Abstract: A circuit for applying a compensating ripple signal at a low voltage point, such as the collector electrode of a travelling wave tube to compensate for pulse-top ripple extant on a high voltage pulse applied at the travelling wave tube cathode, to provide a substantially constant voltage across the travelling wave tube during pulsing to preserve its radio frequency phase and amplitude characteristics. The portion of the pulse-top including the undesired ripple is compared against the applied compensating collector signal and the result is digitized and stored discretely in a plurality of sample bins over the duration of the modulation pulse. The stored digital values are updated over a plurality of successive modulation pulses until an equalibrium is reached, a random access memory being arranged to provide a readout over one half of each of the sample bins and to receive updating in the remaining halves of the corresponding sample bins.

Abstract: A GPS (Global Positioning System) aircraft guidance system for use with circular cultivated agriculture fields. The system of the present invention includes a GPS receiver adapted to determine a present position, ground track, and ground speed of an aircraft. The GPS receiver is also adapted to store a configuration of a circular cultivated agricultural field and to compute a desired flight path for achieving an optimal coverage of the field. Deviations of the aircraft from the desired flight path are also determined. The GPS receiver is further adapted to generate a dispense signal which indicates when to dispense agricultural chemicals from the aircraft. A guidance indicator is coupled to the GPS receiver for providing guidance information to the pilot. The guidance indicator is adapted to indicate the aircraft's deviation from the desired flight path and indicate whether the dispense signal is asserted.

Abstract: This novel mobile CDMA station incorporates the global positioning system (GPS). Two modes of operation are possible. One, during GPS operation, there is no transmission or reception of CDMA services. Two, simultaneous CDMA transmissions and reception of GPS are provided. When the mobile receiver is in the CDMA mode, a signal path selector selects the CDMA RF section and the GPS RF section is powered down. During GPS operation, the GPS RF section is selected and the CDMA section is powered down. When CDMA operation is compared with GPS, the average current draw can be less, as the system swaps between the RF sections. The GPS RF section may accept an antenna input from a multi-band antenna network or a separate GPS antenna. The GPS signal is propagated through the existing CDMA channel select filter, having a 1.23 MHz bandwidth and is processed in a base-band signal processor.

Abstract: A receiving system 100 is disclosed which includes at least one antenna 101 providing a plurality of antenna beams providing signal diversity between communicated signals. A first processing branch 103 is included for processing a first plurality of signals appearing within a first plurality of the antenna beams. The first processing branch 103 includes a plurality of signal paths, some of which include delays 105, each receiving a one of the first plurality of signals from a corresponding one of the first plurality of antenna beams. Delays 105 apply a predetermined amount of delay proportionate to the corresponding one of the beams. First processing branch 103 further includes a combiner 106 for combining the first plurality of signals after output from the plurality of signal paths. A second processing branch 104 is provided for processing a second plurality of signals appearing within a second plurality of the antenna beams.

Abstract: In a far field monitor apparatus, each of first and second ILS localizers includes a receiving antenna, a plurality of couplers, a combiner, a receiver, and a first detector. The receiving antenna is formed from a plurality of antenna elements symmetrically arranged in a direction perpendicular to the longitudinal direction of a runway. The receiving antennas of the first and second ILS localizers oppose each other. The couplers are arranged in units of antenna elements to pick up some of signals obtained by the antenna elements in a predetermined amplitude and phase. The combiner combines output signals from the couplers. The receiver receives a combined signal output from the combiner. The first detector detects, on the basis of a receiving signal output from the receiver, a predetermined monitor parameter representing the radiation state of a radio wave radiated from the opposing-side ILS localizer.

Abstract: An automatic array calibration apparatus which is capable of periodically calibrating beamforming offsets using internally generated calibration and test signals. The apparatus preferably includes a calibration signal generating unit which generates a continuous wave calibration signal which is input into a receiving channel as the input signal. I/Q signals are obtained from reception data channels which have been provided with the calibration signal. The apparatus also includes a loop back operation in which test signals are injected in transmission data channels, and are prepared for transmission at a transmission unit. The transmission signal is looped back to the receiving unit and I/Q signals are obtained from reception data channels supplied with the transmission signals.

