Effectiveness of iterative algorithms in recovering phase in the presence of noise

DOI: 10.1107/S0108767306047209
PMID: 17179605

Authors: Garth Williams (University of Illinois) , Mark Pfeifer (University of Illinois) , Ivan Vartanyants (University of Illinois) , Ian Robinson (University of Illinois)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Acta Crystallographica Section A Foundations Of Crystallography , VOL 63 , PAGES 36 - 42

State: Published (Approved)
Published: January 2007

Abstract: Inversion of coherent X-ray diffraction patterns allows the imaging of three-dimensional density distributions. The recovery of such shapes often requires application of iterative algorithms, such as Fienup's error reduction or hybrid input/output. Since the measurement of such a pattern records the intensity in reciprocal space, any errors due to noise will probably not have a straightforward impact on the final real-space result. In this paper, the effect of the types of noise common in coherent X-ray diffraction (CXD) experiments, counting statistics, scatter from alien particles and detector noise, on the recovered real-space density projection is explored by simulating a two-dimensional CXD pattern and adding noise. It is found that an R factor measuring the reproducibility between the best and second-best real-space result is a leading indicator of performance.

Journal Keywords: Iterative Algorithms; Noise; Phase Recovery

Subject Areas: Physics

Facility: APS