Elevation and Deformation Extraction from TomoSAR

3D SAR tomography (TomoSAR) and 4D SAR differential tomography (Diff-TomoSAR) exploit multi-baseline SAR data stacks to provide an essential innovation of SAR Interferometry for many applications, sensing complex scenes with multiple scatterers mapped into the same SAR pixel cell. However, these are still influenced by DEM uncertainty, temporal decorrelation, orbital, tropospheric and ionospheric phase distortion and height blurring. In this thesis, these techniques are explored. As part of this exploration, the systematic procedures for DEM generation, DEM quality assessment, DEM quality improvement and DEM applications are first studied. Besides, this thesis focuses on the whole cycle of systematic methods for 3D & 4D TomoSAR imaging for height and deformation retrieval, from the problem formation phase, through the development of methods to testing on real SAR data. After DEM generation introduction from spaceborne bistatic InSAR (TanDEM-X) and airborne photogrammetry (Bluesky), a new DEM co-registration method with line feature validation (river network line, ridgeline, valley line, crater boundary feature and so on) is developed and demonstrated to assist the study of a wide area DEM data quality. This DEM co-registration method aligns two DEMs irrespective of the linear distortion model, which improves the quality of DEM vertical comparison accuracy significantly and is suitable and helpful for DEM quality assessment. A systematic TomoSAR algorithm and method have been established, tested, analysed and demonstrated for various applications (urban buildings, bridges, dams) to achieve better 3D & 4D tomographic SAR imaging results. These include applying Cosmo-Skymed X band single-polarisation data over the Zipingpu dam, Dujiangyan, Sichuan, China, to map topography; and using ALOS L band data in the San Francisco Bay region to map urban building and bridge. A new ionospheric correction method based on the tile method employing IGS TEC data, a split-spectrum and an ionospheric model via least squares are developed to correct ionospheric distortion to improve the accuracy of 3D & 4D tomographic SAR imaging. Meanwhile, a pixel by pixel orbit baseline estimation method is developed to address the research gaps of baseline estimation for 3D & 4D spaceborne SAR tomography imaging. Moreover, a SAR tomography imaging algorithm and a differential tomography four-dimensional SAR imaging algorithm based on compressive sensing, SAR interferometry phase (InSAR) calibration reference to DEM with DEM error correction, a new phase error calibration and compensation algorithm, based on PS, SVD, PGA, weighted least squares and minimum entropy, are developed to obtain accurate 3D & 4D tomographic SAR imaging results. The new baseline estimation method and consequent TomoSAR processing results showed that an accurate baseline estimation is essential to build up the TomoSAR model. After baseline estimation, phase calibration experiments (via FFT and Capon method) indicate that a phase calibration step is indispensable for TomoSAR imaging, which eventually influences the inversion results. A super-resolution reconstruction CS based study demonstrates X band data with the CS method does not fit for forest reconstruction but works for reconstruction of large civil engineering structures such as dams and urban buildings. Meanwhile, the L band data with FFT, Capon and the CS method are shown to work for the reconstruction of large manmade structures (such as bridges) and urban buildings

From engineering geosciences mapping towards sustainable urban planning

Maps are of key topical importance in urban geoscience and engineering practice, mainly in field data synthesis and communication related to a number of fields, such as geomatic techniques, applied geology and geomorphology, engineering geology, soil and rock geotechnics, slope geotechnics, subsurface site geotechnical investigations, urban hydrology, hydraulics and sanitation, coastal zones management, urban geoarcheology and heritage, planning and land use. The value of preparing engineering geoscience maps and plans specificallyfor urban engineering purposes are still a challenging task, particularly to end-users and planners. Nowadays, the application of Geographic Information Systems to geosciences and engineering has become more common. This paper emphasises the importance of an accurate ground field survey and inventory at several scales, GIS mapping and databases, and integrated multidisciplinary urban studies as useful tools to support a sustainable land use planning. Some selected sites are highlighted to demonstrate the importance of urban mapping for land use planning. Thus, in this study the significance of a smart urban geoscience approach is stressed.info:eu-repo/semantics/publishedVersio

Geomorphology of the northwestern Kurdistan Region of Iraq: landscapes of the Zagros Mountains drained by the Tigris and Great Zab Rivers

We present the geomorphological map of the northwestern part of the Kurdistan Region of Iraq, where the landscape expresses the tectonic activity associated with the Arabia-Eurasia convergence and Neogene climate change. These processes influenced the evolution of landforms and fluvial pathways, where major rivers Tigris, Khabur, and Great Zab incise the landscape of Northeastern Mesopotamia Anticlinal ridges and syncline trough compose the Zagros orogen. The development of water and wind gaps, slope, and karsts processes in the highlands and the tilting of fluvial terraces in the flat areas are the main evidence of the relationship between tectonics, climate variations and geomorphological processes. During the Quaternary, especially after the Last Glacial Maximum, fluctuating arid and wet periods also influenced local landforms and fluvial patterns of the area. Finally, the intensified Holocene human occupation and agricultural activities during the passage to more complex societies over time impacted the evolution of the landscape in this part of Mesopotamia

