Abstract: A portable location device for use in a location system, the device comprising a transmitter for transmitting ultra-wideband signals, a receiver for receiving non-ultra-wideband signals and a control unit coupled to the receiver for controlling the operation of the device in dependence on the received non-ultra-wideband signals.

Abstract: A system and method of managing collection and maintenance of performance data for a wireless communications network including collecting configuration data for the network, encoding the collected configuration data and storing the data, collecting a transmitted signal, measuring a parameter of the collected signal, and encoding and storing the parameter. These steps are repeated for additional configurations of the network. The transmitted signals are transmitted by a base station or a mobile device. Further, the transmitted signals are collected by a base station or a mobile device.

Abstract: Systems and methods for detection and geolocation of multiple emitters that are emitting RF signal energy on a common frequency, and that may be implemented to separate, geolocate, and/or determine the number of emitters (e.g., radio users) emitting on a common RF frequency. Real-time signal qualification processing may be employed to continuously monitor and collect incoming receiver tuner data for signal activity and ignore irrelevant noise data. Each set of data blocks from an emitter transmission signal may be defined as an emission cluster, and a set of time difference of arrival (TDOA)/frequency difference of arrival (FDOA) pairs may be computed for each emission cluster with each TDOA/FDOA pair yielding a geolocation result. A statistical qualification method may be used to produce a final geolocation answer from each set of emission cluster geolocation results, and a geolocation error ellipse computed for the final geolocation answer of each emission cluster.

Abstract: Iterative geolocation of a stationary RF emitter through the use of TDOA may include the use of a single portable geolocation (e.g., TDOA) sensor, a pair of portable geolocation sensors and three of more portable geolocation sensors. Adding portable geolocation sensors to the iterative process reduces the constraints on the signals to be located as well as providing a reduction in the number of iterations required to obtain improved location accuracy.

Abstract: A method for locating a UWB transmitter, without a previously-set reference, using at least one first set of at least three UWB searching transceivers, including first, second, and third transceivers. The method a) synchronizes the three UWB searching transceivers, arranged at three different points, and estimates the relative position of these three points; b) receives, by the three transceivers, signals transmitted by the transmitter to be located; and c) calculates the relative position, with respect to the three searching transceivers, of the transmitter to be located according to the time of travel of the signals, transmitted by the transmitter to be located, to the three searching transceivers.

Abstract: A method for performing Time Difference Of Arrival (TDOA) that eliminates the need for a common time base or clock calibration and a system for implementing the method. The method relies on a packet transmitted from a reference wireless device (first wireless device) with a known propagation delay between the first wireless device and a second device, which serves as a common reference point for all TDOA estimates. When a packet is received from a wireless device by the first wireless device and the second wireless device, the time difference of arrival is computed based on when the signal was received by the first device and the second device, using the known propagation delay to compensate for differences in clocks and frequencies between the first wireless device and the second wireless device.

Abstract: An architecture for a spread-spectrum transmitter-receiver system in an advanced tactical data link that allows the receiver to readily acquire and synchronize to a desired LPD signal. Signal acquisition is performed with a cyclic range search that uses multiple redundant known sequences mapped to a known message sequence in a highly repeated manner. By employing the invariance of the speed of light, and synchronicity between transmitter and receiver, the architecture can significantly reduce the computational complexity of the receiver. Additionally, the architecture enables ad hoc channel access, controlled latency, distance estimation, and distance-directed transmissions.

Abstract: A method and system for extensible positioning that uses a primary reference node at a known first position and a secondary reference node at a second position, where a range is measured between the secondary reference node and the primary reference node. The second position is determined based upon the first position and the measured range. A second range is measured between the secondary reference node and a non-fixed node. A third position corresponding to the non-fixed node is determined based upon the second position and the second range.

Abstract: A method and system for positioning mobile units using angle measurements taken by neighboring mobile units is disclosed. A selected mobile unit and mobile units in the vicinity of the selected mobile unit are selectively instructed to measure and report information related to the position of the selected mobile unit. The reported information is used to compute a position of the selected mobile unit.

