Abstract: A precise, spacecraft camera image navigation and registration system and method wherein a computer 36 on-board the spacecraft and a ground system comprising at least two ground stations precisely compute image navigation and registration data from precise data measurements. The computer on-board the spacecraft (spacecraft control system) uses precise star tracker, gyro, and earth sensor attitude data to precisely point the spacecraft and the camera. The ground system utilizes precise star measurement data from the camera and range data from the ground stations time tagged with GPS precise clock data. The ground system uses these precise measurements to determine precise orbit and attitude coefficients and uploads these coefficient to the spacecraft. The computer on-board the spacecraft uses these precise coefficients to generate and apply precise signals to compensate for slow orbit and attitude variations and register camera images in real time.

Abstract: A system and method for RF autotracking multiple antennas to compensate for disturbances experienced by the antennas. The system and method uses two control algorithms implemented in fast and slow controllers and sums the result for each antenna that is tracked. One (fast) control algorithm corrects for rapid, common mode disturbances such as spacecraft motion disturbances, while the other (slow) control algorithm corrects for slower disturbances, such as thermal distortion, that do not affect all antennas in the same manner.

Abstract: RF signal nulling and loss of RF lock (i.e., loss of a communications or command link) is resolved by changing the phase of signals derived from first and second (+Z and -Z) antennas so that they add in phase instead of canceling. This is accomplished automatically by using a computer or processor to measure the RF signal level output by a receiver and change the phase of the incoming signal using a phase shifter to achieve the highest level. A squelch circuit in the receiver is used to determine the maximum obtainable RF signal level. The squelch level is compared in a computer to a threshold when the system looks for a higher squelch level. The phase of the phase shifter is changed using a computer to maximize the received signal level. A feedback loop from the receiver through the computer to the phase shifter provides a path to shift the phase of the incoming RF signal in one of the paths so the respective signals add instead of cancel, which eliminates the signal nulling problem.

Abstract: A modulating array transmitter employing a method that provides for improved power efficiency. The present inventors have observed that for symbols where pairs of power amplifiers of the modulating array transmitter are driven with opposing phases, the pairs of power amplifiers may both be keyed off to conserve prime power. The transmitter has a lookup table for providing a plurality of digital input signals and an on/off keying bit input signal, a plurality of quadraphase power elements that each comprise a modulator coupled to the lookup table and to a reference signal source, and a high efficiency amplifier coupled to a power source. A power combiner combines outputs of the plurality of power elements to produce a quadrature amplitude modulated (QAM) output constellation containing a plurality of symbols. The on/off keying bit input signal is used to key off selected pairs of power amplifiers that are driven with opposing phases and produce certain of the symbols of the constellation.

Abstract: A modulating array transmitter that employs a power recycling method and power recovery circuit. The modulating array transmitter uses a plurality of multiphase power stages to generate a multi-point QAM constellation. Outputs of the plurality of multiphase power stages are combined in an output power combiner. The output power combiner uses terminating resistors on its difference power port(s). Using the present invention, power normally dissipated in the terminating resistors is recovered. Instead of dissipating this difference RF power, the present invention converts this power to DC power using rectifiers of the power recovery circuit. The rectified DC power may be used to supplement the DC power required for power amplifiers in the multiphase power stages. In this manner, the difference power is "recycled" and thus may be reused.

Abstract: Apparatus for securing a relatively small diameter wire or tube, and in particular, a small diameter guide wire and an angioplasty catheter that are inserted into a patient during an angioplasty or similar operation. The apparatus has a flexible member comprising a base portion, first and second abutting flexible portions attached to the base portion, and an opening having a diameter suitable for loosely securing the wire and catheter formed at an interface between the abutting flexible portions. An adhesive layer, typically having a backing layer, is disposed on the bottom of the flexible member. A preferred embodiment of the apparatus may be formed such that the first and second flexible portions extend outward in lateral directions away from the top of the opening. First and second base portions are connected to an external wall of the opening by flanges. The respective flexible portions and base portions have transverse ribs to provide added strength.

