Abstract: A mobile device may use one or more outlier detectors to detect likelihoods that an outlier condition exists for a satellite positioning system (SPS) position fix. In some implementations, an outlier detector may compare a computed position fix to an element of assistance data to generate an outlier likelihood. A decision to perform a recovery operation may be made based, at least in part, on a generated outlier likelihood. In some implementations, a computed reliability of the position fix may also be considered in making a recovery decision.

Abstract: According to embodiments, a method of logging position data is provided. An indication of a desired accuracy value for determining a geographic position is received. A geographic position is then received. A predicted post-processed accuracy value for the received geographic position is then calculated. The desired accuracy value is then compared with the predicted post-processed accuracy value for the received geographic position. When the predicted post-processed accuracy value for the received geographic position is at least as precise as the desired accuracy value, the geographic position is logged.

Abstract: A system and method for determining a location of a wireless device in a communications network. A request for satellite assistance data may be received from a requesting entity, and a reference location determined as a function of the request. One or more characterizing attributes may be identified as a function of the reference location, and a set of satellites determined as a function of the reference location. It may also be determined whether more than one set of signal measurements should be acquired from one or more satellites in the set of satellites as a function of the identified one or more characterizing attributes. The one or more sets of signal measurements may be acquired, and a location of the wireless device determined from the acquired measurements.

Abstract: The present invention relates to a method and an apparatus for determining an integrity indicating parameter (e.g. an integrity risk IR or a protection level PL) indicating the integrity of positioning information determined from positioning information signals disseminated from a plurality of space vehicles SAT1, SAT2, SAT3 of a global positioning system. An input parameter (e.g. an alert limit AL or an integrity risk IR) is provided, a plurality of integrity information parameters (?SISA, ?SISMA or equivalent, ?X, kX) are received, and the integrity indicating parameter (IR; PL) is determined on the basis of the input parameter (AL; IR) and on the basis of a first relation between the integrity indicating parameter (IR; PL) and the input parameter (AL; IR) and the plurality of integrity information parameters (?SISA, ?SISMA or equivalent, ?X, kX).

Abstract: In a method for providing integrity information for users of a global navigation system, which comprises several space vehicles like satellites transmitting information to a device for position detection, the transmitted information comprises first information from the global navigation system about the accuracy of a signal in space error SISE of a faulty space vehicle, and second information whether or not the global navigation system assesses the faulty space vehicle as faulty. The invention is based on the assumption how exact a fault can be detected, so that performance the global navigation system can be increased; and no unfounded assumption is used which improves the quality of service.

Abstract: The present invention easily evaluates the positioning accuracy by using fewer signal sources.

Abstract: To provide a GPS compound device having a configuration including a GPS receiver, that accurately determines abnormality in an output from the GPS receiver based on a difference between a GPS pseudorange measurement and a Doppler frequency measurement, when detecting the abnormality in the outputs from the GPS receiver, while avoiding continuation of the abnormality at the time of the abnormality determination resulting from estimation errors of the GPS pseudorange measurement and the Doppler frequency measurement. When the abnormality of the outputs from the GPS receiver are detected, an abnormal period is counted. When the count value is below a predetermined threshold, the outputs from the GPS receiver are treated as abnormal, and after it exceeded the threshold, the outputs from the GPS receiver are treated as normal. Thus, the abnormality of the outputs from the GPS receiver can be determined accurately.

Abstract: A method and a system calculates the low probability events for the evaluation of the precision performance of a satellite navigation system, and makes it possible to certify the precision performance of a satellite navigation system for high levels of requirement by modelling events of low probability on the basis of the implementation of the theory of extreme values conjointly with the use of a chart for evaluating precision performance.

Abstract: Method, computer program to implement method, storage medium to store the program and apparatus for computing Signal-in-Space Accuracy (SISA) parameters in a regional or Global Navigation Satellite System (GNSS). The method includes at least of: determining individual Signal-in-Space Error (SISE) vectors; mapping individual SISE vectors to a service area; accumulating empirical sample sets; processing density functions of estimations of accumulated sample sets; individually overbounding density functions in one of an overbounding sense related to the regional or GNSS or in a paired overbounding with excess mass sense; and selecting a worst case according to predefined requirements.

