The Algorithms Behind the HPF and NEID Pipeline

Abstract

HPF and NEID are new high-resolution stabilized echelle spectrometers at the forefront of using precision radial velocity techniques to search for terrestrial mass exoplanets. High RV precision requires us to carefully consider the algorithms we use in our data reduction and analysis pipeline in order to avoid information loss, data smoothing, or algorithmic noise. We present a brief overview of a few of the algorithms we have chosen to convert unprocessed 2D echellograms into optimally extracted 1D spectra. These algorithms include the use of 2D interpolation that uses polygon clipping to rectify the curvature of the spectra across the detectors and the ability to fully account for aliasing in under-sampled data on the detector using flat lamp spectra as an empirical measurement of the cross-dispersion profiles used to weight our optimal extractions.