scholarly journals Improving CPT-InSAR Algorithm with Adaptive Coherent Distributed Pixels Selection

2021 ◽  
Vol 13 (23) ◽  
pp. 4784
Author(s):  
Longkai Dong ◽  
Chao Wang ◽  
Yixian Tang ◽  
Hong Zhang ◽  
Lu Xu
Keyword(s):  
Urban Areas ◽  
Surface Deformation ◽  
Spatial Scales ◽  
Ground Surface ◽  
Adaptive Method ◽  
Measuring Point ◽  
Deformation Parameters ◽  
Interferometric Phase ◽  
Phase Optimization

The Coherent Pixels Technique Interferometry Synthetic Aperture Radar (CPT-InSAR) method of inverting surface deformation parameters by using high-quality measuring points possesses the flaw inducing sparse measuring points in non-urban areas. In this paper, we propose the Adaptive Coherent Distributed Pixel InSAR (ACDP-InSAR) method, which is an adaptive method used to extract Distributed Scattering Pixel (DSP) based on statistically homogeneous pixel (SHP) cluster tests and improves the phase quality of DSP through phase optimization, which cooperates with Coherent Pixel (CP) for the retrieval of ground surface deformation parameters. For a region with sparse CPs, DSPs and its SHPs are detected by double-layer windows in two steps, i.e., multilook windows and spatial filtering windows, respectively. After counting the pixel number of maximum SHP cluster (MSHPC) in the multilook window based on the Anderson–Darling (AD) test and filtering out unsuitable pixels, the candidate DSPs are selected. For the filtering window, the SHPs of MSHPC’ pixels within the new window, which is different compared with multilook windows, were detected, and the SHPs of DSPs were obtained, which were used for coherent estimation. In phase-linking, the results of Eigen decomposition-based Maximum likelihood estimator of Interferometric phase (EMI) results are used as the initial values of the phase triangle algorithm (PTA) for the purpose of phase estimation (hereafter called as PTA-EMI). The DSPs and estimated phase are then combined with CPs in order to retrievesurface deformation parameters. The method was validated by two cases. The results show that the density of measuring points increased approximately 6–10 times compared with CPT-InSAR, and the quality of the interferometric phase significantly improved after phase optimization. It was demonstrated that the method is effective in increasing measuring point density and improving phase quality, which increases significantly the detectability of the low coherence region. Compared with the Distributed Scatterer InSAR (DS-InSAR) technique, ACDP-InSAR possesses faster processing speed at the cost of resolution loss, which is crucial for Earth surface movement monitoring at large spatial scales.

scholarly journals Generation of Persistent Scatterers in Non-Urban Areas: The Role of Microwave Scattering Parameters

Geosciences ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 269 ◽  
Author(s):  
Giovanni Nico ◽  
Sérgio Oliveira ◽  
Joao Catalão ◽  
José Zêzere
Keyword(s):  
Urban Areas ◽  
Ground Surface ◽  
Synthetic Aperture ◽  
Scattering Parameters ◽  
Microwave Scattering ◽  
Sparse Vegetation ◽  
Persistent Scatterers ◽  
Interferometric Phase ◽  
Interferometric Sar

In this work, we study the capability of the ground surface to generate Persistent Scatterers (PS) based on the lithology, slope and aspect angles. These properties affect the scattering behavior of the Synthetic Aperture Radar (SAR) signal, the interferometric phase stability and, as a consequence, the PS generation. Two-time series of interferometric SAR data acquired by two different SAR sensors in the C-band are processed to generate independent PS datasets. The region north of Lisbon, Portugal, characterized by sparse vegetation and lithology diversity, is chosen as study area. The PS frequency distribution is obtained in terms of lithology, slope and aspect angles. This relationship could be useful to estimate the expected PS density in landslide-prone areas, being lithology, slope and aspect angles important landslide predisposing factors.

scholarly journals Retrieval of Three-Dimensional Surface Deformation Using an Improved Differential SAR Tomography System

