YAO(1)							      General Commands Manual							    YAO(1)

NAME

       yao - Adaptive Optics simulation tool in yorick

SYNOPSIS

       Start yao with the gtk GUI:
	  yao parfile.par
	  yorick -i yaopy.i parfile.par

       Within yorick (no GUI, but same graphical output)
	  #include yao.i
	  aoread,"parfile.par"; aoinit; aoloop; go;

DESCRIPTION

       Yao  is	a  monte-carlo	simulation  package  for adaptive optics. It includes fast core coded in C (e.g. wavefront sensing) that are glued
       together by yorick interpreted code. One defines the system to evaluate using a configuration file, and then run aoread, aoinit and aoloop.
       Yao features:

       *  Shack-Hartmann and Curvature WFS, on or off axis.

       *  Stackarray (piezostack), curvature (bimorph), modal (zernike) and Tip-Tilt deformable mirrors are supported. The altitude of conjugation
	  is adjustable.

       *  An arbitrary number of WFSs and DMs can be selected, with the possibility of mixing types. It is therefore possible (and easy) to  simu-
	  late single DM systems, as well as single non-zero conjugate, GLAO and MCAO systems.

       *  It supports Natural and Laser Guide Stars (or a mix), WFS with photon and read-out noise.

       *  It uses a multi-layered atmospheric model, with geometrical propagation only.

       *  The  loop  execution	has been optimized for speed: the critical routines have been coded in C. Yorick is thus used as a convenient glue
	  between lower levels optimized C calls. Overall, this is rather efficient: A simple 6x6 Shack-Hartmann system runs at up to  650  itera-
	  tions  per  second on an apple dual 2GHz G5 (200 iterations/sec for a full diffraction propagation model). A 50x50 Shack-Hartmann system
	  runs at about 3 iterations/s. A 188 curvature system runs at 25 iterations/s.

       *  Straightforward scriptability to probe parameter domains.

       *  GTK GUI to change some of the system parameters while the loop is running (new in v4.0). This provides an educational approach to  Adap-
	  tive	Optics	(newbies  can  play  with  the parameters and immediately sees how the system reacts) and can also provides a quick way to
	  investigate the stability conditions for a newly designed system, before entering more serious Monte-carlo simulations.

   Options
	help,aoread   will give you information about the syntax, parameters and keywords of aoread. See help,aoinit and help,aoloop also.

AUTHOR

       Francois Rigaut, Gemini Observatory

FILES

       Input files:

       parfile.par    A yao parameter file. This file follows a regular yorick syntax. It is directly included by yorick to define the	structures
		      used  by	yao.  As  it might be a little bit daunting to create a parfile from scratch, example parfiles are provided. Their
		      location depends on the installation. Search for yao/examples (e.g. shx6x.par, curvature.par)

       screen*.fits   To simulate the atmospheric turbulence, yao needs phase screens. You can create phase screens  with  create_phase_screens().
		      They might also be included in your distribution.

       Output files:

       parfile.res    After a simulation run, results are output in parfile.res in the cwd

BUGS

       Lots.

       LGS uplink propagation is not implemented

       Shack-Hartmann cross talk between subapertures is not implemented

       Many more.

SEE ALSO

       yorick(1)

4th Berkeley Distribution					 2007 December 12							    YAO(1)