Abstract: A receiver-side device for use in a satellite-based navigation system comprises a satellite receiver circuit for receiving signals from at least one satellite of the satellite-based navigation system, a communication interface for requesting and receiving data from a communication network, and at least one processing module.

Abstract: A navigation satellite system, one or more NSS reference station is set out for providing information to one or more rover receivers. The NSS reference station comprises a processing unit configured to determine one or more first range intervals representing first ambiguity windows based on estimated atmospheric effects, and determine one or more second range intervals representing a second ambiguity window smaller than each of the first ambiguity windows based on uncertainties of range measurements within a predetermined previous period. The NSS reference station further comprises a transmission unit configured to transmit, to the NSS rover receivers, first messages each comprising a modulo a first ambiguity window, and transmission of two first messages, to range measurement transmit between the NSS rover receiver, a plurality of second messages, each second message comprising a range measurement modulo one of the second ambiguity windows.

Abstract: A correction message for regional GNSS data includes at least one network message and at least one cluster message. The at least one network message relates to stations of a network of stations within a region. The at least one cluster message relates to a subset of stations within the region. Network elements are extracted from the network message and cluster elements are extracted from the cluster message. Network elements and cluster elements are used to determine a position of a rover within the region.

Abstract: A navigation satellite system, one or more NSS reference station is set out for providing information to one or more rover receivers. The NSS reference station comprises a processing unit configured to determine one or more first range intervals representing first ambiguity windows based on estimated atmospheric effects, and determine one or more second range intervals representing a second ambiguity window smaller than each of the first ambiguity windows based on uncertainties of range measurements within a predetermined previous period. The NSS reference station further comprises a transmission unit configured to transmit, to the NSS rover receivers, first messages each comprising a modulo a first ambiguity window, and transmission of two first messages, to range measurement transmit between the NSS rover receiver, a plurality of second messages, each second message comprising a range measurement modulo one of the second ambiguity windows.

Abstract: A navigation satellite system, one or more NSS reference station is set out for providing information to one or more rover receivers. The NSS reference station comprises a processing unit configured to determine one or more first range intervals representing first ambiguity windows based on estimated atmospheric effects, and determine one or more second range intervals representing a second ambiguity window smaller than each of the first ambiguity windows based on uncertainties of range measurements within a predetermined previous period. The NSS reference station further comprises a transmission unit configured to transmit, to the NSS rover receivers, first messages each comprising a modulo a first ambiguity window, and transmission of two first messages, to range measurement transmit between the NSS rover receiver, a plurality of second messages, each second message comprising a range measurement modulo one of the second ambiguity windows.

Abstract: A correction message for regional GNSS data includes data from several stations in a network. The correction message has at least one cluster message. The cluster message contains cluster elements relating to a subset of GNSS stations.

Abstract: Methods and apparatus for processing of GNSS data derived from multi-frequency code and carrier observations are presented which make available correction data for use by a rover located within the region, the correction data comprising: the ionospheric delay over the region, the tropospheric delay over the region, the phase-leveled geometric correction per satellite, and the at least one code bias per satellite. In some embodiments the correction data includes an ionospheric phase bias per satellite. Methods and apparatus for determining a precise position of a rover located within a region are presented in which a GNSS receiver is operated to obtain multi-frequency code and carrier observations and correction data, to create rover corrections from the correction data, and to determine a precise rover position using the rover observations and the rover corrections.

Abstract: A method of communicating corrections for information related to satellite signals among global navigation satellite system (GNSS) receivers is described. The method includes at a first GNSS device determining a component of position of a satellite. The component is then divided by a first value to thereby obtain an integer value and a remainder value, and the only the remainder value is transmitted from the first GNSS device to the second GNSS device. Knowing the first value, the second GNSS device calculates the component of position.

Abstract: A navigation satellite system, one or more NSS reference station is set out for providing information to one or more rover receivers. The NSS reference station comprises a processing unit configured to determine one or more first range intervals representing first ambiguity windows based on estimated atmospheric effects, and determine one or more second range intervals representing a second ambiguity window smaller than each of the first ambiguity windows based on uncertainties of range measurements within a predetermined previous period. The NSS reference station further comprises a transmission unit configured to transmit, to the NSS rover receivers, first messages each comprising a modulo a first ambiguity window, and transmission of two first messages, to range measurement transmit between the NSS rover receiver, a plurality of second messages, each second message comprising a range measurement modulo one of the second ambiguity windows.

Abstract: Methods and apparatus for processing of GNSS data derived from multi-frequency code and carrier observations are presented which make available correction data for use by a rover located within the region, the correction data comprising: the ionospheric delay over the region, the tropospheric delay over the region, the phase-leveled geometric correction per satellite, and the at least one code bias per satellite. In some embodiments the correction data includes an ionospheric phase bias per satellite. Methods and apparatus for determining a precise position of a rover located within a region are presented in which a GNSS receiver is operated to obtain multi-frequency code and carrier observations and correction data, to create rover corrections from the correction data, and to determine a precise rover position using the rover observations and the rover corrections.

