Abstract: A biphase shift keyed modulated carrier is input to an analog delay line having a plurality of sampling taps time spaced along the line. The modulated input carrier is sampled at a rate four times the carrier frequency to produce amplitude samples of the input. The taps of the delay line are divided into two groups comprising alternate tap sets and the amplitude samples of each group are summed for decoding the I and Q channels of a modulated carrier. The summed signal of each of the channels is input to an individual sample and hold circuit which aliases the carrier frequency to baseband. The output of the first sample and hold circuit of each channel is provided to a second sample and hold circuit for the respective channels. The second sample and hold circuit of each channel is clocked at a data rate derived from a bit timing loop.

Abstract: A system for monitoring the operation of a multichannel receiver includes a channel monitor coupled to the sync separator of the receiver for collecting and transmitting channel information to a central collector station. The collector station selectively responds to one of a plurality of channel monitors to record, in sequential order, channel information. Each of the channel monitors is similar and includes a synchronizing pulse generator triggered by the vertical synchronizing pulse from a receiver to generate a match recognize pulse when a frequency coupled to the receiver from the monitor and the channel frequency have a preestablished relationship. To generate the match recognize pulse a counter provides signals to a tuning matrix that controls a frequency synthesizer or plurality of oscillators for generating the frequency coupled to the receiver for the match evaluation. Also, the counter activates a data encoder that provides channel information to the collector station.

Abstract: Acquisition of a carrier frequency lock and a symbol timing lock is efficiently achieved during the preamble of a data signal in a time division multiple access communication system by first operating the system in an acquisition mode and subsequently switching to a data recovery mode. In the acquisition mode, an input signal is passed through a transversal correlator and frequency multiplied by a factor of two. The multiplied signal is used to control a local oscillator for demodulating the carrier signal. Also in the acquisition mode, the output of the transversal correlator is envelope detected and applied to a symbol timing loop that produces a symbol timing signal. Upon the detection of a symbol timing lock, a lock detector switches the system to the data recovery mode. In the data recovery mode, the input signal is frequency multiplied by 4 and used to control the local oscillator for demodulating the input signal.

Abstract: A test system and method for in line testing of shock suppressor shut-off valves is provided. Vacuum and fluid canisters are mounted to a backpack that can be carried by maintenance personnel to the operating locations of shock suppressors. The fluid canister contains a fluid for being driven through the shut-off valves of the shock suppressor during testing. Fluid lines interconnect the canisters and the shock suppressor. A valve assembly is disposed within the fluid lines for regulating the rate of flow of the fluid from the fluid canister to the shock suppressor. The system further includes structure disposed within the fluid lines for evacuating the fluid lines and the valve assembly prior to testing of the shut-off valves.

Abstract: A servo valve controls the rate and direction of flow of a hydraulic fluid from a fluid power system to impart reciprocating motion to the piston of a hydraulically driven motor. An outer sleeve member of the servo valve has entry and exit ports connected to the source of fluid power and motor control ports connected to the hydraulically driven motor. A slider member is positioned within a cylindrical opening through the sleeve member and includes fluid chambers within the slider for alternating the direction of fluid flowing to the hydraulically driven motor by rotating the slider member. The rate of fluid flow is controlled by the lateral movement of the slider within the sleeve member.

Abstract: A radio receiver is disclosed which measures the statistics of an interfering narrow band noise signal and from these statistics generates a function which when mixed at baseband with a data signal combined with the narrow band noise reduces the interfering effect of the noise signal. The interference eliminating function is generated by processing signals representing an approximation of the data, the covariance of the narrow band noise interference, the noise figure for the receiver and the amplitude of the data signal. As the function is generated it is input to a mixer together with the combined narrow band noise and data signal. Iterated processing improves the estimation for the noise statistics thereby improving the approximation for the resulting data signal. This further enhances the solution for the noise elimination function thereby still further improving the desired data signal, thus creating a positive improving feedback loop.

