Data Quality Initialization¶

The Data Quality (DQ) flags track problems in the data. In the initialization step, the PIXELDQ and/or GROUPDQ extension are created. The PIXELDQ extension is filled with information from the static Data Quality mask (Bad Pixel mask reference file) for the input dataset using a bitwise_or function. The GROUPDQ array is initialized to zero. The PIXELDQ extension is a 2-D array that contains the pixel dependent flags that are the same for all groups and integrations within an exposure, while the GROUPDQ extension is a 4-D array that stores flags that can vary from one group or integration to the next and that will be populated by subsequent steps. For more details refer to JWST-STScI-004355 and the calibration pipeline online software documentation in http://ssb.stsci.edu/doc/jwst_git/docs/dq_init/html/.

Test Requirements¶

Requirement	Fulfilled by
The PIXELDQ is initialized with the information from the reference file.	`test_pixeldq_initialization`
The GROUPDQ extensions are added to the data and all values are initialized zero.	`test_groupdq_initialization`
A DQ_DEF extension with the definition of DQ flags should be present in all products.	`test_dq_def_initialization`
Error array is a 4-D array initialized to zero.	`test_err_initialization`

Test Data¶

The dq_init step is applied the same to all instruments and exposure types except the NIRSpec IRS2 mode; therefore, we choose to test one NIRCam FULL frame image and one SUB640 subarray image.

Todo

Need NIRSpec IRS2.

Test Procedure¶

To run these tests the config.json should contain the "dq_init" section for example:

{
    "dq_init": [
        "dq_init/jw82600004001_02101_00001_nrcb1_uncal.fits",
        "dq_init/jw82600011001_02103_00001_nrcb1_uncal.fits"
    ]
}

Using the above config.json simply run:

test_pipeline --config config.json

Reference/API¶

caltest.test_caldetector1.test_dq_init Module¶

Functions¶

`fits_mask`(fits_output)
`fits_output`(fits_input)
`test_dq_def_initialization`(fits_output)	Check that a DQ_DEF extension with the definition of DQ flags is present.
`test_dq_init_step`(fits_input)	Make sure the DQInitStep runs without error.
`test_err_initialization`(fits_output)	Check that the error array is a 4-D array initialized to zero.
`test_groupdq_initialization`(fits_output)	Check that the GROUPDQ extension is added to the data and all values are initialized to zero.
`test_pixeldq_initialization`(fits_output, …)
`translate_dq`(ref_hdul)

Navigation