Abstract: Location of mobile units in a wireless local area network is based on use of signal strength ratios and other criteria. In one embodiment absolute value of signal strength is used to derive a second value of location. The second value may be used as the location if the system is not calibrated and may also be used to calibrate the system. Alternatively time difference of arrival may be used in combination with signal strength ratio.

Abstract: Methods, radios, components thereof, and other devices for localizing a geographic position of a radio receiver are provided. A current radio signature is obtained. The current radio signature comprises a plurality of measured signal qualities that collectively represent a frequency spectrum. Each measured signal quality in the plurality of measured signal qualities corresponds to a portion of the frequency spectrum. The current radio signature is compared with a plurality of reference radio signatures. Each reference radio signature in the plurality of reference radio signatures is associated with a global position. When the comparing identifies a unique match between the current radio signature and a reference radio signature in the plurality of reference radio signatures, the radio receiver is deemed to be localized to the global position associated with the reference radio signature.

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: The present invention reduces the number of base stations required to carry out terminal position detection. A base station which serves for terminal position detection using radio signals comprises an antenna to transmit and receive a radio signal; a radio signal receiver which generates a received signal from the radio signal received; a signal processing unit which processes the received signal and generates a transmit signal; a radio signal transmitter which generates a radio signal from the transmit signal; a control unit which exerts control of the base station operation; and a signal processing unit for position detection which performs signal processing for terminal position detection. A signal receivable range with which a signal can be received by the radio signal receiver is made longer than a signal transmission range with which a signal is transmitted by the radio signal transmitter.

Abstract: A Moving Transmitter Correlation Interferometer Geo-Location (MT-CIGL) system is disclosed that permits locating both moving and stationary transmitters from moving DF equipment. A conjugate gradient based search routine is utilized which solves for the location of moving and stationary transmitters at the start of each measurement sequence and then solves for the velocity and direction of motion of the moving transmitter. This information is used to track the moving transmitter. Received signals are sampled, digitized and stored in covariance matrices. They are then summed and normalized using an equation that has velocity terms that are set to zero to minimize extraneous correlation peaks, and a maximum correlation peak is developed. A conjugate gradient search routine is used to find the correlation peak of the summed data. The value of the peak is then analyzed to see if it is above or below a predetermined value.

Abstract: A location system for locating and determining the motion and velocity of a wireless device. The methods include direct inferences about whether a device is in motion versus static based on a statistical analysis of the variation of radio signal strengths over time. The system is trained according to a sparse set of identified locations from which signal strengths are measured. The system uses the signal properties of the identified locations to interpolate for a new location of the wireless device. The system uses a probabilistic graph where the identified locations of the floor plan, expected walking speeds of pedestrians, and independent inference of whether or not the device is in motion are used to determine the new location of the device.

Abstract: In order to improve the reliability and the accuracy of a position-finding method such as the GPS method, the quality of a radio link which is used for the position-finding method is determined by estimating a parameter, in particular the Rice factor of the amplitude distribution density, which is characteristic of the ratio of the strength of a signal transmitted via a line-of-sight path, with respect to the strength of the signals transmitted via non-line-of-sight paths.

Abstract: Unknown alignment biases of sensors of a tracking system are estimated by an iterative Kalman filter method. Current measurements are corrected for known alignment errors and previously estimated alignment biases. The filter time reference is updated to produce estimated target state derivative vectors. A Jacobian of the state dynamics equation is determined, which provides for observability into the sensor alignment bias through gravitational and coriolis forces. The target state transition matrix and the target error covariance matrix are propagated. When a new measurement becomes available, the Kalman gain matrix is determined, the state vector and covariance measurements are updated, and sensor alignment biases are estimated. The state vector, covariance measurements, and estimated sensor alignment biases are transformed to an estimated stable space frame for use in tracking the target and updating the next iteration.

Abstract: Methods and systems for electronically tracking the progress of teams as they cover an assigned geographic area are described herein. A server computer establishes a coverage area, divides the coverage area into a plurality of regions, and assigns each region to a team. Each team carries a tracking device capable of autonomously determining its present location without user assistance, thus allowing the team to focus on the assigned task, such as searching for a missing person, plowing a field, paving a road, etc. The server monitors the location of each tracking device as each team covers its assigned region, and updates on a visually displayed geographic map a historical path associated with each tracking device based on the monitored location of each tracking device. In this manner, users can quickly view the visual depiction of the historical to determine as yet uncovered areas.

