<title>Seeing monitor based on wavefront curvature sensing</title>

Abstract

A new wavefront sensing technique called curvature sensing is described. It maps the wavefront total curvature rather than its slope and has been applied to an experimental seeing monitor which detects turbulence induced fast focus fluctuations. Some of the advantages this monitor presents, as compared to DIMM's, are: (1) sensitivity is increased by the use of a circular pupil, (2) the cost is lowered by the use of a photomultiplier, (3) the loss of signal is prevented by the system's fast run, (4) the system runs continuously, and (5) the noise bias is continuously measured and subtracted out.