Projected Pupil Plane Pattern (PPPP) with artificial Neural Networks
| Autor: | F. J. de Cos Juez, C. Gutierrez, Huizhe Yang, Nazim Ali Bharmal |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Wavefront
Physics 010308 nuclear & particles physics business.industry FOS: Physical sciences Astronomy and Astrophysics Laser 01 natural sciences Collimated light law.invention Root mean square Telescope Laser guide star Optics Space and Planetary Science law Physics - Data Analysis Statistics and Probability 0103 physical sciences Laser power scaling business Adaptive optics Astrophysics - Instrumentation and Methods for Astrophysics Instrumentation and Methods for Astrophysics (astro-ph.IM) 010303 astronomy & astrophysics Data Analysis Statistics and Probability (physics.data-an) |
| Zdroj: | Monthly notices of the Royal Astronomical Society, 2019, Vol.487(1), pp.1480-1487 [Peer Reviewed Journal] WOS:000474907100111 RUO. Repositorio Institucional de la Universidad de Oviedo instname |
| Popis: | Focus anisoplanatism is a significant measurement error when using one single laser guide star (LGS) in an Adaptive Optics (AO) system, especially for the next generation of extremely large telescopes. An alternative LGS configuration, called Projected Pupil Plane Pattern (PPPP) solves this problem by launching a collimated laser beam across the full pupil of the telescope. If using a linear, modal reconstructor, the high laser power requirement ($\sim1000\,\mbox{W}$) renders PPPP uncompetitive with Laser Tomography AO. This work discusses easing the laser power requirements by using an artificial Neural Network (NN) as a non-linear reconstructor. We find that the non-linear NN reduces the required measurement signal-to-noise ratio (SNR) significantly to reduce PPPP laser power requirements to $\sim200\,\mbox{W}$ for useful residual wavefront error (WFE). At this power level, the WFE becomes 160\,nm root mean square (RMS) and 125\,nm RMS when $r_0=0.098$\,m and $0.171$\,m respectively for turbulence profiles which are representative of conditions at the ESO Paranal observatory. In addition, it is shown that as a non-linear reconstructor, a NN can perform useful wavefront sensing using a beam-profile from one height as the input instead of the two profiles required as a minimum by the linear reconstructor. |
| Databáze: | OpenAIRE |
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