Abstract: Digital logic and a high resolution digital to analog converter are used to adequately digitize a magnetic signal that is subsequently processed by magnetic data processing algorithms. The high resolution digital to analog converter is directly incorporated in a feedback loop of a magnetometer sensor, an expensive precision analog to digital converter is replaced by a less expensive, lower power digital to analog converter. The circuit improvement provided by the present invention includes an analog low pass filter coupled to the sensor, a digital logic circuit coupled to the analog low pass filter for providing an output signal from the magnetometer and a feedback output signal, and the digital to analog converter coupled between the digital logic circuit and a feedback coil of the sensor for coupling the feedback output signal thereto.

Abstract: A transparent chuck is used to force a semiconductor wafer to take a prescribed shape. Any gap which is formed between the chuck and the wafer can be imaged through the transparent chuck. An interferometer is used to illuminate the gap with a narrow band illumination to create interference fringes in the gap. The fringes can be electronically imaged to create a digital input to a computer. Merit functions corresponding to the total volume of fringes in the gap or to the summation of nearest neighbor slopes of such fringes provide a measure of the thickness of such gap.

Abstract: In a launcher control system (12), a missile interface unit (29) for controlling a ground launched active radar guided missile (GLA) which is modular in construction. The missile interface unit (29) provides target position information and control signals for test and launch of the GLA, and power for activating the GLA, as well as determining the status of the GLA. It employs a plurality of cards (56-70), each card having a specific function and being interconnected by a backplane bus system (55) which also couples the cards (56-70) to other components of the launcher control system (12).

Abstract: A coplanar waveguide based microwave monolithic integrated circuit (MMIC) oscillator chip (14) having an active oscillator element (16) and a resonant capacitor (18) formed thereon is flip-chip mounted on a dielectric substrate (12). A resonant inductor (22) is formed on the substrate (12) and interconnected with the resonant capacitor (18) to form a high Q-factor resonant circuit for the oscillator (10). The resonant inductor (22) includes a shorted coplanar waveguide section (24) consisting of first and second ground strips (24b,24c), and a conductor strip (24a) extending between the first and second ground strips (24b,24c) in parallel relation thereto and being separated therefrom by first and second spaces (26a,26b) respectively. A shorting strip (24d) electrically interconnects adjacent ends of the conductor strip (24a) and first and second ground strips (24b,24c) respectively.

Abstract: An adaptive optics system and method for providing wavefront aberration compensation with both phase reversal and amplitude preservation. Two operational modes, namely, a transmission mode and a compensated imaging mode, are available. Two spatial light modulators, preferably liquid crystal light valves (LCLVs) are operatively connected in tandem. Each LCLV has an associated feedback loop. One LCLV acts upon the phase aberrations in an input aberrated beam and the other LCLV acts upon the amplitude information in the aberrated beam. Alternative embodiments are also disclosed.

Abstract: A drumlike canister onto which a filament is wound is rotatably mounted to an airborne vehicle, the axis of rotation being generally parallel to the vehicle longitudinal axis. At launch, as the filament unwinds and is payed out the canister is rotated to remove the twist from the filament produced on winding.

Abstract: A fiberoptic leader connected between a missile and a launch tube is paid out upon missile launch with a controlled degree of bend in the fiberoptic filament, and is furthermore protected from blast effects in the launch. The fiberoptic filament is stiffened within a leader comprised of a TEFLON sleeve insulating the fiberoptic filament. A protective sheathing of high tensile strength longitudinally wires are disposed about and encase the TEFLON sleeve, and in turn are encased within an outer sleeve. The stiffened leader is led along the longitudinal length of a C-shaped channel attached to the side of the missile. The channel is disposed upon a longitudinal portion of the missile. The stiffened leader is laid against and under one of the channel arms from the aft end of the missile, where the fiberoptic leader is fed out during launch, to a forward end of the missile and channel. The leader is then led across the width of the channel to the opposing arm of the C-shaped channel.

Abstract: A triangle wave generator (10) which is programmable, and which provides variable amplitude, frequency independent, triangle waves over a wide frequency bandwidth while employing a low voltage power source. The triangle wave generator (10) comprises a square wave input signal source (12) and a reference voltage signal source (14). A first amplifier (16) amplifies the square wave input signals and couples them by way of a transformer (34) to an integrator (36,40) which generates triangle wave output signals in response thereto. A second amplifier (18) connected to the triangle wave signal and to the transformer coupled square wave current source for the purpose of providing a bootstrap. A third amplifier (20) samples and compares the triangle wave output signals to the reference voltage signals and generates output error signals in response thereto.

Abstract: A staged missile which is reconfigured in-flight solely by changing vehicle dynamics enabling packaging of kinetric energy kill capability in severely constrained envelopes, thus retaining the use of existing tactical assets to counter advanced armored threats.

Abstract: A fiber optic canister includes a generally cylindrical bobbin and an optical fiber pack wound thereupon. The bobbin is formed at least in part from a material having orthotropic coefficient of expansion characteristics, arranged so that the coefficients of thermal expansion of the bobbin are matched to those of the overlying optical fiber pack. The optical fibers have a small longitudinal coefficient of thermal expansion and a larger transverse coefficient of thermal expansion. The orthotropic material of the bobbin is arranged so that the circumferential coefficient of thermal expansion of the bobbin is near zero, and the axial coefficient of thermal expansion is matched to that of the transverse coefficient of thermal expansion of the optical fiber pack. The bobbin therefore expands and contracts with changes in temperature at a rate approximating that of the overlying fiber pack.