Abstract: Apparatus, systems, and methods may provide operating system-independent geolocation information. A compact software and/or firmwave environment may be established prior to loading and/or initializing the main operating system. This environment, sometimes known as a pre-boot environment, may determine geolocation information and/or may provide user access to configuration information and methods, even when the operating system is absent or unavailable.

Abstract: A Real-time Emitter Locating (EL) System and Method is disclosed. The system provides a technique for taking in data sets (lines of bearing) from DF receivers and characterizing those signals with their respective probabilities of error. Then using a unique method, the preferred system applies a recursive processing technique to this continuous stream of data, displaying transmitter positions with significantly less uncertainty. Furthermore, the preferred system is able to perform these functions in real-time. The system is further capable of being fully automated to reduce the processing time and reduce the necessity of human intervention. Still further, in an alternative embodiment of the present invention the system can be remotely controlled over a communications network whereby collected locating data from a single DF set, or alternatively from more than one DF sets can be combined to arrive at estimated positions for a transmitter.

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: An architecture for minimizing calibration effort in an IEEE 802.11 device location measurement system. The calibration technique is based upon a regression function that produces adequately accurate location information as a function of signal strength regardless of gaps in the calibration data or minimally available data. The algorithm takes a set of signal strengths from known room locations in a building and generates a function giving (x,y) as a function of signal strength, which function may then be used for the estimation of new locations. Radial basis functions, which are simple to express and compute, are used for regression. The fact that the algorithm maps signal strength to continuous location makes it possible to skip rooms during calibration, yet still evaluate the location in those rooms.

Abstract: Correlation Interferometer Geo Location (CIGL) uses DF antenna array movement on an aircraft while taking a Plurality of sets of transmitted signal Measurements. Each measurement set is stored as data in a covariance matrix, and the matrices are each decomposed to yield measured array vectors. Using an array manifold table developed during calibration of the CIGI. system, and containing testing array vectors, the measured array vectors are each correlated to testing array vectors to develop a correlation Surface that includes compensation for perturbations Such as aircraft induced electromagnetic scattering, All the correlation surfaces are summed and normalized, with the resultant summation undergoing conjugate gradient processing to more accurately geo-locate the transmitter. Improved accuracy with fewer antennas and polarization independence are also achieved.

Abstract: Systems and Methods are described for determining proximity motion of a mobile wireless device around a fixed target node. The present invention provides a method of regressively analyzing the signal strength on a receiver node, which may be either the mobile wireless device or the fixed target node, as a function of time to determine the proximity of the sending node, which may be either the mobile wireless device or the fixed target node, to the receiving node. The method includes detecting motion of mobile wireless device with a fixed wireless device within a proximity range of less than about 15 cm, and more preferably within around 5 cm. The system provides accurate proximity motion sensing that is not susceptible to multipath effects, and which can be implemented in a wide variety of wireless applications.

Abstract: A wireless node location mechanism that dynamically adapts to changes to a surrounding physical environment that affect the propagation of radio signals. The wireless node location mechanism assesses radio signals from transmitters associated with a wireless node location infrastructure to adjust one or more parameters used to estimate location of a wireless node. In one implementation, path loss exponents are re-computed based on the signals transmitted between infrastructure radio transceivers. These path loss exponents are used, in one implementation, to compute the distance between a wireless node and a given infrastructure radio transceiver and, ultimately, to determine the location of the wireless node based on triangulation. In one implementation, path loss exponents are computed on demand based on the signals observed between infrastructure radios that detect the wireless node whose location is to be estimated.

Abstract: A multistatic radar has a radar transmitter for illuminating a target with a radar signal. The target reflects the radar signal to three separate radar receivers, each performing a bistatic range measurement to the target. The three bistatic range measurements are combined in a quadratic equation having two solutions (roots). One solution (root) corresponds to a correct three dimensional target position with respect to the radar transmitter while the other is an incorrect three dimensional target position with respect to the radar transmitter. The incorrect three dimensional target position is identified and eliminated by comparing the three dimensional target position to the transmitter location, and the receiver locations. The incorrect three dimensional target position is also identified by the target altitude exceeding a threshold, typically set above 80,000 feet AGL.

