Processing Levels and Product Stages

Here we describe the structure and content of the most frequently used forms of files for Roman science data products, which are in ASDF format. Each type of ASDF file is the result of serialization of a corresponding DataModel. All data models are defined by their schemas.

Within the various STScI internal data processing and archiving systems that are used for routine processing of Roman data, there are some different uses of terminology to refer to different levels of processing. The WFI data is converted into ASDF files by Science Data Formatting (SDF), level 0. SDF also inserts data from the engineering database and from the proposal database to create the level 1 files. SDF produces one ASDF file per detector and exposure and these level 1 files are used as input to the Exposure Level Processing. The output of the exposure level processing is a level 2 file.

Data Processing Levels	User Data Product Stages	MAST Product
Level 0, Science telemetry	Not available to users	Not available to users
Level 1, Uncalibrated files	Level 1 - ASDF file, fully populated by SDF	1 - Uncalibrated exposures
Exposure Level Processing	Level 2 - Fully calibrated exposures	2 - Calibrated exposures
High Level Processing	Level 3 - Combined data	3 - Combined data
High Level Processing	Level 4 - Catalogs, segmentation images	4 - Combined data

Level 1 and Level 2 products packaged the data from individual detectors in a single ASDF file. Level 3 are data resampled on a sky cell. The definitions of the sky cells is TBD. The definition of Level 3 and Level 4 products is being finalized.