Abstract: Embodiments provide systems and methods for determining the geolocation of an emitter on earth. A solution is obtained from two TDOA measurements that need not be acquired at the same time. A solution is obtained from a TDOA measurement and an FDOA measurement that need not be acquired at the same time and need not be coming from the same satellite pair. A location of an emitter can be determined from minimizing a cost function of the weighted combination of the six solutions derived from the two TDOA measurements and the two FDOA measurements, where the weight of each solution in the combination is determined based on the intersection angle of the two curves that define the possible locations of the emitter based on the TDOA and/or FDOA measurements.

Abstract: A method and system for selecting and connecting to an access point in a wireless network of devices, such as a Bluetooth network. Initially, an initiator device is preconfigured with a list of available access point addresses. The initiator device broadcasts an inquiry message that is received by available wireless devices which, in turn, respond with their respective addresses, occupancy level and device classification. The initiator device compares the respondent addresses with the preconfigured access point addresses and connects to a match, thus terminating the inquiry, provided certain fitness functions are satisfied. The fitness functions might include such considerations as occupancy rate, device classification, signal strength, or physical distance of separation. The list of addresses on the initiator device is updated automatically upon connecting with a network server whenever a new device is added or an old one removed from the network server's access point address list.

Abstract: Propagation time for a target signal path is determined by detecting and processing a plurality of unknown signals received at two locations. A third location is established, such that the propagation time between the third location and one of the two locations is known, and the signal path between the third location and the other of the two locations is the target signal path. The two locations are monitored for any signals that may be detected. Signals received at the two locations are processed to determine which signals have a common source, and of the signals having a common source, the signal having the greatest delay between times of reception at the two locations is selected. The selected signal is used to determine the propagation time between the two locations.

Abstract: A method and a device for determining the changing position of a mobile transmitter in a three-dimensional space is proposed in which transmitted signals are issued at a pre-determined frequency from a mobile transmitter, wherein a plurality of receivers receive said transmitted signals. An evaluation device evaluates the received signals for generating correlation curves between the transmitted and the received signals. From the curves of magnitude versus time, TOA values are determined, and from curves in the complex plane, phase values are determined using the time information from the TOA values. The position of the mobile transmitter is calculated as a function of TOA values and of phase or phase difference values.

Abstract: A system and method for estimating the range between two devices performs two or more ranging estimates with subsequent estimates performed using a clock that is offset in phase with respect to a prior estimate. The subsequent estimate allows estimate uncertainties due to a finite clock resolution to be reduced and can yield a range estimate with a higher degree of confidence. In one embodiment, these additional ranging estimates are performed at n/N (for n=1, . . . N?1, with N>1 and a positive integer) clock-period offset introduced in the device. The clock-period offset can be implemented using a number of approaches, and the effect of clock drift in the devices due to relative clock-frequency offset can also be determined. To eliminate the bias due to clock-frequency offset, a system and method to estimate the clock-frequency offset is also presented.

Abstract: Space-time solutions are determined by exchanging pings among nodes in a network. Each ping includes a current space-time state of the transmitting node, which includes the transmitting node's currently estimated location and corrected time (as a count stamp). A particular node in the network receives pings from the other nodes in the network and uses the data in the received pings to estimate its own current position and to correct its own free-running clock relative to a common system time. As a service to the network, the particular node then transmits its corrected time (as a count stamp) and estimated position to the other nodes. In some embodiments, the space-time solutions discussed herein are used as backup to other navigation systems, such as the Automatic Dependent Surveillance-Broadcast (ADS-B) system.

Abstract: A method of associating a universal time with time of arrival information of an identified component of a signal at a terminal of a radio positioning system is disclosed. In the method a marker signal with an associated universal time tag is obtained from a timing device (or the marker signal is obtained from an independent oscillator and a universal time tag assigned to the marker signal), and the time or phase relationship between the marker signal (or between the time of arrival information of said identified component respectively) and the oscillator is measured. The time of arrival information of said identified component relative to the oscillator is determined and the universal time corresponding to the time of arrival information of said identified component is calculated from said universal time tag and said measured time or phase relationship, before the calculated universal time is associated with said time of arrival information.

Abstract: A method for validating received positional data in vehicle surveillance applications wherein vehicles transmit positional data indicating their own position to surrounding vehicles. A a radio direction finding antenna arrangement of a receiving unit receives a signal carrying positional data indicating an alleged position of a vehicle, transmitted from a radio source. The bearing from the receiving unit to the radio source is estimated utilizing the radio direction finding antenna arrangement and the received signal. The distance between the receiving unit and the radio source is estimated based on the time of flight for a signal travelling there between at known speed. An estimated position of the radio source is calculated based on the estimated bearing and the estimated distance. A deviation value indicating the deviation/coincidence between the alleged position of a vehicle is determined according to the received positional data and the estimated position of the radio source.

