Abstract. A new method for restoring images degraded by atmospheric turbulence
where the resulting point spread function varies across the field
of view is discussed. Such cases occur in horizontal imaging
by telescope close to the ground, especially during daytime when
convective turbulence is worst. Each image frame of a captured
movie sequence is exposed for a time short enough to
freeze the effects of the turbulence, resulting in a random
wobble and blurring of the image that is position and
time dependent. Registration of each frame to a reference image
is achieved either by a moving region-of-interest correlation or by
a gradient-based optical flow method. In this paper, we discuss
a new method, replacing correlation by a moving region-of-interest Wiener
filter that came from experiments visualising turbulence in jet plumes.
The resulting shift information is used to dewarp each frame
of the sequence before averaging to provide a result corrected
for motion-blur. Further deblurring is carried out by a variety
of deconvolution techniques. The shift or blur information can also
be used to visualize the intervening atmospheric turbulence.
Related topics:
Image processing, surveillance and target acquisition
View first page of "Fraser: Image Restoration in Horizontal Surveillance by Telescope"
Papers by Fraser
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