Mechanical and electrical characterization

Carbon fiber laminates and sandwich structures are widely used due to their extraordinary mechanical performance (high specific strength, specific modulus, resistance to corrosion and resistance to fatigue), in the case of sandwiches, the high performance of the carbon laminates can be increased by the low density of the core. Besides that, carbon fiber is a conductive material, beyond its mechanical advantages, it has the potential to be used as a self-sensing material. This work aimed to analyze the use of sandwich composite structures in aircraft, to manufacture, and to study the mechanical and electrical properties of a sandwich composed of two carbon fiber faces and a structural foam core. The experimental work started with a study on the foam core, to access the impact of the adhesive curing temperature in the foam’s mechanical behavior. There was an increase on the ductility of the foam, but the flexural strength did not suffer significant changes. Posteriorly, three-point bending tests were carried out on carbon fiber laminates, with two different geometries, so compressive and tensile failures could be studied. The specimens that failed to compression showed a flexural strength of 1066.21±4.7% MPa, while the ones that failed under a flexural stress of 1238.49±7% MPa. The sandwich specimens with different adhesive bonds and geometries were tested and the short samples with reinforced bond failed to compression under a flexural stress of 100 MPa ± 5%, while the long samples showed several failure modes under a flexural stress of 86 MPa ± 7%. An electromechanical analysis was conducted to study the piezoresistive response of the sandwich skins. From this analysis was possible to show that there is indeed a relation between the electrical resistance and the applied strain.Os laminados de fibra de carbono e as estruturas em sanduíche são amplamente utilizadas devido ao seu elevado desempenho mecânico (elevada resistência específica, módulo específico, resistência à corrosão e resistência à fadiga), que no caso das sanduíches, é acrescido da baixa densidade do núcleo. Além disso, a fibra de carbono é um material condutor, portanto para além das vantagens mecânicas, este material tem o potencial de ser utilizado como um material capaz de detetar dano e deformação sem que a necessidade de sensores. Neste trabalho pretendeu-se analisar o uso de estruturas compósitas em sanduíches em aeronaves, fabricar e estudar as propriedades mecânicas e elétricas de uma sanduíche composta por duas faces de fibra de carbono e um núcleo de espuma estrutural. Na primeira fase do trabalho experimental, foi feito um estudo sobre o núcleo de espuma, com o objetivo de averiguar qual o impacto da temperatura de cura do adesivo. Houve um aumento da ductilidade do material, mas sem impactos significativos ao nível da tensão de cedência. Posteriormente, foram testados à flexão laminados de fibra de carbono, com duas geometrias de forma a serem obtidos modos de falha à compressão e à tração. Verificou-se que os laminados apresentaram um modo de dano nas fibras à compressão, para uma tensão na ordem dos 1066 MPa ± 5%, enquanto que os laminados cuja ruína ocorreu na face à tração a uma tensão na ordem dos 1238 MPa ± 7%. As amostras de sanduíches com diferentes composições adesivas e geometrias foram testadas e as de menor dimensão com reforço adesivo cederam à compressão com uma tensão máxima na ordem de 100 MPa ± 5%, enquanto que as de maior dimensão apresentaram diversos modos de falha a uma tensão na ordem dos 86 MPa ± 7%. Recorrendo a uma análise eletromecânica, foi estudada a resposta piezoresistiva dos laminados constituintes das faces das sanduíches. Desta análise foi possível demonstrar que existe efetivamente uma relação entre a resistência elétrica e a deformação do material

Localised strain and doping of 2D materials

There is a growing interest in 2D materials-based devices as the replacement for established materials, such as silicon and metal oxides in microelectronics and sensing, respectively. However, the atomically thin nature of 2D materials makes them susceptible to slight variations caused by their immediate environment, inducing doping and strain, which can vary between, and even microscopically within, devices. One of the misapprehensions for using 2D materials is the consideration of unanimous intrinsic properties over different support surfaces. The interfacial interaction, intrinsic structural disorder and external strain modulate the properties of 2D materials and govern the device performance. The understanding, measurement and control of these factors are thus one of the significant challenges for the adoption of 2D materials in industrial electronics, sensing, and polymer composites. This topical review provides a comprehensive overview of the effect of strain-induced lattice deformation and its relationship with physical and electronic properties. Using the example of graphene and MoS2 (as the prototypical 2D semiconductor), we rationalise the importance of scanning probe techniques and Raman spectroscopy to elucidate strain and doping in 2D materials. These effects can be directly and accurately characterised through Raman shifts in a non-destructive manner. A generalised model has been presented that deconvolutes the intertwined relationship between strain and doping in graphene and MoS2 that could apply to other members of the 2D materials family. The emerging field of straintronics is presented, where the controlled application of strain over 2D materials induces tuneable physical and electronic properties. These perspectives highlight practical considerations for strain engineering and related microelectromechanical applications

Roadmap on digital holography [Invited]

This Roadmap article on digital holography provides an overview of a vast array of research activities in the field of digital holography. The paper consists of a series of 25 sections from the prominent experts in digital holography presenting various aspects of the field on sensing, 3D imaging and displays, virtual and augmented reality, microscopy, cell identification, tomography, label-free live cell imaging, and other applications. Each section represents the vision of its author to describe the significant progress, potential impact, important developments, and challenging issues in the field of digital holography

The 2nd International Electronic Conference on Applied Sciences

This book is focused on the works presented at the 2nd International Electronic Conference on Applied Sciences, organized by Applied Sciences from 15 to 31 October 2021 on the MDPI Sciforum platform. Two decades have passed since the start of the 21st century. The development of sciences and technologies is growing ever faster today than in the previous century. The field of science is expanding, and the structure of science is becoming ever richer. Because of this expansion and fine structure growth, researchers may lose themselves in the deep forest of the ever-increasing frontiers and sub-fields being created. This international conference on the Applied Sciences was started to help scientists conduct their own research into the growth of these frontiers by breaking down barriers and connecting the many sub-fields to cut through this vast forest. These functions will allow researchers to see these frontiers and their surrounding (or quite distant) fields and sub-fields, and give them the opportunity to incubate and develop their knowledge even further with the aid of this multi-dimensional network