Abstract: Instead of normalizing time reference of independent spatially-located clocks using a reference tag transmission from known location, the present invention uses an interarrival time interval between a pulse pair of UWB pulses as a timing metric. Thus, a method of synchronizing spatially-located clocks or normalizing time indications thereof comprises transmitting a UWB pulse pair, determining at first and second monitoring stations a respective count value indicative of a locally measured time interval between received pulse pairs, determining a ratio between clock counts of first and second monitoring stations, and utilizing the ratio to determine clock skew, e.g., a timing correction to be applied to respective local clocks of the monitoring stations.

Abstract: At least two receiver sets are provided. A data processor is in communication with the receiver sets, wherein the data processor tags position data and radio frequency emission data from the receiver sets. A data storage unit is in communication with the data processor and is at least capable of storing tagged data. A processing unit is capable of processing the tagged data. The processing unit defines a search grid within which to search for the source of the radio frequency emission. The processing unit motion compensates the tagged data separately for each point on the grid. The processing unit assigns a value to each grid point based on a phase coherence of the motion compensated data. The processing unit determines a location within the grid having a highest assigned value, thereby determining the source of the radio frequency emission.

Abstract: Multilateration techniques are used to provide accurate aircraft tracking data for aircraft on the ground and in the vicinity of an airport. From this data, aircraft noise and operations management may be enhanced. Aircraft noise may be calculated virtually using track data in real-time and provided to a user to determine noise violations. Tracking data may be used to control noise monitoring stations to gate out ambient noise. Aircraft emissions, both on the ground and in the air may be determined using tracking data. This and other data may be displayed in real time or generated in reports, and/or may be displayed on a website for viewing by airport operators and/or members of the public. The system may be readily installed in a compact package using a plurality of receivers and sensor packages located at shared wireless communication towers near an airport, and a central processing station located in or near the airport.

Abstract: A new human interface scheme compresses geographical information, latitudes and longitudes, into a 10 symbols of 36 radices number systems which are based on 36s. It is to simplify the conventional representation of the latitudes and longitudes into much easier to be remembered and accessed by human beings, 10 symbols of 36 radices numbers, “Universal Geo Numbers”. The 5 symbols here can give the accuracy for latitudes and longitudes down to 5 meters which should be enough to accommodate the specifications for most geographic navigation related systems (i.e. GPS/GLONASS) and navigation equipments in the consumer market. The apparatus includes all means that comprise latitude/longitude information into the compressed codes for interfacing between human and machines.

Abstract: The present invention provides a method of selecting receiving pairs from a set of at least three receivers that may be used to localize an emitter. This involves identifying the set of at least three receivers to be used to localize the emitter. An isochron may be developed for each receiver pair wherein each isochron has a finite width. The intersection of two isochrons creates an uncertainty parallelogram. When the intersection of two isochrones is substantially orthogonal or subtends a relatively large angle, uncertainty based on the intersection angle is minimized and uncertainty becomes primarily a function of isochron width. To determine acceptable or best receiver pairs to be used, the intersections of each isochron pair may be analyzed. The uncertainty parallelograms and intersection angles are compared for each pair of intersecting isochrons. Then, receiver pairs that produced the isochrons that result in a reduced or compact uncertainty parallelogram may be selected.

Abstract: A GPS tracker is disposed on launch hardware that separates from a spacecraft launch vehicle during ascent to orbit with the launch hardware having a suborbital trajectory from launch to impact while being tracked so as to track the launch hardware during suborbital flight, such as for tracking separated fuel stages, external tanks, external boosters, and payload fairings that return to earth.

Abstract: Groupings of receivers for determining a target location by a multilateration system are selected to give the best geometric dilution of precision result by eliminating the receiver that makes the greatest contribution to such dilution. In this way the groups to be used may be selected as appropriate for the location of the target in real time, avoiding the requirement to have a database holding the groupings to be used.

Abstract: According to typical practice of an inventive radar system, a switching device is capable of activating a receiver array one at a time so that when a receiver is activated the remaining receivers are inactivated. A switch control circuit is pre-programmed with control logic that is based on the counting of radio pulses that are emitted by a signal generator (for transmission by a transmitter). The control logic dictates, via the switching device, the rapid sequential cycling through of the arrayed receivers so that each receiver is activated for the same prescribed period of time, which corresponds to a pre-programmed number N of emitted radio pulses wherein N=[the number of frequencies in the wave table]×[the number of pulse integrations in the wave table]×[1 polarization or 2 polarizations]. Radio pulse input from the receivers is interleaved in a manner associable with individual receivers.

