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

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

Abstract: A method and apparatus for determining the geographic location of a user incorporates the sensing of a plurality of physical environmental parameters at the user's location. The parameter values are compared to corresponding parameter values associated with known locations, and a best-fit correlation is established. The identity of the determined location may be displayed to the user, or may be used to control a location-based operation, such as the unlocking of a safe, the transmission of an entry password, or the disabling of a piece of equipment. Persistence weighting values for different environmental parameters may be applied to improve the reliability of the correlation.

Abstract: A Global Navigation Satellite System (GNSS) receiver and associated method for the reception and processing of GNSS signals. The GNSS receiver includes an antenna and an analog front-end to intercept the incoming radio-frequency signal and to convert it to an appropriate intermediate frequency for digital sampling. A baseband signal processor is organized into functionally identical channels, each dynamically assigned to a different satellite visible. The baseband signal processor processes the signal samples to generate the satellite signal channel impulse response for a number of Doppler frequency shifts. This results in a two-dimensional delay-Doppler map of satellite signal responses from which the baseband signal processor extracts the code time and carrier phase and frequency parameters as well as navigation data for timing, positioning, and environment mapping in the data processor.

Abstract: A positioning system is provided having a first signal source for originating synchronous signals, and a second signal source for originating a signal which is not synchronous with the signal from the first signal source. The system determines, based on a signal propagation time and signal propagation speed from the first or second signal source, the distance to this signal source so as to determine a position of a receiving point.

Abstract: A timepiece comprises a reception subunit, a timekeeping unit that holds internal time data indicative of the current time, storage, and a CPU. The CPU determines whether the internal time data acquired from the timekeeping unit matches correction time data stored in storage, selects a GPS satellite represented by satellite identification data stored in the storage when the determination is affirmative, acquires GPS time data included in navigation data which in turn is included in a GPS signal obtained from the selected GPS satellite, corrects the internal time data based on the GPS time data, and stores the correction time data in correspondence to the satellite identification data representing that GPS satellite.

Abstract: A position measurement system for measuring displacement of an observation station viewed from a reference station by receiving radio waves from satellites by these stations, and performing relative position measurement between the stations, having: a short period displacement measurement section for measuring a short period displacement component in each of the stations through independent position measurement; a relative position computing section for performing relative position measurement between said stations; a long period position computing section for inputting a short period displacement component measured by the short period displacement measurement section, a relative position determined by the relative position computing section and an absolute position from the reference station, and determining the absolute position including a long period displacement component by removing the short period displacement component measured by each of the stations; and a radio communication device installed on ea

Abstract: An incoming wave number estimation device for receiving incoming radio waves by an array antenna in which a plurality (=M) of antenna elements are linearly arrayed with a same element spacing, and estimating the number of the incoming radio waves, including: a correlation matrix creation section for removing a diagonal element from a predetermined row or column constituting an M×M array covariance matrix, and creating a correlation matrix by extracting a predetermined p number of correlations from (M?1) number of correlations after the diagonal element is removed while sequentially shifting one element at a time, and arraying the p number correlations in a matrix; an estimation matrix creation section for creating an estimation matrix for estimating the incoming wave number using the correlation matrix; a QR decomposition section for performing QR decomposition on the estimation matrix; and an incoming wave number determination section for determining the number of incoming radio waves based on each row eleme

Abstract: In a method and system for deriving a seed position of a subscriber station in a wireless communications system in supporting unassisted GPS-type position determination is provided, the subscriber station receives overhead messages from the wireless communications system, and derives the seed position from the parameter values. The subscriber station may use a data structure in its memory and map possible parameter values to corresponding positions that may serve as the seed positions.

Abstract: A positioning system includes a positioning device with a local antenna. One or more remote antennas are also connected to the device. The system selects one or more antennas to use in determining a position based at least in part on an orientation of the device. Other factors which may be used in selection include: a particular environment of the device, manual override, signal quality, and a stage in a workflow process.

Abstract: The present invention provides methods and systems that enable a mobile navigation receiver to accurately determine its trajectory with non-current ephemeris in stand-alone mode. In an embodiment, the receiver computes the position for the same location using non-current ephemeris and current ephemeris at different time instances. The receiver then determines a position correction by finding the difference between these two computed positions, and applies this correction to the trajectory generated with non-current ephemeris to obtain a more accurate trajectory. In another embodiment, the receiver computes an initial position of the receiver using non-current ephemeris and finds the difference between the computed initial position and an accurate approximation of the initial position. The receiver then shifts the subsequent receiver trajectory computed using non-current ephemeris by the difference to obtain a more accurate trajectory.