Electronics ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 174 ◽  
Author(s):  
Zhigui Wang ◽  
Mei Liu ◽  
Kunfeng Lv
Keyword(s):  
Synthetic Aperture Radar ◽  
Surface Deformation ◽  
Three Dimensional ◽  
Ground Surface ◽  
Real Data ◽  
Synthetic Aperture ◽  
The North ◽  
Deformation Parameters ◽  
Phase Signal ◽  
Aperture Radar

Conventional differential synthetic aperture radar tomography (D-TomoSAR) can only capture the scatterers’ one-dimensional (1-D) deformation information along the line of sight (LOS) of the synthetic aperture radar (SAR), which means that it cannot retrieve the three-dimensional (3-D) movements of the ground surface. To retrieve the 3-D deformation displacements, several methods have been proposed; the performance is limited due to the insufficient sensitivity for retrieving the North-South motion component. In this paper, an improved D-TomoSAR model is established by introducing the scatterers’ 3-D deformation parameters in slant range, azimuth, and elevation directions into the traditional D-TomoSAR model. The improved D-TomoSAR can be regarded as a multi-component two-dimensional (2-D) polynomial phase signal (PPS). Then, an effective algorithm is proposed to retrieve the 3-D deformation parameters of the ground surface by the 2-D product high-order ambiguity function (PHAF) with the relax (RELAX) algorithm. The estimation performance is investigated and compared with the traditional algorithm. Simulations and experimental results with semi-real data verify the effectiveness of the proposed signal model and algorithm.

scholarly journals Prediction of ground surface settlement induced by twin shield tunnellings in urban conditions

2021 ◽  
Vol 62 (2) ◽  
pp. 47-56
Author(s):  
Thai Ngoc Do ◽  
Truong Duc Nguyen ◽  
Keyword(s):  
Urban Areas ◽  
Surface Deformation ◽  
Ground Surface ◽  
Ground Subsidence ◽  
Analysis Model ◽  
Shield Tunneling ◽  
Construction Technique ◽  
Ground Deformations ◽  
Ground Surface Settlement ◽  
Surface Settlements

Tunneling in urban areas is growing in response to the increased needs for efficient transportation. Many urban tunnels are constructed in soft ground at shallow depths. Metro tunnels are usually constructed as twin-parallel tunnels and their adjacent constructions may lead to surface deformation, affecting the surface environment and the safety of the tunnels. Shield tunnelling is a commonly used as construction technique because it is very effective in reducing ground deformations and thus damage to urban infrastructure. The paper presents a 3D simulation of shield tunneling machines via the finite element code Abaqus and analysis model of ground surface settlements induced by a construction of twin-parallel tunnels. The results show that ground surface settlements induced by a construction of the left tunnel causes surface settlements of about 22÷24 mm and after the construction of both tunnels, it will cause ground subsidence has the greatest value of 33÷35 mm.

scholarly journals Localized Subsidence Zones in Gävle City Detected by Sentinel-1 PSI and Leveling Data

2020 ◽  
Vol 12 (16) ◽  
pp. 2629
Author(s):  
Nureldin A. A. Gido ◽  
Mohammad Bagherbandi ◽  
Faramarz Nilfouroushan
Keyword(s):  
Land Surface ◽  
Urban Areas ◽  
Surface Deformation ◽  
Subsurface Layer ◽  
Ground Surface ◽  
Surface Subsidence ◽  
Economic Consequences ◽  
Persistent Scatterer Interferometry ◽  
Persistent Scatterer ◽  
Spatio Temporal

Among different sets of constraints and hazards that have to be considered in the management of cities and land use, land surface subsidence is one of the important issues that can lead to many problems, and its economic consequences cannot be ignored. In this study, the ground surface deformation of Gävle city in Sweden is investigated using the Persistent Scatterer Interferometry (PSI) technique as well as analyzing the historical leveling data. The PSI technique is used to map the location of hazard zones and their ongoing subsidence rate. Two ascending and descending Sentinel-1 datasets, collected between January 2015 and May 2020, covering the Gävle city, were processed and analyzed. In addition, a long record of a leveling dataset, covering the period from 1974 to 2019, was used to detect the rate of subsidence in some locations which were not reported before. Our PSI analysis reveals that the center of Gävle is relatively stable with minor deformation ranged between −2 ± 0.5 mm/yr to +2 ± 0.5 mm/yr in vertical and east–west components. However, the land surface toward the northeast of the city is relatively subsiding with a higher annual rate of up to −6 ± 0.46 mm/yr. The comparison at sparse locations shows a close agreement between the subsidence rates obtained from precise leveling and PSI results. The regional quaternary deposits map was overlaid with PSI results and it shows the subsidence areas are mostly located in zones where the subsurface layer is marked by artificial fill materials. The knowledge of the spatio-temporal extents of land surface subsidence for undergoing urban areas can help to develop and establish models to mitigate hazards associated with such land settlement.

