A method, apparatus and computer program product monitor the quality of correction data. In a method, first parameter(s) associated with a navigation satellite or propagation of signals transmitted by the navigation satellite are predicted based upon prior data including prior correction data associated with the navigation satellite or the propagation of signals transmitted thereby. The method derives second parameter(s) associated with the navigation satellite or the propagation of signals transmitted thereby based upon second data including second correction data associated with the navigation satellite or the propagation of signals transmitted thereby. The second data including the second correction data is more recent than the prior data including the prior correction data. The method compares the first parameter(s) to the second parameter(s) and, based on the comparing, generates or provides information regarding the quality of the correction data.

A Real-Time Kinematic (RTK) solution is provided to mobile devices having multi-constellation, multi-frequency (MCMF) functionality, in which a single base station may have a baseline much farther than traditional base station. To enable this, embodiments account for differences in atmospheric effects between the rover station and base station when determining a GNSS position fix for a mobile device (rover station), allowing for a separate tropospheric delay error for a base station to be determined. Embodiments may use additional satellite measurements for which no RTK correction is available, and may further use orbital clock correction for these additional satellite measurements.

A Real-Time Kinematic (RTK) solution is provided to mobile devices having multi-constellation, multi-frequency (MCMF) functionality, in which a single base station may have a baseline much farther than traditional base station and where the high accuracy positioning is achieved in a relatively short period of time. To enable this, embodiments involve modeling of an ionosphere-free carrier phase corresponding to combinations of at least three signals received from one or more satellites. The modeling retains the integer nature of carrier phase ambiguities, thereby allowing for fast convergence in determining the integer ambiguity of the carrier phases.

A method for operating a correction service system (CSS), for a satellite navigation system (SNS), having reference-stations (RS) (in a coordinate-system (CS)) having known/fixed coordinates, the RS being operated to receive satellite signals, at least one correction-value (CV) being predefined as a function of the signals received by the selected RS and its coordinates, and is provided to user-devices of the SNS, the at least one CV being checked for plausibility. The CSS divides the CS into multiple-regions, in which user-devices determine an individual position as a function of the plausibility of the received CV, at least one specific-region being selected as a function of the plausibility of the CV, the specific-region(s) being assigned the at least one CV, at least one information-packet being generated, which contains indications about the plausibility of the CV and the specific-region(s), the information-packet(s) being provided to at least one selected group of user-devices.

A Real-Time Kinematic (RTK) solution is provided to mobile devices having multi-constellation, multi-frequency (MCMF) functionality, in which a single base station may have a baseline much farther than traditional base station. To enable this, embodiments account for differences in atmospheric effects between the rover station and base station when determining a GNSS position fix for a mobile device (rover station), allowing for a separate tropospheric delay error for a base station to be determined. Embodiments may use additional satellite measurements for which no RTK correction is available, and may further use orbital clock correction for these additional satellite measurements.

Systems, methods, and apparatuses are provided for compensating for ionospheric delay in multi constellation Global Navigation Satellite Systems (GNSSs). In one method, a single Radio Frequency (RF) path receiver receives a first signal at a first frequency from a first satellite in a first GNSS constellation, receives a second signal at a second frequency from a second satellite in a second GNSS constellation, and calculates the ionospheric delay using the received first signal and the received second signal.

Methods and systems are provided for locating a vehicle. A locating device receives position data and determines an approximate position of the vehicle. A remote server reports a plurality of corrections factor for a respective plurality of locations which are buffered by a transmission server into a burst transmission. The transmission server transmits the burst transmission of the correction factors over a wireless data channel. A receiver receives the burst transmission from the transmission server and a correction device extracts a selected correction factor from the burst transmission based on the approximate position to determine a refined position of the vehicle.

A system or method for generating GNSS corrections can include receiving satellite observations associated with a set of satellites at a reference station, determining atmospheric corrections valid within a geographical area; wherein geographical areas associated with different atmospheric corrections can be overlapping, and wherein the atmospheric corrections can be provided to a GNSS receiver when the locality of the GNSS receiver is within a transmission region of the geographical area.

A reinforcement information adjustment unit reduces an amount of information in reinforcement information by combining: update cycle adjustment processing to set an update cycle of the reinforcement information to be an integer multiple of a predetermined update cycle; geographic interval error value adjustment processing to reduce the number of geographic interval error values by selecting from among a plurality of the geographic interval error values each of which is an error at every predetermined geographic interval out of a plurality of error values, a geographic interval error value at every geographic interval that is an integer multiple of the predetermined geographic interval; and bit count adjustment processing to reduce a bit count of the error value for each error value. A reinforcement information output unit outputs, to an output destination, reinforcement information after being reduced in the amount of information by the reinforcement information adjustment unit.

A system to mitigate errors in GPS corrections and ephemeris uncertainty data broadcast to a vehicle is presented. The system includes reference receivers in a first ground subsystem and a processor. The processor: receives, from reference receivers in a wide area network of reference receivers, satellite measurement data for a first plurality of satellites and receives, from the reference receivers in the first ground subsystem, satellite measurement data and ephemeris data from a second plurality of satellites; evaluate the satellite measurement data to determine if the GPS corrections are degraded by a current ionosphere disturbance activity; determine a current quality metric of the ionosphere; adjust a Vertical Ionosphere Gradient standard deviation sigma-vig; evaluate the ephemeris data to determine if the GPS corrections provided to the vehicle are degraded by ephemeris errors; and establish ephemeris uncertainty to protect integrity based on the evaluation of the ephemeris data.