摘要:
A method of accurate determination of a fixed position using global positioning system uses pseudo-range output over a predetermined measurement period from a stand-alone GPS receiver located at the fixed position, the pseudo-range output being measured from an ensemble of spacevehicles at each time t over the measurement period, and historical ephemerides of the ensemble of space vehicles over the same measurement period to eliminate errors caused by selective availability. The historical ephemerides of the ensemble of space vehicles corresponding to each measurement time t are determined, and using the pseudo-range output and the historical ephemerides, a position solution at each time t is computed. The accurate position in earth-centered earth-fixed coordinates is then the average of all the position solutions at each time t over the measurement period.
摘要:
A direction finder is provided that can measure the incoming angles of plural incoming signals without spatially moving antenna elements and can be used in outdoor mobile communication environments. The direction finder also can shorten the measurement time. An array antenna comprises plural antenna elements arranged at regular intervals. The received signal components due to the mutual coupling between the antenna elements are removed by multiplying time series signal groups by the inverse matrix of a coupling coefficient matrix of the array antenna. The time series signal groups are obtained by modulating signals received with the array antenna. The covariance matrix of the received signal group can be subjected to a movement averaging process in terms of the Vandermonde format. The coupling coefficient matrix of the array antenna is obtained by normalizing the measurement result of an array element pattern containing a mutual coupling with a measurement result of an element pattern of a sole antenna element not containing a mutual coupling and then by expanding the normalized result in a Fourier series.
摘要:
A GPS receiver being able to realize reduction of power consumption in a tracking process includes: a receiving portion receiving a signal transmitted from a satellite; a correlation value calculation portion connected to the receiving portion generating a pseudo noise signal corresponding to the satellite and calculating a correlation value of a reception signal output from the receiving portion and the pseudo noise signal; a data demodulation device connected to the correlation value calculation portion demodulating data included in the reception signal based on the correlation value every predetermined cycle; a time period determination device connected to the correlation value calculation portion seeking a condition of the reception signal at reception based on the correlation value and determining a correlation value calculation period at the correlation value calculation portion according to the condition at the reception; and a process suspension control device connected to the time period determination device and the correlation value calculation portion obtaining a suspension period of an operation relating to the calculation of the correlation value at the correlation value calculation portion based on the predetermine cycle and the correlation value calculation period and suspending the operation relating to the calculation of the correlation value at the correlation value calculation portion for the suspension period.
摘要:
A GPS receiver having multiple GPS antennas. Also described is a method of tracking employing the GPS receiver and a communication transmitter. Also described is a garment having a GPS receiver and a GPS antenna and a communication antenna and a communication transmitter.
摘要:
A passive system for locating a distant source of radio frequency energy, for example a pulsed radar transmitter, from a portable platform such as a moving aircraft. The disclosed system is non ambiguous in locating ability by way of using time difference of arrival and time difference of arrival-rate processing of signals received from the distant source. This is in contrast with phase-based locating wherein location ambiguities are inherent. The disclosed system is supported by an included recalibration subsystem enabling practical maintenance of time difference of arrival system algorithm accuracy notwithstanding physical component and signal delay changes attributable to thermal or other environment effects. Maintenance of delay measurements accurate into the tens of picosecond range by this recalibration arrangement are employed to obtain usefully precise energy source locations. Mathematical equation-based disclosures of signal delay algorithms and their recalibration are included.
摘要:
A portable GPS receiver receives a signal from a GPS satellite by a GPS receiving means to measure a position and a speed of the own receiver. A traveling pitch detector detects a traveling pitch of a human body. A timer determines an operating period to intermittently operate reception from the GPS satellite. A stride calculator calculates, on the operating period, a traveling stride from received positioning data between two points and a pitch detected by the traveling pitch detector during obtaining the positioning data. A speed/distance calculator calculates, on the operating period, a traveling speed and a traveling distance from the stride determined by the stride calculator and the pitch detected by the traveling pitch detector.
摘要:
Carrier signal cycle slip errors occurring at a receiver in a satellite-based navigation system, such as NAVSTAR GPS, are detected. A continuous navigation signal is received from a satellite. Cycles of the carrier wave of the navigation signal are counted over a time &Dgr;t. The cycle count and the time &Dgr;t are used to compute a first velocity of the receiver along a vector between the receiver and the satellite. A second velocity of the receiver is received from an inertial reference unit associated with the receiver. A component of the second velocity along the vector to the satellite is computed. A difference between the first and second velocities is then computed and compared to predetermined value. If the difference exceeds the predetermined value, then a cycle slip error is indicated.
摘要:
A relative vehicle positioning system for a vehicle includes a GPS antenna adapted to receive satellite signals generated in response to relative vehicle positioning and generate therefrom a GPS signal. A Bluetooth radio is adapted to exchange bearing information with a second vehicle and generate therefrom a PVT signal. A GPS unit including a controller is adapted to receive the GPS signal and the PVT signal, the GPS unit is further adapted to generate therefrom a GPS-Bluetooth relative position signal.
摘要:
A handset upgrading system and method which permit cellular customers to upgrade their handset without visiting a local telephone store, providing a totally automated upgrade service, including application, delivery, and functional verification of new handsets. A requesting customer applies online for handset upgrade service and receives an application filing number from the system. Upon delivery of a new handset with an upgrade password, the customer calls up the system to request switching to the new handset, during which an ID code retrieving unit obtains from the network the identification code of the mobile handset that the customer is currently using. The request is verified by an upgrade request validation unit, based on the application filing number, upgrade password, reservation record, and identification code of the handset. If the request is validated, a switchover command unit directs a telephone exchange to change its setup. To ensure the result of upgrading, a mail and voice function verification units verify the mail and voice functions of the new handset, using a mail server and an interactive voice response (IVR) system, respectively.
摘要:
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.