Aihara et al. recently described the eighth release of the data (DR8) from the Sloan Digital Sky Survey. The release is the first from what is called SDSS-III. This phase of SDSS began in August 2008, and uses new instrumentation to focus on Galactic Structure and chemical evolution, and measurements of the baryon oscillation feature in the clustering of galaxies and the quasar Ly forest.
The release includes 5-band imaging of roughly 5200 deg2 in the Southern Galactic Cap, bringing the total footprint of the SDSS imaging to 14,555 deg2, or over a third of the Celestial Sphere — see the sky coverage map.
Montage was used to validate the custom background algorithm used by the Sloan team — their algorithm agree with Montage at the 5% level.