FFTW is a powerful Fast Fourier Transform (FFT) library available under the
terms of the GNU General Public License. Source files have been extracted from
the original package to be used in the context of the NAOS project. Files
which are not useful have not been included in the present distribution. FFT
facilities provided by this library are used by NAOS both on workstation and
LCU.

On workstation, FFT is used during performance estimation by the NAOS
Preparation Software (PS). Simulations are carried out to reconstruct an
estimation of the point-spread function provided by the NAOS adaptive optics
system in given conditions. The use of fast Fourier transform algorithms is
essential due to the heavy use of the PS during preparation phase.

The point-spread function is also reconstructed in real-time during the
observation, and this task is performed on LCUs, thus the relevant software
module is also provided for compiling on VxWorks platform.

The home site for FFTW is http://www.fftw.org/. Documentation about the
library is provided in this module in HTML and PostScript format. Read the
INSTALL file for instructions and comments about the generation of the source
files from the original package.
