Abstract: System and methods are disclosed for passively determining the location of a moveable transmitter utilizing a pair of phase shifts at a receiver for extracting a direction vector from a receiver to the transmitter. In a preferred embodiment, a phase difference between the transmitter and receiver is extracted utilizing a noncoherent demodulator in the receiver. The receiver includes an antenna array with three antenna elements, which preferably are patch antenna elements spaced apart by one-half wavelength. Three receiver channels are preferably utilized for simultaneously processing the received signal from each of the three antenna elements. Multipath transmission paths for each of the three receiver channels are indexed so that comparisons of the same multipath component are made for each of the three receiver channels. The phase difference for each received signal is determined by comparing only the magnitudes of received and stored modulation signals to determine a winning modulation symbol.

Abstract: An intrusion detection system and method are provided that can utilize impulse radio technology to detect when an intruder has entered a protection zone. In addition, the intrusion detection system and method can utilize impulse radio technology to determine a location of the intruder within the protection zone and also track the movement of the intruder within the protection zone. Moreover, the intrusion detection system and method can utilize impulse radio technology to create a specially shaped protection zone before trying to detect when and where the intruder has penetrated and moved within the protection zone.

Abstract: A location system is disclosed for commercial wireless telecommunication infrastructures. The system is an end-to-end solution having one or more location centers for outputting requested locations of commercially available handsets or mobile stations (MS) based on, e.g., CDMA, AMPS, NAMPS or TDMA communication standards, for processing both local MS location requests and more global MS location requests via, e.g., Internet communication between a distributed network of location centers. The system uses a plurality of MS locating technologies including those based on: (1) two-way TOA and TDOA; (2) pattern recognition; (3) distributed antenna provisioning; and (4) supplemental information from various types of very low cost non-infrastructure base stations for communicating via a typical commercial wireless base station infrastructure or a public telephone switching network.

Abstract: Wireless network devices can obtain their geographical location by triangulating with access points that have precise time information. In response to a location prompt, a wireless device can send a transmission to multiple access points that are within its range. The different times at which the transmission is received at different access points can be collected and forwarded to a server, which can compute the location of the wireless device using triangulation techniques. The access points can calibrate their own time bases from time services received from global position satellites.

Abstract: The Precision Position Measurement System (PPMS) measures the location of the source of electromagnetic radiation in 3-D physical space to accuracies on the order of fractions of a wavelength using phase difference measurements among several receiving antennas, one of which is designated as the reference. All signal processing is done at the transmitter's RF frequency and in a single receiver with distributed RF signal amplification. Spatially distributed RF amplification is used to achieve sufficient signal strength for phase measurement without using up/down conversion receivers thereby eliminating sources of error due to local oscillator instability.

Abstract: A time division multiplexed reader to shared RF channel processor signal transport network for a geolocation system in which the number of readers is relatively small, allowing the use of only a single shared RF channel processor. The differential signal transport delays among respective segments of the network creates an inherent set of time division multiplexed time slots for the various readers, that allows the shared RF channel processor to receive and process the output of each reader in a known, independent time frame.

Abstract: A first signal and a second signal are detected. The first and second signals are transmitted according to a timing pattern. An arrival time is identified for the first and second signals. Based on the timing pattern and the estimated arrival times of the first and second signals, a set of parameters is derived that characterize a timing relationship between a first device (100) and a second device (200).

Abstract: A system and method is provided for determining the position of a transmitter/receiver device (13) arranged anywhere in a space in relation to at least two transmitter/receiver devices (11, 12) arranged at defined positions in the space with regard to each other. At least three transmitter/receiver devices (11, 12, 13), which each have an antenna device with a number of antenna units (20, 26, 27) distributed in a defined manner on a spherical surface (17) and a signal generating device, of which two transmitter/receiver devices (11, 12) are at least temporarily fixed in a local co-ordinate space (16). The other transmitter/receiver device (13) is movable relative to these devices.

