Abstract: A Medium Earth Orbit (MEO) satellite constellation comprising two satellite subconstellations. Each of the two satellite subconstellations comprises three cross-linked satellites. The cross-linked satellites of both subconstellations lay within or near the equatorial plane, and follow a substantially circular orbit. Individual ones of the satellites within each respective subconstellation are offset from each of two adjacent satellites of at least one of the other subconstellations by a predetermined angle. Each of the satellite subconstellations relays communications between a terrestrial node and at least one mission platform in a manner that minimizes the number of satellite links necessary for relaying the communications. At least one satellite from each respective subconstellation is always within a view of the terrestrial node.

Abstract: A Medium Earth Orbit (MEO) satellite constellation comprising two satellite subconstellations. Each of the two satellite subconstellations comprises three cross-linked satellites. The cross-linked satellites of both subconstellations lay within or near the equatorial plane, and follow a substantially circular orbit. Individual ones of the satellites within each respective subconstellation are offset from each of two adjacent satellites of at least one of the other subconstellations by a predetermined angle. Each of the satellite subconstellations relays communications between a terrestrial node and at least one mission platform in manner that minimizes the number of satellite links necessary for relaying the communications. At least one satellite from each respective subconstellation is always within a view of the terrestrial node.

Abstract: A high gain Cassegrain reflector antenna system is disclosed for use in a RF signal receiving application. In one embodiment of the invention the antenna is a single parabolic reflector antenna having a plurality of feeds, while in another embodiment the RF signal is received by a number of parabolic reflector antennas. Each received RF signal component is separately amplified to produce corresponding individual amplified signals which are then summed to produce a summation signal. A phase difference between the summation signal and each individual amplified signal is determined, and each individual amplified signal is then phase adjusted until it is in a substantially coherent phase relationship with the summation signal. The phase adjustment compensates for phase displacement errors occurring due to, by example, an effective sector displacement error of a primary reflector of the Cassegrain antenna assembly.

Abstract: This invention pertains to: a method for controlling the monitoring of broadcast messages of traffic information, and reporting to a user, traffic information that relates to a set of user-specified routes of travel; and also to a travel route information monitor that operates in accordance with the method. The method includes a first step of programming information into a controller (1). A first portion of the programmed information specifies a time. A second portion of the programmed information specifies a set of geographical routes of travel comprising a primary route and at least one alternative route. A next step includes initiating the receiving of broadcast messages of traffic information at a time that is a function of the time specified by the first portion of the programmed information. A next step includes screening received broadcast messages to collect traffic information that relates to any of the routes of travel specified by the second portion of the programmed information.

Abstract: Occulting apparatus for use with an image generator that provides for multiple-level occulting of image data. The occulting apparatus comprises a mask buffer and control logic for processing image data to construct and store an obscurance mask in the mask buffer. Foreground entities contained in the image data are logically ORed into the mask buffer until the entities extend beyond a predefined range from a predetermined image viewpoint. Thereafter, the mask is used by the control logic to reject entities contained in subsequently processed image data that are fully obscured by the foreground entities comprising the obscurance mask. The control logic includes an obscurance manager, a region processor, an object processor, a polygon processor, and insertion logic. The obscurance manager is a controller for building and applying the obscurance mask to the image data.

Abstract: This invention pertains to a method for producing high power microwave transmission signals conveying one of a plurality of symbols, wherein a symbol represents a plurality of bits, and also to a modulating array transmitter that operates in accordance with the method. The method includes a first step of applying j bits to a data storage device to address the data storage device to output N bits to N/2 QPSK modulators. Each of the N/2 QPSK modulators receives a subset (a pair) of the N bits. Each of the bit pairs specifies one of up to four phase shifts. Within each of the N/20 PSK modulators, a next step phase modulates a reference (e.g., local oscillator) signal in accordance with a phase shift specified by the received pair of bits. A next step amplifies the outputs of each of the N/2 QPSK modulators to produce respective amplified QPSK modulated signals.

Abstract: An ultrasound imaging system for generating high resolution, three-dimensional images of the body for medical imaging. The system includes a housing with a rotatable disk at one end having an aperture therein and a plurality of pairs of ultrasonic transducers disposed around the periphery thereof. A flexible member encloses the housing and a fluid filled cavity disposed in the housing in which the transducers are immersed. An ultrasonic transmitter is coupled to the aperture for transmitting ultrasonic energy by way of the aperture, fluid filled cavity and flexible member. A receiver is coupled to the ultrasonic transducers and a processor is coupled to the receiver for sequentially processing reflected ultrasonic energy received by the pairs of ultrasonic transducers to produce a high resolution, three-dimensional image of the body. The system forms a synthetic aperture using the moving ultrasonic transducers.

