The LBT will provide a deformable secondary mirror for AO observations. For this reason the ETC can handle both a seeing-limited PSF and a diffraction-limited PSF (1.2.3). If the loop is closed, different Strehl ratios are possible. This depends on the environmental conditions (seeing, ...). Therefore the value of this parameter is continously changeable.
Andre Germeroth
2016-11-04