Abstract: According to a first form, the invention relates to a method for monitoring the integrity of position information outputted by a hybridization device that includes a bank (3) of Kalman filters, each filter developing a hybrid navigation solution from inertial measurements calculated by a virtual platform (2) and from raw measurements of signals transmitted by a satellite constellation which are outputted by a global navigation satellite system (GNSS), characterized in that the method consists of the steps, for each satellite of the constellation, of calculating a cross-innovation of the satellite that reflects the deviation between an observation, corresponding to a raw measurement from the satellite, and an a posteriori estimation of said observation that is developed through a Kalman filter and does not use the raw measurement from the satellite; carrying out a statistical test of the cross-innovation to ascertain whether or not the satellite is malfunctioning.

Abstract: A process for increasing the availability of a global navigation system that includes a plurality of spacecraft, each of which transmits information for determining the position of a terminal. From the plurality of spacecraft, a first subset, with at least one spacecraft, and a second subset are determined, the second subset being constituted by those spacecraft that are not included in the first subset. The integrity risk is determined for the information transmitted only by the second spacecraft. The first and the second subsets of spacecraft are determined such that the integrity risk, for information transmitted by the second subset spacecraft minimized relative to the integrity risk for information of all spacecraft included in the plurality of spacecraft.

Abstract: A process for improving continuity in a two-frequency navigation satellite system includes steps of i) observing the ionosphere by measurements in the two or more frequency bands; and ii) transmitting an alert message which informs user systems of a change of the ionosphere when at least one measurement indicates a change of the ionosphere that deviates from one or more predefined conditions.

Abstract: Methods and apparatus for implementing a receiver autonomous integrity monitoring (RAIM) algorithm are provided. The RAIM algorithm is for determining an integrity risk in a global navigation satellite system (GNSS) by processing several ranging signals received from satellites of the GNSS. The algorithm involves determining several integrity risks at an alert limit for different fault conditions of the ranging signals, and determining an overall integrity risk at the alert limit from the determined several integrity risks.

Abstract: A navigation system for detecting error on Doppler frequencies of a plurality of satellite signals measured by the navigation system is disclosed herein. The navigation system includes an offset calculator for calculating offsets of the Doppler frequencies of the satellite signals during a predetermined time period and calculating an average value of the offsets. The navigation system further includes an error detecting unit coupled to the offset calculator. The error detecting unit compares the offsets of the Doppler frequencies of the satellite signals with the average value of the offsets and determines whether the satellite signals are unavailable according to corresponding comparison results.

Abstract: A method for modelling integrity of a filtered global navigation satellite system, by calculating component navigation system error distributions for a set of fault conditions and a fault free condition, and determining overall navigation error distribution by forming a mixture distribution from these component navigation system error distributions. The mixture distribution may be determined by weighted summation of navigation system error (NSE) distributions with weightings determined according to prior probabilities for the fault conditions. Once the overall NSE mixture distribution is determined in this way, it can be used to derive one or more statistical quantities relevant to the integrity of the navigation system such as the probability of exceeding given alert limits in a desired coordinate geometry.

Abstract: A system and method for determining whether a wireless device has transmitted one or more forged satellite measurements. An estimated location of the wireless device may be determined as a function of information from a cellular network. Acquisition assistance data may be determined for a first set of satellites as a function of the estimated location, the assistance data including an uncertainty window. If measured code phase information in the satellite measurements substantially correlates to the uncertainty window, then the wireless device may be transmitting forged satellite measurements.

Abstract: The present disclosure relates to a monitoring system which comprises at least one monitoring satellite placed in orbit at a lower altitude than that of the satellites of the satellite constellation so as to be capable of receiving the positioning signals emitted towards the Earth by said satellites, and which comprises a processing unit intended for verifying the integrity of said received positioning signals, using position information that is separate from said signals for this purpose.

Abstract: A positioning device including: a time counter for counting time; a first reception controller (S1) for intermittently receiving time information from the positioning satellite through a reception unit; a time revising unit (S14) for revising the time counted by the time counter based on the received time information; an error calculator (S12, S13) for calculating an error per unit time (“?/?”) in the time counted by the time counter based on the received time information and the time counted by the time counter; a time correcting unit (S4) for calculating corrected time by removing an error from the time counted by the time counter based on the calculated error per unit time (“?/?”); and a positioning unit (S5 to S8) for acquiring a signal of the positioning satellite by using the corrected time and measuring a position of the positioning device based on the acquired signal.

