Abstract: A system for efficiently filtering interfering signals in a front end of a GPS receiver is disclosed. Such interfering signals can emanate from friendly, as well as unfriendly, sources. One embodiment includes a GPS receiver with a space-time adaptive processing (STAP) filter. At least a portion of the interfering signals are removed by applying weights to the inputs. One embodiment adaptively calculates and applies the weights by Fourier Transform convolution and Fourier Transform correlation. The Fourier Transform can be computed via a Fast Fourier Transform (FFT). This approach advantageously reduces computational complexity to practical levels. Another embodiment utilizes redundancy in the covariance matrix to further reduce computational complexity. In another embodiment, an improved FFT and an improved Inverse FFT further reduce computational complexity and improve speed.

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: An amplifying device comprises an electron gun emitting an electron beam, a collector spaced from the electron gun, the collector oriented to collect electrons of the electron beam emitted from the electron gun, and an interaction structure interposed between the electron gun and the collector. The interaction structure defines an electromagnetic path along which an applied electromagnetic signal interacts with the electron beam. The interaction structure further comprises a plurality of polepieces and a plurality of magnets, the polepieces each having an aligned opening to collectively provide an electron beam tunnel having an axis extending between the electron gun and the collector to define an electron beam path for the electron beam. The polepieces provide a magnetic flux path to the electron beam tunnel from the magnets. More particularly, the interaction structure further includes plural cavities defined therein interconnected to provide a coupled cavity circuit.

Abstract: In many systems now in use for sending digital data from a controlled station (e.g., a transmitting station), generally indicated at 10 in FIG. 1, to a controlling station (e.g., a receiving station) generally indicated at 12, a plurality of hopping frequencies are provided. In such systems, a first packet is transmitted from the controlled station 10 to the controlling station 12 at a first one of the hopping frequencies in the plurality. The data in a second one of the packets is then transmitted from the controlled station 10 to the controlling station 12 at a second one of the hopping frequencies. The data in a third one of the packets is subsequently transmitted from the controlled station 10 to the controlling station 12 at a third one of the hopping frequencies.

Abstract: A radial power divider-combiner is disclosed. The divider-combiner includes a divider and a combiner. An input signal is provided to a transmission antenna that radiates the input signal inside the divider. Within the divider, the input signal is divided into a plurality of individual signals. The individual signals are received by receiving antennas and provided to respective amplifiers. The amplifiers amplify the respective individual signals by a desired amplification factor. The amplified individual signals are provided to a plurality of transmitting antennas within the combiner. Inside the combiner, the amplified individual signals are combined to form an output signal that is received by a receiving antenna in the combiner.

Abstract: Sensing characteristics of an object includes transmitting a stepped-frequency radar through an object and detecting, with multiple receiving structures, deflected portions of the radar signal. The detected portions are processed to generate processed data including information associated with amplitudes and phases of the deflected portions, and with the locations of the receiving structures at which the deflected portions were detected. The processed data is analyzed to determine information corresponding to dielectric properties particular positions within the object.

Abstract: A system for baseband amplitude limiting is provided. The system includes a CORDIC vector mode rotator device having an angle accumulator in addition to a gain device and limiter. The system also includes a second CORDIC rotator operating in rotation mode, and is coupled to the limiter.

Abstract: A security system for use in connection with cargo containers and other enclosed spaces. The system monitors vibrations associated with a container and detects signals representative events indicating that an unauthorized access has been made to the container. The system may be programmed with a library of event signatures, allowing different types of events to be detected. The system may be provided with a library of signatures representing a heart beating with a beat pattern and the system may be used to detect a human or other animal within the container. Alternatively, the system may be provided with a library of signatures representing piercing the container. The system may be used to monitor containers in transit. Indications of events may be stored while the container is in transit and then communicated at a security check point.

Abstract: An multi-mode target detection system includes a ground penetrating metal detector and a ground penetrating radar detector permitting operation of the system in a variety of target detection modes. The system includes a control section having a selection device for selecting at least two operating modes from the group consisting of a buried land mine detection mode, a through wall detection mode, a perimeter warning mode, a buried cache detection mode and an in-wall cache detection mode.

Abstract: A method or apparatus for analyzing an object includes an X-ray prescanner that performs a prescan of the object to determine prescan information about the object. Then, a CT scanner performs a CT scan on at least one plane of the object based on the prescan information to determine CT information. In one embodiment, if the CT scan of the object includes or is in the vicinity of metal, then metal artifact correction of a reconstructed image from the CT scan is performed based on the prescan information. In another embodiment, a processor analyzes the CT information and the prescan information to determine whether to update the prescan information based on the CT information.

Abstract: The application discloses a system and methods for remote access and analysis of data collected about items under inspection. The system includes one or more data collection stations, each of which may include an X-ray scanner that scans the items under inspection to obtain data about the items. The data is transmitted to one or more remote stations, where the data is remotely analyzed to determine whether the item contains a potential threat, such as, for example, explosives or other contraband. Data may be aggregated so that correlations between data collected for different items may be used to more accurately detect threats.

