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.

Abstract: The invention relates to methods and devices for precise geolocation of low-power, broadband, amplitude-modulated rf and microwave signals having poor coherency. The invention provides a basis for dramatic improvements in RF receiver technology, offering much higher sensitivity, very strong rejection of unintended signals, and novel direction finding techniques. When mounted on an airborne surveillance platform, the invention can detect and geolocate weak, broadband, incoherent RF and/or microwave signals. Embodiments of the invention are implemented by dual channel receivers (heterodyne or tuned-RF) that use crystal detection and Fast Fourier Transform (FFT) analysis for geolocation. Geolocation is accomplished using a subsystem of phased arrays and an angle of arrival technique.

Abstract: A novel method and apparatus for determining geolocation of a mobile transmitter is provided. The apparatus and the method utilize an orthogonal projection of a source signal to canceling interference from the source signal in the geolocation process.

Abstract: A local positioning system (LPS) uses the radio propagation parameters in a CDMA forward link or TDMA reverse link to establish a mobile station's position. The mobile station receives pilot channel signals from at least three distinct base stations and records the PN chip offset of the pilot channel signals. The LPS time difference of arrival triangulation approach requires no additional signal detection capabilities. Base stations send out pilot channel signals that arrive at a mobile station with a particular phase and at least a predetermined minimum strength. The mobile station reports back the “visible” pilot channel signals, their phases and signal strength to the LPS which uses a location non-linear system, expressed as a set of cost functions, to estimate the mobile location. The LPS can also solve the 9-1-1 mobile location problem for wireless CDMA systems by determining the position of a person in distress that has a digital cellular phone.

Abstract: A system and method for detection and feature extraction in a passive coherent location system is disclosed. During a coherent processing interval, detection and feature extraction operations are performed to determine peak detections and target parameters for targets. The system forms an ambiguity surface that has ambiguity surface data or the coherent processing interval. Bins from a previous ambiguity surface are associated with the ambiguity surface data. New bins are identified for new target echoes within the ambiguity surface. Peak detections are formed from the bins. The peak detections correlate to the target echoes of the coherent processing interval. Target parameters for the targets are estimated from the peak detections.

Abstract: A system for locating electromagnetic signal sources via the rotational Doppler effect whereby a radar station generating electromagnetic signals, such as radar frequency signals, initially scans the sky for aircraft. An aircraft having the system operationally installed thereon and utilizing apparatus or navigational systems already present on the aircraft receives radar signals. The system is programmed to capture radar signal parameters and extract the rotational Doppler frequencies induced by the motion of the aircraft. The angular velocity of the host platform is often the dominant source of this frequency; however, lateral velocity is not detrimental to the process. The measurement of the rotational Doppler frequency is accomplished through antennas presently installed on large numbers of military aircraft with no requirement for phase calibration of the electrical paths between antennas and receiver.

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

Abstract: A method and apparatus for providing for real time automated control of the position of a blade on a earth-moving machine. The method includes providing a geography altering machine, including a blade and a computer, the computer having stored therein a reference line and a three dimensional computer model of a desired topography, providing a user defined offset relative to the reference line, determining a blade position in local coordinates, converting the local coordinates to reference line coordinates, utilizing the reference line coordinates and the user defined offset to calculate blade movement commands, and moving the blade in a direction required by the blade movement commands.

Abstract: Under a multi-path environment, receive timing for the incoming wave of the minimum propagation delay time cannot be accurately measured using the prior art. 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.

Abstract: A camera guidance system uses global navigation satellite systems (GNSS) and Inertial Measurement Units (IMU) to point a camera on a target.

Abstract: This invention concerns a method for passive localization of a target (12) and air-air localization in particular.

Abstract: A method and system for pacing a vehicle along a path of travel is described. The method includes determining a geographical location of the vehicle, displaying a vehicle position icon representative of the geographical location, determining an optimal position for the vehicle, displaying a pace icon representative of the optimal position for the vehicle, and operating the vehicle to maintain a vehicle position icon displayed on the operator pace display substantially coincident with the pace icon displayed on the operator pace display.

