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.

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 system and method for detecting spoofing of a Global Navigation Satellite System (GNSS) system using a plurality of antennas. Signals received by at least two of the plurality of antennas are authentication by use of one or more of a carrier phase authentication procedure, a signal power authentication procedure, and/or a channel distortion authentication procedure.

A system and method for detecting spoofing of a Global Navigation Satellite System (GNSS) system using a plurality of antennas. Signals received by at least two of the plurality of antennas are authentication by use of one or more of a carrier phase authentication procedure, a signal power authentication procedure, and/or a channel distortion authentication procedure.

An apparatus for vector tracking a plurality of satellite signals received by a Global Navigation Satellite System (GNSS) receiver from a plurality of satellites and a method for use thereof. The apparatus comprises: a hypothesis determiner configured to determine a most likely velocity hypothesis from a plurality of velocity hypotheses based on a plurality of correlation values, and to transfer data related to the most likely velocity hypothesis to a navigation engine of the GNSS receiver for tracking the satellite signals, wherein the plurality of velocity hypotheses have been generated based on a navigation engine output indicative of a current and/or a previous extended velocity solution for the GNSS receiver; and wherein the plurality of correlation values have been determined by a plurality of correlators and represent correlations between a plurality of first signals each comprising an expected Doppler shift derived from one of the plurality of velocity hypotheses, and a plurality of second signals each comprising a true Doppler shift derived from one of the plurality of satellite signals.

An apparatus for vector tracking a plurality of satellite signals received by a Global Navigation Satellite System (GNSS) receiver from a plurality of satellites and a method for use thereof. The apparatus comprises: a hypothesis determiner configured to determine a most likely velocity hypothesis from a plurality of velocity hypotheses based on a plurality of correlation values, and to transfer data related to the most likely velocity hypothesis to a navigation engine of the GNSS receiver for tracking the satellite signals, wherein the plurality of velocity hypotheses have been generated based on a navigation engine output indicative of a current and/or a previous extended velocity solution for the GNSS receiver; and wherein the plurality of correlation values have been determined by a plurality of correlators and represent correlations between a plurality of first signals each comprising an expected Doppler shift derived from one of the plurality of velocity hypotheses, and a plurality of second signals each comprising a true Doppler shift derived from one of the plurality of satellite signals.

A satellite positioning receiver includes a local oscillator, a front-end circuit with having an analog mixer, a number of signal processing channel circuits, and a processing circuit. The satellite positioning receiver performs a method that includes (i) acquiring a first satellite using a first frequency search space that spans both uncertainties due to the first satellite's orbit and uncertainties due to the clock bias or a time rate of change of the bias; and (ii) using the bias or the time derivative of the bias determined during the acquisition of the first satellite, acquiring a second satellite using a second frequency search space that spans substantially only uncertainties due to the second satellite's orbit.

A satellite positioning receiver includes a local oscillator, a front-end circuit with having an analog mixer, a number of signal processing channel circuits, and a processing circuit. The satellite positioning receiver performs a method that includes (i) acquiring a first satellite using a first frequency search space that spans both uncertainties due to the first satellite's orbit and uncertainties due to the clock bias or a time rate of change of the bias; and (ii) using the bias or the time derivative of the bias determined during the acquisition of the first satellite, acquiring a second satellite using a second frequency search space that spans substantially only uncertainties due to the second satellite's orbit.

A position detection method to be executed by a computer, the position detection method includes transmitting, by a sensor terminal, a signal obtained by performing capture processing on a satellite signal from a satellite of a search target according to an order of the satellites of the search targets; calculating, by a calculation device, a position of the sensor terminal based on a signal transmitted by the sensor terminal; and determining a satellite having a highest discovery probability based on a specific estimation method for second and subsequent search targets, using an index which is reflected larger as the discovery probability of other satellites is higher or lower, in a case where the first satellite is captured when a first search target is determined.

Techniques are provided for GNSS carrier phase multipath mitigation using a blanked correlator in conjunction with a full correlator. A tracking loop may track a carrier of the GNSS signal utilizing the full correlator. A chip-edge accumulation (CEA) unit of the tracking loop may accumulate chip edges of a ranging code to generate CEA output. A blanked correlator may receive the CEA output to generate blanked correlator values. A running-sum filter may utilize the blanked correlator values to generate a running-sum value. A phase estimate may utilize the running-sum value to generate phase estimator output. In an exemplary embodiment, the blanked correlator operates as a monitoring correlator and the phases estimator output is the estimated carrier phase multipath error. In an exemplary embodiment, the blanked correlator provides input to the tracking loop and discriminator output is subtracted from the phase estimator output to generate the estimated carrier phase multipath error.