Abstract: According to embodiments, a radar system includes: at least one radio receiver which is comprised of: an antenna configured to receive RF data including both the direct-path RF signal transmitted from a radio transmitter and a reflected RF signal when the transmitted RF signal is reflected from the target; a memory configured to store the same predetermined RF waveform profile data used by the transmitter to generate and transmit the RF signal; a timing unit to provide timing; a matched filter application configured to generate and apply a matched filter for identifying RF signal signatures in RF data; and one or more processors configured to: (i) analyze the received RF data to identify multiple, repeated, individual RF signals corresponding to the direct-path transmitted RF signal; (ii) split the identified RF signals corresponding to the direct-path transmitted RF signal into a plurality of repeating units each having an interval time; (iii) create a matched filter using the predetermined transmit waveform

Abstract: Apparatus and method configured to determine locations of man-made objects within synthetic aperture radar (SAR) imagery. The apparatus and method prescreen SAR imagery to identify potential locations of man-made objects within SAR imagery. The potential locations are processed using a change detector to remove locations of natural objects to produce a target image containing location of substantially only man-made objects.

Abstract: Method and apparatus for detecting and characterizing a pulse sequence using a finite impulse filter to determine a pulse width (PW) of pulses within the pulse sequence. The method and apparatus may also apply a histogram to the filtered pulses to determine the pulse rate interval (PRI) of pulses in the pulse sequence.

Abstract: Apparatus and method configured to determine locations of man-made objects within synthetic aperture radar (SAR) imagery. The apparatus and method prescreen SAR imagery to identify potential locations of man-made objects within SAR imagery. The potential locations are processed using a change detector to remove locations of natural objects to produce a target image containing location of substantially only man-made objects.

Abstract: According to embodiments, a radar system includes: at least one radio receiver which is comprised of: an antenna configured to receive RF data including both the direct-path RF signal transmitted from a radio transmitter and a reflected RF signal when the transmitted RF signal is reflected from the target; a memory configured to store the same predetermined RF waveform profile data used by the transmitter to generate and transmit the RF signal; a timing unit to provide timing; a matched filter application configured to generate and apply a matched filter for identifying RF signal signatures in RF data; and one or more processors configured to: (i) analyze the received RF data to identify multiple, repeated, individual RF signals corresponding to the direct-path transmitted RF signal; (ii) split the identified RF signals corresponding to the direct-path transmitted RF signal into a plurality of repeating units each having an interval time; (iii) create a matched filter using the predetermined transmit waveform

Abstract: Apparatus for augmenting a received signal comprising a receiver configured to receive a signal, a digitizer configured to generate a digitized version of the received signal at two different times, and a signal processor, coupled to the digitizer, configured to determine a phase relationship between the digitized signals at the two different times, adjust a phase of at least one of the digitized signals based on the phase relationship to combine the two digitized signals to form an augmented signal.

Abstract: Embodiments of the present invention implement a novel methodology for processing radar image data from a radar system having one or more transmitter and receiver antenna pairs. The novel methodology deliberately operates on spectrally-notched radar data. It uses a specially-adapted version of the CLEAN algorithm to mitigate the effects of frequency-band notching. Following that, it performs a non-linear sidelobe-reduction algorithm to further eliminate artifacts and produce radar imagery of much higher quality. In some cases, it exploits a specific version of the recursive sidelobe minimization (RSM) algorithm which operates in the frequency and aperture (spatial) domain.

Abstract: A spectrum sensing radar system including a spectrum power sensing module configured to sense electromagnetic signal powers in a plurality of sub-frequencies and generate a sensed power set including a plurality of sensed electromagnetic signal powers corresponding to each of the plurality of sub-frequencies; a multi-objective function module configured to receive the sensed power set and calculate a first objective function for each of the plurality of sub-frequencies, wherein the first objective function includes a power function divided by an empirical measure of interference of the sensed power set to form a signal plus noise objective function for a sub-frequency of the plurality of sub-frequencies, and wherein the power function further includes a peak transmit power of the radar system multiplied by a gain of an antenna of the radar system, multiplied by a wavelength of a carrier of the sub-frequency.

Abstract: Embodiments of the present invention concern locating targets using non-linear radar with a matched filter which uses exponential value of the transmit signal. According to embodiments, a method of non-linear radar target location includes: transmitting a signal of a transmit waveform towards a target; receiving a signal from the target; creating a matched filter by generating an exponential function of the transmit waveform corresponding to a particular harmonic of the interest; and applying the matched filter to the received signal to generate and output a signature waveform for the target of the particular harmonic of interest. In other embodiments, the matched filtering may be combined with sidelobe reduction.

Abstract: Method for determining distance to target using a multitone nonlinear radar system comprising providing a transmitter that transmits a signal comprising at least two predetermined frequency components; receiving transmitted signal upon reflection from target; determining the phase relationships of the frequency components when signal strikes target; determining distance the signal has travelled to target based upon the phase relationship of the frequency signal components at the time of reflection from target; computing the distance to target.

Abstract: Embodiments of the present invention implement a novel methodology for processing radar image data from a radar system having one or more transmitter and receiver antenna pairs. The novel methodology deliberately operates on spectrally-notched radar data. It uses a specially-adapted version of the CLEAN algorithm to mitigate the effects of frequency-band notching. Following that, it performs a non-linear sidelobe-reduction algorithm to further eliminate artifacts and produce radar imagery of much higher quality. In some cases, it exploits a specific version of the recursive sidelobe minimization (RSM) algorithm which operates in the frequency and aperture (spatial) domain.

