Fast Fourier Transform Techniques for Measuring SEM Resolution

1990 ◽  
Vol 48 (1) ◽  
pp. 406-407 ◽  
Author(s):  
A. Dodson ◽  
D. C. Joy
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Fast Fourier Transform ◽  
Surface Structure ◽  
Spatial Resolution ◽  
Instrumental Performance ◽  
Performance Limits ◽  
Maximum Resolution ◽  
Accurate Interpretation ◽  
Precise Knowledge

Precise knowledge of a particular SEM's resolution is important for at least two reasons to the microscopist operating the instrument. First, accurate interpretation of micrographs obtained in the course of daily operation depends on knowing the performance limits of the instrument. Second, it is important for the microscopist to be able to verify instrumental performance.Spatial resolution is typically determined using micrographs of materials containing structures having a “known” spacing. By showing that two objects in the micrograph are separated by some distance, it is claimed that the instrument is capable of resolving this spacing. This method is passable for instruments whose maximum resolution resolves only features of known spacing. However, for High Resolution SEM's (HRSEM) this method is not adequate. It is difficult to identify specimens with surface structure that can be verified to exist at the ultimate limits of today's HRSEM resolution. The fact that verifying resolution by this method depends on being able to verify the spacing of surface structure on a particular specimen leads to an interesting paradox - the resolution of a given instrument can be verified only after a better instrument is available to characterize the structure spacing.

Chemical Nano-tomography of Self-assembled Ge-Si:Si(001) Islands from Quantitative High Resolution Transmission Electron Microscopy

2009 ◽  
Vol 1184 ◽  
Author(s):  
Luciano Andrey Montoro ◽  
Marina Leite ◽  
Daniel Biggemann ◽  
Fellipe Grillo Peternella ◽  
Kees Joost Batenburg ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Three Dimensional ◽  
Precise Knowledge ◽  
Transmission Electron ◽  
Self Consistent ◽  
Chemical Distribution

AbstractThe knowledge of composition and strain with high spatial resolution is highly important for the understanding of the chemical and electronic properties of alloyed nanostructures. Several applications require a precise knowledge of both composition and strain, which can only be extracted by self-consistent methodologies. Here, we demonstrate the use of a quantitative high resolution transmission electron microscopy (QHRTEM) technique to obtain two-dimensional (2D) projected chemical maps of epitaxially grown Ge-Si:Si(001) islands, with high spatial resolution, at different crystallographic orientations. By a combination of these data with an iterative simulation, it was possible infer the three-dimensional (3D) chemical arrangement on the strained Ge-Si:Si(001) islands, showing a four-fold chemical distribution which follows the nanocrystal shape/symmetry. This methodology can be applied for a large variety of strained crystalline systems, such as nanowires, epitaxial islands, quantum dots and wells, and partially relaxed heterostructures.

scholarly journals High-resolution wide-band fast Fourier transform spectrometers

2012 ◽  
Vol 542 ◽  
pp. L3 ◽  
Author(s):  
B. Klein ◽  
S. Hochgürtel ◽  
I. Krämer ◽  
A. Bell ◽  
K. Meyer ◽  
...  
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Fast Fourier Transform ◽  
Wide Band

scholarly journals Analisis Misalignment Citra Multispektral Terhadap Citra Pankromatik Pada Data Worldview-2

2018 ◽  
Vol 15 (1) ◽  
Author(s):  
Randy Prima Brahmantara ◽  
Kustiyo Kustiyo
Keyword(s):  
Fourier Transform ◽  
Fast Fourier Transform ◽  
Spatial Resolution ◽  
Multispectral Image ◽  
Phase Matching ◽  
Standard Data ◽  
Measurement Results ◽  
Standard Level ◽  
Fourier Transform Phase ◽  
Level 2

The standard data of Worldview-2 owned by LAPAN is Ortho-Ready Standard level 2 (OR2A) data consisting of 4 multispectral bands (blue, green, red, NIR) and one panchromatic band each 2 m and 0,5 m spatial resolution. Both images have different metadata and RPC, making it possible to perform geometric corrections separately. This paper discusses the analysis of the inaccuracies of multispectral image positions to panchromatic images compared to those that have been systematically geometric corrected. The method used is fast fourier transform phase matching by taking 500 binding points between the two images. The measurement results prove that the multispectral image of the Worldview-2 data of the OR2A level has a larger shift compared with multispectral image that has been systematically geometric corrected. The multispectral image of the OR2A data shifts are 2,14 m on the X-axis and 0,42 m on the Y-axis. While the multispectral image that has been systematically geometric corrected shifts are 1,72 m on the X-axis and 0,54 m on the Y-axis.ABSTRAKData standar Worldview-2 yang dimiliki oleh LAPAN merupakan data Ortho-Ready Standard level 2 (OR2A) yang terdiri dari 4 kanal multispektral (biru, hijau, merah, NIR) dan satu kanal pankromatik masing-masing memiliki resolusi spasial 2 meter dan 0,5 meter. Kedua kanal tersebut memiliki metadata dan RPC yang berbeda, sehingga memungkinkan untuk melakukan koreksi geometrik secara terpisah. Tulisan ini membahas tentang analisis misalignment citra multispektral terhadap citra pankromatik dibandingkan dengan yang telah terkoreksi geometrik sistematik. Metode yang digunakan adalah fast fourier transform phase matching dengan mengambil 500 titik ikat antara kedua citra tersebut. Hasil pengukuran membuktikan bahwa citra multispektral data Worldview-2 level OR2A memiliki pergeseran yang lebih besar dibandingkan dengan citra multispektral yang terkoreksi geometrik sistematik. Citra multispektral data OR2A bergeser 2,14 meter pada sumbu X dan 0,42 meter pada sumbu Y. Sedangkan citra multispektral data terkoreksi geometrik sistematik bergeser 1,72 meter pada sumbu X dan 0,54 meter pada sumbu Y.

Comparative analysis of function of the optical spacecraft Earth's remote sensing based on the ratio between the mass of the satellite and the maximum spatial resolution of the target equipment

2017 ◽  
Vol 920 (2) ◽  
pp. 46-56
Author(s):  
O.S. Sizov
Keyword(s):  
Remote Sensing ◽  
High Resolution ◽  
Spatial Resolution ◽  
Regression Function ◽  
Statistical Sampling ◽  
Maximum Resolution ◽  
Sensing Systems ◽  
High Resolution Imagery ◽  
Remote Sensing Systems ◽  
Analysis Of Function

The paper analyzes the development of the technical capabilities of civil optical satellite ERS with a spatial resolution higher than 10 m/pix. On the basis of the ratio between the mass of the spacecraft and the maximum resolution of target equipment is offered hyperbolic regression function that describes the average specification for remote sensing systems with varying degrees of detail. The statistical sampling includes all the civil remote sensing satellites with high and ultra-high resolution, functioning on the orbit at the beginning of May 2016. The analysis on the effectiveness of missions completed their existence, as well as progressive devices and constellations, is conducted by using the obtained function. The data of existing and planned national remote sensing satellites are compared. Author made brief conclusions about the main trends of development of the world›s optical segment of high resolution imagery, as well as about the matching of the Russian group ERS evolution plans to observed trends.

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