scholarly journals Polygonal terrains on Mars

Finisterra ◽  
2012 ◽  
Vol 44 (87) ◽  
Author(s):  
José Saraiva ◽  
Lourenço Bandeira ◽  
Joana Antunes ◽  
Pedro Pina ◽  
Teresa Barata
Keyword(s):  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Temporal Evolution ◽  
Small Scale ◽  
Automated Identification ◽  
Research Project ◽  
Water Ice ◽  
Full Characterization

The presence of water ice on mars is well established. Some features on the planet point to the occurrence of processes similar to those that take place in periglacial areas of Earth. one of the clues for this is the existence of small-scale polygonal terrains. In this paper, we present a methodology that aims at the automated identification of polygonal patterns on high-spatial resolution images of the surface of mars. In the context of the research project TERpolI, this step will be complemented with a full characterization, in both geometric and topological terms, of the networks detected. In this manner, we hope to collect data that will lead to a better understanding of the conditions of formation of the polygons, and of their temporal evolution; namely, we intend to identify different groups of polygons and to compare them with terrestrial examples.

scholarly journals Precipitation Atlas for Germany (GePrA)

Atmosphere ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 737
Author(s):  
Christopher Jung ◽  
Dirk Schindler
Keyword(s):  
Spatial Resolution ◽  
Large Scale ◽  
High Spatial Resolution ◽  
Spline Interpolation ◽  
Absolute Error ◽  
Coefficient Of Determination ◽  
Small Scale ◽  
Monthly Precipitation ◽  
New Approach ◽  
Very High Spatial Resolution

A new approach for modeling daily precipitation (RR) at very high spatial resolution (25 m × 25 m) was introduced. It was used to develop the Precipitation Atlas for Germany (GePrA). GePrA is based on 2357 RR time series measured in the period 1981–2018. It provides monthly percentiles (p) of the large-scale RR patterns which were mapped by a thin plate spline interpolation (TPS). A least-squares boosting (LSBoost) approach and orographic predictor variables (PV) were applied to integrate the small-scale precipitation variability in GePrA. Then, a Weibull distribution (Wei) was fitted to RRp. It was found that the mean monthly sum of RR ( R R ¯ s u m ) is highest in July (84 mm) and lowest in April (49 mm). A great dependency of RR on the elevation (ε) was found and quantified. Model validation at 425 stations showed a mean coefficient of determination (R2) of 0.80 and a mean absolute error (MAE) of less than 10 mm in all months. The high spatial resolution, including the effects of the local orography, make GePrA a valuable tool for various applications. Since GePrA does not only describe R R ¯ s u m , but also the entire monthly precipitation distributions, the results of this study enable the seasonal differentiation between dry and wet period at small scales.

scholarly journals Resolving Io’s Volcanoes from a Mutual Event Observation at the Large Binocular Telescope

2021 ◽  
Vol 2 (6) ◽  
pp. 227
Author(s):  
Katherine de Kleer ◽  
Michael Skrutskie ◽  
Jarron Leisenring ◽  
Ashley G. Davies ◽  
Al Conrad ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Temporal Evolution ◽  
Light Curves ◽  
Lava Flows ◽  
Volcanic Center ◽  
Active Volcanism ◽  
Geological Processes ◽  
Areal Coverage

Abstract Unraveling the geological processes ongoing at Io’s numerous sites of active volcanism requires high spatial resolution to, for example, measure the areal coverage of lava flows or identify the presence of multiple emitting regions within a single volcanic center. In de Kleer et al. (2017) we described observations with the Large Binocular Telescope during an occultation of Io by Europa at ∼6:17 UT on 2015 March 8 and presented a map of the temperature distribution within Loki Patera derived from these data. Here we present emission maps of three other volcanic centers derived from the same observation: Pillan Patera, Kurdalagon Patera, and the vicinity of Ulgen Patera/PV59/N Lerna Regio. The emission is localized by the light curves and resolved into multiple distinct emitting regions in two of the cases. Both Pillan and Kurdalagon Paterae had undergone eruptions in the months prior to our observations, and the location and intensity of the emission are interpreted in the context of the temporal evolution of these eruptions observed from other facilities. The emission from Kurdalagon Patera is resolved into two distinct emitting regions separated by only a few degrees in latitude that were unresolved by Keck observations from the same month.

scholarly journals Investigation of Large Scale Motions in Zero and Adverse Pressure Gradient Turbulent Boundary Layers Using High-Spatial-Resolution PIV

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Daniel Jovic ◽  
Muhammad Shehzad ◽  
Bihai Sun ◽  
Christophe Cuvier ◽  
Christian Willert ◽  
...  
Keyword(s):  
Pressure Gradient ◽  
Spatial Resolution ◽  
Large Scale ◽  
High Spatial Resolution ◽  
Adverse Pressure Gradient ◽  
Velocity Fields ◽  
Small Scale ◽  
Measured Velocity ◽  
Image Velocimetry ◽  
High Reynolds

Particle image velocimetry (PIV) has been used to capture the high-spatial-resolution (HSR) two-component, two-dimensional (2C-2D) velocity fields of a zero-pressure-gradient (ZPG) turbulent boundary layer (TBL) and of an adverse-pressure-gradient (APG) TBL. Proper Orthogonal Decomposition (POD) is performed on the measured velocity fields to characterize the velocity fields as large or small scale motions (LSMs or SSMs), with further characterisation of the LSMs into high and low momentum events. This paper reports the findings of the PIV experiment and the subsequent analysis of the high Reynolds number ZPG and APG TBLs

scholarly journals Google Earth Engine Open-Source Code for Land Surface Temperature Estimation from the Landsat Series

