Abstract: An airborne weather radar system that detects potentially hazardous weather conditions associated with storms and includes a radar display featuring visual indications of these conditions. The radar display includes a vertical situation display having iconal representations and symbolic icons indicative hazardous weather conditions and aviation hazards along the aircraft's flight path not otherwise immediately apparent or shown on standard weather radar displays. The system includes processes for detecting and predicting hazardous weather conditions such as overshooting thunderstorm tops and vaulted thunderstorm energy and serious hazards such as turbulence and hail.

Abstract: A radio frequency (RF) amplifier system includes an RF power amplifier having an input and an output, and a typical gain of 1000 or more between the input and the output. An adaptive feedback channel is coupled between the input and the output of the RF power amplifier. The adaptive feedback channel receives as inputs audio signals for modulation of the input of the RF power amplifier, a frequency command word indicative of a desired frequency and phase of the RF amplifier system, and a control word indicative of a desired power level of the output of the RF power amplifier and of a mode of operation of the RF amplifier system. In response to the inputs, the adaptive feedback channel provides as an output a degenerative feedback signal to the input of the RF power amplifier.

Abstract: A multiband waveguide reflector antenna feed comprises waveguide feeds in a concentric architecture. A waveguide feed is located in the center and coaxial waveguide feeds are disposed around the center feed. The waveguide feeds may be all-metallic with the center feed operating in a TE11 mode and the coaxial feeds operating in a coaxial TE11 mode. The waveguide feeds may have electromagnetic band gap (EBG) surfaces on waveguide surfaces. The center waveguide feed may have an EBG outer conductor surface and operate in a circular waveguide TEM mode. The coaxial waveguide feeds may have EBG inner and outer conductors and operate in a circular waveguide TEM mode. The coaxial feeds may have EBG inner conductors and near perfect electrical conductor (PEC) outer conductors and operate in a circular waveguide-like TE11 mode or may comprise EBG outer conductors and PEC inner conductors and operate in a quasi-TEM waveguide mode.

Abstract: A method of increasing situational awareness of terrain is disclosed. A representation of a terrain feature is generated from a source of stored data. A distance from a reference point to the terrain feature is determined. The representation of the terrain feature is attenuated if the distance from the reference point to the terrain feature is within a predetermined range. The representation of the terrain feature is displayed.

Abstract: A head up display system for a vehicle that includes a compact image source for projecting an image. The compact image source may be foldable up toward or into a cockpit ceiling of the vehicle, be positioned within a dashboard of the vehicle, or located at another suitable position. A combiner reflects the projected image with optical power toward an observer for observation. The combiner is positioned so that the observer, in a line of sight, may see a visual exterior view of an outside scene through the combiner and the projected image in the combiner. In a preferred embodiment, the image source includes an illumination system that includes a high power light emitting diode (LED) array assembly. A Fresnel lens array is operatively associated with the LED array assembly for receiving light produced by the LED and providing a nearly collimated light output. A spatial light modulator receives the nearly collimated light output.

Abstract: A communication system can utilize a STANAG 5066 profile and include a data rate link mechanism. The data rate link mechanism can reside in a linking layer, such as, a subnetwork management sublayer according to the STANAG 5066 application. The mechanism allows data rate change functions of HF messages to increase throughput upon link establishment. Link quality can be determined by LQA signals generated according to MIL-STD-188-141B profiles.

Abstract: A wideband communications system uses a photomixer, a radio frequency (RF) mixer, and an antenna. The photomixer is comprised of high speed phototransistors that are illuminated by two laser beams. The laser beams are generated by two lasers, one tunable, and conveyed to the photomixer via fiber optic cables. The two beams are mixed by the photomixer to generate a radio heterodyne signal that is mixed with antenna signals to generate an intermediate frequency (IF) signal based on the differences of the generated heterodyne frequency and the antenna signals. Conventional fiber optic means may be used to convey the IF signals, along with the fiber optic cables to the photomixer, to and from a remote RF head located at some distance from the rest of the communications system to overcome losses in transmission lines.

Abstract: A pair of radio frequency communication devices and a communication method are provided according to the invention. A transmitter includes a data source providing a data stream and a radio frequency modulation device. The radio frequency modulation device communicates with the data source and performs a modulation of a carrier wave according to the data stream provided by the data source. The data stream controls one or more modulation characteristics of the carrier wave. A corresponding receiver includes a modulation key and a modulation detector. The modulation key includes a plurality of modulation patterns. The modulation detector receives a radio frequency communication signal and communicates with the modulation key. The modulation detector maps portions of the received communication signal to the modulation key in order to detect modulation characteristics in the received communication signal and to generate a data output.

Abstract: A method of increasing positional awareness of a pilot of an aircraft during a landing approach of the aircraft. First data from a navigational aid is received. The first data is analyzed to determine a first position of the aircraft at a predetermined time. Second data is received. The second data is independent of the first data. The second data is analyzed to determine a second position of the aircraft at the predetermined time. The first position of the aircraft and the second position of the aircraft are compared, and the pilot is alerted to a difference between the first position of the aircraft and the second position of the aircraft. The second data may be displayed in a form that is convenient for the pilot to view during landing.

