We are conducting a robotic wide-angle imaging survey of the southern sky at 656.3 nm wavelength, the Hα emission line of hydrogen. Each image of the survey covers an area of the sky 13° square at an angular resolution of approximately one arcminute, and reaches a sensitivity level of 0.5 Rayleigh (3 × 10−18erg cm−2s−1arcsec−2), corresponding to an emission measure of 1 cm−6pc, and to a brightness temperature for microwave free-free emission of 3 µK at 30 GHz.