Techniques for precise positioning using differential carrier phase (DCP)-based measurement updates are disclosed. The techniques can include obtaining a pseudorange observation for a positioning epoch and a carrier phase observation for the positioning epoch based on measurements of global navigation satellite system (GNSS) signals transmitted by one or more space vehicles (SVs) of a GNSS constellation, generating a differential carrier phase observation for the positioning epoch based on the carrier phase observation for the positioning epoch and a determination that real-time kinematic (RTK) correction data associated with the GNSS constellation is unavailable, and generating a position, velocity, and time (PVT) observation of the mobile device for the positioning epoch based on the differential carrier phase observation for the positioning epoch.

Systems, devices, and methods for a vertical take-off and landing (VTOL) aerial vehicle having a first GPS antenna and a second GPS antenna, where the second GPS antenna is disposed distal from the first GPS antenna; and an aerial vehicle flight controller, where the flight controller is configured to: utilize a GPS antenna signal via the GPS antenna switch from the first GPS antenna or the second GPS antenna; receive a pitch level of the aerial vehicle from the one or more aerial vehicle sensors in vertical flight or horizontal flight; determine if the received pitch level is at a set rotation from vertical or horizontal; and utilize the GPS signal not being utilized via the GPS antenna switch if the determined pitch level is at or above the set rotation.

There is provided a method of selecting a satellite for positioning in a global navigation satellite system, which includes: receiving satellite signals from satellites that a receiver can receive; calculating DOP where pseudorange weight is applied for each of satellite signal combinations including at least four or more of the satellite signals by the receiver; and selecting a satellite signal combination having the smaller DOP than a standard in the satellite signal combinations by the receiver.

In the field of satellite geolocation, a geopositioning method with a trust index is implemented by a geopositioning terminal. According to the method, the positioning of the terminal is estimated by geopositioning satellites and the trust index is provided by comparison with at least one pseudo-distance measurement recorded by at least one additional geopositioning satellite, which is different from those used to compute the position of the terminal.

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.

A method for position measurement of a portable electronic device is provided. The method includes receiving, from a first satellite, first satellite information and state information of the first satellite information, receiving other state information of the first satellite information from a server that receives the other state information of the first satellite information from a terrestrial observatory, and using the first satellite information for the position measurement of the portable electronic device when the state information of the first satellite information received from the first satellite is unhealthy and the other state information of the first satellite information received from the server is healthy, wherein healthy state information indicates that satellite information may be used for the position measurement of the portable electronic device and unhealthy state information indicates that the satellite information may not be used for the position measurement of the portable electronic device.

An aircraft receives pseudorange input from a plurality of satellites of an augmentation system. Each pseudorange input includes a precise position solution and error data. The aircraft receives a high frequency measurement from an inertial navigation system. The aircraft applies the precise position solution, error data, and high frequency measurement to a set of parallel Schmidt extended Kalman filters to produce a corrected position solution and integrity data. The aircraft applies the integrity data to a receiver autonomous integrity monitoring system to produce a protection level for the corrected position solution. The aircraft performs an aircraft operation using the corrected position solution and protection level.

An aircraft receives pseudorange input from a plurality of satellites of an augmentation system. Each pseudorange input includes a precise position solution and error data. The aircraft receives a high frequency measurement from an inertial navigation system. The aircraft applies the precise position solution, error data, and high frequency measurement to a set of parallel Schmidt extended Kalman filters to produce a corrected position solution and integrity data. The aircraft applies the integrity data to a receiver autonomous integrity monitoring system to produce a protection level for the corrected position solution. The aircraft performs an aircraft operation using the corrected position solution and protection level.

A method of determining a navigational position from satellite navigation signals includes receiving at a satellite navigation receiver a plurality of satellite navigation signals, where each respective satellite navigation signal was transmitted by a respective satellite each of which belongs to one of a plurality of satellite navigation system. Each respective satellite navigation signal transmitted by the respective satellite includes time data based on a time base of a respective satellite navigation system to which the respective satellite belongs. The time data in at least one respective satellite signal is converted from the time base of the respective satellite navigation system to which the respective satellite belongs to make each satellite navigation signal usable with each other satellite navigation signal to derive the position. In one implementation, the conversion involves a known relationship between time bases, as well as a measured hardware correction, and results in a common time base.

A positional measurement system includes: a mobile robot including a global navigation satellite system (GNSS) signal reception unit that receives GNSS signals and calculates a position of the mobile robot based on the GNSS signals, a GNSS signal precision evaluation unit that evaluates positional measurement precision by the received GNSS signals, and a position control unit that moves the mobile robot to a high-precision reception position, where GNSS signals yielding positional measurement precision higher than a first threshold precision can be received; a relative position detection unit that detects a relative position of a target as to the mobile robot situated at the high-precision reception position; and a target position calculation unit that calculates a position of the target based on the calculated position of the mobile robot based on the GNSS signals received at the high-precision reception position, and the relative position.