# Ulrich Vollath, Ismaning DE

## Ulrich Vollath, Ismaning DE

Patent application number | Description | Published |
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20080284643 | Post-mission high accuracy position and orientation system - A method of generating post-mission position and orientation data comprises generating position and orientation data representing positions and orientations of a mobile platform, based on global navigation satellite system (GNSS) data and inertial navigation system (INS) data acquired during a data acquisition period by the mobile platform, using a network real-time kinematic (RTK) subsystem to generate correction data associated with the data acquisition period, and correcting the position and orientation data based on the correction data. The RTK subsystem may implement a virtual reference station (VRS) technique to generate the correction data. | 11-20-2008 |

20090027264 | Gnss Signal Processing Methods and Apparatus - Methods and apparatus for processing of data from a network of GNSS reference stations are presented. An ionosphere-free, federated geometry filter is employed so that computation time increases only linearly with the increase in number of reference stations, significantly reducing processing time as compared to a centralized filter approach. | 01-29-2009 |

20090093959 | REAL-TIME HIGH ACCURACY POSITION AND ORIENTATION SYSTEM - A real-time high accuracy position and orientation system (RT-HAPOS) system for a vehicle, such as an aircraft, comprises a global navigation satellite system (GNSS) receiver disposed on the vehicle and an integrated inertial navigation (IIN) module disposed on the vehicle. The GNSS receiver generates GNSS position data indicating approximate positions of the vehicle during a data acquisition period in which the vehicle is moving. The IIN module executes a real-time kinematic (RTK) algorithm during the data acquisition period to generate output position data indicating positions of the vehicle at a greater precision than the GNSS position data, based on the GNSS position data, inertial measurement data acquired on the vehicle during the data acquisition period, and a set of virtual reference station (VRS) observables received during the data acquisition period from a remote source external to the vehicle, where the VRS observables are based on the GNSS position data. | 04-09-2009 |

20090109090 | POSITION DETERMINATION WITH REFERENCE DATA OUTAGE - Position determination at a rover station on the basis of positioning signals from a plurality of positioning satellites. During normal operation a position of the rover station is determined on the basis of the positioning signal from the positioning satellites and reference data received via a separate connection from a reference station. Upon detecting an outage of the reference data from the reference station, error data at least including satellite clock drifts is obtained from error data transmitter and applied in the determination process in order to eliminate positioning errors introduced by satellite clock drifts that cannot be compensated on the basis of the reference data due to the outage. | 04-30-2009 |

20090135057 | Real-time fast decimeter-level GNSS positioning - Methods and apparatus for processing of data from GNSS receivers are presented. A real-time GNSS rover-engine, a long distance multi baseline averaging (MBA) method, and a stochastic post-processed accuracy predictor are described. | 05-28-2009 |

20090182502 | REFINING A POSITION ESTIMATE OF A LOW EARTH ORBITING SATELLITE - In a method for refining a position estimate of a low earth orbiting (LEO) satellite a first position estimate of a LEO satellite is obtained with a GNSS receiver on-board the LEO satellite. The first position estimate is communicated to a Virtual Reference Station (VRS) processor. VRS corrections are received at the LEO satellite, the VRS corrections having been calculated for the first position estimate by the VRS processor. The VRS corrections are processed on-board the LEO satellite such that a VRS corrected LEO satellite position estimate of the LEO satellite is generated for the first position estimate. | 07-16-2009 |

20090184868 | Fast decimeter-level GNSS positioning - Methods and apparatus for processing of data from GNSS receivers are presented. A post-processing engine and a post-processed accuracy predictor are described. The post-processing engine provides high accuracy GNSS (GPS) position determination with short occupation time for GIS applications. The post-processed accuracy predictor calculates during data collection an estimate of the accuracy likely to be achieved after post-processing. This helps to optimize productivity when collecting GNSS data for which post-processed accuracy is important. The predictor examines the quality of carrier measurements and estimates how well the post-processed float solution will converge in the time since carrier lock was obtained. | 07-23-2009 |

