Abstract: A biconical antenna having fully adjustable design parameters. The biconical antenna has a coaxial feed having outer and inner conductors. A lower support structure secures a lower cone to the outer conductor. An upper support structure secures an upper cone to the inner conductor. A dielectric window support is disposed between the lower and upper support structures. To make the antenna relatively lightweight, each cone may be made of sheet metal plates that are connected to the lower and upper cone support structures. A reservoir is formed within the upper cone. Dielectric material, such as oil, is disposed within the antenna. Air bubble escape holes are disposed in the upper support structure so that air bubbles that are formed at the coaxial feed can escape to the reservoir. The holes do not allow electromagnetic power leakage between the coaxial feed and the reservoir, and the position of the holes is such that the air bubbles rise from the coaxial feed into the reservoir.

Abstract: A wave-based detection system according to various aspects of the present invention analyzes signals in conjunction with a series of thresholds related to the anticipated input power of the incoming signals. The system implements a scheduled gain system to optimize the dynamic range according to the operating configuration of a transmitter and the characteristics of the receiver. The thresholds are correspondingly scaled using the scheduled gain. Because the thresholds are determined by an algorithm instead of a look up table, with the algorithm being based solely on the anticipated input power, the system uses significantly less memory and empirical data.

Abstract: A system and method that covertly provides in-flight target update data to a large number of missiles. The system and method covertly guides the missiles using a transponder located on a satellite that relays encoded target update data to receivers located on each of the missiles. The target update data is derived from intelligence data acquired by a remote sensing device. The target update data is typically transmitted to the missile launch site where it is encoded and transmitted to the transponder on the satellite. The encoding is preferably accomplished using direct sequence spread spectrum/code division multiple access (CDMA) encoding produced using unique seeds that are supplied to pseudo random code generators that uniquely encode the data to be transmitted to each missile. The receivers on each of the missiles have pseudo random code generators that are loaded with the unique seeds.

Abstract: A guidance system (30) for a missile comprising a sensor (20) mounted on the missile and having a fixed line-of-sight relative thereto. The body fixed sensor (20) provides a first signal representing frames of image data. A processor (40) identifies a target in the frames of image data and provides a second signal representative of the location of the centroid thereof. A conventional tracker (36) follows the target and provides a third signal representative of an aim point of the missile. A controller (44) then changes the velocity vector of the missile in response to the second and third signals. In a specific embodiment, the body fixed sensor (20) provides first and second frames of image data. The system (32, 34) subtracts the first and second frames of image data and ascertains a growth center of the target. The processor (40) compares the image growth center to the aim point and provides an error signal in response thereto.

Abstract: A microwave launcher includes a hollow microwave cavity in the shape of a plus sign, four coplanar exit ports in the arms of the microwave cavity, and a non-coplanar entry port at a central hub of the microwave cavity. A single magnetron is in communication with the entry port. There is a controllable, electrically activated microwave barrier at each of the exit ports. Each microwave barrier includes an electrical signal input whose operation controls the activation of the microwave barrier. A switching circuit has a voltage source for the electrical signal input of each of the microwave barriers. Microwave power output from the single microwave source is launched from the selected exit port by using the switching circuit to selectively block microwave passage through each of the nonselected exit ports, but to leave the selected exit port unblocked.

Abstract: Actuation apparatus for linearly engage and disengage pins respectively disposed along two predetermined (orthogonal) axes using a single actuator. The actuation apparatus comprises a housing and the actuator, which may comprise a DC torquer motor disposed in the housing. The actuator or motor has a threaded rotary shaft. A common plunger is coupled to the threaded rotary shaft that has an elevation ramp formed therein. Azimuth and elevation actuation pins are disposed along the predetermined axes within the housing that are moveable and extend outside the housing and retract into the housing when selectively actuated. Azimuth and elevation springs are disposed around the azimuth and elevation actuation pin. In a preferred embodiment, the pins are extendable into and removable from slots disposed in a moveable gimbal of a missile seeker, and locks an antenna disposed on the gimbal.

