417 research outputs found

    Hyperspectral Remote Sensing Data Analysis and Future Challenges

    Full text link

    Aplicación del análisis de imagen hiperespectral y tridimensional al control de procesos y productos en la industria harinera y sus derivados

    Full text link
    Tesis por compendio[EN] This work is focused on studying of hyperspectral and structured light based tridimensional image analysis about their application on quality and process control of cereal flour industry and derived products. The structured light based tridimensional image analysis has been used to develop a bread dough dynamic fermentation control system. Descriptors obtained from dough shape evolution were used to describe differences between wheat flour batches during fermentation process. In the same way, that system was used to characterize the effect of new ingredients on fermentation process. Those behaviors were analyzed joint to the intern structure of dough during the process, establishing relationships between it and the tridimensional information. Differences in fermentation process were also studied using hyperspectral image analysis. Flours were analyzed using the obtained diffuse reflectance spectra, which contained information within 400-1000 nm of wavelength range. Differences in several spectral bands were correlated with fundamental components of flours such as gluten. That spectral characterization of flours was used to detect adulterations with different grains. Adulterations until 2, 5% of oat, sorghum and corn were detected both flour and bread crumb. The hyperspectral image analysis was also used to control the heat treatment of wheat and oat flours, where spectral information was related to properties of end products.[ES] El presente trabajo está centrado en el estudio de los sistemas de análisis de imagen hiperespectral y tridimensional basado en luz estructurada para su aplicación en el control de procesos y calidad de la industria harinera y de sus derivados. El sistema de imagen tridimensional basado en luz estructurada fue la base para el desarrollo de un sistema de monitorización en continuo de la fase de fermentación de masas panarias. A partir de descriptores desarrollados relacionados con la variación de la forma del producto durante la operación, se establecieron diferencias entre lotes de harinas de trigo y describió el comportamiento de masas reformuladas con nuevos ingredientes. Dicho comportamiento fue analizado en conjunto con la estructura interna de la masa durante la operación, estableciendo relaciones concretas entre esta y la información obtenida a partir de las imágenes. Las diferencias de comportamiento durante la operación de fermentación también fueron estudiadas mediante el sistema de imagen hiperespectral. En este caso, las harinas fueron analizadas directamente mediante imágenes espectrales, obteniendo espectros de reflectancia difusa en el rango de longitudes de onda 400-1000, donde se observaron diferencias en determinadas bandas del espectro. Dichas diferencias fueron correlacionadas con determinados componentes fundamentales como el gluten. La caracterización espectral de la harina de trigo se utilizó posteriormente para la detección de cereales diferentes mezclados con esta. Adulteraciones de hasta un 2,5% de avena, sorgo y maíz fueron detectadas tanto en harina como en panes de trigo. El análisis de imagen hiperespectral también ha sido aplicado al control del tratamiento térmico de harinas de trigo y avena, donde se ha conseguido relacionar la información espectral con las características del producto final.[CA] El present treball està centrat en l'estudi dels sistemes d'anàlisis d'imatge hiperespectral i tridimensional basat en llum estructurada per a la seua aplicació en el control de processos i qualitat de la indústria farinera i dels seus derivats. El sistema d'imatge tridimensional basat en llum estructurada va ser la base per al desenvolupament d'un sistema de monitoratge en continu de la fase de fermentació de masses panaries. A partir dels descriptors desenvolupats relacionats amb la variació de la forma del producte durant l'operació, es van establir diferències entre lots de farines de blat i es va descriure el comportament de masses reformulades amb nous ingredients. Aquest comportament va ser analitzat en conjunt amb l'estructura interna de la massa durant l'operació, establint relacions concretes entre aquesta i la informació obtinguda a partir de les imatges. Les diferències de comportament durant l'operació de fermentació també van ser estudiades mitjançant el sistema d'imatge hiperespectral. En aquest cas, les farines van ser analitzades directament mitjançant imatges espectrals, obtenint espectres de reflectància difusa en el rang de longituds d'ona 400-1000, on es van observar diferències en determinades bandes de l'espectre. Aquestes diferències van ser correlacionades amb determinats components fonamentals com el gluten. La caracterització espectral de la farina de blat es va utilitzar posteriorment per a la detecció de cereals diferents barrejats amb aquesta. Adulteracions de fins a un 2,5% de civada, sorgo i dacsa van ser detectades tant en farina com en pans de blat. L'anàlisi d'imatge hiperespectral també ha sigut aplicat al control del tractament tèrmic de farines de blat i civada, on s'ha aconseguit relacionar la informació espectral amb les característiques del producte final.Verdú Amat, S. (2016). Aplicación del análisis de imagen hiperespectral y tridimensional al control de procesos y productos en la industria harinera y sus derivados [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/65354TESISPremios Extraordinarios de tesis doctoralesCompendi

