Modelling and simulation of mid-spatial-frequency error generation in CCOS

Zhong, Bo; Huang, Hong‐Zhong; Chen, Xianhua; Deng, Wenhui; Wang, Jian

doi:10.1186/s41476-018-0075-y

Cited by 15 publications

(1 citation statement)

References 24 publications

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“…Generally, the MSF errors have predominant features resonating with spatial frequencies comparable to the size of the manufacturing tool. In addition, by looking more in detail at the real manufactured optics, the MSF can have patterns such as raster, periodic features, 42 epicyclic, 43 or circular trails (see Fig. 3).…”

Section: Low-order Distortions and Plate Scale Driftsmentioning

confidence: 99%

Performance and limitations of using ELT and MCAO for 50 μas astrometry

Rodeghiero

Arcidiacono

Pott

et al. 2021

J. Astron. Telesc. Instrum. Syst.

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Multi-conjugated adaptive optics (MCAO) is essential for performing astrometry with the Extremely Large Telescope (ELT). Unlike most of the 8-m class telescopes, the ELT will be a fully adaptive telescope, and a significant portion of the adaptive optics (AO) dynamic range will be depleted by the correction and stabilization of the telescope aberrations and instabilities. MCAO systems are of particular interest for ground-based astrometry since they stabilize the low-order field distortions and transient plate scale instabilities, which originate from the telescope and in the instrument. All instruments have several optical elements relatively far away from the pupil that can potentially challenge the astrometric precision of the observations with their residual mid-spatial frequencies errors. Using a combined simulation of ray tracing and AO numerical codes, we assess the impact of these systematic errors at different field-ofview (FoV) scales and fitting scenarios. The distortions have been assessed at different sky position angles (PA) and indicate that over large FoVs only small PA ranges (AE1 deg to 3 deg) are accessible with astrometric residuals ≤50 μas. A full compliance with the astrometric requirement, at any PA, is achievable for 2 arc sec 2 FoV patches already with a third-order polynomial. The natural partition of the optical system into three segments, i.e., the ELT, the MAORY MCAO module, and the MICADO instrument, resembles a splitting of the astrometric problem into the three subsystems that are characterized by different distortion amplitudes and calibration strategies. The result is a family portrait of the different optical segments with their specifications, dynamic motions, conjugation height, and AO correctability, leading to tracing their role in the bigger puzzle of the 50-μas as astrometric endeavor. © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

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Section: Low-order Distortions and Plate Scale Driftsmentioning

confidence: 99%

Performance and limitations of using ELT and MCAO for 50 μas astrometry

Rodeghiero

Arcidiacono

Pott

et al. 2021

J. Astron. Telesc. Instrum. Syst.

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Evolution of raw meat polarization‐based properties by means of Mueller matrix imaging

Peyvasteh

Попов

Bykov

et al. 2020

Journal of Biophotonics

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The possibilities of using Mueller matrix (MM) imaging polarimetry to assess meat quality have not yet been sufficiently explored. In the current study, the fresh porcine muscles are imaged at room temperature with a wide‐field MM imaging polarimeter over 26 hours to visualize dynamics of tissue optical properties through applying Lu‐Chipman decomposition. The frequency distribution histograms (FDHs) and statistical analysis of the MM elements show prominent changes over time. The wavelength spectra of both total depolarization and scalar retardance have dips at 550 nm whereas their values continuously increase with time; the former is referred to the increase of number of scattering events and decrease of myoglobin absorption in the red part of visible spectra related to meat color and freshness, while the latter is associated with the increase in birefringence and meat tenderness. The obtained results are promising to develop a novel fast noncontact optical technique for monitoring of meat quality.

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