An apparatus for estimating a direction of a vehicle includes: a vehicle position calculator calculating a current position of the vehicle and a current time using a received satellite signal; a satellite candidate predictor predicting satellite candidates that are observable at the calculated current position of the vehicle using ALMANAC data in which information about positions and azimuths of satellites is included and using the calculated current position of the vehicle and current time; a road candidate searcher searching road candidates positioned around the vehicle based on the calculated current position of the vehicle; and a direction estimator estimating the direction of the vehicle using information about the predicted satellite candidates and the searched road candidates.

Perception data based multipath identification and correction is based on recognition that sensors such as radar, LIDAR, and cameras can generate perception data indicative of locations and properties of terrestrial objects in an environment surrounding a satellite navigation device (e.g., a GNSS receiver), which data may then be used in training, or updating, a model for determining or correcting distances to satellites to account for multipath. Multipath identification includes identifying multipaths to train the model, e.g., by using perception data to perform ray tracing. Multipath correction includes using the model to correct distance errors due to the multipaths or, equivalently, using the model to determine distances to satellites in a manner that accounts for the multipaths.

A method of selecting a satellite positioning system which is used in positioning by a positioning device capable of performing positioning based on a plurality of satellite positioning systems includes acquiring given support information which is referred to in selecting a satellite positioning system, and selecting a satellite positioning system which is used in positioning from the plurality of satellite positioning systems, on the basis of the support information.

A system to select a type of satellite from a plurality of types of satellites in a multi-constellation of satellites is provided. The system includes at least a first receiver configured to input signals from a first type of satellite and a second receiver configured to input signals from a second type of satellite and a processor. The processor: executes a multi-constellation-selection software module to associate a current position with a mapping feature and select at least one selected type of satellite from the plurality of types of satellites based on the associated mapping feature; executes a compute-position/velocity/time (PVT) software module to compute a current position/velocity/time based on at least one selected input signal input at a receiver associated with the at least one selected type of satellite; and feeds the computed current position/velocity/time to the multi-constellation-selection software module based on the execution of the compute-PVT software module.

An unmanned aircraft navigation system includes a master navigation device, a slave navigation device, and a controller. The master navigation device includes at least one measurement component. The slave navigation device includes at least one measurement component configured to provide a redundancy support for the at least one measurement component of the master navigation device. The controller is configured to effect a navigation using the at least one measurement component of the master navigation device and the at least one measurement component of the slave navigation device.

A system for receiving and processing satellite signals from satellites of global navigation systems, in particular for a vehicle, having a signal path includes a signal conditioning unit for conditioning received satellite signals, an analysis unit for analyzing the conditioned satellite signals, and a position determination unit for determining measured values utilizing the satellite signals provided by the analysis unit. The measured values include a position, a speed, and/or a satellite time. The system has two signal paths which are separate from one another and each process mutually independent satellite signals for a position.

A plurality of GNSS satellite signals feeds multiple signal processing engines, each operating in certain processing mode including carrier smoothed pseudorange positioning, precise point positioning (PPP), pseudorange differential (DGNSS), carrier phase differential (RTK). Each processing engine (or processing thread of the same engine) runs the same unified numerical algorithm and uses the same or different sets of parameters. All engines can use the same set of signals, or the set of signals can be split into non-intersecting subsets, or the set of signals can be split into the overlapping subsets. Each engine produces estimates of certain parameters, namely carrier phase ambiguities and ionospheric delays for each satellite. These estimates are then combined into a resulting estimate which in turn is used for calculation of the final position reported by the receiver.

A mobile terminal capable of selecting optimum satellites among a plurality of positioning satellites and a method of selecting positioning satellites are disclosed with reference to embodiments of the present invention. If DOP (dilution of precision) increases as the number of positioning satellites increases, satellites to be used for positioning are automatically selected from GNSS satellites based on satellite information and a user's menu setting. This can enhance the accuracy of positioning and can reduce battery consumption. In particular, satellites for positioning are spaced from each other by a prescribed distance to reduce DOP, thereby enhancing the accuracy of positioning. Further, multipath signals are reduced in order to enhance the accuracy of positioning.

Various methods and apparatus relating to synchronizing location information between two or more devices are described. In some embodiments, the devices are both configured to generate GNSS receiver data that is synchronized to achieve greater location accuracy. In some embodiments, the GNSS receiver data can be weighted when one set of GNSS receiver data is known to have a higher accuracy than another set of GNSS receiver data.

An apparatus for estimating a direction of a vehicle includes: a vehicle position calculator calculating a current position of the vehicle and a current time using a received satellite signal; a satellite candidate predictor predicting satellite candidates that are observable at the calculated current position of the vehicle using ALMANAC data in which information about positions and azimuths of satellites is included and using the calculated current position of the vehicle and current time; a road candidate searcher searching road candidates positioned around the vehicle based on the calculated current position of the vehicle; and a direction estimator estimating the direction of the vehicle using information about the predicted satellite candidates and the searched road candidates.