A method of analyzing a ground-based augmentation system (GBAS) signal, comprising: transmitting at least one GBAS message burst; receiving the GBAS message burst, and performing a power measurement at symbol times of the GBAS message burst. Further, a test system for testing a ground-based augmentation system is described.

A system and method for determining a receiver position can include determining a receiver position based on a set of satellite observations, determining the receiver position based on sensor measurements, determining a satellite observation discontinuity; based on the satellite observation discontinuity, determining a second receiver position.

The present invention relates to a system for improving accuracy and safety of UAV navigation, and for generating an optimal protection level and geometry screening, and more particularly to a system that monitors an error and a failure of a GNSS navigation signal, broadcasts error correction information and integrity information to a UAV within a radius of about 20 km to allow the UAV to apply the corresponding information by a ground module, thereby improving the navigation accuracy and safety of the UAV. The ground module receives a GNSS navigation signal, calculates GNSS navigation error information, and generates correction information, and monitors a failure through a simplified failure monitoring algorithm, and the mounted module provides a system and a method for receiving a message that is broadcast by the ground module, and calculating precise and safe navigation information of an UAV by applying the message.

Differential ranging measurements are formed using first ranging measurements from reference GNSS receivers and second ranging measurements from GNSS receivers on a rover, the first and second ranging measurements received from a plurality of GNSS satellites. A main navigation solution and a main protection level (PL) set are computed based on the differential ranging measurements. Ionospheric threat scenarios associated with experiencing severe ionospheric gradients to one or more of the plurality of GNSS satellites are determined. A supplemental navigation solution and a corresponding supplemental PL set for each of the plurality of ionospheric threat scenarios are computed. A maximum PL set is selected based on the main PL set and the supplemental PL sets to form a final PL set that protects the main solution against nominal navigation threats and severe ionospheric threats.

A low-earth orbit (LEO) satellite includes a non-atomic clock configured to generate a clock signal, a navigation signal receiving and processing module, and a navigation signal generation and transmission module. The navigation signal receiving and processing module is configured to receive the clock signal from the non-atomic clock, receive first signaling including first timing data generated based on a high precision clock, and generate clock state data based on the clock signal and the first timing data. The navigation signal generation and transmission module is configured to receive the clock signal from the non-atomic clock, generate a navigation message that indicates the clock state data, generate a broadcast carrier signal by utilizing the clock signal, generate a navigation signal based on modulating the navigation message upon the broadcast carrier signal, and broadcast the navigation signal for receipt by at least one client device.

The present application provides a method for navigation and positioning of a receiver, including: receiving basic broadcast messages and correction parameters of a plurality of satellites, and establishing a pseudorange observation equation and a carrier-phase observation equation corresponding to each of satellites respectively; correcting the pseudorange observation equation and the carrier-phase observation equation using the received correction parameters to obtain the corrected pseudorange observation equation and the corrected carrier-phase observation equation; constructing a first observation according to the corrected pseudorange observation equation and the corrected carrier-phase observation equation; constructing a second observation according to the corrected pseudorange observation equation and the corrected carrier-phase observation equation; and jointly solving the obtained first observations and second observations of the plurality of satellites to obtain anoperation result of user positioning.

Methods of checking the integrity of the estimation of the position of a mobile carrier are provided, the position being established by a satellite-based positioning measurement system, the estimation being obtained by the so-called “real time kinematic” procedures. The method verifies that the carrier phase measurement is consistent with the code pseudo-distance measurement. The method comprises a step of calculating the velocity of the carrier, at each observation instant, a step of verifying that at each of the observation instants, the short-term evolution of the carrier phase of the signals received on each of the satellite sight axes is consistent with the calculated velocity and a step of verifying that at each of the observation instants, the filtered position obtained on the basis of the long-term filtered measurements of pseudo-distance through the carrier phase is dependable.

A GBAS integrity risk allocation system based on key satellites is used to perform a GBAS integrity risk allocation method, including: reading data from an ephemeris at a certain time, and determining numbers of key satellites, key satellite pairs and key satellite groups at a certain time; under H2 hypothesis, allocating the integrity risks by using the fault probability of satellites in key satellite pairs or key satellite groups, where the integrity risks allocated by using the fault probability of satellites in key satellite pairs or key satellite groups include integrity risks caused by dual-receiver fault and integrity risks caused by ranging source fault; under H0 and H1 hypotheses, allocating the integrity risks by using the fault probability of non-key satellites; making an integrity allocation table according to the integrity risk allocation under the H0, H1 and H2 hypotheses.

Techniques described herein provide ways in which a quantity of signaling may be limited between a user equipment (UE) and a location server (LS) for a location session and a positioning protocol such as LPP or LPP/LPPe. The positioning protocol may be enhanced to allow the LS to indicate to the UE a limit on the overall size of assistance data (AD) that the UE can request and/or a limit on the overall amount of location information (LI) that the UE can return. A recipient UE can then prioritize any request for AD such that more important AD should fit within the size limit. The recipient UE can also prioritize returned location measurements such that more useful measurements are included in a message to the LS that is compliant to the limit indicated by the LS.

A method for optimally fitting GIVE ionospheric correction error bounds and/or a method for computing variances of residuals of IGP points of an ionospheric grid for correcting an SBAS system each comprise a step of inverse interpolation implemented on a set of observation pierce points IPPi. In the method for optimally fitting the GIVEs, the step of inverse interpolation scatters for each observation pierce point IPPi concerned a variance increment .sub.UIVE.sub.i.sup.2 over the IGP points of the mesh cell of the IPPi by using a least squares scheme. In the computation of the variances of residuals, the step of inverse interpolation scatters for each observation pierce point IPPi concerned a residual Res.sup.2 over the IGP points of the mesh cell of the IPPi by using a least squares scheme.