  The SDSS has been a gold mine for understanding properties of the Milky Way.
Below, in the watershed, there remain small nuggets to be found flowing from
the deepest recesses of the mine. The SDSS-DR9 included the release of the
flux- and wavelength-calibrated, individual spectra which were subsequently
combined to form the composite spectra found in previous SDSS data releases.
These single-epoch spectra (SES) can be analyzed to find flux and spectral line
variability, and to probe aspects of phase variations for objects such as RRL
stars. For $\sim 45%$ of the spectra in the RRL color range, SES were taken on
separate nights, sometimes weeks apart. The remaining dataset have a time
baseline of 0.75 to 1.5 hours and consist of 4-7 separate exposures. In my talk
I will present details of our project to detect variability and to constrain
the pulsation phase at the time of observation. I will discuss our
auto-detection technique that uses division of all SES for a given star to
search for variations in the flux, the hydrogen Balmer lines and the CaII K
line. This procedure is being tested against known variables and non-variable
stars within Stripe 82 to determine the identification effectiveness as a
function of signal-to-noise, RRL type, and time baseline length. I will also
discuss the use of empirical standard star templates to predict pulsation phase
from the combination of hydrogen line strengths and radial velocity variations.
Our ultimate goal is to combine the SES analysis with our new metallicity
calibration in order to increase the number of RRL stars that have reliable
metallicity determinations and which can then be used to probe the structure of
the Milky Way halo.
