scholarly journals Geometric quality assessment of CBERS-4 MUXCAM image

2016 ◽  
Vol 4 (2) ◽  
pp. 116
Author(s):  
Thiago Statella
Keyword(s):  
Spatial Resolution ◽  
Ccd Camera ◽  
High Accuracy ◽  
Fourth Generation ◽  
Multispectral Images ◽  
Geometric Correction ◽  
Positional Accuracy ◽  
Geometric Quality ◽  
Better Than

In December 2014, Brazil and China successfully launched the CBERS-4 satellite, the fourth generation of CBERS satellites. In the payload module, the satellite carries the MUXCAM, a 20 m/pixel spatial resolution multispectral camera. The MUXCAM was built by Brazil and it is an improvement of the CCD camera on board CBERS-1, 2 and 2B satellites. In this paper the geometric quality of the MUXCAM images is analyzed. One can measure the geometric quality of the CCD sensor by calculating the positioning and the internal accuracy of the images acquired by it. The positional accuracy for the MUXCAM resulted in ~404 m whereas the internal accuracy resulted in ~30 m, better than 2 pixels. Therefore, in less rigorous applications in which a high accuracy in coordinates is not mandatory, and in which such errors can be neglected, the multispectral images acquired by MUXCAM can be used without a prior geometric correction.    

scholarly journals ANALYSIS OF SPOT-6 DATA FUSION USING GRAM-SCHMIDT SPECTRAL SHARPENING ON RURAL AREAS

2014 ◽  
Vol 10 (2) ◽  
Author(s):  
Danang Surya Candra
Keyword(s):  
Data Fusion ◽  
Spatial Resolution ◽  
Rural Areas ◽  
Signal To Noise Ratio ◽  
Test Site ◽  
Multispectral Images ◽  
Fused Image ◽  
Pc Method ◽  
Better Than

Image fusion is a process to generate higher spatial resolution multispectral images by fusion of lower resolution multispectral images and higher resolution panchromatic images. It is used to generate not only visually appealing images but also provide detailed images to support applications in remote sensing field, including rural area. The aim of this study was to evaluate the performance of SPOT-6 data fusion using Gram-Schmidt Spectral Sharpening (GS) method on rural areas. GS method was compared with Principle Component Spectral Sharpening (PC) method to evaluate the reliability of GS method. In this study, the performance of GS was presented based on multispectral and panchromatic of SPOT-6 images. The spatial resolution of the multispectral (MS) image was enhanced by merging the high resolution Panchromatic (Pan) image in GS method. The fused image of GS and PC were assessed visually and statistically. Relative Mean Difference (RMD), Relative Variation Difference (RVD), and Peak Signal to Noise Ratio (PSNR) Index were used to assess the fused image statistically. The test sites of rural areas were devided into four main areas i.e., whole area, rice field area, forest area, and settlement. Based on the results, the visual quality of the fused image using GS method was better than using PC method. The color of the fused image using GS was better and more natural than using PC. In the statistical assessment, the RMD results of both methods were similar. In the RVD results, GS method was better then PC method especially in band 1 and band 3. GS method was better than PC method in PSNR result for each test site. It was observed that the Gram-Schmidt method provides the best performance for each band and test site. Thus, GS was a robust method for SPOT-6 data fusion especially on rural areas.

A method of precise misorientation determination

2003 ◽  
Vol 36 (6) ◽  
pp. 1319-1323 ◽  
Author(s):  
A. Morawiec
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Spatial Resolution ◽  
Standard Procedure ◽  
Good Spatial Resolution ◽  
Transmission Electron ◽  
Order Of Magnitude ◽  
Achievable Accuracy ◽  
Better Than

A method that improves the accuracy of misorientations determined from Kikuchi patterns is described. It is based on the fact that some parameters of a misorientation calculated from two orientations are more accurate than other parameters. A procedure which eliminates inaccurate elements is devised. It requires at least two foil inclinations. The quality of the approach relies on the possibility to set large sample-to-detector distances and the availability of good spatial resolution of transmission electron microscopy. Achievable accuracy is one order of magnitude better than the accuracy of the standard procedure.

