Douglas Finkbeiner at Princeton University
For compositing the Virginia Tech Spectral line Survey (VTSS)
in the northern hemisphere, the Southern H-Alpha Sky Survey Atlas (SHASSA) in the southern hemisphere,
Hydrogen alpha (HA) filters, and the Wisconsin H-Alpha Mapper (WHAM) survey (H-A data set)
http://www.astro.princeton.edu/~dfink/halpha/