scholarly journals MAPPING AND MONITORING GROUND INSTABILITIES WITH SENTINEL-1 DATA: THE EXPERIENCE OF SERNAGEOMIN

Author(s):  
P. Olea ◽  
O. Monserrat ◽  
C. Sierralta ◽  
A. Barra ◽  
L. Bono ◽  
...  

Abstract. The application of Satellite Differential SAR interferometry (DInSAR) has become a reliable solution as a tool for mapping and monitoring geohazards. Few years ago, the main applications of these techniques were devoted to science. However, nowadays, the easy access to SAR imagery and the maturity of the techniques to exploit these type of data has widened the user’s spectrum from only scientists to professional and decision makers. The advent of Sentinel-1 satellites has significantly contributed to this achievement. In particular, in the field of geohazard risk management, Sentinel-1 has solved one of the main constraining factors that hindered the operational use of interferometric techniques in the past: the lack of systematic acquisition plans. In this context, Sentinel-1 assures worldwide coverage with short temporal baselines (6 to 24 days). This has supposed a definitive step towards the implementation of DInSAR based techniques to support decision makers against geohazards. In this work, we show the first experiences of the remote sensing unit of the Geological and Mining Survey of Chile (Sernageomin) with Sentinel-1 data. Three different case studies in different areas of the Chilean territory are presented. The examples illustrate how DInSAR based techniques can provide different levels of information about geohazard activity in different environments.

2021 ◽  
Vol 13 (7) ◽  
pp. 3923
Author(s):  
Anton Berwald ◽  
Gergana Dimitrova ◽  
Thijs Feenstra ◽  
Joop Onnekink ◽  
Harm Peters ◽  
...  

The increased diversity and complexity of plastics used in modern devices, such as electrical and electronic equipment (EEE), can have negative impacts on their recyclability. Today, the main economic driver for waste electrical and electronic equipment (WEEE) recycling stems from metal recovery. WEEE plastics recycling, on the other hand, still represents a major challenge. Strategies like design ‘for’, but also the much younger concept of design ‘from’ recycling play a key role in closing the material loops within a circular economy. While these strategies are usually analysed separately, this brief report harmonises them in comprehensive Design for Circularity guidelines, established in a multi-stakeholder collaboration with industry leaders from the entire WEEE value chain. The guidelines were developed at the product and part levels. They are divided in five categories: (1) avoidance of hazardous substances; (2) enabling easy access and removal of hazardous or polluting parts; (3) use of recyclable materials; (4) use of material combinations and connections allowing easy liberation; (5) use of recycled materials. These guidelines are the first harmonised set to be released for the EEE industry. They can readily serve decision-makers from different levels, including product designers and manufacturers as well as policymakers.


Author(s):  
C. Dou ◽  
H. Guo ◽  
C. Han ◽  
X. Yue ◽  
Y. Zhao

Short temporal baseline and multiple ground deformation information can be derived from the airborne differential synthetic aperture radar Interforemetry (D-InSAR). However, affected by the turbulence of the air, the aircraft would deviate from the designed flight path with high frequent vibrations and changes both in the flight trajectory and attitude. Restricted by the accuracy of the position and orientation system (POS), these high frequent deviations can not be accurately reported, which would pose great challenges in motion compensation and interferometric process. Thus, these challenges constrain its wider applications. The objective of this paper is to investigate the accurate estimation and compensation of the residual motion errors in the airborne SAR imagery and time-varying baseline errors between the diffirent data acquirations, furthermore, to explore the integration data processing theory for the airborne D-InSAR system, and thus help to accomplish the correct derivation of the ground deformation by using the airborne D-InSAR measurements.


