2024
Autores
Bakon, M; Teixeira, AC; Padua, L; Morais, R; Papco, J; Kubica, L; Rovnak, M; Perissin, D; Sousa, JJ;
Publicação
REMOTE SENSING
Abstract
Synthetic aperture radar (SAR) technology has emerged as a pivotal tool in viticulture, offering unique capabilities for various applications. This study provides a comprehensive overview of the current state-of-the-art applications of SAR in viticulture, highlighting its significance in addressing key challenges and enhancing viticultural practices. The historical evolution and motivations behind SAR technology are also provided, along with a demonstration of its applications within viticulture, showcasing its effectiveness in various aspects of vineyard management, including delineating vineyard boundaries, assessing grapevine health, and optimizing irrigation strategies. Furthermore, future perspectives and trends in SAR applications in viticulture are discussed, including advancements in SAR technology, integration with other remote sensing techniques, and the potential for enhanced data analytics and decision support systems. Through this article, a comprehensive understanding of the role of SAR in viticulture is provided, along with inspiration for future research endeavors in this rapidly evolving field, contributing to the sustainable development and optimization of vineyard management practices.
2024
Autores
López, A; Ogayar, CJ; Feito, FR; Sousa, JJ;
Publicação
REMOTE SENSING
Abstract
Classifying grapevine varieties is crucial in precision viticulture, as it allows for accurate estimation of vineyard row growth for different varieties and ensures authenticity in the wine industry. This task can be performed with time-consuming destructive methods, including data collection and analysis in the laboratory. In contrast, unmanned aerial vehicles (UAVs) offer a markedly more efficient and less restrictive method for gathering hyperspectral data, even though they may yield data with higher levels of noise. Therefore, the first task is the processing of these data to correct and downsample large amounts of data. In addition, the hyperspectral signatures of grape varieties are very similar. In this study, we propose the use of a convolutional neural network (CNN) to classify seventeen different varieties of red and white grape cultivars. Instead of classifying individual samples, our approach involves processing samples alongside their surrounding neighborhood for enhanced accuracy. The extraction of spatial and spectral features is addressed with (1) a spatial attention layer and (2) inception blocks. The pipeline goes from data preparation to dataset elaboration, finishing with the training phase. The fitted model is evaluated in terms of response time, accuracy and data separability and is compared with other state-of-the-art CNNs for classifying hyperspectral data. Our network was proven to be much more lightweight by using a limited number of input bands (40) and a reduced number of trainable weights (560 k parameters). Hence, it reduced training time (1 h on average) over the collected hyperspectral dataset. In contrast, other state-of-the-art research requires large networks with several million parameters that require hours to be trained. Despite this, the evaluated metrics showed much better results for our network (approximately 99% overall accuracy), in comparison with previous works barely achieving 81% OA over UAV imagery. This notable OA was similarly observed over satellite data. These results demonstrate the efficiency and robustness of our proposed method across different hyperspectral data sources.
2024
Autores
Couto, D; Davies, S; Sousa, J; Cunha, A;
Publicação
Procedia Computer Science
Abstract
Interferometric Synthetic Aperture Radar (InSAR) revolutionizes surface study by measuring precise ground surface changes. Phase unwrapping, a key challenge in InSAR, involves removing ambiguity in measured phase. Deep learning algorithms like Generative Adversarial Networks (GANs) offer a potential solution for simplifying the unwrapping process. This work evaluates GANs for InSAR phase unwrapping, replacing SNAPHU with GANs. GANs achieve significantly faster processing times (2.38 interferograms per minute compared to SNAPHU's 0.78 interferograms per minute) with minimal quality degradation. A comparison of SBAS results shows that approximately 84% of GANs points are within 3 millimeters of SNAPHU. These results represent a significant advancement in phase unwrapping methods. While this experiment does not declare a definitive winner, it demonstrates that GANs are a viable alternative in certain scenarios and may replace SNAPHU as the preferred unwrapping method. © 2024 The Author(s). Published by Elsevier B.V.
2024
Autores
Teixeira, I; Sousa, J; Cunha, A;
Publicação
Procedia Computer Science
Abstract
Port wine plays a crucial role in the Douro region in Portugal, providing significant economic support and international recognition. The efficient and sustainable management of the wine sector is of utmost importance, which includes the verification of abandoned vineyard plots in the region, covering an area of approximately 250,000 hectares. The manual analysis of aerial images for this purpose is a laborious and resource-intensive task. However, several artificial intelligence (AI) methods are available to assist in this process. This paper presents the development of AI models, specifically deep learning models, for the automatic detection of abandoned vineyards using aerial images. A private image database was expanded, containing a larger collection of images with both abandoned and non-abandoned vineyards. Multiple AI algorithms, including Convolutional Neural Networks (CNNs) and Vision Transformers (ViTs), were explored for classification. The results, particularly with the ViTs approach, achieved high accuracy and demonstrated the effectiveness of automatic detection, with the ViT models achieving an accuracy of 99.37% and an F1-score of 98.92%. The proposed AI models provide valuable tools for monitoring and decision-making related to vineyard abandonment. © 2024 The Author(s). Published by Elsevier B.V.
2024
Autores
Carneiro, GA; Cunha, A; Sousa, J;
Publicação
Abstract
2024
Autores
Carneiro, GA; Cunha, A; Sousa, J;
Publicação
Abstract
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