| Patent application number | Description | Published |
|---|
| 20080252517 | METHOD AND APPARATUS FOR LOCATING POSITION OF A GPS DEVICE - A method and apparatus for locating position of a GPS device is described. In one example, a method for provisioning a mobile device with a model for determining a position of the mobile device in at least one geographic area is provided. The method includes obtaining an estimate of the position of the mobile device, forming one or more satellite orbit models from the estimate and a wide area model, and sending the at least one satellite orbit model to the mobile device. The wide area model is formed from measurements from a plurality of satellites of a Global Positioning System, and the measurements are obtained by a plurality of reference stations. | 10-16-2008 |
| 20090009386 | METHOD AND APPARATUS FOR COMBINING MEASUREMENTS AND DETERMINING CLOCK OFFSETS BETWEEN DIFFERENT GLOBAL NAVIGATION SATELLITE SYSTEMS - Method and apparatus for processing satellite signals from a first satellite navigation system and a second satellite navigation system is described. In one example, at least one first pseudorange between a satellite signal receiver and at least one satellite of the first satellite navigation system is measured. At least one second pseudorange between the satellite signal receiver and at least one satellite of the second satellite navigation system is measured. A first difference between a first time reference frame of the first satellite navigation system and a time reference and a second difference between a second time reference frame of the second satellite navigation system and the time reference are obtained. The at least one first pseudorange and the at least one second pseudorange are combined using the first and second differences in time references. | 01-08-2009 |
| 20090066576 | METHOD AND APPARATUS FOR GENERATING AND USING A REGIONAL-TERRAIN MODEL - A method and apparatus for computing position using a regional-terrain model is provided. The method includes obtaining from at least three satellites pseudorange measurements, computing a transitional position by using a default altitude with a large uncertainty, using this transitional position to obtain from a terrain model altitude information associated with a region, and computing an accurate three-dimensional position as a function of the pseudorange measurements and the altitude information. The region defines a boundary, and the boundary includes the transitional position. | 03-12-2009 |
| 20090174598 | METHOD AND APPARATUS FOR VALIDATING A POSITION IN A SATELLITE POSITIONING SYSTEM USING RANGE-RATE MEASUREMENTS - Method and apparatus for validating an initial position in a satellite positioning system using range-rate measurements is described. In one example, range-rate measurements are obtained at the remote receiver with respect to a plurality of satellites. Expected range-rates are computed with respect to the plurality of satellites using the initial position. Single differences are computed using the range-rate measurements. Expected single differences are computed using the expected range-rates. Single difference residuals are computed between the single differences and the expected single differences. The single difference residuals are compared to a threshold. The initial position may be deemed valid if the absolute value of each of the single difference residuals is less than or equal to the threshold. A valid initial position may be used to fix the pseudorange integers. | 07-09-2009 |
| 20090201196 | METHOD AND APPARATUS FOR GENERATING AND DISTRIBUTING SATELLITE TRACKING INFORMATION - A method and apparatus for generating and distributing satellite tracking data to a remote receiver is disclosed. The method for includes extracting from satellite-tracking data initial model parameters representing a current orbit of at least one satellite-positioning-system satellite, computing an orbit model using the initial model parameters, wherein a duration of the orbit model is longer than a duration of the satellite-tracking data, comparing, for an overlapping period of time, the orbit model to the satellite-tracking data; and adjusting the orbit model to match the satellite tracking data for the overlapping period of time so as to form an adjusted orbit model. The adjusted orbit model comprises the long-term-satellite-tracking data. | 08-13-2009 |
| 20090219203 | METHOD AND APPARATUS FOR COMBINING MEASUREMENTS AND DETERMINING CLOCK OFFSETS BETWEEN DIFFERENT GLOBAL NAVIGATION SATELLITE SYSTEMS - Method and apparatus for processing satellite signals from a first satellite navigation system and a second satellite navigation system is described. In one example, at least one first pseudorange between a satellite signal receiver and at least one satellite of the first satellite navigation system is measured. At least one second pseudorange between the satellite signal receiver and at least one satellite of the second satellite navigation system is measured. A first difference between a first time reference frame of the first satellite navigation system and a time reference and a second difference between a second time reference frame of the second satellite navigation system and the time reference are obtained. The at least one first pseudorange and the at least one second pseudorange are combined using the first and second differences in time references. | 09-03-2009 |
