Wavefront sensor performance in strong turbulence with an extended beacon

Adaptive optics (AO) systems on airborne platforms must be able to sense fields degraded by strong turbulence such as that associated with long horizontal propagation paths. The self-referencing interferometer (SRI) is a wavefront sensor that has been shown to be insensitive to scintillation. However, the limitations of the SRI have not been fully examined for extended beacons, which may have an angular extent larger than the isoplanatic angle of the atmosphere. This work presents results of computer simulations that examine the open-loop performance of an SRI wavefront sensor using an extended beacon and compares this performance with that of a Shack-Hartmann wavefront sensor.