Quantitative structural analysis of fractures using digital outcrop models

2020 ◽  
Author(s):  
Caroline Modica Custódio ◽  
Maria Alcione Lima Celestino ◽  
Laís Vieira de Souza ◽  
Jaqueline Lopes Diniz ◽  
Leonardo Campos Inocencio ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Visual Inspection ◽  
High Accuracy ◽  
Northeastern Brazil ◽  
Preferential Orientation ◽  
Positional Accuracy ◽  
Cloud Models ◽  
The Difference ◽  
Digital Outcrop ◽  
Quantitative Approaches

<p><span xml:lang="PT-BR" data-contrast="auto"><span>The use of digital outcrop models (DOMs) in geosciences has been increasingly common since the beginning of the 2000s due to the technological advances in the positional and image-quality field equipment, data collection, and processing with practicality, agility, and high accuracy even in inaccessible sites. DOMs incorporate all the visual elements that geoscientists analyze in the outcrops as 3D models with a spatial resolution of a few millimeters per pixel and positional accuracy of less than 2 cm. The great advantage of DOMs is their daily availability for visual inspection and interpretation in the office, complementing the data analysis performed in the field. Therefore, the continuous development of high accuracy and dense image-based and point cloud models has been crucial for quantitative approaches using digital models. Another challenge in this process involves the development of tools and methodologies for interpretation of DOMs, especially analysis and interpretation of linear and planar features such as lineations, paleocurrents, joints, faults, and deformation bands. This study aims to systematize the manual and semi-automatic methods of plane extraction using tools (e.g., Compass and Facets) available in the open-source software such as the CloudCompare, and statistically analyze the structural measurements from the extracted data. In this work, we analyzed two 3D integrated ground-UAV photogrammetric models reconstructed with the Structure from Motion (SfM) technique. The study areas are part of the Araripe Basin basement, located in Northeastern Brazil, and represent two case studies involving joints and faults associated with the damage zone of the boundary fault. Initial results obtained by the automatic planes measured with the Facets plugin show distinct fracturing patterns. This is mainly due to the difference of the rock rheology and competence. In the metasedimentary outcrop, we identified 731 planes in phyllites, reduced to </span><span>459 real</span><span> planes after noise remotion and visual inspection during interpretation. In this case, the data accuracy is 62% for plane recognition. The preferential orientation is N40-90E and N40-80W, with high dip angles, and subordinately N45E and N10W with low dip angles. In the metatonalite, 347 planes were recognized, but only 38 of them showed to be real planes, totalizing accuracy of 10,9%. The planes validated </span><span>as real</span><span> indicate a preferential orientation of N10-15W with high angles of dip. Both outcrops used the same processing routine and configuration. The difference observed in the number of planes automatically recognized in each outcrop is a consequence of the relationship between the plane orientation x outcrop orientation, spatial resolution of the model, and the degree of weathering. Besides that, positional accuracy and visual quality are crucial for accurate quantitative interpretation of structural features using digital outcrop models, as well as a well-defined data processing routine and careful inspection of the results by an expert. The data obtained from this methodological approach will contribute to quantitative approaches in structural geology based on robust datasets.</span></span><span> </span></p>

EBSD With FEGSEM - Issues, Advances and Applications

1999 ◽  
Vol 5 (S2) ◽  
pp. 240-241 ◽  
Author(s):  
F.J. Humphreys ◽  
I. Brough
Keyword(s):  
Spatial Resolution ◽  
Ccd Camera ◽  
Beam Current ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Subgrain Structure ◽  
Direction Parallel ◽  
Diffraction Patterns ◽  
Equiaxed Grains ◽  
Better Than

A standard commercial EBSD system, comprising a CCD camera (Nordif) and acquisition software (HKL Technology) has been interfaced to a Philips XL30 FEGSEM, and the spatial and angular resolutions for EBSD compared with a conventional W-filament JEOL 6300 SEM equipped with a similar EBSD system.In characterising a grain or subgrain structure, overlapping diffraction patterns are obtained at the boundaries, and the effective spatial resolution can be defined as the distance over which the patterns cannot be solved. The spatial resolution is best in the direction parallel to the specimen tilt axis (LA), typically some three times better than for the direction perpendicular to the axis. The resolution is conveniently determined by measuring the fraction of patterns which are solved (Ns) during a raster scan of the sample. For a microstructure of equiaxed grains of size D, LA is given approximately by D(1-Ns)/4. Figure 1 is a plot of Ns against D−1 for aluminium samples under optimum operating conditions, and it is seen that the spatial resolution in the FEGSEM is some three times better than in the W-filament SEM.The effect of beam current on LA is shown in figure 2. For the W-filament SEM, LA is a strong function of the probe current.