| 20090231192 | METHOD AND SYSTEM FOR GENERATING TEMPORARY EPHEMERIS - Aspects of a method and system for generating temporary ephemeris may include determining one or more positions of a satellite receiver based on a plurality of satellite signals received from a plurality of satellites for which complete ephemeris data has been received at the satellite receiver. Temporary ephemeris data may be generated from the determined one or more positions of the satellite receiver and one or more satellite signals from one or more satellites with incomplete ephemeris data. One or more estimated positions of the satellite receiver may be determined based on the generated temporary ephemeris and a second plurality of satellite signals, wherein at least one of the second plurality of satellite signals is associated with the one or more satellites with incomplete ephemeris data. The temporary ephemeris data may be generated by generating a translated satellite position and a rate of change of an associated receiver clock corrected pseudorange. | 09-17-2009 |
| 20090267833 | METHOD AND APPARATUS FOR LOCATING MOBILE RECEIVERS USING A WIDE AREA REFERENCE NETWORK FOR PROPAGATING EPHEMERIS - A method and apparatus for distribution and delivery of global positioning system (GPS) satellite telemetry data using a communication link between a central site and a mobile GPS receiver. The central site is coupled to a network of reference satellite receivers that send telemetry data from all satellites to the central site. The mobile GPS receiver uses the delivered telemetry data to aid its acquisition of the GPS satellite signal. The availability of the satellite telemetry data enhances the mobile receiver's signal reception sensitivity. | 10-29-2009 |
| 20090304051 | METHOD AND APPARATUS FOR REDUCING THE TIME REQUIRED TO ACQUIRE A GPS SIGNAL - A method of correlating a digital communications signal is described. In an example, a window is defined equal to a portion of an epoch of the digital communication signal. The digital communication signal is then correlated across the window. A determination is made as to whether a correlation peak results from the correlating. Timing parameters are then established for receiving additional digital communication signals in response to presence of the correlation peak. | 12-10-2009 |
| 20090309794 | METHOD AND APPARATUS FOR ENHANCED AUTONOMOUS GPS - Method and apparatus for locating position of a remote receiver is described. In one example, long term satellite tracking data is obtained at a remote receiver. Satellite positioning system (SPS) satellites are detected. Pseudoranges are determined from the remote receiver to the detected SPS satellites. Position of the remote receiver is computed using the pseudoranges and the long term satellite tracking data. SPS satellites may be detected using at least one of acquisition assistance data computed using a previously computed position and a blind search. Use of long term satellite tracking data obviates the need for the remote receiver to decode ephemeris from the satellites. In addition, position of the remote receiver is computed without obtaining an initial position estimate from a server or network. | 12-17-2009 |
| 20090315770 | METHOD AND APPARATUS FOR PROCESSING SATELLITE SIGNALS AT A SATELLITE POSITIONING SYSTEM RECEIVER - Method and apparatus for processing satellite signals in an SPS receiver is described. In one example, the satellite signals are correlated against pseudorandom reference codes to produce correlation results. A determination is made whether the SPS receiver is in a motion condition or a stationary condition. The correlation results are coherently integrated in accordance with a coherent integration period. The coherent integration period is a value that depends upon the motion condition of the SPS receiver. | 12-24-2009 |
| 20100019960 | Method and Apparatus for Mitigating Multipath Effects at a Satellite Signal Receiver Using a Sequential Estimation Filter - A method and apparatus for mitigating multipath effects in a satellite signal receiver is described. In one example, measured pseudoranges are obtained from the satellite signal receiver to a plurality of satellites. For each measured pseudorange: an expected pseudorange is derived from a sequential estimation filter in the satellite signal receiver. The measured pseudorange and the expected pseudorange are differenced to compute a pseudorange residual. The measured pseudorange is applied to the sequential estimation filter only if the pseudorange residual is within a window. | 01-28-2010 |
