A satellite corrections generation system receives reference receiver measurement information from a plurality of reference receivers at established locations. In accordance with the received reference receiver measurement information, and established locations of the reference receivers, the system determines narrow-lane navigation solutions for the plurality of reference receivers. The system also determines clusters of single-difference (SD) narrow-lane floating ambiguities, each cluster comprising pairs of SD narrow-lane floating ambiguities for respective pairs of satellites. A satellite narrow-lane bias value for each satellite of a plurality of satellites is initially determined in accordance with fractional portions of the SD narrow-lane floating ambiguities in the clusters, and then periodically updated by a Kalman filter. A set of navigation satellite corrections for each satellite, including the satellite narrow-lane bias value for each satellite, is generated and transmitted to navigation receivers for use in determining locations of the navigation receivers.

A satellite corrections generation system receives reference receiver measurement information from a plurality of reference receivers at established locations. In accordance with the received reference receiver measurement information, and established locations of the reference receivers, the system determines narrow-lane navigation solutions for the plurality of reference receivers. The system also determines, in accordance with the narrow-lane navigation solutions, at a first update rate, an orbit correction for each satellite of a plurality of satellites; at a second update rate, a clock correction for each such satellite; and at a third update rate that is faster than the second update rate, an update to the clock correction for each such satellite. Further, the system generates navigation satellite corrections for each such satellite, including the orbit correction updated at the first update rate, and the clock correction that is updated at the third update rate.

A satellite corrections generation system receives reference receiver measurement information from a plurality of reference receivers at established locations. In accordance with the received reference receiver measurement information, and established locations of the reference receivers, the system determines wide-lane navigation solutions for the plurality of reference receivers. The system also determines clusters of single-difference (SD) wide-lane floating ambiguities. A satellite wide-lane bias value for each satellite of a plurality of satellites is initially determined in accordance with fractional portions of the SD wide-lane floating ambiguities in the clusters and over-range adjustment criteria. A set of navigation satellite corrections for each satellite, including the satellite wide-lane bias value for each satellite, is generated and transmitted to navigation receivers for use in determining locations of the navigation receivers.

A positioning method comprises acquiring positioning information of a 5G base station from a satellite, obtaining calibration information based on the positioning information, and broadcasting outwards the calibration information; acquiring initial positioning information of a user terminal from the satellite; accessing a nearest 5G base station in real time, monitoring and acquiring calibration information broadcasted by the nearest 5G base station; and calibrating the initial positioning information acquired in the initial positioning step according to the calibration information acquired in the monitoring step to obtain positioning result information. As described above, the positioning of centimeter level precision can be realized by utilizing the 5G base station, and there is no need to additionally establish a CORS base station and a data center, thereby the cost of precise positioning can be reduced.

A method for improving accuracy of a raw GPS positioning of an untargeted pedestrian device wherein the pedestrian device receives from a nearby vehicle device a message containing a calculated offset between a raw GPS location of the vehicle and a corrected location of the vehicle, the message being received as a direct consequence of the pedestrian device and the vehicle device coming into mutual communication range without a need for pairing between the two devices. The calculated offset is applied to the raw GPS positioning of the pedestrian device to obtain a more accurate location of the pedestrian device.

Apparatus and methods for geo-locating an object. In some examples, a device for determining a geolocation of an object can include a receiver, a signal generator, a detector, and a central processing unit. The receiver can be configured to receive a location signal from a navigation satellite system. The signal generator can be configured to emit an electromagnetic radiation signal of visible light onto an object to be geolocated. The detector can be configured to receive a reflection of the emitted electromagnetic radiation signal of visible light from the object. The central processing unit can be configured to provide geographic coordinates of the device and geographic coordinates of the object based on the reflection of the emitted electromagnetic radiation signal of visible light from the object.

The interval between grid points to which transmitting positioning augmentation information is transmitted from a quasi-zenith satellite is set according to a fluctuation of an index value of an ionospheric state for each of a plurality of areas divided on the ground.

Various vehicle technologies for improving positioning accuracy despite various factors that affect signals from navigation satellites. Such positioning accuracy is increased via determining an offset and communicating the offset in various ways or via sharing of raw positioning data between a plurality of devices, where at least one knows its location sufficiently accurately, for use in differential algorithms.

The present disclosure discloses a method and a system for preventing leakage of Beidou differential positioning data. The method includes the following steps: step 1, determining the number of positioning terminals; step 2, making identification cards, wherein one identification card corresponds to one positioning terminal, and writing data into each identification card; step 3, putting the identification cards into the card slots of the positioning terminals corresponding to the identification cards; step 4, verifying whether the read data is accurate; step 5, generating the Beidou differential positioning data by the positioning base station, a positioning satellite and the positioning terminals operating normally. The system includes a positioning base station, a positioning satellite, a service terminal, a card issuing device, a plurality of identification cards and a plurality of positioning terminals.

In one aspect of the present disclosure, an apparatus for locating a mobile railway asset is provided that includes a power source, GNSS circuitry configured to utilize electrical power from the power source to receive GNSS data, and a controller operatively coupled to the power source and the GNSS circuitry. The controller has a power saving mode wherein the controller inhibits the GNSS circuitry from receiving GNSS data and a standard accuracy mode wherein the controller permits the GNSS circuitry to receive GNSS data for a first time period. The controller has a higher accuracy mode wherein the controller permits the GNSS circuitry to receive GNSS data for a second time period longer than the first time period, and subsequently across multiple instances, in order to collect more GNSS data that can be qualified, filtered, sorted, and averaged to produce a more accurate result.