Abstract: The invention relates to a position determining system, for receiving digital telephone signals transmitted by a number of transmission sources BTS. The system has a pair of receiving stations, CBU and CRU, one at a known position O and another on a roving object R; a position determining processor CPP; and means for passing a link signal, L1 and L2, from each of the receiving stations to the position determining processor, the link signal containing information about the signals received at the receiving station from the transmission sources. Each of the receiving stations is arranged to receive the signals from the respective transmission sources substantially simultaneously. The position determining processor is arranged to compare the information received from the one receiving station with the information received at the other receiving station, and to determine the time delay between the respective signals received at both receiving stations in order to determine the position of the roving object.

Abstract: A communication station for generating or receiving an angularly dispersed array of radiation beams, comprising an array of radiating elements (100) defining an array antenna (1); and a beam former (120), the beam former comprising a passive network having a first side (X) carrying a plurality of beam ports for electrical signals corresponding to the beams and a second side (Y) carrying a plurality of antenna ports corresponding to the radiating elements, each beam port being connected to a plurality of antenna ports via a network (50) of power divider (52) and phase shifter (53) components, the phase shifts of which are in integer multiples of a predetermined constant, so as to generate the array of beams; in which the array antenna (1) has triangular or hexagonal symmetry and the array of beams has triangular or hexagonal symmetry.

Abstract: A collection/delivery work support system which can eliminate erroneous delivery of goods, missing delivery and missing collection in collection/delivery service to greatly improve the efficiency of collection of goods. A collection/delivery navigation system for determining and indicating a route for delivery and collection of goods and managing collection and delivery conditions has an electronic slip which stores information described in a slip of a commodity and has a function of transmitting the stored information in response to an external request for information, and a navigation unit for indicating a route for collection and delivery of goods and collection and delivery conditions.

Abstract: In order to determine a position of a mobile station in a wireless communication system including a plurality of mobile stations each having a wireless communication terminal installed therein, a plurality of base stations and a communication control station, times of receipt at which a radio wave emitted by a wireless communication terminal provided in a mobile station whose position is to be determined are received by at least three base stations substantially synchronized with a standard time are measured, a plurality of representative points are set on a position calculation area within an overlapped portions of cover areas of these base stations, communication delay times at respective representative points are calculated with [(x−xi)2+(y−yi)2]½/C (C is a velocity of light), wave emitting times TMi are calculated as differences between the times of receipt Ti and the communication delay times, a sum D of squares of differences between two calculated wave emitting times i

Abstract: A signal conversion device that provides RTCM correction data to a position determination device. The signal conversion device receives RTCM signals that are converted into a frequency adapted to be received by a position determination device so as to produce a converted correction signal. In one embodiment, the signal conversion device also converts the received RTCM correction data into a format that is adapted to be received by the position determination device. In one embodiment, the received RTCM signal is converted into is the Wide Area Augmentation System (WAAS) format. Alternatively, the signal is converted into a different format such as a particular manufacturer's own format. The converted correction signal is coupled to a position determination device via a wireless link. The position determination device uses the RTCM correction data contained in the converted correction signal for accurately determining position.

Abstract: The invention relates to an antenna installation with an omni-directional antenna (M) and with an auxiliary antenna (A1) the reception signals from which can be combined in respect of amplitude and phase in such a way that a reception miniumu is produced in a desired orientation in space.

Abstract: A wearable device is configured for navigating in an indoor environment. The device includes passive sensors for measuring environmental physical conditions at known locations in the indoor environment and at an unknown locations in the indoor environment. A wearable computer is coupled to passive sensors. The computer is configured to construct a first statistical model of the environment according to the measured physical conditions at the known locations and a second statistical model of the environment according to the measured physical conditions at the unknown locations. Processing means of the computer determines a probability that the unknown locations correspond to the known locations by comparing the second statistical model to the first statistical model.