Abstract: A source localising method comprises the steps of measuring the power received by a set of sensors and selecting N measurements from respective sensors, where N is an even number and at least four. N−1 different direct power ratios are constructed each derived from the N power measurements, with different numerators and denominators derived from respective halves of the measurements in each case. The construction of N−1 direct power ratios is facilitated by the use of a suitably constructed Hadamard matrix. Each direct power ratio may be converted with a logarithmic transformation into a linear combination of measured powers.

Abstract: A tool for augmenting and customizing business transaction processes uses the communication capability and functionality of a geolocation system to embed information associated with a transaction of a tagged object within the spread spectrum signals used to geolocate the object. This enables an ancillary transaction controller, separate from the geolocation system, to focus or target one or more transactions with respect to the tagged object, which may be an individual, such as a customer, patient, client, or the like of an institution in which the geolocation system is installed.

Abstract: System and methods are disclosed for passively determining the location of a moveable transmitter utilizing a pair of phase shifts at a receiver for extracting a direction vector from a receiver to the transmitter. In a preferred embodiment, a phase difference between the transmitter and receiver is extracted utilizing a noncoherent demodulator in the receiver. The receiver includes an antenna array with three antenna elements, which preferably are patch antenna elements spaced apart by one-half wavelength. Three receiver channels are preferably utilized for simultaneously processing the received signal from each of the three antenna elements. Multipath transmission paths for each of the three receiver channels are indexed so that comparisons of the same multipath component are made for each of the three receiver channels. The phase difference for each received signal is determined by comparing only the magnitudes of received and stored modulation signals to determine a winning modulation symbol.

Abstract: A multiple pass location processing method, for use in a wireless location system (WLS), comprises identifying a received transmission as requiring multiple pass location processing whereby the WLS produces a first, lower quality location estimate and then subsequently produces a second, higher quality location estimate. The WLS then produces the first location estimate and provides it to a first location application, and then produces the second location estimate. The second location estimate may be a more accurate estimate than the first location estimate and/or of a higher confidence than the first location estimate. This method is suitable, but not limited, for use in connection with locating a wireless transmitter involved in an emergency services call and routing the call to a call center.

Abstract: Apparatus for and method of locating a subject being monitored as to whereabouts. A beacon having a radio frequency transmitter and receiver is attached to the subject. At least three scanning platforms each having a radio receiver and transmitter and, optionally, an onboard microprocessor and an atomic clock, issue signals which will evoke response signals from the beacon. A central station having a microprocessor, radio receiver and transmitter, and preferably, a display or other output for annunciating location of the sought subject, manages the search. At least one scanning platform is a miniature, unmanned, remotely a piloted vehicle, preferably an aircraft, which passes over a predetermined search area. Response signals from the beacon, when received at a scanning platform, are processed to enable determination of location of the beacon and hence the sought subject by triangulation. Time and location data are acquired by interaction with the global positioning system by the scanning platforms.

Abstract: A cooperative tracking system designed to track multiple cooperative targets within a given field in real time with high precision and high update rate comprises a microwave transmitter and two receivers with each target being provided with one or more coded microwave transponders which enable calculation of both position, speed and in a preferred embodiment direction of movement of each target.

Abstract: A method is disclosed for estimating the location of a transmitter based on signals transmitted therefrom. The transmitted signals are received at a plurality of reception locations and are employed to compile data including a plurality of entries, where each entry includes a received signal level (RSL) of a received signal, a channel identification of the received signal, and position information corresponding to the respective reception location when the received signal was received. The entries are organized into groups according to channel identification, and, in each group, entries having the same position information are consolidated. Thereafter, for each entry, the distance DRT between the reception location and the transmitter is estimated, and the distance DRR between the reception location thereof and an adjacent reception location is also estimated.

