Raytheon Company

Vawd Applied Science and Technology Corporation

Vinh N Adams

Wesley Howard Dwelly

Michael R Beylor

Robert W Adams

Harry A Schmitt

Dennis C Braunreiter

Wesley H Dwelly

Robert J Adams

A biometric radar system and method for identifying a person's positional state are generally described herein. The biometric radar may phase adjust a sequence of radar return signals received through two or more receive antennas to remove at least some phase noise due to the stationary objects. The biometric radar may also segment the phase adjusted radar return signals into a plurality of multi-resolutional Doppler components. Each multi-resolutional Doppler component may be associated with one of a plurality of biometric features. The biometric radar system may also combine and weight the segmented radar returns for each biometric feature to generate weighted classifications for a feature extraction process.

Biometric radar system and method for identifying persons and positional states of persons

Techniques to image life forms through obstructions and at long standoff ranges employ a radar system that simultaneously transmits a plurality of RF pulse trains having different transmission frequencies and receives returns of the RF pulse trains reflected from a life form target. The returns are processed to generate digital radar data associated with the transmission frequency of each RF pulse train. The digital radar data is segmented and averaged to generate a Doppler spectrum response associated with the transmission frequency of each RF pulse train. Target classification is performed using the Doppler spectrum responses to extract biometric data describing the life form target.

Multi frequency spectral imaging radar system and method of target classification

A pulsed radar system uses phase noise compensation to reduce phase noise due to drift of the reference oscillator to enable detection of micro movements and particularly human motion such as walking, breathing or heartbeat. The noise level due to A/D sampling must be sufficiently low for the phase noise compensation to be effective. As this is currently beyond state-of-the-art for high bandwidth A/D converters used in traditional receiver design, the receiver is suitably reconfigured to use analog range gates and narrowband A/D sampling having sufficiently low noise level. As technology continues to improve, the phase compensation techniques may be directly applicable to the high bandwidth A/D samples in traditional receiver designs. Whether phase compensation is applied to traditional receiver designs or a receiver configured with analog range gates, the steps are essentially the same: data is processed to position a reference range bin (either an analog range gate or a particular time sample) on a stationary reference and the phase variation of that reference range bin is used to compensate the phase of target data in range bins (either an ensemble of range gates or other time samples) near the stationary reference. This effectively moves the radar system and particularly the reference oscillator to the stationary reference thereby greatly reducing oscillator drift and phase noise and decoupling the stand-off range from the level of phase noise.

Micro movement pulsed radar system and method of phase noise compensation

A versatile attenuator. The versatile attenuator includes a first mechanism for receiving an input signal. A second mechanism measures the input signal and provides a signal-level indication in response thereto. A third mechanism selectively attenuates the input signal when the signal-level indication surpasses a predetermined threshold and provides an attenuated signal in response thereto. In a more specific embodiment, the third mechanism further provides attenuation information. An additional mechanism then employs the attenuation information and a computer to selectively adjust an output signal of a circuit connected between the computer and the third mechanism to accommodate effects that attenuation of the input signal by the third mechanism has on the output signal.

Versatile attenuator

An adaptive waveform radar system transmits a selected waveform of a family of related waveforms and either phase shifts or bit shifts the radar return signal for correlating with the other waveforms of the family. In some embodiments, phase shifting may be performed to null an unwanted target or clutter, while bit shifting may be performed to enhance a desired target, although the scope of the invention is not limited in this respect. In some embodiments, the bits of the return signal may be either phase shifted or bit shifted to match a bit of each one of the other waveforms of the family prior to correlation.

Radar system with adaptive waveform processing and methods for adaptively controlling the shape of a radar ambiguity function

A single transmit multi-receiver modulation radar modulates radar return signals received through an associated receive-signal path with one of a plurality of differing modulation waveforms having low-cross correlation products. Each receive-signal path may be associated with a different receive direction. The differently modulated return signals from each receive-signal path may be combined and correlations may be performed on the combined and differently modulated radar return signals using the modulation waveforms to locate a target. In some embodiments, the trajectory of the target may be extrapolated and the target's source location may be determined.

