A Preliminary Plan of a Scientific CCD Attached to the LLMC

According to the requirement of the LLMC that the instrument can still determine absolutely the position of a celestial object after a scientific CCD is attached to the LLMC, a preliminary plan is put forward in this paper. The plan includes the follow ing three parts. Firstly, how does the CCD follows the track of the image of a star when it is observed in the meridian? Secondly, how does the telescope follow the track of the image of a star in the angle of elevation? Lastly, how does the variation of the optical axis of the telescope is determined accurately? Besides, the sky area that can be observed in one CCD exposure at different declination parallels is estimated.