Abstract: An apparatus comprises a first sensor mounted on a first platform for sampling a first portion of a continuous waveform occurring in a time window and for producing a first signal sample, a second sensor mounted on a second platform for sampling a second portion of the continuous waveform occurring in the time window for producing a second signal sample, and a processor for determining time difference of arrival measurements and for applying a maximum likelihood estimation process to combine multiple time difference of arrival measurements between multiple pairs of platforms, to estimate the location of an emitter of the continuous waveform. A method performed by the apparatus is also provided.

Abstract: A method and apparatus for signal tracking utilizing a universal algorithm is disclosed. The method and apparatus generally include acquiring a signal measurement corresponding to a signal, forming a measurement matrix utilizing the acquired signal measurement, and applying the measurement matrix to a recursive filter to determine a geolocation of the signal. Such a configuration enables geolocations to be determined utilizing any signal measurement or combination of signal measurements to eliminate the need to rely on a particular static combination of signal measurements.

Abstract: A system (50) and method (300) for providing multipath error mitigation for real-time wireless tracking of an object (100) is disclosed herein. A plurality of sensor readings are obtained from a tag (60) attached to an object (100) within an indoor facility (70). A plurality of reading sets are generated and sorted by zones. A zone with the highest average reading is preferably selected and the location of the object (100) is calculated based on the selected zone readings. In this manner, faulty position readings are eliminated from the location calculation thereby allowing for more accurate tracking of the object (100) within the indoor facility (70).

Abstract: Multilateration techniques are used to provide accurate aircraft tracking data for aircraft on the ground and in the vicinity of an airport. From this data, aircraft noise and operations management may be enhanced. Aircraft noise may be calculated virtually using track data in real-time and provided to a user to determine noise violations. Tracking data may be used to control noise monitoring stations to gate out ambient noise. Aircraft emissions, both on the ground and in the air may be determined using tracking data. This and other data may be displayed in real time or generated in reports, and/or may be displayed on a website for viewing by airport operators and/or members of the public. The system may be readily installed in a compact package using a plurality of receivers and sensor packages located at shared wireless communication towers near an airport, and a central processing station located in or near the airport.

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 a one before trying to detect when and where the intruder has penetrated and moved within the protection zone.

Abstract: An antenna-assisted two-point positioning system for positioning a mobile device is disclosed. The antenna-assisted two-point positioning system comprises a first wireless communication module comprising first antennas, a second wireless communication module comprising second antennas, a storage module, and a processing module. The mobile device transmits a first signal strength to a first antenna for a first receive signal strength and a second signal strength to a second antenna for a second receive signal strength. The second wireless communication module and the first wireless communication module determine a first position and a second position corresponding to the mobile device. The storage module stores first antenna gain tables corresponding to the first antennas and second antenna gain tables corresponding to the second antennas.

Abstract: According to the invention, a subscriber to a first satellite radio service can be provided with an option to receive, over their current receiver unit, supplemental content, such as a particular show or channel, which is otherwise only available within a relevant jurisdiction as part of a subscription package to subscribers of one or more other satellite radio services. Thus, without purchasing a full subscription to another service, the subscriber of the first satellite radio service may arrange to receive supplemental content that is otherwise only available as part of a subscription package, such as a basic or general subscription package, to subscription holders of one or more other services. The invention also provides methods of broadcasting and methods of configuring dedicated and interoperable satellite radio receiver units so that the supplemental content can be received by a subscriber.

Abstract: Extending the activation and tracking capability of stolen vehicle recovery dedicated radio-frequency networks by the supplementary use of widely geographically provided cellular telephone-frequency band networks.

Abstract: Embodiments of the present invention provide a method and apparatus for signal tracking utilizing a universal algorithm. The method and apparatus generally include acquiring a signal measurement corresponding to a signal emitted from an emitter, forming a measurement matrix utilizing the acquired signal measurement, and applying the measurement matrix to a recursive filter to determine a velocity and/or geolocation of the signal emitter. Such a configuration enables velocities and geolocations to be determined utilizing any signal measurement or combination of signal measurements to eliminate the need to rely on a particular static combination of signal measurements.