Spatial Autocorrelation in the Study of Neighbourhoods towards Smart Cities: Empirical Evidence from Kerman, Iran

2012 ◽  
Vol 9 (2) ◽  
pp. 1
Author(s):  
Asra Hosseini
Keyword(s):  
Spatial Autocorrelation ◽  
Urban Areas ◽  
Smart Cities ◽  
Moran’S I ◽  
Moran's I ◽  
Urban Planner ◽  
Universal Feature ◽  
Autocorrelation Method ◽  
Selection Of

From earliest cities to the present, spatial division into residential zones and neighbourhoods is the universal feature of urban areas. This study explored issue of measuring neighbourhoods through spatial autocorrelation method based on Moran's I index in respect of achieving to best neighbourhoods' model for forming cities smarter. The research carried out by selection of 35 neighbourhoods only within central part of traditional city of Kerman in Iran. The results illustrate, 75% of neighbourhoods' area in the inner city of Kerman had clustered pattern, and it shows reduction in Moran's index is associated with disproportional distribution of density and increasing in Moran's I and Z-score have monotonic relation with more dense areas and clustered pattern. It may be more efficient for urban planner to focus on spatial autocorrelation to foster neighbourhood cohesion rather than emphasis on suburban area. It is recommended characteristics of historic neighbourhoods can be successfully linked to redevelopment plans toward making city smarter, and also people's quality of life can be related to the way that neighbourhoods' patterns are defined. 

Quality indicator of the smart city transportation and logistics system

2020 ◽  
Vol 19 (11) ◽  
pp. 2116-2135
Author(s):  
G.V. Savin
Keyword(s):  
Intelligent Transportation Systems ◽  
Smart City ◽  
Urban Areas ◽  
Human Life ◽  
Life Quality ◽  
Intelligent Transportation ◽  
Transportation Systems ◽  
Logistics System ◽  
Organization And Management

Subject. The article considers functioning and development of process flows of transportation and logistics system of a smart city. Objectives. The study identifies factors and dependencies of the quality of human life on the organization and management of stream processes. Methods. I perform a comparative analysis of previous studies, taking into account the uniquely designed results, and the econometric analysis. Results. The study builds multiple regression models that are associated with stream processes, highlights interdependent indicators of temporary traffic and pollution that affect the indicator of life quality. However, the identified congestion indicator enables to predict the time spent in traffic jams per year for all participants of stream processes. Conclusions. The introduction of modern intelligent transportation systems as a component of the transportation and logistics system of a smart city does not fully solve the problems of congestion in cities at the current rate of urbanization and motorization. A viable solution is to develop cooperative and autonomous intelligent transportation systems based on the logistics approach. This will ensure control over congestion, the reduction of which will contribute to improving the life quality of people in urban areas.

The Determinants of Entrepreneurship Development in Spatial Systems

2017 ◽  
Vol 13 ◽  
pp. 8-24
Author(s):  
Zbigniew Zioło
Keyword(s):  
Spatial Scales ◽  
Institutional Barriers ◽  
Entrepreneurship Development ◽  
Continental Scale ◽  
Spatial Systems ◽  
Business Conditions ◽  
Mutual Relations ◽  
Growth Shape ◽  
Strategic Goal