| 20100066601 | METHOD AND SYSTEM FOR DETERMINING TIME IN A SATELLITE POSITIONING SYSTEM - Method and apparatus for receiving an estimate of time in a satellite signal receiver receives an estimate of time from a server and compensates for error of a clock in the satellite signal receiver using the estimate of time. The output of the compensated clock is used when computing a position of the satellite signal receiver. The estimate of time is received using a network time protocol (NTP), a simple network time protocol (SNTP), or by one-way broadcast from the server. | 03-18-2010 |
| 20100066607 | METHOD AND APPARATUS FOR PROCESSING SATELLITE SIGNALS AT A SATELLITE POSITIONING SYSTEM RECEIVER - Method and apparatus for processing satellite signals in an SPS receiver is described. In one example, the satellite signals are correlated against pseudorandom reference codes to produce correlation results. A determination is made whether the SPS receiver is in a motion condition or a stationary condition. The correlation results are coherently integrated in accordance with a coherent integration period. The coherent integration period is a value that depends upon the motion condition of the SPS receiver. | 03-18-2010 |
| 20100103039 | METHOD AND APPARATUS FOR COMBINING MEASUREMENTS AND DETERMINING CLOCK OFFSETS BETWEEN DIFFERENT SATELLITE POSITIONING SYSTEMS - Method and apparatus for processing satellite signals from a first satellite navigation system and a second satellite navigation system is described. In one example, at least one first pseudorange between a satellite signal receiver and at least one satellite of the first satellite navigation system is measured. At least one second pseudorange between the satellite signal receiver and at least one satellite of the second satellite navigation system is measured. A difference between a first time reference frame of the first satellite navigation system and a second time reference frame of the second satellite navigation system is obtained. The at least one first pseudorange and the at least one second pseudorange are combined using the difference in time references. | 04-29-2010 |
| 20100117900 | METHOD AND SYSTEM FOR MAINTAINING A GNSS RECEIVER IN A HOT-START STATE - Aspects of a method and system for maintaining a GNSS receiver in a hot-start state are provided. A GNSS receiver in a standby mode may transition from a sleep state to a wakeup state to acquire ephemeris from, for example, GPS signals, GALILEO signals, and/or GLONASS signals. The acquired ephemeris may be stored and utilized for the GNSS receiver to generate a navigation solution in a normal mode. The GNSS receiver may transition from the normal mode to the sleep state or the wakeup state in standby mode. A sleep period and a wakeup period for the full sleep-wakeup cycle in the standby mode may be predetermined or dynamically adjusted based on required QoS, quality of satellite signals, and/or user inputs. The sleep period and the wakeup period may be selected in a way to ensure a valid and complete ephemeris to be acquired. | 05-13-2010 |
| 20100134353 | METHOD AND SYSTEM FOR EXTENDING THE USABILITY PERIOD OF LONG TERM ORBIT (LTO) - Aspects of a method and system for extending the usability period of long term orbit (LTO) are provided. A GPS enabled handset may receive LTO data from an AGPS server via a wireless communication network such as 3GPP or WiMAX. The GPS enabled handset may be enabled to receive broadcast GPS signals. The GPS enabled handset may extract navigation information from the received broadcast GPS signals to be used to adjust the received LTO data. The usability period of the received LTO data may be extended, accordingly. A clock model and a satellite health model associated with the extracted navigation information may be used to update or replace the clock model and/or the satellite health model of the received LTO data, respectively. A navigation solution for the GPS enabled handset may be determined more accurately based on the adjusted LTO data. | 06-03-2010 |
| 20100145616 | COMPUTING LONG TERM ORBIT AND CLOCK MODELS WITH VARIABLE TIME-HORIZONS - A method and apparatus for determining long term orbit (LTO) models using variable time-horizons to improve the orbit and clock model accuracy. The method and apparatus use either historic ephemeris or historic measurements for at least one satellite to produce an orbit parameter prediction model (an LTO model). The parameter predicted by the model is compared to an orbit parameter of a current broadcast ephemeris. The result of the comparison (an indicia of accuracy for the model) is used to establish a time-horizon for the orbit parameter prediction model for that particular satellite. Such a time-horizon may be established in this manner for each satellite within a satellite constellation. | 06-10-2010 |
