Transcript , ppt

Index of Refraction is many scatterers
Transmitted plus scattered
Scattered radiation cancels out
All energy ends up in forward direction with phase shift proportional to
distance
New wavelength
Scintillation
dim
bright
ground
Adaptive Optics
Adaptive Optics
Adaptive Optics
Scintillation
Refractive Scintillation
Diffraction and resolution
I
n=2
Airy disk
n=1
n=1
n=2
distance
Diffractive Scintillation
Airy disk
1.22 /D distance
I
n=2
n=1
n=1
n=2
distance
Diffractive Scintillation
E
x
I
Diffractive Scintillation
E
x
I
x
For a rarified gas
iφ
iφ
i
<e e j > = 0
2
iΘ
|
<|∑Ai e i > =
When i≠ j
<∑Ai2>
Interferometery and aperture synthesis
 
2ct

2 ~

x sin 

2 ~ ~

x 

x
 ~
2


~


~y 

 2



 

~  x 
   
 y 
At separation , the signal is proportional to:
 e l  d 
~
iA
~
2
~
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