Photometry using the Infrared Array Camera on the Spitzer Space Telescope

We present several corrections for point-source photometry to be applied to data from the Infrared Array Camera (IRAC) on the Spitzer Space Telescope. These corrections are necessary because of characteristics of the IRAC arrays and optics and the way the instrument is calibrated in flight. When these corrections are applied, it is possible to achieve a similar to 2% relative photometric accuracy for sources of adequate signal-to-noise ratio in an IRAC image.