Abstract: An imaging system (10) that includes a passive millimeter-wave camera (14)employing a focal plane array (60) of millimeter-wave integrated circuitry receivers (32). The camera (14) images a scene (58) that may include one or more beacons (12). The beacons (12) transmit millimeter-wave radiation signals (16) that are modulated by a modulator (24) so that the beacons (12) can be distinguished, and possibly provide communications in addition to beacon location. The receivers (32) in the camera (14) employ a demodulator (40) to demodulate the detected millimeter-wave signals from the scene (58). Therefore, not only does the camera (14) image the beacons (12) in the scene (58), but also can separate and decipher communications signals from the beacons (12).

Abstract: This invention relates to a method for calibrating a wireless location system (WLS) to enable the system to make highly accurate differential measurements such as time difference of arrival (TDOA) and frequency difference of arrival (FDOA). Calibration is accomplished by transmitting a signal from an unknown location and measuring at each of two receivers the parameter to be calibrated from that part of the received signal reflected or refracted from an object at a known location in the area. A differential measurement error is determined by comparing the expected difference in the parameter measurements with the actual difference in the parameter measurements. The expected difference is known, a priori, based on the locations of the receivers and the location of the object.

Abstract: Apparatus for and method of locating a subject being monitored as to whereabouts. A beacon having a radio frequency transmitter and receiver is attached to the subject. At least three scanning platforms each having a radio receiver and transmitter and, optionally, an onboard microprocessor and an atomic clock, issue signals which will evoke response signals from the beacon. A central station having a microprocessor, radio receiver and transmitter, and preferably, a display or other output for annunciating location of the sought subject, manages the search. At least one scanning platform is a miniature, unmanned, remotely piloted vehicle, preferably an aircraft, which passes over a predetermined search area. Response signals from the beacon, when received at a scanning platform, are processed to enable determination of location of the beacon and hence the sought subject by triangulation. Time and location data are acquired by interaction with the global positioning system by the scanning platforms.

Abstract: A system and method for performing real-time position detection and motion tracking of mobile communications devices moving about in a defined space comprised of a plurality of locales is provided. A plurality of access points are disposed about the space to provide an interface between mobile devices and a network having functionality and data available or accessible therefrom. Knowledge of adjacency of locales may be used to better determine the location of the mobile device as it transitions between locales and feedback may be provided to monitor the status and configuration of the access points.

Abstract: The invention relates to a method for detecting a home area in a mobile station, and to a mobile station realizing the invention. According to the invention the home area is detected in the mobile station by comparing (8) data received by the mobile station from the base stations of a cellular network with predetermined (1 to 6) home area data stored in the mobile station. The home area data is determined (1 to 6) based on preferably all of the following data: a) a mobile country code (MCC), b) a mobile network code (MNC), c) a location area code (LAC) and a related cell identity (CI) for all broadcasting channels (BCCH) which the base station is able to receive, d) received signal strengths (RSS) for all broadcasting channels BCCH, e) distances from all base stations (BTS) on the broadcasting channels BCCH, and f) timing advances (TA).

Abstract: This invention relates to a method for calibrating a wireless location system (WLS) to enable the system to make highly accurate differential measurements such as time difference of arrival (TDOA) and frequency difference of arrival (FDOA). Calibration is accomplished by transmitting a signal from an unknown location and measuring at each of two receivers the parameter to be calibrated from that part of the received signal reflected or refracted from an object at a known location in the area. A differential measurement error is determined by comparing the expected difference in the parameter measurements with the actual difference in the parameter measurements. The expected difference is known, a priori, based on the locations of the receivers and the location of the object.

Abstract: The present invention provides a method for the real-time location of a multiplicity of Mobile Units by correlating a commanded radio signal from the specific Mobile Units received by multiple fixed antennae. The Mobile Units are equipped with a transceiver that is activated by an encoded broadcast and responds with a burst transmission on a separate frequency that is received by several well-surveyed antennae at slightly different times due to the variable distance of the Mobile Units to the Fixed Receiver antennae. The location of a Mobile Unit is determined by resolving the burst transmission time delay differences from at least four fixed antennae to eliminate the common system unknowns.

