Reference File Types

The refpix step only uses the refpix reference file when processing NIRSpec exposures that have been acquired using an IRS2 readout pattern. No other instruments or exposure modes require a reference file for this step.

CRDS Selection Criteria

Refpix reference files are selected by DETECTOR and READPATT.

Reference File Format

A single extension, with a EXTNAME keyword of ‘IRS2’, provides the complex coefficients for the correction, and contains 8 columns ALPHA_0, ALPHA_1, ALPHA_2, ALPHA_3, BETA_0, BETA_1, BETA_2, and BETA_3. The ALPHA arrays contains correction multipliers to the data, and the BETA arrays contains correction multiplier to the reference output. Both arrays have 4 components - one for each sector.