An information sending method includes: obtaining first information for positioning a terminal device, the first information comprising differential positioning information, or the first information comprising at least one of environmental information or a satellite positioning signal, and differential positioning information; and when the first information satisfies a preset condition, sending the differential positioning information to the terminal device. The method can effectively reduce the sending of unnecessary differential positioning information, thereby avoiding unnecessary energy consumption waste of a roadside device and the terminal device, saving the time of the terminal device to calculate position information, and improving the high-precision positioning efficiency of the system.

An information sending method includes: obtaining first information for positioning a terminal device, the first information comprising differential positioning information, or the first information comprising at least one of environmental information or a satellite positioning signal, and differential positioning information; and when the first information satisfies a preset condition, sending the differential positioning information to the terminal device. The method can effectively reduce the sending of unnecessary differential positioning information, thereby avoiding unnecessary energy consumption waste of a roadside device and the terminal device, saving the time of the terminal device to calculate position information, and improving the high-precision positioning efficiency of the system.

The disclosure relates to a method for checking the integrity of GNSS correction data, comprising at least the following steps: a) receiving GNSS correction data, which are provided without associated integrity information, b) receiving reference data which allow for a conclusion to be drawn in respect of the integrity of the GNSS correction data received in step a), and c) checking the integrity of the GNSS correction data received in step a) by means of the reference data received in step b).

The disclosure relates to a method for checking the integrity of GNSS correction data, comprising at least the following steps: a) receiving GNSS correction data, which are provided without associated integrity information, b) receiving reference data which allow for a conclusion to be drawn in respect of the integrity of the GNSS correction data received in step a), and c) checking the integrity of the GNSS correction data received in step a) by means of the reference data received in step b).

In one implementation, first and second messages are received that include encoded position information for a transmitter. It is determined that both were received within some time of a previous message and that the second message was received within some time of the first message. A first location of the transmitter is determined based on the encoded position in the first message and the previously determined location. A second location of the transmitter is determined based on the encoded position in the second message and the previously determined location. It also is determined that the first and second locations are within a threshold distance. An updated second location of the transmitter is determined based on the encoded position information in the second message and the first location. A determination is made that the second location and the updated second location are within a threshold distance.

In one implementation, first and second messages are received that include encoded position information for a transmitter. It is determined that both were received within some time of a previous message and that the second message was received within some time of the first message. A first location of the transmitter is determined based on the encoded position in the first message and the previously determined location. A second location of the transmitter is determined based on the encoded position in the second message and the previously determined location. It also is determined that the first and second locations are within a threshold distance. An updated second location of the transmitter is determined based on the encoded position information in the second message and the first location. A determination is made that the second location and the updated second location are within a threshold distance.

A GPS filter-setting method comprises collecting, by a GPS filter-setting server, terminal information of a user terminal and GPS signal receiving environment information, setting, by the GPS filter-setting server, a filtering parameter used to filter an invalid GPS signal in the user terminal based on the collected terminal information of the user terminal and the GPS signal receiving environment information and transmitting, by the GPS filter-setting server, the set filtering parameter to the user terminal.

A GPS filter-setting method comprises collecting, by a GPS filter-setting server, terminal information of a user terminal and GPS signal receiving environment information, setting, by the GPS filter-setting server, a filtering parameter used to filter an invalid GPS signal in the user terminal based on the collected terminal information of the user terminal and the GPS signal receiving environment information and transmitting, by the GPS filter-setting server, the set filtering parameter to the user terminal.

The present invention discloses a high-precision point positioning method and device based on a smartphone. The method of the present invention, which belongs to the technical field of satellite positioning, improves the conventional PPP uncombined positioning model, and only uses original GNSS observation values received by a smartphone to carry out high-precision positioning without GNSS reference stations. The positioning method of the present invention comprises following steps: acquiring original observation values of the smartphone, such as GNSS pseudoranges and carrier phases; after preprocessing the data to decrease part of error influences, generating an uncombined model from the original observation values according to an improved precise point positioning method based on an estimation of double clock biases; determining each satellite observation value weight according to a satellite elevation angle; and carrying out filtering positioning by an improved Kalman filtering method to give a high-precision point positioning result.

A method and system for estimation of the current location of a remote radio beacon, at a mobile device, based on two historical positions thereof provided via at least two satellite relays and one base station, particularly usable for Search and Rescue. A beacon is configured to periodically transmit short RF signals, relayed by a first satellite payload to a base station, at which the position of the beacon is resolved; then, the base station transmits a message, relayed by a second satellite payload and detectable by a mobile device, encoding two previous positions of the beacon, stamped with time tags. Finally, the mobile device decodes the information about said two previous positions of the beacon, and accordingly estimates the current position of the beacon, accounting for possible different time references.