Abstract: A system and method for acquiring a satellite with an antenna using a computing portion which determines the variation between the actual orientation of the antenna and an optimum orientation to acquire a satellite. The deviation is computed by: determining the actual orientation of the antenna with respect to true North and producing a first signal indicative thereof; determining the location of the antenna on the Earth and producing a second signal indicative thereof; determining the elevation of the satellite with respect to the location of the antenna and producing a third signal indicative thereof; determining the azimuth of the satellite with respect to the location of the antenna and producing a fourth signal indicative thereof; and using log data for the satellite along with the first, second, third, and fourth signals to compute the position of the satellite relative to the antenna and produce a signal indicative of the deviation.

Abstract: A locking device for quickly attaching a wing to and removing the wing from a body of a missile, for example. The locking device is disposed in an opening in the wing and is adapted to secure the wing to the body of the missile using its attachment rail. The locking device comprises a rotatable cam, a rotatable cam follower for locking the wing to the attachment rail, and a cam latch for locking the cam follower in place. The cam has a opening disposed therein that is suitable for accepting a locking tool, such as an Allen wrench, for example, that is used to rotate the cam, and hence the cam follower, to attach the wing to and remove the wing from a m-fissile. A plurality of springs are respectively employed to retract the the cam follower when the locking device is disengaged, and to secure the cam latch in place when the cam follower is locked in place.

Abstract: A phased array antenna (PAA) that is particularly adapted to accommodate communications with low earth orbiting (LEO) satellites includes three antenna faces which comprise a phased array of radiating elements, each antenna face is triangular and the three faces form a triangular pyramid. Each triangular face has a height h and a base length B. B and h are chosen to optimize the antenna's gain variation with beam elevation angle to compensate for the path losses dependent on beam elevation angle. At low elevation, increased free space loss in incurred due to longer range to a low earth orbiting satellite, and more rain and atmospheric loss is incurred due to longer path through the atmosphere compared with the losses at higher elevations or at zenith. Since the intrinsic shape compensates for the elevation dependent losses, the PAA design minimizes total array area compared with other known geometries and thus exhibits lower cost.

Abstract: A method for treating surfaces of carbon based materials produces a layer of hafnium carbide with no significant change of the location of the surface or the dimension of the part being treated. A slurry containing elemental hafnium is applied to this surface. The surface is heat treated in a vacuum furnace, causing the hafnium in the slurry to form an HfC layer within the material, and remove all other slurry materials from the surface. In a variation of the method, the slurry may also contain silicon and chromium to catalyze the reaction. The treated surface exhibits improved properties for components of high temperature gas flow handling systems. The method is useful for valves and ducts having complex internal surface geometries.

Abstract: A quick release mechanical attachment that forms part of a missile loading system for loading a missile onto a launch rail disposed on a vehicle. An electric crane mechanism, comprising a boom and hoist, is used to lift the missile adjacent the launch rail, and the quick release mechanical attachment is used to interface the electric crane to the deck of the vehicle. The quick release mechanical attachment comprises a base that includes a body having an internal bore and a counterbore. An electrical contact arrangement comprising a plurality of insulated conductive members is disposed in the counterbore. A plurality of electrical connectors are coupled to the conductive members, and first securing members are provided for securing the electrical contact arrangement in the counterbore. The base in its assembled condition has a predetermined internal taper. The electrical contact arrangement comprises a plurality of nonconductive spacers that surround the conductive members.

Abstract: Apparatus that provides working storage for large image and data processing systems. The apparatus comprises a computer bus, a high speed backplane bus, a local area network, a central processing unit coupled to the computer bus, an Ethernet local area network interface coupled between the computer bus and the local area network, a plurality of bidirectional input/output interface cards coupled to the computer bus and the backplane bus, and a plurality of disk modules coupled to the computer bus and the high speed backplane bus. Each interface card comprises a plurality of bidirectional input/output ports coupled to a plurality of user workstations, a fiber optic interface, and a FIFO buffer. Each disk module comprises a plurality of storage units, one of which provides for storage of parity bits and the remainder of which provides for storage of data, and a distribution card coupled to the plurality of storage units.