Abstract: Optical systems with very long eye relief and large working distances (10) and (110) with four lenses (12), (14), (16), (18) and (20) and three lenses (112), (114) and (116), respectively, have lens surfaces shaped to focus upon an object such that a high resolution image is formed at infinity substantially over the entire field of view. High resolution and low distortion are substantially maintained independent of the user's eye location.

Abstract: A semi-active radar receiver for receiving a sequence of radar pulses and providing radar timing signals in response thereto. In a most general sense, the semi-active receiver of the present invention includes a receiver 10 for receiving a direct transmission of a series of pulses from a radar transmitter 2 and for providing a series of first signal pulses in response thereto. A range gate generator 42 is included for processing the series of first pulses to provide said radar timing signals. In a more specific embodiment, the receiver includes a filter 40 for processing said received pulses and deriving estimates of the timing of the receipt thereof. The estimates are then used by the range gate generator 42 to provide said radar timing signals.

Abstract: Apparatus and methods for providing nonuniformity compensation of staring infrared focal plane array imaging systems, or other video imaging ssytem, or the like. The invention comprises a processor which implements nonuniformity compensation of the detectors comprising the array. The processor generates compensation terms that are stored in an offset term memory and which are subsequently combined with the output signals from the array. The processing accomplished by the present invention normalizes all detector elements in the array such that they all appear to respond to infrared energy in an identical manner. The processor comprises a median filter which selectively implements cross (X) shaped and plus (+) shaped filters. An antimedian calculator computes the antimedian of the output of the median filter. This value comprises the difference between the central pixel of a respective filter and the median value of all pixels in the cross (X) or plus (+) shaped filter.

Abstract: A programmable counter or frequency divider includes the combination of a fixed modulus prescaler (110) and a programmable divider (120, 130, 140, 150, 160) in which the prescaler provides more than a single clock phase to the programmable divider and the programmable divider utilizes the multiple clock phases to allow operation in a true fractional-integer mode. The overall combination of the prescaler and programmable divider functions as a programmable divider for which the minimum increment in the overall divider modulus is less than the prescaler modulus, but the maximum clock frequency usable is the maximum clock frequency of the prescaler.

Abstract: A missile launching system with an open-ended cylindrical container (10) having a bore in which a slidable piston (20) is located between the missile (12) and a gas generator (14) adjacent the container aft end (16). The piston (20) area is substantially the same as the container bore at the aft end (16). An internal ring (42) forms a reduced area throat for gas exiting via the aft end of the container (10) with the ratio of the piston area to the throat area, A.sub.p /A.sub.t, being functionally related to the propellant physical characteristics.

Abstract: A deep nested filament winding includes a groove formed in a winding spool. The groove is disposed to provide an overall winding pitch about equal to the diameter of the filament multiplied by the square root of three (3).

Abstract: An open-ended cylindrical housing (50) with a slot (52) extending along one side contains within its bore first and second roller guides (54, 56) each having a longitudinal extending V-shaped groove (58) in an outer surface. The housing and included roller guides are located as a unit within an adhesive recovery tube (62) having a slot (66) along one side. In use, a fiber (18) with adhesive on its surface moves along the V-shaped grooves. Adjustment of the V-shaped groove aperture existing at the facing roller guide ends is accomplished by relative roller guide rotation.

Abstract: A method for determining the position and velocity of a target in inertial space including the steps of (a) tracking the target and providing three orthogonal velocity components in inertial space; (b) computing the scalar velocity V.sub.T of the target in an inertial reference frame by providing the square root of the sum of the squares of the orthogonal velocity components; and (c) computing the aspect angle .beta..sub.cue of the target relative to a line-of-sight to a platform as an inverse sinusoidal function of the ratio of one of said orthogonal components and V.sub.T, when such tracking data is available, and otherwise; (d) estimating actual target maneuver to develop a minimum uncertainty zone using an assumed worst case lateral target acceleration. Also disclosed are techniques for bounding the aspect angle and for providing global range and range rate estimates which account for uncertainties in the measurements of target and platform ranges and velocities.

Abstract: A moving optical fiber (10) is guided in its motion by an annular guide apparatus (40) which receives the optical fiber (10) within an inner bore (66) and stabilizes its transverse position as it moves longitudinally. The guide (40) has a plurality of gas jets extending into the inner bore (66) that create a cushion of gas to maintain the position of the optical fiber (10) in the center of the bore (66), without the need for any physical contact between the bore (66) and the optical fiber (10). The annular guide (40) is preferably formed from a housing (42) that defines a gas plenum (74) and a flow control plate (52) that fits to the housing (42) and has circumferentially spaced, radially extending gas flow passages (54) etched therein. A gas flow introduced into the plenum (74) from an external source is distributed to the gas flow passages (54) and thence to the inner bore (66) to prevent the optical fiber (10) from physically contacting the guide (40).

Abstract: A conventional tracker 14 is used to continually aim a sensor 12 at a flying object so that it is located in substantially the same spatial location in a plurality of image frames taken at different times. Thus, the object remains in about the same spatial position in each image frame while the background clutter generally changes. By processing two or more of the image frames it is possible to calculate a more precise aimpoint for the object than is generally provided by the track point.