Mobile terminal antenna alignment using arbitrary orientation attitude

A method for aligning an antenna to an attitude determining device, the antenna and the attitude determining device mounted on a platform, the antenna having an antenna reference frame and the attitude determining device having an attitude determining device reference frame, the method comprising:

• a. taking a plurality of attitude measurements indexed according to an index i, each of the plurality of attitude measurements taken at an i-th orientation of a plurality of orientations, to determine:
• i. a first vector {right arrow over (d)}i from the antenna to a satellite, the first vector being determined based on a location of the platform in the i-th orientation as determined by a position measuring device and a location of the satellite;
• and
• ii. a second vector {right arrow over (d)}′i by performing an alias transformation on the first vector {right arrow over (d)}i from a fixed reference frame to the attitude determining device reference frame based on an attitude of the platform;
• iii. a third vector {right arrow over (d)}″i from the antenna to the satellite when the antenna is peaked to the satellite with the platform in the i-th orientation, the third vector being represented by coordinates defined with respect to the antenna reference frame, the third vector {right arrow over (d)}″i being determined based on information indicating an attitude of the antenna;
• b. accumulating a collection of the second vectors {right arrow over (d)}′i and a collection of the third vectors {right arrow over (d)}″i based on the plurality of attitude measurements;
• c. estimating a first rotation matrix {circumflex over (T)} based on the accumulated collection of second vectors {right arrow over (d)}′i and the accumulated collection of third vectors {right arrow over (d)}″i;
• d. determining a rotational offset between the antenna reference frame and the attitude determining device reference frame based on the first rotation matrix {circumflex over (T)};
• and
• e. pointing, upon receiving information indicating a second location of the platform, the antenna at the satellite based on the information indicating the second location and the rotational offset.

A non-transitory computer-readable medium encoding program instructions operable to cause one or more machines to perform operations comprising:

• a. taking a plurality of attitude measurements indexed according to an index i, each of the plurality of attitude measurements taken at an i-th orientation of a plurality of orientations, to determine:
• i. a first vector {right arrow over (d)}i from an antenna to a satellite, the first vector being determined based on a location of a platform in the i-th orientation as determined by a position measuring device and a location of the satellite;
• and
• ii. a second vector {right arrow over (d)}′i by performing an alias transformation on the first vector {right arrow over (d)}i from a fixed reference frame to a reference frame of the position measuring device based on an attitude of the platform;
• iii. a third vector {right arrow over (d)}″i from the antenna to the satellite when the antenna is peaked to the satellite with the platform in the i-th orientation, the third vector being represented by coordinates defined with respect to reference frame of the antenna, the third vector {right arrow over (d)}″i being determined based on information indicating an attitude of the antenna;
• b. accumulating a collection of the second vectors {right arrow over (d)}′i and a collection of the third vectors {right arrow over (d)}″i based on the plurality of attitude measurements;
• c. estimating a first rotation matrix {circumflex over (T)} based on the accumulated collection of second vectors {right arrow over (d)}′i and the accumulated collection of third vectors {right arrow over (d)}″i;
• d. determining a rotational offset between the reference frame of the antenna and the reference frame of the position measuring device based on the first rotation matrix {circumflex over (T)};
• and
• e. pointing, upon receiving information indicating a second location of the platform, the antenna at the satellite based on the determined rotational offset and the information indicating the second location.

An antenna control unit (ACU) for generating and providing control signals to control a position of a satellite antenna mounted on a mobile platform, the mobile platform comprising a position and attitude measuring device (PAMD) and at least one processor configured to:

• a. take a plurality of attitude measurements indexed according to an index i, each of the plurality of attitude measurements taken at an i-th orientation of a plurality of orientations and being determined by:
• i. determining a first vector {right arrow over (d)}′i from the satellite antenna to a satellite based on a location of the mobile platform in the i-th orientation and a location of the satellite, the first vector {right arrow over (d)}i being represented by coordinates defined with respect to a fixed reference frame;
• ii. determining a second vector {right arrow over (d)}′i by performing an alias transformation on the first vector {right arrow over (d)}i, the alias transformation transforming the coordinates of the first vector {right arrow over (d)} from the fixed reference frame to a reference frame of the PAMD based on an attitude of the mobile platform when in the i-th orientation;
• and
• iii. determining a third vector {right arrow over (d)}″i from the antenna to the satellite based on an attitude of the satellite antenna when peaked to the satellite with the mobile platform in the i-th orientation, the third vector {right arrow over (d)}″i being represented in coordinates defined with respect to a reference frame of the satellite antenna;
• b. accumulate a collection of the second vectors {right arrow over (d)}′i and accumulate a collection of the third vectors {right arrow over (d)}″i based on the plurality of attitude measurements;
• c. estimate a rotation matrix {circumflex over (T)} based on the accumulated collection of second vectors {right arrow over (d)}′i and the accumulated collection of third vectors {right arrow over (d)}″i;
• d. determine a roll, pitch, and yaw offset between the reference frame of the PAMD and the reference frame of the satellite antenna based on the rotation matrix {circumflex over (T)};
• and
• e. point, upon receiving information indicating a second location of the mobile platform, the satellite antenna at the satellite based on the information indicating the second location and the roll, pitch and yaw offsets.