the SEGUE star-selection algorithm (Adelman-McCarthy et al. 2007b) and the SSPP, and during normal SEGUE operation, we have obtained $ugriz$ photometry and medium-resolution (2.3 [Å]{}; $R$ = 2000) spectroscopy for large numbers of stars along lines of sight toward the globular clusters M 13, M 15, and M 2 and the open clusters NGC 2420 and M 67. Below we discuss these photometric and spectroscopic data in more detail.

Photometric Data
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The SDSS obtains scans of the sky using the ARC 2.5m telescope on Apache Point, New Mexico. These data are collected in five broad bands ($u, g, r, i, z$) with central wavelengths 3551, 4686, 6166, 7480, and 8932[Å]{} (Fukugita et al. 1996), respectively, using an imaging array of 30 ($6 \times 5$) 2048 $\times$ 2048 Tektronix CCDs (Gunn et al. 1998). The pixel size is 24 $\mu$m, corresponding to $0.396{''}$ on the sky. A series of software procedures, collectively known as the SDSS PHOTO pipeline (Lupton et al. 2001), processes and reduces the scanned images shortly after data are obtained. As part of these procedures, the instrumental fluxes and astrometric positions (Pier et al. 2003), as well as a determination of whether an object is likely to 