2.3 Data Storage Requirements

The sizes of WFC3 data files (in MB) are given in Table 2.7. The following assumptions were made when calculating these sizes:

  • the ERR, DQ, SAMP, and TIME arrays are null in the raw files,
  • the SAMP and TIME arrays are null in the ima files,
  • IR images have the maximum of 16 MultiAccum readouts, and
  • images are full-frame and unbinned.

Table 2.7: Sizes of WFC3 data files.

ChannelSize of FITS file







35 MB

168 MB

217 MB


34 MB

168 MB

17 MB

13 MB

The size of the drizzled image (_drz) is for a single image that is drizzled only for the purpose of performing geometric corrections and for combining the two UVIS chips. It assumes that the input and output image pixels are approximately the same size (drizzle scale parameter is 1.0).