Phased array antenna pointing direction estimation and control

A method of maintaining a phased array antenna of an earth bound first device pointed at a second device, the method comprising:

• (a) reading a first position of the antenna array of the earth bound first device;
• (b) looking up a second position of the second device;
• (c) determining an angle of arrival of a signal coming from the second device to the phased array antenna based on the position of the second device and the position of the antenna array of the earth bound first device expressed within a local earth coordinate system, the local earth coordinate system having an origin at a positon of the first device on earth;
• (d) determining a direction of a local vector quantity at the positon of the antenna array pointing in a reference direction chosen from the group consisting of a direction of gravity, a direction to a celestial object, and magnetism of the earth;
• and
• (e) determining the pointing direction of the phased array antenna in the local earth coordinate system, the local earth coordinate system having an origin at a positon of the first device on earth based on the angle of arrival of the signal determined in said step (c) and the direction of a vector quantity determined in said step (d).

An apparatus, comprising:

• an antenna array for reading a first position of an earth bound first device;
• an orientation tracking device for looking up a second position of a second device;
• and
• a controller operatively coupled to the antenna array and the orientation tracking device to maintain the phased array antenna pointed at the second device by at least (A) determining an angle of arrival of a signal coming from the second device to the phased array antenna based on the position of the second device and the position of the antenna array of the earth bound first device expressed within a local earth coordinate system, the local earth coordinate system having an origin at a positon of the first device on earth, (B) determining a direction of a local vector quantity at the positon of the antenna array pointing in a reference direction chosen from the group consisting of a direction of gravity, a direction to a celestial object, and magnetism of the earth, and (C) determining the pointing direction of the phased array antenna in the local earth coordinate system, the local earth coordinate system having an origin at a positon of the first device on earth based on the angle of arrival of the signal determined in said step (A) and the direction of a vector quantity determined in said step (B).