Imagery payload design for passive magnetically stabilized microsatellite

The charge-coupled device (CCD) control logic design and analysis of pointing knowledge of a low-cost microsatellite, the Taiwan Universities United Satellite (TUUSAT), which applies passive magnetic attitude control system is discussed. The CCD mission of TUUSAT requires transmitting at least one image covering Taiwan, Republic of China, per day. To meet the mission requirements, a shooting zone centered at Taiwan is determined according to the regression of orbit and the spin rate of the satellite. Two cameras are employed in the present design. A simple scheme of CCD control logic is provided to determine the proper timing of shooting images. The determination of optimal setup angle of cameras in the satellite with the minimal pointing errors is analyzed. The simulation result shows the CCD control logic design and the selection of setup angle of cameras satisfactorily met the CCD mission requirement. The flowchart of implementation of CCD control logic is also presented. It is found that the control system design for the specified CCD mission can also be applied to the other places located at the same geomagnetic latitude as that of Taiwan.