Abstract: A system and method for volumetric display of video images extracted from arbitrary background environments comprising an arrangement for extracting a video image in real time from an arbitrary background and creating a stream of extracted image data in response thereto and a free space or volumetric display operationally adapted to display the stream.

Abstract: A system and method for combining computer generated 3D environments (virtual environments) with satellite images. In a specific application, the system enables users to see and communicate with each other as live avatars in the computer generated environment in real time.

Abstract: A receiver adapted to receive a transmitted signal and provide a replay capability in response thereto. The inventive receiver includes the medium (electronic or physical) for storing at least a portion of the received signal. In accordance with present teachings, the inventive receiver selectively outputs either a stored selection or the receive signal in response to user input (i.e. a replay signal). In the illustrative embodiment, the receiver is a satellite digital audio radio service receiver having a radio frequency tuner and audio decoder. The system controller is a microprocessor that causes the system to store each selection as it is received. In the best mode, this is facilitated by the transmission and receipt of a start of selection signal and an end of selection signal. The replay signal is provided via a user interface. Software running on a microprocessor includes code for detecting the presence of the instant replay signal.

Abstract: The invention pertains to an Internet conference call bridge management (ICCBM) system and method with which a person (customer) having access to the Internet may efficiently input the contact number of at least one party (call recipient) with whom the customer wants to speak. The ICCBM system then calls the customer, calls the party or parties, and the audio signals are bridged in a manner that optimizes the call signal to noise ratio, minimizes demands placed on computing resources, and provides controls with which the customer may monitor and control the telephonic access of the other participants through the duration of the conference call.

Abstract: An apparatus and method for determining the angular position of a rotor. The rotor is a part of a resolver used to determine the position of a shaft, or the like, in operation in a system such as a shaft in a missile gimbal. A digital signal processor is used advantageously to reduce cost. The inherently poorer performance of a data sampling approach in the presence of noise, as compared to the prior art tracking converter approach, is overcome by novel application of the digital signal processor and related circuitry.

Abstract: An aircraft based imaging system. The inventive system includes a sensor mounted in the aircraft in a known orientation, circuitry for acquiring signals generated by the sensor from a scanned area, a system for georeferencing the acquired signals; and a system for compensating for tilt in the acquired signals. In a specific embodiment the sensor is an infrared sensor and the system for georeferencing the acquired signals is a receiver adapted to receive signals from a global positioning system. In the specific embodiment, the means for compensating for tilt in the aircraft includes a gyroscope, a magnetometer and software for controlling the gyroscope to produce signals indicative of the orientation of the aircraft. The software compensates for tilt in the acquired signals and uses the GPS signals to create an accurate mosaic of the images generated by the sensor.

Abstract: A fin lock device (12) for a missile. The device (12) provides a mechanism for locking a missile fin (14) by grasping an edge of the fin (14) and a mechanism (32, 42) for retracting the locking mechanism (18) to release the fin (14). The fin (14) is grasped by a notch (20) therein adapted to receive the edge of the fin (14). The piston (18) is retracted by burning a pyrotechnic powder in a cavity adjacent to the piston (18) to fill the cavity with gas and create a pressure differential to force the piston (18) away from the fin.

Abstract: An antenna adapted to apply a uniform electromagnetic field to a volume of gas and including an input terminal for receiving electrical energy into the antenna and an array of radiating elements connected to the input terminal thereof. In the illustrative embodiment, the antenna has four radiating elements. Each radiating element is a conductor wound in a rectangular spiral shape. Each radiating element is connected to the input terminal on one end and an output terminal on a second end thereof. The input terminal is equidistant from first, second, third and fourth output terminals connected to the first, second, third and fourth radiating elements, respectively. The inventive antenna affords a novel method for plasma processing a device including the steps of: mounting the device within a chamber; providing a gas the chamber; and applying an electromagnetic field to the gas via an array of antenna elements disposed relative to the gas to generate a uniform distribution of the plasma.