Abstract: In a wireless location system, narrowband receivers are used in a mode, known as automatic synchronous or sequential tuning, in which the receivers are tuned sequentially and in unison to a plurality of predefined RF channels. Signal transmissions of interest in these channels are digitally recorded and used in location processing. A location record or report is generated to identify an estimated location of one or more wireless transmitters. The identity of the located transmitter(s) is determined by matching the location record to data indicating which wireless transmitters were in use at a time corresponding to the location record, and which cell sites and RF channels were used by each wireless transmitter. This method is especially suited for voice or traffic channel tracking of wireless mobile transmitters, such as cellular telephones.

Abstract: The phase difference between a known stable reference signal (11) and a known signal output by a wireless mobile communication device (5, 5B) is determined at several known locations (1-4, 1B-4B). The location of the wireless mobile communication device is then determined from the phase difference information. Also, the approximate location of a wireless mobile communication device (5A) can be estimated by transmitting a message from the device at a predetermined power level (71), and determining where among a plurality of predetermined locations (1A-4A) the transmitted message has been received.

Abstract: A passive ranging/tracking processing method provides information from passive sensors and associated tracking control devices and GPS/IMU integrated navigation system, so as to produce three dimensional position and velocity information of a target. The passive ranging/tracking processing method includes the procedure of producing two or more sets of direction measurements of a target with respect to a carrier, such as sets of elevation and azimuth angles, from two or more synchronized sets of passive sensors and associated tracking control devices, installed on different locations of the carrier, computing the range vector measurement of the target with respect to the carrier using the two or more sets of direction measurements, and filtering the range vector measurement to estimate the three-dimensional position and velocity information of the target.

Abstract: A radio handset includes: a signal receiver for receiving signals from a plurality of radio stations; a reception timing analyzer for analyzing reception timings of signals received by the signal reception means; a radio station selector for selecting radio stations to be used in a position calculation; and a position calculator for calculating a position of a signal reception point by using the reception timings of the signals from the selected radio stations. The radio station selector selects the radio stations to be used in the position calculation in such a manner that when reception timings of signals from two or more of the radio stations cannot be separated from one another, it is decided to exclude a signal from at least one of these radio stations.

Abstract: A ground-based, precision aircraft landing system provides CAT I precision approach and landing guidance. The aircraft elevation position is determined by measuring differential carrier phase and time-of-arrival of the aircraft ATCRBS transponder reply. The transponder reply is received at a plurality of sensor antenna locations where it is then conveyed to a sensor, demodulated and digitized. The data is transmitted to a central processor where calibration and multipath corrections are applied. Aircraft transponder diversity antenna switching is isolated from the jitter and colored noise of transponder reply multipath by correlating differential phase jumps measured between separate sensor antennas. An estimate of the diversity antenna separation is maintained by Kalman filter processing; the estimated separation is used to correct the differential phase measurement data of aircraft elevation.

Abstract: A bi-static radar configuration measures the time-of-flight of an RF burst using differentially-configured sampling receivers. A precise differential measurement is made by simultaneously sampling a reference signal line and a free-space time-of-flight RF burst signal using separate sampling receivers having common sample timing. Two alternative sample timing systems may be used with the sampling receivers: (1) a swept delay using a delay locked loop (DLL), or (2) two precision oscillators slightly offset in frequency from each other. The receiver outputs are processed into a PWM signal to indicate antenna-to-antenna time-of-flight range or to indicate material properties. Applications include robotics, safety, material thickness measurement, material dielectric constant measurement, such as for fuel or grain moisture measurement, and through-tank fill-level measurement.

