kderp (KCWI Data Extraction and Reduction Pipeline) reduces data for the Keck Cosmic Web Imager. Written in IDL, it performs basic CCD reduction on raw images to produce bias and overscan subtracted, gain-corrected, trimmed and cosmic ray removed images; it can also subtract the sky. It defines the geometric transformations required to map each pixel in the 2d image into slice, postion, and wavelength, and performs flat field and illumination corrections. It generates cubes, applying the transformations previously solved to the object intensity, variance and mask images output from any of the previous stages, and uses a standard star observation to generate an inverse sensitivity curve which is applied to the corresponding observations to flux calibrate them.

This pipeline has been superseded by KCWI_DRP (ascl:2301.019).

KCWI_DRP, written in Python and based on kderp (ascl:2301.018), is the official DRP for the Keck Cosmic Web Imager at the W. M. Keck Observatory. It provides all of the functionality of the older pipeline and has three execution modes: multi-threading for CPU intensive tasks such as wavelength calibration, and multi-processing for large datasets. It offers vacuum to air and heliocentric or barycentric correction and the ability to use KOA file names or original file names. KCWI_DRP also improves the provenance and traceability of DRP versions and execution steps in the headers over kderp, and has versatile sky subtraction modes including using external sky frames and ability of masking regions.