method including the steps of receiving a target location, receiving location of visible satellites, calculating a transmit delay, calculating a Doppler offset, calculating a chipping offset, computing navigating data and PRN codes, formulating signals using the transmit delay, Doppler offset, chipping offset, navigation data and PRN codes, and transmitting the formulated signal.

Abstract: A system and method for mitigating multipath propagation are disclosed herein. The method may include collecting a plurality of detections of a target, forming a plurality of models each assuming at least one parameter causing multipath propagation, determining which model best fits the detections of the target, using the best fit model to approximate the ground conditions, and using the approximated ground conditions to remove the multipath error from the observed signals.

Abstract: A system and method for phased-array radar that is capable of accurate phase-only steering at any unambiguous angle is provided. In various embodiments, system and method that compensates for the varying effective element spacing of phased array radar, which occurs as a result of transmitting a wideband signal with phase shifters operating at a fixed phase, by interpolating and resampling across all elements, per frequency, to generate a desired effective spacing between the elements.

Abstract: A spiral antenna, comprising a first arm and a second arm. The first arm and second arm are interlaced with each other. Each arm has a plurality of turns comprising an inner subset of circular turns, and an outer subset of turns, electrically coupled to the inner subset, having a shape with only four lines of symmetry. An array of such spiral antennas disposed a substrate that extends in a direction of a longitudinal axis and having a round cross section in a plan transverse to the longitudinal axis.

Abstract: A target is located and a track is associated with the target in the fusion coordinate system. An estimate/prediction of the target's velocity is developed within the tracker, as well as , a vector representing the distance from the fusion center to the target as estimated by the tracker, and , a vector representing the known distance from the fusion center to the sensor. The sensor's range vector, (the distance from the sensor to the target as predicted by the tracker) is transformed to fusion coordinates. Using the sensor's range vector, normalized to unit length, in fusion coordinates and the estimated target's velocity, an estimate of the target's speed projected in the direction of is derived. The estimated range-rate is compared per update to the sensor's measured range-rate in the form of an error measurement. The error is then used to correct the track's velocity prediction.