DKIST/CryoNIRSP: Level 1 Data Calibration Methods

The Cryogenic Near-Infrared Spectropolarimeter (Cryo-NIRSP) is a first light instrument now conducting science operations at the National Science Foundation’s Daniel K. Inouye Solar Telescope (DKIST). It is a combination slit-based spectrograph and context-imaging instrument optimized for polarimetric observations of spectral band-passes between 1 and 5 microns. Its science mission focuses on the solar corona and longwave solar disk. Here we discuss the calibration methods and related metrology data that support the creation of Level 1 science data from diverse operational modes. This includes the detector calibrations applied to up-the-ramp sampling modes of the H2RG infrared detectors, flat fielding methods, polarization calibration, photometric calibration, and initial corrections for background scattered light. We also discuss new ad hoc methods for coronal polarimetric calibration and/or validation. These methods support the routine calibration of CryoNIRSP data at the DKIST Data Center.