HEADING DETERMINATION SYSTEM USING ROTATION WITH GNSS ANTENNAS
A heading determination system using signals from a global navigation satellite system (GNSS) includes a rotator mechanism for rotating an array of GNSS antennas. The antenna array rotational orientation relative to a structure, such as a vehicle, can be determined by an angular sensor. By rotating the antennas, multipath error can be nullified. Greater GNSS guidance accuracy and heading determination can be achieved by reducing or eliminating multipath error. The system is also adapted for providing output corresponding to the tilt and roll angles for a mobile structure on which it is mounted using two antennas, with the rotation angle being at least 90°.
1 . A global navigation satellite system (GNSS) heading and guidance system for a mobile structure, which system comprises:
a primary antenna;
a second antenna adapted for mounting in spaced relation from said primary antenna;
a receiver unit including a GNSS receiver connected to said antennas, a clock and a processor;
a rotating platform adapted for rotatably mounting on said mobile structure;
at least one of said antennas being mounted on said rotating platform in spaced relation from the other said antenna;
a motor attached to and adapted for rotating said platform relative to said mobile structure; and
an angle sensor connected to said platform and adapted for providing an output to said processor, said angle sensor output corresponding to an angle of said platform relative to said mobile structure.
2 . The GNSS heading and guidance system of claim 1 , wherein:
said antenna separation is greater than the frequency wavelength of signals being received by said first and second antennas.
3 . The GNSS heading and guidance system of claim 2 , wherein:
said GNSS receiver is adapted for receiving GNSS signals from one or more of the list comprising: GPS L1, L2, or L5; GLONASS; Beidou; and Galileo GNSS systems.
4 . The GNSS heading and guidance system of claim 1 , which includes:
an inertial measurement unit (IMU) attached to said platform between said first and second antennas and connected to said processor.
5 . The GNSS heading and guidance system of claim 1 , which includes:
a gyroscope attached to said platform between said first and second antennas and connected to said processor.