  We describe the details of the Hubble Space Telescope (HST) Advanced Camera
for Surveys / Wide Field Channel (ACS/WFC) observations of the COSMOS field,
including the data calibration and processing procedures. We obtained a total
of 583 orbits of HST ACS/WFC imaging in the F814W filter, covering a field that
is 1.64 square degrees in area, the largest contiguous field ever imaged with
HST. The median exposure depth across the field is 2028 seconds (one HST
orbit), achieving a limiting point-source depth AB(F814W) = 27.2 (5 sigma). We
also present details about the astrometric image registration, distortion
removal and image combination using MultiDrizzle, as well as motivating the
choice of our final pixel scale (30 milliarcseconds per pixel), based on the
requirements for weak lensing science. The final set of images are publicly
available through the archive sites at IPAC and STScI, along with further
documentation on how they were produced.