Abstract: The present invention employs approximate device locations determined from changes in the sensed strength of radio signals at different locations. In one instance of the invention, the approximate device locations are based on inference procedures that are used to process ambient commercial radio signals, to estimate a location or a probability distribution over the locations of a device. In another instance of the invention, approximate device locations derived from learning and inference methods that are applied to rank vector of signal strength vectors are utilized. Moving to such rank orderings leads to methods that bypass consideration of absolute signal strengths in location calculations. The invention utilizes approximations for a device location that is based on a method that does not require a substantial number of available ambient signal strengths while still providing useful location inferences in determining locations.

Abstract: A location system for locating and determining the motion and velocity of a wireless device. The methods include direct inferences about whether a device is in motion versus static based on a statistical analysis of the variation of radio signal strengths over time. The system is trained according to a sparse set of identified locations from which signal strengths are measured. The system uses the signal properties of the identified locations to interpolate for a new location of the wireless device. The system uses a probabilistic graph where the identified locations of the floor plan, expected walking speeds of pedestrians, and independent inference of whether or not the device is in motion are used to determine the new location of the device.

Abstract: A model construction module (MCM) for constructing a probabilistic model (PM) of a wireless environment (RN) in which a target device (T) communicates using signals that have a measurable signal value (x), such as signal strength. The model construction module forms several submodels (611–631) of the wireless environment (RN). Each submodel indicates a probability distribution (F1–F3) for signal values at one or more locations (Q1–QY) in the wireless environment. The module combines the submodels to a probabilistic model (PM) of the wireless environment (RN), such that the probabilistic model indicates a probability distribution for signal values at several locations in the wireless environment. Alternatively, the model may insert new locations to a single model based on a combination of existing locations. The combination of submodels or existing locations includes combining the inverse cumulative distribution functions of the submodels or existing locations.

Abstract: A transmitted signal's higher order statistics of temporally dependent waveforms are exploited to geolocate low power signals. The geolocation is independent of the characteristics or encoded data of the transmitted waveform. The method uses spatial fourth order cumulants or spatial second order moments in a Blind Source Separation and generalized eigenvalue decomposition to determine unique matrix pencil eigenvalues and eigenvectors. The eigenvectors provide are orthogonal to the steering vector of the transmitted signal save one, which represents the steering vector. This property is used to determine Steering vectors, AoA or geolocation. The receiver includes a multi-element array and does not need a priori knowledge of the transmitted signal source to geolocate the target transmitter. The methods and apparatus for geolocation does not require typical demodulation.

Abstract: Described herein is a system and method for detecting the position of a remote emitter (1) where the emitter (1) is emitting a radio frequency signal (2) in a radio field (3). The system and method uses at least one receiver (4) which is moveable within the environment of the radio field (3), each receiver (4) measuring and recording the amplitude of the radio frequency signal (2) and recording its precise location using a GNSS or GPS receiver. The data recorded is processed and compared to data predicted by the receiver(s) (4) to estimate a location of remote emitter (1).

Abstract: Methods and apparatuses for the processing of false alarms in position determination. At least one embodiment of the present invention estimates and uses measurement false alarm probabilities in the position determination process. In one embodiment, the estimated measurement false alarm probabilities are combined to determine the reliability of the determined position solution or the reliability of the set of measurements as a collection. In one embodiment, the estimated measurement false alarm probabilities are used in the isolation and elimination of faulty measurements. For example, the traditional geometry based metric for identifying a faulty measurement is further weighted according to the measurement false alarm probabilities in order to determine the faulty measurement.

Abstract: Techniques for determining the angles of arrival of multiple simultaneous cochannel sources using only a single RF receiver sampling and downconversion channel is disclosed. This is accomplished by sequentially forming several known mixtures of multiple antenna signals in the RF domain prior to downconversion and digitization. Angle of arrival information is then recovered through the application of higher order statistics and subspace fitting techniques. The same principles can be applied to other P-element receiver arrays (e.g., acoustical receiver array).

Abstract: Systems and methods for determining location by implication are described. A responsive environment includes a location determination method that operates in an area that is only partially instrumented with location-sensing devices. Some of the with location-sensing devices sense location ambiguously. For example, a location-sensing device may be deployed at a boundary between two target objects or areas of interest. The location of the target object, as reported by such devices, is considered ambiguous. While the object or person is known to be in a space, it is not clear which specific space. The location of ambiguously located objects can be disambiguated based on changes in the location of other objects. For example, if a document is placed on a shelf in an office, such action strongly implies that someone is in the office. Therefore, if a person is known to potentially be in the office or the outside hallway, the person's location is changed to be in the office.

