Effectiveness of iterative algorithms in recovering phase in the presence of noise.
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.
Williams
Garth
G
Department of Physics, University of Illinois, Urbana, IL 61801, USA. g.williams@physics.unimelb.edu.au
Pfeifer
Mark
M
Vartanyants
Ivan
I
Robinson
Ian
I
D000465:Algorithms; D003198:Computer Simulation; D006046:Gold / Q000737:chemistry; D012815:Signal Processing, Computer-Assisted; D014961:X-Ray Diffraction / Q000379:methods*
D006046:Gold