Abstract: Methods and apparatus for processing of GNSS data derived from multi-frequency code and carrier observations are presented which make available correction data for use by a rover located within the region, the correction data comprising: the ionospheric delay over the region, the tropospher?c delay over the region, the phase-leveled geometric correction per satellite, and the at least one code bias per satellite. In some embodiments the correction data includes an ionospheric phase bias per satellite. Methods and apparatus for determining a precise position of a rover located within a region are presented in which a GNSS receiver is operated to obtain multi-frequency code and carrier observations and correction data, to create rover corrections from the correction data, and to determine a precise rover position using the rover observations and the rover corrections.

Abstract: In a method of Global Navigation Satellite System (GNSS) reference station integrity monitoring, network Real Time Kinematic (RTK) information is accessed for a location associated with a GNSS reference station. At least one aspect of GNSS information local to the location of the GNSS reference station is compared with a corresponding aspect of the network RTK information. The results of the comparing are monitored for indication of occurrence of compromise to operational integrity of the GNSS reference station.

Abstract: A method of communicating satellite tracking information among a network of global navigation satellite system receivers is described. The method includes determining at a first GNSS receiver which satellites in a constellation of satellites have been continuously tracked over a preceding selected time period, and for each such satellite determining its elevation with respect to the zenith. Only the elevation value for the lowest satellite in the set of satellites for which all satellites of higher elevation values have been continuously tracked over the selected time period is then transmitted to the second GNSS receiver. That receiver can then reconstruct the set of satellites which have been continuously tracked.

Abstract: Methods and apparatus for processing of GNSS data derived from multi-frequency code and carrier observations are presented which make available correction data for use by a rover located within the region, the correction data comprising: the ionospheric delay over the region, the tropospheric delay over the region, the phase-leveled geometric correction per satellite, and the at least one code bias per satellite. In some embodiments the correction data includes an ionospheric phase bias per satellite. Methods and apparatus for determining a precise position of a rover located within a region are presented in which a GNSS receiver is operated to obtain multi-frequency code and carrier observations and correction data, to create rover corrections from the correction data, and to determine a precise rover position using the rover observations and the rover corrections.

Abstract: Methods and apparatus for processing of GNSS data derived from multi-frequency code and carrier observations are presented which make available correction data for use by a rover located within the region, the correction data comprising: the ionospheric delay over the region, the tropospheric delay over the region, the phase-leveled geometric correction per satellite, and the at least one code bias per satellite. In some embodiments the correction data includes an ionospheric phase bias per satellite. Methods and apparatus for determining a precise position of a rover located within a region are presented in which a GNSS receiver is operated to obtain multi-frequency code and carrier observations and correction data, to create rover corrections from the correction data, and to determine a precise rover position using the rover observations and the rover corrections.

Abstract: Methods and apparatus for processing of GNSS data derived from multi-frequency code and carrier observations are presented which make available correction data for use by a rover located within the region, the correction data comprising: the ionospheric delay over the region, the tropospher?c delay over the region, the phase-leveled geometric correction per satellite, and the at least one code bias per satellite. In some embodiments the correction data includes an ionospheric phase bias per satellite. Methods and apparatus for determining a precise position of a rover located within a region are presented in which a GNSS receiver is operated to obtain multi-frequency code and carrier observations and correction data, to create rover corrections from the correction data, and to determine a precise rover position using the rover observations and the rover corrections.

Abstract: A method in a Global Navigation Satellite System (GNSS) receiver for double-nudged broadcast orbit drift correction. A first broadcast orbit message is utilized to nudge a broadcast orbit in use at the GNSS receiver to create a first nudged broadcast orbit for a GNSS satellite, the first nudged broadcast orbit being more precise than the broadcast orbit. A second broadcast orbit message is utilized to nudge the first nudged broadcast orbit in use at the GNSS receiver to create a double-nudged broadcast orbit for a GNSS satellite, the double-nudged broadcast orbit being more precise than the first nudged broadcast orbit. A third broadcast orbit message is utilized to maintain the double-nudged broadcast orbit, the third broadcast orbit message smaller than the second and the first broadcast orbit messages.

Abstract: In a method of Global Navigation Satellite System (GNSS) reference station integrity monitoring, network Real Time Kinematic (RTK) information is accessed for a location associated with a GNSS reference station. At least one aspect of GNSS information local to the location of the GNSS reference station is compared with a corresponding aspect of the network RTK information. The results of the comparing are monitored for indication of occurrence of compromise to operational integrity of the GNSS reference station.

Abstract: A method of communicating corrections for information related to satellite signals among global navigation satellite system (GNSS) receivers is described. An ionosphere correction for ionosphere signal path delay is determined for a first satellite. This ionosphere correction is then compared to an ionosphere correction for ionosphere signal path delay for a satellite assumed to be directly over the receiver. The receiver then sends a message which includes only the difference between the ionosphere correction for the actual observation and the ionosphere correction for a satellite assumed to be at the zenith.

Abstract: A format for providing messages among GNSS apparatus includes providing a message identification block and a message body. The message identification block includes information specifying a message length and a message type block specifying a message type. Rather than sending all data from one apparatus to another, ambiguous observation data is sent to conserve bandwidth. At the sender a deconstruction of GNSS code and carrier observations using knowledge of the signal structure and constellation geometry, together with simplifications of atmospheric models, allows removal from the observation data of that information which can be implicitly understood or recreated by the recipient. This enables only the necessary information to be packed for transmission to the recipient.