Grid algorithm is a preferable star field identification algorithm. But it need many stars in FOV (fieldofview). Thereby CCD star tracker must have large FOV or be sensitive to dim stars.
Optical systems with large FOV are usually complex in design and have large distortion due to such factors as eccentric, fieldofview, and focal length.
大视场光学系统由于非共轴、视场、焦距等因素的影响，光学设计比较复杂，光学系统的畸变比较大。
3
Objective To evaluate the relationship between fieldofview (FOV) and quality of ct images.