Abstract: A frequency domain kernel phase processor comprises an input buffer to st Fourier coefficients input from a Fourier transform of a communications signal. A communications signal suitable for processing by the present invention typically comprises a desired signal masked by a stronger interference signal having varying power that spans a range of frequency bins encompassing the desired signal. A scheduler inputs Fourier transform coefficients from the input buffer and generates a series of magnitude squares and symmetric phase differences for each frequency bin. The magnitude squares and the symmetric phase differences are output to phase transform processors which transform the symmetric phase differences to reveal the desired signal. The transformed outputs from the phase transform processors are output to an output buffer to be formatted and displayed.

Abstract: A method of encoding a digital image using adaptive partitioning in an iterated transformation image compression system is provided. A set of ranges R is initialized to include at least two uncovered ranges. A set of domains D is initialized to include only one member which is the entire image area.For each uncovered range in the set R: A transformation is generated for each domain in the set of domains. Each domain is transformed into corresponding transformed images to map onto each uncovered range in the set R. Each domain's transformation is optimized and is indicative of a domain's corresponding optimized transformation image for an associated uncovered range. Each optimized transformation image is compared with the associated uncovered range to provide error data as a function of the difference therebetween. The associated uncovered range is redefined as a covered range when the error data for the associated uncovered range is within predefined limits.

Abstract: A system for generating three dimensional images includes a data processor which generates a first data stream representing coordinates along a first axis, a second data stream representing coordinates along a second axis, and a third data stream representing intensities of optical beams. A demultiplexer transforms the first, second, and third data streams into multiple control signals each comprised of elements of the first, second and third data streams. The system further includes an optical energy source for generating an optical signal, and an optical beam steering system which divides the optical signal into multiple optical beams which are individually deflected and intensity modulated under the control of one of the control signals. The optical beams then are recombined and steered to reflect off the reflecting surface of a reflective structure, resulting in the presentation of a 3D image.

Abstract: A system for measuring toxicity levels of a solution includes a water proof sample container transparent to visible light which holds an aqueous test solution containing bioluminescent organisms. A light tight chamber has a cavity which holds the sample container and includes a light port. A stress generating system positioned in the sample container generates pressure pulses which stimulate the organisms to generate light emissions. A light detector system mounted to the light tight chamber in a light tight manner detects light emissions generated in the sample container which propagate through the light port and are received by the light detector system. The light detector system generates an electric pulse in response to detecting each detected light emission. A controller enables the stress generating system and the light detector system, and then counts the electric pulses within a predetermined period of time.

Abstract: An electromagnetic energy detector system down converts electromagnetic egy from a relatively high energy beyond the detectable range of an electromagnetic energy detector to a lower energy level within the detectable range of the electromagnetic energy detector. The detector includes a transparent substrate, a porous silicon structure formed on the substrate for down converting electromagnetic energy characterized by a first wavelength W1 to electromagnetic energy characterized by a second wavelength W2, where W2>W1; and an electromagnetic energy detector for detecting the down converted electromagnetic energy. The detector is useful in applications where the electromagnetic energy detector would ordinarily be incapable of detecting the higher level electromagnetic energy directly without going through the down conversion process effectuated by the porous silicon structure.

Abstract: An acoustic transponder method and apparatus provides a high degree of frency and target strength selectivity by utilizing two or more concentrically disposed, hollow spheres each containing acoustically refractive fluids. The invention provides the possibility of using spheres of a variety of diameters and as well a number of different refractive fluids, enabling the production of an acoustic transponder having a wide variety of selective frequency responses as well as effective target diameters.

Abstract: An optical probe for illuminating a location outside or inside a medical ient with a range of optical wavelengths appropriate to both diagnostic and surgical procedures comprises a polarization-preserving optical waveguide to conduct a polarized light beam to a polarizing beamsplitter, an optical detector to detect light deflected by the beamsplitter, a quarter-wave plate to couple the light between a non-refractive focusing element and a target, and a probe enclosure.

Abstract: An isolation circulator network includes three circulators and a 180 degree ybrid coupler for isolating an RF transmitter from a nearby RF receiver. The isolation circulator network comprises: a first circulator for transforming a first RF signal, RF.sub.1, into a second RF signal, RF.sub.2 and a third RF signal, RF.sub.3 ; a second circulator for throughputting the third RF signal; a third circulator for transforming the second RF signal into a fourth RF signal, RF.sub.4, and a fifth RF signal, RF.sub.5, and for throughputting a sixth RF signal, RF.sub.6 ; and a 180-degree hybrid coupler which provides a seventh RF signal, RF.sub.7 in response to receiving the third, fifth, and sixth RF signals, where RF.sub.7 =(RF.sub.5 -RF.sub.3 +RF.sub.6).

Abstract: The present invention provides a transformer which uses bi-directional syronous rectification to transform the voltage of an input signal from one voltage level to another. The invention provides a transformer which requires less core volume, and hence mass, than conventional transformers, and includes a rectifier for transforming a first time varying input signal, such as a sinusoid or saw tooth signal, into a full-wave rectified voltage signal. A synchronous switch control generates first and second control signals in response to sampling the first time varying voltage signal. A floating drive buffer generates third control signals in response to receiving the second control signals. An AC switching stage transforms the full-wave rectified voltage signal into a first and second series of voltage pulses in response to receiving the first control signals. Each of the first and second series of voltage pulses has a pulse period, T, and a pulse width, .omega..

