Improving the accuracy of a Shack-Hartmann wavefront sensor on extended scenes

6th International Workshop on New Computational Methods for Inverse Problems

物理学;计算机科学

Rais, M.^1,2 ; Morel, J.-M.^2 ; Thiebaut, C.^3 ; Delvit, J.-M.^3 ; Facciolo, G.^2,4

TAMI, Universitat des les Illes Balears, Spain^1

CMLA, ENS-Cachan, Université Paris Saclay, France^2

Centre National des Études Spatiales, France^3

LIGM, UMR 8049, Ecole des Ponts, UPE, France^4

关键词: Earth observation satellites;    Global optical flows;    Higher resolution;    Shack-Hartmann wavefront sensors;    Shift estimations;    State-of-the-art methods;    Wave front sensors;    Wavefront estimation;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/756/1/012002/pdf
DOI  :  10.1088/1742-6596/756/1/012002

学科分类：计算机科学（综合）

来源: IOP

【 摘 要 】

In order to achieve higher resolutions, current earth-observation satellites use larger lightweight main mirrors which are usually deformed over time, impacting on image quality. In the context of active optics, we studied the problem of correcting this main mirror by performing wavefront estimation in a closed loop environment. To this end, a Shack-Hartman wavefront sensor (SHWFS) used on extended scenes could measure the incoming wavefront. The performance of the SHWFS on extended scenes depends entirely on the accuracy of the shift estimation algorithm employed, which should be fast enough to be executed on-board. In this paper we specifically deal with the problem of fast accurate shift estimation in this context. We propose a new algorithm, based on the global optical flow method, that estimates the shifts in linear time. In our experiments, our method proved to be more accurate and stable, as well as less sensitive to noise than all current state-of-the-art methods.