    Spatial Analysis for Landscape Changes

    Get PDF
    Recent increasing trends of the occurrence of natural and anthropic processes have a strong impact on landscape modification, and there is a growing need for the implementation of effective instruments, tools, and approaches to understand and manage landscape changes. A great improvement in the availability of high-resolution DEMs, GIS tools, and algorithms of automatic extraction of landform features and change detections has favored an increase in the analysis of landscape changes, which became an essential instrument for the quantitative evaluation of landscape changes in many research fields. One of the most effective ways of investigating natural landscape changes is the geomorphological one, which benefits from recent advances in the development of digital elevation model (DEM) comparison software and algorithms, image change detection, and landscape evolution models. This Special Issue collects six papers concerning the application of traditional and innovative multidisciplinary methods in several application fields, such as geomorphology, urban and territorial systems, vegetation restoration, and soil science. The papers include multidisciplinary studies that highlight the usefulness of quantitative analyses of satellite images and UAV-based DEMs, the application of Landscape Evolution Models (LEMs) and automatic landform classification algorithms to solve multidisciplinary issues of landscape changes. A review article is also presented, dealing with the bibliometric analysis of the research topic

    Advancements in Multi-temporal Remote Sensing Data Analysis Techniques for Precision Agriculture

    Get PDF
    L'abstract è presente nell'allegato / the abstract is in the attachmen

    3D Remote Sensing Applications in Forest Ecology: Composition, Structure and Function

    Get PDF
    Dear Colleagues, The composition, structure and function of forest ecosystems are the key features characterizing their ecological properties, and can thus be crucially shaped and changed by various biotic and abiotic factors on multiple spatial scales. The magnitude and extent of these changes in recent decades calls for enhanced mitigation and adaption measures. Remote sensing data and methods are the main complementary sources of up-to-date synoptic and objective information of forest ecology. Due to the inherent 3D nature of forest ecosystems, the analysis of 3D sources of remote sensing data is considered to be most appropriate for recreating the forest’s compositional, structural and functional dynamics. In this Special Issue of Forests, we published a set of state-of-the-art scientific works including experimental studies, methodological developments and model validations, all dealing with the general topic of 3D remote sensing-assisted applications in forest ecology. We showed applications in forest ecology from a broad collection of method and sensor combinations, including fusion schemes. All in all, the studies and their focuses are as broad as a forest’s ecology or the field of remote sensing and, thus, reflect the very diverse usages and directions toward which future research and practice will be directed

    A review of technical factors to consider when designing neural networks for semantic segmentation of Earth Observation imagery

    Full text link
    Semantic segmentation (classification) of Earth Observation imagery is a crucial task in remote sensing. This paper presents a comprehensive review of technical factors to consider when designing neural networks for this purpose. The review focuses on Convolutional Neural Networks (CNNs), Recurrent Neural Networks (RNNs), Generative Adversarial Networks (GANs), and transformer models, discussing prominent design patterns for these ANN families and their implications for semantic segmentation. Common pre-processing techniques for ensuring optimal data preparation are also covered. These include methods for image normalization and chipping, as well as strategies for addressing data imbalance in training samples, and techniques for overcoming limited data, including augmentation techniques, transfer learning, and domain adaptation. By encompassing both the technical aspects of neural network design and the data-related considerations, this review provides researchers and practitioners with a comprehensive and up-to-date understanding of the factors involved in designing effective neural networks for semantic segmentation of Earth Observation imagery.Comment: 145 pages with 32 figure

    Assessing the role of EO in biodiversity monitoring: options for integrating in-situ observations with EO within the context of the EBONE concept

