Abstract: A system and method for determining the locations of freight containers in a freight yard is described. A remote unit that includes a GPS receiver is attached to the freight containers. The remote receivers have an independent power supply—a battery. Intermittently, either by a timer or by a motion detector, the remote receivers are operated. During operation, the remote receivers receive signals from the global positioning satellite system and at an allotted time, transmit the GPS data to a base station before shutting down to conserve power. The base station processes the GPS data to determine a position in the freight yard of each freight container. When a particular freight container or contents is desired, a data base in the base station can be consulted and the contents and location of a particular freight container located. The freight yard is typically outside with a view of the GPS constellation, such as a rail yard, airport baggage area, ship yard, truck park, etc.

Abstract: A global synchronization unit (GSU) for time and space (TS) stamping of input data elements. The GSU comprises a GPS Receiver and an associated antenna for receiving GPS signals from signal sources associated with a GPS system symbolically embedded within a global reference system, and processing received GPS signals so as to automatically produce time and space (TS) stamp data element representative of the time and space coordinates of the GSU with respect to said global reference system at each data sampling instant occurring within the GSU. The GSU further comprises a central processor, operably connected to the GPS Receiver, and also a data input port, operably connected to a data input device and the central processor, for receiving an input data element from the data input device, at each data sampling instant.

Abstract: An inertial reference system for a spacecraft includes an attitude control assembly and a plurality of force sensors. The attitude control assembly is coupled to a spacecraft body at a plurality of attachment points and at least one of the plurality of force sensors is integrated at each of the attachment points. In one embodiment, the force sensors are piezoelectric transducers. In another embodiment, the control assembly is coupled to the spacecraft body at four attachment points. In yet another embodiment, each of the force sensors is preloaded by a bolt that attaches the attitude control assembly to the spacecraft body.

Abstract: A method and system pertaining to a dual antenna compensation algorithm is provided. A local area augmentation system may include a dual antenna system to receive signals from satellites. The system may switch between the antennas to receive signals, and the transition between the antennas should be seamless. Thus, phase variations between the antennas can be determined to correct for code phase variations, and hardware delays between the antennas can be determined to correct for delay differences in signals received from both antennas.

Abstract: In a satellite ranging system predetermined bit sequence or group of bit sequence in a transport stream, which is a digital signal are used to generate trigger signals on the basis of which the delay introduced into the transport stream by the travel path from a satellite ground station to the satellite and back or to another satellite ground station is determined allowing a calculation of the distance between the ground station(s) and the satellite. The predetermined bit sequence or group of bit sequences may be inserted into the transport stream at the uplink site, for example as a specific payload P. In order to avoid insertion of additional packets the transport stream or part of it may be used as a predetermined bit sequence.

Abstract: The present invention is a system for providing GPS users with a high level of confidence in the integrity and accuracy of received GPS signals. The system provides a means for each GPS satellite itself to verify the accuracy and/or integrity of its own operations by calculations and processing internal to the GPS satellite and by crosslink communications with other GPS satellites in the GPS constellation. After a GPS satellite verifies the accuracy and/or integrity of its own signals, the GPS satellite transmits an integrity message to all GPS users in view of the satellite. The integrity message can alert GPS users to a loss of integrity or accuracy in the GPS signals. Alternatively, the integrity message can contain information to correct errors in the GPS signals. The integrity message can be incorporated into the existing GPS navigation message transmitted by GPS satellites, or the integrity message can be transmitted over a separate channel such as the planned L5 band channel.

Abstract: The invention concerns a system comprising a radiofrequency antenna stationed in an orbit around the earth, and illuminating means for transmitting and/or receiving likewise orbiting round the earth located on at least a satellite separate from the one bearing the antenna, the antenna being located in the illuminating field of said means. The invention is characterised in that the antenna is a radiofrequency antenna formed by a mesh generation of tiles and phase-shifting means connected thereto, the signals received by the tiles passing through the phase-shifting means before being assembled on said tiles, said phase-shifting and/or delaying means being capable of diverting the radiofrequency signals corresponding to one or several channels transmitted by the illuminating means to send them to the earth along one or several beams and/or of diverting the radiofrequency signals corresponding to one or several beams transmitted from the earth to send them to the illuminating means along one or several channels.

Abstract: The invention relates to a method and to devices for determining in a positioning system the time of reception of a beacon signal which was received and tracked by a receiver. In order to enable a re-acquisition of the system time based on a noisy received signal, it is proposed that the method comprises as a first step reconstructing a beacon signal for an interval based on available information. Then, a cross-correlation is performed between the reconstructed signal and the received signal at different relative positions to each other. Next, the time of transmission of the received signal is determined based on information for the reconstructed signal and on the relative position resulting in the maximum correlation value. Finally, a time of reception of said received signal is determined as the sum of the determined time of transmission of the received signal and of a calculated time of flight of the received signal.

Abstract: An information system for providing services including traffic and navigation services, as well as other information services to a driver. One versions of the system makes use of existing components of a wireless telephone system, for example, by using the input and output capabilities of a telephone handset. Another version is a portable system that includes multiple switches for initiating access to a remote server in one of a number of operating modes. For instance the system has switches for initiating traffic information, roadside assistance, personal information, or emergency modes. The system includes a positioning system for generating position data related to a geographic location of the system, and a wireless communication device. The system also includes an audio output device, such as a speaker for presenting the received information. The system can also include a storage for a unique identification of the information system.

Abstract: A method determines range from a moving platform to an emitter. The method receives a RF signal from the emitter; counts a number of phase reversals of the received RF signal during a period of time; measures a Doppler frequency during the period of time; and determines the range to the emitter based on both the number of counted phase reversals and the measured Doppler frequency.

