US Government As Represented by the Secretary of the Army

Geoffrey H Goldman

Kenneth Irving Ranney

Fa Dai

Marc Allan Ressler

William O Coburn

Roberto Innocenti

Tung-Duong Tran-Luu

Jerry Lee Silvious

Thomas J Pizzillo

An RF system comprising of outputs to an electronically scanning antenna for radiating electromagnetic energy; at least one waveform generator; two multiphase phase-locked loops integrated with the waveform generator, the phase locked loops operating to provide multiple shifted phases to a waveform. Optionally, the two multiphase phase-locked loops may each be divided down by a bank of frequency dividers to further increase the number of phase shifts. The phases generated from each multiphase phase-locked loops are selected with multiplexers then mixed together. These upper or lower sidebands are then mixed with the up converted waveform which results in a phase shift for the waveform associated with each antenna element.

RF system with integrated phase shifters using dual multi-phase phase-locked loops

An improved method and system for removing time-varying Doppler shifts and the effects of turbulence from data comprising at least one processor operating to estimate the average instantaneous frequency; reduce or remove noise from the state space variables estimates describing the frequency of the target; compensate for the motion of the target to obtain motion compensated data and increase the coherency of the data, and reduce or remove the noise from the state space variables describing the frequency of the target using a filter or smoother. Alternately, the method and system may comprise at least one processor operating to estimate the average instantaneous frequency of the first harmonic of a moving target; the average instantaneous frequency being inputted into an error reduction subroutine; using state space estimates of the frequency, calculating a time warping to remove the effect of the Doppler shift; and focusing the data using a modified PGA.

Method and system for motion compensated target detection using acoustical focusing

Embodiments of the present invention generally relate to motion compensation, and in particular to an autofocus-based compensation (ABC) systems and methods for a ground moving target indication platform. According to one embodiment, a method for autofocus based compensation of range data acquired from an object in motion is provided. The method may include: receiving range data; steering at least one receive beam of the range data in a desired direction; transforming the range data into the range domain; determining the width of a main clutter lobe; excluding data that is not part of the main lobe clutter response; transforming the main-lobe clutter response into the range domain; calculating a phase correction term; and applying the phase correction to the original range data.

Autofocus-based compensation (ABC) system and method for a hovering ground moving target indication (GMTI) sensor

A radar system, apparatus, and method includes at least one radar transmitter for transmitting an electromagnetic waveform; a receiving antenna comprising a plurality of receiving antenna elements and delay lines, each of the plurality of receiving antenna elements receiving the return signal operatively associated with a predetermined delay line; each delay line having a delay length which produces a different phase delay in the return signal; the different phase delays producing substantially different antenna patterns for the received signal at a given frequency; at least one processor operatively connected to receive data from the plurality of delay lines; the at least one processor operating to analyze the substantially different beam patterns for a given frequency; whereby the processing of the data produces results indicating the presence and location of a target.

Radar system and antenna with delay lines and method thereof

A method and system for processing radar data from a movable platform comprising passing a radar signal through a low noise amplifier; down converting the signal to a lower frequency; filtering out harmonics; sampling using A/D converter at or above Nyquist frequency; determining a scene center; performing a two stage averaging scheme of the received signals with a variable window function based upon the velocity, acceleration of the platform and scene center; coherently averaging N pulses to create an average pulse; performing an inverse Fourier transform; compensating to the scene center by multiplying by a complex exponential based upon GPS and inertial navigational system; summing the average pulses using a low pass filter; repeating the determination of an average pulse for a time period that is less than the Nyquist sample time interval to generate second average pulses; and performing a 2D inverse Fourier transform to obtain SAR image.

Computationally efficent radar processing method and sytem for SAR and GMTI on a slow moving platform

A system for the measurement of an angle of roll of a projectile is disclosed. The projectile has a casing with a rear end, a front end, and a side wall extending therebetween. The system includes a radar configured to transmit a polarized electromagnetic signal toward the projectile and a groove disposed on the side wall of the casing. The groove has a width, a depth, and a length, the width extending along a longitudinal axis of the projectile, the depth extending inwardly from an outer surface of the casing toward the longitudinal axis, and the length extending along the outside of the casing. The radar is further configured to receive a return signal from the projectile, wherein the return signal from the groove is modulated as a function of the angle of roll of the projectile. Amplitude or phase modulation of the return signal from the groove can be used to uniquely determine the roll angle of the projectile.

System and method for the measurement of the unambiguous roll angle of a projectile

Systems, methods, and devices for detecting land mines and unexploded ordnance are disclosed. A first embodiment may be construed as a method that includes: inserting an antenna into the ground; transmitting an electromagnetic signal into the ground via the antenna; receiving a response via the antenna; and processing the response to generate an image which can be examined to determine whether a mine exists within proximity of the antenna.

Systems and methods for mine detection

One embodiment of the system is implemented as an aircraft comprising a rotor. For example, the aircraft may be a helicopter. This embodiment also comprises an acoustic source, wherein this acoustic source comprises an acoustic signature of the aircraft. This particular embodiment also comprises an acoustic collection device affixed to the aircraft. The acoustic collection device preferably comprises an array of microphones. Finally, this embodiment also has a data processing device, such as a computer, for collecting the data detected by the microphones and processing this data. In operation, the aircraft is flown for a distance along a path while the aircraft emits acoustic energy. Then, the microphones detect the acoustic energy that is reflected off the terrain. Optionally, the detected energy may be stored as data and processed, so that noise may be reduced and a terrain image may be formed.

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Ellicott City, MD, United States of America

Geoffrey H Goldman