STScI . ... Data . ... Calibration . ... The drizzle software requires only the distortion correction files indicated in your image headers (keywords IDCTAB and OFFTAB), which can also be downloaded individually from the STScI uref directory. ... Output files : set build=no to generate separate files for science image (drz_sci.fits) and exposure weight map (drz_weight.fits). ... Intermediate files : set clean=no to keep the intermediate files that are helpful while verifying your output and iterating. ...