  The UK Schmidt Telescope (UKST) of the Anglo-Australian Observatory completed
a narrow-band H-alpha plus [NII] 6548, 6584A survey of the Southern Galactic
Plane and Magellanic Clouds in late 2003. The survey, which was the last UKST
wide-field photographic survey, and the only one undertaken in a narrow band,
is now an on-line digital data product of the Wide-Field Astronomy Unit of the
Royal Observatory Edinburgh (ROE). The survey utilised a high specification,
monolithic H-alpha interference band-pass filter of exceptional quality. In
conjunction with the fine grained Tech-Pan film as a detector it has produced a
survey with a powerful combination of area coverage (4000 square degrees),
resolution (~1 arcsecond) and sensitivity (<=5 Rayleighs), reaching a depth for
continuum point sources of R~20.5. The main survey consists of 233 individual
fields on a grid of centres separated by 4 degrees at declinations below +2
degrees and covers a swathe approximately 20 degrees wide about the Southern
Galactic Plane. The original survey films were scanned by the SuperCOSMOS
measuring machine at the Royal Observatory, Edinburgh to provide the on-line
digital atlas called the SuperCOSMOS H-alpha Survey (SHS). We present the
background to the survey, the key survey characteristics, details and examples
of the data product, calibration process, comparison with other surveys and a
brief description of its potential for scientific exploitation.