Abstract: Methods and apparatus are disclosed for measuring position and motion of a “marker” antenna (14), disposed on a subject (12) at a physical location to be tracked. Relative distance of the marker antenna (14) from receiving antennas (18) is measured by phase differences of its microwave signals (40) at the receiving antennas (18) for at least two successive marker positions. Alternatively, actual distances (104, 106) are calculated by choosing a source position (102) and iterating the distances (104, 106) until the calculated phase differences match those measured. Four to six receiving antennas (18) are positioned at edges of a volume (16) where activity is conducted. Each received signal (40) is amplified and down-converted in a mixer (44). A single reference oscillator (46) feeds all the mixers (42) to preserve phase relationships of the received signals. Received signals (40) are digitized and presented to a multi-channel digital tuner (50).

Abstract: A method of locating a mobile telephone includes steps of receiving, transmitting, increasing and determining. In the receiving step, a first base station receives a call from a mobile telephone, the call including a dialed number and a TDMA signal. In the transmitting step, the base station transmits a control message to the mobile telephone when the dialed number meets a predetermined criterion, such as being 911. The control message instructs the mobile telephone to transmit the TDMA signal at a maximum power. In the increasing step, the mobile telephone increases the TDMA signal to maximum power in response to the control message. Then in the determining step, location information for the mobile telephone is determined based on at least one characteristic of the TDMA signal received at at least one of the first base station and other base stations.

Abstract: A system for correlating secondary surveillance radar (SSR) data and ACARS data which results in a real time correlation of data which are unique to the separate existing systems. More specifically, a method is provided to attach flight identification data from ACARS signals to real time SSR data from Mode S transponders. Aircraft Mode S addresses are decoded and then converted to aircraft registration numbers using an algorithm or lookup table. Registration numbers are then correlated with registration numbers from decoded ACARS signals. The result is a real-time system which may provide an aircraft's registration information, including registration number, owner, make, and model, as well as its current flight identification number, and ACARS messages. As part of an aircraft multilateration system, the system provides an independent air traffic control picture complete with aircraft position and identification by flight number without the use of active radar equipment.

Abstract: The present invention is a more accurate system for estimating the location of a mobile-telephone without significantly increasing the interference level for other mobile-telephones in the same or neighboring cells. In one embodiment, the present invention uses a plurality of location terminals deployed throughout a cell to increase the chances of detecting line-of-sight signals and the signal-to-noise ratio at the location terminals. In this embodiment, a wireless communication network transmits receive information to the plurality of location terminals instructing each of the location terminals to receive a signal from a particular mobile-telephone. Specifically, the location terminal is instructed to monitor a specific communication channel during a specific time interval.

Abstract: A method and apparatus for determining the location of a mobile unit within a cellular system. A synchronized signal at a common phase is generated at each base station in a system. The mobile unit transmits a signal tone. Each base station compares the phase of the signal tone to the common phase of the synchronized signal to produce a phase offset. A system controller compares the difference between the phase offset of a first base station and the phase offset of a second base station and determines the difference in distance between the first base station and the mobile unit and the second base station and said mobile unit defining a hyperbolic or linear curve of locations. The system controller compares the difference between the phase offset of the first base station and the phase offset of a third base station and determines the difference in distance between the first base station and the mobile unit and the third base station and said mobile unit defining a second hyperbolic curve of locations.

Abstract: A Wireless Location System includes signal collection systems and location processors for processing digital data provided by the signal collection systems. To determine the geographic location of a mobile wireless transmitter, time difference of arrival, or TDOA, data is determined with respect to a plurality of first signal collection system/antenna-second signal collection system/antenna baselines. A method for selecting baselines for use in location processing comprises calculating a number of parameters for each of the plurality of baselines, and including in a final location solution only those baselines meeting or exceeding predefined threshold criteria for each of the parameters.