1968 ◽  
Vol 62 (2) ◽  
pp. 476-480 ◽  
Author(s):  
Bruce M. Russett

In suggesting a basis for operational indices of the concentration of power Steven Brams' creative article “Measuring the Concentration of Power in Political Systems” (see pp. 461–475) has performed an important service to the discipline in opening up a neglected area. It is very surprising that despite all the past efforts to devise summary measures of power bases (e.g., income or military strength) so little effort has gone into summary indices for rigorously gauging their dispersion or the absence of dispersion. Having acknowledged Brams' piece as an extremely valuable stimulus for further thought, I would like now to exercise a scientific prerogative to propose a variation in the approach that should, for some theoretical purposes, prove even more useful. As Brams notes appropriately, it is indeed true that the best index “for any particular study will depend on the nature and purposes of the study.”All the versions of Brams' PC index are directed toward measuring the collective exercise of influence between different levels of decision-makers. This approach reflects an essentially deterministic point of view: the influence from any level on a mutual influence set or sets is determined by the exercise of influence on only one of its members. For example, if a has power over b, and b is in a mutual influence set with c, then c's actions vis-à-vis b are completely determined by a. As far as the PC index is concerned, this is no different from the case of a's directly influencing b and directly influencing c when b and c are not in an influence relationship. But if one takes a probabilistic viewpoint of indeterminacy, of a's predominance but less than complete control over b and c when they are in a mutual influence relationship, the relations among units at a subordinate level become interesting.


2019 ◽  
Vol 11 (4) ◽  
pp. 412 ◽  
Author(s):  
Fabrizio Lombardini ◽  
Francesco Cai

In synthetic aperture radar (SAR) remote sensing, Differential Tomography (Diff-Tomo) is developing as a powerful crossing of the mature Differential SAR Interferometry and the emerged 3D SAR Tomography. Diff-Tomo produces advanced 4D (3D+Time) SAR imaging capabilities, extensively applied to urban deformation monitoring. More recently, it has been shown that, through Diff-Tomo, identifying temporal spectra of multiple height-distributed decorrelating scatterers, the important decorrelation-robust forest Tomography functionality is possible. To loosen application constraints of the related main experimented full model-based processing, and develop other functionalities, this work presents an adaptive, just semi-parametric, generalized-Capon Diff-Tomo method, first conceived at University of Pisa in 2013, for joint extraction of height and dynamical information of natural distributed (volumetric) scatterers, with its formalization and a series of insights. Particular reference is given to the important functionality of the separation of different decorrelation mechanisms in forest layers. Representative simulated and P-band forest data sample results are also shown. The new Diff-Tomo method is getting a flexible and rich decorrelation-robust Tomography functionality, and is able to profile height-varying temporal decorrelation, for significantly distributed scatterers.


Urban Science ◽  
2020 ◽  
Vol 4 (4) ◽  
pp. 70
Author(s):  
Till Koglin ◽  
Lucas Glasare

This paper evaluates the history and cycling accessibility of Nova, a shopping centre established in Lund, Sweden, in 2002. The current situation was also analysed through observation and a literature review. Moreover, the study conducted a closer analysis of the history and role of the municipality based on further literature study and interviews with officials. The conclusion of the analysis indicates poor and unsafe bikeways caused by conflicts of interest between politicians, officials, landowners and the general public. It also depicts a situation in which the municipality’s master plan has been ignored, and, in contrast to the local goals, cycling accessibility at Nova has seen no significant improvement since the shopping centre was first established. The reasons for this, arguably, are a relatively low budget for bikeway improvements in the municipality, as well as a situation in which decision-makers have stopped approaching the subject, as a result of the long and often boisterous conflicts it has created in the past. Lastly, it must be noted that it is easy to regard the whole process of Nova, from its establishment to the current situation, as being symptomatic of the power structures between drivers and cyclists that still affect decision-makers at all levels.


2021 ◽  
Vol 11 (15) ◽  
pp. 6923
Author(s):  
Rui Zhang ◽  
Zhanzhong Tang ◽  
Dong Luo ◽  
Hongxia Luo ◽  
Shucheng You ◽  
...  

The use of remote sensing technology to monitor farmland is currently the mainstream method for crop research. However, in cloudy and misty regions, the use of optical remote sensing image is limited. Synthetic aperture radar (SAR) technology has many advantages, including high resolution, multi-mode, and multi-polarization. Moreover, it can penetrate clouds and mists, can be used for all-weather and all-time Earth observation, and is sensitive to the shape of ground objects. Therefore, it is widely used in agricultural monitoring. In this study, the polarization backscattering coefficient on time-series SAR images during the rice-growing period was analyzed. The rice identification results and accuracy of InSAR technology were compared with those of three schemes (single-time-phase SAR, multi-time-phase SAR, and combination of multi-time-phase SAR and InSAR). Results show that VV and VH polarization coherence coefficients can well distinguish artificial buildings. In particular, VV polarization coherence coefficients can well distinguish rice from water and vegetation in August and September, whereas VH polarization coherence coefficients can well distinguish rice from water and vegetation in August and October. The rice identification accuracy of single-time series Sentinel-1 SAR image (78%) is lower than that of multi-time series SAR image combined with InSAR technology (81%). In this study, Guanghan City, a cloudy region, was used as the study site, and a good verification result was obtained.