Abstract: An optically based position location system, comprises multiple reflectors ositioned at known locations in an environment; a vehicle for traveling along a path in the environment; a first sensor for generating and detecting a collimated and polarized first light signal reflected from one of the reflectors, and for generating a first output signal in response to detecting the first light signal; a second sensor for generating and detecting a collimated and polarized second light signal reflected from the reflector reflecting the first light signal, and for generating a second output signal in response to detecting the second light signal; and a data processor which uses the first and second output signals for determining the distance between a reference coordinate on the vehicle and the reflector.

Abstract: Transmitted signals are used to remotely assess sea surface roughness and nce wind speed at a water surface. A signal is transmitted from a signal source as it moves either through air or space. A land- or sea-based antenna receives the signal directly from the signal source and indirectly from the signal source by way of reflection of the signal from the surface being examined. The sum of the directly and indirectly received signals form an interference pattern as the signal source is moved. The interference pattern has peak-to-null signal values that are characteristic of the surface conditions being analyzed. Reference interference patterns are then generated for known surface conditions, each of the reference patterns exhibiting "known" characteristic peak-to-null signal values. The peak-to-null signal values of the reference interference patterns are then compared to the peak-to-null signal values generated from the surface being examined.

Abstract: A secure communication system comprising:a first cyclical pseudo-random noise generator comprising determinable vable starting point means and an output;transmitting means for transmitting said pseudo-random noise generator output;receiving means for receiving said transmitting means transmissions, said receiving means having an output;recycling storage means for storing said receiving means output;a second cyclical pseudo-random noise generator identical to said first pseudo-random noise generator having an output and a reset input, said receiving means output connected to said reset input;a correlator having a first input connected to said storage means and a second input connected to said second pseudo-random noise generator output and an output from said correlator; andtiming means connected to said receiving means output and said correlator output for measuring time elapsed between any output of said receiver and said correlator.

Abstract: A system for determining the time between the receipt of two different sils, includes a voltage ramp generator which generates a time dependent voltage signal upon receipt of a timing pulse at a time T.sub.1, and provides the instantaneous value of the voltage signal when the voltage ramp generator receives an input signal having a predetermined threshold value at time T.sub.2. A data processor coupled to receive the voltage signal, generates the timing pulse, and determines a time difference .DELTA.T from the voltage signal, where .DELTA.T=T.sub.2 -T.sub.1.

Abstract: The invention exploits the phenomenon of stochastic resonance in a nonlinear dynamic system to enhance the system's response to a weak periodic signal locally corrupted by background noise. The invention is designed to enhance the signal-to-noise ratio (SNR) in the system's output power spectrum at the periodic signal's frequency. This technique utilizes an array of nonlinear dynamic elements whose individual outputs are specifically coupled to other array elements. The coupling is found to substantially enhance the output SNR over what would be expected from a signal processor based upon a single such element. This principle has the potential to substantially enhance the performance of arrays of nonlinear devices; in fact, the nonlinear array can be expected to yield an output SNR that is very close to that obtainable by an array of ideal linear devices, so that the coupling actually "linearizes" the nonlinear system.

Abstract: A laser diode power combiner comprises a dye laser operably coupled to an array of laser diodes for combining optical power from the laser diodes into a single, coherent laser beam.

Abstract: The objective evaluation of a subject's interest in specific information, such as education and training materials, for example, is made possible by using patterns of physiological activity generated in the brain. Samples of individual brain activity are obtained to assess whether an individual is paying attention and showing interest in certain materials. Effectiveness in presenting such materials would be improved when direct brain recording activity shows increased interest in the presented material.

Abstract: A series of sigma-delta modulators are connected in a cascaded architecture. Each sigma-delta modulator has a noise transfer function that defines a unique set of quantization noise transmission zeros. A circuit is coupled to the cascaded architecture and has a signal transfer function that is an approximation of the noise transfer function of a first sigma-delta modulator in the series of sigma-delta modulators.

Abstract: A method and apparatus for enhancing computer-user selection of computer-displayed objects reduces required cursor travel distance to an object by increasing the effective object selection area without enlarging the displayed size of either the object symbology or cursor. This is done through the constant computation of a "selectable" cursor target, which is the object closest to the current cursor position on a computer-display. The distance to all display symbols is computed in real-time as a cursor is moved. The system identifies the "selectable" object by providing a visual indication to the computer-user of the closest object to the cursor before a computer-user selection action is made. A computer-user selection confirmation action, such as the depressing of a mouse switch, erases the "selectable" object identifier and displays a visual indication that the object is a "selected" object. Object selection speed and accuracy is improved by the application of the invention.

Abstract: A digital mixing to baseband decimation filter includes a mixer section and a low-pass filter section. The mixer section generates in-phase and quadrature signal components at baseband from low-resolution, high-rate digital data lying within a signal passband offset from baseband. The low-pass filter section transforms an incoming data stream to high-resolution, low-rate digital data. The mixer section can precede or follow the filter section.

Abstract: A soil sample core system includes an outer cylinder having first and sec ends; a sample tube for sliding within the outer cylinder; a tip sleeve mounted to the first end of the outer cylinder; a push pipe which may be mounted to the second end of the outer cylinder to prevent the sample tube from sliding out of the second end; a tapered tip which may be selectively extended out of the tip sleeve and which may be selectively retracted into the push pipe; an end cap having a threaded bore which may be mounted to the second end of the outer cylinder in place of the push pipe; a threaded shaft threaded in the threaded bore; a piston rotatively mounted to one end of the threaded shaft for sliding within the outer cylinder; and a torque transmitting element mounted to the other end of the threaded shaft for transferring torque to thread the shaft through the threaded aperture.