Abstract: Surveillance platforms detect dangers and transmit information signals describing the dangers to a control center, which determines the degree of danger and its geographic extent. The center generates a message that identifies the degree of danger and GPS coordinates of the impacted geographic area for a region. A vulnerability index determined using neural networks and fuzzy logic enables a prioritized message. The center broadcasts the message to remotely located warning devices, which compare the received danger coordinates with their own GPS coordinates and determine the extent to which they are in danger. Warning signals can issue automatically, appropriate to the degree of danger. Emergency manned vehicles may also directly receive the broadcast message and act appropriately relative to the degree of danger.

Abstract: An apparatus and method for combining a survey measurement dataset and a position dataset into a single dataset containing both measurement and position data is disclosed. The survey measurement data may be obtained from a ground penetrating radar, an inductometer, a magnetometer, or an optical camera. Positioning information is collected and merged with the survey information so that the position of the survey tool is known at each data point. Also provided are channel-equalization filters, spiking deconvolution filters, and frame filters that can be used in conjunction with the positioning information to enhance the quality of the images obtained from the data collected by the survey tool.

Abstract: Weighted ridge regression (WRR) processing is applied to three or more distance measurements to determine the location of a terminal. For example, in an integrated satellite-based navigation system/wireless network, the location of a mobile unit can be determined by applying WRR processing to at least three distance measurements, where one or more of the distance measurements are satellite-based distance measurements (e.g., GPS pseudorange measurements) and one or more are wireless network-based distance measurements (e.g., round-trip delay or pilot phase offset measurements). WRR processing provides improved accuracy in the determination of mobile unit position over conventional least mean square techniques.

Abstract: A global positioning system for use with a plurality of transmitting satellites is disclosed wherein a full position solution is obtained from a number N of satellite transmissions and a plurality of sub-solutions each based on a different number (N−1) of satellite transmissions are obtained to determine if a satellite is faulty. A plurality of sub-sub-solutions is then obtained based on a different combination of N−2 satellites with each combination containing the satellites of different sub-solutions and excluding one other satellite in addition. An examination of the sub-sub-solutions provides an indication of which one of the satellites is the failed satellite.

Abstract: A method and system for testing network-based location determination technologies within a single test area in the field. Channel models are developed to simulate the propagation impairment conditions associated with identified test scenarios. The channel models for an identified test scenario can be developed by estimating the amount of multi-path, path loss, and Doppler frequency shift effects one would expect under the conditions and environment of the identified tests scenario. The path loss effects of an identified scenario may be estimated by combining the Okumura-Hata outdoor path loss models with available indoor path loss models. A single test area having receiving antennas and signal transmission of fixed and known geographic locations may be selected.

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

Abstract: Techniques for location tracking, location utilization, and dissemination and management of location information are disclosed. As a location monitoring system, one embodiment includes at least a plurality of mobile computing devices supported by a wireless network, and a web server coupled to a wired network (e.g., the Internet) that couples to the wireless network. Each of the mobile computing devices are associated with and proximate to an object whose location is being monitored. The web server stores the locations of each of the mobile computing devices or the objects proximate thereto, and enables only authorized users to obtain access the locations via the wired network.

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: Attitude of a spinning vehicle is determined by observing at least one of the apparent amplitude modulation and the apparent phase modulation of a navigation signal received from a navigation source. Vectors describing the direction from the vehicle to the navigation source are computed and used to determine attitude relative to the navigation source. Inertial sensors are demodulated to remove rotation artifacts and used to anticipate rapid maneuvers.

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 method, system, and computer program product for determining the location of a portable data processing system is provided. In one embodiment, the portable data processing system determines resources that are geographically proximate to the portable computer and generates a location syndrome. The location syndrome is then compared to a set of location profiles, wherein at least some of the location profiles correspond to different geographic locations. Responsive to sufficiently matching the location syndrome to one of the set of location profiles, a label corresponding to the matched one of the set of location profiles is returned as the current location of the portable data processing system.

Abstract: A system and method for detection and feature extraction in a passive coherent location system is disclosed. During a coherent processing interval, detection and feature extraction operations are performed to determine peak detections and target parameters for targets. The system forms an ambiguity surface that has ambiguity surface data or the coherent processing interval. Bins from a previous ambiguity surface are associated with the ambiguity surface data. New bins are identified for new target echoes within the ambiguity surface. Peak detections are formed from the bins. The peak detections correlate to the target echoes of the coherent processing interval. Target parameters for the targets are estimated from the peak detections.