Abstract: When a user of a mobile communication terminal makes a request for a position-measuring of a current location, at step S101, a position-measuring method determining section checks a position-measuring method specified. When the method specified is a “cell ID position-measuring”, and it is performed, when the method specified is a “base station radio waves position-measuring”; a base station radio waves position-measuring is performed, when the method specified is a “GPS position-measuring” or a “not specified”, at step S102, a judgment of whether an area in which the mobile communication terminal exist is an area suitable for data communication is made. When the judgment is negative, an autonomous GPS position-measuring is performed. When the judgment is affirmative, an assisted GPS position-measuring is performed.

Abstract: A signal simulation device for testing and developing radio receivers adapted to orientate antenna beams to different radio transmitters and to simultaneously suppress interference signals, comprises an antenna array, a signal generator generating reproducible digital signals in the complex baseband, and a digital matrix processor combined and synchronized with the signal generator. The processor has input signals generated by the signal generator and has output signals that form received signals of the antenna array. The input signals of the matrix processor are phase shifted according to a direction of incidence and to relative positions of the elements within the antenna array of the radio receiver, and are combined and supplied to outputs of the matrix processor. Amplitude and phase shift are simulated by weighting of the input signals from the signal generator, the weighting coefficients being calculated on a control computer and input into the matrix processor via an interface.

Abstract: Methods and apparatus are provided for factorized processing of a set of GNSS signal data derived from signals having at least three carriers. A geometry filter is applied to the set of GNSS signal data using a geometry carrier-phase combination to obtain an array of ambiguity estimates for the geometry carrier-phase combination and associated statistical information. A bank of ionosphere filters is applied to the set of GNSS signal data using a geometry-free ionosphere carrier-phase combination to obtain an array of ambiguity estimates for the ionosphere carrier-phase combination and associated statistical information. At least one bank of Quintessence filters is applied to the set of GNSS signal data using a geometry-free and ionosphere-free carrier-phase combination to obtain an array of ambiguity estimates for the geometry-free and ionosphere-free carrier-phase combination and associated statistical information.

Abstract: A method and system for generating beamforming weights for a plurality of antenna elements is disclosed. The invention consists of generating broadened nulls in a direction of arrival corresponding to one or more co-channel interference signals. The broadened nulls permit deviations in the measurement of the direction of arrival or variations therein. The increased information content inherent in generating the broadened nulls is accommodated by postulating the existence of a virtual augmented antenna array comprising the antenna elements of the physical array and a plurality of additional virtual elements. The beamforming weights for the elements of the augmented array are truncated down prior to translation to the size of the physical array and are applied to create the desired broadened nulls and thereby improve system performance.

Abstract: The present invention includes a method for a combined use of a local positioning system, a local RTK system and a regional, wide-area, or global differential carrier-phase positioning system (WADGPS) in which disadvantages associated with the local positioning system, the RTK and the WADGPS navigation techniques when used separately are avoided. The method includes determining a first position of the object based on information from the WADGPS, and determining a second position of the object based on position information from a local positioning/RTK positioning system. Thereafter, position determined by the WADGPS and the position determined by the local positioning/RTK positioning system are compared.

Abstract: A direction finding system is used in which a number of adjacent bands are sequentially measured in fast rotation, with the results from each of the bands being FFT processed to provide amplitude and phase information on all of the signals existing within the band. Upon ascertaining that one wishes to do a direction finding process, one merely accesses the information in the delay memory so that direction finding resources are only allocated to signals of interest and such that one does not have to re-do an FFT upon finding a signal of interest.

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

Abstract: A terminal device searches for a satellite signal by performing a correlation process over a predetermined first accumulation time within a predetermined frequency range in units of search frequencies at specific intervals. When the terminal device has failed in searching for the satellite signal, the terminal device searches for the satellite signal by performing the correlation process over a predetermined second accumulation time longer than the first accumulation time at the search frequency and frequencies differing from the search frequency by a specific frequency which is less than the interval of the search frequencies and specified based on a drift of a reference oscillator of the terminal device within the second accumulation time. The terminal device determines a search result of the satellite signal based on a search result at the search frequency and search results at the frequencies differing from the search frequency by the specific frequency.

Abstract: Navigation signal group delay calibration methods and systems are described. In an embodiment, a code signal generated in a navigation system platform can be measured where the code signal includes timing delay(s). An additional code signal generated in the navigation system platform can be measured where the additional code signal is designated as a timing reference signal. A differential group delay between the code signal and the timing reference signal can the be mathematically estimated in the navigation system platform to correct for an inaccurate position estimation that would result from the timing delay(s).