Abstract: An embodiment disclosed herein is directed to a method of monitoring an electromagnetic shield effectiveness including transmitting a first electromagnetic field toward a first surface of an electromagnetic shield, detecting a second electromagnetic field transmitted from a second surface of the electromagnetic shield, generating a first signal corresponding to the second electromagnetic field and determining whether a defect exists at the electromagnetic shield by comparing the first signal to a predetermined threshold.

Abstract: A distribution of heavy particle stopping power is be determined. A distribution of effective atomic number of a three-dimensional space is accessed, and a distribution of an x-ray stopping power of the three-dimensional space is accessed. A conversion is applied to the distribution of the effective atomic number and the distribution of x-ray stopping power. A distribution of the heavy particle stopping power of the three-dimensional space is generated based on the conversion, the heavy particle stopping power being an indication of a depth of penetration for a heavy particle incident on the three-dimensional space.

Abstract: A method and apparatus for reducing the likelihood of an article becoming jammed in a conveyor system. The width of an article, like luggage, may be detected and the article rotated if the width is greater than a threshold value. A jammed article in the conveyance system may be detected, and repositioned by a positioner, to clear the jam. Spacing between articles in the conveyor system may also be controlled.

Abstract: A property of a treatment beam is controlled during a scanning period. A portion of a region is exposed to an imaging x-ray beam during a scanning period, the imaging x-ray beam being generated by an electron-beam scanner. X-ray radiation from the region is detected, the x-ray radiation representing an attenuation of the imaging x-ray beam caused by the portion of the region. A first image of the portion of the region is generated based on the detected x-ray radiation. A characteristic of the portion of the region is determined from the generated first image. An input derived from the characteristic is generated, the input configured to cause a source of a treatment beam to modify a property of the treatment beam. The source of the treatment beam modifies a property of the treatment beam during the scanning period by providing the input to the source of the treatment beam.

Abstract: An apparatus that includes a traveling-wave tube having an electron gun having a cathode. The apparatus also includes a first power supply for establishing a first electric potential between the cathode and an anode and for providing an operational current to the cathode to generate a beam of electrons. The apparatus also includes a slow-wave structure having a passage through which the beam of electrons passes. The apparatus also includes a second power supply for providing a voltage to a beam focusing electrode to establish an electric potential between the cathode and the beam focusing electrode. The apparatus also includes a switching module coupled to the first power supply and the second power supply, the switching module providing a current path between the cathode and the beam focusing electrode, wherein the current path is disabled when a biasing current is below a predetermined level.

Abstract: An electronically reconfigurable battery includes a number of battery modules selectively interconnected by a number of electronic switches, wherein a selectable number of battery modules may be connected either in a series configuration or in a parallel configuration, as a result of placing selected switches of said plurality of switches in open states or closed states. In a parallel configuration, the battery provides power to a primary load, such as a propulsion load for a vehicle. In a series configuration, the battery is configured to provide a high voltage and high power output to a short-term and/or pulsed load, such as an additional load provided on the vehicle.

Abstract: Systems and methods that may be employed to communicate location information between two or more aerial vehicles or other types of vehicles or other entities, and/or that may be used to facilitate coordinated operations of two or more such entities. In one example, an aerial vehicle may be kept aware of one or more location (e.g., longitude, latitude, etc.) and/or flight characteristics (e.g., altitude, directional heading, airspeed, attitude, etc.) of one or more other adjacent aerial vehicles, and each such aerial vehicle may use that location information to adjust its flight path to maintain a safe sphere of empty airspace around itself.

Abstract: An inspection system that can detect contraband items concealed on, in or beneath an individual's clothing. The system employs millimeter wave radiation to detect contraband items. The system is described in connection with a check point security system that includes temperature controlled walls to enhance imaging of contraband items. Also, a millimeter wave camera is used in conjunction with a visible light camera that forms images. To address privacy concerns of displaying images of people made with millimeter wave cameras that effectively “see through” clothes, the millimeter wave images are not displayed directly. Rather, computer processing produces indications of suspicious items from the underlying raw millimeter wave images. The indications of suspicious items are overlaid on the image formed by the visible light camera.

Abstract: A signal of interest (SOI) may be selected from among a plurality of cochannel signals based on one or more internal or external structural feature/s of the SOI, e.g., automatically selected based on any one or more internal or external structural features of the SOI that is known a priori. Examples of such internal structural features include, but are not limited to, number, frequency and/or absolute or relative signal strength (signal to noise ratio) of one or more transmitted signal components (e.g., pilot tones, squelch tones, etc.) present in the SOI; absence of a signal component at a given frequency in the SOI (i.e., present as a “dead spot” at a given frequency within the SOI); signal strength versus frequency profile of the SOI, signal strength versus time domain profile of the SOI, transient characteristics, time versus frequency profile, etc.

Abstract: A volumetric image of a space is acquired from an imaging system. The space includes an object of interest and another object, and the volumetric image includes data representing the object of interest and the other object. A two-dimensional radiograph of the space is acquired from the imaging system. The two-dimensional radiograph of the space includes data representing the object of interest and the other object. The two-dimensional radiograph and the volumetric image are compared at the imaging system. A two-dimensional image is generated based on the comparison. The generated two-dimensional image includes the object of interest and excludes the other object.

