Resolution: a survey

Dekker, Arnold J. den; Bos, A. van den

doi:10.1364/josaa.14.000547

Cited by 372 publications

(191 citation statements)

References 72 publications

(75 reference statements)

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“…It was found that, without the use of the monochromator, Young's fringes only reached to about 70 pm. For a discussion of the relationship between information transfer and resolution, see den Dekker & van den Bos (1997), Van Aert et al (2006) and Peng et al (2008), and for a discussion of the use of Young's fringes to measure information transfer, see Barthel & Thust (2008). …”

Section: Instrument Parameters and Performancementioning

confidence: 99%

Background, status and future of the Transmission Electron Aberration-corrected Microscope project

Dahmen

Erni

Radmilović

et al. 2009

Phil. Trans. R. Soc. A.

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The strong interaction of electrons with small volumes of matter make them an ideal probe for nanomaterials, but our ability to fully use this signal in electron microscopes remains limited by lens aberrations. To bring this unique advantage to bear on materials research requires a sample space for electron scattering experiments in a tunable electron-optical environment. This is the vision for the Transmission Electron Aberrationcorrected Microscope (TEAM) project, which was initiated as a collaborative effort to re-design the electron microscope around aberration-correcting optics. The resulting improvements in spatial, spectral and temporal resolution, the increased space around the sample and the possibility of exotic electron-optical settings will enable new types of experiments. This contribution will give an overview of the TEAM project and its current status, illustrate the performance of the TEAM 0.5 instrument, with highlights from early applications of the machine, and outline future scientific opportunities for aberration-corrected microscopy.Keywords: aberration correction; depth sectioning; monochromator; single-atom detection; light atom imaging; electron microscopy Overview of the Transmission Electron Aberration-corrected Microscope projectRecent advances in aberration-correcting electron optics have led to increased resolution, sensitivity and signal-to-noise (S/N) ratio in atomic resolution microscopy. These advances have created the opportunity to directly observe the atomic-scale order, electronic structure and dynamics of individual nanoscale objects by advanced transmission electron microscopy (TEM). To take advantage of this opportunity, the Transmission Electron Aberration-corrected Microscope (TEAM) project was initiated to optimize the electron microscope around aberration-corrected electron optics and to further advance the limits of the instrument and the technique. The project brings together several leading microscopy groups supported by the US Department of Energy's (DOE's) Office *Author for correspondence (udahmen@lbl.gov).One contribution of 14 to a Discussion Meeting Issue 'New possibilities with aberration-corrected electron microscopy'. http://www.science.doe.gov). After its completion, the instrument will be made available to the scientific user community at the National Center for Electron Microscopy (NCEM).The vision for the TEAM project is the idea of providing a sample space for electron scattering experiments in a tunable electron-optical environment by removing some of the constraints that have limited electron microscopy until now. The resulting improvements in spatial, spectral and temporal resolution, the increased space around the sample and the possibility of setting up novel electronoptical configurations will enable new types of experiments in electron scattering. The TEAM microscope will feature unique corrector elements for spherical and chromatic aberrations, a novel atomic-force-microscopy-inspired specimen stage, a high-brightness gun and numerous other in...

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Section: Instrument Parameters and Performancementioning

confidence: 99%

Background, status and future of the Transmission Electron Aberration-corrected Microscope project

Dahmen

Erni

Radmilović

et al. 2009

Phil. Trans. R. Soc. A.

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“…The second section of the paper focuses on the analytical derivation and analysis of the Angular Resolution Limit (ARL) [21], which is the minimal separation between two closely located targets at which they can be resolved separately. Deriving the ARL of a radar system is a fundamental problem [23] and has previously been formulated in a clutter free environment [21]. This paper considers multipath channels.…”

Section: Introductionmentioning

confidence: 99%

Time reversal MIMO radar: Improved CRB and Angular Resolution Limit

Foroozan

Asif

Boyer

2013

2013 IEEE International Conference on Acoustics, Speech and Signal Processing

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The paper derives closed form (nonmatrix) expression for the deterministic Cramér-Rao bound (CRB) for the direction-of-arrival associated with a target embedded in a noisy, multipath channel using the time reversal (TR) MIMO system. By incorporating the TR built-in adaptive waveform processing feature to reshape the MIMO probing signals, we prove that the CRBs for the direction of arrival can be improved in ways not foreseen with the conventional MIMO radars. A second contribution of the paper is the analytical derivation of the Angular Resolution Limit (ARL) defined as the minimal separation between two targets to be separately resolved by the MIMO radar. At high signal-to-noise ratio, we show that the TR ARL inherits the properties of the TR CRB and is superior to its conventional counterpart by a factor proportional to the order of the channel multipath.

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“…Since resolution is not unambiguously defined, various interpretations have been proposed during the last two centuries, most of them originally introduced in the field of optics [19,20,21]. The natural analogy between acoustics and optics is explored in this section to derive the most popular resolution criteria using a well-defined technique such as acoustic beamforming.…”

Section: Resolution Criteriamentioning

confidence: 99%

Spatial resolution limits for the localization of noise sources using direct sound mapping

Comesaña

Holland

Fernández-Grande

2016

Journal of Sound and Vibration

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One of the main challenges arising from noise and vibration problems is how to identify the areas of a device, machine or structure that produce significant acoustic excitation, i.e. the localization of main noise sources. The direct visualization of sound, in particular sound intensity, has extensively been used for many years to locate sound sources. However, it is not yet well defined when two sources should be regarded as resolved by means of direct sound mapping. This paper derives the limits of the direct representation of sound pressure, particle velocity and sound intensity by exploring the relationship between spatial resolution, noise level and geometry. The proposed expressions are validated via simulations and experiments. It is shown that particle velocity mapping yields better results for identifying closely spaced sound sources than sound pressure or sound intensity, especially in the acoustic near-field.

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Resolution: a survey

Abstract: Past and present approaches to the concept of optical resolution are reviewed.

Cited by 372 publications

References 72 publications

Background, status and future of the Transmission Electron Aberration-corrected Microscope project

Background, status and future of the Transmission Electron Aberration-corrected Microscope project

Time reversal MIMO radar: Improved CRB and Angular Resolution Limit

Spatial resolution limits for the localization of noise sources using direct sound mapping

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