Automation of the Spectral-Line Imaging Camera for the Virginia Tech Spectral-Line Survey

The Virginia Tech Spectral-Line Survey (VTSS) is a high sensitivity, high resolution survey of Hydrogen-$\alpha$ and Sulfur-II emission in the full northern hemisphere. The instrument used for the survey is the Spectral Line Imaging Camera (SLIC). SLIC uses a fast(f/1.2) lens attached to a cryogenically cooled, TK 512x512 CCD with 27 micron pixels. The focal length of the lens is 58mm which gives a pixel size of 1.6 arcminutes. The diameter of each field is 10degrees. A filter wheel ahead of the lens allows for imaging at different wavelengths. Automating the imaging system is desirable and advantageous due to the large scope of the survey. A variety of devices have been developed in order to implement automation of the SLIC observatory. They include an automated focusing mechanism, filter wheel, liquid nitrogen auto fill system, motorized roll-off roof, cloud monitor, and an equatorial mount. A PERL script, called SLICAR (Spectral Line Imaging Camera Automation Routine), was written to control and communicate with the various hardware and software components. The program also implements a user prepared Observing File, and makes decisions based on observing conditions.