Abstract: A method for optimizing bandwidth selection of a radar transmission in a frequency bandwidth in which the frequency bandwidth is divided into a plurality of sub-bands having a plurality of different bandwidths. The energy level is measured for each sub-band and a range resolution is also determined for each sub-band. Thereafter, a sub-band is selected in the frequency range where the signal to interference plus noise ratio plus the range resolution is maximum. Thereafter, a radar transmission is transmitted in the selected sub-band with a bandwidth corresponding to the bandwidth of the selected sub-band.

Abstract: A spectrum sensing radar system including a spectrum power sensing module configured to sense electromagnetic signal powers in a plurality of sub-frequencies and generate a sensed power set including a plurality of sensed electromagnetic signal powers corresponding to each of the plurality of sub-frequencies; a multi-objective function module configured to receive the sensed power set and calculate a first objective function for each of the plurality of sub-frequencies, wherein the first objective function includes a power function divided by an empirical measure of interference of the sensed power set to form a signal plus noise objective function for a sub-frequency of the plurality of sub-frequencies, and wherein the power function further includes a peak transmit power of the radar system multiplied by a gain of an antenna of the radar system, multiplied by a wavelength of a carrier of the sub-frequency.

Abstract: A method for optimizing bandwidth selection of a radar transmission in a frequency bandwidth in which the frequency bandwidth is divided into a plurality of sub-bands having a plurality of different bandwidths. The energy level is measured for each sub-band and a range resolution is also determined for each sub-band. Thereafter, a sub-band is selected in the frequency range where the signal to interference plus noise ratio plus the range resolution is maximum. Thereafter, a radar transmission is transmitted in the selected sub-band with a bandwidth corresponding to the bandwidth of the selected sub-band.

Abstract: Embodiments of the present invention concern locating targets using non-linear radar with a matched filter which uses exponential value of the transmit signal. According to embodiments, a method of non-linear radar target location includes: transmitting a signal of a transmit waveform towards a target; receiving a signal from the target; creating a matched filter by generating an exponential function of the transmit waveform corresponding to a particular harmonic of the interest; and applying the matched filter to the received signal to generate and output a signature waveform for the target of the particular harmonic of interest. In other embodiments, the matched filtering may be combined with sidelobe reduction.

Abstract: Embodiments of the present invention relate cognitive radar and RF technologies, and more particularly, to spectrum sensing processing for rapidly monitoring the RF spectrum for channel availability and activity. The goal is to find and use unoccupied RF channels to broadcast and receive information. According to one embodiment, a method for analyzing a received RF signal to determine unused channels, or frequencies, therein, comprises: analyzing a received RF signal to determine anchor points that represent high energy frequency locations; calculating distances between the determined anchor points; identifying and eliminating clusters or isolated anchor points defined as a high energy region of interference based on the calculated distances; and selecting at least one remaining unoccupied frequency for transmitting or receiving a RF signal.

Abstract: Method for determining distance to target using a multitone nonlinear radar system comprising providing a transmitter that transmits a signal comprising at least two predetermined frequency components; receiving transmitted signal upon reflection from target; determining the phase relationships of the frequency components when signal strikes target; determining distance the signal has travelled to target based upon the phase relationship of the frequency signal components at the time of reflection from target; computing the distance to target.

Abstract: A method and system for forming an image comprising at least one processor for performing the following: initializing an N by P image array IO by setting all values to a large number; inputting at least one image frame; randomly selecting and removing a subset of pixel locations from the total number of available pixel locations to form a preliminary image array IC; for each pixel location comparing the complex magnitude of each pixel in the image array IO with the magnitude of the corresponding pixel in image array IC, and if the pixel value in the image array IC is smaller than the corresponding pixel in the image array IO or if the IC value equals 0, then the current pixel value in image array IO is replaced by the pixel value in the image array IC; and repeating for a number of iterations to form an image.

Abstract: Embodiments of the present invention relate cognitive radar and RF technologies, and more particularly, to spectrum sensing processing for rapidly monitoring the RF spectrum for channel availability and activity. The goal is to find and use unoccupied RF channels to broadcast and receive information. According to one embodiment, a method for analyzing a received RF signal to determine unused channels, or frequencies, therein, comprises: analyzing a received RF signal to determine anchor points that represent high energy frequency locations; calculating distances between the determined anchor points; identifying and eliminating clusters or isolated anchor points defined as a high energy region of interference based on the calculated distances; and selecting at least one remaining unoccupied frequency for transmitting or receiving a RF signal.

Abstract: A system and method for locating a moving target behind a wall or barrier comprising: providing a plurality of images of the region of interest; selecting a reference image from the plurality of images; forming a predetermined number of difference images by subtracting the absolute value of the pixels of the reference image from the absolute values of pixels in a predetermined number of the plurality of images; eliminating negative pixel values in the predetermined number of difference images; minimizing the side lobes to form a combined difference image for each reference frame, selecting another reference image from the plurality of images and performing the steps of forming a plurality of difference images, eliminating negative pixel values, averaging the resulting predetermined number of difference images and minimizing the side lobes for each selected reference image to form a set of combined difference images which contain the moving target signature.