Part II: STIS Data Handbook

Chapter 3:
STIS Calibration

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3.1 Pipeline Processing Overview
3.2 Structure of calstis
3.3 Data Flow Through calstis
3.4 Descriptions of Calibration Steps
    3.4.1 ATODCORR: Analog to Digital Conversion Correction
    3.4.2 BACKCORR: 1-D Spectral Background Subtraction
    3.4.3 BIASCORR: Small Scale Bias Subtraction
    3.4.4 BLEVCORR: Large Scale Bias & Overscan Subtraction
    3.4.5 CRCORR: Cosmic Ray Correction
    3.4.6 CTECORR: Correction for Charge Transfer Inefficiency Losses
    3.4.7 DARKCORR: Dark Signal Subtraction
    3.4.8 DISPCORR: Apply Dispersion Solution
    3.4.9 DOPPCORR: Correct Reference Files for Doppler Shift
    3.4.10 DQICORR: Initialize Data Quality File
    3.4.11 EXPSCORR: Retain Individual CR-SPLIT Exposures
    3.4.12 FLATCORR: Flat Field Correction
    3.4.13 FLUXCORR: Conversion to cgs Flux
    3.4.14 GEOCORR: Geometric Distortion Correction
    3.4.15 GLINCORR and LFLGCORR: Nonlinearity Corrections
    3.4.16 HELCORR: Correction to Heliocentric Reference Frame
    3.4.17 LORSCORR: Conversion to Native Format MAMA Pixels
    3.4.18 PHOTCORR: Populate Photometry Header Keywords
    3.4.19 RPTCORR: Sum Repeated MAMA Observations
    3.4.20 SC2DCORR: Echelle Scattered Light Correction
    3.4.21 SGEOCORR: Small Scale Distortion Correction
    3.4.22 SHADCORR: CCD Shading Correction
    3.4.23 WAVECORR: Wavecal Correction
    3.4.24 X1DCORR: Locate and Extract 1-D Spectrum
    3.4.25 X2DCORR: Produce Rectified 2-D Spectral Image
3.5 Recalibration of STIS Data
    3.5.1 Mechanics of Full Recalibration
    3.5.2 Rerunning Subsets of the Calibration Pipeline
    3.5.3 Improving the Treatment of Hot Pixels
    3.5.4 Improving Cosmic Ray Rejection
    3.5.5 Removing Fringes from Near-IR Spectral Data
    3.5.6 Using GO Wavecals
    3.5.7 Correcting the Orientation of Spectral Traces
3.6 Updates to calstis

This chapter describes how the STIS pipeline at STScI calibrates incoming STIS data. We begin with a high level overview of the STIS calibration process, and subsequent sections describe the pipeline calibration steps and methodology in successively greater detail. We then discuss several reasons why you might want to recalibrate your data, and how to use the pipeline tasks for recalibration.