Abstract: A compact four-way waveguide power divider (10). The inventive power divider (10) includes an input waveguide (11) that terminates at a junction with two adjacent waveguides on opposite sides of the input waveguide. On the opposite side of the junction is a conducting wall into which is built an inductive septum (20). The inductive septum (20) serves to partially match the input impedance of the structure. Second and third inductive septums (22 and 24) are also built into the output arms of the power divider (10). The purpose of the second and third septums (22 and 24) is twofold. In addition to partially matching the power divider's input impedance, the positions of the second and third septums (22 and 24) can be adjusted to equalize the power division between the output arms. Hence, the waves exiting the four output arms of the power divider have highly equalized amplitudes and phases. Further, the phases at the output ports are equalized by adjusting the lengths of the output arms.

Abstract: An equalization system and method. In a most general sense, the inventive equalization system includes first and second filters for filtering an in-phase component of a received signal in accordance with first and second sets of coefficients, respectively. The system includes third and fourth filters for filtering a quadrature component of the input signal in accordance with third and fourth sets of coefficients, respectively. The outputs of the first and third filters are subtracted to provide an equalized in-phase output signal and the outputs of the second and fourth filters are added to provide an equalized quadrature output signal. In the illustrative embodiment the filters are finite impulse response filters and the coefficients are provided by a microprocessor. In accordance with the present teachings, the filters are implemented in a general purpose filter. The delay elements of the filters are calculated in accordance with a mean square error algorithm.

Abstract: A versatile signal processor. The inventive signal processor includes a plurality of filters which are selectively interconnected to provide a variety of digital signal processing functions. In the illustrative embodiment, each filter is adapted to multiply input data by a coefficient. Further, each filter includes adders for accumulating the products. The coefficients are provided by an external processor which configures the general purpose filter to a particular function, such as a general purpose filter, a Hilbert filter, a finite impulse response filter, an equalizer, a beamforming network, a convolver, a correlator, or an application specific integrated circuit by way of example. When interconnected in accordance with the teachings provided herein, these circuits may be used to provide a digital receiver.

Abstract: A multi-resolution feature extraction method and apparatus. In the illustrative embodiment, the feature extractor includes circuitry for receiving and transforming a time variant data signal into a multi-resolution data signal. The multi-resolution data signal is compared to each of a plurality of object templates. The system then generates a feature vector based on a correlation of the multi-resolution data signal to one of the object templates. The multi-resolution feature extraction method employs object templates formed by transforming time variant image data for each of a plurality of objects into a respective multi-resolution template and averaging all templates for each respective object. The method includes steps for transforming an incoming time variant data signal into a multi-resolution data signal, comparing the multi-resolution data signal to each of the object templates, and generating a feature vector when the multi-resolution data signal correlates to one of the object templates.

Abstract: A passive proximity fuze. The inventive fuze (10) is adapted to be mounted on a munition (11) and includes a receiver (16) adapted to lock on to a signal transmitted by a target transmitter (12). The receiver (16) detects a Doppler shift in the signal as the munition approaches the target. When a closest point of approach is reached the Doppler shift changes from increasing to decreasing. The inventive fuze (10) includes a mechanism for detecting this change in the Doppler shift and provides a detonation signal in response thereto. In the illustrative embodiment, the receiver (16) is an FM receiver. The mechanism for detecting a change in the Doppler shift may be implemented with discrete analog circuitry or digital circuitry. In an illustrative analog implementation, first and second resistive/capacitive networks (R1C1 and R2C2) are employed to compute a second derivative of the Doppler shift signal output by the receiver (16).

Abstract: A beamforming system including a multiplier stage for providing a plurality of steered signal terms, each term being a product of an input signal term and a steering signal term. A filter multiplies the steered signal terms by a plurality of respective filter weights to provide a plurality of weighted products. The weighted products are summed to provide an output beam directionally responsive to the steering signal. A microprocessor provides the steering signal terms and the filter weights in response to the input signal and/or user input. In the preferred embodiment, the filter is a reconfigurable, general purpose matched filter configured to multiply a plurality of delayed representations of a respective one of the steered signal terms by a plurality of the weights to provide a plurality of intermediate weighted product terms. The filter further includes a summing circuit for accumulating the intermediate weighted product terms to provide a respective one of the plurality of weighted products.