Abstract: This invention relates to domain of space activity and can be used for the Earth satellite aided radio navigation, particularly, for control (monitoring) the system integrity without attendance of means of the ground control complex and globally allocated reference stations. A technical result of the claimed technical solution is the responsiveness enhancement of a user's notification about navigation signal uncertainty; cutting-down of expenditures for solving the task of system's integrity control considering the lack of globally allocated ground-based control and monitoring complexes; elimination of additional radio links; increase of reliability of the system's integrity control, growth of reliability.

Abstract: The invention relates to a calculation device providing means for estimating an indication of integrity of a satellite navigation system, including a means for estimating in real time, by measuring data calculated by the navigation system, an indication of integrity of the system with respect to very low-probability location errors, the device including a means for receiving data calculated by the location system, a means for estimating a model of distribution of location errors, a means for estimating parameters characterizing the distribution model, a calculation means applying the extreme values theory as a function of the parameters characterizing the distribution model enabling the modeling of the distribution of very low-probability location errors, a means for estimating in real time an indication of integrity for very low-probability location errors, and a means for transmitting in real time an indication of integrity.

Abstract: A multi-constellation GNSS augmentation and assistance system may include a plurality of reference stations. Each reference station may be adapted to receive navigation data from a plurality of different global navigation satellite systems and to monitor integrity and performance data for each different global navigation satellite system. An operation center may receive the integrity and performance data transmitted from each of the plurality of reference stations. A communication network may transmit a message from the operation center to navcom equipment of a user for augmentation and assistance of the navcom equipment.

Abstract: Embodiments of the invention are directed to a method for integrity communication in a satellite navigation system having a space segment with several satellites transmitting navigation signals for reception and evaluation by use systems for position determination, and a ground segment with several observation stations that, in their totality, monitor the satellites and their signals, and including at least one transmitting station.

Abstract: The subject matter disclosed herein relates to a system and method for determining a sufficiency of measurements for locating positions. In one example, although claimed subject matter is not so limited, a process to improve accuracy of pseudorange measurements may be conducted using multiple dwells.

Abstract: Authentication of a signal, signalA, that is provided as having been received from a source at a first global location by comparing it to a signal that is received from the source at a second global location, signalB, where signalB contains an unknown signal that is unique to the source, and determining, that signalA contains the same unknown signal that is contained in signalB.

Abstract: A method of processing global navigation satellite system (GNSS) data includes identifying one or more GNSS satellites servicing a predefined area, receiving at least one of GNSS almanac data or space-based augmentation system (SBAS) data for the satellites servicing the predefined area, determining the performance of the GNSS satellites servicing the predefined area using the almanac data or SBAS data, and applying a performance rating to the predefined area based on the performance of the GNSS satellites.

Abstract: A system and method for detecting one or more forged satellite measurements transmitted from a wireless device. Information may be transmitted to a wireless device, the information including a request that the wireless device provide a portion of a navigation data message from one or more satellites to a location determining system. The one or more satellite measurements and the portion of the navigation data message may be received from the wireless device. The navigation data message may be determined as a function of information from a reference network. The determined navigation data message may then be compared with the received navigation data message portion to thereby determine whether any of the one or more satellite measurements transmitted by the device have been forged.

Abstract: A vertical integrity monitoring method and system are described. The vertical integrity monitoring method includes determining a noise sigma ratio parameter. The method also includes determining two vertical protection limit slopes and an associated covariance matrix. The method further includes determining a vertical integrity limit and set of weights based on the VPL slopes, covariance and the parameter; and applying the set of weights based on the parameter to calculate a vertical solution. An integrity monitoring system may have hardware and/or software embodying the one or more methods described.