Abstract: An intermediate frequency adaptive cross polarization interference canceler for processing an interfering cross polarization signal distorted by dispersion. The canceler has right and left inputs for respectively receiving right and left polarized IF input signals. A plurality of serially coupled complex multiplier and control stages respectively process the right and left polarized signals to provide controlled amounts of coupling between them to cancel cross polarization interference therebetween. A plurality of delay lines add predetermined time shifts to the right and left polarized signals between stages, and which forms a transversal filter having a predetermined number of taps. The canceler outputs right polarized IF output signal and a left polarized IF output signal having substantially no cross polarization interference therebetween. A preferred embodiment of the adaptive cross polarization interference canceler uses a compensating five-tap transversal filter disposed in the cancellation path.

Abstract: Improvements to amplitude phased keyed digital communications systems and to the processing of amplitude phase keyed symbols transmitted over radio frequency channels. The present invention provides for an amplitude phased keyed digital communications system including an adaptive baseband equalizer, a digital symbol recovery circuit in accordance with the present invention, and a quadrature demodulator. The adaptive baseband equalizer receives amplitude phased keyed signals and outputs in-phase and quadrature digital amplitude values corresponding to the received amplitude phased keyed signals. The digital symbol recovery circuit comprises a programmable addressable random access memory that stores a plurality of eight bit words comprising decoded symbol sets of the received amplitude phased keyed signals, and outputs the decoded symbol sets in response to addresses corresponding to the in-phase and quadrature output signals.

Abstract: A switch remoting system for extending the function of an existing wired switch in a residence or other building, so that, in its extended function, the switch controls AC power available at one or more additional AC outlets. The basic system comprises two plug-in modules including a control unit and a remote switching unit. The control unit is plugged into an AC outlet controlled by the switch whose function is being extended. When that switch is actuated, the AC power transition and the resulting "on" or "off" power state is sensed and corresponding encoded switching control signals are generated and relayed to the remote switching unit. There, the switching control signals are decoded, and actuate an internal AC switch that controls AC power to an integral AC outlet receptacle in the remote switching unit. A lamp or other device plugged into the AC receptacle of the remote switching unit is thereby switch controlled by action of the switch whose function is being extended.

Abstract: An improved retaining mechanism for use with a pierced earring having an ornament having a stem. The retaining mechanism has a base with an opening therein through which the stem of the earring passes, a cylindrical tube extending from the base with threads on an external surface. An inner wall of the tube tapers from its open end toward the base. A cap is provided that has a closed end with an opening therein through which the stem of the earring passes. The cap has threads formed on an inner surface that mate with the threads on the external surface of the cylindrical tube. A tapered member extends from the closed end of the cap and is tapered along its exterior wall. The external taper of the tapered member substantially matches the internal taper of the cylindrical tube. The tapered member has a slot formed in its wall.

Abstract: An optical technique (apparatus and method based on the use of power spectral density analysis of spectroscopic multiple angle reflection and transmission data is disclosed. The apparatus and methods measure optical constants (n, k) and thicknesses of single and multilayer films. The apparatus and method provide for index determination with high accuracy (0.00001).

Abstract: A high power RF transmitter that uses high power modulators that perform quadrature amplitude modulation (QAM) on a carrier signal after power amplification that is performed in the RF carrier source. The present invention transposes the locations of the modulators and power amplifier, and thus directly modulates a high power carrier signal. An RF carrier source generates a high power RF carrier signal that is split by a power splitter. A lookup table containing 2.sup.B words by K bits receives transmit data and mapping data and generates K-tuple modulating data. A plurality of phase key modulators are respectively coupled to outputs of the power splitter and to the lookup table and phase key modulate each of the signal components of the carrier signal using the K-tuple modulating data. A power combiner is coupled to outputs of the phase key modulators for outputting a high power QAM constellation from the transmitter.

Abstract: A communications system employing a telestation that uses a computer to provide command and data handling, a GPS receiver to provide position, time, and attitude information, and a transceiver to provide two-way wireless digital communications. The computer is coupled to an instrument, measuring device, or payload, and is controlled to relay data generated thereby to a user. Commands and data are uplinked and downlinked to the telestation by way of a satellite network, such as a Globalstar network. The telestation provides a user with real-time command and control of globally distributed instruments. This capability may be used terrestrially for gathering information (e.g., science, environmental, etc.) in remote or inhospitable locations, or where logistical support is inadequate. An in-orbit version may be used for spacecraft or satellite instruments 15, allowing investigators instant access to the instruments during all phases of a mission.

