Stages of Processing

The processing of JWST data goes through three stages. Stage 1 processes the ramps and produces uncalibrated slopes. Stage 2 calibrates the slope images. Stage 3 does processing of ensembles of slopes images.

Pipeline stages

The pipeline has three main stages that provide data to the archive (see Figure 1).  Each stage is composed of multiple steps (aka modules).  The input and output data are given.

  • Stage 1: raw non-destructively read ramps to uncalibrated slope images
    • input: Raw ramps for all integrations.
    • output: Uncalibrated slope images for all integrations and exposures.
    • CALWEBB_DETECTOR1: All data
  • Stage 2: calibrates the individual slope images
    • input: Uncalibrated slope images for all integrations and exposures
    • output: Calibrated slope images for all integrations and exposures
    • CALWEBB_IMAGE2: All imaging data (including coronagraphy and AMI)
    • CALWEBB_SPEC2: All spectroscopic data
  • Stage 3: ensemble processing of slope images
    • input: Calibrated slope images for all integrations and exposures
    • output: level 3 data
    • CALWEBB_IMAGE3: Direct imaging data
      • output: Coadded image(s) (e.g., mosaic). Catalog of sources. Updated exposure level products.
    • CALWEBB_CORON3: Coronagraphic data
      • output: Coadded image(s). Updated exposure level products.
    • CALWEBB_AMI3: NIRISS Aperture Masking Interferometry data
      • output: Fringe parameters.
    • CALWEBB_SPEC3: Spectroscopic data
      • output: Coadded spectral cube. Extracted 1D spectrum. Updated exposure level products.
    • CALWEBB_TSO3: All time series observations (photometry and spectroscopy)
      • output: Photometry and 1D spectroscopy for each integration and exposure. Updated exposure level products.

Figure 1. JWST pipeline structure

The overall JWST pipeline structure and flow is shown. All the data start at the top and the processing becomes more specific to the particular type of observations as the data flow through the pipeline. All modules in the pipeline contribute processed data to the archive. Note that the "CALWEBB_" prefix has been omitted from the module names.

Last updated

Published July 11, 2017