Abstract: An apparatus for axial support and shock suppression of a pipe includes a walking beam having an inner portion secured to the pipe and an outer portion. The inner and outer portions of the walking beam are pivotally interconnected above an axis extending through the centerline of the pipe. A pair of support members are pivotally connected to the outer portion of the walking beam on opposite sides of the pipe so that longitudinal loads to the pipe are reacted without effecting a bending moment in the pipe. In the preferred embodiment, a rigid strut and a yieldable snubber device comprise the support members.

Abstract: A solid state digital running time indicator is energized from the same power source supplying energy to a monitored event. A device for detecting when the power is on initiates a signal to timing circuitry for generating clock pulse signals and control timing signals. In response to an initial timing signal, a memory element reads the information from memory into a counter chain. The clock pulse signals are applied to the counter chain for counting up in predetermined increments of time from the number that is initially loaded into the counter chain from the memory element. Control circuitry writes the contents of the counter chain into the memory element after each predetermined increment of time. The total accumulated running time present in the counter chain is applied to drive and display circuitry for providing a visual indication of the running time of the event being monitored.

Abstract: In a thermal printer, a print element drive circuit has connected in series a CMOS (Complementary Metal Oxide Semiconductor) inverter gate driving a MOS (Metal Oxide Semiconductor) transistor which in turn drives a bipolar power transistor. The bipolar power transistor provides current pulses to a resistive element which is thermally activated in response to the pulses to cause the printing of characters upon thermal sensitive paper. Character decoding circuitry provides high impedence logic level inputs to the CMOS inverter and these inputs are converted by the printer driver circuitry into corresponding high current drive pulses.

Abstract: Two signals are correlated in a properly programmed digital computer to render a result reflecting the difference in time of arrival of the two signals at separate receiving stations from a common emitter station. Signals received at each of the receiver stations are converted into digital data and transmitted via a data link to a central correlation station. At the central correlation station, the individual digital signals are checked for magnitude and power content prior to conversion into the frequency domain by a fast Fourier transform. Previously stored calibration data from each of the receiver stations is combined with the frequency domain data to provide corrected information for correlation to determine the difference in time of arrival of signals from a common emitter station.

Abstract: A data collection and reduction system for a shock suppressor valve test system is provided. The test system includes a flow meter for generating a DC voltage signal corresponding to the velocity of fluid flowing through the flow meter and a recorder for recording and outputting an AC voltage signal corresponding to the velocity of fluid flowing through the flow meter. The data collection and reduction system includes circuitry interconnected to the flow meter for amplifying the DC voltage signal generated by the flow meter to produce an amplified DC voltage signal. Circuitry converts the amplified DC voltage signal to an AC voltage signal for application to the recorder for recordation of the velocity of the fluid flowing through the flow meter. Circuitry is further provided and interconnected to the recorder for amplifying the AC voltage signal output by the recorder.

Abstract: A prime focus multimode feed horn is used to illuminate a parabolic reflector such that the reflector-horn combination produces improved performance in the E-plane and H-plane of a principal aperture. A feed assembly which includes the multimode horn also has a hub assembly that is incorporated into the reflector with support structure, a boom, supporting interconnecting waveguides and the multimode dual frequency horn. Directly coupling the horn to the feed assembly is an orthomode generator connected to a receive waveguide and a transmit waveguide. The orthomode generator is assembled to a horn body waveguide that supports a horn aperture having a circular configured principal aperture surrounded by radially displaced circular rings forming concentric channels for modification of the E-plane receive pattern.

Abstract: A data collection and reduction system for a shock suppressor valve test system is provided. The test system includes a flow meter for generating a DC voltage signal corresponding to the velocity of fluid flowing through the flow meter and a recorder for recording and outputting an AC voltage signal corresponding to the velocity of fluid flowing through the flow meter. The data collection and reduction system includes circuitry interconnected to the flow meter for amplifying the DC voltage signal generated by the flow meter to produce an amplified DC voltage signal. Circuitry converts the amplified DC voltage signal to an AC voltage signal for application to the recorder for recordation of the velocity of the fluid flowing through the flow meter. Circuitry is further provided and interconnected to the recorder for amplifying the AC voltage signal output by the recorder.