Single transmit multi-receiver modulation radar, multi-modulation receiver and method

A radar system transmits an environment-sensing pulse and processing circuitry time-reverses an order of radar return samples and generates a convolution matrix from the radar return samples resulting from a transmission of the environment-sensing pulse. The processing circuitry may also generate a plurality of return energy-ranked vectors from a decomposition of the convolution matrix. The processing circuitry may select one of the return energy-ranked vectors for generation of a clutter-orthogonal transmit waveform. In some embodiments, the processing circuitry may select a clutter-orthogonal vector from the plurality of return energy-ranked vectors and may quantize the clutter-orthogonal vector for application to the phase modulator for generation of the clutter-orthogonal transmit waveform. The radar system may perform multiple correlations on sampled radar returns from the clutter orthogonal transmit waveform using a family of pseudo-orthogonal waveforms to detect a slow-moving target.

Radar system and method for reducing clutter in a high-clutter environment

In some pseudo-orthogonal waveform embodiments, a radar system transmits pseudo-orthogonal waveforms and performs multiple correlations on a combined single receiver channel signal. In some quadratic polyphase waveform embodiments, a radar system may simultaneously transmit frequency separated versions of a single quadratic polyphase waveform on a plurality of transmit antennas, combine the return signal from each antenna into a combined time-domain signal, and perform a Fourier transformation on the combined time-domain signal to locate a target. The radar system may identify a target, such as sniper's bullet, incoming projectile, rocket-propelled grenade (RPG) or a mortar shell. In some embodiments, the system may estimate the target's trajectory to intercept the target. In some embodiments, the system may estimate the target's trajectory and may further extrapolate the target's trajectory to locate the target's source, such as the sniper.

Pseudo-orthogonal waveforms radar system, quadratic polyphase waveforms radar, and methods for locating targets

A unique hardware architecture that combines short pulse, stepped frequency and centerline processing. The inventive architecture implements a radar system having a transmitter for transmitting short pulses, each pulse being stepped in frequency and a receiver receiving the pulses and providing an output signal in response thereto. In the illustrative embodiment, the transmitter includes a frequency source, an RF switch coupled to the source and a controller for controlling the RF switch. The receiver includes a signal processor implemented with a center line roughing filter. The signal processor has multiple channels each of which has a range gate and a digital filter. The digital filter includes a Fast Fourier Transform adapted to output a range Doppler matrix.

Short pulse/stepped frequency radar system

A see-through-the-wall (STTW) imaging system uses a plurality of geographically separated positioning transmitters to transmit non-interfering positioning signals. An imaging unit generates a synthetic aperture image of a target by compensating for complex movement of the imaging unit using the positioning signals. The imaging unit includes forward and aft positioning antennas to receive at least three of the positioning signals, an imaging antenna to receive radar return signals from the target, and a signal processor to compensate the return signals for position and orientation of the imaging antenna using the positioning signals. The signal processor may construct the synthetic aperture image of a target from the compensated return signals as the imaging unit is moved with respect to the target. The signal processor may determine the position and the orientation of the imaging unit by measuring a relative phase of the positioning signals.

Motion compensated synthetic aperture imaging system and methods for imaging

An oscillator to generate a low phase-noise reference signal at an oscillation frequency includes a frequency generator to generate the reference signal responsive to a control signal, and a delay element made of a high-temperature superconductor material. The delay element time-delays the reference signal and provides a low phase-noise time-delayed reference signal when cooled to a cryogenic temperature. The oscillator includes a phase detector to generate the control signal from a phase difference between the time-delayed reference signal and a phase-shifted reference signal. The delay element may comprise a coplanar waveguide having a length between 500 and 1000 meters arranged randomly on a substrate having a diameter of between five and thirteen centimeters. The delay element may provide a delay ranging from five to fifteen microseconds. The coplanar waveguide may be comprised of Yttrium-Barium-Copper Oxide disposed on either a Lanthanum-Aluminum Oxide or a Magnesium Oxide substrate.

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Tucson, AZ, United States of America

Vinh N Adams