Abstract: The invention relates to methods and devices for precise geolocation of low-power, broadband, amplitude-modulated rf and microwave signals having poor coherency. The invention provides a basis for dramatic improvements in RF receiver technology, offering much higher sensitivity, very strong rejection of unintended signals, and novel direction finding techniques. When mounted on an airborne surveillance platform, the invention can detect and geolocate weak, broadband, incoherent RF and/or microwave signals. Embodiments of the invention are implemented by dual channel receivers (heterodyne or tuned-RF) that use crystal detection and Fast Fourier Transform (FFT) analysis for geolocation. Geolocation is accomplished using a subsystem of phased arrays and an angle of arrival technique.

Abstract: Methods for comparing three-dimensional space curves are provided. Such methods are particularly useful for map matching in in-vehicle navigation systems as well as for other applications that require accurate positioning of the vehicle with respect to the underlying map data referenced by the system. Additionally, they are useful in measuring and/or evaluating the accuracy of a geographic database. Two angles that define the angular orientation of a three dimensional space curve are determined at corresponding locations for each of a first space curve and a second space curve. The variance of the relationship between the angle pairs at corresponding locations along the first and second space curves is utilized to determine the similarity between the first and second space curves despite any spatial translation and angular rotation between the first and second space curves.

Abstract: Methods, systems and data structure for storing and managing information in a wireless network are described wherein fixed resources in the system are stored in a database in a hierarchical directory structure according to the location of each fixed resource. Each level of the directory structure represents a geographical area in which a fixed resource is located. The lowest level of the directory structure represents the location of the smallest geographical area in which a fixed resource is located, and the highest level of the directory structure represents the location of the largest geographical region in which the fixed resource is located.

Abstract: Under a multi-path environment, the receive timing for an incoming wave of the minimum propagation delay time cannot be accurately measured in the prior art. 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 timings 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, the 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.

Abstract: A fully-coupled vehicle positioning method and system with differential GPS substantially solves problems encountered in either the global positioning system-only or the inertial novigation system-only, such as loss of global positioning satellite signal, sensitivity to jamming and spoofing, and an inertial solution's drift over time, in which the velocity and acceleration from an inertial navigation processor of the integrated GPS/INS system are used to aid the code and carrier phase tracking of the global positioning system satellite signals, so as to enhance the performance of the global positioning and inertial integration system, even in heavy jamming and high dynamic environments. To improve the accuracy of the integrated GPS/INS navigation system, phase measurements are used and the idea of the differential GPS is employed. A master-slave relative positioning scheme is invented and is effective for high accuracy formation driving and flight.

Abstract: Methods and apparatus for determining location information corresponding to a volume in space (VIS) that is occupied by a selected target from a remote observation platform through the process of collecting an identification signal from a source at or near the selected target and associating VIS location information data with that signal to identify location information corresponding to the VIS occupied by the target.

Abstract: An object device wirelessly communicating with at least one node is located. The nodes wirelessly communicating with the object device are discovered. The nodes are discovered either by querying nodes to discover whether the object device is wirelessly communicating with the nodes or querying nodes to discover devices wirelessly communicating with each node, generating an index of devices wirelessly communicating with each node and the nodes to which each device is wirelessly communicating, selecting the object device from the index, and reading the index to discover the nodes wirelessly communicating with the object device. For each node wirelessly communicating with the object device, a location of a coverage area for the node is discovered. The location of the coverage area for each node is discovered by either reading the location of the coverage area for each node or reading a node location and calculating the location of the coverage area from the node location.

Abstract: A cellular telecommunications system comprises a plurality of transceiver stations forming a network for transmission of signals between a mobile communications device and an internet based server hosting an application which is dependent on the position of the mobile device. The position of the mobile device is provided to the application as part of the initial request for the service from the device, thus avoiding the need for multiple flows of information. The position may be based simply on the known location of the transceiver station with which the device establishes wireless connection, with directional or signal strength range information added, if available. Alternatively, the position may be estimated more accurately from the signal received at multiple transceiver stations. In either case an accuracy estimate can be added to the determined position.

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

Abstract: A navigation system provides route guidance to a destination even when a facility in an unmapped area is input as the destination. When a facility in an unmapped area is input as a destination, the navigation system obtains a guidance route to an appropriate freeway exit near the facility, thus guiding a vehicle along the guidance route. Subsequently, the navigation system displays an arrow indicating the direction from a vehicle position to the facility and a linear distance from the vehicle position to the facility, thus guiding the vehicle to the destination. The guidance is provided until the vehicle arrives at the destination.

