15 GHz Monitoring of CGRaBS Blazar Candidates with the OVRO 40-meter Telescope in Support of Fermi

Since mid-2007, we have monitored 1200 blazar candidates at 15 GHz with the 40-Meter Telescope at the Owens Valley Radio Observatory. These sources include the 1158 sources above -20 degrees declination from the Candidate Gamma-Ray Blazar Survey (CGRaBS) catalog. These sources have been observed at least every two days, providing well-sampled radio light curves. These are being used to study radio variability and to cross correlate with gamma-ray observations from the Fermi Gamma-ray Space Telescope. (See poster by Max-Moerbeck et al for details of the variability studies.) The 15 GHz fluxes in our sample range from 10 mJy to 30 Jy, with a median of 300 mJy. We have achieved 5 mJy thermal noise and approximately 1.6% systematic flux uncertainty. We discuss here the observation program, data reduction, and calibration methods used to achieve this level of performance.