20090184869 | Processing Multi-GNSS data from mixed-type receivers - Computer-implemented methods and apparatus are presented for processing data collected by at least two receivers from multiple satellites of multiple GNSS, where at least one GNSS is FDMA. Data sets are obtained which comprise a first data set from a first receiver and a second data set from a second receiver. The first data set comprises a first FDMA data set and the second data set comprises a second FDMA data set. At least one of a code bias and a phase bias may exist between the first FDMA data set and the second FDMA data set. At least one receiver-type bias is determined, to be applied when the data sets are obtained from receivers of different types. The data sets are processed, based on the at least one receiver-type bias, to estimate carrier floating-point ambiguities. Carrier integer ambiguities are determined from the floating-point ambiguities. The scheme enables GLONASS carrier phase ambiguities to be resolved and used in a combined FDMA/CDMA (e.g., GLONASS/GPS) centimeter-level solution. It is applicable to real-time kinematic (RTK) positioning, high-precision post-processing of positions and network RTK positioning. | 07-23-2009 |

20100079333 | METHOD AND SYSTEM FOR LOCATION-DEPENDENT TIME-SPECIFIC CORRECTION DATA - A method and system for delivery of location-dependent time-specific corrections. In one embodiment, a first extended-lifetime correction for a first region is generated. A distribution timetable is used to determine a first time interval for transmitting the first extended-lifetime correction to the first region. The first extended-lifetime correction is then transmitted via a wireless communication network to said first region in accordance with said distribution timetable. | 04-01-2010 |

20100141515 | POSITION TRACKING DEVICE AND METHOD - The present application relates to tracking a position of a device, e.g. for detecting slow and rapid earth deformation, by making use of a recursive filter having the filter characteristic adapted to a detected type of motion. If the motion of the position tracking device is rapid, the filter characteristic is set such that the rapid motion can be tracked with the necessary speed. On the other hand, if the motion is slow, e.g. during times of a normal tectonic drift, the filter characteristic is set such that the motion is slowly tracked with the advantage of efficient noise reduction, i.e. noise in the input signal is effectively barred and does not pass through the filter to the output signal. Thus, in times of rapid motion the convergence speed of the filter output signal to the input signal is set high for fast convergence and in times of slow motion the convergence speed of the filter output signal to the input signal is set low for a slow convergence. The filter may be a Kalman filter. | 06-10-2010 |

20100169001 | POST-MISSION HIGH ACCURACY POSITION AND ORIENTATION SYSTEM - A method of generating post-mission position and orientation data comprises generating position and orientation data representing positions and orientations of a mobile platform, based on global navigation satellite system (GNSS) data and inertial navigation system (INS) data acquired during a data acquisition period by the mobile platform, using a network real-time kinematic (RTK) subsystem to generate correction data associated with the data acquisition period, and correcting the position and orientation data based on the correction data. The RTK subsystem may implement a virtual reference station (VRS) technique to generate the correction data. | 07-01-2010 |

20100214161 | GNSS moving base positioning - Methods and apparatus are presented for determining a position of an antenna of a GNSS rover from observations of GNSS signals collected at the antenna over multiple epochs and from correction data for at least one of the epochs. A first-epoch rover position relative to a moving base location is determined, a second-epoch update of the first-epoch rover position relative to the moving base location for a second epoch is determined using a single-differenced delta phase process, and the first-epoch position and the second-epoch update are combined to obtain a second-epoch rover position relative to a moving base location of the second epoch. | 08-26-2010 |

20100214162 | GNSS position coasting - Methods and apparatus are presented for determining a position of an antenna of a GNSS rover from observations of GNSS signals collected at the antenna over multiple epochs and from correction data for at least one of the epochs. A first-epoch rover position relative to a base location is determined for a first epoch using a single-differencing process based on one of (i) fixed carrier-phase ambiguities and (ii) a weighted average of carrier-phase ambiguity candidates which is converged to a predetermined threshold. A second-epoch rover position relative to a base location is determined for a second epoch using a single-differencing process. A second-epoch update of the first-epoch rover position relative to the base location is determined for the second epoch using a single-differenced delta phase process and the first-epoch rover position is combined with the second-epoch update to obtain a second-epoch delta phase rover position relative to a moving base location of the second epoch. The second-epoch delta phase rover position is selected as reliable if the second-epoch rover position is not based on one of (i) fixed carrier-phase ambiguities and (ii) a weighted average of carrier-phase ambiguity candidates which is converged to a predetermined threshold. | 08-26-2010 |

