Jesus Fernandez_Hernandez

Dr. Jesus Fernandez_Hernandez

Department of Cartographic and Land Engineering Department, Higher Polytechnic School of Avila, University of Salamanca, Hornos Caleros, 50 05003 Avila, Spain
orcid

Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
20 June 2017 in Remote Sensing
Verified
Journal Article
Open access
PDF file
LFLuis López Fernández
Luis López Fernández
Susana LagüelaSusana Lagüela
Susana Lagüela
JFJesus Fernandez_Hernandez
Jesus Fernandez_Hernandez
Diego Gonzalez-AguileraDiego Gonzalez-Aguilera
Diego Gonzalez-Aguilera
A low-cost unmanned aerial platform (UAV) equipped with RGB (Red, Green, Blue) and thermographic sensors is used for the acquisition of all the data needed for the automatic detection and evaluation of thermal pathologies on photovoltaic (PV) surfaces and geometric defects in the mounting on photovoltaic power stations. RGB imagery is used for the generation of a georeferenced 3D point cloud through digital image preprocessing, photogrammetric and computer vision algorithms. The point cloud is complemented with temperature values measured by the thermographic sensor and with intensity values derived from the RGB data in order to obtain a multidimensional product (5D: 3D geometry plus temperature and intensity on the visible spectrum). A segmentation workflow based on the proper integration of several state-of-the-art geomatic and mathematic techniques is applied to the 5D product for the detection and sizing of thermal pathologies and geometric defects in the mounting in the PV panels. It consists of a three-step segmentation procedure, involving first the geometric information, then the radiometric (RGB) information, and last the thermal data. No configuration of parameters is required. Thus, the methodology presented contributes to the automation of the inspection of PV farms, through the maximization of the exploitation of the data acquired in the different spectra (visible and thermal infrared bands). Results of the proposed workflow were compared with a ground truth generated according to currently established protocols and complemented with a topographic survey. The proposed methodology was able to detect all pathologies established by the ground truth without adding any false positives. Discrepancies in the measurement of damaged surfaces regarding established ground truth, which can reach the 5% of total panel surface for the visual inspection by an expert operator, decrease with the proposed methodology under the 2%. The geometric evaluation of the facilities presents discrepancies regarding the ground truth lower than one degree for angular parameters (azimuth and tilt) and lower than 0.05 m2 for the area of each solar panel.

22 January 2022 in Remote Sensing
Verified
Journal Article
Open access
PDF file
Miguel Ángel Maté-GonzálezMiguel Ángel Maté-González
Miguel Ángel Maté-González
Jesús Rodríguez-HernándezJesús Rodríguez-Hernández
Jesús Rodríguez-Hernández
Cristina Sáez BlázquezCristina Sáez Blázquez
Cristina Sáez Blázquez
LIBERTAD TROITIÑO TORRALBALIBERTAD TROITIÑO TORRALBA
LIBERTAD TROITIÑO TORRALBA
Luis Javier Sánchez AparicioLuis Javier Sánchez Aparicio
Luis Javier Sánchez Aparicio
JÁJesús R. Álvarez-Sanchís
Jesús R. Álvarez-Sanchís
This research presents a virtual tour performed on the oppidum of Ulaca, one of the most relevant archaeological sites of the Iberian Peninsula during the Late Iron Age (ca. 400–50 BC). Beyond the clear benefits of the tool to the interpretation, dissemination, and knowledge of the mentioned archaeological site and its surroundings, the novelty of this research is the implementation of the platform in alternative scenarios and purposes. In this way, the present work verifies how the access to multi-source and spatially geolocated information in the same tool (working as a geospatial database) allows the promotion of cross-sectional investigations in which different specialists intervene. This peculiarity is also considered useful to promote tourism with an interest beyond the purely historical/archaeological side. Likewise, the possibility of storing and managing a large amount of information in different formats facilitates the investigation in the contexts of excavations and archaeological or environmental works. In this sense, the use of this kind of tool for the study of cultural landscapes is especially novel. In order to better contextualize the potential of the virtual tour presented here, an analysis about the challenges and possibilities of implementing this tool in environments such as the Ulaca oppidum is performed. The selected site stands out for: (i) being in a unique geological, environmental and ecological context, allowing us to appreciate how human beings have modified the landscape over time; (ii) presenting numerous visible archaeological remains with certain conservation problems; and (iii) not having easy access for visitors.

22 April 2021 in Sensors
Verified
Journal Article
Open access
PDF file
Miguel Ángel Maté-GonzálezMiguel Ángel Maté-González
Miguel Ángel Maté-González
Cristina Sáez BlázquezCristina Sáez Blázquez
Cristina Sáez Blázquez
PCPedro Carrasco
Pedro Carrasco
Jesús Rodríguez-HernándezJesús Rodríguez-Hernández
Jesús Rodríguez-Hernández
JFJesus Fernandez_Hernandez
Jesus Fernandez_Hernandez
JÁJesús R. Álvarez-Sanchís
Jesús R. Álvarez-Sanchís
This research focuses on the study of the ruins of a large building known as “El Torreón” (the Tower), belonging to the Ulaca oppidum (Solosancho, Province of Ávila, Spain). Different remote sensing and geophysical approaches have been used to fulfil this objective, providing a better understanding of the building’s functionality in this town, which belongs to the Late Iron Age (ca. 300–50 BCE). In this sense, the outer limits of the ruins have been identified using photogrammetry and convergent drone flights. An additional drone flight was conducted in the surrounding area to find additional data that could be used for more global interpretations. Magnetometry was used to analyze the underground bedrock structure and ground penetrating radar (GPR) was employed to evaluate the internal layout of the ruins. The combination of these digital methodologies (surface and underground) has provided a new perspective for the improved interpretation of “El Torreón” and its characteristics. Research of this type presents additional guidelines for better understanding of the role of this structure with regards to other buildings in the Ulaca oppidum. The results of these studies will additionally allow archaeologists to better plan future interventions while presenting new data that can be used for the interpretation of this archaeological complex on a larger scale.

9 March 2020 in Energies
Verified
Journal Article
Open access
PDF file
Cristina Sáez BlázquezCristina Sáez Blázquez
Cristina Sáez Blázquez
Laura PiedeloboLaura Piedelobo
Laura Piedelobo
JFJesus Fernandez_Hernandez
Jesus Fernandez_Hernandez
Ignacio Martín NietoIgnacio Martín Nieto
Ignacio Martín Nieto
Arturo Farfan MartínArturo Farfan Martín
Arturo Farfan Martín
Diego Gonzalez-AguileraDiego Gonzalez-Aguilera
Diego Gonzalez-Aguilera
Ground source heat pump (GSHP) systems are becoming popular in space heating and cooling applications. Despite this fact, in most countries, the role of this energy is not as important as it should be nowadays according to its capabilities for energy generation without CO2 emissions, mainly due to the lack of technical knowledge about GSHP performance. The analysis of the physical processes that take part in the geothermal exchanges is necessary to allow the optimal exploitation of the geothermal resources. For all the above, an experimental geothermal device was built in the laboratory to control the phenomena that take place in a borehole heat exchanger (BHE). A 1-m high single-U heat exchanger was inserted in the center of a polyethylene container which also included granular material (surrounding ground) and the grouting material. Temperature sensors were situated in different positions of the experimental setup. Physical processes are evaluated to finally validate the model. Numerous applications can be developed from the experimental BHE. In this research, the determination of the thermal conductivity of the material used as medium was carried out. Results of this parameter were also compared with the ones obtained from the use of the KD2 Pro device.