Correção de turbulência: óptica adaptativa

Abstract

When taking astronomical photographs it is needed a long exposure with low brightness. The atmospheric turbulence interferes on the light wavefront coming from celestial bodies. It is possible to correct this distortion through adaptive optics technique. The main objective of this final paper was to study the correction of the atmosphere turbulence and develop a low cost system using this technique. This project was implemented in an optical bench, in which, the system captures an image (through a webcam) coming from a fake celestial body simulated by a laser and corrects its position. The correction of the image is fulfilled by a two-axis mobile mirror (Tip-Tilt) moved by two step motors connected to an Arduino and aided by a software. The Matlab software performs the mirror movement’s control, and a PI controller was implemented. The Matlab, also works as wavefront sensor and sends the needed data, so that, the Arduino can process, and finally, move the mirror adjusting the bright spot to the image center position. From the project development, it was possible to obtain good results, taking into account the limitations due to the search for low cost components.