Collaboration Stay of Susana Lagüela López at Delft University of Technology (The Netherlands)

The researcher Susana Lagüela López is doing a research stay in Delft University of Technology (TU Delft, august-october 2017), to reinforce her collaboration in the H2020 project MOSES (Managing crOp water Saving with Enterprise Services). In this stay, the researcher is optimizing the strategies developed in the previous visit for the generation of high temporal and spatial resolution images in the thermal band based on unmixing algorithms. In this way, the information required about superficial and subsuperficial temperatures will be obtained for its use in evapotranspiration models and the optimization of the water management in crop areas. Current areas of studio are the hydrographic area of Den Maas in The Netherlands and the region of Puglia in Italy. Current results of the study have been presented in the work: Generating high-temporal and spatial resolution TIR image data. M. Herrero-Huerta, S. Lagüela, S. M. Alfieri and M. Menenti (2017). Commission III, ICWG III/6. https://doi.org/10.5194/isprs-archives-XLII-2-W7-737-2017

Susana_Laguela_delft17

Visit of the researcher Erica Nocerino (3DOM group, Italy)

Erica_N_stayDuring the month of July, Erica Nocerino, researcher of the 3DOM group (3D Optical Metrology) from Bruno Kessler Foundation (Italy) was invited to the TIDOP research group in Avila. Her stay is part of a research line of new photogrammetric solutions for the evaluation of welded joints to advance the safety and protection of the constructions contributing to a greater security of the infrastructures, thanks to the rigor, objectivity and exhaustiveness in the first visual inspection phases. To this end, tilt-shift lenses were tested; such lenses make use of the Scheimpflug principle, which allows to adapt the shape of the depth of field to the extent of the subject of interest by the inclination of the lens with respect to the plane of the sensor.

Also, given the versatility of such systems, she carried out some experiments also in the field of Cultural Heritage, more specifically for the documentation of archaeological remains from different eras, to evaluate their capacity and potentiality.

Research Stay of Zazo del Dedo at the Laboratory of Hydraulics of the University of Beira Interior (Covilhã, Portugal)

Zazo_Stay_1From September 2016 to February 2017, Santiago Zazo del Dedo has developed a research stay at the Hydraulic Laboratory of the Department of Civil Engineering and Architecture (Faculty of Engineering) of the University of Beira Interior (Covilhã, Portugal) under the supervision of Doctors Cristina María Sena Fael and Pedro Gabriel Almeida (http://www.ubi.pt).

The stay consisted on the application of Artificial Vision techniques to study the evolution of fluvial morphodynamics in meandriform rivers and channels. Specifically, SfM (Structure from Motion) was used in order to 3D reconstruct the terrain through digital images acquired with a commercial DSLR camera. Two research lines were derived, the first one is focused on the transport of sediments as well as the morphodynamic changes on the thalweg; and the second one is focused on the river bank protection against fluvial erosion, where the geometry of the protection elements were analysed in relation with the morphodymanic of the thalweg. As a result, high-resolution 3D geometric models were obtained (point density: ≈2-3 points/mm², accuracy: ≈2 mm) as well as high resolution orthoimages (pixel size: 1 millimetre).

Zazo_Stay_3Zazo_Stay_2

 

Research and Collaboration Stay of Susana Lagüela López at Delft University of Technology (The Netherlands)

Dr. Susana Lagüela López developed a research stay at TU Delft from January to April 2016.

The stay consisted on the collaboration with H2020 project SIM (Smart Irrigation from soil Moisture forecast using satellite and hydro-meteo modelling) and ESA project Tiger for “Assessment of climate effect on crop water productivity using Earth observation data: case study of Doukkala-Western Morocco”.

For these projects, Susana has focused on multispectral image processing, particularly on the fusion of images from different satellites, in order to include the TIR (Thermal InfraRed) band in the bands analysed by satellites that miss it. In particular, the TIR band of the CBERS4 – IRM sensor, will be combined with the bands from SENTINEL 2, which miss the TIR band. The following steps are required, according to the Unmixing technique:

  • Analysis of the presence of cloud coverage in the images, which is performed through the analysis of their Gaussian curves. If the coverage percentage is low, the mean value of the images is subtracted in order to generate a smooth transition between images. If the cloud coverage is almost complete, the image is eliminated from the process.

