Very high resolution observations of compact sources in the direction of supernova remnants - G74.87 + 1.22

1984 ◽  
Vol 286 ◽  
pp. 284 ◽  
Author(s):  
B. J. Geldzahler ◽  
D. B. Shaffer ◽  
H. Kuhr
Keyword(s):  
High Resolution ◽  
Supernova Remnants ◽  
Compact Sources ◽  
Very High

scholarly journals Two GeV-TeV Supernova Remnants without Associated Neutral and Molecular Clouds

2013 ◽  
Vol 9 (S297) ◽  
pp. 229-231
Author(s):  
W. Tian ◽  
D. Leahy ◽  
H. Zhu ◽  
H. Su
Keyword(s):  
Star Formation ◽  
High Velocity ◽  
Molecular Clouds ◽  
Supernova Remnants ◽  
Gamma Ray ◽  
Star Formation Region ◽  
Formation Region ◽  
High Gamma ◽  
Compact Sources ◽  
Very High

AbstractTeV gamma ray emissions have been detected at the directions of supernova remnants (SNRs) W51C and Tycho SNR. We analyze the Hi absorption spectra towards W51C, Tycho SNR and their nearby compact sources. We conclude that W51C is at a distance of about 4.3 kpc and Tycho SNR has a distance of 2.5 ~ 3.0 kpc. Our study detects high-velocity Hi clouds which coincide with star formation region W51B, but finds that the clouds are behind W51B which argues against previous claims that W51C has shocked the high velocity Hi clouds. We argue that Tycho SNR is naked Ia SNR (lack of evidence of interacting with adjacent neutral and molecular cloud). This gives two examples that the very high gamma ray emission from SNRs does not likely originate from SNR-cloud interaction.

Very High Resolution Analysis of the Dynamics of a Coronal Plasmoid

1994 ◽  
Vol 144 ◽  
pp. 593-596
Author(s):  
O. Bouchard ◽  
S. Koutchmy ◽  
L. November ◽  
J.-C. Vial ◽  
J. B. Zirker
Keyword(s):  
High Resolution ◽  
Solar Eclipse ◽  
Total Solar Eclipse ◽  
Field Of View ◽  
Small Field ◽  
High Resolution Analysis ◽  
Ccd Observations ◽  
Resolution Analysis ◽  
Very High ◽  
Small Field Of View

AbstractWe present the results of the analysis of a movie taken over a small field of view in the intermediate corona at a spatial resolution of 0.5“, a temporal resolution of 1 s and a spectral passband of 7 nm. These CCD observations were made at the prime focus of the 3.6 m aperture CFHT telescope during the 1991 total solar eclipse.

Three-dimensional fault geometry and kinematics of the 2008 M 7.1 Yutian earthquake revealed by very-high resolution satellite stereo imagery

2019 ◽  
Vol 232 ◽  
pp. 111300
Author(s):  
Xiaogang Song ◽  
Nana Han ◽  
Xinjian Shan ◽  
Chisheng Wang ◽  
Yingfeng Zhang ◽  
...  
Keyword(s):  
High Resolution ◽  
Three Dimensional ◽  
Fault Geometry ◽  
Stereo Imagery ◽  
Very High ◽  
Geometry And Kinematics

scholarly journals Object Oriented Classification for Mapping Mixed and Pure Forest Stands Using Very-High Resolution Imagery

2021 ◽  
Vol 13 (13) ◽  
pp. 2508
Author(s):  
Loredana Oreti ◽  
Diego Giuliarelli ◽  
Antonio Tomao ◽  
Anna Barbati
Keyword(s):  
High Resolution ◽  
Spatial Scales ◽  
Parametric Method ◽  
Mixed Forest ◽  
Mixed Stands ◽  
Mapping Unit ◽  
Mixed Forests ◽  
High Resolution Imagery ◽  
Very High Resolution Imagery ◽  
Very High

The importance of mixed forests is increasingly recognized on a scientific level, due to their greater productivity and efficiency in resource use, compared to pure stands. However, a reliable quantification of the actual spatial extent of mixed stands on a fine spatial scale is still lacking. Indeed, classification and mapping of mixed populations, especially with semi-automatic procedures, has been a challenging issue up to date. The main objective of this study is to evaluate the potential of Object-Based Image Analysis (OBIA) and Very-High-Resolution imagery (VHR) to detect and map mixed forests of broadleaves and coniferous trees with a Minimum Mapping Unit (MMU) of 500 m2. This study evaluates segmentation-based classification paired with non-parametric method K- nearest-neighbors (K-NN), trained with a dataset independent from the validation one. The forest area mapped as mixed forest canopies in the study area amounts to 11%, with an overall accuracy being equal to 85% and K of 0.78. Better levels of user and producer accuracies (85–93%) are reached in conifer and broadleaved dominated stands. The study findings demonstrate that the very high resolution images (0.20 m of spatial resolutions) can be reliably used to detect the fine-grained pattern of rare mixed forests, thus supporting the monitoring and management of forest resources also on fine spatial scales.

An Approach for Building Rooftop Border Extraction from Very High-Resolution Satellite Images

2021 ◽  
pp. 1-11
Author(s):  
Yasser Mostafa ◽  
Mahmoud Nokrashy O. Ali ◽  
Faten Mostafa ◽  
Mohamed Yousef
Keyword(s):  
High Resolution ◽  
Satellite Images ◽  
High Resolution Satellite Images ◽  
Very High
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