Response of the dispersed and temporal group delay estimators (solid and dashed lines respectively) to an OPD ramp x_GD in the H-band. The ideal response is represented by the large gray line. In all cases, the coherence envelope has a sinc shape. Top: the envelope model is a sinc function. Bottom: the envelope model is a parabola. Figures on the right are a zoom on the central part of the left-hand side figures. The DR limits are represented with blue arrows on the top-left plot in the ideal case for both estimators.