Abstract: Range discontinuities (44) in an imaged scene are located with superior accuracy by using a pair of stereoscopically related images (10, 12) of the scene to sense edges in the scene, and to determine the range of correlatable image pixels; segmenting the scene into regions (36) of similar intensity; assigning to each region (36) a range based upon the range of any correlatable pixels in it; and locating the boundary (44) between adjacent regions of substantially dissimilar range.

Abstract: Coolant passages (14) of non-machinable size and shape are formed in a ceramic body (10) by individually forming sections (16) of the body (10), embedding graphite (20) therein during preforming, assembling the sections (16) into a complete preform (11), integrating the preform (24) by densifying it in an inert atmosphere under heat and pressure, and then heating the densified preform (10) in air to vaporize the graphite (19,20). In another aspect of the invention, a ceramic body (32) is formed from a three-dimensional, filled-in weave of silica fibers (30) in which the fibers (34) extending in one of the three dimensions are graphite and are subsequently vaporized.

Abstract: A dual mode microstrip resonator (1) usable in the design of microwave communication filters. The substantially square resonator (1) provides paths for a pair of orthogonal signals which are coupled together using a perturbation located in at least one corner of the resonator (1). The perturbation can be introduced by notching (3) the resonator (1) or by adding a metallic or dielectric stub (5) to the resonator (1).

Abstract: An interface module for coupling a VMEbus channel to a Universal Common Data Point channel and exchanging data signals in either direction. The module responds to protocol handshake signals from the originating channel, accepts a multi-word message-block, and provides handshake signals to notify the destination channel of message to be delivered. The module then transfers the message-block to the destination channel.

Abstract: A method for East/West stationkeeping of a geostationary satellite maintains the osculating value of longitude from exceeding a specified deadband for a specified drift period between maneuvers. In the planning, the mean longitude, the mean drift rate and the mean eccentricity vector are calculated and then maneuvers are executed to maintain the values below a magnitude such that the osculating longitude will be within the specified deadband over a specified drift period. The target conditions are achieved through a plurality of maneuvers which initiate a period of free drift which lasts for a specified number of days. During the free-drift period, longitude remains within its deadband, and no additional maneuvers are needed or are performed. The method has the advantage that it can take into account limitations on thruster on-time by allowing for a generalized number of stationkeeping maneuvers.

Abstract: A lock detector circuit (60) for demodulators of UQPSK signals I and Q has signal processing circuits for forming the signals:A=6I.sup.2 Q.sup.2 -I.sup.4 -Q.sup.4 ;B=4(I.sup.2 -Q.sup.2).A switch (19) is provided for coupling either signal A or signal B to the output (20) of the detector circuit, depending on the value of the signal ratio Q/I. In an alternative embodiment, a summing circuit adds signal A and signal B, and directs the sum to the detector output (20). The resulting output signal is constant under lock conditions, and oscillates when the demodulator is unlocked. This output signal is directed through a comparator (49) to the sweep circuit (43) controlling demodulator VCO (42), and causes the demodulator to remain in the locked condition. The lock detector circuit is effective for any value of Q/I, and utilizes only three analog multiplier circuits.

Abstract: The EHF omnidirectional antenna system (10) includes a shaped lens (12) that is illuminated by a corrugated horn (14). The lens is disposed in the far-field of the horn and has two shaped surfaces (20 and 30) which together disperse the beam from the horn, such that a nearly uniform coverage over hemispherical coverage area is achieved at a frequency of approximately 44 GHz. The method of making the lens utilizes a surface shaping analysis to develop the shaped surfaces of the lens. A surface matching layer (44) is applied to all surfaces of the lens to reduce surface reflection.

Abstract: A laser targeting system comprises an airborne reconnaissance platform (1) disposed to conduct surveillance of enemy air, ground, and/or sea targets (5). The surveillance means (11) can be some combination of FLIR, laser, or radar devices. Platform (1) may be manned or may be a remote pilotless vehicle commanded by a ground control station (9). Several friendly units (2) are capable of firing weapons at the enemy targets (5). The friendly units (2) desire real-time targeting information, such as video images, range, and coordinates. The friendly units (2) typically desire information for only certain types of targets (5) or for those within proximate geographical areas. These selective requests are sent via a laser uplink (28) to platform (1), which determines the direction from which the request came by a direction determining means (17), and selectively processes the request by means of a decoder/controller (16).

Abstract: A multiple beam array antenna that is designed with an aperture shape which conforms to the particular coverage area to which the antenna is directed. The antenna consists of individual horn antennas (20) that are nested together to form the array (14). The outer walls (50) of the peripherally disposed horn antennas (40) are individually shaped such that the combined shape of the outer walls (50) of the peripherally disposed horn antennas (40) determine the perimeter shape of the aperture (12) of the horn array (14). Where the desired coverage area is circular, elliptical or irregularly shaped, the shape of the perimeter of the aperture (12) of the horn array (14) is similarly circular, elliptical or irregularly shaped, respectively.