Abstract: A self adaptive limiter for use in aircraft control systems during approach and landing is disclosed. Estimated flight path angle is continuously computed during the glidepath tracking phase until a predetermined lock altitude above ground when a nominal flight path angle is latched. Nominal vertical speed is continuously computed below the lock altitude as a function of the latched nominal flight path angle and ground speed of the aircraft. A vertical speed limit function is generated as a function of the nominal vertical speed and radio altitude. During approach and landing a pitch limit is computed from the vertical speed limit, vertical speed, ground speed, and pitch. When a pitch command to the autopilot exceeds the pitch limit(i.e. commands excessive pitch down attitude), it is limited to the pitch limit thus preventing the aircraft from descending below a safe altitude.

Abstract: A system to alter the voltage supplied to the linear regulator of a pulsed transmitter in accordance with the temperature of the regulator, the minimum voltage required for a transmission and the specific aircraft installation requirements so as to reduce problems of heat dissipation in the regulator.

Abstract: A surface-protected composite article, such as a missile component, is prepared with a heat-sink substrate, a first composite layer of an pre-ceramic-matrix structural composite material, and a second composite layer of a reinforced silicone pre-ceramic material. The silicone material is co-curable with the organic matrix of the first composite layer. The silicone at the surface of the article is thereafter converted to a silica refractory by an appropriate treatment such as exposure to an oxygen-rich plasma or a high-surface temperature. The silica protects the surface of the composite material.

Abstract: A light-activated reflector having a plurality of coplanar arrays of parallel optical fibers that are each covered with a thin coating of a semiconductor material. Silicon, germanium, and indium antimonide, for example, along with other suitable materials, may be used as the coating of semiconductor material. The number and spacing of the coplanar arrays are determined by the shortest wavelength at which the reflector is to be operated. Electron-hole pairs are created in the coating of semiconductor material when it is illuminated by photons having energy greater than the band-gap energy of the semiconductor material. Light is injected into the optical fibers of a selected array. The injected light is absorbed and creates electron-hole pairs in the coating of semiconductor material, which modifies the permittivity of the coating. The absorbed light causes the coating to become reflective at millimeter wave frequencies.

Abstract: A radar system embeds information into the radar picture data for display on any display device. The radar receiver communicates weather data to a signal processor which generates a weather array. An I/O processor transmits data in the weather array to a display device via a picture bus. Alphanumeric data which is to be embedded into or combined with the weather array is stored in a message array. Font information for each alphanumeric character is stored in a font array. The message array and the font array are combined and translated into a text array which corresponds to the weather array. Prior to transmitting each radial of data to the display device, the I/O processor copies the appropriate radial data from the text array to the weather array thereby causing the desired alphanumeric characters to be displayed on the display device.

Abstract: A Traffic Alert and Collision Avoidance System(TCAS) antenna is mounted on a selected forward portion of an aircraft thereby extending the effective forward range of the TCAS. The antenna and ground plane are tilted relative to conventional TCAS antennas thereby aligning a peak of the antenna's radiation pattern along the aircraft's level line of flight. The resulting increased gain directed forward of the aircraft increases the forward range of the TCAS for both receiving and transmitting TCAS signals. The invention is also useful to extend the range of other aircraft systems including transponders. Alternate embodiments include tilting a conventional TCAS antenna mounted on a middle portion of the aircraft.

Abstract: An aircraft display combines speed error tapes and multiple speed reference bugs to produce a display which reduces pilot workload. The length of the speed error tape is indicative of the difference between a current aircraft speed and a reference speed. Multiple reference bugs are adjacent to the error tape and are indicative of the difference between the current aircraft speed and other selected reference speeds. The reference bugs move along the error tape thereby communicating the status of the current aircraft speed relative to the multiple reference speeds. The display reduces the need for the pilot to scan and analyze numerous instruments for the same information.

