In version 1 of the HDF processed data, CRREJ itself was used for
combining the frames a stack with the same dither position.
Weights were proportional to the exposure time, which is nearly
optimal for the F814W and F606W, but not for the F450W and F303W
images, which have a significant read-noise contribution.
A different weighting scheme is being adopted for version 2.
Copyright © 1997 The Association of Universities for
Research in Astronomy, Inc. All Rights Reserved.
Harry Ferguson
ferguson@stsci.edu
1/14/96