Abstract: A signal processing system and method for improving reception of plural signals received at an antenna array in a wireless communication system by increasing the carrier-to-interference plus noise ratio and by decreasing signal envelope variance of each of the plural signals using single or multiple stage subspace projection and a constant modulus beamformer. Each of the stages separate and optimize one of the signals and projects the remaining signals (if present) to the subspace of the next stage. In the method and system the plural signals received at each antenna are converted to baseband in a wideband RF downconverter. Received signals are thereafter provided in digital form to the constant modulus beamformer where each stage of the beamformer separates one of the plural signals from a stage input so that a stage output has the remaining ones of the plural signals, and projects the stage output onto a subspace of the remaining signals in the next stage.

Abstract: An antenna for a land-based, mobile radio communication system, having a reduced size and shape, includes three, flat antenna dielectric panels, each covering one hundred, twenty degrees of azimuth. On each dielectric panel is formed two, interleaved microstrip antenna arrays having narrow vertical beam width. One of the antenna arrays receives signals and the other antenna array transmits signals. The receive array is circularly polarized. The panels are mounted in a triangular configuration about a central mast and a cylindrically shaped radome encloses the dielectric panels.

Abstract: A hole preparation apparatus for back drilling, upsizing and reaming mating precision holes. The apparatus includes three main sections--a tubular body section, a base and a drive shaft assembly.The drive shaft assembly includes an upper portion sized to be received in the chuck of a conventional pneumatic or electric drill, a lower portion sized to be received in the bore of the tubular body. An internal threaded drill receiving socket is disposed at a lower end of the lower portion of the drive shaft. A coil retractor spring is located in the central bore of the tubular body section. A removable pilot drill is received in the drill receiving socket. A pilot drill bushing is located in the bottom end of the bore of the tubular body. An opener drill is changeable with the pilot drill and is received in the drill receiving socket when the pilot drill is removed. An opener drill bushing, is changeable with the pilot drill bushing.

Abstract: A cable retractor comprising interconnected restrainer segments attached end-to-end by pivot pins, such that the entire structure is foldable into a small space. A fiber optic cable is attached to restrainer segments in a manner such that the total path length of the fiber optic cable does not substantially change as the retractor is unfolded to an extended position from a folded position.

Abstract: A tool for removal of rivets includes three main sections--a tubular body section, a base, and a drive shaft assembly. The drive shaft assembly includes an upper portion to be received in the chuck of a rotational source of power and a lower portion to be received in the bore of the tubular body. An internally threaded drill receiving socket is disposed at a lower end of the lower portion of the drive shaft. The body section includes a coil spring for retracting the drill and a drill stop bushing for limiting the depth of penetration of the drill bit into the rivet. The base includes an upper disc and a larger diameter lower disc and three equally spaced tubular legs connect the upper disc to the lower disc. The bottom of the base includes a non-slip polymeric pad for contacting a work surface surrounding the rivet and stabilizing the cutting path of the drill.

Abstract: Apparatus and a method for providing real estate agents, persons relocating to another home or acquiring an interest in a property, and providers of home insurance, with an audio-visual presentation of a property supplied over existing cable, telephone, ISDN or other types of broadband network facilities. The audio-visual presentation is mode on a computer monitor from a database containing a visual walkthrough and a textual description of the property and surrounding areas.

Abstract: An apparatus for applying non-gravitational pressure to a surface includes a frame structure having a longitudinal axis, a pair of connecting members coupled to the frame structure along parallel axes normal to the longitudinal axis of the frame structure, vacuum fasteners coupled to the connecting members to secure the frame structure on an underlying surface, a vacuum pump mounted on the frame structure for activating the vacuum fasteners and a positive pressure pump mounted on the frame structure for inflating a collapsible diaphragm to apply pressure to the underlying surface. The apparatus is useful for applying doublers to aircraft repair localized damage.

Abstract: An optical system for scanning a light beam across an object where the light beam is double reflected by the reflection surfaces of a rotating polygonal mirror. Beam expander optics are included in the light path for the light beam following the first reflection by the polygonal mirror to magnify the beam diameter to fill the length of the reflective surface of the polygonal mirror at the second reflection. The beam expander optics further include lenses for demagnifying scan angle in the light beam following the first reflection. The lenses of the beam expander optics are formed with a Petzval curvature (third order Seidel aberration) to correct for the distortion induced in the optics image plane by the longitudinal shift in the entrance pupil position at the first reflection as the polygonal mirror rotates.

Abstract: A method for selecting tie point locations within a series of overlapping images. Initially the series of images are ordered to maximize the potential for successful phase correlations between adjacent images. Adjacent pairs in the ordered images are then phase correlated to determine the translational offsets between adjacent pairs. The overlapping regions in adjacent pairs are assessed for normalized cross correlation and initial candidate tie points are selected within the regions at a reduced resolution. The initially selected tie points are then phase correlated at full resolution and any surviving candidate tie point locations are further refined to sub-pixel accuracy.

Abstract: A communications system programmable to operate at a selected one of multiple frequency ranges and any one of a plurality of modulations schemes and data rights including an open architectural bus line for linking a plurality of board level units. A single board receiver exciter operates to receive and transmit signals at a plurality of frequencies and contains means for interfacing the single board receiver exciter with the open architectural bus line. A single board modulator demodulator allows for modulation/demodulation and for encoding/decoding of signals. The single board modulator demodulator also includes means for interfacing with the open architecture bus lines so that instruction and programming commands may be received. A single board processor multiplexer controls operations of the single board receiver exciter and the single board processor multiplexer over the communications link created by the open architecture bus line.

