About DrizzlePac


Software for Aligning and Combining HST Images

DrizzlePac is a software package for aligning and combining HST images, which brings an array of new features and algorithmic improvements over the prior, widely used MultiDrizzle software.

Starting in July 2012, all drizzled data products obtained from MAST are produced with AstroDrizzle. An abbreviation for Astrometric Drizzle, AstroDrizzle was designed from the ground-up to substantially improve the handling of distortion in the image header World Coordinate System.

AstroDrizzle removes geometric distortion, corrects for sky background variations, flags cosmic-rays, and combines images with optional subsampling. Drizzled data products from MAST are generated for single visit associations only.

To combine data from additional visits, TweakReg may be used to update the image WCS using matched source lists. Once the full set of images of a given target are properly aligned, they may be combined with AstroDrizzle.

DrizzlePac may be obtained by installing AstroConda. The most recent software versions for both linux and osx are listed here and the latest release notes may be found here.

Instructions for setting up your computing environment to use the DrizzlePac software are described in the following Jupyter Initialization notebook.

Questions may be addressed to the STScI Help Desk website: hsthelp.stsci.edu