A Precision Photometric Comparison between SDSS-II and CSP Type Ia
  Supernova Data
  Consistency between Carnegie Supernova Project (CSP) and SDSS-II supernova
(SN) survey ugri measurements has been evaluated by comparing SDSS and CSP
photometry for nine spectroscopically confirmed Type Ia supernova observed
contemporaneously by both programs. The CSP data were transformed into the SDSS
photometric system. Sources of systematic uncertainty have been identified,
quantified, and shown to be at or below the 0.023 magnitude level in all bands.
When all photometry for a given band is combined, we find average magnitude
differences of equal to or less than 0.011 magnitudes in ugri, with rms scatter
ranging from 0.043 to 0.077 magnitudes. The u band agreement is promising, with
the caveat that only four of the nine supernovae are well-observed in u and
these four exhibit an 0.038 magnitude supernova-to-supernova scatter in this
filter.
