Adaptive optics is new technology which removes
the atmospheric tremor and helps the astronomer see
the image through earth based telescopes more
Without using this system the image obtained in
telescope on earth would be blur, which is caused by
the turbulent mixing of air at different temperature.
It brings together the latest in computers, materials
science, electronic detectors and digital control in a
system that warps and bends a mirror in a telescope to
counteract in real time the atmospheric distortion.
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Telescopes are instruments used to study the
electromagnetic radiations from the universe.
The word telescope is derived from the Greek
words “tele” (from afar)and “skopos” (viewer).
The principle of all telescopes is to gather radiation
from distant objects and focus it. This increases the
intensity of the radiations thereby allowing the
objects to be magnified.
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5. THREE DIFFERENT TYPES OF
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6. Optical Telescopes
An optical telescope is a telescope that gathers
and focuses light, mainly from the visible part of the
electromagnetic spectrum, to create a magnified image for
Optical telescopes have been used in astronomical
research since the time of their invention in the early 17th
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8. Reflecting Telescopes
A reflecting telescope (also called a reflector) is
a telescope that uses a single or a combination
of curved mirrors that reflect light and form
The reflecting telescope was invented in the 17th
century, by Isaac Newton.
Reflecting telescopes come in many design
It may employ extra optical elements to improve
image quality or place the image in a
mechanically advantageous position.
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10. Radio Telescopes
A radio telescope is a specialized antenna and radio
receiver used to receive radio waves from astronomical radio
sources from the sky .
Radio telescopes are the main observing instrument used in
radio astronomy, which studies the radio frequency
portion(wave portion) of the electromagnetic
spectrum emitted by astronomical objects.
Radio telescopes are typically large parabolic ("dish")
antennas similar to those employed in tracking and
communicating with satellites and space probes. They may
be used singly or linked together electronically in an array.
Unlike optical telescopes, radio telescopes can be used in the
daytime as well as at night.
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12. What isAdaptive optics ?
Adaptive optics refers to optical system, which adapt to
compensate the optical effects introduced by the medium
between the object and its image.
In order to avoid atmospheric tremor one can turn to
large telescope on the ground, which have been equipped
with ADAPTIVE OPTICS system.
With this setup, the image quality thus formed would be as
if the telescope is in space
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13. BASIC PRINCIPLES
An adaptive system refracts the wave fronts by reflecting
the light of a deformable mirror whose shape is changed in
real time to introduce an equal but opposite distortion.
The information on how to distort the mirror comes from a
wave front sensor (an instrument that measures optical
tremor imposed by the atmosphere on light from a star).
After the light reflects of the deformable mirror, a beam
splitter sends part of the light to a camera that will capture
the high resolution image produced by the adaptive optics.
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There are many substantial technological challenges in AO
such as development of fast & very low-noise detectors in
order to be able to correct with fainter reference stars;
deformable mirror with bandwidths of actuators and
large secondary adaptive mirror etc.
The latter i.e. adaptive optics, are especially interesting at
thermal wave lengths, where any additional mirror raises
the already huge thermal background seen by the
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