Abstract: The present invention relates to a method for protecting a radionavigation receiver user in relation to aberrant pseudo-range measurements. In the method, a measurement error is detected by a statistical estimation scheme based on calculating the residuals of the measurements. This method makes it possible, in particular, in a manner which is autonomous of any ground segment (therefore implementing a RAIM functionality) to boost the performance of an off-the-shelf receiver (termed “primary”) without any integrity function, to detect possible errors contaminating measurements on input to the calculation of the position, through the use of a robust estimation statistical algorithm, that is to say one truly unaffected by measurement errors, and implementing a dynamic criterion, and to calculate a robust correction for the position provided by the primary receiver by excluding such an error if it is detected.

Abstract: Methods and apparatuses are provided that may be implemented in various electronic devices to identify suspect measurements for use in a position/velocity/time estimation filter and provide corresponding validated measurements that may be either operatively re-weighted in some manner or operatively one-sided isolated in some manner when subsequently considered by the position/velocity/time estimation filter.

Abstract: The invention relates to a calculation device providing means for estimating an indication of integrity of a satellite navigation system, including a means for estimating in real time, by measuring data calculated by the navigation system, an indication of integrity of the system with respect to very low-probability location errors, the device including a means for receiving data calculated by the location system, a means for estimating a model of distribution of location errors, a means for estimating parameters characterizing the distribution model, a calculation means applying the extreme values theory as a function of the parameters characterizing the distribution model enabling the modeling of the distribution of very low-probability location errors, a means for estimating in real time an indication of integrity for very low-probability location errors, and a means for transmitting in real time an indication of integrity.

Abstract: A navigation system for detecting error on Doppler frequencies of a plurality of satellite signals measured by the navigation system is disclosed herein. The navigation system includes an offset calculator for calculating offsets of the Doppler frequencies of the satellite signals during a predetermined time period and calculating an average value of the offsets. The navigation system further includes an error detecting unit coupled to the offset calculator. The error detecting unit compares the offsets of the Doppler frequencies of the satellite signals with the average value of the offsets and determines whether the satellite signals are unavailable according to corresponding comparison results.

Abstract: The subject matter disclosed herein relates to a system and method for determining a sufficiency of measurements for locating positions. In one example, although claimed subject matter is not so limited, a process to improve accuracy of pseudorange measurements may be terminated in response to a weighting of quantitative assessments of at least some of such pseudorange measurements.

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: A method for estimating an integrity risk in a satellite navigation system includes receiving a plurality of navigation signals at a user system from at least one satellite, the plurality of navigation signals including data relative to the integrity of the satellite navigation system; and estimating the integrity risk using the data in the at least one user system. The estimating further includes forming a plurality of intervals of an integration variable of an integral function, estimating a maximum of the integrity risk for each interval, comparing the maximum of each interval to find an overall maximum of all the intervals; and using the overall maximum as an estimate of the integrity risk.

Abstract: Systems and methods for detecting global positioning system (GPS) measurement errors are provided. In this regard, a representative system, among others, includes a navigation device that is configured to receive GPS signals from signal sources, the navigation device being configured to calculate pseudoranges (PRs) and delta ranges (DRs) based on the received GPS signals, the navigation device including a consistency check algorithm that is configured to: determine mismatches between the respective calculated PRs and DRs, and indicate that an error exists in the respective calculated PRs and DRs based on their mismatch and mismatch accumulations. This algorithm can be independent of navigation state and is capable of detecting slow-changing errors.

Abstract: In a method for reducing the adverse effect of clock frequency jumps on a user-position determination device in a global navigation system, a plurality of space vehicles each having a clock, transmit position determination information to the position determining device. If a sufficient number of such navigation signals from a first group of space vehicles having clocks in which no jump occurs are available for this purpose, and if a calculated integrity risk is acceptable, position determination is performed using those navigation signals. If not, however, the position determination device receives navigation signals from space vehicles of a second group with clocks in which jumps can occur. The latter signals are combined with signals from the first group in a manner which takes into account possible jumps, and the process is repeated.

Abstract: A system and method for determining whether an estimated location of a wireless device includes one or more forged satellite measurements. An estimated location of the wireless device may be determined from signals received from a first set of satellites, and a set of residuals obtained as a function of the estimated location. The obtained set of residuals may then be compared to a reference set of residuals. If the comparison between the obtained set and reference set of residuals is less than a predetermined threshold, then the estimated location may be identified as having one or more forged satellite measurements.