Abstract: A detector array of a plurality of photodetector cells is provided which operates in two spectral bands by utilizing a polarity reversing multiplexer for directly reversing the polarity of different types of photodetector pairs. More particularly, long wave photoconductive quantum well detectors and near infrared photovoltaic detectors may be advantageously interconnected to supply the two detectors with different bias voltage levels by a polarity reversal function. This polarity reversal function exploits the low and high impedance characteristics of the detectors for enhancing the electrical interconnection. As a result, the system optimally changes the operation of the detector array from one photospectral band to another to take advantage of the electrical interconnection characteristics of both devices. As a further advantage, the circuitry used may be simplified for eliminating bias lines.

Abstract: A spacecraft includes a three-axis attitude control system. When velocity change thrusters are fired, their plumes impinge on a solar array, at angles which vary with the solar array position. This causes disturbance torques which vary with the solar array position. Disturbance torque information signals or torque bias signals which depend upon the solar array angle are summed with the torque demand signals which control the attitude control system during firing of the velocity change thrusters, to modify the attitude correction torques. The bias torque signals are generated by a Fourier processor based upon stored Fourier coefficients together with signals from a solar array angular position sensor.

Abstract: A continuously variable hydrostatic transmission includes an input shaft connected to drive a hydraulic pump unit, a grounded hydraulic motor unit, and an output shaft. A wedge-shaped swashplate is pivotally mounted to the output shaft in driving connection to receive output torque resulting from the exchange of pressurized hydraulic fluid between the pump and motor units through ports in the swashplate. A hydraulically actuated ratio controller is pivotally linked to the swashplate to selectively adjust the swashplate angle relative to the output shaft axis and thereby change transmission ratio.

Abstract: A speech signal has its characteristics extracted and encoded (16), transmitted over a limited-data-rate path (18) and is decoded (20) and synthesized (22) at the receiving end. The characteristics include line spectral frequencies (LSF), pitch and jitter. The LSF are extracted by autoregression, and splitvector quantized (SVQ) in a single frame, and, in parallel, in blocks of two, three and four frames. The SVQ codes have equal length and are evaluated for distortion in conjunction with a threshold. The threshold is varied in such a manner as tend to select for transmission those codewords which maintain a constant data rate into a transmit buffer. A single-bit jitter bit, and encoded pitch value, are product coded with the selected LSF codeword, and all are transmitted over the data path (18) to the receiver. The receiver decodes the characteristics, and controls a pitch generated (1226) in response to the pitch value and a random pitch jitter in response to the jitter bit.

Abstract: The final viewable color of each pixel to be displayed from video data signal output of a computer image generator, is found by: using input data signals setting display space coordinates of each vertex of each face polygon to be displayed, to generate a crossing location of each polygon edge along an edge segment of any of the array of display pixels; storing, and then processing, the edge segment crossing data signals for all polygons affecting that pixel, along with color data for each of the faces occupying any portion of that pixel, and for a plurality of different edge segments of a constellation of four adjacent pixels, to obtain pixel color intensity data for each corner of each displayable pixel; and mixing polygon color intensity data signals for all corners of a presently-processed pixel, to determine the final, observable color of that display pixel.

Abstract: A hydraulic pump (16) is driven by an induction motor (14) from a source of multiphase alternating current (10) of either fixed or variable frequency. The pressure is applied to a hydraulic load, which may vary, and change the pressure. A pressure sensor coupled to the pump produces pressure signals. The motor includes plural windings, typically three, associated with a number of poles. Each motor winding is driven by a different phase of controlled alternating current. A rectifier (46) coupled to the multiphase AC source generates direct current, which is filtered to minimize DC ripple voltage. A controllable multiphase inverter (54) is coupled to the rectifier and to the motor windings, for converting the direct voltage into multiphase alternating motor drive voltages of controllable amplitude and frequency.