Abstract: An Aided Location Communication System (“ALCS”) is described that may include a geolocation server and a wireless communication device having a GPS section where the GPS receiver section is capable of being selectively switched between a standalone mode and at least one other mode for determining a geolocation of the wireless communications device. An Aided Location Communication Device (“ALCD”) is also described. The ALCD includes a position-determination section having a GPS receiver and a communication section where the position-determination section is selectively switchable between a GPS-standalone mode and at least one other mode for determining a geolocation of the ALCD.

Abstract: Propagation time for a target signal path is determined by detecting and processing a plurality of unknown signals received at two locations. A third location is established, such that the propagation time between the third location and one of the two locations is known, and the signal path between the third location and the other of the two locations is the target signal path. The two locations are monitored for any signals that may be detected. Signals received at the two locations are processed to determine which signals have a common source, and of the signals having a common source, the signal having the greatest delay between times of reception at the two locations is selected. The selected signal is used to determine the propagation time between the two locations.

Abstract: A method for validating positional data in vehicle surveillance applications wherein vehicles transmit positional data indicating their own position to surrounding vehicles using a data link over which a transmission is initiated at a given transmission point in time that is known by all users of the data link. A signal transmitted from a radio source over the data link is received at a receiving unit. The signal carries positional data indicating an alleged position of a vehicle. The distance between the receiving unit and the radio source is estimated based on the time of flight and the propagation velocity of the received signal. The time of flight is determined based on the time elapsed from the transmission point in time of the signal to the time of reception of at least a first part of the signal. A deviation value is determined.

Abstract: Method and system for locating one or more transmitters in the potential presence of obstacles in a network comprising a first receiving station A and a second receiving station B that is asynchronous with A. The method includes the identification of a reference transmitter through an estimation of its direction of arrival AOA-TDOA pair (?ref,??ref) on the basis of the knowledge of the positions of the reference transmitter and of stations A and B, an estimation of the direction of arrival of the transmitter or transmitters and of the reflectors (or estimation of the AOA) on station A, and the correction of the errors of asynchronism between station A and station B by using the reference transmitter and the location of the various transmitters on the basis of each pair (AOAi, TDOAi).

Abstract: A system for locating a client in a wireless network. The system includes at least three access points. Each access point is adapted to wirelessly communicate with a client having a location using packeted data, be placed in wired data communication within a selected data network; and to share a common precise time reference using the selected data network. The system further includes a switch adapted to translate the relative position of the access points based on a shared common precise time reference and to calculate the location of the client based on a transmission from the client.

Abstract: Systems and methods are presented for passive location of transmitters in which two or more receivers time stamp received signals from target transmitters and the time stamped data for each target signal of interest is isolated to identify a peak power time of arrival for the signal at each transmitter from which differential scan observation values are derived, and for each signal of interest a line of position curve is computed based on the differential scan observation value and corresponding receiver locations, and for each signal of interest an estimated target transmitter location is determined based on an intersection of two corresponding line of position curves.

Abstract: By partially serializing the transmission of a sequence keyed UWB symbol (FIG. 2), the number of parallel receiver branches required to receive such a transmission is reduced. The reduced number of receiver paths are re-used during the reception of each of the partially serialized portions of a UWB symbol, and the local oscillator (312, 332, 334, 336) output frequencies are changed for reception of each of those portions. Reducing the number of parallel receiver paths advantageously reduces the amount of power consumed by such a receiver. Similarly, the amount of area required to implement such a receiver in an integrated circuit is advantageously reduced. In a further aspect of the present invention, a synchronization sequence uses less than the complete set of frequency bands (402-408) available for transmission of a UWB symbol.

Abstract: In a multilateration system receivers are grouped into two groups. The first group is used to determine a position of a signal source, for example, an aircraft equipped with a SAR transponder. From the determined position, predicted time of arrival values are produced for the second group receivers. These are compared with the actual time of arrival values for the signals arriving at the second group receivers. A difference is determined and then the variation of that difference is determined as the aircraft travels in its track. The groupings are then varied and further variations determined. When the minimum variation is determined an alert is given that the second group has a receiver which is operating with a larger than desirable group time delay.