Abstract: An aircraft control system improves system flexibility, scalability, redundancy, and separation. The system uses a "virtual backplane" architecture which maximizes system flexibility and scalability and allows easy integration of new functions. The architecture comprises four major elements: processing modules; input and output modules (i.e. I/O modules); database modules; and an aircraft wide system network. Inter module communication occurs via the aircraft wide system network thereby eliminating the need for point to point communication and making modules independent of physical location or what modular units (MUs) they are in. Predetermined periodic and deterministic broadcast techniques improve the safety and communications efficiency of the system.

Abstract: An aircraft display system positions a synthetic runway which is properly aligned with a target runway even during crosswind approaches. The relative position of the target runway is computed in a manner which reduces the accumulated error associated with previous systems. The lateral deviation rate of the aircraft relative to the extended centerline of the target runway is computed from data provided by various aircraft navigation and sensor systems. A track error angle representative of the difference between the extended centerline of the runway and the ground track of the aircraft is computed from the lateral deviation rate and ground speed. Runway bearing relative to ground track is computed from the track error angle and lateral deviation angle. Compensating runway bearing relative to ground track with drift angle yields a runway bearing relative to aircraft heading which is useful for positioning a synthetic runway on a display.

Abstract: An aircraft display communicates three dimensional lateral information to a pilot of the aircraft. An extended course centerline symbol and lateral deviation marks indicate lateral deviation from a desired course along with approximate altitude and distance-to-go information to the pilot. The course centerline extends toward a vanishing point near the horizon line of the display. The centerline symbol swings laterally across the display responsive to changes in lateral deviation of the aircraft such that an intuitive perspective view is provided to the pilot. Lateral deviation marks provide precise lateral deviation information to the pilot. The display is adaptable to all phases of flight, but is particularly useful during the approach phase of flight. The preferred embodiment is on a head-up display for instrument flight conditions.

Abstract: An ambiguous dial indicator intuitively communicates the relative value of setpoints to an operator. The ambiguous dial indicator includes an ambiguous scale and a pointer or needle. The setpoints are represented by "bugs" which are adjacent to the ambiguous scale. The bugs are limited to a predetermined range about the pointer such that when a setpoint is outside of the predetermined range the associated bug is limited to an edge of the range. When several setpoints are outside of the predetermined range the several associated bugs saturate or park at the edges of the range. The invention is particularly useful in head-up displays and helmet mounted displays.

Abstract: A circuit measures the driving and circulating current in an H-bridge drive network directly and linearly. Voltage across two current sensing resistors are input to two precision half-wave rectifiers. The output of the rectifiers are input to a differential amplifier via a circuit of resistors. The output of the differential amplifier is a signal representative of the current in the H-bridge for both the driven periods and non-driven or freewheeling periods.

Abstract: A novel bias circuit provides precise base emitter voltage(V.sub.BE) which tracks the temperature coefficient of an RF transistor using low cost devices. The bias circuit includes a precision current source which injects current through a P-N junction device to derive a temperature compensating reference voltage thereacross. The P-N junction device is isolated from current fluctuations using a current isolation circuit coupled between the P-N junction device and the base of the RF transistor. The diode is thereby isolated from and unaffected by changes in the base current of the RF transistor. Multiple RF transistors are biased from the single P-N junction device by replicating only a trimming potentiometer and the current isolation circuitry for each additional RF transistor to be biased.

Abstract: An apparatus for providing lateral guidance through a plurality of waypoints utilizing curved path transitions. When the curved path transitions overlap due to a short leg there is a discontinuity in the desired path of the aircraft, causing the aircraft to experience excessive and oscillatory bank angles to maneuver through the turn. The invention adjusts the transition parameters so that there are no discontinuities in the flight path by computing a new turn radius, turn center, or turn center coordinates, in accordance with the course through the waypoints. The invention determines which flight plan legs are short and calculates the parameters so that the path will not violate air space boundaries and bank angles will be minimized. A circular path is generated tangential to course changes in the same or opposite direction, irrespective of the value of the flight plan leg length.