Abstract: A propellant composition comprising an admixture of a first hydrogen rich material and a second metal material which is capable of reacting exothermically with the first material. The ratio of the first material to the second material is selected such that the exothermic reaction forms a solid phase and a gas phase which contains substantial amounts of hydrogen. Preferably, the first hydrogen rich material comprises a material capable of providing nitrogen upon decomposition thereof, and the second metal material comprises a material capable of reacting exothermically with the nitrogen generated by the decomposition of the first material such that the solid phase comprises a solid nitride of the second metal material.In a preferred embodiment, the first material comprises ammonium azide, and the second material comprises boron, titanium, titanium hydride, or mixture thereof.

Abstract: A method and apparatus for holding a line of sight in a scanning imaging system wherein there is continuous relative movement between the field of view of the system and an image plane. A descan mechanism temporarily holds a line of sight within a field of regard as a scanning mechanism such as a gimbal continuously moves imaging optics relative to the object space. The descan mechanism descans the image, the descan mechanism's relative movement being opposite to the direction of movement of the gimbal, so as to hold a line of sight for a time period and thereafter snap to a new field of view to thereafter descan the new line of sight for another time period. With the present invention a scanning system can be used with an imaging device requiring time integration for greater sensitivity, such as a staring electronic detector array or photographic film, without necessitating the physical scanning motion to be cyclically stopped and restarted.

Abstract: In a radar absorbing material, first or relatively resistive fibers are combined with second or relatively conductive fibers in a dielectric binder. Preferably, the first fibers are graphite filaments and the second fibers are metal coated graphite filaments. The appropriate selection of fibers results in a material having broadband or multi-frequency RF absorbing properties.

Abstract: A magnetic circulator is incorporated into a multi-chip module using a microwave high density interconnect (HDI) structure. A prepackaged circulator can be inserted into a ready-made high density interconnected multi-chip module; this prepackaged circulator may use a stripline design having a signal line with two ground planes above and below the signal line, or a microstrip transmission line design having one signal line and one ground plane below the signal line. Alternatively a circulator can be manufactured directly in a high density interconnected multi-chip module, with a stripline, or a microstrip transmission line design.

Abstract: A memory controller includes an input data path and an output data path. First circuitry generates signals to put the input data into at least one variably-dimensioned logical array of memory cells of a memory. Second circuitry generates signals to extract from the memory the contents of at least one variably-dimensioned logical array of memory cells. The memory may be double buffered such that data input to one of the portions may take place simultaneously as data output from the other of the portions. In a preferred embodiment, any combination of up to 254 total variable-dimensioned logical arrays of memory cells may be defined for input to and output from the memory. The memory controller may be viewed as supporting two simultaneous processes, an input "windowing" process for receiving windows of data and an output "windowing" process for simultaneously passing out windows of data.

Abstract: An initiator, for use in a gas generator, includes an enclosed volume in communication with apertures for introducing liquid propellant and pre-pressurization gas into a propellant ignition chamber, and an aperture for introducing combusted gasses into a gas generator. A mechanism for controlling when the gases are allowed to enter the gas generator, and a heater/electrode to initiate combustion of the liquid propellant, also communicate with the enclosed volume. The propellant and the pre-pressurization gas may be introduced together or through separate ports. The heater/electrode thermally decomposes and vaporizes the propellant causing pressurization of the ignition chamber until a critical value is reached and the propellant ignites and burns. The burning propellant increases the chamber pressure beyond a predetermined value thereby opening the controlling mechanism and allowing the combusted gases to be introduced into the gas generator combustion chamber.

Abstract: To resist mechanical forces tending to unseat a fluid valve applied to seal against a high fluid pressure, a fluid valve assembly is equipped with a valve block that, in response to the high fluid pressure, causes a locking member to be forcibly wedged into clamping engagement with the stem of a valve, thereby securing the valve in its closed, seated position. When the high fluid pressure is relieved, the valve stem is unclamped, and the valve can then be readily lifted to an open position.