Abstract: A system for determining the location of a mobile station in a cellular communications network, comprising a plurality of locator units fixedly positioned for tracking and measuring communications between a base station and a mobile station initiating an emergency communication, each locator unit comprising a receiving means for monitoring a control channel of the base station for detecting and receiving identifying information including an assigned voice channel associated with the particular mobile station initiating said emergency communication, a storage means for storing the identifying information associated with the to emergency communication, a controller means for tuning the receiving means to the assigned voice channel associated with the emergency communication for receiving voice and control channel data between the base station and the mobile station, a transmission means operable in a first mode responsive to the receiving means and the controller means for initiating a second communication to a

Abstract: A system for wind profiling comprises sondes for being borne through the atmosphere by balloons and transmitting signals enabling identifying the sondes, and received by receivers capable of determining the angle of arrival (AOA) of the signals from the sondes, so that they can be tracked. In the preferred embodiment, the signal transmitted by each sonde is a phase-shift-keyed (PSK) signal. The carrier phase difference as measured at two spaced antennas is measured to provide an accurate but ambiguous measure of the difference in distance of the path length between the sonde and receivers, and the symbol phase difference is employed to remove the ambiguity. The difference in path length is then used to determine AOA. Atmospheric data and the sonde identification are encoded using a psuedo-random sequence (PRS) of the PSK symbols.

Abstract: A digital television (DTV) receiver is provided with a sounder comprising a wideband transmitter and a plurality of wideband receivers having separately located receiving antennas, so that the sounder is, in effect, a bistatic radar system for any given channel, in order to characterize a significant nearby, indoor reflector. A microprocessor receives the timing information generated by the wideband transmitter impulses and the reflected impulse returns to each of the receiving antennas, and calculates a multipath model representing the three-dimensional location of a significant, nearby scatterer.

Abstract: The geolocation of a wireless terminal is determined by performing a time/frequency analysis on incoming signals received at a plurality of locations, where each incoming signal includes at least one multipath component of a signal transmitted by the wireless terminal during, for example, regular communications. The time/frequency analysis involves the analysis of the frequency components of the transmitted signal at given instants in time to identify the time-of-arrival of the multipath components of the incoming signal. The time-of-arrival identified for the line-of-sight component of the incoming signal at a plurality of locations can then be processed to determine the geolocation of the wireless terminal.

Abstract: A collision recovery method for use in a Wireless Location System includes receiving a transmission from a wireless transmitter at multiple signal collection systems and multiple antenna ports of each of the multiple signal collection systems. At each of the multiple signal collection systems, the transmission received at each antenna port is converted into a digital format, and digital data representative of the received transmission is stored. The transmission is then demodulated, and TDOA analysis is performed on the digital data from pairs of signal collection systems. The location of the wireless transmitter is determined using the TDOA data. The method further involves verifying that the RF data from each antenna port is from the wireless transmitter to be located, e.g., by demodulating a segment of the transmission received at each antenna port and verifying that at least a combination of the following fields is correct: MIN, MSID, TMSI, IMSI, and ESN.

Abstract: A method for determining the geolocation of an emitter using sensors located at a single or multiple platforms is disclosed. Generally, the method includes the steps of receiving a first measurement set relative to a first emitter, the first measurement set including angle of arrival, time difference of arrival and/or terrain height/altitude measurements, receiving a first location guess or estimate for the first emitter, and determining at least a second location estimate using at least one of a batch least squares analysis and a Kalman filter analysis.

Abstract: A radio unit for computer systems for receiving and/or presenting data information transmitted within a commercial broadcast band and methods of manufacturing and using the same. The radio unit comprises an integrated antenna system, a first radio receiver, and an interface system for removably connecting the radio unit to a computer system. The integrated antenna system includes a first set of windings, a second set of windings, and a ferrite core with a first region and a second region. To reduce parasitic capacitance among the windings, the first set of windings are wound substantially in a first direction about a circumference of the first region, and the second set of windings are wound substantially in a second direction, substantially opposite said first direction, about a circumference of the second region and are coupled with the first set of windings at a junction between the first region and the second region.