Abstract: In a network-based Wireless Location System (WLS), geographically distributed Location Measurement Units (LMUs) must be able to detect and use reverse channel (mobile to network) signals across multiple BTS coverage areas. By using Matched Replica correlation processing with the local and reference signals subdivided into discrete segments prior to correlation, the effects of mobile clock drift and Doppler shifts can be mitigated allowing for increased processing gain.

Abstract: A wireless positioning method of a receiver is provided. Signals are received from a plurality of transmitters, propagation taps of the plurality of transmitters received from the plurality of transmitters are determined, respectively, the distance between the receiver and each of the transmitters is calculated, respectively, the weight of each of the transmitters is calculated by using each of the propagation delay tap, the distance is adjusted by using the weight of each of the transmitters, and an area, in which circles away by the adjusted distances between the receiver and each of the transmitters on the basis of each of the transmitters overlap with each other, is estimated as the location of the receiver. Thus, an error of wireless positioning according to a propagation environment can be reduced.

Abstract: A TDOA (time difference of arrival) location system, in which mobile wireless devices broadcast wireless signals which are received by two or more transceivers deployed in the vicinity of the mobile wireless device. Each transceiver measures the TOA (time of arrival) of the received broadcasted signal and reports the TOA to a central server. The central server then calculates the mobile device position using multi-lateration of TDOA values. The system uses fiber optic links between the antennas and the transceivers deployed in the location area to provide unique advantages that couldn't be achieved using RF coaxial cables.

Abstract: Methods and apparatus related to peer to peer communication networks are described. An active connection list is maintained by a wireless communications device supporting peer to peer communications. In various embodiments, the active connection identifier list being maintained is in addition to a list of discovered peers in the local vicinity. Paging signaling, e.g., peer to peer paging signaling, is used to establish active connections. Air link peer to peer traffic resources include traffic control resources and traffic data resources. A wireless communications device seeking to transmit on a traffic data resource transmits a traffic request signal on a traffic control resource. An active connection identifier is, in some embodiments, associated with a particular subset of traffic control resources. Thus, a wireless communications device monitors the portion or portions of the traffic control resource corresponding to its active connections for traffic request signals, but need not monitor other portions.

Abstract: A method and apparatus are disclosed for determining the position, or change in the position, of a mobile terminal. The terminal has a receiver for receiving the signals from one or more transmission sources at unknown positions and an independent positioning device able to find, when operative, the position of the mobile terminal. The method uses the independent positioning device to measure the position of the mobile terminal at one or more first locations. A respective first set of time or phase offset values of signals received from the transmission sources relative to each other or to a reference in the mobile terminal is measured in the mobile terminal, at each first location.

Abstract: A method for the detection of an object by the TDOA principle is provided. The object transmits a signal, which is received by a plurality of stations having known positions. The stations' clocks can have different unknown time delays in relation to each other. An additional stationary reference station having a known position relative to the stations and transmitting a signal that is received by the stations is provided. An unknown transmission delay can be generated between the emission of the signal from the object and the emission of the signal from the reference station. For each station the difference in travel time between receipt of the signal from the object and the signal from the reference station and the difference of the travel time differences between the stations are determined. Mathematical algorithms for determining the location are performed.

Abstract: A six-degree-of-freedom (6DOF) tracking system adapts aspects of Ultra-Wideband (UWB) measurement and microelectromechanical systems (MEMS) inertial measurements within a unique tightly coupled fusion algorithm to accurately and efficiently measure an object's position as well as orientation. The principle of operation of the system protects against the negative effects of multipath phenomenon and non-line-of-sight (NLOS) conditions, allowing a more robust position and orientation tracking system.

Abstract: A system supporting data retrieval from a plurality of wireless sensor nodes is defined. The system includes the plurality of wireless sensor nodes and a data retrieval device. The plurality of wireless sensor nodes include a transceiver receiving a first signal and transmitting a second signal. The second signal includes a sensed datum or an encoded statistic based on the sensed datum identified at the plurality of wireless sensor nodes. The data retrieval device includes a plurality of antennas transmitting the first signal toward the plurality of wireless sensor nodes and receiving the second signal from the plurality of wireless sensor nodes, and a processor coupled to receive the received second signal from the plurality of antennas, the processor defining a virtual receive signal from the received second signal for the plurality of antennas and processing the defined virtual receive signal to determine the identified sensed datum.