Abstract: A prismatic plate is mounted with its flat face exposed to the sun on a reflector panel for use in a solar energy collection system. The plate includes a plurality of triangular prisms with parallel longitudinal axes shaped to provide total internal reflection of incident light rays. Each prism has a cross section forming a right-angled isosceles triangle with the two equal-length, rear faces of the prism oriented at 45 degrees relative to the front face of the plate. The base of each prism forms or is parallel to a front plate surface which receives incident solar light rays. The rays are transmitted through the plate cross section without refraction in the plane of the cross section to be reflected from the two rear faces and back out the front face toward a solar receiver. The prism material has an index of refraction equal to or greater than the square root of two so that there is total internal reflection from the prism faces.

Abstract: A bleed and fill system apparatus and method for in line servicing of shock suppressor reservoirs is provided. Vacuum and fluid canisters are mounted to a backpack that can be carried by maintenance personnel to the locations of shock suppressors. The apparatus includes a valve for attachment to the reservoir of the shock suppressor. Fluid lines interconnect the valve to the canisters. The valve is operable to independently connect either the vacuum canister or the fluid canister to the reservoir of the shock suppressor, such that when the vacuum canister is connected to the reservoir, air is bled from the fluid lines and connections to the shock suppressor and when the fluid canister is connected to the reservoir, fluid enters the reservoir to replace lost fluid. The system thereby permits in line servicing of shock suppressors without removal of the shock suppressor from its housing and mountings.

Abstract: A pressure-tight, rotary pipe joint couples rotating, high temperature gas transmission lines. Pressure seals of the pipe joint are maintained at a temperature lower than that of the transmitted gas by thermally insulating the seals from the gas and by pumping a fluid coolant through an annular cavity located adjacent the seals. As an alternate to fluid cooling, a metallic member, in which the pressure seals are disposed, is cooled by means of fins which transfer heat to the adjacent air.

Abstract: A thermal print head assembly for use in high speed printers of the dot matrix type wherein the thermal print element is forced against the printing paper and platen by means of bias springs. The thermal print head comprises a dot-generating thermal wafer which is rigidly mounted in a member supported by a frame and spring biased against the platen. The thermal print head as described may also include a biasing heater element and a plurality of thermal print heads combined together to form a thermal line printer.

Abstract: Bar codes imprinted or otherwise applied to an object are read and decoded by focusing light reflected from the code by means of an object lens to a light responsive transducer. Electrical signals produced by the transducer are correlated and converted from a trinary code format into a binary code format. The trinary code utilizes bars and half bars made up of segments in one or more of four quadrants to represent a decimal equivalent number. This trinary code is applied to a converter where logic converts the trinary signals into equivalent binary signals which are then translated from a serial format into a parallel format for further processing by conventional binary code processors.

Abstract: Terminal guidance of vehicles is accomplished by accurately determining true position and speed of the vehicle from terrain contour measurements and updating a dead reckoning navigation system with precision to permit navigation by following a programmed flight path. A narrow beam radar altitude sensor measures vehicle clearance altitudes and a reference altitude sensor measures the vehicle clearance above a reference level. These measurements are input to a digital processor for comparison to stored digital terrain contour reference data. Recursive data matching is performed in the digital processor by a nonlinear Kalman filtering technique to provide vehicle position and vehicle velocity correction signals to a navigation controller that generates steering commands to the vehicle control system. Three vehicle position and three vehicle velocity signals are generated and updated in the nonlinear Kalman filtering technique to give near real-time three dimensional position and velocity information.

Abstract: A selected message is displayed by an electromagnetic information display system having a matrix of display openings formed through a display board for receiving therein a plurality of solenoid coils. Magnetic display elements are disposed within each of the solenoid coils. The magnetic display elements have permanently magnetized poles located at opposite ends thereof and further have contrastingly colored surfaces associated with the magnetic poles. The solenoid coils are electrically interconnected for selectively inducing a magnetic field within any of the coils for aligning the display elements. A plurality of drivers are connected on an individual basis to one lead of all coils positioned within a column to output a ground or reference voltage as determined by the input of the driver.