Abstract: A Ku-band integrated pre-distortion type linearizer bridge circuit for use in linearizing the performance of a traveling wave tube amplifier. The linearizer bridge circuit comprises linearizer bridge that embodies a phase shifter and a fixed delay in a linear arm, and a Schottky diode distortion generator and a PIN diode attenuator in a nonlinear arm. The output of the linearizer bridge is coupled through an output amplifier and an output attenuator. The RF output signal from the linearizer bridge circuit is coupled to the traveling wave tube amplifier. A control circuit is coupled to the phase shifter, the nonlinear Schottky diode distortion generator circuit, and the PIN diode attenuator, and receives on and off input command signals, and outputs a bilevel telemetry signal that is used as a mode indicator for ground command control.

Abstract: A software-controlled select and test system for use with a spacecraft. The system reduces the assembly, integration, test time and improves performance of the payload and spacecraft by optimizing the performance using standardized algorithms. The system also reduces the DC power required by the spacecraft, and the thermal dissipation, battery size, solar array size and mass of the spacecraft. This is achieved by optimizing traveling wave tube amplifiers for each channel instead of meeting minimum power requirement over the entire range, wherein most channels have excess power. A serial interface adapter performs the optimization functions via software.

Abstract: A signal conditioner comprising several embodiments of transversal (FIR) filters that utilize symbol addressed multiplier lookup tables. In particular, five embodiments in accordance with the principles of the present invention are described. The present invention generates a predistorted waveform within the transversal filter that provides for compensation for the effects of nonlinear amplifiers and intersymbol interference. The present invention may be employed to digitally generate an arbitrary baseband waveform that represents a limited alphabet of symbols. The present invention dramatically simplifies the implementation of FIR filters where the application of the FIR filter is to provide a transversal filter function for waveforms that represent symbols. The degree of simplification is related to the number of bits that define the size of the symbol alphabet as compared to the number of bits required to adequately represent a digital sample of the waveform.

Abstract: An image processing apparatus and method that completely removes blocking artifacts from a compressed and restored digitized image. A compressed image is formed by windowing pixel data with a smooth window (discrete cosine transform) and then folding (wrapping) the windowed pixel data to form a modified image that is the same size as the original image. The wrapped and folded image is thereafter processed using a conventional discrete cosine transform and coder to produce the compressed image. To restore the original image, an inverse discrete cosine transform is used to process the compressed image, then the pixel data is unfolded (unwrapped), windowed, and combined to form the restored image. The present invention may be used to process data, such as voice signals, and images other than radiological images. The transform used in the present invention may also be a Fourier transform, for example.

Abstract: A fuzzy logic load management controller for use with a computer image generator. The load management controller is used use with a computer image generator having a plurality of inputs and a plurality of outputs, and includes an adder that couples inputs to the image generator. The load management controller comprises a fuzzy logic controller disposed in a feedback loop between the output of the image generator and the adder. The load management controller includes a fuzzy logic inference engine, a set of membership functions coupled to the inference engine, and a rules database coupled to the inference engine that includes a set of if-then rules that specify the response of the fuzzy logic controller to inputs applied thereto. The fuzzy logic controller provides for load management of the image generator that gracefully degrades a viewed scene, keeps the image update rate constant, and renders important objects in the viewed scene.

Abstract: A programmable, closed-loop control system that provides for control under normal and seismic conditions. The present system integrates monitoring and control functions and provides for reconfigurable control of these functions. The seismic monitoring and control system optimally controls valve-type fluid flow systems. Separate control algorithms may be programmed by a user to control the system under both normal and seismic conditions. In its broadest aspects, the present system comprises a sensor for sensing a predetermined condition and for providing output signals indicative thereof, a switch, and a programmable controller coupled to the sensor and switch. The controller includes a seismic sensor for detecting a seismic disturbance and providing output signals indicative of the seismic disturbance.