Abstract: A wireless tracking system consists of a wireless target including a wireless communication system for transmitting a data packet over a communication path, and a locating station for determining a position of the target. The data packet transmitted from the target includes an identification code uniquely associated with the target. The locating station includes a configurable directional antenna, a communication interval processing system, a direction processing system, and a position processing system. The communication interval processing system is in communication with the directional antenna and determines the transmission interval of the transmitted data packet over the communication path. The direction processing system determines the transmission angle of the communication path, and is in communication with the directional antenna for controlling the configuration of the directional antenna so as to facilitate the determination of the transmission angle.

Abstract: A navigation satellite receiver method determines what navData is on-hand, what level of time uncertainty exists, and what position uncertainty there is for the receiver at turn-on. Indoor and outdoor search engines are used that can vary their search windows and dwell times to increase receiver sensitivity. Received signals are stored in several playback loops that can be operated in parallel to increase search sensitivity in the face of large uncertainties in time ad frequency, and still reduce the time-to-first-fix. Satellite acquisition can be achieved even when the navData is too weak to be read by requesting help from a server.

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 adaptive controller for an ESPAR antenna randomly perturbs a bias voltage vector V(n) composed of elements of bias voltage values Vm by a random vector R(n) generated by a random number generator, compares an objective function value J(n) of a cross correlation coefficient for a bias voltage vector V(n) before the perturbation with an objective function value J(n+1) of a cross correlation coefficient for a bias voltage vector V(n+1) after the perturbation, and selects and sets the bias voltage Vm corresponding to that when the cross correlation coefficient increases before and after the perturbation. Then the adaptive controller repeats the random perturbation and setting from the bias voltage of respective varactor diodes. This leads to that it is not necessary to provide a long training sequence signal, and the control process can be executed with learning so that a performance can be improved every iteration for search.

Abstract: A microelectromechanical system (MEMS) steerable electronically scanned lens array (ESA) antenna and method of frequency scanning are disclosed. The MEMS ESA antenna includes a MEMS E-plane steerable lens array and a MEMS H-plane steerable linear array. The MEMS E-plane steerable lens array includes first and second arrays of wide band radiating elements, and an array of MEMS E-plane phase shifter modules disposed between the first and second arrays of radiating elements. The MEMS H-plane steerable linear array includes a continuous transverse stub (CTS) feed array and an array of MEMS H-plane phase shifter modules at an input of the CTS feed array. The MEMS H-plane steerable linear array is disposed adjacent the first array of radiating elements of the MEMS E-plane steerable lens array for providing a planar wave front in the near field.

Abstract: A magnetic material exhibiting a high permeability at a high frequency range is materialized and a radio wave absorber exhibiting an excellent radio wave absorbing property by using such magnetic material is provided. The radio wave absorber comprises a mixed material containing a magnetic material grain, a resin material and a ceramic material or a low-melting-point metal material, in which the magnetic material grain is made into a disc shape is provided.

Abstract: A method of locating the source of an unknown signal of varying frequency received by receive antennas (16, 18) via relay satellites (12, 14) involves downconversion of received signals to a first intermediate frequency (IF) and band-limiting the downconverted signals. The band-limited signals are constrained to lie within a prearranged acquisition signal bandwidth by adjustment of local oscillator (LO) downconversion frequency to counteract frequency change in the unknown signal. Downconverted signals are offset in time relative to one another using trial values of differential time offset and their correlation is determined for each trial value to provide actual time offset. Compensation is provided for change in correlation phase angle, which results from signals being downconverted experiencing different LO frequencies during the time interval of the trial offset.

Abstract: An apparatus for providing GPS positioning information to a master computer and a plurality of slave computers from only one GPS receiver. The apparatus includes a circuit adapted to be coupled between the GPS receiver and the computers for providing each computer with a replica of a positioning information signal from the GPS receiver so that each computer receives all of the positioning information it would have received if it had been connected to its own GPS receiver. In addition, the apparatus includes a circuit adapted to be coupled between the GPS receiver and the computers for providing each computer with a replica of a synchronizing signal from the GPS receiver so that each computer receives the synchronizing signal it would have received if it had been connected to its own GPS receiver.

Abstract: An integrated position determination system and communication system is disclosed that includes an antenna and that includes position signal processing circuitry for determining position. The integrated position determination system and communication system also includes a radio for communicating with other position determination systems that is coupled to the position signal processing circuitry and a power supply. The integrated position determination system and communication system also includes a range pole to which the other components of the integrated position determination system and communication system are attached. The components of the integrated position determination system and communication system are located such that the system is both horizontally balanced and vertically balanced. More particularly, the integrated position determination system and communication system is horizontally balanced about the centerline of the range pole and is vertically balanced about a carrying point.

Abstract: A signal processing circuit for satellite communications signal includes a first one dimensional digital beam forming circuit for forming a beam signal in a first direction and a second one dimensional digital beam forming circuit for forming a beam in a second direction. A direction filtering circuit is coupled between the first one dimensional digital beam forming circuit and the second one dimensional digital beam forming circuit. The filtering circuit determining a communications signal direction of the satellite communications signal and tunes the filter to reduce a filter bandwidth and a frequency range of said beam signal prior to processing through the second one dimensional digital beam forming circuit.