Orientation Maps Derived from TEM Diffraction Patterns Collected with an External CCD Camera

2005 ◽  
Vol 495-497 ◽  
pp. 197-202 ◽  
Author(s):  
Edgar F. Rauch ◽  
A. Duft
Keyword(s):  
Spatial Resolution ◽  
Crystallographic Orientation ◽  
Low Cost ◽  
Ccd Camera ◽  
Transmission Electron ◽  
Fluorescent Screen ◽  
Orientation Maps ◽  
Electron Microscopes ◽  
Diffraction Patterns ◽  
Better Than

An automatic crystallographic orientation indexing procedure is developed for transmission electron microscopes. The numerical identification is performed by mapping the spot diffraction patterns with pre-calculated templates. The diffraction patterns are acquired thanks to an external CCD camera that points to the fluorescent screen through the TEM window. Orientation maps with spatial resolution better than 10 nm were obtained with this low cost equipment.

scholarly journals ASTEP South: An Antarctic Search for Transiting Planets around the celestial South pole

2008 ◽  
Vol 4 (S253) ◽  
pp. 336-339
Author(s):  
N. Crouzet ◽  
K. Agabi ◽  
A. Blazit ◽  
S. Bonhomme ◽  
Y. Fanteï-Caujolle ◽  
...  
Keyword(s):  
Extrasolar Planets ◽  
Ccd Camera ◽  
Giant Planets ◽  
Field Of View ◽  
South Pole ◽  
Temperature Variations ◽  
Transiting Planets ◽  
A Site ◽  
Better Than

AbstractASTEP South is the first phase of the ASTEP project that aims to determine the quality of Dome C as a site for future photometric searches for transiting exoplanets and discover extrasolar planets from the Concordia base in Antarctica. ASTEP South consists of a front-illuminated 4k × 4k CCD camera, a 10 cm refractor, and a simple mount in a thermalized enclosure. A double-glass window is used to reduce temperature variations and the associated turbulence on the optical path. The telescope is fixed and observes a 4° × 4° field of view centered on the celestial South pole. With this design, A STEP South is very stable and observes with low and constant airmass, both being important issues for photometric precision. We present the project, we show that enough stars are present in our field of view to allow the detection of one to a few transiting giant planets, and that the photometric precision of the instrument should be a few mmag for stars brighter than magnitude 12 and better than 10 mmag for stars of magnitude 14 or less.

scholarly journals Pansharpening by Complementing Compressed Sensing with Spectral Correction

2020 ◽  
Vol 10 (17) ◽  
pp. 5789
Author(s):  
Naoko Tsukamoto ◽  
Yoshihiro Sugaya ◽  
Shinichiro Omachi
Keyword(s):  
High Resolution ◽  
Compressed Sensing ◽  
Spatial Resolution ◽  
High Spectral Resolution ◽  
Multispectral Images ◽  
Spectral Distortion ◽  
Ringing Artifacts ◽  
Corrected Intensity ◽  
Component Substitution ◽  
Better Than

Pansharpening (PS) is a process used to generate high-resolution multispectral (MS) images from high-spatial-resolution panchromatic (PAN) and high-spectral-resolution multispectral images. In this paper, we propose a method for pansharpening by focusing on a compressed sensing (CS) technique. The spectral reproducibility of the CS technique is high due to its image reproducibility, but the reproduced image is blurry. Although methods of complementing this incomplete reproduction have been proposed, it is known that the existing method may cause ringing artifacts. On the other hand, component substitution is another technique used for pansharpening. It is expected that the spatial resolution of the images generated by this technique will be as high as that of the high-resolution PAN image, because the technique uses the corrected intensity calculated from the PAN image. Based on these facts, the proposed method fuses the intensity obtained by the component substitution method and the intensity obtained by the CS technique to move the spatial resolution of the reproduced image close to that of the PAN image while reducing the spectral distortion. Experimental results showed that the proposed method can reduce spectral distortion and maintain spatial resolution better than the existing methods.

