Abstract: A communication management system and technique that provides a flexible yet efficient means of coordinating communications between an Earth bound user and a non-geosynchronous orbit (NGSO) satellite constellation. The system distributes the majority of the management of communications links to operations and control center and the ground based users. Therefore, the responsibility for handling communication management is performed by the ground based users and control center as opposed to being the responsibility of the NGSO satellites. This allows the NGSO satellites to be minimized in size and cost while maximizing the resources available to users. Furthermore, the ground based systems may be more easily updated and maintained than would be the case if the satellites were responsible for this task.

Abstract: A fixed terrestrial user terminal antenna for use with a satellite communication systems in which satellites orbit earth in a constellation comprised of a plurality of spaced orbital planes with each orbital plane of the plurality of orbital planes having a plurality of satellites. The user terminal antenna comprising a base with a tilt plate connected to the base. The tilt plate having a one-dimensional electronically scanned phased array antenna that scans along a single axis is attached to the tilt plate so that the array antenna tilts with the tilting of the tilt plate. The array antenna tracks individual satellites of the plurality of satellites in an orbital plane of the plurality of orbital planes as the individual satellites travel through a field of view of the array antenna.

Abstract: A system for providing wireless communication within a local area network (LAN) onboard a mobile platform. The system includes at least one seat transceiver located in a passenger seating area, and at least one passenger service unit (PSU) located above the passenger seating area. The PSU includes at least one PSU transceiver. Additionally, the system includes a direct path infrared (IR) signal transmission link between the seat transceiver and the PSU transceiver. The direct path IR transmission link transmits data between the seat transceiver and the PSU transceiver.

Abstract: A satellite communication system includes a constellation of non-geostationary orbiting satellites following a fixed ground track on the earth, and ground terminals having substantially continuous visibility to at least one of the satellites in a single ground track. Each of the satellites in the constellation follows a single substantially linear track across the sky when observed from the earth. In a preferred embodiment, the system can also include ground terminals which have an antenna with a single axis of scanning motion. In this embodiment, satellites have repeating ground tracks wherein a satellite completes n orbital revolutions each time the earth rotates through 360 degrees, wherein n is an integer between 2 and 15, inclusive.

Abstract: A communication system and method for transmitting data to mobile platforms using multiple simultaneous channels operating at multiple data rates. Each mobile receiver has the capability to receive multiple transmit channels at multiple data rates. Aircraft report their position to a ground based controller which determines which communication channel can be operated without substantial loss of data. Data packets destined for each aircraft are preferably routed to the highest data rate channel that can be received by that aircraft without substantial loss of data. This maximizes the overall system efficiency and throughput. High priority and mission critical data may be transmitted to the aircraft using low data rate channels to increase link availability.

Abstract: A polling system and method for establishing forward and return communication links with a plurality of mobile platforms operating within a given coverage region, and further which provides preliminary return channel assignments with each polling message. Each polling message further has an associated ID code designating a particular mobile platform which is registered with a network operations center (NOC) of the system. If the mobile platform does not respond on its designated preliminary return channel within a given time period (e.g., 5 seconds) than the preliminary return channel is returned to a database of available return channels. Polling is carried out more expeditiously because groups of mobile platforms are polled simultaneously and provided with preliminary return channels which accompany the polling messages, and which direct each mobile platform to a designated return channel to use in establishing a return communications link.

Abstract: A method and apparatus for identifying which one of a plurality of mobile terminals in communication with a ground-based base station, via a transponded satellite, is causing interference with a non-target satellite orbiting in a vicinity of the transponded satellite. The method involves using the base station to sequentially check each of the mobile terminals to identify which one is causing the interference. The check is made by the base station commanding each mobile terminal to modulate the power level of its transmitted signals and then checking with an operator of the interfered with non-target satellite to see if the interference condition has changed. Once the mobile terminal causing the interference condition is identified, the base station can command the mobile terminal to reduce it transmit power accordingly.

Abstract: A system and method for quickly detecting and remedying an interference incident caused by one of a plurality of mobile terminals in communication with a transponded satellite. The method makes use of a time line constructed from communications of each of the mobile terminals. The time line forms a real time, sequential record of events wherein various mobile terminals have made contact with the transponded satellite. The method extrapolates from the time line which one of the mobile terminals has caused an interfering event by determining which mobile terminal accessed the communication system just prior to the interference event arising.