Abstract: A novel beacon-based position location technique for efficient location discovery of untethered clients in packet networks is disclosed. The position location technique utilizes the time-difference-of-arrival (“TDOA”) of a first signal transmitted by a beacon of known location and a second signal transmitted by an untethered client. The TDOA of these two signals is measured locally by at least three non-collinear signal receivers. For each of the receivers, the TDOA is used to calculate a perceived distance to the client. A circle is then calculated for each receiver, centered on the receiver and having a radius equal to the perceived distance. At least two lines defined by points of intersection of the calculated circles are then calculated. The point of intersection of the lines represents the location of the client. To facilitate operation, the signal receivers may be arranged on vertices which define a convex polygon as viewed from above.

Abstract: Methods for determining the location of a stylus for a portable electronic device are disclosed. One embodiment provides a method for determining at a first time that a stylus was not returned to a stylus receiver of the portable electronic device and determining last usage information relating to a last usage of the stylus at a second, earlier time. The method may further include storing by the portable electronic device the determined last usage information and determining stylus location information based on the last usage information. The method may further include providing an indication of the stylus location information to a user. Stylus location information may include one or more of a physical location, a geographic location, a calendar event associated with a last usage, directions to a place of last usage, an application being used at last usage of the stylus, or a user identity.

Abstract: A method for determining the positions of targets by bistatic measurements using signals scattered by the targets is provided in which the velocities of the targets can also be determined. The range of the transmitters is selected so that a target at an arbitrary point can be measured, by scattering in the target, by at least four cooperating measuring facilities. First the targets are associated by calculating, in two independent ways, two sets of sums of distances between transmission points and targets and, respectively, targets and reception points. Subsequently, the two sums are sorted with respect to distance, compared with each other, and the sums that correspond with each other within a predetermined margin of error are stated to correspond to conceivable targets. The association of targets is improved and completed by corresponding calculations being carried out for Doppler velocities.

Abstract: A system and method automatically maps computer center rooms and locates data center components within computer centers. Radio triangulation is used to determine the locations and, optionally, orientation, of machines within a computer center.

Abstract: A location system comprising a plurality of base units for enabling the locating of a device by means of one or more location signals communicated between the device and the base units and signal processing equipment for: i. determining the location of the device in dependence on the manner in which the location signal(s) is/are received and ii. deriving calibration data for calibrating the system in dependence on the manner in which the location signal(s) is/are received.

Abstract: A system and method for monitoring topological changes in a defined area. A grid of sensors is arranged in the area, with known distances between them. The sensors communicate wirelessly with a host computer, which individually addresses each sensor to instruct that sensor to be in an interrogate mode or responder mode. When a sensor is in interrogate mode, it measures distance from a neighboring sensor using radar (continuous wave phase difference) measurements. When a sensor is in responder mode, it receives, delays, and returns a signal received from a neighboring sensor.

Abstract: A method for determining the location of an actuating device is described. The method includes receiving transmissions from the actuator utilizing a plurality of multiple channel receiving devices, determining a direction to the actuator based on the signals received, and retrieving position, orientation, and time information for the plurality of multiple channel receiving devices relating to each transmission received from the actuator. Also included in the method is triangulating the position of the actuator based on the position, orientation, time, and determined direction to the actuator for the plurality of multiple channel receiving devices. Systems that perform the above method are also described.

Abstract: A diversity system for positioning systems is disclosed, whereby a plurality of positioning signals, which are transmitted and/or are received from substantially the same location, are received and interpreted by an observing receiver. The observing receiver is configured to compare and then select substantially coherent positioning signals, and/or create a best-fit estimate of the measured positioning signals, such that accurate position measurements can be determined in multipath-affected environments.

Abstract: Instead of normalizing time reference of independent spatially-located clocks using a reference tag transmission from known location, the present invention uses an interarrival time interval between a pulse pair of UWB pulses as a timing metric. Thus, a method of synchronizing spatially-located clock or normalizing time indications thereof comprises transmitting a UWB pulse pair, determining at first and second monitoring stations a respective count value indicative of a locally measured time interval between received pulse pairs, determining a ratio between clock counts of first and second monitoring stations, and utilizing the ratio to determine clock skew, e.g., a timing correction to be applied to respective local clocks of the monitoring stations.

