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Publications

Publications by CRIIS

2021

QVigourMap: A GIS Open Source Application for the Creation of Canopy Vigour Maps

Authors
Duarte, L; Teodoro, AC; Sousa, JJ; Padua, L;

Publication
AGRONOMY-BASEL

Abstract
In a precision agriculture context, the amount of geospatial data available can be difficult to interpret in order to understand the crop variability within a given terrain parcel, raising the need for specific tools for data processing and analysis. This is the case for data acquired from Unmanned Aerial Vehicles (UAV), in which the high spatial resolution along with data from several spectral wavelengths makes data interpretation a complex process regarding vegetation monitoring. Vegetation Indices (VIs) are usually computed, helping in the vegetation monitoring process. However, a crop plot is generally composed of several non-crop elements, which can bias the data analysis and interpretation. By discarding non-crop data, it is possible to compute the vigour distribution for a specific crop within the area under analysis. This article presents QVigourMaps, a new open source application developed to generate useful outputs for precision agriculture purposes. The application was developed in the form of a QGIS plugin, allowing the creation of vigour maps, vegetation distribution maps and prescription maps based on the combination of different VIs and height information. Multi-temporal data from a vineyard plot and a maize field were used as case studies in order to demonstrate the potential and effectiveness of the QVigourMaps tool. The presented application can contribute to making the right management decisions by providing indicators of crop variability, and the outcomes can be used in the field to apply site-specific treatments according to the levels of vigour.

2021

Monitoring of an embankment dam in southern Spain based on Sentinel-1 Time-series InSAR

Authors
Ruiz Armenteros, AM; Marchamalo Sacrsitan, M; Bakon, M; Lamas Fernandez, F; Delgado, JM; Sanchez Ballesteros, V; Papco, J; Gonzalez Rodrigo, B; Lazecky, M; Perissin, D; Sousa, JJ;

Publication
INTERNATIONAL CONFERENCE ON ENTERPRISE INFORMATION SYSTEMS / INTERNATIONAL CONFERENCE ON PROJECT MANAGEMENT / INTERNATIONAL CONFERENCE ON HEALTH AND SOCIAL CARE INFORMATION SYSTEMS AND TECHNOLOGIES 2020 (CENTERIS/PROJMAN/HCIST 2020)

Abstract
Deformation monitoring is a common practice in most of dams to ensure their structural health and safety status. Systematic monitoring is frequently carried out by means of geotechnical sensors and geodetic techniques that, although very precise an accurate, can be time-consuming and economically costly. Remote sensing techniques are proved to be very effective in assessing deformation. Changes in the structure, shell or associated infrastructures of dams, including adjacent slopes, can be efficiently recorded by using satellite Synthetic Aperture Radar Inteferometry (InSAR) techniques, in particular, Muti-Temporal InSAR time-series analyses. This is a mature technology nowadays but not very common as a routine procedure for dam monitoring. Today, thanks to the availability of spaceborne satellites with high spatial resolution SAR images and short revisit times, this technology is a powerful cost-effective way to monitor millimeter-level displacements of the dam structure and its surroundings. What is more, the potential of the technique is increased since the Copernicus C-band SAR Sentinel-1 satellites are in orbit, due to the high revisit time of 6 days and the free data availability. ReMoDams is a Spanish research project devoted to provide the deformation monitoring of several embankments dams using advances time-series InSAR techniques. One of these dams is The Arenoso dam, located in the province of Cordova (southern Spain). This dam has been monitored using Sentinel-1 SAR data since the beginning of the mission in 2014. In this paper, we show the processing of 382 SLC SAR images both in ascending and descending tracks until March 2019. The results indicate that the main displacement of the dam in this period is in the vertical direction with a rate in the order of -1 cm/year in the central part of the dam body. (C) 2020 The Authors. Published by Elsevier B.V.

2021

Simple method for identification of forest windthrows from Sentinel-1 SAR data incorporating PCA

Authors
Lazecky, M; Wadhwa, S; Mlcousek, M; Sousa, JJ;

Publication
INTERNATIONAL CONFERENCE ON ENTERPRISE INFORMATION SYSTEMS / INTERNATIONAL CONFERENCE ON PROJECT MANAGEMENT / INTERNATIONAL CONFERENCE ON HEALTH AND SOCIAL CARE INFORMATION SYSTEMS AND TECHNOLOGIES 2020 (CENTERIS/PROJMAN/HCIST 2020)

Abstract
We present outcomes from our experimental work towards identification of forest segments in Czech Jeseniky mountains damaged by a hurricane event on March 17, 2018. We have specifically processed Sentinel-1 satellite radar data and identified a functional methodology of extracting extents of the affected segments. The backscatter intensity of the damaged forest segments in Sentinel-1 images does not change significantly, subject to the sensitivity of the instrument. We have identified that a careful preprocessing of the data can lead to a state of possibility to identify edges of the affected areas in one of Principal Components (PC) generated from a set of dual-polarisation images before and after the event. In our case, these features were clearly visible in PC3 that was used in post-processing chain incorporating strong spatial filtering and edge detection routines. The identified damaged forest segments were validated by mapping during visiting one of the areas and by a comparison with multispectral satellite imagery, from data taken following year (as the damaged forest areas were already cleared and not regenerated). The approach can bring advantage in possibility of early preliminary mapping of the forest damages. (C) 2021 The Authors. Published by Elsevier B.V.

