US Government As Represented by the Secretary of the Army

Other

Gard, Inc.

Richard N Johnson

Andree N Filipov

Marvin J Schneider

Wieslaw L Lichodziejewski

Irvin R Kraska

Thomas A Mathieson

Christopher N Winslow

David Leo Gamache

Leon Ash

An improved chaff in which a plurality of metallic or metallic coated elets are joined as chain links that, when deployed, produce microarcs when the link elements make and break contact with each other in an electromagnet field such as that created by a high power radar transmitter. These microarcs will then in turn create current spikes that will reflect a radar signal that has a wider bandwidth than conventional chaff, so as to make it more difficult to distinguish the chain link chaff from a fast moving target such as an aircraft.

Microarc chaff

An improved power wheelchair is provided that provides exceptional maneuverability, stability and directional tracking characteristics. The wheelchair includes a torsional frame and a rigid stability frame. Two main wheels and a pivoting drive wheel are coupled to the torsional frame. At least two freely rotating casters are coupled to the stability frame. The torsional frame and stability frame interact to provide automatic compensation for directional tracking errors caused by shifts in the mass center of an occupant. The wheelchair can be equipped with either manual or power steering. A unique three-point battery mounting assembly also permits easy replacement of batteries.

Power wheelchair with torsional stability system

A method and apparatus for converting thermal energy into mechanical energy by parametric pumping of rotary inertia. In a preferred embodiment, a modified Tesla turbine rotor is positioned within a rotary boiler along its axis of rotation. An external heat source, such as solar radiation, is directed onto the outer casing of the boiler to convert the liquid to steam. As the steam spirals inwardly toward the discs of the rotor, the moment of inertia of the mass of steam is reduced to thereby substantially increase its kinetic energy. The laminar flow of steam between the discs of the rotor transfers the increased kinetic energy to the rotor which can be coupled out through an output shaft to perform mechanical work. A portion of the mechanical output can be fed back to maintain rotation of the boiler.

Parametric energy converter

A method and apparatus for forming a set of simultaneous multiple antenna beams. The digital technique utilizes a Fermat Number Transform (FNT) processor which takes the transform of number sequences consisting of the output signals from the elements of a preferably circular, equiangularly spaced antenna array, then forms the complex linear vector product of the transformed signals and a stored beam-forming function, and finally processes the complex linear vector product through an inverse FNT network to generate a set of simultaneous multiple antenna beams. The advantages of utilizing the FNT include reduced hardware requirements, greater processing speed due to a reduction in multiplications required to be performed, and sharper output beams due to the absence in the FNT of round-off errors.

Digital beam former

An analog-to-digital converter is disclosed providing high speed operation or high resolution analog signal data. The converter utilizes the repetitive nature of the data by converting a portion of the signal corresponding to the changing component of the data. A smaller number of bits of information is thus converted from analog-to-digital form than is needed to represent the data. In addition to savings in hardware, a significant saving in conversion time is provided. The cancellation of static components of a radar signal moreover provides, within the system, a clutter-free signal.

Radar analog to digital converter

A digital computing method and apparatus for complex numbers which, more particularly, comprises a technique and hardware for forming the complex linear vector product of two transformed sequences. The invention is designed for use in a computer system wherein all arithmetic is performed modulo a number of the form 2.sup.b +1 and, in essence, consists of replacing complex numbers of the form A+jB by numbers of the form A.+-.2.sup.b/2 B, after which products, sums and differences are computed to yield the desired result.

Method and apparatus for forming convolutions of two complex number

A method and apparatus for modifying data which is stored in a medium of hival quality. The original data is left unmodified, and a modification document is prepared which has addition and deletion data thereon. The original and modified data is combined in a given way to generate a correctly modified composite.

Data base update scheme

A system, preferably a pulse echo reflection system, for residual tire life prediction by ultrasound includes: a transmitter transducer; means to provide pulses of electrical energy to the transmitter transducer, that converts the electrical pulses into pulses of ultrasonic vibrations and transmits them into an area of the plycontaining portion of the carcass of a tire, having a number of plies in the carcass, to be tested; clock means to control the frequency of the electrical pulses; a receiver transducer mounted relative to the transmitter transducer to receive ultrasonic energy reflected by the tire; amplifier means connected to the receiver transducer to receive reflected ultrasonic energy from different levels within that portion of the carcass of the tire, including reflected ultrasonic energy from plies of the carcass of the tire; processing means having an input connected to the amplifier; and gate means responsive to the clock means to provide, after a delay following each electrical pulse, a time-gated signal from the output of the amplifier means to the input of the processing means that, for each ultrasonic pulse to the tire, includes only the amplified signals corresponding to the reflected ultrasonic energy from a level adjacent but outwardly of the outermost ply of that portion of the carcass of the tire to a level inwardly of at least the outermost ply of that portion of the carcass. The processing means is constructed to provide a signal indicative of ply degradation or separation based on the time-gated signal.

Growing community of inventors

Adelphi, MD, United States of America

Richard N Johnson