%0 Journal Article
%T Characterization of Optical Aberrations  Induced by Thermal Gradients and  Vibrations via Zernike and Legendre  Polynomials
%A Igor Di Varano
%J Optics and Photonics Journal
%P 113-123
%@ 2160-889X
%D 2016
%I Scientific Research Publishing
%R 10.4236/opj.2016.66014
%X For every
astronomical instrument, the operating conditions are undoubtedly different
from those defined in a setup experiment. Besides environmental conditions, the
drives, the electronic cabinets containing heaters and fans introduce
disturbances that must be taken into account already in the preliminary design
phase. Such disturbances can be identified as being mostly of two types: heat
sources/sinks or cooling systems responsible for heat transfer via conduction,
radiation, free and forced convection on one side and random and periodic vibrations
on the other. For this reason, a key role already from the very beginning of the
design process is played by integrated mod<span>el
merging the outcomes based on a Finite Element Model from thermo-structural and
modal </span>analysis into the optical model to estimate the aberrations. The
current paper presents the status of such model, capable of analyzing the
deformed surfaces deriving from both thermo-structural and vibrational analyses
and measuring their effect in terms of optical aberrations by fitting them by
Zernike and Legendre polynomial fitting respectively for circular and
rectangular apertures. The independent contribution of each aberration is
satisfied by the orthogonality of the polynomials and mesh uniformity.
%K FEM
%K Wavefront Error
%K Zernike
%K Legendre Polynomials
%K Astronomical Instrumentation
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=67761