Abstract: A continuous flow-rate gas generator fueled by liquid mono-propellant includes a propellant storage tank, a motor-driven pump (or other pressurization technique) to force the propellant into a combustion chamber having an enclosed volume, an injector to effectively break up the incoming liquid propellant into droplets that facilitate ignition and sustain combustion, an igniter to initiate the combustion process, a nozzle to expand the exhaust gases in order to optimize the pressure and temperature of the working fluid, and exhaust ducting to direct the flow and handle the further heat transfer requirements. If desired, the output may be varied through two mechanisms: either by including an exit gas valve used to vary the exit gas flow to match delivery needs; or by having a plurality of continuous gas generators connected in parallel to a manifold assembly and relying on the combination of mixed flow-rates to match a required gas output.

Abstract: A continuously variable hydrostatic transmission includes axially aligned input and output shafts journaled by a transmission housing and respectively coupled to a prime mover and a load. The input shaft drives a hydraulic pump unit, while a hydraulic motor unit is grounded to the transmission housing. A wedge-shaped swashplate is pivotally connected to the output shaft in operative position to accommodate pressurized hydraulic fluid exchanges between the pump and motor units. A controller is coupled to adjust the angular orientation of the swashplate relative to the output shaft axis and thus set the transmission ratio. A hydraulic circuit, connected into the hydraulic motor unit, is selectively operable to vent high and low fluid pressure sides of the swashplate to atmosphere, thus imposing a neutral transmission ratio condition regardless of the transmission ratio set by the controller.

Abstract: An apparatus for and method of ensuring proper transfer of data between two registers. A device driver utilizes a clock signal as an enable input before data is transferred from one register to another. This prevents a misregistration of data when delays in propagation of the clock signal exceed delays in propagation of data signals. In alternate embodiments, provision is made for bidirectional transfer by ANDing the clock signal with directional control signals to produce the enable signal. There is also a provision for implementing the concepts of the invention in connection with a shared bus interface, and in a bidirectional interface in such a manner as to ensure a lack of bus contention.

Abstract: A system for extracting a three-dimensional model of an object viewed in a selected scene, includes at least one camera for acquiring scene information, each from a different spatial-temporal aspect of the total scene. A digitizer converts the scene video and directional information to digital data, for at least temporary storage in a mass memory associated with a computer for data processing. An interactive display provides a means by which a human operator can view the stored scene information and select at least one scene object for which the computer will extract a 3D model, for subsequent use by a designated output device.

Abstract: A booster stage is positioned down-bore from the breech of a gun to contain a charge of liquid propellant that is ignited by the combustion gases of a detonated breech propellant charge trailing the projectile down the gun bore. The detonated liquid propellant increases the bore gas pressure and thus accelerates the projectile to a higher muzzle velocity.

Abstract: Apparatus for and method of increasing the effective integration time, and, hence, reducing the noise bandwidth of a photodetector. The current output of the photodetector is converted to a voltage signal in a low pass filter. The low pass filter is preferably implemented as a switched capacitor filter.

Abstract: A sigma-delta analog-to-digital converter (10) provides high loop gain for suppression of noise components by use of a regenerative feedback loop or resonator (50), which produces a comb resonance response 212), embedded in the main degenerative feedback loop (48). The main loop includes an ADC (32) which samples at a clock frequency, which in turn defines a Nyquist frequency. The main loop also includes a DAC (38) which has a transfer function (42), which is equalized by a filter (44). The resonator (50) includes a low-pass filter (52) which matches the equalized main loop transfer function, a DC block (56), and a null filter (54) which nulls the resonator gain at the comb peak which lies above the Nyquist frequency. The open-loop transfer function of the regenerative loop (50) is set to unity gain and 0.degree..+-.N 360.degree. phase at the frequency of the analog input signal. A multipole embodiment (510) has multiple regenerative loops (55o) which produce multipole noise rejection (642).