Abstract: A system and method capable of mitigating the migration from the current GPS system to the Galileo system and allow a single satellite system positioning receiver to process both GPS signals and Galileo signals.

Abstract: A method, apparatus, and computer-readable media for determining the position of a user terminal comprises receiving at the user terminal a broadcast television signal from a television signal transmitter; determining a first pseudo-range between the user terminal and the television signal transmitter based on a known component of the broadcast television signal; receiving at the user terminal a global positioning signal from a global positioning satellite; determining a second pseudo-range between the user terminal and the global positioning satellite based on the global positioning signal; and determining a position of the user terminal based on the first and second pseudo-ranges, a location of the television signal transmitter, and a location of the global positioning satellite.

Abstract: A system and a method for position determination by impulse radio using a first transceiver having a first clock providing a first reference signal and a second transceiver placed spaced from the first transceiver. The system determines the position of the second transceiver. The second transceiver has a second clock that provides a second reference signal. A first sequence of pulses are transmitted from the first transceiver. The first sequence of pulses are then received at the second transceiver and the second transceiver is then synchronized with the first sequence of pulses. A second sequence of pulses are transmitted from the second transceiver. The first transceiver receives the second sequence of pulses and the first transceiver is synchronized with the second sequence of pulses. A delayed first reference signal is generated in response to the synchronization with the second sequence of pulses.

Abstract: An apparatus and method for locating a remote station in a synchronous communications network using the time of arrival of a reference pilot signal at the remote station as a time reference. The time difference of arrival (TDOA) of GPS signals received by the remote station and other signals received from a base station, are measured relative to this reference time. From these measurements, the location of the remote station is determined. The invention treats the location issue as a TDOA problem.

Abstract: An artificial satellite navigation system and method. The artificial satellite navigation system includes a global positioning system (GPS) receiver, local satellite, and remote satellite absolute navigation units estimating the position and velocity of a local satellite or a remote satellite and bias and drift of a clock in the receiver. A difference calculation unit calculates differences in position and velocity from the local satellite and remote satellite absolute navigation units. A relative navigation unit estimates the relative position and velocity of the local satellite with respect to the remote satellite. The relative navigation unit navigates the local satellite relative to the remote satellite.

Abstract: A directional finding system for providing a corrected compass bearing based upon true north rather than magnetic north for a selected location. The true bearing is calculated by determining a present position with a GPS receiver or other location finding device, then selecting the deviation between true north and magnetic north for the present position from a store of magnetic deviation data, and finally correcting the magnetic bearing by the deviation to find a true bearing. The store of magnetic deviation data comprises the deviation between true north and magnetic north for any location. Additionally, the true bearing can be further corrected by a time-based magnetic deviation based upon the monotonic movement of the magnetic north pole. The true bearing is presented on a display along with the magnetic bearing and the present position.

Abstract: Assessing performance of satellite constellations. For a given constellation of satellites, each having a given number of sensors, a method is disclosed for determining the times of access between each sensor and a plurality of targets located on Earth. Calculation time required for determining access is greatly decreased using pre-computed access calculations as a baseline.

Abstract: A user terminal (110) includes a rotating electronically steerable antenna system (210) which combines coarse mechanical beam steering with fine electronic beam steering to provide full hemispherical coverage and enable hand-offs in a satellite communication system. The antenna system (210) comprises at least one antenna unit (and preferably two antenna units) including a mechanically rotatable base (330), an antenna holder (320) coupled to the mechanically rotatable base, and two electronically steerable antenna subunit (310) mounted on the antenna holder. Antenna system (210) also includes an antenna unit controller (260) adapted to control rotation of the mechanically rotatable base (330).

Abstract: Transfer/in-flight alignment technique using a Doppler velocity sensor. An aircraft navigation system (10 and/or 20), a Doppler velocity sensor (50) and an alignment filter (45) are used to align the inertial navigation system (4) of a slave vehicle. The velocity (and/or position) of the aircraft navigation system, the velocity (and/or position) of the slave vehicle's inertial navigation system (40) and the velocity measurement of a Doppler velocity sensor (50) are used to generate the measurements of the alignment filter (45). The DVS and aircraft navigation system are used simultaneously to align the inertial navigation system of the slave vehicle. A GPS receiver (60) with a GPS antenna (70), a Doppler velocity sensor (50) and an alignment filer (46) are used to align the inertial navigation system (40) of a flight vehicle.

Abstract: A tracking system for maintaining an alignment between a reflector antenna and a source of electromagnetic radiation, includes a reflector for reflecting electromagnetic radiation generated from a electromagnetic radiation source, a receiver, and a rotary sub-reflector which is positioned in front of the reflector for deflecting the radiation reflected by the reflector to the receiver and for generating triggering signals for measuring the strength of signals of the reflected radiation, whereby the sub-reflector is arranged at an inclination with respect to the reflector by an offset angle.

