Simulation of SOAR AO

Guide stars Tip-tilt Low-order AO (21 Zernike) High-order AO (66 Zernike)
1 NGS soartt soar1 soar1hm
3 NGSs soarttt soar2 and soar4 soar2h
1 Rayleigh LGS - - soar1hr
3 Rayleigh LGSs - - soar2hra
1 Sodium LGS - - soar1hs

Test points: 0 - un-compensated, 1 - on-axis. The positions of other points are listed in the files as distance from the center of FoV and position angle.

Parameters: Strehl ratio, FWHM in X,Y directions, FWHE = 50% encircled energy diameter, EDD = equivalent detectivity diameter (gives relative gain in background-limited magnitude), Fried resolution (gives increase in central PSF intensity compared to atmosphere with infinite outer scale).

Turbulence model for Cerro Pachon is specified by the Fried parameter r0 (at 0.5 micron), by outer scale parameter L0, and by the vertical distribution (7 discrete layers with altitudes and relative energies listed). Influence of outer scale on FWHM of un-compensated seeing images can be seen in soartt.txt.

Simulations were done with the modal covariance code (IDL) and approximate PSF-estimation procedure. The cases of several guide stars (natural, laser, mixed) and several deformable mirrors can be treated. By changing the test points and weights, some optimization of PSF over the field is possible.