Abstract: A method for determining position and orientation of a rotating wing aircraft (e.g. helicopter) with respect to a ground station includes transmitting an electromagnetic signal from the aircraft. The signal includes a plurality of electromagnetic signals, each signal having a different selected frequency. The signal is detected at an array of sensors disposed on the ground surface in a selected pattern. The array includes at least one reference sensor and at least three spaced apart time difference determination sensors. A difference in arrival time of the signals between the reference sensor and each of the time difference determination sensors is determined and a spatial position of the aircraft is determined from the time differences.

Abstract: A method for locating sources emitting radio signals comprises arranging at least one first pair and one second pair of receiving antennae; arranging at least one additional receiving antenna; synchronizing all the antennae; acquiring with at least three antennae and/or at least two pairs of antennae, radio signals emitted by the source; digitally processing with each antenna, the signal received and generating a short report; sending with each antenna, the track report to a central processing unit; processing the track reports to form a global track file; sending to the antennae with the central processing unit, a suitable command for collecting data; digitally processing with each antenna, the signal received from the specific source and generating and storing a pulse report; sending the pulse reports to the central processing unit; calculating the TDOA for each signal; selecting and applying the procedure for identifying the coordinates of the transmitting antenna.

Abstract: A transmitter of a platform is arranged to generate a transmission pulse, which is transmitted to a receiver of another platform and is also arranged to couple its transmission pulse to a digital receiver associated with its platform via an attenuator and a coupler. Another platform performs a similar task. Each digital receiver determines the time separation between its transmission pulse and a received pulse from the other platform. The determined time separation information is shared with the other platform, and each digital receiver then determines a time offset between the time at its platform and the other platform.

Abstract: A method and apparatus for estimating the position of a mobile device in a multi-path environment. In one example, the method includes receiving a plurality of reference signals from a corresponding plurality of reference devices, for each reference signal, calculating expected time delay boundaries, for each reference signal, estimating a range between the device and the corresponding reference device based on a measured time delay of the reference signal falling within calculated time delay boundaries to produce a plurality of range estimates, and filtering the plurality of range estimates to generate a composite estimate of the position of the device.

Abstract: A positioning and ranging system includes a transmitter transmits a plurality of impulses; and a receiver receives the impulses; the receiver includes an initial detection unit records a sensing time of a first impulse among a plurality of impulses transmitted by the transmitter; a sensing margin detection unit for detecting a sensing margin being a difference between a field intensity of the first impulse and a reception limit field intensity of the receiver; a correction unit identifies a sensing error differential time based on a given relationship between the sensing margin and the sensing error differential time, and corrects the sensing time detected by the initial detection unit using the identified sensing error differential time; the system measures a distance between the transmitter and the receiver and a position of the transmitter based on a time the transmitter transmits the first impulse and a time the receiver receives the impulse.

Abstract: A method determines an optimum bandwidth that minimizes ranging error in a geolocation application. The method ensures that an optimum bandwidth is selected under all channel conditions (i.e., both line-of-sight (LOS) and non-LOS (NLOS) conditions). Additionally, the method is generic and system-independent, such that it is applicable to both coherent receivers (e.g., match filter (MF) based receivers), non-coherent receivers (e.g., energy detector (ED) based receivers) and any types of time-of-arrival (TOA) estimators (e.g., whether peak-detection or threshold-based TOA estimator), regardless of the signal-to-noise ratios (SNRs) under consideration.

Abstract: A system and method for estimating the range between two devices performs two or more ranging estimates with subsequent estimates performed using a clock that is offset in phase with respect to a prior estimate. The subsequent estimate allows estimate uncertainties due to a finite clock resolution to be reduced and can yield a range estimate with a higher degree of confidence. In one embodiment, these additional ranging estimates are performed at n/N (for n=1, . . . N?1, with N>1 and a positive integer) clock-period offset introduced in the device. The clock-period offset can be implemented using a number of approaches, and the effect of clock drift in the devices due to relative clock-frequency offset can also be determined. To eliminate the bias due to clock-frequency offset, a system and method to estimate the clock-frequency offset is also presented.

Abstract: A method of determining the location of a mobile device is provided. The method receives a signal with a known radio transmission pattern at the mobile device from each of several transmitting devices. The method correlates each received signal with a corresponding signal that has a same known radio transmission pattern to determine the time the signal traveled between the corresponding transmitting device and the mobile device. The method determines the location of the mobile device based on the time the signal travelled between the corresponding transmitting device and the mobile device. In some embodiments, determining the location of the mobile device does not require calculating a distance between the mobile device and any of the transmitting devices. In some embodiments determining the location of the mobile device includes solving a function that is dependent on the time the signals traveled between each corresponding transmitting device and the mobile device.