2020 ◽  
Vol 12 (9) ◽  
pp. 1471 ◽  
Author(s):  
Sofia L. Ermida ◽  
Patrícia Soares ◽  
Vasco Mantas ◽  
Frank-M. Göttsche ◽  
Isabel F. Trigo
Keyword(s):  
Surface Temperature ◽  
Spatial Resolution ◽  
Land Surface Temperature ◽  
Land Surface ◽  
High Spatial Resolution ◽  
Urban Climate ◽  
Google Earth ◽  
Small Scale ◽  
Temperature Estimation ◽  
Google Earth Engine

Land Surface Temperature (LST) is increasingly important for various studies assessing land surface conditions, e.g., studies of urban climate, evapotranspiration, and vegetation stress. The Landsat series of satellites have the potential to provide LST estimates at a high spatial resolution, which is particularly appropriate for local or small-scale studies. Numerous studies have proposed LST retrieval algorithms for the Landsat series, and some datasets are available online. However, those datasets generally require the users to be able to handle large volumes of data. Google Earth Engine (GEE) is an online platform created to allow remote sensing users to easily perform big data analyses without increasing the demand for local computing resources. However, high spatial resolution LST datasets are currently not available in GEE. Here we provide a code repository that allows computing LSTs from Landsat 4, 5, 7, and 8 within GEE. The code may be used freely by users for computing Landsat LST as part of any analysis within GEE.

scholarly journals In-situ high spatial resolution LA-MC-ICPMS 230 Th/U dating enables detection of small-scale age inversions in speleothems

2017 ◽  
Vol 2 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Yiming Lin ◽  
Klaus Peter Jochum ◽  
Denis Scholz ◽  
Dirk L. Hoffmann ◽  
Brigitte Stoll ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Small Scale

scholarly journals Ground-Based Observations of Type III Bursts

1974 ◽  
Vol 57 ◽  
pp. 161-181 ◽  
Author(s):  
R. T. Stewart
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Spatial Resolution ◽  
Weak Magnetic Field ◽  
High Spatial Resolution ◽  
Small Scale ◽  
Type Iii ◽  
The Past ◽  
Scale Size

Observations over the past 20 yrs or so are reviewed, with emphasis on recent high spatial resolution observations. The results lend support to earlier ideas on the propagation of type III electron streams through coronal regions of weak magnetic field strength but have not as yet settled the question whether the electrons propagate along the axes of coronal streamers. Several important burst properties appear to be significantly affected by ray scattering on small-scale size density irregularities in the corona.

scholarly journals Super-Resolution of Sentinel-2 Imagery Using Generative Adversarial Networks

2020 ◽  
Vol 12 (15) ◽  
pp. 2424
Author(s):  
Luis Salgueiro Romero ◽  
Javier Marcello ◽  
Verónica Vilaplana
Keyword(s):  
Remote Sensing ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Super Resolution ◽  
Generative Adversarial Networks ◽  
Small Scale ◽  
Remote Sensing Images ◽  
Very High Spatial Resolution ◽  
Very High ◽  
Sentinel 2

Sentinel-2 satellites provide multi-spectral optical remote sensing images with four bands at 10 m of spatial resolution. These images, due to the open data distribution policy, are becoming an important resource for several applications. However, for small scale studies, the spatial detail of these images might not be sufficient. On the other hand, WorldView commercial satellites offer multi-spectral images with a very high spatial resolution, typically less than 2 m, but their use can be impractical for large areas or multi-temporal analysis due to their high cost. To exploit the free availability of Sentinel imagery, it is worth considering deep learning techniques for single-image super-resolution tasks, allowing the spatial enhancement of low-resolution (LR) images by recovering high-frequency details to produce high-resolution (HR) super-resolved images. In this work, we implement and train a model based on the Enhanced Super-Resolution Generative Adversarial Network (ESRGAN) with pairs of WorldView-Sentinel images to generate a super-resolved multispectral Sentinel-2 output with a scaling factor of 5. Our model, named RS-ESRGAN, removes the upsampling layers of the network to make it feasible to train with co-registered remote sensing images. Results obtained outperform state-of-the-art models using standard metrics like PSNR, SSIM, ERGAS, SAM and CC. Moreover, qualitative visual analysis shows spatial improvements as well as the preservation of the spectral information, allowing the super-resolved Sentinel-2 imagery to be used in studies requiring very high spatial resolution.

scholarly journals High spatial resolution monitoring of the activity of BA supergiant winds

2010 ◽  
Vol 6 (S272) ◽  
pp. 342-347
Author(s):  
Olivier Chesneau ◽  
Luc Dessart ◽  
Andreas Kaufer ◽  
Denis Mourard ◽  
Otmar Stahl ◽  
...  
Keyword(s):  
Spatial Structure ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Temporal Evolution ◽  
Optical Interferometry ◽  
Wind Activity ◽  
Better Than

AbstractThere are currently two optical interferometry recombiners that can provide spectral resolutions better than 10000, AMBER/VLTI operating in the H-K bands, and VEGA/CHARA, recently commissioned, operating in the visible. These instruments are well suited to study the wind activity of the brightest AB supergiants in our vicinity, in lines such as Hα or Brγ. We present here the first observations of this kind, performed on Rigel (B8Ia) and Deneb (A2Ia). Rigel was monitored by AMBER in two campaigns, in 2006-2007 and 2009-2010, and observed in 2009 by VEGA; whereas Deneb was monitored in 2008-2009 by VEGA. The extension of the Hα and Brγ line forming regions were accurately measured and compared with CMFGEN models of both stars. Moreover, clear signs of activity were observed in the differential visibility and phases. These pioneer observations are still limited, but show the path for a better understanding of the spatial structure and temporal evolution of localized ejections using optical interferometry.

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