20100253575 | GENERALIZED PARTIAL FIXING - Described is a generalized approach for integer parameter estimation, especially in the context of Global Navigation Satellite Systems (GNSS). The problem solved is the case where a definitively correct integer solution cannot be identified for all ambiguity parameters in a reliable way. The proposed solution is to apply a linear transformation to the ambiguities (multiply with a matrix) such that the images of the first and the second candidate (or more) are identical. That way, from the first and second (and possibly more) candidates of the integer least-squares solution, a subset of ambiguity combinations is derived that can be fixed. Thus, it is no longer necessary to choose between the solutions as they coincide for the new ambiguities. The advantage of this approach is maximizing all information still available when finally deriving additional parameters such as position, clock error, atmospheric errors and/or time correlated noise. This technique is applicable to real-time and post-processing applications, as well as to pure GNSS applications, GNSS integrated with other sensors (e.g. INS) and other applications that have to resolve multiple integer ambiguities. This may also apply to optical distance-measurement. GNSS applications include kinematic and static positioning with single base stations as well as with multiple base stations or reference station networks. They also comprise the integer parameter estimation methods used within the reference station network computations. | 10-07-2010 |

20110140959 | GNSS Signal Processing Methods and Apparatus with Ambiguity Selection - Methods and apparatus are provided for estimating parameters, i.e. ambiguities, derived from GNSS signals. Observations of a GNSS signal from each of a plurality of GNSS satellites are obtained ( | 06-16-2011 |

20110148698 | GNSS Signal Processing Methods and Apparatus with Scaling of Quality Measure - Methods and apparatus are provided for estimating parameters, i.e. ambiguities, derived from GNSS signals. Observations of GNSS signals are obtained from each of a plurality of GNSS satellites ( | 06-23-2011 |

20110156949 | GNSS Signal Processing Methods and Apparatus with Tracking Interruption - Methods and apparatus are provided for estimating parameters, i.e. ambiguities, derived from GNSS signals. Observations of each of received frequencies of a GNSS signal from a plurality of GNSS satellites are obtained for a plurality of instances in time ( | 06-30-2011 |

20110260914 | GNSS Signal Processing Methods and Apparatus With Candidate Set Selection - Methods and apparatus are provided for estimating parameters, i.e. ambiguities, derived from GNSS signals. Observations of GNSS signals are obtained from each of a plurality of GNSS satellites ( | 10-27-2011 |

20110267226 | GNSS Signal Processing Methods and Apparatus with Ambiguity Convergence Indication - Methods and apparatus are provided for estimating parameters, i.e. ambiguities, derived from GNSS signals. Observations of a GNSS signal from each of a plurality of GNSS satellites are obtained ( | 11-03-2011 |

20110267228 | GNSS Signal Processing Methods and Apparatus with Geometric Filter - Methods and apparatus are provided for processing a set of GNSS signal data derived from signals of a first set of satellites having at least three carriers and signals of a second set of satellites having two carriers. A geometry filter uses a geometry filter combination to obtain an array of geometry-filter ambiguity estimates for the geometry filter combination and associated statistical information. Ionosphere filters use a two-frequency ionospheric combination to obtain an array of ionosphere-filter ambiguity estimates for the two-frequency ionospheric combinations and associated statistical information. Each two-frequency ionospheric combination comprises a geometry-free two-frequency ionospheric residual carrier-phase combination of observations of a first frequency and observations of a second frequency. Auxiliary ionosphere filters use an auxiliary ionospheric combination to obtain an array of auxiliary-ionosphere-filter ambiguity estimates for the auxiliary ionospheric combinations and associated statistical information. Each auxiliary ionospheric combination uses carrier-phase observations of a third frequency and carrier-phase observations of at least one of the first frequency and the second frequency. A combined array of ambiguity estimates is prepared for all carrier phase observations and associated statistical information by combining the arrays of the geometry filter and the ionosphere filters and the auxiliary ionosphere filters. | 11-03-2011 |

20110279314 | GNSS Signal Processing Methods and Apparatus with Ionospheric Filters - Methods and apparatus are provided for processing a set of GNSS signal data derived from signals of a first set of satellites having at least three carriers and signals of a second set of satellites having two carriers. A geometry filter uses a geometry filter combination to obtain an array of geometry-filter ambiguity estimates for the geometry filter combination and associated statistical information. Ionosphere filters use a two-frequency ionospheric combination to obtain an array of ionosphere-filter ambiguity estimates for the two-frequency ionospheric combinations and associated statistical information. Each two-frequency ionospheric combination comprises a geometry-free two-frequency ionospheric residual carrier-phase combination of observations of a first frequency and observations of a second frequency. Auxiliary ionosphere filters use an auxiliary ionospheric combination to obtain an array of auxiliary-ionosphere-filter ambiguity estimates for the auxiliary ionospheric combinations and associated statistical information. Each auxiliary ionospheric combination uses carrier-phase observations of a third frequency and carrier-phase observations of at least one of the first frequency and the second frequency. A combined array of ambiguity estimates is prepared for all carrier phase observations and associated statistical information by combining the arrays of the geometry filter and the ionosphere filters and the auxiliary ionosphere filters. | 11-17-2011 |

