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Speckle Interferometry

Speckle interferometry allows the reconstruction of high resolution diffraction-limited images. Due to atmospheric turbulences, the image resolution (seeing) degrades even for large telescopes to about 1 arcsec at visible wavelengths. However, the theoretical diffraction-limited angular resolution is given by lamda/D. For example the diffraction limit for observations at 600 nm wavelength at a telescope of 6 m diameter is 0.02 arcsec, a factor of 50 better than the seeing limit.

The planar wave coming from an object is deformated by the atmosphere, which results in constructive and destructive interference on the imaging sensor - the so called speckles. For short exposure times the atmospheric turbulences are "frozen" and the high resolution information without atmospheric effects can be reconstructed from the speckles. However, a large number of short exposure images is required to reconstruct the final diffraction-limited high-resolution two-dimensional real image.

Speckle interferometry imposes special requirements on the equipment, such as low noise, low power and fast readout. To fulfill these requirements our department developed the optics, electronics and software for our speckle interferometry observations.


Test Object classes:
extragalactic objects,
young stellar objects,
evolved stars

Atmosphere Atmosphere

Telescope Telescope:
2.2m, 3.6m, SAO, NTT, MMT

Optic Optics:
Optics developed by our group
Imaging sensors Imaging sensors:
Electronic Electronics:
Readout Electronics developed by our group
Online Software Online Software:
MoDAS software developed by our group
Reduktion Software Data Reduction Software:
Building Block by our research group
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