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: Slow cook-off protection for rocket motors is achieved through the use of a slow cook-off trigger mechanism in which a mechanical response is thermally initiated. A metallic housing contains and is thermally coupled to a bimetallic snap action disc spring. A firing pin is connected to the disc spring and telescopically guided by the housing toward an expolosive booster charge. The booster charge is coupled in a conventional manner to a linear shaped charge. The linear shaped charge is disposed adjacent to the rocket motor case in order to cut a stress riser in the casing when activated. The circular bimetallic spring is designed to snap between a first and second configuration to thereby drive the firing pin into the explosive booster charge at a predetermined temperature below the expected ignition temperature of the rocket propellant. After the trigger is activated and the linear chaped charge cuts a stress riser in a rocket casing, continued temperature rise results ignition of the rocket propellant.

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: 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.

Abstract: An optical fiber is joined, preferably with an ultraviolet curable adhesive, to a strip of a flexible support material such as a plastic tape to form an optical fiber assembly. The assembly is wound onto a bobbin to form an optical fiber canister, which is then paid out upon demand. The optical fiber assembly requires little or no adhesive to hold it in place on the bobbin, as the support material of each turn aids in holding the adjacent turns in place, with the result that the bend radius during payout is increased.

Abstract: An optical fiber is proof tested by bending it relative to the fiber axis by a preselected amount, in all directions and at all locations along the length of the fiber. In one approach, the optical fiber is wrapped around a cylindrical mandrel in a helical pattern and drawn over the mandrel through its entire length. With the preferred helical angle of about 45 degrees, two wraps of the optical fiber around the mandrel ensure that all of the fiber will be bent in all directions. If a flaw exists in the optical fiber that would cause failure at any amount of bending below that of the preselected amount, this proof test will cause the fiber to fail so that the weak point may be eliminated.

Abstract: An improved direct, two-way data link is disclosed. The improved data link is used with an electronically steerable active array 10. The uplink comprises a transmitter radar means 60 mounted in a first vehicle for providing a first data signal and transmitting this first data signal as a first radar data signal to a second vehicle and radar receiver means 130 mounted in this second vehicle for extracting the first data signal from the first radar data signal. The downlink comprises transmitter radar means 150 mounted in the second vehicle for providing a second data signal and transmitting this second data signal as a second radar data signal and radar receiver means 80 mounted in the first vehicle for extracting the second data signal from the second radar data signal.

Abstract: Two optical fibers are spliced together to form a single spliced optical fiber. The spliced region is uncontaminated by impurities, and has substantially no loss of optical transmission or mechanical strength as compared to the other regions of the fibers. Splicing is accomplished by removal of the buffer coating, if any, cleaving of the fibers to be spliced to form facing splicing surfaces, careful precleaning of the cleaved fibers in the region adjacent the splicing surfaces, aligning the fibers using optical transmission as the alignment criterion, fusing the fibers together by preheating the region to be spliced, fusing the region, postannealing the spliced region, carefully postcleaning the spliced region, and recoating the spliced region with a UV curable polymer buffer material, if desired. The heating of the fibers to accomplish the fusion is desirably accomplished by a laser such as a carbon dioxide laser.

Abstract: A compound angle limiting device is disclosed herein. The invention provides for control of the angular excursion of a pivotal mass within first and second angles about first and second axes without the necessity for external stops. The invention includes a first coupling mechanism for sensing movement of the mass about the first axis, a second coupling mechanism for sensing movement of the mass about the second axis; a first cam coupled to the mass via the first coupling mechanism and movable in response thereto; and a second cam coupled to the mass via the second coupling mechanism and movable in response thereto. The first and second cams are mounted for physical contact at at least one point to limit the compound angular excursion of the mass via the first and second coupling mechanisms.

Abstract: A method and apparatus for payout testing of an optical fiber. The invention involves the attachment of a pod to a high speed aircraft with a parachute released during flight to initiate payout. The apparatus of the invention includes a bobbin mounted on a craft for retaining a coil of optical fiber and a parachute for using the air or fluid flow past the craft when the craft is in motion to pull the fiber from the coil. In a specific embodiment, the invention includes an electrooptical circuit for sending and receiving an optical signal along the fiber. Further, more specific, embodiments contemplate the use of load cells on the craft and parachute ends of the fiber to measure tension. This information is then transmitted to a receiver for analysis and/or storage. Other specific embodiments include a brake for inhibiting the payout of fiber during aborted test runs and a turns counter for providing a measure of the rate and amount of fiber payout.

Abstract: A plurality of pursuers or defensive missiles which are self-guided and self-propelled individually assign themselves to one of a plurality of targets or incoming offensive missiles in such a manner that the probability is substantially increased that more targets will be selected by at least one pursuer and that fewer targets will be selected by more than one pursuer.

Abstract: An information bearing signal (the object signal) for use in radar or radar-like circuitry is generated in a digital circuit and then converted through a bandpass matching filter into a corresponding analog signal. The object signal is then first combined in a NAND gate with a blanking control signal. In one embodiment, the selectively blanked object signal is frequency doubled by combining the blanked object signal and its quarter wave length shifted version in an EXCLUSIVE-OR gate. Thereafter, the frequency doubled version of the blanked object signal is combined in a second EXCLUSIVE-OR gate with a biphase modulation control signal which selectively inverts or noninverts the frequency doubled object signal. The output of the biphase modulated frequency doubled signal is then gated through a blanking NAND gate and coupled to the bandpass matching filter.

Abstract: Two contiguous half-height waveguides (12, 14) having a common broad wall (16) are provided with a pair of closely spaced equal length slots (20) and a single unbalanced-fed half-wave dipole (24) located parallel to and between the slots, with feed line coupled to the waveguide walls between the slots and provides for both longitudinal and transverse polarization. When the waveguides are excited in phase (even mode), the slots radiate similar to a single shunt slot with a longitudinal polarization. When the waveguides ae excited out of phase (an odd mode), the dipole is the primary radiator, radiating energy in a transverse polarization.

Abstract: A pulse code modulation decommutator interface system includes a standard computer interface, a standard decommutator interface, control logic and memory. Control signals from the computer selectively control the data transfer from the memory to the computer. The memory can selectively be used to store information therein that is thus accessible by the computer to validate the decommutator data transferred to the computer.

Abstract: The corporate feed network employs light emitting opto-electronic components, such as laser diodes (12), connected together in a string (14) for distributing RF, microwave, MMW, digital signals, and pulse modulated light. Each diode provides two ports or facets which are coupled to optical fibers (16, 18) to connect to an active phased array antenna, for example. The diodes are selected in number and impedance to provide a good wideband impedance match to the RF/microwave/MMW/digital driving source. Multiple series strings of diodes may be employed, connected in parallel for larger corporate feed structures.

Abstract: A stereomicroscopic inspection system having low eyestrain features is disclosed. The system (10) includes an objective lens assembly (12) for forming an image of a viewed object (22). A prism mechanism (14) is positioned adjacent to the objective lens assembly (12) for orienting the image along a heads-up axis. A telephoto objective assembly (16) is positioned adjacent to the prism mechanism (16) for focusing the image transmitted through the prism mechanism (14). A reticle (18) is positioned adjacent to the telephoto objective assembly, and the image is focused (16) onto the reticle (18). An assembly (20) is positioned adjacent to the reticle (18) for enabling heads-up viewing of the object by the viewer, (22) said system projecting a virtual image at a predetermined distance from the viewer. This distance may be substantially equal to the eye's natural focusing distance to minimize eyestrain.