Abstract: A method estimates a delay in a time of arrival (TOA) of a transmitted signal by receiving the transmitted signal at multiple antennas via corresponding channels. Each received signal is correlated with the transmitted signal to obtain estimated channel coefficients and an estimated TOA. A variance of noise is also obtained for each received signal. A weight is determined for each received signal by dividing the channel coefficients by the variance of the noise. The weights are summed, and each weight is multiplied by the estimated TOA to produce a weighted estimated TOA, which are also summed. The summed weighted estimated TOA are divided by the summed weights to determine a final TOA estimate with respect to the transmitted signal.

Abstract: A method for testing each one of a plurality of receiving sites operative in a time difference of arrival geo-location system. The method comprises determining a theoretical time of arrival of a test message at each receiving site assuming the test message was transmitted from a test message transmitting antenna at a known location; determining a measured time of arrival of the test message at each receiving site, the test message transmitted from the test message transmitting antenna; determining a true time of arrival of the test message at each receiving site, the true time of arrival comprising the measured time of arrival less a start time of the test message; determining a difference between the theoretical and the true times of arrival for each receiving site, wherein the difference for each receiving site is indicative of a health of the receiving site.

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: This invention provides a novel high-accuracy indoor ranging device that uses ultra-wideband (UWB) RF pulsing with low-power and low-cost electronics. A unique of the present invention is that it exploits multiple measurements in time and space for very accurate ranging. The wideband radio signals utilized herein are particularly suited to ranging in harsh RF environments because they allow signal reconstruction in spite of multipath propagation distortion. Furthermore, the ranging and positioning techniques discussed herein directly address many of the known technical challenges encountered in UWB localization regarding synchronization and sampling. In the method developed, noisy, corrupted signals can be recovered by repeating range measurements across a channel, and the distance measurements are combined from many locations surrounding the target in a way that minimizes the range biases associated to indirect flight paths and through-wall propagation delays.

Abstract: A system and method establishes the time of flight and thereby distance between two transceivers on various media, including but not limited to vacuum, air, electrical wire, optical fiber; using carrier waves sent from one or more transmitters or transceivers to one or more receivers or transceivers. Carriers are arranged to allow the extraction of channel information and maintain acceptable peak to average ratios in an OFDM system.

Abstract: Systems and methods are disclosed associated with processing origin/location information of a source or event. In one exemplary implementation, there is provided a method of performing improved three-dimensional source location processing including constraint of location solutions to a two-dimensional plane. Moreover, the method includes obtaining a plane of constraint characterized as a plane in which the source is likely to occur, providing one or more virtual sensing elements each characterized as being located on a first side of the plane of constraint in a mirror image/symmetrical position across from a corresponding actual sensing element on an opposite side of the plane, and constraining possible origin locations to be located in the plane of constraint. Other exemplary implementations may include determining the origin location as a function of positions of the sensing elements and the virtual sensing elements as well as time-of-arrival and/or angle-of-arrival information.

Abstract: In a geolocation system for determining a geolocation of a target emitter, a method for determining the geolocation.

Abstract: Mobile terminals 201 to 203 measure strength of the received signal from plurality of base station antennas 101 to 105 and transmits it to network system 300. Network system 300 determines proximity state between plurality of base station antennas 101 to 105 based on the strength of the received signal from plurality of base station antennas 101 to 105 transmitted from mobile terminals 201 to 203. From that determination, the base station antennas proximity state matching a position or features of an antenna of the mobile terminal can be recognized.

Abstract: A system and method are disclosed to track aircraft or other vehicles using techniques including multilateration and elliptical surveillance. Unlike conventional approaches that use time difference of arrival for multilateration at a fixed set of reception points, this technique allows targets to be tracked from a number of dynamic or moving reception points. This allows for triangulation/multilateration and elliptical surveillance of targets from combinations of fixed, fixed and moving or only moving ground-based receivers, sea-based receivers, airborne receivers and space-based receivers. Additionally this technique allows for ADS-B validation through data derived from only two receivers to assess the validity and integrity of the aircraft self-reported position by comparing the time of arrival of the emitted message at the second receiver to the predicted time of message arrival at the second receiver based on the self-reported position of the aircraft and the time of arrival at the first receiver.