Abstract: A location determination apparatus, method and system (10, 23, 26, 32, 36, 48, 52, 60, 64, 74, 78, 84, 90, 106) that is an improvement upon existing location determining techniques. The invention enables precision indoor location determination through the use of non-DTV terrestrial broadcast signals (e.g. one way, wide area, dissemination of information)(20), or re-broadcast signals (44, 56, 70, 80) of the proposed (terrestrial based) digital satellite radio relay transmitters (42, 54) to provide position location. This solution does not require a local receiver to correct for long distance propagation dispersion, particularly for the satellite relay, as the digital radio satellites are already synchronized to GPS time.

Abstract: A perimeter threshold of an area is defined. The location of a device (102) is tracked using a first location technology (108) when the device (102) precedes the perimeter threshold. The location of the device (102) is tracked using a second location technology (100) when the device (102) exceeds the perimeter threshold.

Abstract: Provided is a Doppler based automated direction finding system that detects radio frequency (RF) leaks in a cable television plant. During a ride-out, the system detects leaks and stores leak data, such as amplitude, location, and bearing. The stored data is uploaded to a computer that performs a leak analysis. The leak analysis isolates the leaks using Doppler-based bearing information and separates cable leaks from other RF sources, such as power sources and noise. Erroneous information that results from RF reflections (multi path) may be eliminated while processing the data using triangulation. After the leak analysis, the computer generates work orders and maps, makes the data available to users, and may also compile information and file reports based on the data.

Abstract: A method of and apparatus for passively determining agile-frequency-emitter location and computer-readable medium bearing instructions therefor. Unless a specified accuracy threshold is met or exceeded, phase, frequency, and baseline position are measured during a single receiver dwell and processed. An array of gains and phase difference ambiguity integers for all phase difference measurements are computed. An emitter DOA unit vector or COS(AOA) is estimated and an LBI phase difference is predicted. If the rank of the set of baseline-frequency product differences is greater than 1, each DOA unit vector is projected and scaled by the measured frequency corresponding to the baseline measurement. Otherwise, if the rank is 1, the product of the COS(AOA) and baseline length is formed and scaled by the measured frequency.

Abstract: A method and apparatus for setting coarse GPS time in a GPS receiver in a mobile station (MS) that is communicating with a base station and a position determining entity (PDE). The MS requests an assistance message from the PDE that includes a sequence of predicted navigation bits, including a predicted time indicator field, which is then located and decoded. Coarse time is set responsive to the time indicator value. A Pattern Match Algorithm may be performed to provide more precise GPS time. In order to better set coarse time, an expected error in the Time of Week may be determined, by for example using the expected network latency. The system describe herein enables the use of IS-801 protocol by an MS in asynchronous networks by improving the coarse time setting process.

Abstract: A geo-location technique for use in mobile communications networks employs both FDD and Time Division Duplex (TDD) modes of operation, and is applicable when both FDD and TDD systems are jointly deployed or both FDD and TDD modes of a wireless system such as UMTS are jointly activated. It has been determined that the near-far interference can be much easier controlled on purpose in the TDD mode than in the FDD mode thanks to the slotted data transmission nature of a TDD system that permits adjustment of the interference level at the time slot level instead of the frame level. Indeed, in a TDD system, loading and interference levels can be gracefully decreased in a single time slot without harming the ongoing traffic or complicating the power control operations, as would be the situation in a UMTS FDD system via IPDL or similar solutions that require to mute the pilot transmission. The invention applies to both situations whether or not the terminals are equipped with a dual receiver.

Abstract: A communication system is formed by a location information providing unit configured to provide a location information indicating a location of each road related facility arranged along a road, and a communication unit installed on each road related facility, configured to transmit the location information of each road related facility to a terminal device of a user on the road by using weak radio signals, such that the terminal device that can receive the weak radio signals can detect a location of the terminal device according to the location information.

Abstract: A vehicle information system which includes an in-vehicle system 105 and a centralized server system 120. The in-vehicle system communicates with the server system using a wireless communication link 110, such as over a cellular telephone system. A position system, such as a set of GPS satellites 140, provides positioning signals that are used by the in-vehicle systems, and optionally by the centralized server system to increase the accuracy of position estimates. In one version of the system, an operator specifies a destination to an in-vehicle system which validates the destination. The in-vehicle system transmits specification of the destination to a server system 125 at the centralized server. The server system computes a route to the destination and transmits the computed route to the in-vehicle system. The in-vehicle system guides the operator along the route.

Abstract: An improved GPS signal receiver (and corresponding method of operation) includes a plurality of antenna elements each receiving a plurality of GPS signals (e.g., GPS LI signals or GPS L2 signals). A plurality of mixers (which correspond to the array of antenna elements) and a combining node convert the GPS signals received at the antenna elements in a frequency-division-multiplexed (FDM) manner over FDM frequency bands logically assigned to the antenna elements to produce a composite signal representing such GPS signals. An analog-to-digital converter converts an analog signal derived from the composite signal (which may be an intermediate frequency signal or a baseband signal) into a digital word stream. Demultiplexing logic extracts GPS signal components in the digital word stream. The GPS signal components correspond to the FDM frequency bands logically assigned to the antenna elements.

Abstract: A personal surveillance system configured to be worn by an individual includes a communication system configured to record communication files, a locating system configured to determine a location of the personal surveillance system, and a transmitter configured to send the communication files and the location of the personal surveillance system to a remote monitoring station. The locating system includes a satellite system interface configured to determine the location of the personal surveillance system and an alternate positioning system configured to determine the location of the personal surveillance system in at least one situation where the satellite system interface cannot determine the location of the personal surveillance system.