Abstract: A reader geometry visualization tool for a geo-location system technician's personal computer is operative to display a map of an asset management environment. The technician interactively places and manipulates a distribution of tag transmission readers and any potential impairments to RF transmissions on the map. The locations of the readers (and any impairments) are coupled as input parameters to a mathematical model of a tag-based geo-location system. The performance of the map-parameterized geo-location system model is then computed as a geometric dilution of precision (gdop) value for the intended object coverage area. The computed (gdop) performance is visually characterized on the displayed map, as by way of different colors to indicate how accurately the proposed reader geometry will enable the system to locate objects anywhere in the coverage area.

Abstract: A method of detecting a position of a radio mobile station in radiocommunications, which is capable of accurately and simply finding the position of the mobile station. At a measuring point the mobile station measures the reception radio strength levels from a plurality of base stations and conveys the measurement results through the base station to a control station. The control station learns, through a neural network, the correlation between the reception radio strength levels and the position of the mobile station on the basis of the measurement results at a plurality of measuring points and the positions of the measuring points. Subsequently, when the mobile station communicates to the control station the reception radio strength levels measured at an arbitrary point, the control station estimates the position of the mobile station, causing those measurement results, on the basis of the correlation obtained through the learning.

Abstract: A system and method for providing remote viewing of satellite transponder plots. The system and method piovides for remote viewing of transponder plots derived from transponders located on a satellite that communicate with ground terminals having an antenna. The system comprises an antenna switch for receiving transponder signals from the antenna. A spectrum analyzer is coupled to the antenna switch for generating transponder plots. An equipment control computer is coupled to the antenna switch and the spectrum analyzer that selectively routes signals from the antenna switch to the spectrum analyzer and routes transponder plots generated by the spectrum analyzer. A server computer is coupled to the equipment control computer that stores the transponder plots generated by the spectrum analyzer that are routed by the equipment control computer.

Abstract: The present invention is in general related to automatic alignment in multi-sensor target tracking. The process of the invention repeatedly generates estimates for sensor bias errors (b) by minimising a function, given on one hand by the magnitude of the discrepancy between measurements (M) and a measuring model, where the measuring model is a function of the unknown target location and unknown bias parameters, and on the other by the bias parameters and their predetermined statistical distributions (15). In a preferred embodiment of the present invention, the minimizing step is performed by linearising components of the function around an approximate target position (normally obtained from the tracker (10)) and around nominal (typically zero) bias errors, and the function is subsequently minimized with respect to target positions as well as to the bias parameters (b). In addition, possible time dependence of the bias parameters are modelled by the incorporation of process noise.

Abstract: A method of detecting a position of a radio mobile station in radiocommiunications, which is capable of accurately and simply finding the position of the mobile station. At a measuring point the mobile station measures the reception radio strength levels from a plurality of base stations and conveys the measurement results through the base station to a control station. The control station learns, through a neural network, the correlation between the reception radio strength levels and the position of the mobile station on the basis of the measurement results at a plurality of measuring points and the positions of the measuring points. Subsequently, when the mobile station communicates to the control station the reception radio strength levels measured at an arbitrary point, the control station estimates the position of the mobile station, causing those measurement results, on the basis of the correlation obtained through the learning.

Abstract: A navigation system that provides guidance information if more than three guide intersections are successively located adjacent each other. The vehicle navigation system's guidance information output is controlled on the basis of the successive relationships between respective intersections and is stored as programs in a memory medium.

Abstract: A route guidance system for a pedestrian. An input unit inputs a departure point and a destination point of the pedestrian. A route data memory stores route data representing position and connection of each route comprising a road network. A route calculation unit calculates a route from the departure point to the destination point by referring to the route data in said route data memory. A landmark memory stores landmark data for the pedestrian's confirmation; a landmark represents a signpost of the departure point, the destination point, and the route. A landmark selection unit selects the landmark data corresponding to the route calculated by said route calculation unit from said landmark memory. A presentation unit presents a route guidance to the pedestrian using the calculated route and the selected landmark data.

