Methods and systems disclosed herein may include receiving signals from a transmitter in a receiver; determine a bias of the transmitter and receiver; generating expected observations, based on the bias, corresponding to the received signals; and calculate a building height based on a power level of the received signals and a power level of the expected observations.

A central location system provides an end-to-end high-accuracy positioning solution that provides navigation, geo-tagging, and general positioning data to receivers. The central location system does this by providing a cloud correction service and a robust positioning engine. For example, the central location system may provide single-frequency receivers with corrections for atmospheric delays and multipath throughout different geographic regions. The central location system computes corrections by leveraging location data from dual-frequency receivers. The central location system may also increase ionospheric delay coverage of portions of a geographic region. With increased ionospheric delay coverage, receivers can compute better location estimates. The central location system may also compute refined location estimates of single-frequency receivers and/or dual-frequency receivers for receivers with limited access to signals transmitted from satellites. The central location system may do this by estimating a receiver's location with respect to the location estimates of other receivers.

A positioning assistance apparatus 1 that improves the positioning accuracy includes an estimation unit 2 that estimates a delay amount (ionosphere delay amount or a troposphere delay amount) using a model generated through machine learning (an ionosphere delay model or a troposphere delay model) and a degree-of-precision calculation unit 3 that calculates a degree of precision with respect to a delay amount (an ionosphere delay amount or a troposphere delay amount) calculated through positioning computation, using the estimated delay amount.

A method for converting state space representation (SSR) information to observation space representation (OSR) information includes: obtaining the SSR information, obtaining the OSR information, obtaining information of a virtual observation distance, and obtaining delay information of a troposphere and delay information of an ionosphere. A device for converting SSR information to OSR information includes: a satellite antenna, a global navigation satellite system (GNSS) board, a radio antenna, a mobile network module and antenna, a Bluetooth module and antenna, a Wi-Fi module and antenna, a status indicator light, a plurality of output interfaces, and a power supply unit. A conversion algorithm is realized for converting SSR information to OSR information, and the converted OSR information follows the international standard protocols and can be received by most GNSS receivers. A conversion device is developed based on the aforementioned method.

Systems and methods for sharing convergence data between GNSS receivers are disclosed. Convergence data received at a GNSS receiver via a communication connection may be utilized to determine a position of the GNSS receiver.

The present disclosure provides an integrity monitoring method of ionosphere gradient based on kinematical to kinematical platform, comprising step 1, constructing geometry-free and ionospheric amplification type detection statistics, based on original triple-frequency carrier phase observations, step 2, adjusting a detection threshold based on a required monitoring false alarm rate, and determining whether the detection statistics are less than the adjusted detection threshold, step 3, comparing a calculated miss-detection rate and a required miss-detection rate, and determining whether the calculated miss-detection rate are less than the required miss-detection rate, and step 4, if the detection statistics are less than the adjusted detection threshold and the calculated miss-detection rate are less than the required miss-detection rate, considering the ionosphere gradient is normal.

An augmentation information adjustment unit (102) reduces an amount of information in augmentation information by combining: update cycle adjustment processing (1021) to set an update cycle of the augmentation information to be an integer multiple of a predetermined update cycle; geographic interval error value adjustment processing (1022) 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 (1023) to reduce a bit count of the error value for each error value. An augmentation information output unit (103) outputs, to an output destination, augmentation information after being reduced in the amount of information by the augmentation information adjustment unit (102).

Described are methods, systems, and devices for correcting ionospheric error. In some aspects, a mobile device equipped with a Global Navigation Satellite System (GNSS) receiver is configured to determine a positioning measurement of a GNSS signal. The mobile device is further configured to receive augmentation data from an augmentation system. When augmentation data for a current measurement period is unavailable, the mobile device can obtain augmentation data associated with Total Electron Content (TEC) values (e.g., vertical TEC values) during one or more prior measurement periods. Based on the augmentation data associated with TEC values during one or more prior measurement periods and a pierce point of the received GNSS signal, an ionospheric error in the positioning measurement of the GNSS signal can be determined and corrected.

Methods and apparatus for processing of GNSS signals are presented. These include GNSS processing with obtaining GNSS data derived from signals received at a rover antenna, obtaining correction data, maintaining a time sequence of at least one rover position and at least one rover position difference with associated time tags, using the time sequence to determine at least one derived rover position by, starting from a position determined using corrections synchronous with rover data as an anchor position at a time tag, deriving a new anchor position for the time tag of the anchor position and at least one other estimated rover position at the time tag of the anchor position, and/or reporting the new anchor position and/or a new derived rover position.

A satellite orbiting in one of a plurality of orbital planes of a satellite constellation system at an altitude range corresponding to low earth orbit includes at least one processor configured to generate satellite state data, and to generate a navigation signal based on the satellite state data. The satellite includes at least one transmitter configured to transmit the navigation signal for receipt by at least one client device on earth. Each of the plurality of orbital planes includes a corresponding one of a plurality of satellite subsets of a plurality of satellites of the satellite constellation system. Each of the plurality of orbital planes is within the altitude range, and the plurality of orbital planes includes a set of inclined orbital planes at a non-polar inclination.