2021

Prototyping IoT-Based Virtual Environments: An Approach toward the Sustainable Remote Management of Distributed Mulsemedia Setups

Authors
Adao, T; Pinho, T; Padua, L; Magalhaes, LG; Sousa, JJ; Peres, E;

Publication
APPLIED SCIENCES-BASEL

Abstract
Business models built upon multimedia/multisensory setups delivering user experiences within disparate contexts-entertainment, tourism, cultural heritage, etc.-usually comprise the installation and in-situ management of both equipment and digital contents. Considering each setup as unique in its purpose, location, layout, equipment and digital contents, monitoring and control operations may add up to a hefty cost over time. Software and hardware agnosticity may be of value to lessen complexity and provide more sustainable management processes and tools. Distributed computing under the Internet of Things (IoT) paradigm may enable management processes capable of providing both remote control and monitoring of multimedia/multisensory experiences made available in different venues. A prototyping software to perform IoT multimedia/multisensory simulations is presented in this paper. It is fully based on virtual environments that enable the remote design, layout, and configuration of each experience in a transparent way, without regard of software and hardware. Furthermore, pipelines to deliver contents may be defined, managed, and updated in a context-aware environment. This software was tested in the laboratory and was proven as a sustainable approach to manage multimedia/multisensory projects. It is currently being field-tested by an international multimedia company for further validation.

2021

Virtual Environments & Precision Viticulture: A Case Study

Authors
Lourenço, J; Teixeira, J; Carvalho, P; Pádua, L; Adão, T; Peres, E; Sousa, JJ;

Publication
IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2021, Brussels, Belgium, July 11-16, 2021

Abstract
The development and implementation of a virtual environment that aims to support farmers in managing their land and crops in a more sustainable way is presented in this paper. It allows both textual and 3D visualization of crop-related biophysical parameters, such as height, volume and length. Moreover, the latter can be dynamically altered according to various criteria. A case study was conducted in a Portuguese vineyard. The application was developed using the Unity software, while a real agricultural data feed was provided by mySense interface. The virtual environment can be seen as a valuable decision support system to assist farmers.

2021

Geohazards Monitoring and Assessment Using Multi-Source Earth Observation Techniques

Authors
Sousa, JJ; Liu, G; Fan, JH; Perski, Z; Steger, S; Bai, SB; Wei, LH; Salvi, S; Wang, Q; Tu, JA; Tong, LQ; Mayrhofer, P; Sonnenschein, R; Liu, SJ; Mao, YC; Tolomei, C; Bignami, C; Atzori, S; Pezzo, G; Wu, LX; Yan, SY; Peres, E;

Publication
REMOTE SENSING

Abstract
Geological disasters are responsible for the loss of human lives and for significant economic and financial damage every year. Considering that these disasters may occur anywhere-both in remote and/or in highly populated areas-and anytime, continuously monitoring areas known to be more prone to geohazards can help to determine preventive or alert actions to safeguard human life, property and businesses. Remote sensing technology-especially satellite-based-can be of help due to its high spatial and temporal coverage. Indeed, data acquired from the most recent satellite missions is considered suitable for a detailed reconstruction of past events but also to continuously monitor sensitive areas on the lookout for potential geohazards. This work aims to apply different techniques and methods for extensive exploitation and analysis of remote sensing data, with special emphasis given to landslide hazard, risk management and disaster prevention. Multi-temporal SAR (Synthetic Aperture Radar) interferometry, SAR tomography, high-resolution image matching and data modelling are used to map out landslides and other geohazards and to also monitor possible hazardous geological activity, addressing different study areas: (i) surface deformation of mountain slopes and glaciers; (ii) land surface displacement; and (iii) subsidence, landslides and ground fissure. Results from both the processing and analysis of a dataset of earth observation (EO) multi-source data support the conclusion that geohazards can be identified, studied and monitored in an effective way using new techniques applied to multi-source EO data. As future work, the aim is threefold: extend this study to sensitive areas located in different countries; monitor structures that have strategic, cultural and/or economical relevance; and resort to artificial intelligence (AI) techniques to be able to analyse the huge amount of data generated by satellite missions and extract useful information in due course.

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