<s>
Light	B-Algorithm
scattering	I-Algorithm
by	I-Algorithm
particles	I-Algorithm
is	O
the	O
process	O
by	O
which	O
small	O
particles	O
(	O
e.g.	O
</s>
<s>
Maxwell	O
's	O
equations	O
are	O
the	O
basis	O
of	O
theoretical	O
and	O
computational	O
methods	O
describing	O
light	O
scattering	O
,	O
but	O
since	O
exact	O
solutions	O
to	O
Maxwell	O
's	O
equations	O
are	O
only	O
known	O
for	O
selected	O
particle	O
geometries	O
(	O
such	O
as	O
spherical	O
)	O
,	O
light	B-Algorithm
scattering	I-Algorithm
by	I-Algorithm
particles	I-Algorithm
is	O
a	O
branch	O
of	O
computational	O
electromagnetics	O
dealing	O
with	O
electromagnetic	O
radiation	O
scattering	O
and	O
absorption	O
by	O
particles	O
.	O
</s>
<s>
In	O
case	O
of	O
more	O
complex	O
geometries	O
and	O
for	O
inhomogeneous	O
particles	O
the	O
original	O
Maxwell	O
's	O
equations	O
are	O
discretized	B-Algorithm
and	O
solved	O
.	O
</s>
<s>
Multiple-scattering	O
effects	O
of	O
light	B-Algorithm
scattering	I-Algorithm
by	I-Algorithm
particles	I-Algorithm
are	O
treated	O
by	O
radiative	O
transfer	O
techniques	O
(	O
see	O
,	O
e.g.	O
</s>
<s>
The	O
FDTD	B-Algorithm
method	O
belongs	O
in	O
the	O
general	O
class	O
of	O
grid-based	O
differential	O
time-domain	O
numerical	O
modeling	O
methods	O
.	O
</s>
<s>
The	O
time-dependent	O
Maxwell	O
's	O
equations	O
(	O
in	O
partial	O
differential	O
form	O
)	O
are	O
discretized	B-Algorithm
using	O
central-difference	O
approximations	O
to	O
the	O
space	O
and	O
time	O
partial	O
derivatives	O
.	O
</s>
<s>
There	O
are	O
codes	O
available	O
to	O
study	O
light	O
scattering	O
in	O
Mie	O
approximation	O
for	O
spheres	B-Application
,	I-Application
layered	I-Application
spheres	I-Application
,	I-Application
and	I-Application
multiple	I-Application
spheres	I-Application
and	O
cylinders	O
.	O
</s>
<s>
The	O
discrete	B-Algorithm
dipole	I-Algorithm
approximation	I-Algorithm
is	O
an	O
approximation	O
of	O
the	O
continuum	O
target	O
by	O
a	O
finite	O
array	O
of	O
polarizable	O
points	O
.	O
</s>
<s>
Ray	B-Algorithm
tracing	I-Algorithm
techniques	O
can	O
approximate	O
light	O
scattering	O
by	O
not	O
only	O
spherical	O
particles	O
but	O
ones	O
of	O
any	O
specified	O
shape	O
(	O
and	O
orientation	O
)	O
so	O
long	O
as	O
the	O
size	O
and	O
critical	O
dimensions	O
of	O
a	O
particle	O
are	O
much	O
larger	O
than	O
the	O
wavelength	O
of	O
light	O
.	O
</s>
<s>
Just	O
as	O
with	O
lenses	O
and	O
other	O
optical	O
components	O
,	O
ray	B-Algorithm
tracing	I-Algorithm
determines	O
the	O
light	O
emanating	O
from	O
a	O
single	O
scatterer	O
,	O
and	O
combining	O
that	O
result	O
statistically	O
for	O
a	O
large	O
number	O
of	O
randomly	O
oriented	O
and	O
positioned	O
scatterers	O
,	O
one	O
can	O
describe	O
atmospheric	O
optical	O
phenomena	O
such	O
as	O
rainbows	B-General_Concept
due	O
to	O
water	O
droplets	O
and	O
halos	O
due	O
to	O
ice	O
crystals	O
.	O
</s>
<s>
There	O
are	O
atmospheric	B-Algorithm
optics	I-Algorithm
ray-tracing	I-Algorithm
codes	I-Algorithm
available	O
.	O
</s>
