Context. The differential optical transfer function (dOTF) is a model-independent image-based wavefront sensor for measuring the complex pupil field (phase and amplitude). This method is particularly suitable for compensating ...

We report atmospheric turbulence parameters, namely atmospheric seeing, tilt-anisoplanatic angle (θ0) and coherence time (τ0), measured under various sky conditions, at Vainu Bappu Observatory in Kavalur. Bursts of short ...