Patent ID: 8355635
Filing Date: 2013-01-15
Classification: H04B

Abstract:
1. A method for pointing control of a laser communication terminal onboard a spacecraft, comprising: measuring a LOS error of the laser communication terminal, wherein measuring the LOS error comprises receiving a laser beam from a remote laser communications terminal by an optical receiver, the optical receiver providing a LOS error measurement; estimating a LOS error of the laser communication terminal based on measurements from a spacecraft gyro and a gimbal gyro onboard the spacecraft; and measuring a FSM position of a fast steering mirror that controls pointing of the laser communication terminal for communications; blending a measurement from the spacecraft gyro and a measurement from the gimbal gyro associated with a gimbal for pointing the laser communication terminal, to provide a base jitter rate of the laser communication terminal; determining a LOS error estimate of the laser communication terminal from the measured LOS error, the measured FSM position and the blended gyro measurement from the spacecraft gyro and the gimbal gyro; and switching from a LOS error measurement feedback to a LOS error estimate feedback to control the FSM position for pointing of the laser communication terminal during a power fade condition.