Abstract: A car navigation apparatus includes a route setting unit for setting a route; an own car position detection unit for measuring an own car position and detecting the own car position; and an advance direction detection unit for detecting an advance direction of the own car. The car navigation apparatus further includes a turning intersection detection unit for detecting an intersection where the own car should turn next time, on the route located within a predetermined distance in the advance direction from the own car position; and a turning intersection display unit responsive to detection of a turning intersection to display the shape of the turning intersection and a direction to which the own car should turn, acquired from map information stored in a map information storage unit, on the display screen using figures, and to display the distance to the turning intersection and the name of the turning intersection on the display screen using characters.

Abstract: A signal processing system is provided which describes a method and apparatus to determine the absolute time of arrival of a transmitted signal and to determine the location of a transmitting device by determining the relative difference in time that a transmitted signal is received at three or more receivers which are spaced apart with respect to each other. The method and apparatus is applicable to all systems which transmit discrete signals or signals which comprise composite components. The system comprises a ramp detection component to track the arrival of the signal and to determine, to a high time resolution, the arrival of a signal by identifying a particular feature of the transmitted signal. The time-of-arrival of the signal is determined with reference to a timing circuit.

Abstract: A method for visualizing radio waves which can only one sensor station to accurately specify the positions of a plurality of radio wave sources operating in the same frequency band and which can monitor a state of utilization of the radio waves. In a sensor station performing a radio wave hologram observation, one or more scanning antennas for scanning along a predetermined path and a plurality of fixed antennas having different directions and positions are provided. A signal received at the scanning antenna interferes with another signal received at the fixed antenna for each fixed antenna while the scanning antenna scans along the predetermined path, thereby obtaining a complex scanning data matrix for which complex weighting and addition processing is performed so that distribution of the radio wave sources is reconstructed.

Abstract: This invention provides a method and apparatus to provide coordinated evasive maneuver commands to aircraft to avoid collisions. More specifically, the invention comprises a GPS system to determined the location of aircraft, control logic to calculate evasive maneuvers, display aircraft tracking information, coordinate the evasive maneuver with the intruding aircraft, and give a synthetic voice warning and command to the pilots.

Abstract: A method of detecting a position of a radio mobile station in radiocommunications, which is capable of accurately and simply finding the position of the mobile station. At a measuring point the mobile station measures the reception radio strength levels from a plurality of base stations and conveys the measurement results through the base station to a control station. The control station learns, through a neural network, the correlation between the reception radio strength levels and the position of the mobile station on the basis of the measurement results at a plurality of measuring points and the positions of the measuring points. Subsequently, when the mobile station communicates to the control station the reception radio strength levels measured at an arbitrary point, the control station estimates the position of the mobile station, causing those measurement results, on the basis of the correlation obtained through the learning.

Abstract: A portable weather indicating device includes a housing with a display that can be carried by a user during hiking, biking, or other activities. A communication link and microprocessor are located in the housing for receiving and processing weather data. A global locating device, such as a global positioning system (GPS) receiver, inputs a user's location into the microprocessor. The display receives data from the microprocessor that is representative of at least one graphical weather image. The graphical weather image indicates the location input from the global locating device and the weather data. The graphical weather image includes an area encompassing the user's location and a location marker representative of the user's location within that area. A system for displaying weather data includes the portable weather indicating device and one or more base stations positioned at different locations.

Abstract: An improved fully-coupled vehicle positioning process and system thereof can substantially solve the problems encountered in global positioning system-only and inertial navigation system-only, such as loss of global positioning satellite signal, sensibility to jamming and spoofing, and inertial solution's drift over time, in which the velocity and acceleration from an inertial navigation processor are used to aid the code and carrier phase tracking of the global positioning system satellite signals, so as to enhance the performance of the global positioning and inertial integration system, even in heavy jamming and high dynamic environments. The improved fully-coupled GPS/IMU vehicle positioning system includes an IMU (inertial measurement unit) and a GPS processor which are connected to a central navigation processor to produce navigation solution that is output to an I/O (input/output) interface.

Abstract: The present invention determines the geolocation of an emitter, using at least one observer measuring signal change while moving on at least two observation tracks. The measurement of emitter signal change is begun between a first observer position and a second observer position. The second observer position is predicted at the time the last measurement from which signal change will be derived is made. The method utilizes knowledge of the measurement start and end points to determine a second pair of observer signal-change measurement start and end positions such that the emitter line-of-position (LOP) determined by the second signal change measurement will intersect the LOP associated with the first signal change measurement at possibly multiple points, but at each of these point intercept orthogonally to within the signal change measurement errors.