The CATalog Server, or CAT, is designed to help the user select a star in a certain region of the sky for sending to the TCS as a target. Given a Right Ascension and Declination from the user, it will display all the stars in a certain radius from the given point in a visual and a tabular format.
The above image is the default layout for CAT. It is separated into four components: The User's view, the Image view, the Table view, and the Science Target view. Each of the views can be minimized or maximized within the current window; they can also be deleted or separated from the perspective as well as be moved around at the user's discretion. The control for each view is located at the top of the view. And to move or separate, the user only needs to click and drag it to the desired location.