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Improving wavefront sensing with a Shack–Hartmann device

2016; Optica Publishing Group; Volume: 55; Issue: 28 Linguagem: Inglês

10.1364/ao.55.007836

0003-6935

Martín Rais, Jean‐Michel Morel, Carole Thiébaut, Jean-Marc Delvit, Gabriele Facciolo,

Optical measurement and interference techniques

To achieve higher resolutions, current earth observation satellites use larger, lightweight primary mirrors that can deform over time, affecting the image quality. To overcome this problem, we evaluated the possibility of combining a deformable mirror with a Shack-Hartman wavefront sensor (SHWFS) directly in the satellite. The SHWFS's performance depends entirely on the accuracy of the shift estimation algorithm employed, which should be computationally cheap to execute onboard. We analyzed the problem of fast, accurate shift estimation in this context and have proposed a new algorithm, based on a global optical flow method that estimates the shifts in linear time. Based on our experiments, we believe our method has proven to be more accurate and stable, as well as less sensitive to noise, than all current state-of-the-art methods, permitting a more precise onboard wavefront estimation.