Abstract: A system for broadcasting GPS assistance data in a wireless communication network to mobile stations is disclosed herein. Each mobile station includes a transceiver operating in the wireless communication network and an integrated GPS receiver to make GPS positioning measurements. The system includes a GPS receiver for obtaining orbital modeling information for visible GPS satellites and DGPS correction data. A transceiver communicates with mobile stations in the wireless communication network. A broadcast controller is operatively associated with the GPS receiver and the transceiver for selectively establishing a direct point-to-point channel with select mobile stations for transferring the orbital modeling information and for periodically broadcasting the DGPS correction data on the wireless communication network to all mobile stations communicating in the wireless communication network.

Abstract: This is a technique using a fiber-optic, wideband array antenna beamformer having cascaded, chirped fiber gratings in a distributed architecture based upon the use of cascaded, fiber-optic, chirped Bragg gratings in a distributed architecture for use in wideband, time-steered array antennas. A wavelength tunable laser serves as a carrier for a microwave signal which is modulated upon it. The signal is corporately distributed to each feed of the array. Each feed then traverses a multi-port optical circulator and is reflected off a number of identical, chirped fiber gratings proportional to their position within the array. The signal is then demodulated and fed to the appropriate antenna element. All gratings are identical with the same length and dispersion (ps/nm). Time-steering is accomplished by tuning the laser wavelength such that the effective reflection point in an individual grating is changed due to the chirped nature of the grating.

Abstract: A GPS receiver for shortening the time for locking onto a satellite includes a detector having an oscillator and plural reception channels, a navigational-message-receiver for analysing the message demodulated at the detector from a signal transmitted by a GPS satellite, a position-determiner for acquiring information of the receiver's position, a satellite-selector for selecting a receivable GPS satellite, a stationary-satellite-receiver for receiving a signal from a stationary satellite and measuring an offset frequency of the oscillator. The satellite selector sets a scanning range on a center frequency for each channel, the scanning range being formed by adding the Doppler-shift frequency to the offset frequency of the oscillator, the offset frequency being measured by the stationary-satellite-receiver. The stationary-satellite-receiver always receives signals from the stationary satellite to measure the offset frequency of the oscillator while a main power source is turned off.

Abstract: In a satellite communication system (20), a method (50) and system of locating terrestrial-based user terminals (UTs). A UT (23) is located by a two-tier estimation procedure. Under this procedure, an initial estimate of the UT location is performed based on absolute signal propagation delay and Doppler shift measured from a communication link between a satellite and the UT. A second, refined estimate of the UT location is then performed based on the results of the initial estimate. The second estimate can be a function of the absolute propagation delay and absolute Doppler, as well as differential delay and differential Doppler measured from transmissions from two or more satellites (21-22) to the UT (23).

Abstract: A preferred embodiment permits the safe navigation of a channel or harbor by a ship. A preferred embodiment includes a ship-borne system having a first global positioning system (GPS) receiver and a second fixed reference station with a GPS receiver. Both GPS receivers have GPS signal receiving antennas. Earth orbiting satellites of the GPS maintain communication at both locations via the two receive antennas. A broadcast radio transmitter at the reference station transmits a received GPS signal to the ship-based GPS antenna for receipt by the ship's separate radio receiver and processing by a computer. Using known navigation chart information on the water depths within a body of water, channel or harbor, known marine surveyor data, including the phase center of the ship-borne GPS receive antenna, and the two separately received GPS signals, the ship's keel clearance referenced to a known chart datum is calculated at one second intervals.

Abstract: A method for position determination with the aid of GPS satellites, including reception processing of a GPS satellite signal L2 modulated by an encrypted code Y having a key not available from the GPS satellite, so as to assess a delay of the signal L2 with respect to the signal L1 and to deduce therefrom the magnitude of the ionospheric effect so as to take account thereof and improve the accuracy of the location finding.

Abstract: A method of tracking airborne substances including the steps of detecting the presence of one or more airborne substances and releasing a tracking balloon into the path of the one or more airborne substances, the tracking balloon having a transmission means and a global positioning means adapted to communicate the latitude and longitude coordinates of the tracking balloon whereby the latitude and longitude coordinates of the tracking balloon are representative of the latitude and longitude of the one or more airborne substances previously detected.