Spectral Classification and Redshift Measurement for the SDSS-III Baryon Oscillation Spectroscopic Survey

We describe the automated spectral classification, redshiftdetermination, and parameter measurement pipeline in use for the BaryonOscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky SurveyIII (SDSS-III) as of the survey's ninth data release (DR9), encompassing831,000 moderate-resolution optical spectra. We give a review of thealgorithms employed, and describe the changes to the pipeline that havebeen implemented for BOSS relative to previous SDSS-I/II versions,including new sets of stellar, galaxy, and quasar redshift templates.For the color-selected "CMASS" sample of massive galaxies at redshift0.4 ~ z ~ 0.8 targeted by BOSS for the purposes of large-scalecosmological measurements, the pipeline achieves an automated