scholarly journals Optimal ellipsometric parameter measurement strategies based on four intensity measurements in presence of additive Gaussian and Poisson noise

2018 ◽  
Vol 26 (26) ◽  
pp. 34529 ◽  
Author(s):  
Xiaobo Li ◽  
François Goudail ◽  
Haofeng Hu ◽  
Qun Han ◽  
Zhenzhou Cheng ◽  
...  
Keyword(s):  
Poisson Noise ◽  
Parameter Measurement ◽  
Ellipsometric Parameter ◽  
Intensity Measurements ◽  
Measurement Strategies

scholarly journals The effect of noise, a constant background, and bit depth on the phase retrieval of pure phase objects

2021 ◽  
Vol 51 (2) ◽  
Author(s):  
Varis Karitans ◽  
Andrejs Tokmakovs ◽  
Adele Antonuka
Keyword(s):  
Root Mean Square Error ◽  
White Noise ◽  
Test Object ◽  
Phase Retrieval ◽  
Poisson Noise ◽  
Mean Square ◽  
Intensity Measurements ◽  
Pure Phase ◽  
Diffraction Patterns ◽  
Different Levels

In the current study, we investigate the effect of uniform white noise, Poisson noise and a constant background on the phase retrieval of pure phase objects. We also study the influence of the aforementioned factors on phase retrieval at different bit depths of intensity measurements. An algorithm called PhaseLift is used for phase retrieval as it requires a small number of modulating masks and can retrieve the phase of an object from sparse intensity measurements of low bit depth. A test object is modulated by eight random masks generated from a single mask and the phase of the object is retrieved from coded diffraction patterns. Different levels of uniform white noise, Poisson noise and constant background are superimposed on the diffraction patterns and the root-mean-square error (RMSE) of the retrieved object is calculated at each level. The results suggest that Poisson noise and a constant background at the same level cause similar RMSE compared to uniform white noise. Lowering the bit depth from 18-bits to 14-bits resulted in the decrease of the RMSE caused by Poisson noise and a constant background. We conclude that the effects of noise and constant background can be reduced by lowering the bit depth.

Thickness and composition determinations from T.E.M. specimens using both x-ray and backscattered electron data

1984 ◽  
Vol 42 ◽  
pp. 576-577
Author(s):  
M.D. Ball ◽  
H. Lagace ◽  
M.C. Thornton
Keyword(s):  
Electron Microscope ◽  
Atomic Number ◽  
Transmission Electron Microscope ◽  
Convenient Method ◽  
Flow Chart ◽  
X Ray ◽  
Intensity Measurements ◽  
Transmission Electron ◽  
Electron Intensity ◽  
Backscattered Electron

The backscattered electron coefficient η for transmission electron microscope specimens depends on both the atomic number Z and the thickness t. Hence for specimens of known atomic number, the thickness can be determined from backscattered electron coefficient measurements. This work describes a simple and convenient method of estimating the thickness and the corrected composition of areas of uncertain atomic number by combining x-ray microanalysis and backscattered electron intensity measurements.The method is best described in terms of the flow chart shown In Figure 1. Having selected a feature of interest, x-ray microanalysis data is recorded and used to estimate the composition. At this stage thickness corrections for absorption and fluorescence are not performed.

Detection of a Pairwise-Correlated Stream of Signals Against a Poisson Noise Background

1999 ◽  
Vol 53 (7-8) ◽  
pp. 69-78
Author(s):  
A. I. Strelkov ◽  
O. M. Stadnyk ◽  
S. I. Kalmykov ◽  
A. P. Lytyuga
Keyword(s):  
Poisson Noise ◽  
Noise Background

Aerodynamic parameter measurement using the wind driven manipulator - Inverse force measurement on wings

1997 ◽  
Author(s):  
Richard Ames ◽  
Richard Ames ◽  
N. Komerath ◽  
J. Magill ◽  
N. Komerath ◽  
...  
Keyword(s):  
Force Measurement ◽  
Parameter Measurement ◽  
Aerodynamic Parameter ◽  
Inverse Force
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