Universe ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 169
Author(s):  
Cristina Lazzeroni ◽  
Sandra Malvezzi ◽  
Andrea Quadri

The rapid changes in science and technology witnessed in recent decades have significantly contributed to the arousal of the awareness by decision-makers and the public as a whole of the need to strengthen the connection between outreach activities of universities and research institutes and the activities of educational institutions, with a central role played by schools. While the relevance of the problem is nowadays unquestioned, no unique and fully satisfactory solution has been identified. In the present paper we would like to contribute to the discussion on the subject by reporting on an ongoing project aimed to teach Particle Physics in primary schools. We will start from the past and currently planned activities in this project in order to establish a broader framework to describe the conditions for the fruitful interplay between researchers and teachers. We will also emphasize some aspects related to the dissemination of outreach materials by research institutions, in order to promote the access and distribution of scientific information in a way suited to the different age of the target students.


2021 ◽  
Vol 13 (13) ◽  
pp. 2570
Author(s):  
Teng Li ◽  
Bozhong Zhu ◽  
Fei Cao ◽  
Hao Sun ◽  
Xianqiang He ◽  
...  

Based on characteristics analysis about remote sensing reflectance, the Secchi Disk Depth (SDD) in the Qiandao Lake was predicted from the Landsat8/OLI data, and its changing rates on a pixel-by-pixel scale were obtained from satellite remote sensing for the first time. Using 114 matchups data pairs during 2013–2019, the SDD satellite algorithms suitable for the Qiandao Lake were obtained through both the linear regression and machine learning (Support Vector Machine) methods, with remote sensing reflectance (Rrs) at different OLI bands and the ratio of Rrs (Band3) to Rrs (Band2) as model input parameters. Compared with field observations, the mean absolute relative difference and root mean squared error of satellite-derived SDD were within 20% and 1.3 m, respectively. Satellite-derived results revealed that SDD in the Qiandao Lake was high in boreal spring and winter, and reached the lowest in boreal summer, with the annual mean value of about 5 m. Spatially, high SDD was mainly concentrated in the southeast lake area (up to 13 m) close to the dam. The edge and runoff area of the lake were less transparent, with an SDD of less than 4 m. In the past decade (2013–2020), 5.32% of Qiandao Lake witnessed significant (p < 0.05) transparency change: 4.42% raised with a rate of about 0.11 m/year and 0.9% varied with a rate of about −0.09 m/year. Besides, the findings presented here suggested that heavy rainfall would have a continuous impact on the Qiandao Lake SDD. Our research could promote the applications of land observation satellites (such as the Landsat series) in water environment monitoring in inland reservoirs.


2021 ◽  
Vol 13 (2) ◽  
pp. 292
Author(s):  
Megan Seeley ◽  
Gregory P. Asner

As humans continue to alter Earth systems, conservationists look to remote sensing to monitor, inventory, and understand ecosystems and ecosystem processes at large spatial scales. Multispectral remote sensing data are commonly integrated into conservation decision-making frameworks, yet imaging spectroscopy, or hyperspectral remote sensing, is underutilized in conservation. The high spectral resolution of imaging spectrometers captures the chemistry of Earth surfaces, whereas multispectral satellites indirectly represent such surfaces through band ratios. Here, we present case studies wherein imaging spectroscopy was used to inform and improve conservation decision-making and discuss potential future applications. These case studies include a broad array of conservation areas, including forest, dryland, and marine ecosystems, as well as urban applications and methane monitoring. Imaging spectroscopy technology is rapidly developing, especially with regard to satellite-based spectrometers. Improving on and expanding existing applications of imaging spectroscopy to conservation, developing imaging spectroscopy data products for use by other researchers and decision-makers, and pioneering novel uses of imaging spectroscopy will greatly expand the toolset for conservation decision-makers.


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