Abstract
Adaptive Optics (AO) is one of the techniques to reduce aberrations caused by
atmosphere turbulence in the light coming from objects above this layer that
reaches ground based optical telescopes. It was proposed 62 years ago, and
since then it has undergone a fast evolution due to the technical developments
in mechanics, optics and electronics. Due to these advances and the efforts of
the research community, AO nowadays is widely used in big and moderate size
telescopes and it has become an essential instrument in this telescope segment.
The research for its use in small aperture telescopes has been limited for different
factors: it is an expensive technique; small aperture involves less gathered light
that could reduce AO performance; and also low altitudes where usually these
telescopes are located result in severe aberrations. This research has been focused in
the investigation of new techniques and procedures that facilitate the engineering
of an AO system for small aperture telescopes.
For this purpose an AO testbed has been developed, which includes a portable
opto-mechanical platform adapted specifically for its use in small aperture
telescopes, which has been tested in laboratory and assessed with on-sky
experiments.
In this research, an original AO real time processing control architecture has
been defined, that can be fully implemented in a low cost standalone Field
Programmable Gate Array (FPGA) device, unlike standard AO configurations,
which typically rely in complex distributed hardware architectures which make
the system more expensive and less portable.
The lack of gathered light inherent to small aperture telescopes constitutes a
severe limitation for an AO system. Hence is crucial to develop optimized
image processing algorithms that balance this drawback. Here a novel fast
implementation of a centroiding algorithm has been accomplished, adapted to
severe low light conditions, and from this a closed loop AO system has been
demonstrated.
There is wide potential demand in the scientific and amateur astronomy
community in this field, and the innovations and engineering concepts introduced
here constitute a valid and proven AO system applied for small aperture telescopes.