Star point centroid algorithm based on background forecast

2014 ◽  
Author(s):  
Jin Wang ◽  
Rujin Zhao ◽  
Nan Zhu
Keyword(s):  
Centroid Algorithm ◽  
Background Forecast

Fringe order identification in optical fibre white-light interferometry using centroid algorithm method

1992 ◽  
Vol 28 (6) ◽  
pp. 553 ◽  
Author(s):  
S. Chen ◽  
A.W. Palmer ◽  
K.T.V. Grattan ◽  
B.T. Meggitt
Keyword(s):  
Optical Fibre ◽  
White Light ◽  
White Light Interferometry ◽  
Fringe Order ◽  
Centroid Algorithm

Median based algorithm for sub-pixel estimation of extrema positions of diffuse light reflection signal

2021 ◽  
Vol 2021 (49) ◽  
pp. 37-44
Author(s):  
I. B. Ivasiv ◽  
Keyword(s):  
Linear Array ◽  
Piecewise Linear ◽  
Linear Interpolation ◽  
Diffuse Light ◽  
Random Errors ◽  
Centroid Algorithm ◽  
Piecewise Linear Interpolation ◽  
Light Reflectance ◽  
Cumulative Function

It has been proposed to utilize the median algorithm for determination of the extrema positions of diffuse light reflectance intensity distribution by a discrete signal of a photodiode linear array. The algorithm formula has been deduced on the base of piecewise-linear interpolation for signal representation by cumulative function. It has been shown that this formula is much simpler for implementation than known centroid algorithm and the noise immune Blais and Rioux detector algorithm. Also, the methodical systematic errors for zero noise as well as the random errors for full common mode additive noises and uncorrelated noises have been estimated and compared for mentioned algorithms. In these terms, the proposed median algorithm is proportionate to Blais and Rioux algorithm and considerably better then centroid algorithm.

scholarly journals Ensemble-Based Targeted Observation Method Applied to Radar Radial Velocity Observations on Idealized Supercell Low-Level Rotation Forecasts: A Proof of Concept

2020 ◽  
Vol 148 (3) ◽  
pp. 877-890 ◽  
Author(s):  
Christopher A. Kerr ◽  
Xuguang Wang
Keyword(s):  
Decision Making ◽  
Radial Velocity ◽  
Variance Reduction ◽  
Sampling Error ◽  
Error Variance ◽  
Low Level ◽  
Optimal Ensemble ◽  
Targeted Observation ◽  
Background Forecast ◽  
Full Volume

Abstract The potential future installation of a multifunction phased-array radar (MPAR) network will provide capabilities of case-specific adaptive scanning. Knowing the impacts adaptive scanning may have on short-term forecasts will influence scanning strategy decision-making in hopes to produce the most optimal ensemble forecast while also benefiting human severe weather warning decision-making. An ensemble-based targeted observation algorithm is applied to an observing system simulation experiment (OSSE) where the impacts of synthetic idealized supercell radial velocity observations are estimated before the observations are “collected” and assimilated. The forecast metric of interest is the low-level rotation forecast metric (0–1-km updraft helicity), a surrogate for tornado prediction. It is found that the ensemble-based targeted observation approach can reasonably estimate the true error variance reduction when an effective method that treats sampling error is applied, the period of model forecast is associated with less degrees of nonlinearity, and the observation information content relative to the background forecast is larger. In some scenarios, a subset of a full-volume scan assimilation produces better forecasts than all observations within the full volume. Assimilating the full-volume scan increases the number of potential spurious correlations arising between the forecast metric and radial velocity observation induced state perturbations, which may degrade the forecast metric accuracy.

scholarly journals A Sub-pixel Centroid Algorithm for Star Image Based on Gaussian Distribution

2011 ◽  
Vol 53 (182) ◽  
pp. 307-310
Author(s):  
Jing SUN ◽  
Guangrui LI ◽  
Desheng WEN ◽  
Bin XUE ◽  
Shaodong YANG
Keyword(s):  
Gaussian Distribution ◽  
Star Image ◽  
Centroid Algorithm
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