Investigating atmospheric deep turbulence present in digital holography field data

Abstract

In this paper, we investigate the results of a field-test campaign measuring distributed-volume turbulence using a high-frame-rate digital holographic (DH) sensor. Distributed-volume turbulence, or strong turbulence distributed throughout the propagation path, is particularly challenging for DH systems and limits their capabilities. However, previous research has shown that DH systems can measure and correct for the resulting optical aberrations better than traditional wavefront sensors. In a previous test, we captured operationally realistic data sets outside of the laboratory in distributed-volume turbulence. In this paper, we further evaluate the data to determine if the turbulence was truly distributed throughout the path, and we apply the Coherent Plug and Play (CPnP) algorithm with a single phase screen in the pupil plane and with four screens distributed along the path. The single-screen results degrade as the turbulence strengthens, confirming that the conditions were anisoplanatic, while the four-screen results remain focused despite the uplink scintillation present on the illumination beam. Overall, these results demonstrate the operational applicability of the data set and validate an algorithm previously tested only through simulationhigh-frame-rate and laboratory experiments.