Abstract:
Methods and apparatus are described for processing a set of GNSS signal data derived from code observations and carrier-phase observations at multiple receivers of GNSS signals of multiple satellites over multiple epochs, the GNSS signals having at least two carrier frequencies and a navigation message containing orbit information, comprising: obtaining precise orbit information for each satellite, determining at least one set of ambiguities per receiver, each ambiguity corresponding to one of a receiver-satellite link and a satellite-receiver-satellite link, and using at least the precise orbit information, the ambiguities and the GNSS signal data to estimate a phase-leveled clock per satellite.
Abstract:
Methods and apparatus are described for processing a set of GNSS signal data derived from signals of a set of satellites having carriers observed at a rover antenna, wherein the data includes a carrier observation and a code observation of each carrier of each satellite, comprising: obtaining for each satellite clock corrections comprising at least two of: (i) a code-leveled satellite clock, (ii) a phase-leveled satellite clock, and (iii) a satellite clock bias representing a difference between a code-leveled satellite clock and a phase-leveled satellite clock, running a first filter which uses at least the GNSS signal data and the satellite clock corrections to estimate values for parameters comprising at least one carrier ambiguity for each satellite, and a covariance matrix of the carrier ambiguities, determining from each carrier ambiguity an integer-nature carrier ambiguity comprising one of: an integer value, and a combination of integer candidates, inserting the integer-nature carrier ambiguities as pseudo-observations into a second filter, and applying the second filter to the GNSS signal data and the satellite clock corrections to obtain estimated values for parameters comprising at least the position of the receiver.
Abstract:
Methods and apparatus are described for processing a set of GNSS signal data derived from code observations and carrier-phase observations at multiple receivers of GNSS signals of multiple satellites over multiple epochs, the GNSS signals having at least two carrier frequencies and a navigation message containing orbit information, comprising: obtaining precise orbit information for each satellite, determining at least one set of ambiguities per receiver, each ambiguity corresponding to one of a receiver-satellite link and a satellite-receiver-satellite link, and using at least the precise orbit information, the ambiguities and the GNSS signal data to estimate a phase-leveled clock per satellite.
Abstract:
A method of determining the position of a GNSS receiver antenna includes steps of acquiring input data which includes observations at the GNSS receiver antenna of signals of at least clock and position information of GNSS satellites, for each of a plurality of epochs. Float parameters of a state vector from the input data of each epoch are then estimated. The float parameters include receiver antenna position, receiver clock, and at least one ambiguity per satellite. A jump in the at least one ambiguity of at least one satellite from one epoch to another epoch is detected. Then bridge parameters from the input data of at least one epoch and from the estimated float parameters are estimated. The bridge parameters include values sufficient to update the float parameters to compensate for the jump, and the bridge parameters are then used to update the float parameters.
Abstract:
Methods and apparatus are described for processing a set of GNSS signal data derived from signals of a set of satellites having carriers observed at a rover antenna, wherein the data includes a carrier observation and a code observation of each carrier of each satellite, comprising: obtaining for each satellite clock corrections comprising at least two of: (i) a code-leveled satellite clock, (ii) a phase-leveled satellite clock, and (iii) a satellite clock bias representing a difference between a code-leveled satellite clock and a phase-leveled satellite clock, running a first filter which uses at least the GNSS signal data and the satellite clock corrections to estimate values for parameters comprising at least one carrier ambiguity for each satellite, and a covariance matrix of the carrier ambiguities, determining from each carrier ambiguity an integer-nature carrier ambiguity comprising one of: an integer value, and a combination of integer candidates, inserting the integer-nature carrier ambiguities as pseudo-observations into a second filter, and applying the second filter to the GNSS signal data and the satellite clock corrections to obtain estimated values for parameters comprising at least the position of the receiver.
Abstract:
Methods and apparatus are described for determining position of a rover antenna, comprising: obtaining rover GNSS data derived from code observations and carrier phase observations of GNSS signals of multiple satellites over multiple epochs, obtaining precise satellite data for the satellites, determining a virtual base station location, generating epochs of synthesized base station data using at least the precise satellite data and the virtual base station location, and applying a differential process to at least the rover GNSS data and the synthesized base station data to determine at least rover antenna positions.
Abstract:
Methods and apparatus are described for determining position of a rover antenna, comprising: obtaining rover GNSS data derived from code observations and carrier phase observations of GNSS signals of multiple satellites over multiple epochs, obtaining precise satellite data for the satellites, determining a virtual base station location, generating epochs of synthesized base station data using at least the precise satellite data and the virtual base station location, and applying a differential process to at least the rover GNSS data and the synthesized base station data to determine at least rover antenna positions.