Abstract: A method and system is provided for determining a location for each of a plurality of units, which is selected from one of multiple sets of locations, which are each estimated based upon different initial location estimates. The selected set of locations includes the set which has the minimum error value, where the error value is based on the aggregate of the differences between the range determined from the estimated locations and the measured range. By using different sets of initial location estimates, there is a greater chance that at least one of the sets of initial location estimates will avoid any local minimums and produce a more accurate estimate of unit locations.

Abstract: The time difference of arrival for a signal received at two or more receiving sites as transmitted from a wireless communications device, is determined by a frequency domain technique. The constituent frequencies of the signals received at the two or more receiving sites are determined, including the phase, or a value representative of the phase, of each frequency component. The phase values for the same frequency are subtracted to yield a phase difference values as a function of frequency. The slope of the function represents the time difference of arrival for the wireless communications device signal as received at the two receiving sites. To determine the mobile location based on the determined time difference of arrival values, a seed or initial location is first assumed for the wireless communications device and the distance difference of arrival (the time difference of arrival multiplied by the speed of light) is calculated.

Abstract: A location system for locating and determining the motion and velocity of a wireless device. The methods include direct inferences about whether a device is in motion versus static based on a statistical analysis of the variation of radio signal strengths over time. The system is trained according to a sparse set of identified locations from which signal strengths are measured. The system uses the signal properties of the identified locations to interpolate for a new location of the wireless device. The system uses a probabilistic graph where the identified locations of the floor plan, expected walking speeds of pedestrians, and independent inference of whether or not the device is in motion are used to determine the new location of the device.

Abstract: System and method to determine the location of a receiver in a multipath environment are provided. The received signal is correlated with the reference signals associated with the transmitting sources. Each correlation function is processed to derive various types of signal constraints, such as probability densities and uncertainty regions or intervals. In some embodiments, these constraints are for the code-phases and the Doppler frequencies. These signal constraints are transformed into constraints on the receiver variables and then fused together into a unified receiver constraint. A-priori constraints, such as constraints on the location of the receiver or the timestamp, may be incorporated into the unified receiver constraint. Some embodiments estimate a location based also on the estimated Doppler frequency. The constraints used by the invention are based on models of multipath effects and are geared towards mitigating these effects.

Abstract: Cell coordinates available in the radio network is used to determine an area where the mobile radio is located and does not rely upon mobile radio measurements. Such cell coordinates for cells currently associated with the mobile radio are used by the radio network to determine a location of the mobile radio. Those current cells may include cells that are candidates for supporting a communication with the mobile radio, an active set of cells, cells that are currently supporting communication with the mobile radio, or some other set of cells geographically associated with the mobile radio.

Abstract: A system and method for narrowband pre-detection signal processing in passive coherent location applications is disclosed. A receiving subsystem receives a reference signal and a target signal from an uncontrolled transmitter. The target signal is reflected from a target. The passive coherent location system includes subprocessors that perform pre-detection operations on the reference and target signals. The functions include zero-doppler cancellation, quadrature demodulation, reference beam regeneration, coherent processing interval selection, power spectral density estimation, cross ambiguity function formation, and the like. Within these operations, the reference signal is filtered with respect to the target signal to form a first output reference signal. The first output reference signal is combined with the first target signal to form a first output target signal. The output target signal then is used for subsequent passive coherent location processing operations.

Abstract: The present invention is directed to a system and method for Doppler track correlation for debris tracking in PCL radar applications. The disclosed embodiments describe the systems and methods used in the detection of debris pieces and the association of the Doppler signals from the debris pieces across multiple illumination channels. The present invention also provides computation of debris state vectors and the projection of trajectories to determine debris impact points.

Abstract: An architecture for minimizing calibration effort in an IEEE 802.11 device location measurement system. The calibration technique is based upon a regression function that produces adequately accurate location information as a function of signal strength regardless of gaps in the calibration data or minimally available data. The algorithm takes a set of signal strengths from known room locations in a building and generates a function giving (x,y) as a function of signal strength, which function may then be used for the estimation of new locations. Radial basis functions, which are simple to express and compute, are used for regression. The fact that the algorithm maps signal strength to continuous location makes it possible to skip rooms during calibration, yet still evaluate the location in those rooms.

