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About WFC3 Data Analysis

The WFC3 Instrument Handbook contains the primary guide to WFC3. It provides a complete description of WFC3, references to more detailed information and examples of anomalies one should be aware of in evaluating the quality of the data.

All HST data are delivered to users through MAST. One can retrieve both raw and calibrated data products from MAST. The calibrated data for WFC3 will have been reprocessed at the time of retrieval to reflect the most up to date calibration files at the time of retrieval. Since the calibration pipeline and the reference files used to carry out the calibration change as the knowledge of the instrument improves, it is generally a good idea to re-retrieve the data when one begins serious work on interpreting the data.

The starting point for understanding data products and the process by which the raw data has been calibrated is the HST Data Handbook. It contains a description of the standard data reduction pipeline for WFC3, the types and importance of the files generated by the pipeline, and information about how to display and process the data further.

Observers may want to calibrate the data themselves to check that the standard reduction produces the information that the want. The HST Data Handbook also explains how to reprocess the raw data files into calibrated data products using the same  routines that are used reduce individual images in the calibration pipeline, and contains a brief introduction to the AstroDrizzle software that allows one to remove the image distortion from individual flat-field images and to combine the (usually) dithered images to produce a final data product.

The intent of the software provided by STScI is to produce data that is calibrated in physical units with instrumental artifacts in so far as possible removed. The data are produced in standard FITS formats, which can be analyzed from within Python, IDL, or a variety of other astronomical packages.

Last Updated: 06/02/2023


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