Abstract: A PN code hopping method for mitigating cross-correlation interference is provided. The method includes the steps of providing a memory device and storing a plurality of PN codes, where each PN code is associated with a useful life cycle. The PN codes are pseudo-randomly accessed and used to spread a modulated signal for their respective useful life cycle before another PN code is pseudo-randomly retrieved.

Abstract: A method and system includes at least one interconnect hub, connecting the at least one interconnect hub to a plurality of audio connection devices to form a network of audio connection devices with the interconnect hub at the center of the ring. The audio connection devices are connected to each other through the at least one interconnect hub, and data is synchronously transmitted between at least two of the audio connection devices through the at least one interconnect hub.

Abstract: A portable target locator for use by a ground observer to accurately determine the location of a target and transmit location information and firing instructions to an unmanned vehicle so the unmanned vehicle can locate the target and perform an operation based on the firing instructions. The apparatus comprises optics for permitting a user to see a magnified view of the target; a location determining component for determining a location of the apparatus; rangefinder for determining a range from the apparatus to the target; an Azimuth sensor for determining an Azimuth from the apparatus to the target; a processor for determining the location of the target based on the location of the apparatus, the range to the target, and the Azimuth from the apparatus to the targets, a transmitter for transmitting the location information and the firing instructions to the unmanned vehicle, and a portable handheld housing.

Abstract: A system for efficiently filtering interfering signals in a front end of a GPS receiver is disclosed. Such interfering signals can emanate from friendly, as well as unfriendly, sources. One embodiment includes a GPS receiver with a space-time adaptive processing (STAP) filter. At least a portion of the interfering signals are removed by applying weights to the inputs. One embodiment adaptively calculates and applies the weights by Fourier Transform convolution and Fourier Transform correlation. The Fourier Transform can be computed via a Fast Fourier Transform (FFT). This approach advantageously reduces computational complexity to practical levels. Another embodiment utilizes redundancy in the covariance matrix to further reduce computational complexity. In another embodiment, an improved FFT and an improved Inverse FFT further reduce computational complexity and improve speed.

Abstract: A security system comprises a computer network and a plurality of sensors each connected to the computer network at a respective network address and each generating sensing data. A managing component is connected with the network and communicates with the sensors by access thereof through the associated network address on the network, and processes sensor information received from said sensors. The managing component has a display with an interface screen showing to a user all the sensors in the security system, and an input device through which the user can enter interactive instructions to the managing component. The managing component controls communications to and from the sensors and has a rules engine storing rules therein. Each of the rules being associated with a respective device on the network, and causing the managing computer to take an action in response to output from at least one of the devices.

Abstract: A system and method for generating a navigation solution in high interference and dynamic environments using Global Positioning System (GPS) and inertial measurement unit (IMU) data is described. The system includes an Advanced Tightly Coupled (ATC) tracking processor for a multi-satellite tracking system. The ATC accepts early, late, and on-time I and Q data from the GPS signal tracker and outputs vehicle-to-satellite range and range rate residual measurements to a navigation Kalman filter. The ATC includes nonlinear discriminators which transform I and Q data into linear residual measurements corrupted by unbiased, additive, and white noise. It also includes an amplitude estimator configured to operate in rapidly changing, high power noise; a measurement noise variance estimator; and a linear residual smoothing filter for input to the navigation filter.

Abstract: A method and apparatus for inspecting items for the presence of contraband. Trays may be used to hold items as they move through an inspection station. After use, the trays may be mechanically conveyed back to an entry region of the inspection station so that the trays may be used to move other items. Mechanically conveying the trays may enable increased throughput for inspection stations. A tray return may be constructed from multiple modules positioned to the side of an inspection machine. In use at an airport or other similar facility, the tray return may face a passenger use area at an inspection station. Passengers exiting the inspection station may place trays in the tray return. Passengers entering the inspection station may remove a tray from an end of the tray return at an entrance of the inspection station.

Abstract: A system and method for transporting data are provided. A first domain includes a first plurality of filters in a first communications channel including a common portion. A second domain includes a second plurality of filters in a second communications channel including the common portion. The first and second plurality of filters employ first and second plurality of filtering criteria. A plurality of managers, each coupled to one of the first and second plurality of filters, includes a mechanism for configuring the one of the first plurality of filters and the second plurality of filters. At least one control terminal is coupled to the plurality of managers for controlling the plurality of managers.

Abstract: An arcing protection circuit for the screen and accelerator grids of an ion thruster engine includes an impedance, which in one embodiment, is fixed, and in another, is variable, coupled in series between the accelerator grid of the engine and a current return path of the grid in such a way that an increase in accelerator grid current resulting from a plasma arc occurring between the screen grid and the accelerator grid is converted by the impedance into a rapid reduction in the voltage difference between the screen and accelerator grids, thereby extinguishing the arc. The arcing protection circuit also includes a monitoring circuit coupled to the accelerator grid that senses an increase in the voltage on the accelerator grid resulting from the plasma arc, and in response thereto, causes the accelerator grid power supply to reduce the voltage on the accelerator grid.