WKB initial field - Githubissues

guagua-pamcn / a-dda

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WKB initial field #59

Open GoogleCodeExporter opened 8 years ago

GoogleCodeExporter commented 8 years ago

Use internal field from WKB approximation as an input for the iterative
solver. Should be effective for index-matching particles.

Original issue reported on code.google.com by yurkin on 24 Dec 2008 at 7:56

GoogleCodeExporter commented 8 years ago

This should be implemented (in some form) by the end of 2010.

Original comment by yurkin on 22 Mar 2010 at 6:19

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GoogleCodeExporter commented 8 years ago

Original comment by yurkin on 22 Mar 2010 at 6:23

Added labels: Milestone-2010, Priority-Critical
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GoogleCodeExporter commented 8 years ago

First implementation of the WKB incident field is done by r981, but it has a 
major limitation. It only works for the default incident direction (along the 
z-axis in the particle reference frame). 

Preliminary tests that using this option leads to some acceleration for 
index-matching particles (up to 20% decrease in number of iterations).

Original comment by yurkin on 29 Sep 2010 at 6:15

GoogleCodeExporter commented 8 years ago

Original comment by yurkin on 2 Dec 2010 at 4:40

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GoogleCodeExporter commented 8 years ago

Original comment by yurkin on 22 Apr 2011 at 2:39

Added labels: Milestone-1.2
Removed labels: Milestone-2010

GoogleCodeExporter commented 8 years ago

Currently WKB does not work at all in sparse mode. However, that is probably 
fine, since it is not expected to be a good approximation for sparse objects 
(where no large homogeneous parts are present).

Original comment by yurkin on 4 Feb 2013 at 5:32

GoogleCodeExporter commented 8 years ago

Original comment by yurkin on 4 Feb 2013 at 5:34

Removed labels: Milestone-1.2

GoogleCodeExporter commented 8 years ago

Specific formulae to transform from WKB field to starting vector were slightly 
changed (improved) by r1223.

Original comment by yurkin on 4 May 2013 at 5:17

GoogleCodeExporter commented 8 years ago

It should also be made operational together with -surf

Original comment by yurkin on 25 Sep 2013 at 10:21

GoogleCodeExporter commented 8 years ago

It happens that there are certain ambiguity in definition of the WKB. In 
particular, there may be additional multiplicative factor in the definition of 
the internal field, either 2/(m+1) or 1/sqrt(m). See, e.g.,
Klett JD, Sutherland RA. Approximate methods for modeling the scattering 
properties of nonspherical particles: evaluation of the 
Wentzel-Kramers-Brillouin method. Appl. Opt. 1992;31:373–386. 
http://dx.doi.org/10.1364/AO.31.000373

Should not be imprortant in the limit m->1, but seems worth experimenting with.

Original comment by yurkin on 11 Apr 2015 at 4:30