Title: SHASSA: The Southern H-Alpha Sky Survey Atlas

Abstract: SHASSA (http://amundsen.swarthmore.edu/SHASSA/) is the product
of a robotic wide-angle imaging survey of the southern sky at 656.3 nm
wavelength, the H-Alpha line of interstellar hydrogen. Each image of the
Atlas covers an area of the sky 13 degrees square at an angular
resolution of about one arcminute and reaches a sensitivity of 2
rayleighs (corresponding to an emission measure of 4 cm^-6 pc). The
Atlas is being used to study the structure of the warm ionized component
of the interstellar medium, and to determine the contribution of
free-free emission to the Galactic microwave foreground. I will discuss
the history and some technical aspects of the survey, and give some
examples of current and potential applications.