Simplified yaw steering method for satellite antenna beam control
First Claim
Patent Images
1. A method of steering a satellite antenna mounted to a satellite having a pitch axis, a roll axis, and a yaw axis, the satellite traveling in an orbit around a rotating object, the orbit having an inclination and an ascending node, the method comprising the steps of:
- determining the inclination of the orbit;
determining the time in the orbit from the ascending node;
determining the period of the orbit;
determining the period of the rotation of the object; and
steering the antenna about the yaw axis by an angle, φ
, wherein φ
is a function of the inclination of the orbit, the time in the orbit from the ascending node, the period of the orbit, and the period of the rotation of the object.
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Abstract
For an antenna on a satellite in an inclined orbit about the Earth, cross-track motion resulting from the rotation of the Earth can be reduced in antenna coordinates by yawing the antenna (preferably by yawing the entire satellite, for example, by using a reaction wheel system) by an appropriate angle, which varies throughout the orbit.
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Citations
13 Claims
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1. A method of steering a satellite antenna mounted to a satellite having a pitch axis, a roll axis, and a yaw axis, the satellite traveling in an orbit around a rotating object, the orbit having an inclination and an ascending node, the method comprising the steps of:
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determining the inclination of the orbit;
determining the time in the orbit from the ascending node;
determining the period of the orbit;
determining the period of the rotation of the object; and
steering the antenna about the yaw axis by an angle, φ
, wherein φ
is a function of the inclination of the orbit, the time in the orbit from the ascending node, the period of the orbit, and the period of the rotation of the object.- View Dependent Claims (2, 3, 4)
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5. A method for steering a satellite antenna mounted to a satellite having a pitch axis, a roll axis, and a yaw axis, the satellite traveling in an orbit around the Earth, the orbit having an inclination and an ascending node, the method comprising the steps of:
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determining the inclination of the orbit;
determining the time in the orbit from the ascending node;
determining the period of the orbit; and
steering the antenna about the yaw axis by an angle, φ
, wherein φ
is a function of the inclination of the orbit, the time in the orbit from the ascending node, the period of the orbit, and the period of the rotation of the Earth.- View Dependent Claims (6, 7, 8)
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9. A method for reducing pointing errors while steering a satellite antenna mounted to a satellite having a pitch axis, a roll axis, and a yaw axis, the satellite traveling in an orbit around a rotating object, the orbit having an inclination and an ascending node and the antenna pointed generally at a target area on the object, the method comprising the steps of:
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determining the inclination of the orbit;
determining the time in the orbit from the ascending node;
determining the period of the orbit;
determining the period of the rotation of the object; and
steering the antenna about the yaw axis by an angle, φ
, wherein φ
is a function of the inclination of the orbit, the time in the orbit from the ascending node, the period of the orbit, and the period of the rotation of the object.- View Dependent Claims (10)
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11. A satellite having a pitch axis, a roll axis, and a yaw axis, the satellite traveling in an orbit around a rotating object, the orbit having an inclination and an ascending node and the antenna pointed generally at a target area on the object, the satellite comprising:
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a satellite antenna mounted to the satellite; and
means for reducing pointing errors while steering the satellite antenna by steering the antenna about the yaw axis by an angle, φ
, wherein φ
is a function of the inclination of the orbit, the time in the orbit from the ascending node, the period of the orbit, and the period of the rotation of the object.- View Dependent Claims (12, 13)
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Specification