Abstract: An asset management radio location system uses time-of-arrival differentiation for random and repetitive spread spectrum, short duration transmissions from object-attached tags, to geolocate objects within a monitored environment. An object location processor is coupled to distributed tag transmission readers over signal transport paths having different transport delays, and carries out time-of-arrival differentiation of first-to-arrive transmissions from a tag to determine where its object is located. Geolocation errors associated with variations in parameters of the signal transport paths are effectively removed by installing one or more ‘reference’ tags, whose geolocations are precisely known. Using a background calibration routine that is exercised at a relatively low cycle rate, emissions from the reference tags are processed and coupled to the geolocation processor. The calculated geolocations of the reference tags are compared with their actual locations.

Abstract: The present invention relates to a device for measuring the movements of a moving object, especially in a hostile environment, starting from a predetermined initial position, comprising:

Abstract: Apparatus for determining the location of a subscriber unit (1) in a mobile telecommunications network, and particularly in a GSM cellular network, includes the provision of several receiver stations (4, 5, 6) positioned at separate known locations within each cell. Each of the receiver stations (4, 5, 6), which are synchronised by means of an on-board GPS receiver (10), measures the time of arrival of a message transmitted from the subscriber unit (1). The time of arrival measurements recorded by each receiver station (4, 5, 6) are then transmitted to a base transceiver station (2) for computation of the subscriber unit's location relative to the receiver stations. The apparatus can provide a reasonably accurate means for location with a low susceptibility to interference.

Abstract: There is described a system and method for locating, and optionally monitoring the status of, a mobile entity in a given area fitted with a radio beacon. In one embodiment, the system features a network of bi-directional radio beacons which transmit on the same frequency at random intervals. A method for processing and relaying unique message identifiers throughout the system is disclosed which allows the vicinity of the mobile entity to be determined from any beacon in the network.

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 call tag-based material replenishment system employs a tagged object radio location infrastructure of the type described in the U.S. Pat. No. 5,920,287. For each different part used by a lineside workstation an associated ‘call’ tag is placed at or near that workstation. To initiate replenishment of a part, a ‘call’ push-button on a call tag is operated. In response to the operation of the call button, an RF signal burst containing tag identity and status data is transmitted from the call tag. This information is recovered by a spatially distributed reader and processor subsystem for application to an asset management database. The database associates the call tag's identification data with a particular part, to enable a resource management operator to specify what component is to be accessed from storage and delivered to the requesting call tag's workstation.

Abstract: A method is provided of identifying position location of a transmitter device, such as a mobile or portable, in an inbound system. The inbound system includes free receivers all coupled, over appropriate radio frequency (RF) links, to a common reference receiver, the latter equipped with a high precision timebase master clock for receiver synchronization purposes. Rather than requiring each and every receiver to maintain a separate high-precision timebase to record position related timing signals for position location determination, in accordance with a preferred embodiment, the free receivers are configured to detect timing signals from the transmitter device, and without timestamping them, quickly forward them (in the form of a signal-received indication) after a fixed or otherwise known time delay to the reference receiver. The reference receiver, in turn, timestamps all signals from all free receivers according to its own master clock high precision timebase.

Abstract: An object tracking system for locating radio-tagged objects has a plurality tag transmission readers that detect tag transmissions, and generate time-of-arrival output signals representative of the time-of-arrival of first-to-arrive tag transmissions on the basis of clock signals generated by local clock generators at the tag reader sites. The tag reader sites may transmit time-of-arrival signals to an object location processor by way of a wireless local area network. Measurements made on transmissions from a fixed position reference tag are used to update a reader clock offset database employed by the processor to maintain the reader clocks effectively time aligned.

Abstract: A tool for augmenting and customizing business transaction processes uses the communication capability and functionality of a geolocation system to embed information associated with a transaction of a tagged object within the spread spectrum signals used to geolocate the object. This enables an ancillary transaction controller, separate from the geolocation system, to focus or target one or more transactions with respect to the tagged object, which may be an individual, such as a customer, patient, client, or the like of an institution in which the geolocation system is installed.