Abstract: A method and apparatus for controlling the temperature of a device, wherein said method and device includes a plurality of thermoelectric coolers with independent temperature feedback control loops monitors and controls the temperature of a device. One thermoelectric cooler coupled to the package of the device maintains a desired temperature of the package by utilizing a first independent control loop. A second thermoelectric cooler coupled to the device maintains a desired temperature of the device by utilizing a second independent control loop. The operating temperature of the package of the device is maintained as the temperature of the environment varies.

Abstract: A method and apparatus determines the location of a signal transmitter located at an unknown location by using externally-induced intermodulation distortion emitted from the signal transmitter. A transmitter locator emits an interrogation signal having a frequency that is offset from the frequency of the signal emanating from the signal transmitter. The interrogation signal and the carrier signal of the signal transmitter are "mixed" within the signal transmitter to form an intermodulation product signal. The intermodulation product signal having a different frequency is then radiated from the unknown signal transmitter. A receiver tuned to the frequency of the intermodulation signal detects the returned signal and a processor determines the range and direction from the transmitter locator to the location of the signal transmitter.

Abstract: A very high speed counter system of operating at frequencies of up to around 800 MHz provides timing measurements with accuracies on the order of (1/f) seconds where f is the frequency of operation. The least significant bit of the counter operates at the given frequency of a first clock signal while the other higher order bits operate at a second clock signal where the second clock signal is one-half the frequency of the first clock signal and is inverted. Carry lookahead circuits connected between stages of the second counter operate in conjunction with the clocking scheme to produce a high speed and accurate counter.

Abstract: A relative GPS landing system is provided for approach and landing of aircraft where an accurate site survey of the GPS platform is unavailable. Data containing information on all GPS satellites in view is uplinked from a ground station to an aircraft. A relative solution is derived at the aircraft. Based upon the calculated solution, aircraft guidance signals are generated for approach and landing of the aircraft at a desired point.

Abstract: A liquid coolant heat exchange system for use in semimonocoque aircraft includes an arcuate planar heat sink fixed along a radius of curvature R.sub.1 by forming members, a flexible arcuate planar spreader plate having a radius R.sub.2, such that R.sub.1 >R.sub.2, a heat exchange tube for transferring heat from the liquid coolant to the heat sink and means for attaching the spreader plate to the forming members to hold the spreader plate in contact with the heat sink.

Abstract: A method and apparatus for encoding and decoding data on navigation signal pulse pairs utilizes pulse position modulation (PPM). The pulse interval between a first pulse and a second pulse of the pulse pair is varied depending on whether the logic value of the data to be encoded is a logic "0" or a logic "1". A tri-graph encoding process converts the raw input data into encoded input data. Each input data bit is encoded into three bits with each bit having the same logical value as the input data bit. The encoded input data is then encoded on the navigation signal using a pulse position modulation (PPM) technique. A decoder recovers the encoded data and provides an error correction process for high data integrity that corrects certain bit errors that may occur during the transmission and reception of the data on the navigation signal. The error correction process detects and corrects errors such as a missing bit, an extra bit or a bit error.

Abstract: A communications system programmable to operate at a selected one of multiple frequency ranges and any one of a plurality of modulations schemes and data rights including an open architectural bus line for linking a plurality of board level units. A single board receiver exciter operates to receive and transmit signals at a plurality of frequencies and contains means for interfacing the single board receiver exciter with the open architectural bus line. A single board modulator demodulator allows for modulation/demodulation and for encoding/decoding of signals. The single board modulator demodulator also includes means for interfacing with the open architecture bus lines so that instruction and programming commands may be received. A single board processor multiplexer controls operations of the single board receiver exciter and the single board processor multiplexer over the communications link created by the open architecture bus line.

Abstract: There is described a vehicle door assembly with shear layer control for controlling the airflow in and around an aperture in the vehicle fuselage. The vehicle door assembly consists of an upper door and a lower door, both slidably mounted to the exterior surface of the vehicle fuselage. In addition, an inner door is slidably mounted beneath the upper door. Beneath the inner door is an aperture assembly having an aperture opening positionable to be substantially flush with the exterior surface of the vehicle fuselage. Also provided are means for positioning the aperture assembly in an upward and downward direction in relation to the vehicle fuselage.

Abstract: An RF antenna and an associated receiver are proximately located in an integrated antenna/receiver unit thereby eliminating the need for baluns and inter-component cabling characteristic of prior designs. Integration of the receiver with the antenna provides for improved sensitivity as the need for utilizing signal dissipating and noise introducing cables and baluns to transmit the signal received by the antenna to the receiver is eliminated. Direct coupling of the antenna and receiver on a single gallium arsenide integrated circuit maintains balanced impedance from the antenna to the receiver.

Abstract: A liquid coolant heat exchange system for use in semimonocoque aircraft includes an arcuate planar heat sink fixed along a radius of curvature R.sub.1 by forming members, a flexible arcuate planar spreader plate having a radius R.sub.2, such that R.sub.1 >R.sub.2, a heat exchange tube for transferring heat from the liquid coolant to the heat sink and means for attaching the spreader plate to the forming members to hold the spreader plate in contact with the heat sink.