A high performance attitude determination system, including a global navigation satellite system (GNSS) receiver, the receiver including a first radio-frequency front-end (RF1) connected to a main antenna; a second radio-frequency front-end (RF2) connected to an auxiliary antenna; and a digital section connected to both RF1 and RF2. The digital section (i) generates a first set of GNSS raw measurements based on signals received from RF1; (ii) generates a second set of GNSS raw measurements based on signals received from RF2; (iii) computes a spatial attitude of a baseline between main and auxiliary antennas, using the first and the second sets of GNSS raw measurements, and based on carrier phase integer ambiguity resolution; (iv) continues updating the spatial attitude using the first and the second sets of GNSS raw measurements without carrier phase integer ambiguity resolution, and using fractional carrier phases. Optionally, RF1 and RF2 use a common clock.

A high performance attitude determination system, including a global navigation satellite system (GNSS) receiver, the receiver including a first radio-frequency front-end (RF1) connected to a main antenna; a second radio-frequency front-end (RF2) connected to an auxiliary antenna; and a digital section connected to both RF1 and RF2. The digital section (i) generates a first set of GNSS raw measurements based on signals received from RF1; (ii) generates a second set of GNSS raw measurements based on signals received from RF2; (iii) computes a spatial attitude of a baseline between main and auxiliary antennas, using the first and the second sets of GNSS raw measurements, and based on carrier phase integer ambiguity resolution; (iv) continues updating the spatial attitude using the first and the second sets of GNSS raw measurements without carrier phase integer ambiguity resolution, and using fractional carrier phases. Optionally, RF1 and RF2 use a common clock.

A high performance attitude determination system, including a global navigation satellite system (GNSS) receiver, the receiver including a first radio-frequency front-end (RF1) connected to a main antenna; a second radio-frequency front-end (RF2) connected to an auxiliary antenna; and a digital section connected to both RF1 and RF2. The digital section (i) generates a first set of GNSS raw measurements based on signals received from RF1; (ii) generates a second set of GNSS raw measurements based on signals received from RF2; (iii) computes a spatial attitude of a baseline between main and auxiliary antennas, using the first and the second sets of GNSS raw measurements, and based on carrier phase integer ambiguity resolution; (iv) continues updating the spatial attitude using the first and the second sets of GNSS raw measurements without carrier phase integer ambiguity resolution, and using fractional carrier phases. Optionally, RF1 and RF2 use a common clock.

Disclosed is a system and method for detecting false Global Navigation Satellite System (GNSS) satellite signals. False GNSS satellite signals can be used malevolently to take control of a body such as a vehicle or ship that is using GNSS satellite signals for navigation. In some embodiments a GNSS attitude system is used to detect the false GNSS satellite signals. The GNSS attitude system measures the code or carrier phase of the GNSS satellite signals at two or more antennas to detect the false GNSS satellite signals. In some embodiments the attitude system computes first measured and second estimated carrier phase differences in order to detect the false GNSS satellite signals. The attitude system may compute the attitude of a baseline vector between the two antennas. Once false GNSS satellite signals are detected, the method can include preventing the attitude determining system from outputting position or location data.

Disclosed is a system and method for detecting false Global Navigation Satellite System (GNSS) satellite signals. False GNSS satellite signals can be used malevolently to take control of a body such as a vehicle or ship that is using GNSS satellite signals for navigation. In some embodiments a GNSS attitude system is used to detect the false GNSS satellite signals. The GNSS attitude system measures the code or carrier phase of the GNSS satellite signals at two or more antennas to detect the false GNSS satellite signals. In some embodiments the attitude system computes first measured and second estimated carrier phase differences in order to detect the false GNSS satellite signals. The attitude system may compute the attitude of a baseline vector between the two antennas. Once false GNSS satellite signals are detected, the method can include preventing the attitude determining system from outputting position or location data.

An apparatus includes a controller coupled to at least two antennas and one or more sensors. An initial azimuth value for the apparatus is determined based on output of the one or more sensors. Respective phase differences between satellite signals received from respective satellites at the at least two antennas are detected, and respective phase difference values for the respective satellites are calculated based on the initial azimuth value, a distance between the at least two antennas in the apparatus, and positions of the respective satellites. An actual azimuth angle of the apparatus is identified based on the initial azimuth value from the output of the one or more sensors and variations between the respective detected phase differences and the respective calculated phase difference values for the respective satellites.

An apparatus includes a controller coupled to at least two antennas and one or more sensors. An initial azimuth value for the apparatus is determined based on output of the one or more sensors. Respective phase differences between satellite signals received from respective satellites at the at least two antennas are detected, and respective phase difference values for the respective satellites are calculated based on the initial azimuth value, a distance between the at least two antennas in the apparatus, and positions of the respective satellites. An actual azimuth angle of the apparatus is identified based on the initial azimuth value from the output of the one or more sensors and variations between the respective detected phase differences and the respective calculated phase difference values for the respective satellites.

Systems and methods for use in navigating aircraft are provided. The systems can use Geometry Redundant Almost Fixed Solutions (GRAFS) or Geometry Extra Redundant Almost Fixed Solutions (GERAFS) to compute high confidence error bounds for a heading angle estimate or pitch angle derived using signals received on at least two antennas.

The determination of an integer value bias may be performed at high speed. A positioning device, may include a FLOAT solution calculating part and an integer value bias determining part. The FLOAT solution calculating part may use carrier phase differences between carrier phases obtained by a plurality of antennas of a first station and a carrier phase obtained by one or more antennas of a second station provided separately from the first station to calculate a FLOAT solution of a particular position that is a relative position with respect to the second station, without using posture information on the first station. The integer value bias determining part may determine an integer value bias of the carrier phase difference, using the FLOAT solution of the particular position and the posture information on the first station.

A positioning method and device used for solving the problems of the existing method for determining an integer ambiguity being relatively difficult and relatively time-consuming. During positioning, the method includes a receiving device determining a virtual phase measured value according to at least two received C-PRS signals (600); determining a TOA measured value according to a received PRS signal (601); determining a virtual integer ambiguity according to the TOA measured value and the virtual phase measured value (602); and finally, determining the location of the receiving device according to the virtual integer ambiguity (603). An integer ambiguity search space is reduced, and the integer ambiguity is determined faster, thus improving the efficiency of determining the location of the receiving device.