The disclosure relates to a method for determining the visibility of a satellite for a GNSS-based position determination, including: detecting the environment in a position, in particular determining an unobstructed view of the sky, by means of an environment sensor system and/or a GNSS sensor system and/or a camera sensor system; and merging the detected environment, in particular the unobstructed view of the sky, with a theoretical visibility of a satellite in the position.

The present disclosure relates to a method for performing a parallel search for a first positioning fix in a Global Navigation Satellite System (GNSS) receiver. The method includes, in some instances, determining prepositioning information, wherein the prepositioning information includes a receiver information and a satellite information for each satellite in a plurality of satellites. The method further includes determining a code phase search range and a frequency search range, based on the prepositioning information, for each satellite in the plurality of satellites. The method further includes determining a starting point information for each satellite in the plurality of satellites, wherein each respective starting point information is representative of an offset from a center of a search range of the respective satellite. The method further includes performing the parallel search for all satellites in the plurality of satellites based on the respective code phase search range, the respective frequency search range and the respective starting point information.

The present disclosure relates to a method for performing a parallel search for a first positioning fix in a Global Navigation Satellite System (GNSS) receiver. The method includes, in some instances, determining prepositioning information, wherein the prepositioning information includes a receiver information and a satellite information for each satellite in a plurality of satellites. The method further includes determining a code phase search range and a frequency search range, based on the prepositioning information, for each satellite in the plurality of satellites. The method further includes determining a starting point information for each satellite in the plurality of satellites, wherein each respective starting point information is representative of an offset from a center of a search range of the respective satellite. The method further includes performing the parallel search for all satellites in the plurality of satellites based on the respective code phase search range, the respective frequency search range and the respective starting point information.

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.

An apparatus for surveying a position of a static point, consisting of a GNSS receiver and a mobile computing device, connected with GNSS receiver via communication interface. The mobile computing device accepts from GNSS receiver several estimations of position of a static point within a single session and computes combined result for the current session, which is the average of those estimations. After that, a reset command is send to a GNSS receiver, and another session is performed in order to get another combined result. The process continues until a required number of mutually consistent session results is collected, where ‘consistent’ means having the scatter of session results within a certain margin. Upon collecting the required number of consistent session results, they are combined to compute a single estimate of the position of a static point, which is considered as a result of survey.

An apparatus for surveying a position of a static point, consisting of a GNSS receiver and a mobile computing device, connected with GNSS receiver via communication interface. The mobile computing device accepts from GNSS receiver several estimations of position of a static point within a single session and computes combined result for the current session, which is the average of those estimations. After that, a reset command is send to a GNSS receiver, and another session is performed in order to get another combined result. The process continues until a required number of mutually consistent session results is collected, where ‘consistent’ means having the scatter of session results within a certain margin. Upon collecting the required number of consistent session results, they are combined to compute a single estimate of the position of a static point, which is considered as a result of survey.

A system and method for detecting multiple spoofed or faulty global navigation satellite signals are provided. The system comprises a single antenna configured to receive satellite signals from a plurality of global navigation satellites, the single antenna located on a vehicle; a receiver in the vehicle, the receiver coupled to the single antenna; and at least one processor in the vehicle, the processor in communication with the single antenna through the receiver. The processor is operative to determine a unit vector in a direction from the vehicle to a global navigation satellite in local coordinates, from the satellite signals; determine a plurality of signal blocks, wherein the signal blocks are a collection of subsets of the satellite signals and a covariance matrix for the satellite signals; and determine which satellite signals in the signal blocks are spoofed or faulty by comparing a geometry of the local coordinates with satellite coordinates.

Provided is a method and apparatus for selecting an airborne position reference node. A weight center coordinate of the repeaters is calculated by using position coordinates of repeaters, a plane having a vector connecting the weight center coordinate and a position coordinate of a user as a normal vector is determined, and the position coordinates of the repeaters are orthographically projected onto the plane. A certain number of repeaters located farthest from the weight center coordinate of the repeaters are selected to be airborne position reference nodes, on the basis of the orthographically projected coordinates of the repeaters and the weight center coordinate.

A multiple faulty global navigation satellite signal detecting system is provided. The system includes at least one pair of spaced antennas, at least one aiding source and processor. The at least one pair of spaced antennas are configured to receive satellite signals from a plurality of satellites. The at least one aiding source is used to generate aiding source position estimate signals. The processor is in communication with each antenna and the at least one aiding source. The processor is configured to determine signals blocks. The signal blocks being a collection of subsets of the determined difference signals and a covariance matrix for the difference signals. The processor further configured to generate a union of good signals from all the good blocks and a complementary set of bad signals.

A multiple faulty global navigation satellite signal detecting system is provided. The system includes at least one pair of spaced antennas, at least one aiding source and processor. The at least one pair of spaced antennas are configured to receive satellite signals from a plurality of satellites. The at least one aiding source is used to generate aiding source position estimate signals. The processor is in communication with each antenna and the at least one aiding source. The processor is configured to determine signals blocks. The signal blocks being a collection of subsets of the determined difference signals and a covariance matrix for the difference signals. The processor further configured to generate a union of good signals from all the good blocks and a complementary set of bad signals.