Abstract: Methods and apparatus operable to estimate the geolocation of a signal emitter. In some embodiments, the methods comprise acquiring collection data from a plurality of collector elements, computing a plurality of candidate geolocations from the acquired collection data, and applying a clustering analysis to the candidate geolocations to estimate the geolocation of the signal emitter.

Abstract: A current flowing from a circuit section into an integrated antenna flows through a coil. When a pseudo up-link signal is outputted from a VICS (light) signal processing circuit to check a connection state of an integrated antenna, since a large current flows through a transmitting element for optical beacons of the integrated antenna, a drop voltage of the coil becomes large. When the drop voltage of the coil is within a prescribed range because of divided voltages of resistors, the antenna detection circuit determines that the integrated antenna is normal. In this case, since a large current flows into the coil, a coil having small impedance is used.

Abstract: A method, apparatus, and computer-readable media for determining the position of a user terminal comprises receiving at the user terminal a broadcast television signal from a television signal transmitter; determining a first pseudo-range between the user terminal and the television signal transmitter based on a known component of the broadcast television signal; receiving at the user terminal a global positioning signal from a global positioning satellite; determining a second pseudo-range between the user terminal and the global positioning satellite based on the global positioning signal; and determining a position of the user terminal based on the first and second pseudo-ranges, a location of the television signal transmitter, and a location of the global positioning satellite.

Abstract: A radio geolocation system is described in which a plurality of moving platforms such as aircraft concurrently receive a signal from a remote transmitter and the geolocation of the transmitter is determined. At each platform every thirty seconds a plurality of samples of the received signal are taken over a one second period. The samples are digitized and a time and GPS location stamp are added to each sample. The digitized samples with time and location stamps from all platforms are transmitted to a central location and stored in covariance matrices, one matrix per one second sample period. The signal samples in each matrix are processed utilizing a unique algorithm to generate a data set which defines a correlation surface. The data from a plurality of data sets are summed together on a point by point basis and normalized to yield a summation data set which defines a summation correlation surface.

Abstract: A generalized framework is disclosed in which a wide variety of propagation models can be cast in a matrix-based format using arbitrary matrix coefficients. Casting propagation models in the matrix-based framework enables efficient computer implementation and calculation, ease of tuning, admissibility, and aggregating multiple propagation models into a single matrix-based model. Matrix-based propagation models based on transmitter-receiver azimuth orientation, transmitter antenna height, terrain elevation, and clutter are also disclosed. The propagation models can be used in conjunction with automated data acquisition from information sources such as topographic maps, clutter maps, etc.

Abstract: A method for enabling a system to enhance the accuracy of a location estimate modifies weights in a weight matrix associated with receiver station measurements in parallel with successive refinements of the location estimate. In a typical location estimation scenario, several receiving stations simultaneously derive measurements of a signal from the emitter. Any one of these measurements is in general some function of the emitter location and the receiving station location. The aggregate of these measurements is often in excess of the minimum number of measurements required to provide an estimate of the emitter location. Where such an excess exists, the method proceeds by modifying the weights associated with the measurements in parallel with successive refinements of the location estimate. The method can be implemented over various cellular protocols with a consistent and significant enhancement in the accuracy of location estimates.

Abstract: A method for enabling a system to enhance the accuracy of a location estimate modifies weights in a weight matrix associated with receiver station measurements in parallel with successive refinements of the location estimate. In a typical location estimation scenario, several receiving stations simultaneously derive measurements of a signal from the emitter. Any one of these measurements is in general some function of the emitter location and the receiving station location. The aggregate of these measurements is often in excess of the minimum number of measurements required to provide an estimate of the emitter location. Where such an excess exists, the method proceeds by modifying the weights associated with the measurements in parallel with successive refinements of the location estimate. The method can be implemented over various cellular protocols with a consistent and significant enhancement in the accuracy of location estimates.

