Image degradation due to surface scatter in the presence of aberrations

Choi, Narak; Harvey, James E.

doi:10.1364/ao.51.000535

Cited by 14 publications

(5 citation statements)

References 19 publications

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“…The surface geometry and roughness establish a value of reflectance that plays an important role when observing objects through a microscope. Accurate reflectance numerical modeling is still a challenging problem, especially in computer graphics for generating realistic images of scenes or for predicting image degradation in optical mirror surfaces, because it requires computational intensive methods like the Beckmann-Kirchhoff theory for rough surface reflectance or the generalized Harvey-Shack surface scatter theory [23,24]. However, the purpose of our simulations is to evaluate the performance of different 3D reconstruction methods under surfaces of variable reflectance.…”

Section: A3 Reflectance Mapsmentioning

confidence: 99%

Robust 3D surface recovery by applying a focus criterion in white light scanning interference microscopy

2018

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White Light Scanning Interference (WLSI) microscopes provide an accurate surface topography of engineered surfaces. However, the measurement accuracy is substantially reduced in surfaces with low reflectivity regions or high roughness, like a surface affected by corrosion. An alternative technique called Shape from Focus (SFF) takes advantage of the surface texture to recover the 3D surface by using a focus metric through a vertical scan. In this work, we propose a technique called SFF-WLSI, which consists in recovering the 3D surface of an object by applying the Tennegrad Variance (TENV) focus metric to WLSI images. Extensive simulation results show that the proposed technique yields accurate measurements under different surface roughness and surface reflectivity outperforming the conventional WLSI and the SFF techniques. We validated the simulation results on two real objects with a Mirau-type microscope. The first, a flat lapping specimen with R a = 0.05 µm for which we measured an average value of R a = 0.055 µm and standard deviation σ = 0.008 µm. The second, a metallic sphere with corrosion which we reconstructed with WLSI versus the proposed SFF-WLSI technique producing a better 3D reconstruction with less undefined depth values. OCIS codes:http://dx.

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Section: A3 Reflectance Mapsmentioning

confidence: 99%

Robust 3D surface recovery by applying a focus criterion in white light scanning interference microscopy

2018

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“…Choi and Harvey [31], showed that, for multi-element imaging systems degraded by both surface scatter and aberrations, the composite PSF is obtained in explicit analytic form in terms of convolutions of the geometrical PSF and scaled BRDFs of the individual surfaces of the imaging system. And a recent parametric analysis of the effect of scattered light upon the MTF of an imaging system discussed in some detail the situations under which Eq.…”

Section: System Mtf In the Presence Of Surface Scattermentioning

confidence: 99%

Effect of surface scatter upon the MTF of the solar ultra violet imager (SUVI) telescope

Harvey¹,

Choi

2013

Solar Physics and Space Weather Instrumentation V

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The solar UV imager (SUVI) is an extreme ultraviolet instrument that will fly on the Geostationary Operational Environmental Satellite (GOES)-R and-S platforms, as part of NOAA's space weather monitoring fleet. It will provide important information on solar activity and the effects of the Sun on the earth and the near-earth environment. This instrument will image the full solar disc in 6 EUV wavebands between 303.8 Å and 93.9 Å. A generalized Cassegrain telescope configuration is employed where six mirror sectors utilize multilayer coatings optimized for the six wavelengths of interest. An aperture shutter is used to select the appropriate sector for observations at a particular wavelength. A thinned, back-illuminated CCD sensor with 21m (2.5 arcsec) pixels resides in the telescope focal plane. The modulation transfer function (MTF) is usually considered to be the image quality criterion of choice for applications where fine detail in extended images needs to be specified or evaluated. However, the contractual image quality requirement was specified in terms of fractional ensquared energy for a variety of different wavelengths and square sizes. In this paper we will calculate and present MTF plots (as degraded by diffraction, geometrical aberrations, surface scatter effects and detector effects) for each of the SUVI wavelengths of interest. Surface scatter due to residual optical fabrication errors is a major factor limiting the performance at the shorter wavelengths, and the large detector size severely limits the performance at all SUVI wavelengths.

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“…The quality of the images captured in professional astronomy is of vital importance to the scientific community, so a high degree of accuracy is required in the technology used to take them [ 1 , 2 , 3 , 4 , 5 ]. This technology, in addition to providing images of the highest possible quality through their respective charge-coupled devices (CCDs), must be able to mitigate all sources of noise that cause a loss of image quality.…”

Section: Introductionmentioning

confidence: 99%

Compensation Techniques Aimed at Mitigating Vibrations in Optical Ground-Based Telescopes: A Systematic Review

Palacios-Navarro

Martínez

Ferrer

et al. 2021

Sensors

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The objective of this study was to evaluate the performance of the different systems and techniques aimed at suppressing vibrations on optical ground-based telescopes. We identified the studies by searching three electronic databases (Science Direct, IEEE library and Web of Science) from the year 2000 to December 2020. The studies were eligible if they proposed systems focused on mitigating the effects of vibrations in optical telescopes and brought performance data. A total of nine studies met our eligibility criteria. Current evidence confirms the feasibility of adaptative optics (AO) systems based on closed-loop control to mitigate vibrations, although variations and additions should be made depending on their nature and characteristics in order to improve the performance of the proposed techniques. This systematic review was conducted to provide a state-of-the-art of the methods and techniques that have been developed over the past two decades. The review also points out some issues that demand future research.

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Image degradation due to surface scatter in the presence of aberrations

Cited by 14 publications

References 19 publications

Robust 3D surface recovery by applying a focus criterion in white light scanning interference microscopy

Robust 3D surface recovery by applying a focus criterion in white light scanning interference microscopy

Effect of surface scatter upon the MTF of the solar ultra violet imager (SUVI) telescope

Compensation Techniques Aimed at Mitigating Vibrations in Optical Ground-Based Telescopes: A Systematic Review

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