Abstract: A preemptive processor for a tactical collision avoidance system (TCAS) selects mode S squitter messages from closer airplanes on a priority basis. The receiver has a higher sensitivity level to receive squitter messages at greater ranges. The high-level squitter messages preempt the lower-level squitter messages. The preemptive processor can be implemented as part of a application-specific integrated circuit (ASIC).

Abstract: A dielectric heater for subject material by connecting an RF source, modulated to produce a spread-spectrum signal to a radio frequency applicator for the subject material, without requiring an impedance matching network. The carrier frequency of the RF source may be selected to match the impedance of the subject material and applicator network.

Abstract: A TCAS receiver, including a relative bearing measurement radio receiving apparatus for use with an antenna array having four antennas where each antenna has associated with it, its own receiver capable of demodulating both I and Q components of transmissions from an intruding aircraft.

Abstract: A system and method of detecting and correcting for cycle slip in a GPS attitude determination system is presented. The method employs several techniques for detecting and correcting for faults in high integrity carrier phase-related applications. A delta single difference is used as a primary measurement residual in detecting cycle slip. The delta single difference represents the difference in phase of a carrier signal of a GPS satellite at two receiving antennas over two points in time. This delta single difference is compared to a detection failure threshold computed based on certain high integrity needs. Satellites showing a failure are excluded. In addition, satellites that fail a detectability test, indicating the inability to detect a fault, are pre-excluded from attitude solution computation.

Abstract: An aircraft ice detector system includes a radar system. The radar system provides a radar signal to a surface of the aircraft and determines whether ice is present based upon a reflected radar signal. The system can determine the type and the quantity of ice present based upon the reflected radar signal. The system can be mounted within a wing or on an external surface of the aircraft. The radar signal is preferably a low power signal.

Abstract: A navigation system for spinning projectiles using a magnetic spin sensor to measure the projectile roll angle by sensing changes in magnetic flux as the projectile rotates through the earth's magnetic field is disclosed. The magnetic spin sensor measurements are used to despin a body reference frame such that position, velocity, and attitude of the projectile can be determined by using a strapdown inertial navigation system (INS) algorithm. More particularly, a multisensor concept is used to measure pitch and yaw angular rates, by measuring Coriolis acceleration along the roll axis and demodulating the pitch and yaw rates therefrom.

Abstract: An integrated vertical situation display (IVSD) for an aircraft, and method of displaying vertical situation information, are disclosed herein. The IVSD includes an electronic display for displaying the vertical situation of the aircraft, input interfaces for receiving vertical profile information signals, and a processing circuit for reading the information signals and generating display signals applied to the display therefrom. The display has a vertical profile view area to display the vertical situation in front of, above, and below the aircraft. The information sources may include a flight management system, traffic alert and collision avoidance system (TCAS) and a ground proximity warning system. Vertical situations are displayed by visual indicia representing, for example, aircraft position, path angle, flight path, waypoints, TCAS targets, altitude preselect, decision height, runway, ground contour, and vertical speed.

Abstract: A multi-mode, multi-band, multi-user radio system architecture includes four channels of exciter circuits and receiver circuits coupled to a digital signal processing array. Each of the exciter and receiver circuits includes three separate signal paths for three separate frequency ranges of analog signals. Each path includes an analog-to-digital converter or a digital-to-analog converter for converting both modulated analog signals to modulated digital signals and modulated digital signals to modulated analog signals. The digital signal processing array performs modulation and demodulation functions for the radio system.

Abstract: A programmable high frequency (HF) bandpass filter is disclosed. The programmable filter has a tunable bandwidth and center frequency over a large range of the radio frequency (RF) and intermediate frequency (IF) spectrum. The programmable filter incorporates micro-electro-mechanical switches (MEMS), Acoustic Charge Transport (ACT) devices, or a combination thereof, to provide tunability of the bandpass filter response characteristics.

Abstract: Disclosed is an avionics display device for use in the cockpit of an aircraft. The display device includes a liquid crystal display adapted for using a source of light to display information to a viewer and a backlight adapted to controllably provide a portion of the source of light for use by the liquid crystal display in displaying the information. A polymer dispersed liquid crystal (PDLC) device is positioned between the liquid crystal display and the backlight. An ambient light sensor adapted to sense a level of ambient light in the cockpit of the aircraft provides a sensor output indicative of the sensed ambient light level. Luminance control circuitry coupled to the ambient light sensor, to the backlight and to the PDLC device, receives the sensor output and generates as a function of the sensed ambient light level control signals for controlling the intensity of the light provided by the backlight and the transmissivity of the PDLC device.

Abstract: A tool for laying out a pattern of a measured size and orienting the pattern with respect to an exterior point of reference is disclosed. A cord having a plurality of anchoring points spaced along its length is arrayed to form the pattern. A direction finding device orients the pattern formed by the cord to a point of reference exterior to the pattern. Anchoring devices anchor each anchoring point of the cord to a surface so that the cord is held to the surface in the shape of the pattern. The cord is attached to a spool which stows the cord, anchoring devices, and direction finding device when not deployed.