20110285587 | GNSS Surveying Methods and Apparatus - Methods and apparatus are presented for improved productivity in determining static position of an antenna of a GNSS rover, such as in stop-and-go surveying. Computer-implemented methods and apparatus provide for determining a static position of an antenna of a GNSS rover from observations of GNSS signals collected at the antenna over multiple epochs and from correction data for at least one of the epochs. In some forms this comprises: acquiring first-epoch rover observations of GNSS signals received at the antenna during a first epoch, obtaining first-epoch correction data for the first epoch, determining a synchronized rover antenna position for the first epoch from the first-epoch rover observations and the first-epoch correction data, acquiring subsequent-epoch rover observations from the received GNSS satellite signals for at least one subsequent epoch for which correction data is unavailable, determining that the antenna position remained static for at least two static epochs, and determining an updated rover antenna position from the synchronized rover antenna position and the subsequent-epoch rover observations of at least one static epoch of the at least one subsequent epoch. | 11-24-2011 |

20120026038 | GNSS Signal Processing Methods and Apparatus - Methods and apparatus are provided for processing a set of GNSS signal data derived from observations of GNSS signals of multiple transmitters over multiple epochs, the GNSS signals having a first signal and a second signal in a first band which can be tracked as a single wide-band signal and each of which can be tracked separately, comprising: obtaining carrier-phase observations of the first signal, obtaining carrier-phase observations of the second signal, obtaining code observations of the wide-band signal, and estimating from a set of observables comprising the carrier-phase observations of the first signal, the carrier-phase observations of the second signal and the code observations of the wide-band signal values for a set of parameters comprising: position of a receiver of the GNSS signals, clock error of a receiver of the GNSS signals, and an array of ambiguities comprising an ambiguity for each transmitter from which carrier-phase observations of the first signal are obtained and an ambiguity for each transmitter from which carrier-phase observations of the second signal are obtained. | 02-02-2012 |

20120119951 | Global navigation satellite antenna systems and methods - A method for reducing multipath when determining a location of a stationary or near stationary position, includes receiving a signal from an antenna moving continuously with respect to the stationary or near stationary position, the signal including a multipath component, processing the received signal including the multipath component, wherein multipath error in the received signal is reduced during the processing and determining a location of the stationary or near stationary position based on the processed received signal with the multipath error reduced. | 05-17-2012 |

20120146847 | METHOD AND SYSTEM FOR LOCATION-DEPENDENT TIME-SPECIFIC CORRECTION DATA - A method and system for delivery of location-dependent time-specific corrections. In one embodiment, a first extended-lifetime correction for a first region is generated. A distribution timetable is used to determine a first time interval for transmitting the first extended-lifetime correction to the first region. The first extended-lifetime correction is then transmitted via a wireless communication network to said first region in accordance with said distribution timetable. | 06-14-2012 |

20130332072 | REFINING A POSITION ESTIMATE OF A LOW EARTH ORBITING SATELLITE - In a method for refining a position estimate of a low earth orbiting (LEO) satellite a first position estimate of a LEO satellite is generated with a GNSS receiver on-board the LEO satellite. Corrections are received at the LEO satellite. The corrections are processed on-board the LEO satellite such that a corrected LEO satellite position estimate of the LEO satellite is generated for the first position estimate. | 12-12-2013 |

20140028497 | GLOBAL NAVIGATION SATELLITE ANTENNA SYSTEMS AND METHODS - A method for reducing multipath when determining a location of a stationary or near stationary position, includes receiving a signal from an antenna moving continuously with respect to the stationary or near stationary position, the signal including a multipath component, processing the received signal including the multipath component, wherein multipath error in the received signal is reduced during the processing and determining a location of the stationary or near stationary position based on the processed received signal with the multipath error reduced. | 01-30-2014 |