Advanced DFS: a dispersed fringe sensing algorithm insensitive to small calibration errors

Dispersed Fringe Sensing (DFS) is an elegant method of coarse phasing segmented mirrors. DFS performance accuracy is dependent upon careful calibration of the system as well as other factors such as internal optical alignment, system wavefront errors, and detector quality. Novel improvements to the algorithm have led to substantial enhancements in DFS performance. In this paper, we present Advanced DFS, an advancement of the DFS algorithm, which allows the overall method to be less sensitive to calibration errors. This is achieved by correcting for calibration errors, which appear in the fitting equations as a signal phase term. This paper will outline a brief analytical explanation of the improvements, results of advanced DFS processed simulations and experimental advanced DFS results.