Abstract: An improved tail fin assembly and method of attachment to a tactical missile capable of high performance motion. The tail fin is formed with a widened inner fin platform portion having a centrally disposed cavity formed by a pair of oppositely disposed walls inclined toward one another. An output control shaft extending from the missile includes a pair of oppositely disposed side walls inclined in a direction similar to the side walls of the cavity. When the tail fin is mounted on the output shaft, the end portion of the output shaft extends within the cavity until the side walls are confronting each other. A pair of fastening screws are advanced into aligned openings, drawing the inclined walls into surface contact to pre-load the tail fin assembly with preset tolerances.

Abstract: An antenna adapted to apply a uniform electromagnetic field with high energy density to a volume of gas. The antenna includes an input node for receiving electrical energy and a first coil for radiating electromagnetic energy into the gas. The first coil is connected to the input node on one end thereof and is grounded on the opposite side to cause flux to flow in a first direction. A second coil is included for radiating electromagnetic energy into the gas. The second coil is also connected to the input node on one end thereof and grounded on the opposite side to flow in the first direction. Multiple number of coils can be added to form an antenna. In an illustrative application, the antenna is used in a plasma processing system comprising a vacuum chamber, a gas disposed within the vacuum chamber, and a dielectric disposed around the vacuum chamber. The inventive antenna is mounted around the dielectric tube and radiates electromagnetic energy into the gas.

Abstract: An antenna that includes a housing having a plurality of walls forming an enclosure, a slot formed in a first wall of the housing, and, a folded cavity formed in a second wall of the housing opposite the first wall. The folded cavity is preferably a compound cavity that includes a first cavity portion and a second cavity portion joined around their entire respective peripheries by a fold or shelf. Any convenient RF transmission line, e.g., a waveguide or coaxial cables, can be used to inject RF energy into the folded cavity. In certain embodiments, both the width and length of the housing are each less than ½ of a free-space wavelength, and the antenna is capable of producing very accurate circular polarization and is capable of handling very high power levels, e.g., 10 kW, thereby making it suitable for high power applications which require extremely compact antenna elements, e.g., wide-scan phased array antennas.

Abstract: A missile guidance system designed to operate on GPS signals in an anti-jamming environment. The inventive system includes first, second and third airborne vehicles (20). A GPS receiver (24) is mounted on each of the three vehicles (20) to receive signals transmitted from spaceborne satellites (14). Each vehicle (20) acts as a pseudo-satellite or ‘pseudolite’. The received GPS signals are processed by a processor (26) to provide a first intermediate signal indicating the position of the vehicle (20). This signal is retransmitted from each vehicle and received by a GPS receiver mounted on a missile. The received intermediate signal is processed on the missile to provide an output signal indicating the position thereof. The pseudolites would be airborne in the vicinity of a target area.

Abstract: An antenna is described which includes a plurality of antennas stacked on top of each other in a compact cavity. Input match and radiation gain can be enhanced by the application of a capacitor and inductor in the feed of the spiral lowest in the cavity. The antenna can fit into a very compact space while providing circular polarization over the desired bands of the antennas that are isolated.

Abstract: A power control circuit for use with a closed loop transmitter such as a cellular telephone. The inventive circuit includes an amplifier for varying the output power level of the transmitter output signal. The amplifier includes an input terminal and a gain control terminal. The transmitter output is fed back to the gain control terminal of the amplifier by a feedback loop. The feedback loop includes circuitry for adjusting the response thereof in response to a loop gain control signal. A control system is included for receiving a power level control signal over a predetermined range of transmitter output power levels and providing the loop gain control signal in response thereto whereby the feedback loop has a linear gain response over the predetermined range of output power levels. In the illustrative embodiment, the system is adapted for use in a mobile station of a cellular telephone system to which a power level control signal is supplied by a base station thereof.