Abstract: A trace sampling detection system includes a gathering device configured to gather particles through a handle-bar, a gate and an air-stream gatherer. The handle-bar includes collection holes positioned to be adjacent to a user's hand when the user grips the handle-bar, and is configured to dislodge and capture particles from the user's hand when the user grips and moves the handle-bar. The gate includes a series of collection holes, is positioned to be adjacent to the user's clothing when the user traverses the gate, and is configured to dislodge and capture particles from the user's clothing in response to pressure applied from the user. The air-stream gatherer includes an outward vent and an in-drawing vent, and is positioned to enable objects, such as the user's feet, to be placed between the outward and in-drawing vents. The air stream is configured to dislodge and capture particles from objects, such as the user's feet, that block the air-stream between the vents.

Abstract: An inspection system that forms material sensitive X-ray images of items under inspection. The images are decomposed into basis function images using basis functions representative of materials of interest. The decomposed images may be processed separately to detect concentrations of a material of interest corresponding to one or more of the basis functions. When operated in this mode, the inspection system may be used in applications such as material sorting or security screening. At least one basis function is selected to distinguish a material of interest from other materials likely contained with the item, allowing one of the basis function images to be analyzed to obtain information about a specific material of interest. The images may be automatically analyzed or may be superimposed for display with different visual characteristics assigned to the components associated with each basis function for analysis by a human operator.

Abstract: Sample vectors of a signal received simultaneously by an array of antennas are processed to estimate a weight for each sample vector that maximizes the energy of the individual sample vector that resulted from propagation of the signal from a known source and/or minimizes the energy of the sample vector that resulted from interference with propagation of the signal from the known source. Each sample vector is combined with the weight that is estimated for the respective sample vector to provide a plurality of weighted sample vectors. The plurality of weighted sample vectors are summed to provide a resultant weighted sample vector for the received signal. The weight for each sample vector is estimated by processing the sample vector in accordance with the expression: min w _ , c _ ? ? X * ? Y ? ? w _ - ( C 0 ? c _ 0 + C ? ? c _ ) ? p ? where c0=1 and 0<p??.

Abstract: A compact integrated waveguide load has a load section disposed within an interior region of the waveguide proximate to a closed end of the waveguide. The load section has a tubiform shape, with an exterior surface congruent with an interior surface of the waveguide and an interior surface defining a circumferential step within the waveguide. A method of making a compact integrated waveguide load includes providing a waveguide and placing electromagnetic wave absorbing materially circumferentially around the interior surface to create an inward step.

Abstract: X-ray radiation is generated at a target that emits x-ray radiation in response to being struck by accelerated electrons, the electrons being emitted by a cathode that emits electrons in response to being illuminated by electromagnetic radiation from a source, and the x-ray radiation is moved by orienting a surface that directs the electromagnetic radiation from the source toward the cathode.

Abstract: A property of a treatment beam is controlled during a scanning period. A portion of a region is exposed to an imaging x-ray beam during a scanning period, the imaging x-ray beam being generated by an electron-beam scanner. X-ray radiation from the region is detected, the x-ray radiation representing an attenuation of the imaging x-ray beam caused by the portion of the region. A first image of the portion of the region is generated based on the detected x-ray radiation. A characteristic of the portion of the region is determined from the generated first image. An input derived from the characteristic is generated, the input configured to cause a source of a treatment beam to modify a property of the treatment beam. The source of the treatment beam modifies a property of the treatment beam during the scanning period by providing the input to the source of the treatment beam.

Abstract: A system and method is disclosed for protecting a receiver configured to receive a plurality of contemporaneous spread spectrum signal bursts from a denial of service attack. The method includes the operation of detecting a burst transmission that includes a random burst number. The burst transmission can be analyzed to determine a denial of service statistic based on the random burst number. The burst transmission is processed when the denial of service statistic is within a predetermined threshold.

Abstract: A receiver, which is adapted for demodulating signal carriers at variable frequencies to provide received signals at a plurality of different received frequencies, is calibrated to compensate for a frequency-dependent imbalance in the amplitude and/or the quadrature phase of analog in-phase (I) and quadrature (Q) received-signal components that have passed through receiver circuit paths that may cause such imbalance. I-channel and Q-channel Rx-correction coefficients for each of a plurality of different calibration frequencies are estimated and stored in a lookup table.

Abstract: A high voltage propellant isolator includes at least two different types of isolator rings or segments, in alternating lateral arrangement, that direct the flow of propellant, such as xenon gas, in a tortuous path through the isolator.

Abstract: In one aspect, an x-ray scanning device is provided. The x-ray scanning device comprises a target adapted to convert electron-beam (e-beam) energy into x-ray energy, a detector array positioned to detect at least some x-rays emitted from the target, and a conveyer mechanism adapted to convey items to be inspected through an inspection region formed by the target and the detector array, wherein the target and the detector array are rotated out of alignment with each other such that x-rays emitted from the target impinge on diametrically positioned detectors of the detector array without passing through near-side detectors of the detector array.