scholarly journals ANALYSIS OF THE USE OF TECHNOLOGY SYNCHRONOUS DIGITAL HIERARCHY SDH

2019 ◽  
Author(s):  
Л.К. Хаджиева ◽  
М.Л. Сатуева
Keyword(s):  
Quality Of Service ◽  
Network Performance ◽  
High Accuracy ◽  
Modern Technology ◽  
Synchronous Digital Hierarchy ◽  
Use Of Technology ◽  
Network Topologies ◽  
Design Analyses ◽  
Better Than

Ввиду быстрого прогресса в современных технологиях и огромной потребности в увеличении пропускной способности для использования современных средств требуется более сложная топология сети для обеспечения лучшего качества обслуживания (QoS). Эти требования, в свою очередь, предполагают высокую точность проектирования и совершенство метода синхронизации. Целью данного исследования является решение способа преодоления вышеуказанной проблемы путем реализации сети синхронной цифровой иерархии (SDH) для обеспечения и измерения QoS. Для каждого поставщика услуг это непростая задача удовлетворить спрос клиента. Сеть SDH развивалась, поскольку сеть PDH не поддерживает такие функции, как мультиплексирование более высокого порядка, обеспечивая лучшее качество обслуживания (QoS), топологии сети, отличные от линейных, и сложность с добавлением мультиплексирования с отбрасыванием и т.д. SDH может поддерживать QoS лучше, чем PDH. Конфигурация SDH выполняется для реализации, а проблемы проектирования анализируются для будущего решения. Измерение QoS выполняется для измерения производительности сети. Due to rapid advances in modern technology and the huge need for increased bandwidth, the use of modern facilities requires a more complex network topology to provide better quality of service (QoS). These requirements, in turn, imply high accuracy of design and perfection of synchronization methods. The aim of this study is to solve a way to overcome the above problem by implementing a synchronous digital hierarchy (SDH) network to provide and measure QoS. For each service provider, it is not an easy task to meet customer demand. The SDH network has evolved because the PDH network does not support features such as higher order multiplexing, providing better quality of service (QoS), network topologies other than linear, and complexity with the addition of drop multiplexing, etc. SDH can support QoS better than PDH. The configuration is performed for the SDH implementation as problems of design analyses for future decisions. The QoS measurement is performed to measure network performance.

scholarly journals A TWO-LEVEL APPROACH FOR THE CROWD-BASED COLLECTION OF VEHICLES FROM 3D POINT CLOUDS

2021 ◽  
Vol V-4-2021 ◽  
pp. 97-104
Author(s):  
V. Walter ◽  
M. Kölle ◽  
D. Collmar ◽  
Y. Zhang
Keyword(s):  
Point Cloud ◽  
Point Clouds ◽  
3D Point Cloud ◽  
3D Point Clouds ◽  
Bounding Box ◽  
Geometric Quality ◽  
Bounding Boxes ◽  
The Individual ◽  
Better Than

Abstract. In this article, we present a two-level approach for the crowd-based collection of vehicles from 3D point clouds. In the first level, the crowdworkers are asked to identify the coarse positions of vehicles in 2D rasterized shadings that were derived from the 3D point cloud. In order to increase the quality of the results, we utilize the wisdom of the crowd principle which says that averaging multiple estimates of a group of individuals provides an outcome that is often better than most of the underlying estimates or even better than the best estimate. For this, each crowd job is duplicated 10 times and the multiple results are integrated with a DBSCAN cluster algorithm. In the second level, we use the integrated results as pre-information for extracting small subsets of the 3D point cloud that are then presented to crowdworkers for approximating the included vehicle by means of a Minimum Bounding Box (MBB). Again, the crowd jobs are duplicated 10 times and an average bounding box is calculated from the individual bounding boxes. We will discuss the quality of the results of both steps and show that the wisdom of the crowd significantly improves the completeness as well as the geometric quality. With a tenfold acquisition, we have achieve a completeness of 93.3 percent and a geometric deviation of less than 1 m for 95 percent of the collected vehicles.

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