wfc3dash

Helper scripts for WFC3 DASH observations

Installation

Download and instll the code repositories. In the shell command line:

# Separate repository for manipulating raws
git clone https://github.com/gbrammer/reprocess_wfc3.git
cd reprocess_wfc3
python setup.py install
cd ..

# This repository
git clone https://github.com/gbrammer/wfc3dash.git
cd wfc3dash
python setup.py install

Usage

1) First fetch (only) the raw files of a DASHed exposure

For example, `icxe01ucq_raw.fits`, from [GO-14114](http://archive.stsci.edu/cgi-bin/mastpreview?mission=hst&dataid=ICXE01010).

2) Run the pre-processing script in the directory with the raw files

>>> from wfc3dash import process_raw
>>> process_raw.run_all()

This splits the MultiAccum ramp into individual frames that can be used as individual "FLT" exposures, in this example icxe01uc[a-j]_flt.fits. Note that the run_all script also produces the normal calwf3 IMA and FLT files, icxe01ucq_ima.fits and icxe01ucq_flt.fits. The latter will show clearly elongated PSFs for exposures with significant drifts. Note that they will look different than the FLT files provided by MAST becuase they were produced turning off the calwf3 CRCORR processing step, which will reject pixels in sources in unpredictable ways as it drifts throughout the ramp.

3) Process the separate read-level exposures (icxe01uc[a-j]_flt.fits) as you would a normal FLT, with, e.g., TweakReg and AstroDrizzle.