Understanding Systematics in ZZ Ceti Model Fitting to Enable   Differential Seismology
  We are conducting a large spectroscopic survey of over 130 Southern ZZ Cetis with the Goodman Spectrograph on the SOAR Telescope. Because it employs a single instrument with high UV throughput, this survey will both improve the signal-to-noise of the sample of SDSS ZZ Cetis and provide a uniform dataset for model comparison. We are paying special attention to systematics in the spectral fitting and quantify three of those systematics here. We show that relative positions in the $\log{g}$-$T_{\rm eff}$ plane are consistent for these three systematics. 
J.T. Fuchs, Bart H. Dunlap, J.C. Clemens, J.A. Meza, E. Dennihy, D.   Koester
astro-ph.SR