US Government As Represented by the Secretary of the Army

Anthony Frank Martone

Kenneth Irving Ranney

Gregory James Mazzaro

Kyle Alexander Gallagher

Kelly D Sherbondy

Lam Huy Nguyen

Traian V Dogaru

Roberto Innocenti

Calvin Duc Le

Abigail S Hedden

David M McNamara

A method and system for providing a cooperative spectrum sharing model that jointly optimizes primary user equipment parameters for improved frequency agility and performance while mitigating mutual interference between the primary user equipment and secondary user equipment. Spectrum sensing is implemented to form a power spectral estimate of the electromagnetic environment (EME) and apply multi-objective optimization to adjust the operational parameters of the primary user equipment to mitigate interference.

Method and system for optimizing transceiver spectrum sharing

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.

Spectrum sensing for advanced radar performance

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.

Methods and systems for locating targets using non linear radar with a matched filter which uses exponential value of the transmit signal

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. A system comprising a transmitter subsystem that transmits radar signal comprising at least two frequency components; a receiver subsystem configured to receive a return signal comprising intermodulation and harmonic products; at least one processor configured to extract frequency samples from the return signal within a frequency range, apply a window function to the extracted frequency samples and perform an inverse fast Fourier transform on the resulting function to create a range profile.

Multitone radar with range determination and method of use

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.

Method and apparatus for bandwidth selection for radar transmission

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. The method may further include performing an optional quality or risk assessment on remaining frequencies of the waveform, and eliminating high risk frequencies from consideration in some instances.

Fast method for wideband spectrum sensing

A method and apparatus for cognitive non-linear radar processing comprising identifying one or more frequency bands of interest, passively scanning, using a non-linear radar (NR), the one or more frequency bands of interest to determine whether interference signals are occupying the one or more bands, transmitting radar waveforms and receiving radar waveform responses at one or more frequency bands determined to be free of interference, determining a likelihood of a target being present or not based on whether the received waveform responses match stored waveform responses for non-linear targets, and modifying waveform parameters of the transmitted radar waveform when the received waveform responses match the stored waveform responses, so as to transmit a modified radar waveform.

Method and apparatus for cognitive nonlinear radar

A multitone nonlinear radar system (and a method of operating such a system) comprising a transmitter that transmits a signal comprising at least two predetermined frequency components; a receiver operating to receive return signals comprising harmonics of at least two predetermined frequencies, combinations of the at least two predetermined frequency components, and combinations of the harmonics of the at least two predetermined frequency components that are within a predetermined selected frequency range that has been predetermined to enable detection and/or classification of an electronic device; at least one antenna operating to transmit and receive electromagnetic radiation operatively connected to the transmitter and receiver; the receiver comprising at least one high pass filter for attenuating linear reflections at the two predetermined frequencies, and an analyzer; whereby electronic devices may be detected and identified by analyzing return signals within a predetermined frequency range.

Multitone harmonic radar and method of use

A method and system for forming an image comprising at least one processor for performing the following: initializing an N by P image array Iby 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 I; for each pixel location comparing the complex magnitude of each pixel in the image array Iwith the magnitude of the corresponding pixel in image array I, and if the pixel value in the image array Iis smaller than the corresponding pixel in the image array Ior if the Ivalue equals 0, then the current pixel value in image array Iis replaced by the pixel value in the image array I; and repeating for a number of iterations to form an image.

Target detection utilizing image array comparison

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.

Change detection method and system for use in detecting moving targets behind walls, barriers or otherwise visually obscured

A system and method of detecting moving targets comprises transmitting electromagnetic waves rays from a plurality of transmitters at sequential; receiving reflected waves into a plurality of receivers after each transmission; the compilation of the reflected waves from the plurality of receivers for each transmission representing a data frame; forming a signal that monitors changes between the two sets of frames; at least one processor operating to process and compare frames; forming a difference image using a back-projection algorithm; scanning the difference image using a constant false alarm rate (CFAR) window; the CFAR window scanning the entire difference image and identifying a list of points of interest and eliminating the sidelobe artifacts present in the difference image thereby creating CFAR images; processing the CFAR images using morphological processing to create a morphological image; determining the number of clusters present in the morphological image; using K-means clustering to indicate the centroid of each cluster; and tracking using a Kalman filter. The system comprises a plurality of M transmitters, a plurality of receivers, and at least one memory, the transmitters operating in sequence to transmit electromagnetic waves rays sequentially; the receivers receiving reflected waves after each transmission; the compilation of the reflected waves from the plurality of receivers for each transmission representing a data frame; at least one processor operating to perform the method.

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Ellicott City, MD, United States of America

Anthony Frank Martone