Abstract: A novel beacon-based position location technique for efficient location discovery of untethered clients in packet networks is disclosed. The position location technique utilizes the time-difference-of-arrival (“TDOA”) of a first signal transmitted by a beacon of known location and a second signal transmitted by an untethered client. The TDOA of these two signals is measured locally by at least three non-collinear signal receivers. For each of the receivers, the TDOA is used to calculate a perceived distance to the client. A circle is then calculated for each receiver, centered on the receiver and having a radius equal to the perceived distance. At least two lines defined by points of intersection of the calculated circles are then calculated. The point of intersection of the lines represents the location of the client. To facilitate operation, the signal receivers may be arranged on vertices which define a convex polygon as viewed from above.

Abstract: Mobile LMUs can be used in a Wireless Location System to provide detection coverage in areas lacking adequate receiver coverage. The mobile LMUs can be used to detect the radio frequency (RF) transmissions from wireless handsets and devices over a period of time to permit determination of their location. The mobile LMU's time, position, and velocity is calculated and transmitted to a SMLC along with any transmissions received from wireless devices. The SMLC analyzes and resolves the Doppler component of the wireless device while compensating for the Doppler component of the mobile LMU. The position and velocity of the wireless device can be compared with real-time imagery taken by the mobile LMU platform to accurately determine the location of the wireless device. To enhance the mobile LMU's ability to detect a signal of interest, which may be very weak and/or corrupted by noise, a process may be employed whereby the low power mobile terminals' signals are received at receiving sites and stored in memory.

Abstract: The invention relates to a method of localization of one or more sources, said source or sources being in motion relative to a network of sensors, the method comprising a step of separation of the sources in order to identify the direction vectors associated with the response of the sensors to a source having a given, incidence, characterized in that it comprises at least the following steps: associating the direction vectors a1m . . . aKm obtained for the mth transmitter and respectively at the instants t1 . . . tK, localizing the mth transmitter from the associated vectors a1m . . . aKm.

Abstract: A system and method is disclosed which allows for the simultaneous capturing of signals at a plurality of diverse locations. In one embodiment, all transmissions received at each location are recorded for a period of time and after that period of time the recorded transmission is discarded. When a determination is made at any one of the locations that the recorded transmission includes a particular signal configuration, the time of receipt of such particular signal configuration is marked and the recorded transmission at that location is maintained so as to preserve the particular signal. When a location detects a particular signal a control signal is then sent to the other locations to cause the other locations to also “freeze” their recorded transmissions so that the desired particular signal can be retrieved from the recorded transmission. At least a portion of the captured signals at all locations are then communicated to a common point for processing.

Abstract: A system for tracking persons and other assets in a structure, having a multi-function tracking tag and a network of fixed RF receivers forming a gateway array. The location of the person being tracked is calculated by a computer using an algorithm that weights each separate signal according to the probability of its accuracy, thus using data with the least error. A preferred algorithm is shown in FIG. 2.

Abstract: Detecting a pulse of a signal includes receiving the signal and a light beam. The signal drives a spatial light modulator to modulate the light beam, where the complex amplitude of the modulated light beam is proportional to the signal current. The modulated light beam passes through an optical system and is detected by an optical detector array. A processor identifies a portion of the signal comprising the pulse.

Abstract: Apparatus for determining positional information relating to an object, comprising: means for receiving, comprising a plurality of receiving elements; detection means for detecting signals received at the receiving elements and for generating output signals representative of the received signals; and processing means operable to apply, for each receiving element, a process to the output signal generated from the signal received at that receiving element separately from any output signal generated from a signal received at any other receiving element, so as to obtain a respective value of a parameter representative of the signal received at that receiving element, the processing means being further operable to compare the values of the parameter thus obtained so as to, obtain positional information relating to the object.

Abstract: A method and apparatus for encoding information in a reference beacon signal for use in a time-difference-of-arrival/frequency-difference-of-arrival (TDOA/FDOA) geolocation system. Information is encoded in the reference beacon signal using variations in the times and frequencies of sequential reference signal transmissions. The encoded information may include an identifier associated with the transmitter of the reference beacon signal. A geolocation system receiving the reference beacon signal can thus differentiate it from non-cooperative target emissions as well as from other reference beacon signals.