Abstract: A process for determining the location of entities carrying transmitters (TXs) that transmit TX ID messages to at least one receiver (RX) connected to a computer, in a network of computers. Each RX sends data messages to its associated computer which includes an identifier identifying the TX transmitting the TX ID message, the signal strength of the received TX ID message, and a RX identifier. Each RX computer generates badge hit messages from each data message, and provides them to a centralized computer of the network. The centralized computer generates a badge hit table having a separate entry for each badge hit message, which has fields including the information received in the badge hit message and a hit time indicating the time the entry was added to the table. The badge hit table data is used to determining the location of the TXs, and so the entities.

Abstract: This invention relates to a method and system for the radio location of CDMA and non-CDMA enabled transmitters within a reception zone. The invention exploits the superposition of antenna patterns that create complex and asymmetrical interference structures at very small scales. By randomly distributing a random antenna array of M elements across a two or three-dimensional surface, fine scale interference structures on the scale of ¼ the carrier wavelength are generated. Once the minimum number of antennas are placed, additional antennas will not improve the resolution. Such interference structures when sampled at ? the carrier wavelength or greater yields unique spatial patterns with respect to a given antenna array geometry and transmitter location. The invention incorporates signature recognition (matching) and orthogonal sub-space projection estimators to derive location estimates of a radio transmitter.

Abstract: A system and method for rapidly determining the source of an incoming projectile applies controlled, active RF energy source(s) to illuminate a target area/projectile, and exploits Doppler induced frequency shifts from multiple receivers to develop a vector solution. The preferred solution applies continuous wave (CW) RF illuminators to flood a local region with a controlled source of radio frequency energy and one or more displaced receiver elements. The system operates multi-statically and as an incoming projectile enters the illuminated region, reflected energy from one or more illuminators is detected by one or more displaced RF receivers. Doppler shifts imparted on the reflected signals are detected by the receivers as the projectile moves through the region. Appropriate processing of the receiver outputs generates Doppler time-frequency profiles that are used to derive an estimate of the projectile flight vector in 3-space (x,y,z).

Abstract: In a method and system to determine the position of a target by means of an IFF type antenna, the antenna having a given direction of aim, the method comprises a step for combining the distance D from the target to the carrier, the altitude A of the target, the altitude Apf of the carrier equipped with the IFF antenna and the angular error value of the target and the direction of aim of the antenna beam to localize the target with precision. Application to IFF interrogations in mode C.

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 section 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: A certain amount of basic map data is installed into the map data storage medium in the navigation apparatus at the time of initial setting or the like (this process will be hereinafter referred to as “pre-install”), and thereafter the user connect to the map data providing center to download necessary data according to need. Thus, the present invention offers efficient method of obtaining map data in the communication-type navigation system.

Abstract: A system and method for narrowband pre-detection signal processing in passive coherent location applications is disclosed. A receiving subsystem receives a reference signal and a target signal from an uncontrolled transmitter. The target signal is reflected from a target. The passive coherent location system includes sub-processors that perform pre-detection operations on the reference and target signals. The functions include zero-doppler cancellation, quadrature demodulation, reference beam regeneration, coherent processing interval selection, power spectral density estimation, cross ambiguity function formation, and the like. Within these operations, the reference signal is filtered with respect to the target signal to form a first output reference signal. The first output reference signal is combined with the first target signal to form a first output target signal. The output target signal then is used for subsequent passive coherent location processing operations.

Abstract: A location system for locating and determining the motion and velocity of a wireless device. The methods include direct inferences about whether a device is in motion versus static based on a statistical analysis of the variation of radio signal strengths over time. The system is trained according to a sparse set of identified locations from which signal strengths are measured. The system uses the signal properties of the identified locations to interpolate for a new location of the wireless device. The system uses a probabilistic graph where the identified locations of the floor plan, expected walking speeds of pedestrians, and independent inference of whether or not the device is in motion are used to determine the new location of the device.

Abstract: A wireless means of guidance for a device in accordance with the present invention includes receiving signals from at least one wireless base station indicating at least a respective position thereof, determining the current position of the device using at least the information contained in the received signals, calculating a vector between the determined current position and a predetermined desired destination for the device, and making trajectory corrections to the device's current trajectory so as to guide the device to the desired destination. In addition to the information contained in the received signals, the guidance system may also use stored information regarding parameters, such as the location, communication protocols and operating frequencies of the wireless base stations, as well as previous position information, for determining a current position for the device.