Abstract: A system for monitoring guiding and controlling an unmanned, unteathered flight vehicle, generally assumed to be moving through the earth's atmosphere at a high rate of speed. The system is comprised of on-board positional receiver and processing means coupled to a transceiver capable of combining such positional information with additional data relative to the health and status of the flight vehicle and transmitting the same to a ground station of compatible and simplified design. A preferred positional determination means is to utilize a form for GPS signal thereby affording one the opportunity to include appropriate processing software or additional componentry if necessary for base station purposes and thereby provide a relatively inexpensive system having a low probability of detection for intercept that simultaneously yields vastly improved operating performance characteristics over the mere translation of received GPS signals to down-link or to remote stations as known in the prior art.

Abstract: A fluorescent lamp controller for fluorescent lamps, the controller being responsive to the instantaneous power applied to the filaments and further generating a computed temperature signal to drive a filament as a function of the thermal characteristics of time versus temperature of the filament where the controller further controls application of arc power to the fluorescent lamp based upon the computed temperature signal.

Abstract: A remote menuing system uses a control knob to select menu items on a display screen. The menu items may be selected by depressing a switch, the switch being integrated with the control knob. Once the menu item has been selected, an operator may modify the value of the selected item by rotating the control knob. When a desired value is displayed, the item may be set by again depressing the switch integrated with the control knob. The use of an integrated control knob and switch, provides ease of use of a menu system while allowing the integrated knob to be located away from the display screen.

Abstract: Aircraft tail strike protection is provided by displaying to a pilot tail strike warning symbols during takeoff and approach to landing. In a takeoff scenario, a pitch margin indicator symbol referenced to a boresight symbol provides a pilot with anticipatory information and an awareness of the pitch attitude margin before a tail strike incident. In an approach to landing scenario, a TAILSTRIKE warning annunciation is referenced to a flight path symbol and alerts the pilot of an impending tail strike incident. The symbols displayed during either scenario center on the pilot area of focus for each task. They give the pilot an awareness of an impending tail strike incident and necessary reaction time to avoid it.

Abstract: A multi-color optical display system is designed with a bi-fold prism assembly in a relay lens that, together with a multi-spectrally reflecting optical combiner, longitudinally corrects a multi-colored image composed of two or more discrete wavelengths of light. The prism assembly for a preferred two-color image typically includes three light reflecting surfaces, the first of which may be flat or curved and coated with a spectrally reflective coating of a given wavelength; the second of which is flat or curved, coated with a spectrally reflective coating of a given second wavelength, and spaced a small amount from the first surface; and the third of which is flat, separated from the first two by a large distance and angle, and uncoated. The coatings are chosen to each reflect a specific wavelength range of colored light used in the display system and to transmit all other wavelengths.

Abstract: Aircraft display symbology provides quantitative deceleration information in relation to a pilot familiar reference on a HUD system combiner. The symbology displayed includes a deceleration scale composed of a series of marks that provide a known reference for the display of deceleration information. The number of marks on the scale and the positioning and labeling of the marks can be tailored for a particular aircraft type. In a preferred embodiment, the deceleration scale is displayed along and proximal to the vertical path traveled by an aircraft acceleration symbol, which indicates the actual longitudinal acceleration or deceleration of the aircraft. The offset distance of the aircraft acceleration symbol below an aircraft reference or "boresight" symbol shows the actual (inertial) deceleration during landing rollout and rejected takeoff.

Abstract: A programmable prescaler for scaling an input frequency into a desired output frequency including an input divider having an input connected to the input frequency and a divided output, a first counter, having an input connected to the divided output of the input divider and a terminal count output; and a second counter coupled to the terminal count output of the first counter having a scaled-frequency output. The second counter may be a divide by two counter, and may be coupled to the terminal count output of the first counter via the input divider. The input divider further may further include a plurality of divider stages, the input frequency and the terminal count output being cascaded through the plurality of divider stages, and wherein the second counter is coupled to the terminal count output of the first counter via the plurality of divider stages of the input divider.

Abstract: An antenna for utilization in a fuse of an artillery shell or the like. The antenna includes a dielectric disk having upper and lower surfaces, a radiator disposed on the upper surface of the dielectric disk, a ground plane disposed on the lower surface of said dielectric disk, and a plurality of spaced apart apertures radially disposed through the dielectric disk for coupling the radiator to the ground plane.

Abstract: A method for increasing the accuracy of ranging measurements between data link systems is described. The method, actively aided ranging, increases ranging measurement accuracy by decreasing the dependence of the measurement on the relative clock bias between data links. The method is immune from error due to time bias between a position interrogator and a responder.