Abstract: The electronic simplicity of a rotating-telescope target acquisition device and the noise immunity and wide field of view of a non-rotating array device are combined in an assembly (10) using a rotating refractory telescope (21) on a gimbaled platform (28) and a combination reticle (38) and infrared detector array (34) on the same platform (28). The detector array (34) is segmented (50) to detect the direction in which a target is substantially off the telescope's optical axis (32), and the detector array (34) is also shielded (35) against any radiation coming from outside the optical path of the telescope (21). The reticle (38) also serves as the electrical connection (42,62) between the detector segments (40,50) and the contact pads (44,64) on the detector plate (36) and as a non-emitting shield against any external radiation.

Abstract: Friction in a traction drive assembly having counter-rotating races interconnected by drive balls captured by a stationary retainer is substantially reduced, and the life of the assembly is substantially extended, by interposing rolling interface elements between the drive balls and the retainer. The interface elements may take the form of balls, pins or wheels, and separate lubricating means for them may be provided.

Abstract: A coated article comprising an article to be encapsulated within an encapsulant and subjected to hot isostatic pressing, and a coating. The coating is composed of boron nitride and carbon in an amount effective to reduce interaction between the article and the encapsulant during the hot isostatic pressing. The carbon is present up to about 30% by weight of the total boron nitride and carbon in said coating.

Abstract: A circuit for selecting and combining power signals of a pair of parallel amplifiers (3,4) using phase shifters (5,6) having fixed phase. Either amplifier (3,4) may be selected to produce a power signal of power P at the circuit output (9), where P is the power at the output (11,12) of each amplifier (3,4). Alternatively, power from the two amplifiers (3,4) may be combined to produce a signal of power 2P at the circuit output (9). By using a passive circuit to achieve the selection and combination, the use of heavier and less reliable relay switches is avoided.

Abstract: A tool (b 10) for handling fiber optic connectors (46) in narrow spaces features a thin collet tube (34) tapered at its end (42), and a pintle (32) axially movable within the collet tube (34) with a generally axially oriented grasping surface (52) at its end (40). The taper of the tube (34) forces the grasping surface (52) toward the inside wall (48) of the collet tube (34) when the pintle (32) is extended through the tube (34). The tang (44) of a fiber optic connected (46) is grasped between the grasping surface (52) and the collet tube wall (48). The tip (56) of the collet tube (34) is inclined to prevent damage to the optical fiber (54). By slotting the collet tube tip (b 60), transversely extending workpieces (62) may also be grasped.

Abstract: The invention is directed to a solid, pyrotechnic composition as a base-bleed composition for reducing the base-drag of non-self-propelled projectiles. The composition comprises a oxygenated hydrocarbon component and an oxidizing agent component.

Abstract: The efficiency of a metal silicide infrared (10) in greatly enhanced by depositing on the substrate (14) a stack (30) of alternating metal silicide (12,24) and silicon layers (22). The metal silicide layers (12,24) are connected to each other and to a contact pad (20) in the substrate (14) by a metal silicide deposit (32) on one side of the stack (30) and the silicon layers (22) are connected to each other and to the substrate (14) by a silicon deposit (34) on another side of the stack (30). The stacking of layers is made possible by depositing the silicon layers (22) at a rate of 1 .ANG./sec or less in a vacuum of 10.sup.-9 torr or better at a temperature of about 250.degree. C.

Abstract: A cartridge case for a telescoped ammunition round has a generally tubular case wall and an axially extending elongate score line in said wall to provide pressure relief during firing of the round. The elongate score line has a radial depth less than the radial thickness of the wall.

Abstract: An encoder for selected linear error correcting codes, such as a BCH code, uses relatively low-speed circuitry to generate parities for correcting the code. A parity matrix derived from the BCH generator matrix is provided as data to a generator vector whereby the generator vector is used as a logical shift function generator. When the logical shift function is applied to the rows of the parity matrix, columns of parity are shifted into an EXCLUSIVE-OR tree to produce the parity bit of the column. The parity bit of the column is then injected into a data stream forming the encoded symbol for transmission, attaching the parity word following the data word. The apparatus may be constructed making maximum use of the standard, commerically available, relatively low-cost integrated circuits, but it is nevertheless capable of operating at speeds in excess 1 GBPS.

Abstract: A stationary, lightweight, easily transportatable antenna capable of full duplex operation, i.e., portions of the antenna can transmit and receive simultaneously in the same frequency band. The antenna has a near omnidirectional pattern in the azimuth plane for both transmit and receive. The receive portion (2) consists of four antenna elements (20), each having a beamwidth in the azimuth plane slightly greater than 90.degree.. The receive antennas (20) are arranged symmetrically about a midpoint (93) that lies in the azimuth plane. The beams of the four receive antennas (20) face outwardly away from the midpoint (93) and thereby cover the full azimuth plane. The transmit portion (1) of the antenna is a colinear set of dipole elements (12) arranged within a cylinder (11) that is orthogonal to the azimuth plane and centered on said midpoint (93).

Abstract: Edge definition in FLIR images is improved by assigning to each pixel (X) the average intensity value of that 3.times.3 pixel sub-matrix (30a-30i) containing the pixel (X) which exhibits the smallest edge value. Apparatus for obtaining that intensity value in real time is disclosed. This process can be iteratively repeated on the same image, with each iteration creating more enhanced edges and greater area smoothing between edges.