Abstract: The present invention is intended to provide a system for determining the precise launch point of ballistic missiles, and may additionally provide the capability of neutralizing said threats. The invention provides a mobile object information means configured to classify electromagnetic frequency activity within satellite and land based commercial and private broadcast and telecommunications spectra in a given geographical area, said means also configured to classify associated area weather normality and anomalies. The system includes a software algorithm configured to extract from said database, a missile launch in a given geographical zone by “tagging” an electromagnetic wave disturbance caused by the high intensity initial fuel burn of said missile launch.

Abstract: A system and method for central association and tracking for PCL applications is disclosed. Detection reports are received at a target tracking processing system. The detection reports include measurements correlating to line tracks associated with target echoes in earlier processing operations. In addition, other information, such as parameters and observables, are received by the target track processing system. The target track processing system performs a line track association function and a track filtering function on the line tracks according to the measurements within the detection reports. These operations also predict and estimate target parameters for tracking. Target parameters are extrapolated from the propagated and updated target tracks, and fed to a display for a user, or back into the PCL system for further processing.

Abstract: Emitter target range and heading are estimated from bearing measurements enhancing bearings-only estimator convergence to a target track, and permitting optimization of an observer position relative to the target at the end of the total bearing measurement period. One or more estimates of the target range, speed and heading made from bearing measurements before an observer maneuver are used to determine the most appropriate observer maneuver giving complete bearings-only target-motion-analysis observability. A set of parameters characterizing a set of potential emitter signal sources is generated based on measured emitter characteristics. A most probable set of emitter platforms is identified and the emitter operating mode and corresponding platform set are associated with a kinematic regime set. A specific speed or discrete set of speeds best adapted to a set of all possible platform missions, emitter speed as a continuous function of emitter range, and emitter range are all determined.

Abstract: A system and method for wideband pre-detection signal processing for PCL applications is disclosed.

Abstract: A transmitted signal's higher order statistics of temporally dependent waveforms are exploited to geolocate low power signals. The geolocation is independent of the characteristics or encoded data of the transmitted waveform. The method uses spatial fourth order cumulants or spatial second order moments in a Blind Source Separation and generalized eigenvalue decomposition to determine unique matrix pencil eigenvalues and eigenvectors. The eigenvectors provide are orthogonal to the steering vector of the transmitted signal save one, which represents the steering vector. This property is used to determine Steering vectors, AoA or geolocation. The receiver includes a multi-element array and does not need a priori knowledge of the transmitted signal source to geolocate the target transmitter. The methods and apparatus for geolocation does not require typical demodulation.

Abstract: A system and method for measurement domain data association in a passive coherent location system is disclosed. According to the system and method, detection reports are received and associated with line tracks. The detection reports correlate to target signals received at the passive coherent location system. Measurements of the detection report correlate to the data of the target signals. A line track state estimation function associates new detection reports with the line tracks and estimates update states for the line tracks. A signal type is determined. Kalman filters are selected for the measurements according to the signal type. Measurement residuals are computed for the detection reports according to the Kalman filters. The detection reports are selected for association with the line tracks according to the residuals. The line tracks can be merged or terminated during updates according to specific criteria. Further, new line tracks are initialized as new targets are detected.

Abstract: Methods and apparatuses for the processing of false alarms in position determination. At least one embodiment of the present invention estimates and uses measurement false alarm probabilities in the position determination process. In one embodiment, the estimated measurement false alarm probabilities are combined to determine the reliability of the determined position solution or the reliability of the set of measurements as a collection. In one embodiment, the estimated measurement false alarm probabilities are used in the isolation and elimination of faulty measurements. For example, the traditional geometry based metric for identifying a faulty measurement is further weighted according to the measurement false alarm probabilities in order to determine the faulty measurement.

Abstract: The present invention is useful in connection with calibration of a wireless location system based on RF signals within a facility. Identification devices are provided at fixed locations which are selected within the facility. The RF environment is sampled at selected locations and data representing the sampled RF environment and the corresponding selected location is provided to a computer which maintains a database corrolating the RF environment data and the selected locations to be used with calibrating a location system.