| 20100156705 | METHOD AND APPARATUS FOR DETERMINING ABSOLUTE TIME-OF-DAY IN A MOBILE-ASSISTED SATELLITE POSITIONING SYSTEM - A method and apparatus for determining time-of-day in a mobile receiver is described. In one example, expected pseudoranges to a plurality of satellites are obtained. The expected pseudoranges are based on an initial position of the mobile receiver and an initial time-of-day. Expected line-of-sight data to said plurality of satellites is also obtained. Pseudoranges from said mobile receiver to said plurality of satellites are measured. Update data for the initial time-of-day is computed using a mathematical model relating the pseudoranges, the expected pseudoranges, and the expected line-of-sight data. The expected pseudoranges and the expected line-of-sight data may be obtained from acquisition assistance data transmitted to the mobile receiver by a server. Alternatively, the expected pseudoranges may be obtained from acquisition assistance data, and the expected line-of-sight data may be computed by the mobile receiver using stored satellite trajectory data, such as almanac data. | 06-24-2010 |
| 20100156714 | METHOD AND APPARATUS FOR MONITORING THE INTEGRITY OF SATELLITE TRACKING DATA USED BY A REMOTE RECEIVER - A method and apparatus for monitoring the integrity of satellite tracking data used by a remote receiver is described. In one example, a first set of satellite tracking data is received at a server. Integrity data for a second set of satellite tracking data is generated using the first set of satellite tracking data. The integrity data is then transmitted to at least one remote receiver having the second set of satellite tracking data. | 06-24-2010 |
| 20100235094 | Method And Apparatus For Generating And Using A Regional-Terrain Model - A method and apparatus for computing position using a regional-terrain model is provided. The method includes obtaining from at least three satellites pseudorange measurements, computing a transitional position by using a default altitude with a large uncertainty, using this transitional position to obtain from a terrain model altitude information associated with a region, and computing an accurate three-dimensional position as a function of the pseudorange measurements and the altitude information. The region defines a boundary, and the boundary includes the transitional position. | 09-16-2010 |
| 20100321236 | METHOD AND SYSTEM FOR A GNSS RECEIVER WITH SELF-ASSISTED EPHEMERIS EXTENSIONS - A GNSS enabled mobile device receives GNSS signals from visible GNSS satellites. Broadcast ephemeris is extracted from the received GNSS signals for generating ephemeris extension (future ephemeris) in the next several days for each of the visible GNSS satellites. The GNSS enabled mobile device uses the generated future ephemeris to determine a position fix even without fresh broadcast ephemeris completely received from the visible GNSS satellites. The generation of future ephemeris is scheduled according to the age of available ephemeris extensions and/or the time of visibility. Available ephemeris such as extracted broadcast ephemeris are integrated into an orbit model using the multi-step numerical integration methods and propagated to generate future ephemeris. The generated future ephemeris is reformatted into a desired orbit model and/or format of the GNSS enabled mobile device. A curve fitting polynomial of generated future ephemeris is stored instead of actual generated future ephemeris to conserve storage space. | 12-23-2010 |
| 20110133985 | METHOD AND APPARATUS FOR MAINTAINING INTEGRITY OF LONG-TERM ORBITS IN A REMOTE RECEIVER - A method and apparatus for maintaining integrity of long-term-orbit information used by a Global-Navigation-Satellite-System or other positioning receiver is described. The method comprises obtaining a predicted pseudorange from a first set of long-term-orbit information possessed by a positioning receiver; obtaining, at the positioning receiver from at least one satellite, a measured pseudorange; determining validity of the predicted pseudorange as a function of the predicted pseudorange and the measured pseudorange; and excluding from the long-term-orbit information at least a portion thereof when the validity of the predicted pseudorange is deemed invalid. Optionally, the method may comprise updating or otherwise supplementing the long-term-orbit information with other orbit information if the validity of the predicted pseudorange is deemed invalid. | 06-09-2011 |
| 20110148700 | METHOD AND SYSTEM FOR MOBILE DEVICE BASED GNSS POSITION COMPUTATION WITHOUT EPHEMERIS DATA - A GNSS enabled mobile device receives GNSS assistance data comprising acquisition assistance data, from an A-GNSS server and calculates a relative GNSS position using the receive acquisition assistance data and a local code delay measurement, without using ephemeris data. The received GNSS assistance data comprises an approximate position, acquisition assistance data, satellite almanac data, and/or satellite azimuth and elevation fields, but no ephemeris data. The A-GNSS server calculates corresponding acquisition assistance data at a current time instant and/or one or more future time instants for the approximate position. The satellite azimuth and elevation fields are calculated using local GNSS measurements together with the acquisition assistance data in the received GNSS assistance data are used to calculate the relative GNSS position, which is added to the approximate position to generate an actual GNSS position. | 06-23-2011 |