Abstract: A mobile computer establishes a wireless communication session with a wireless access point of a computer network. The location of each wireless access point is known and obtainable either from a database on the network or from the access points themselves. The strengths of wireless signals passing between the mobile computer and multiple wireless access points of the network, including the access point with which the mobile computer has established the session are measured at multiple time intervals. The measurements may be taken at the mobile computer itself or at the wireless access points. The measured strength values are then weighted according to such factors as whether the mobile computer has already established a communication session with the access point from which the sample was taken, and how old the sample is. For each location, the weighted strength values obtained for access points in that location are summed.

Abstract: A method for distributing locating-relevant information includes providing a GPS position of a client to a server on a data network, and returning location-relevant information by the server based on the specified GPS position. Such location-relevant information include travel or tourist information (e.g., locations of tourist attractions, hotels, or restaurants). Commercial information such as discount coupons or advertising selected based on the Client's GPS position can also be provided. Financial or business transactions can be conducted using the GPS position for authentication or identification.

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: A GPS receiver utilizes measurements which span previous and current times, such as delta phase measurements, in a modified Kalman filter. The modified Kalman filter updates position information relating to both the current and the previous times, and s propagates the current position and velocity related information. Using both the current and the previous position related information in the filter in conjunction with delta phase measurements, essentially eliminates the effect of system dynamics from the system model, and a position difference can thus be formed that is directly observable by the phase difference measured between the previous and current time epochs.

Abstract: An antenna system for controlling multi beam independently and a base transceiver station using the same are disclosed. The multi beam controllable antenna system includes: at least one first dividing unit for dividing an input signal into a plurality of first divided signals; at least one first phase shifting unit for shifting the first divided signals and generating first phase-shifted signals; at least one first combining unit for combining the phase-shifted signals and generating a combined signal; at least one second dividing unit for dividing the combined signal into second divided signals; at least one second phase shifting unit for shifting the second divided signals and generating second phase-shifted signals; and a controlling unit for generating a control signal which controls horizontal and vertical half-power beam widths and tilting angles of the input signal independently by controlling the first and the second dividing unit and the first and the second phase shifting unit.

Abstract: Active high density multi-element antenna system [DS] for radiolocation of RF target radiation has a processor-controlled antenna array [CAA] having rings [R1, R2, R3] concentric about a central axis to define arcuate sectors Sn about the central axis, each ring having adjacent p.c. boards [PC1, PC2, PC3] with PIN diode-switched antenna elements within sectors. The rings provide three rings [E1, E2, E3] of discrete dipolar elements, defining electrically isolated antenna units [ASm], each radial to the central axis, of quasi-log-periodic configuration. Antenna units are switched in rotational sequence about the central axis to provide narrow beam signal selectivity, directionally rotatable about the central axis. An array control system [ACS] is operated, as under microprocessor control [34], by a host system [HS] to cause RF scanning. PIN diode switching is used on printed circuit boards within the array.

Abstract: An antenna having a tiled architecture with overlapping subarray in two dimensions is disclosed. Each tile has two orthogonal ports and there is no physical interconnection between adjacent tiles. The outputs are coupled to individual receivers. The outputs of ports from n adjacent tiles are digitally combined to form an overlapping subarray.

Abstract: A tracking system uses a miniaturized geographic position determination and communications module, preferably in the form of a thin capsule, enabling the enclosure to be hidden in very small spaces, including personal concealment. Electronic circuitry and a thin, rechargeable battery are contained within the enclosure, the circuitry including a global positioning satellite receiver, a communications transceiver, and a controller. The controller causes the global positioning satellite receiver to receive and decode a signal relating to the geographic position of the module; cause the communications transmitter to communicate the geographic position information to a remote location; and disable the global positioning satellite receiver and communications transceiver when not in use so as to conserve power.

Abstract: A method and computer program to configure feeds on a satellite (300, 310, 320) to provide for redundant coverage when a satellite (300, 310, 320) fails. Further, this method and computer program can enable the switching of feeds from commands from a ground station (30) to activate certain feeds and deactivate other feeds when demand for service changes. In addition, this method and computer program allow for repositioning of satellites so that when one satellite fails another satellite may take over its area of coverage by switching active feeds without the need for placing another satellite in orbit.

Abstract: A position information acquiring apparatus for receiving an electric wave and for on the basis of the received signal, acquiring the position information exhibiting the position where the product is kept to record successively the position information thus acquired is packed together with an objective matter of conveyance in a package box and then is operated in the state of being able to be moved to receive an electric wave signal radiated from the GPS satellite group to acquire successively the position information. On the basis of the position information, a map of a part corresponding to the position information is retrieved from map information which is previously obtained to carry out an output for showing visibly the resultant partial map and a symbol with which the position contained in a position history information is shown on the map.