US Government As Represented by the Secretary of the Army

Kyle Alexander Gallagher

Kenneth Irving Ranney

Gregory James Mazzaro

Anthony Frank Martone

Stephen Dorn Freeman

Kelly D Sherbondy

Abigail S Hedden

Kwok Foo Tom

John C Merritt, Iv

Roger P Cutitta

Daniel T Galanos

Edward A Viveiros, Jr

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 (stored in memory) and apply the matched filter to each of repeating units to provide (a) a plurality of direct-path transmitted RF signal arrival times; and (b) a plurality of reflected RF signal arrival times; (iv) adjust relative arrival times and phases of the repeating units of the direct-path transmitted RF signal; and (v) generate radar data from the reflected RF signal further using the adjusted times and phases for arrival times of the repeating units of the direct-path transmitted RF signal.

Asynchronous, coherent, radar transmitter-receiver system

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 method and apparatus for receiving signals from an unknown transmitting source and providing the location of the unknown transmitting source comprising a series of channels for receiving signals radiated by the unknown transmitting sources, generating preprocessed time domain data and generating a SAR image depicting a location of the unknown transmitting source, and a processor for processing the preprocessed time domain data to enhance a pixel value at each pixel location within the SAR image by summing signal data from each channel related to each pixel location to generate an enhanced SAR image.

Method and apparatus for providing a passive transmitter based synthetic aperture radar

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.

Method and apparatus for performing signal augmentation

A radar assembly for receiving signals at spaced frequencies from an unknown transmitting source comprising a receiver operative to receive signals; the receiver comprising a series of channels, each channel comprising a low pass filter configured to allow passage of a signal from an unknown transmitting source, an analog to digital converter configured to transform the signal from the unknown transmitting source to a digital signal, a Hilbert transform configured to transform the digital signal from the unknown transmitting source into a single sideband signal, a Fourier transform configured to transform the single sideband signal into a plurality of regularly spaced frequency samples, and an inverse Fourier transform for extracting regularly spaced frequency samples; whereby extracted pulses form a train of pulses that are inputted into an imager which utilizes synthetic aperture radar to form an image of the area of interest containing the unknown transmitting device and method thereof.

Passive non-linear synthetic aperture radar and method thereof

A method and apparatus for detecting an object comprising a radio frequency transmitter for transmitting a radio frequency signal towards an object; an acoustic signal transmitter for transmitting an acoustic signal capable of causing intermittent contact of conductive and/or semi-conductive junctions of the object; and a radio frequency receiver for receiving the radio frequency signal after the radio frequency signal is reflected from the object, where the received radio frequency signal has been altered by the intermittent contact of conductive and/or semi-conductive junctions of the object.

Method and apparatus for detecting objects using a combination of radio and acoustic signals

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 novel methodology for automatically linearizing a harmonic radar transmitter&#x2014;termed Feed-Forward Filter Reflection (FFFR)&#x2014;is disclosed. The method combines the reflected second harmonic from a filter with the signal passing directly through the filter. The second harmonic from these two paths are combined with equal and opposite amplitudes to reduce the second harmonic beyond filtering alone. This methodology has been experimentally verified at transmit frequencies between 800 and 1000 MHz. Implemented properly, the technique provides greater than 100 dB rejection between 1.6 and 2.0 GHz. Although the tuning has been automated, further optimization is possible. Automated tuning is demonstrated over 400 MHz of bandwidth with a minimum cancellation of 110 dB. One application for the harmonic cancellation is to create a linear radar transmitter for the remote detection of non-linear targets.

Growing community of inventors

Derwood, MD, United States of America

Kyle Alexander Gallagher