    Get PDF
    The European Biodiversity Observation Network (EBONE) is a European contribution on terrestrial monitoring to GEO BON, the Group on Earth Observations Biodiversity Observation Network. EBONE’s aims are to develop a system of biodiversity observation at regional, national and European levels by assessing existing approaches in terms of their validity and applicability starting in Europe, then expanding to regions in Africa. The objective of EBONE is to deliver: 1. A sound scientific basis for the production of statistical estimates of stock and change of key indicators; 2. The development of a system for estimating past changes and forecasting and testing policy options and management strategies for threatened ecosystems and species; 3. A proposal for a cost-effective biodiversity monitoring system. There is a consensus that Earth Observation (EO) has a role to play in monitoring biodiversity. With its capacity to observe detailed spatial patterns and variability across large areas at regular intervals, our instinct suggests that EO could deliver the type of spatial and temporal coverage that is beyond reach with in-situ efforts. Furthermore, when considering the emerging networks of in-situ observations, the prospect of enhancing the quality of the information whilst reducing cost through integration is compelling. This report gives a realistic assessment of the role of EO in biodiversity monitoring and the options for integrating in-situ observations with EO within the context of the EBONE concept (cfr. EBONE-ID1.4). The assessment is mainly based on a set of targeted pilot studies. Building on this assessment, the report then presents a series of recommendations on the best options for using EO in an effective, consistent and sustainable biodiversity monitoring scheme. The issues that we faced were many: 1. Integration can be interpreted in different ways. One possible interpretation is: the combined use of independent data sets to deliver a different but improved data set; another is: the use of one data set to complement another dataset. 2. The targeted improvement will vary with stakeholder group: some will seek for more efficiency, others for more reliable estimates (accuracy and/or precision); others for more detail in space and/or time or more of everything. 3. Integration requires a link between the datasets (EO and in-situ). The strength of the link between reflected electromagnetic radiation and the habitats and their biodiversity observed in-situ is function of many variables, for example: the spatial scale of the observations; timing of the observations; the adopted nomenclature for classification; the complexity of the landscape in terms of composition, spatial structure and the physical environment; the habitat and land cover types under consideration. 4. The type of the EO data available varies (function of e.g. budget, size and location of region, cloudiness, national and/or international investment in airborne campaigns or space technology) which determines its capability to deliver the required output. EO and in-situ could be combined in different ways, depending on the type of integration we wanted to achieve and the targeted improvement. We aimed for an improvement in accuracy (i.e. the reduction in error of our indicator estimate calculated for an environmental zone). Furthermore, EO would also provide the spatial patterns for correlated in-situ data. EBONE in its initial development, focused on three main indicators covering: (i) the extent and change of habitats of European interest in the context of a general habitat assessment; (ii) abundance and distribution of selected species (birds, butterflies and plants); and (iii) fragmentation of natural and semi-natural areas. For habitat extent, we decided that it did not matter how in-situ was integrated with EO as long as we could demonstrate that acceptable accuracies could be achieved and the precision could consistently be improved. The nomenclature used to map habitats in-situ was the General Habitat Classification. We considered the following options where the EO and in-situ play different roles: using in-situ samples to re-calibrate a habitat map independently derived from EO; improving the accuracy of in-situ sampled habitat statistics, by post-stratification with correlated EO data; and using in-situ samples to train the classification of EO data into habitat types where the EO data delivers full coverage or a larger number of samples. For some of the above cases we also considered the impact that the sampling strategy employed to deliver the samples would have on the accuracy and precision achieved. Restricted access to European wide species data prevented work on the indicator ‘abundance and distribution of species’. With respect to the indicator ‘fragmentation’, we investigated ways of delivering EO derived measures of habitat patterns that are meaningful to sampled in-situ observations

    Learning the Structure of High-Dimensional Manifolds with Self-Organizing Maps for Accurate Information Extraction

