Gregory J. Mazzaro - Charleston SC, US Bart H. Knapp - Charleston SC, US Kyle A. Gallagher - Silver Spring MD, US Kelly D. Sherbondy - Burke VA, US
International Classification:
G01S 13/88
Abstract:
Apparatuses and methods for studying and recording acoustic/electromagnetic responses of devices that contain electrical or electronic circuits help to improve the effectiveness of detecting and characterizing electronics used with an acoustic radar. The apparatuses and methods generate, measure, and record the interactions of electromagnetic (EM) and acoustic waves at or inside those devices that are to be detected using acoustic radar.
Asynchronous, Coherent, Radar Transmitter-Receiver System
- Adelphi MD, US Kyle A. Gallagher - Silver Spring MD, US Daniel T. Galanos - Silver Spring MD, US Abigail S. Hedden - Vienna VA, US Roger P. Cutitta - Westminster MD, US
International Classification:
G01S 7/288 G01S 7/292 G01S 13/00
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 (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.
Method And System For Optimizing Transceiver Spectrum Sharing
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 Apparatus For Providing A Passive Transmitter Based Synthetic Aperture Radar
- Adelphi MD, US Gregory James Mazzaro - Charleston SC, US Kyle Alexander Gallagher - Silver Spring MD, US Stephen Freeman - Ellicott City MD, US
Assignee:
U.S. Army Research Laboratory ATTN: RDRL-LOC-I - Adelphi MD
International Classification:
G01S 3/04
Abstract:
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 Detecting Objects Using A Combination Of Radio And Acoustic Signals
- Adelphi MD, US Kyle A. Gallagher - Silver Spring MD, US Kelly D. Sherbondy - Burke VA, US
International Classification:
G01S 15/02 G01S 13/86 G01R 23/165 G01S 13/04
Abstract:
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.
Methods And Systems For Locating Targets Using Non Linear Radar With A Matched Filter Which Uses Exponential Value Of The Transmit Signal
- Adelphi MD, US Kyle A. Gallagher - Derwood MD, US Kenneth I. Ranney - Rockville MD, US Anthony F. Martone - Ellicott City MD, US
International Classification:
G01S 7/292 G01S 7/41
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.
Multitone Radar With Range Determination And Method Of Use
- Adelphi MD, US Kenneth I. Ranney - Rockville MD, US Kyle A. Gallagher - Derwood MD, US Anthony F. Martone - Ellicott City MD, US
Assignee:
U.S. Army Research Laboratory ATTN: RDRL-LOC-I - Adelphi MD
International Classification:
G01S 13/10 G01S 7/28
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. 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.
Automated Cancellation Of Harmonics Using Feed Forward Filter Reflection For Radar Transmitter Linearization
- Adelphi MD, US Kyle A. Gallagher - Derwood MD, US
International Classification:
G01S 7/40
Abstract:
A novel methodology for automatically linearizing a harmonic radar transmitter—termed Feed-Forward Filter Reflection (FFFR)—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.