Noise effects induced by laser guide star (LGS) elongation have to be considered globally in a multi-LGS tomographic reconstruction analysis. This allows a fine estimation of performance and the comparison of different launching options. We present a modal analysis of the wavefront error with Shack–Hartmann wavefront sensors based on quasi-analytical matrix formalism. Including spot elongation and the Rayleigh fratricide effect, edge launching produces similar performance to central launching and avoids the risk of possible underestimation of fratricide scatter. Performance improves slightly with an optimized centroid estimator and is not affected by a slight field-of-view truncation of the subapertures. Finally we discuss detector characteristics for a LGS Shack–Hartmann wavefront sensor.
© 2010 Optical Society of America
Original Manuscript: April 1, 2010
Manuscript Accepted: June 18, 2010
Published: September 22, 2010
Clélia Robert, Jean-Marc Conan, Damien Gratadour, Laura Schreiber, and Thierry Fusco, "Tomographic wavefront error using multi-LGS constellation sensed with Shack–Hartmann wavefront sensors," J. Opt. Soc. Am. A 27, A201-A215 (2010)