Analysis of atmospheric wavefront distortions from PICTURE, a balloon-based optical telescope

PICTURE-D is a NASA balloon mission intended to directly image debris disks in nearby star systems. The observatory floats at altitudes up to 40km, above 99% of Earth’s atmosphere. This greatly reduces the effects of atmospheric turbulence and seeing, allowing for much more stable stellar wavefronts. To counteract turbulence, most modern optical telescopes utilize various adaptive optics (AO) systems. Many AO systems observe the incoming signal with wavefront sensors and aim to correct the effects of atmospheric distortion in near real-time with deformable mirrors. Although greatly reduced by altitude, PICTURE-D must still contend with these distortions as well as effects from thermal and mechanical deformations and imperfections in optical components. During three flights in 2019, 2022 and 2025, the mission has collected a vast amount of wavefront sensor data, detailing exactly what errors were present and at what times. We present an analysis of the wavefront distortions and attempt to connect them to various sources both interior to the instrument and exterior from the atmosphere. Emphasis is placed on atmospheric turbulence and the simulation of atmospheric distortions at high altitudes. The feasibility of AO corrections is also discussed, centering on the size of distortions and the timescale over which they vary.