Abstract: A method for rapidly monitoring and detecting a mobile terminal causing RF interference with one or more satellites orbiting in the vicinity of a target satellite, from a plurality of mobile terminals accessing the target satellite. Each mobile terminal performs a transmit lobing signal sequence and a ground-based component in the form of a Network Operation Center (NOC) analyzes the signals transmitted by each mobile platform. The NOC determines a ratio of energy-per-bit to noise spectral density (Eb/No) value for the signals transmitted by each mobile platform and compares these values to a predetermined Eb/No value. If the Eb/No values for a given mobile platform deviate by more than a predetermined magnitude from the predetermined Eb/No value, then the NOC identifies that given mobile platform as causing the unintended RF interference with the adjacent satellite(s).

Abstract: An apparatus and method for correcting antenna beam misalignment between a transmit antenna and a receive antenna on a mobile platform such as an aircraft. The beam alignment method makes use of sequential lobing to determine the pointing angles in azimuth and elevation of a receive beam received by the receive antenna. For the transmit antenna, sequential lobing is used for the transmit antenna beam transmitted to a transponded satellite and then to a ground station. The ground station performs received signal strength indicator (RSSI) measurements and transmits these measurements back to the aircraft 16 via the target satellite. From these measurements, the beam misalignment between the receive and transmit antenna beams, both in azimuth and elevation, can be determined and a correction applied to the transmit antenna.

Abstract: A system for bi-directional data content transfer between a plurality of mobile platforms, such as aircraft or cruise ships, and a ground-based control segment. The system includes the ground-based control segment, a space segment and a mobile system disposed on each mobile platform. The ground-based control segment includes an antenna which is used to transmit encoded RF signals representative of data content to the space segment. The space segment includes a plurality of satellite transponders, with one of the transponders being designated by the ground-based control segment to transpond the encoded RF signals to the mobile system. The mobile system includes steerable receive and transmit antennas. The receive antenna receives the encoded RF signals from the satellite transponder, which are thereafter decoded by a communications subsystem and transmitted to a server. The server filters off that data content not requested by any occupants on the mobile system.

Abstract: A system and method for managing access to a satellite-based transponder by a plurality of aircraft each having a mobile radio frequency (RF) system. The system employs a ground-based, central control system for managing access to the satellite-based transponder so that the aggregate power spectral density (PSD) of the RF signals of all the mobile systems does not exceed, at any time, limits established by regulatory agencies to prevent interference between satellite systems. This is accomplished by a dual control loop arrangement for monitoring the signal-to-noise ratio (Eb/No) of the RF signal transmitted by the satellite-based transponder. A ground-based control loop is used whereby a ground-based central controller monitors the Eb/No and transmits commands to the aircraft (via the satellite transponder) to maintain the Eb/No of the transmitted signal within a predetermined range.

Abstract: A system and method for managing access to a satellite-based transponder by a plurality of aircraft each having a mobile radio frequency (RF) system. The system employs a ground-based network operations center (“NOC”) having a central control system for managing access to the satellite-based transponder so that the aggregate power spectral density (PSD) of the RF signals of all the mobile systems does not exceed, at any time, limits established by regulatory agencies to prevent interference between satellite systems. This is accomplished by accurately estimating the PSD of each mobile terminal at the NOC using a reverse calculation method to determine mobile terminal EIRP and then using antenna models to project the EIRP on to the GEO arc. Accurate knowledge of the mobile terminal location and attitude is acquired through periodic reports sent from the mobile terminal to the NOC.

Abstract: An optical sensing system for sensing the temperature at a first location, including: electro-optical unit for producing a modulated optical signal and a light guide unit for receiving and transmitting the modulated optical signal along an optical path. The optical system further includes temperature sensing fiber which receives and guides the modulated optical signal along a temperature sensing optical path. One portion of the modulated optical signal serves as a reference optical signal and another portion of the modulated optical signal serves as a target optical signal. The optical sensor system also has a transducing unit, which receives the reference optical signal, the target optical signal having first and second time delays with respect to a chirped rf signal from the electro-optical unit. The transducing unit produces a multi-frequency electrical signal which includes a first frequency corresponding to the first time delay a second frequency corresponding to the second time delay.