    Get PDF
    This paper was submitted by the author prior to final official version. For official version please see http://hdl.handle.net/1911/70515This work aims to improve the capability of accurate information extraction from high-dimensional data, with a specific neural learning paradigm, the Self-Organizing Map (SOM). The SOM is an unsupervised learning algorithm that can faithfully sense the manifold structure and support supervised learning of relevant information from the data. Yet open problems regarding SOM learning exist. We focus on the following two issues. 1. Evaluation of topology preservation. Topology preservation is essential for SOMs in faithful representation of manifold structure. However, in reality, topology violations are not unusual, especially when the data have complicated structure. Measures capable of accurately quantifying and informatively expressing topology violations are lacking. One contribution of this work is a new measure, the Weighted Differential Topographic Function (WDTF), which differentiates an existing measure, the Topographic Function (TF), and incorporates detailed data distribution as an importance weighting of violations to distinguish severe violations from insignificant ones. Another contribution is an interactive visual tool, TopoView, which facilitates the visual inspection of violations on the SOM lattice. We show the effectiveness of the combined use of the WDTF and TopoView through a simple two-dimensional data set and two hyperspectral images. 2. Learning multiple latent variables from high-dimensional data. We use an existing two-layer SOM-hybrid supervised architecture, which captures the manifold structure in its SOM hidden layer, and then, uses its output layer to perform the supervised learning of latent variables. In the customary way, the output layer only uses the strongest output of the SOM neurons. This severely limits the learning capability. We allow multiple, k, strongest responses of the SOM neurons for the supervised learning. Moreover, the fact that different latent variables can be best learned with different values of k motivates a new neural architecture, the Conjoined Twins, which extends the existing architecture with additional copies of the output layer, for preferential use of different values of k in the learning of different latent variables. We also automate the customization of k for different variables with the statistics derived from the SOM. The Conjoined Twins shows its effectiveness in the inference of two physical parameters from Near-Infrared spectra of planetary ices

    Remote sensing image fusion on 3D scenarios: A review of applications for agriculture and forestry

    Get PDF
    Three-dimensional (3D) image mapping of real-world scenarios has a great potential to provide the user with a more accurate scene understanding. This will enable, among others, unsupervised automatic sampling of meaningful material classes from the target area for adaptive semi-supervised deep learning techniques. This path is already being taken by the recent and fast-developing research in computational fields, however, some issues related to computationally expensive processes in the integration of multi-source sensing data remain. Recent studies focused on Earth observation and characterization are enhanced by the proliferation of Unmanned Aerial Vehicles (UAV) and sensors able to capture massive datasets with a high spatial resolution. In this scope, many approaches have been presented for 3D modeling, remote sensing, image processing and mapping, and multi-source data fusion. This survey aims to present a summary of previous work according to the most relevant contributions for the reconstruction and analysis of 3D models of real scenarios using multispectral, thermal and hyperspectral imagery. Surveyed applications are focused on agriculture and forestry since these fields concentrate most applications and are widely studied. Many challenges are currently being overcome by recent methods based on the reconstruction of multi-sensorial 3D scenarios. In parallel, the processing of large image datasets has recently been accelerated by General-Purpose Graphics Processing Unit (GPGPU) approaches that are also summarized in this work. Finally, as a conclusion, some open issues and future research directions are presented.European Commission 1381202-GEU PYC20-RE-005-UJA IEG-2021Junta de Andalucia 1381202-GEU PYC20-RE-005-UJA IEG-2021Instituto de Estudios GiennesesEuropean CommissionSpanish Government UIDB/04033/2020DATI-Digital Agriculture TechnologiesPortuguese Foundation for Science and Technology 1381202-GEU FPU19/0010

    A novel spectral-spatial co-training algorithm for the transductive classification of hyperspectral imagery data

    Get PDF
    The automatic classification of hyperspectral data is made complex by several factors, such as the high cost of true sample labeling coupled with the high number of spectral bands, as well as the spatial correlation of the spectral signature. In this paper, a transductive collective classifier is proposed for dealing with all these factors in hyperspectral image classification. The transductive inference paradigm allows us to reduce the inference error for the given set of unlabeled data, as sparsely labeled pixels are learned by accounting for both labeled and unlabeled information. The collective inference paradigm allows us to manage the spatial correlation between spectral responses of neighboring pixels, as interacting pixels are labeled simultaneously. In particular, the innovative contribution of this study includes: (1) the design of an application-specific co-training schema to use both spectral information and spatial information, iteratively extracted at the object (set of pixels) level via collective inference; (2) the formulation of a spatial-aware example selection schema that accounts for the spatial correlation of predicted labels to augment training sets during iterative learning and (3) the investigation of a diversity class criterion that allows us to speed-up co-training classification. Experimental results validate the accuracy and efficiency of the proposed spectral-spatial, collective, co-training strategy
    corecore