The Photometric Survey

5 broad-band filters ( u', g', r', i', z’ )

limiting magnitudes (22.3, 23.3, 23.1, 22.3, 20.8)

drift scan of 10,000 square degrees

55 sec exposure time

40 TB raw imaging data -> pipeline ->

100,000,000 galaxies

50,000,000 stars

calibration to 2% at r'=19.8

only done in the best seeing (20 nights/yr)

pixel size is 0.4 arcsec, astrometric precision is 60 milliarcsec

Southern Galactic Cap

multiple scans (> 30 times) of the same stripe

Continuous data rate of 8 Mbytes/sec