Abstract: A locator system for quickly disseminating stored information about the lost person or item utilizes input data in text, pictorial and video form which is selectively sent to facilities that can use the information (text, pictorial and video to TV stations; text and pictorial to police; text to radio; text and pictorial to the internet). The system also utilizes a GPS system and a receiver on the person or item to be located to aid the police in finding the location of the person or item.

Abstract: A method and apparatus for determining a position of a mobile satellite positioning system (SPS) receiver. In one example of a method, a cell object information is determined; this cell object information comprises at least one of a cell object location or a cell object identification. An altitude is determined from the cell object information which is selected based upon a cell site transmitter which is in wireless communication with a cell based communication system which is coupled to (and typically integrated with) the mobile SPS receiver. The position of the mobile SPS receiver is calculated using the altitude which is determined from the cell object information. In another example of a method, an altitude pseudomeasurement is determined from an estimate of an altitude of the mobile SPS receiver.

Abstract: The mobile cellular telephony terminal includes a radio transmitter/receiver (1) for communicating with base stations of a cellular network, measuring the Doppler velocity of the transmissions originating from the stations and accordingly operating circuits (2) for estimating the velocity of the terminal, by composition of the Doppler velocities, and updating circuits (4, 5) are provided for updating an inertial unit (10) supplying the radio circuit (1) with the position of the terminal, by comparison between a terminal velocity supplied by the unit (10) and the estimated velocity.

Abstract: Disclosed is a GPS pseudolite transmitter, receiver and navigation system. The GPS pseudolite transmitter is adapted to transmit a first phase modulated L-band signal at a first signal pulse repetition rate having an associated first period time duration. The first phase modulated L-band signal is modulated with a short period code having a code epoch of at least about one millisecond. For each consecutive transmission pulse having the first period time duration, the pseudolite transmitter transmits the first phase modulated L-band signal during less than one half of the first period time duration, and for at least about 1 millisecond so that the first pseudolite transmitter transmits an epoch of the short period code during each transmission pulse.

Abstract: A position detecting system capable of making communications with a plurality of pointing devices without changing resonance circuits of said pointing devices, and a pointing device suitable for the position detecting system. The position detecting system detects positions of at least two cordless pointing devices on a two-dimensional plane and is equipped with a command electromagnetic wave transmitting circuit to transmit a command to the pointing device.

Abstract: A base station receives GPS signals from GPS satellites and transmits a combined differential GPS (DGPS) signal and a command signal. At least one pseudolite receives the DGPS and command signals and combines the DGPS and command signals with a pseudo-GPS signal. A GPS receiver on a mobile machine receives GPS signals from GPS satellites, and the combined signal from the pseudolite. The position signals are delivered to a machine position processor to generate a machine position signal. The command signals are delivered to a machine control processor to generate a machine control signal. The machine position signal and the machine control signal are delivered to a machine navigator to control the mobile machine.

Abstract: Without use of separate auxiliary antennas, adaptive nulling automatically reduces jamming or other interference affecting a radar or IFF system. A primary beam forming network utilizes four-port directional coupler devices, each having an ancillary port which would have been resistively terminated in the absence of the invention. Signals from ancillary ports are coupled to an auxiliary beam forming network to form auxiliary beam patterns which are orthogonal to and track steered main beam patterns. Auxiliary signals are received via the auxiliary beam patterns. Least mean square (LMS) control loops operate on a feedback basis to derive weighted auxiliary signals responsive to jamming signals. The weighted auxiliary signals are combined with the primary received signals (which may be sum and difference signals) in reverse polarity, so as to be additively destructive of the jamming signals. Multiple LMS control loops enable nulling of jamming signals simultaneously in sum and difference channels.

Abstract: A system for use with an inertial reference system and a global position receiver for calculating a position error after a loss of integrity by utilizing the global position system values for position and velocity at a time just before the loss of integrity and by utilizing the inertial reference system position modified by the known error in inertial reference system position as it varies with time and the position error as calculated by the global position system velocity extrapolated over the time since integrity loss.

Abstract: A method and apparatus for a portable communication device, such as a mobile radio terminal in a CDMA network, to identify its geographic location. A communication network comprises multiple base stations which transmit pilot signals, where the pilot signals of one base station are offset from the pilot signals of other base stations by integral multiples of a substantially fixed duration. Associated sync channel messages are also transmitted from which the geographic location of the base stations may be extracted. A portable communication device identifies its location by calculating the delay between the arrival time of a pilot signal from a primary base station and the arrival times of pilot signals from at least two other base stations. For each pair of base stations corresponding to one of the calculated delays, the portable communication device initially specifies its location as being on a selected one of three curves.

Abstract: An apparatus and method are disclosed of providing position indicating signals to a GNSS receiver in an area of poor reception of satellite signals from the GNSS or when a dedicated system under local control is required. The method includes the steps of disposing a plurality of stationary transceivers proximate the area of poor reception and calculating a global position of each stationary transceiver based upon information contained within signals received from at least some satellites of the GNSS. The method further includes the steps of transmitting a local global positioning signal from each of the stationary transceivers to the GNSS receiver in the area of poor reception, such local global positioning signals including at least the global position of the transmitting stationary transceiver.