A general method for baseline-removal in ultrafast electron powder diffraction data using the dual-tree complex wavelet transform

Laurent P René de Cotret; Bradley J Siwick

doi:10.1063/1.4972518

A general method for baseline-removal in ultrafast electron powder diffraction data using the dual-tree complex wavelet transform

Struct Dyn. 2016 Dec 19;4(4):044004. doi: 10.1063/1.4972518. eCollection 2017 Jul.

Authors

Laurent P René de Cotret¹, Bradley J Siwick

Affiliation

¹ Department of Physics, McGill University , 3600 rue University, Montréal, Québec H3A 2T8, Canada.

Abstract

The general problem of background subtraction in ultrafast electron powder diffraction (UEPD) is presented with a focus on the diffraction patterns obtained from materials of moderately complex structure which contain many overlapping peaks and effectively no scattering vector regions that can be considered exclusively background. We compare the performance of background subtraction algorithms based on discrete and dual-tree complex (DTCWT) wavelet transforms when applied to simulated UEPD data on the M1-R phase transition in VO₂ with a time-varying background. We find that the DTCWT approach is capable of extracting intensities that are accurate to better than 2% across the whole range of scattering vector simulated, effectively independent of delay time. A Python package is available.