Abstract: An equalizer employed with a receiver for cancelling an interfering signal due to low cross-polarization isolation. The present equalizer provides a simple and inexpensive cross-polarization interference cancellation system. The equalizer uses an error signal generated in an adaptive baseband equalizer to determine the magnitude of an interfering signal and inputs a cancelling signal to the co-polarized channel until power in the error signal derived from the adaptive baseband equalizer is minimized. In the equalizer, the determination of the magnitude of the interfering signal is performed at baseband (after demodulation but prior to data detection) and the cancellation is performed at RF, prior to dispersive microwave elements. The equalizer enhances the capability for transmitting two unique signals in the same frequency allocation on orthogonal polarizations. The equalizer operates even if the modulations and data rates on the two channels are different.

Abstract: An image generator architecture in which tri-level fixed interleave processing provides medium grain parallelism for polygon, tiling, and pixel operations. Input data at each stage are divided into spatially distributed subsets that are interleaved among parallel processors using a fixed, precalculated mapping that minimizes correlation of local scene complexity with any one processor. The present tri-level fixed interleave processing architecture divides a processing task into a pseudo-random, fixed interleaved pattern of regions that are assigned to different processors. Each processor processes many of these randomly located regions. The assignment of processors to regions is a fixed repeating pattern. The highest level of fixed interleave processing is the allocation of fixed-size database regions (area modules) to polygon processors. The next level relates to image sub-region fixed interleave processing.

Abstract: A programmable PCM/TDM demultiplexer including an FA function unit including Frame Alignment Logic (FAL) hardware controlled by a Programmable Frame Alignment Controller (PFAC), and accompanied by a DECommutation and dejustification (DEC) function unit including Output Logic Hardware (OLH) controlled by a Programmable Decommutator Sequencer (PDS) controlled in turn by a Programmable Decommutator Sequencer Controller (PDSC).

Abstract: A missile loading system for loading a missile onto a missile launcher disposed on a vehicle. The missile comprises fore and aft missile hangers that each have upper and lower hooks that have a predetermined separation distance therebetween. The improvement provided by the present invention comprises a launch rail disposed on the missile launcher that has two cut-outs disposed a predetermined distance apart that equals the separation distance between the fore and aft missile hangers on the missile. A plurality of load detent mechanisms (fore and aft) are provided that each comprise a body having the shape of the launch rail, and a lip by which the missile is secured, and an opening disposed therein. A plurality of holes are disposed in the body that are used to secure the load detent mechanism the cut-outs in the launch rail. A spring-loaded member having the shape of the launch rail is rotatably secured in the opening of the body.

Abstract: A vector modulator that sums outputs of a plurality of quadrature-phase-shift-key (QPSK) modulator elements, each controlled by two digital input signals and a single local oscillator. The local oscillator provides a periodic sinusoidal output signal, and the modulator elements process the periodic sinusoidal output signal and the digital input signals. The state of the respective digital input signals determines which of four phase states are present at the output of the QPSK modulator. A plurality of summing devices are coupled to outputs of the modulator elements, and one summing device provides an analog constellation output signal of the vector modulator. A plurality of attenuators are provided for amplitude weighting output signals from the plurality of modulator elements.

Abstract: A self-contained, self-configurable cascadable pipelined processor chip (160) is diclosed. The chip contains a computation section (FIGS. 1a-1d) which consists of various types of computation circuits (20-42) that can be software-interconnected in any desired configuration by a set of multiplexers (44-52) whose settings are under the control of a control section (FIG. 2 ). The control section consists of various types of control circuits (60-76) which are also software-interconnectable in any desired configuration under program control. The chip (160) is configured by a very long instruction word and then executes the algorithm defined by that configuration iteratively until stopped. The chip (160) can be programmed to reconfigure itself in response to computation results or other selectable parameters, either in accordance with internally stored configurations or in accordance with configuration information stored in an external random access memory (56, 58).

Abstract: A transversal filter allrate equalizer for use at intermediate frequency. The equalizer includes a signal divider coupled to receive the intermediate frequency input signal and a transversal filter comprising a plurality of analog delay lines and a plurality of multiplying circuits. The plurality of analog delay lines are coupled to the signal divider for producing a time-shifted replica of an intermediate frequency input signal. The plurality of multiplying circuits are respectively coupled to the delay lines for weighting the time-shifted replicas of the input signal by complex numbers, W.sub.i. A signal combiner is coupled to the plurality of multiplying circuits for recombining the time-shifted and weighted replicas of the input signal to produce an equalized output signal. The delay lines operate at an intermediate frequency, and produce a time delay for the modulation and a phase shift for the carrier. The phase shift may be compensated for by adjusting the phases of the tap weights, W.sub.i.