Abstract: The present invention addresses the resolving of the problems associated with the passive location of targets in TOA (Time of Arrival) or TDOA (Time Difference of Arrivals) mode. The method of passively locating a target in TOA or TDOA mode implements a meshing (subdivision) into blocks of the space in which the location area is situated. The set of the blocks that form this mesh is analyzed iteratively. On each iteration, each block of interest is subdivided into smaller identical subblocks. A block of interest is, according to the invention, a block including at least one point belonging to the location area being sought for which the shape is to be determined. The iterative process is stopped when the size of the subblocks obtained on the current iteration corresponds to the desired resolution. The invention applies in particular to the 2D or 3D location systems that include TOA and TDOA modes or mixed modes.

Abstract: The invention relates to a method for increasing the accuracy of a measurement of a radio-based locating system comprising a mobile station and at least one fixed station, wherein the movement of a mobile station from an initial position is detected by way of measuring data of an absolute sensor system and a relative sensor system, a virtual antenna is embodied in the form of synthetic aperture by way of measuring data and the mobile station is focused on the fixed station and/or vice versa by using the synthetic aperture.

Abstract: A method and an apparatus to improve sensitivity of decoding time of a global positioning system (GPS) receiver at low signal to noise ratio is disclosed. In one embodiment, a method includes detecting a signal comprised of a data bits, arranging the data bits according to a specified property of an incremental mathematical table (e.g., may be an incremental bit-counter table), storing the data bits when arranging the data bits according to the specified property of the incremental mathematical table as a time counter table, algorithmically determining a value of an unknown data bit of the time counter table according to the specified property of the incremental mathematical table observed in the time counter table to generate a time counter value, and applying the time counter value to decode the signal.

Abstract: An apparatus for providing and detecting information regarding a person, location, or object includes a power supply, a helicoil dipole antenna, a transmitter, a receiver configured to receive signals from remote transmitters at a designated frequency, a computer processor, and a memory device configured to store an identifier associated with the apparatus. Logic instructions embedded on the memory device are configured to compare an identifier decoded from received signals to the identifier associated with the apparatus. When the identifier decoded matches the identifier associated with the apparatus, the instructions decode a return frequency from the signal, and generate return signals. The return signals include the identifier associated with the apparatus, the transmitter is activated only when the transmitter transmits the return signals at the return frequency.

Abstract: A method for producing a first time base for a first ultra wideband radio obtains a time reference signal and phase locks a clock signal to the time reference signal The clock signal is counted down using a counter to produce the first time base. The counter is a binary counter that has a modulo count equal to a modulo repeat length of a code corresponding to a ultra wideband signal.

Abstract: By using the delay profile created by delay profile creating section 102 and the first threshold value 330 received from the first threshold value calculation 105, the first threshold value timing detection section 103 selects only the earliest receive timing exceeding the first threshold value, from all the timing that the correlation value in the delay profile becomes a maximum. By using the receive timing and the second threshold value 331 received from the second threshold value calculation section 107, reference timing calculation section 106 selects the reference timing required for calculating the receive timing for the incoming wave of the minimum propagation delay time. The timing delayed by previously set timing behind said reference timing is sent from receive timing calculation section 108 as the receive timing 113 of the incoming wave of the minimum propagation delay time.

Abstract: Embodiments provide systems and methods for determining the geolocation of an emitter on earth. A solution is obtained from two TDOA measurements that need not be acquired at the same time. A solution is obtained from a TDOA measurement and an FDOA measurement that need not be acquired at the same time and need not be coming from the same satellite pair. A location of an emitter can be determined from minimizing a cost function of the weighted combination of the six solutions derived from the two TDOA measurements and the two FDOA measurements, where the weight of each solution in the combination is determined based on the intersection angle of the two curves that define the possible locations of the emitter based on the TDOA and/or FDOA measurements.

Abstract: The present invention provides a method and system for positioning an object with adaptive resolution. The method comprises: dividing a space to be detected into Hot Area and General Area; arranging, according to the positions of Hot Area and General Area, high-resolution positioning signal (US) transceivers and low-resolution positioning signal (RF) transceivers, wherein the detection scope of the low-resolution positioning signal transceivers covers the space and the detection scope of the high-resolution positioning signal transceivers covers the Hot Area; and when the object moving in the space, fusing the detection results from the high-resolution positioning signal transceivers and the low-resolution positioning signal transceivers to determine the position of the object with adaptive resolution. With the system of the present invention, for different areas, the object can be positioned with different positioning resolutions (precisions or granularities).

Abstract: A method and system for enhancing the performance of augmented services associated with a wireless communications system through the dynamic exploitation of current measurements and operational configuration parameters to accurately and effectively control the signal power and duration transmitted by the mobile unit of interest.