The PHAT survey is a multicycle HST programme. The survey covers around a third of M31's disc in six filters that span from ultraviolet (UV) to near-infrared (NIR). With HST's observing capabilities, the disc of M31, out to 20kpc, is resolved into more than 100 million stars. Dalcanton et al. (2012ApJS..200...18D) chose to observe the northeast quadrant of M31 as it has the least obscured active star-forming regions and least extinction. The spatial coverage selected by the PHAT team also maximized the range of environments and thus stellar evolutionary stages observed. They used two UV filters (F275W and F336W), one optical filter (F475W), one far-red filter (F814W), and two NIR filters (F110W and F160W). The filters were chosen to constrain extinction and effective temperature of a range of stellar populations. To select H{alpha} stars, we used a spectroscopic sample that was collected as part of the SPLASH survey.