The processes of technological  progress create new opportunities for economic, social and cultural growth, shape new relations between economic  entities and their environment,  and influence changes in the determinants  of entrepreneurship development.  These processes vary significantly in certain geographic locations, characterised by an enormous  diversity of natural, social, economic and cultural structures. As a consequence, this creates different opportunities  and different conditions for the development of entrepreneurship in certain spatial scales, from the continental scale, through national and regional to local scales. The article presents complex conditions  for the development of entrepreneurship, highlights its limitations resulting from institutional  barriers, and the importance of knowing the mechanisms of mutual relations between spatial systems and the influence of control instruments. The quality of central and local government authorities is of particular significance here, which do not always properly use the mechanisms of rational business support. A serious barrier to the development of entrepreneurship is the low quality of social capital, manifested in a lack of trust in institutional authorities and reluctance to engage in entrepreneurship and business development. The conclusions point out that further research should be developed that will take into account changing business conditions, with a defined strategic goal of raising the quality and standard of living, international competitiveness of the country and products in different market categories.

Classroom Management

2016 ◽  
Vol 1 (1) ◽  
pp. 201
Author(s):  
Elida Kurti
Keyword(s):  
Classroom Management ◽  
General Education ◽  
Urban Areas ◽  
Teaching And Learning ◽  
Educational Institutions ◽  
Important Place ◽  
Rural And Urban Areas ◽  
Rural And Urban ◽  
Intellectual Level

This paper aims to reflect an effort to identify the problems associated with the educational learning process, as well as its function to express some inherent considerations to the most effective forms of the classroom management. Mentioned in this discussion are ways of management for various categories of students, not only from an intellectual level, but also by their behavior. Also, in the elaboration of this theme I was considering that in addition to other development directions of the country, an important place is occupied by the education of the younger generation in our school environments and especially in adopting the methods of teaching and learning management with a view to enable this generation to be competitive in the European labor market. This, of course, can be achieved by giving this generation the best values of behavior, cultural level, professional level and ethics one of an European family which we belong to, not just geographically. On such foundations, we have tried to develop this study, always improving the reality of the prolonged transition in the field of children’s education. Likewise, we have considered the factors that have left their mark on the structure, cultural level and general education level of children, such as high demographic turnover associated with migration from rural and urban areas, in the capacity of our educational institutions to cope with new situations etc. In the conclusions of this study is shown that there is required a substantial reform even in the pro-university educational system to ensure a significant improvement in the behavior of children, relations between them and the sound quality of their preparation. Used literature for this purpose has not been lacking, due to the fact that such problems are usually treated by different scholars. Likewise, we found it appropriate to use the ideas and issues discussed by the foreign literature that deals directly with classroom management problems. All the following treatise is intended to reflect the way of an effective classroom management.

Deterioration in the Water Quality of Groundwater in Some Municipal Water Extraction Plants in Finland

1979 ◽  
Vol 10 (2-3) ◽  
pp. 171-190
Author(s):  
Pertti Lahermo ◽  
Jouko Parviainen
Keyword(s):  
Water Quality ◽  
Urban Areas ◽  
Water Extraction ◽  
Groundwater Extraction ◽  
Dissolved Solids ◽  
Municipal Water ◽  
The 1960S

In this study the changes in the quality of groundwater are described on the basis of material collected at some groundwater extraction plants situated mainly in urban areas. The causes of the marked increase in the content of dissolved solids are evaluated from the 1960s onwards.

Urban Transport

2018 ◽  
Author(s):  
José van
Keyword(s):  
Urban Areas ◽  
Urban Transport ◽  
Transport Sector ◽  
Public And Private ◽  
Transport Services ◽  
Ride Sharing ◽  
The World ◽  
Private And Public ◽  
Selection Mechanisms

Platformization affects the entire urban transport sector, effectively blurring the division between private and public transport modalities; existing public–private arrangements have started to shift as a result. This chapter analyzes and discusses the emergence of a platform ecology for urban transport, focusing on two central public values: the quality of urban transport and the organization of labor and workers’ rights. Using the prism of platform mechanisms, it analyzes how the sector of urban transport is changing societal organization in various urban areas across the world. Datafication has allowed numerous new actors to offer their bike-, car-, or ride-sharing services online; selection mechanisms help match old and new complementors with passengers. Similarly, new connective platforms are emerging, most prominently transport network companies such as Uber and Lyft that offer public and private transport options, as well as new platforms offering integrated transport services, often referred to as “mobility as a service.”

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