Abstract: An equalizer is used with complex modulation modems to reduce intersymbol interference. The equalizer includes an equalizer filter that receives an input data signal and adapts to compensate for the noisy communications channels to reduce intersymbol interference to the input signal. A branch metric computer demodulates the equalizer filter adapted input data signal. A decision device delivers an alpha value, starting phase information and confidence values from the demodulated input data signal. A gain determination function receives the confidence values and determines adaptation gain for the equalizer filter. A remodulator receives the alpha value and starting phase information and remodulates the alpha value and starting phase information into a remodulated data signal. A summing function compares the remodulated data signal to a delayed version of the input signal to generate an error signal for the equalizer filter to adjust the equalizer filter.

Abstract: A display includes a light source. The display also includes a filter positioned to receive light from the light source. The filter is a dye-based filter and attenuates light in the infrared range. The filter can be configured to have a very sharp spectral cutoff. The filter can be an NVIS filter. The display can be utilized in an avionic display system with night vision equipment. The filter can include a host polymer doped with a dye including cobalt or nickel.

Abstract: A passive sensing system for determining a physical position of a mechanical device includes an encoding system configured to convert a position signal representative of the physical position of the mechanical device into an encoded signal in a binary format. The sensing system also comprises a plurality of secondary optical paths coupled to a primary optical path positioned between a light source and the encoding system. The encoded signal comprises a plurality of pulses of light each sequentially delayed by the secondary optical paths. A system for determining a physical position of a flight control surface of an aircraft is also disclosed. A method for determining a physical position of a flight control surface of an aircraft is also disclosed. A passive sensing system for determining a physical position of a flight control surface of an aircraft is also disclosed.

Abstract: A system and method for providing configuration management support for an engineering design, the system using an object-oriented database and private workspace to provide for change isolation. The creation of the private workspace is accomplished with a novel “ownership only” full copying approach which is efficient with respect to disk storage space and consumption of computing resources, especially where the database includes many small items which are under configuration management.

Abstract: A monitoring instrument that represents the state of n parameters is disclosed, where n is an integer greater than two. The monitoring instrument includes n axes having a common origination point. Each axis is configured to indicate one of the n parameters. The instrument also includes a polygon having n vertices, wherein each vertex is disposed along one of the n axes at a location indicating the state of the parameter indicated by said axis.

Abstract: A radio has a tunable bandpass filter that is tuned by apparatus within the radio. A reference generator generates a reference signal for use in tuning the tunable bandpass filter. The tunable bandpass filter receives the reference signal and provides a filter output signal. A digital signal processing and control processor is connected to the tunable bandpass filter to receive the filter output signal. The digital signal processing and control processor has a phase comparison function that provides a phase error metric from the filter output signal. The digital signal processing and control processor tunes the tunable bandpass filter to provide a desired phase error metric signal thereby tuning the tunable bandpass filter to the desired center frequency. The digital signal processing and control processor stores tunable filter parameters for the desired center frequency. The tuning process may be repeated for several desired center frequencies of the tunable bandpass filter.

Abstract: A switchable optical system includes a primary optical system positioned to receive a forward view image, forward from the vehicle, during a reconnaissance mode of operation. A secondary optical system is operatively associated with the primary optical system for receiving opposing side images, side-looking from the vehicle. An imaging sensor is operatively associated with the primary optical system and with the secondary optical system. A mode switch is operatively associated with the primary optical system and the secondary optical system for switching between the reconnaissance mode of operation and a biomimetic mode of operation. The forward view image is sensed by the imaging sensor during the reconnaissance mode of operation; and, a portion of the forward view image and the opposing side images are simultaneously sensed by the imaging sensor for balancing the optic flow during the biomimetic mode of operation.

Abstract: A backlight for a liquid crystal display includes a substantially planar waveguide and a plurality of light-emitting diodes positioned adjacent the waveguide. The plurality of light-emitting diodes emits light having a first wavelength range. A reactive element is disposed adjacent the waveguide. The reactive element emits light having a second wavelength range toward the waveguide when the reactive element is excited by light from the plurality of light-emitting diodes.

Abstract: A translator terminal for use with two or more wireless networks is disclosed. The translator terminal allows a first network to communicates with first-type terminals in an encrypted form and a second network to communicate with second terminals in an encrypted form. The translator terminal allows information from the first terminal to be translated to the second terminals, without jeopardizing the encryption format utilized by the first terminals. The translator could be utilized to translate selected information from a Link 16 network to another network.

Abstract: A multi-band wide-angle scan phased array antenna with novel grating lobe suppression has a first plurality of radiation elements for radiating a first frequency arranged in a rectangular configuration. A second plurality of radiation elements for radiating second frequency are arranged in a rectangular frame around the first radiation elements. A third plurality of radiation elements for radiating third frequency are arranged in a rectangular frame around the second radiation elements. The radiation elements are apertures that are ?/2 of an operating frequency in size. The radiation elements may also be arranged in square, circular, or elliptical configurations.

Abstract: A satellite television system that provides live television programming to passengers by integrating direct broadcast satellite services into an in-flight aircraft entertainment system. The system has an antenna disposed on the aircraft that is pointed at a plurality of satellites that are part of a direct broadcast satellite system. The antenna is controlled by an antenna controller and antenna interface unit that send control signals and process status signals to steer the antenna. The antenna is steered to lock it onto RF signals transmitted by the satellites. The antenna interface unit downconverts the received encoded RF signals to provide encoded left hand circularly polarized RF signals and right hand circularly polarized RF signals that contain different sets of television channels. The downconverted encoded RF signals are processed by a receiver to provide encoded video and audio signals of different television channels. The receiver does not decode or D/A convert the downconverted signals.