Abstract: An optical sensing system with a rotation sensor head for sensing the rotation of a rotatable object while simultaneously sensing the position of a displaceable object with a position sensor head. An electro-optical unit outputs a modulated optical signal and a chirped rf signal. The envelope of the modulated optical signal has a phase that has a known relation to the phase of the chirped rf signal. The electro-optical unit is coupled to a light guide element and receives and transmits the modulated optical signal along an optical path for reflection off a disk secured to the rotatable object in order to provide a rotation sensing optical signal. A transducing unit receives the rf signal at one input and has another input optically coupled to receive the rotation sensing optical signal while simultaneously receiving position sensing optical signals from the position sensor heads.

Abstract: An optical position sensing system for sensing the position of a displaceable element. An electro-optical unit outputs a modulated optical signal and a chirped rf signal. The envelope of the modulated optical signal has a phase that has a known relation to the phase of the chirped rf signal. The electro-optical unit is coupled to a light guide element and receives and transmits the modulated optical signal along an optical path for reflection off a surface of the displaceable element in order to provide a position sensing optical signal. A reference reflecting element is disposed in the optical path upstream of the displaceable element for partially reflecting the transmitted modulated optical signal in order to provide a reference optical signal.

Abstract: One or more decoys (22) are towed by an aircraft (18) to confuse hostile radar. The tow lines (20) to the decoys (22) include fiber optic components which optically transmit to the decoys (22) both radio frequency signals for retransmission to hostile radar (24), and direct current power. The fiber optic components absorb strain forces imposed by towing the decoys (22). Multiple decoys (22) are deployed at varying distances from the aircraft (18) to increase the overall range of frequencies covered by the system, simulate a plurality of false targets, or accomplish angle gate deception. The deception may be accomplished by transmitting signals from the decoys in sequence and can be enhanced by dynamically varying the power levels of the decoy transmitting antennas. The fiber optic components may be separate optical fibers deployed separately or joined together for simultaneous deployment. The preferred configuration is a single optical fiber with coaxial inner and outer cores.

Abstract: One or more decoys (22) are towed by an aircraft (18) to confuse hostile radar. The tow lines (20) to the decoys (22) include fiber optic components which optically transmit to the decoys (22) both radio frequency signals for retransmission to hostile radar (24), and direct current power. The fiber optic components absorb strain forces imposed by towing the decoys (22). Multiple decoys (22) are deployed at varying distances from the aircraft (18) to increase the overall range of frequencies covered by the system, simulate a plurality of false targets, or accomplish angle gate deception. The deception may be accomplished by transmitting signals from the decoys in sequence and can be enhanced by dynamically varying the power levels of the decoy transmitting antennas. The fiber optic components may be separate optical fibers deployed separately or joined together for simultaneous deployment. The preferred configuration is a single optical fiber with coaxial inner and outer cores.

Abstract: The RF/microwave switch/modulator uses an optically controlled diode 20. The reactance of the diode may be varied by varying the illumination intensity. In this fashion, the photodiode in conjunction with an external circuit can switch or modulate a microwave signal by varying the reactance of the diode using a laser light source or the like. The bias voltage may be varied to electronically tune the diode so that the microwave frequency of operation can be electronically controlled.

Abstract: A fiber optic radar guided missile system 10 is disclosed which includes a radar receiver 12 disposed in a missile for receiving radar reflections and providing a first optical signal in response thereto. An optical receiver 14 is disposed at a launcher for receiving the first optical signal and for providing a set of electrical signals in response thereto. A fiber optic link 32 is connected between the missile and the launcher for communicating the first optical signal from the radar receiver 12 to the optical receiver 14.In a specific embodiment, the invention 10 includes a first system 12 disposed in a missile for receiving radar reflections which includes only an antenna 16 for receiving radar reflections, a radar seeker 18 for providing a first electrical in response to the received radar reflections, and a first fiber optic transmitter 26 for converting the first electrical signal into a first optical signal.