Sensing Quasi-Static Aberrations of Adaptive Optics Systems On-Line with Long-Exposure Phase DiversityL. M. Mugnier, J.-F. Sauvage, T. Fusco, S. Dandy and A. Cornia1st AO4ELT conference - Adaptive Optics for Extremely Large Telescopes, (2010) 05006DOI: https://doi.org/10.1051/ao4elt/201005006