Susana_1

  • Generation of TIR mosaic for the images covering the area under study. The mosaic is required in order to extend the coverage of the images to larger terrain areas, and facilitate the correspondence between images of different satellites, thus with different coverage. Next, overlapping between CBERS and Sentinel 2 images is computed, in order to compute the Sentinel 2 pixels inside each CBERS2 pixels.
  • Evaluation of the behaviour of the TIR band for the measurement of evapotranspiration phenomena. The results show that each soil use presents different behaviour under sun presence, with different reflectance values. As an example, in the vineyard region of Mendoza (Argentina), three different land uses are detected as a function of their reflectances: soil, uncovered rock, and vegetation (vineyards), with reflectance values of 75, 105 and 130, respectively.
  • Pixel classification is performed, using the conversion from RGB to LAB colour space, which allows the elimination of the luminosity effect (L) in order to make the process more stable. The process is performed for images of both satellites, in order to compute the values of the new pixels created for CBERS images as a function of the pixels contained in them from Sentinel images.

 

The work will continue to be developed during the months of October 2016 – January 2017, so more news are to come!

Susana_4


 

Página 1 de 3123
×
Análisis termográfico de edificios

 

El uso de la termografía infrarroja comMapaEnergeticoo técnica sobradamente provada para la inspección de edificios y localización de patologías como fugas de aire, humedades, etc. Nos permite realizar un examen visual “in-situ” de calidad de los objetos de estudio gracias a la posibilidad de visualizar en tiempo real los resultados pudiendo detectar sin dificultad los desperfectos o elementos característicos de estos. Estas técnicas de medición cualitativa nos proporcionan la posibilidad de realizar inspecciones rápidas y eficaces sin contacto directo con el objeto y de forma no destructiva, lo que disminuye tanto el riesgo de incidentes para los operarios como los daños producidos en los propios objetos de estudio ocasionados por otras técnicas intrusivas. Además, también se ha demostrado la utilidad de la termografía infrarroja como técnica puramente de medida a través de su utilización para el cálculo de propiedades termofísicas de materiales tales como difusividad y transmitancia térmica.

En el caso de termografía cualitativa, las publicaciones existentes tratan de estudios realizados in-situ, principalmente en edificios históricos o elementos del patrimonio cultural, mientras que los estudios cualitativos se realizan, en la mayor parte de los casos, en laboratorios sobre muestras de tamaño limitado. En aquellos casos en los que se han realizado estudios termográficos cuantitativos sobre edificios in-situ, los valores de temperatura son empleados con el objetivo de obtener propiedades termofísicas (conductancia térmica) reales del cerramiento, sin embargo su distribución espacial no es considerada.

Conjugar ambas aplicaciones permitirá la automatización del cálculo de pérdidas de calor a partir de las temperaturas medidas con una cámara termográfica. De este modo, no solo se usa la termografía para representar el estado de la pared, sino que también se usan los valores de temperatura contenidos en la termografía para la extracción de parámetros métricos del edificio en estudio, por lo que la hibridación de la información termográfica con el material cartográfico de precisión permitiría extraer la geometría real del objeto de estudio con textura termográfica, pudiendo así realizar mediciones precisas de los elementos de interés directamente sobre el resultado obtenido.

 

20140220-usal-ensmart-panoramica-728

 

Estudios como el publicado por EuroACE en 2010 colocan la mejora de la eficiencia energética en edificación en cabeza de las acciones necesarias para la reducción de emisiones de gases del efecto invernadero y gasto energético, así como para servir de empuje a la generación de empleo. Especial es el caso del parque de edificios ya construidos, la mayoría procedente de los años 1940-80, con normativa inexistente y recursos escasos. En ellos las obras de rehabilitación energética pueden suponer un ahorro de hasta el 75% en consumo de energía. En España existen 13 millones de viviendas susceptibles de intervención, cuya rehabilitación energética supondría una reducción de las emisiones del sector del 34% con respecto al año 2001.

×
Building thermographic analysis

 

 

The use of infraMapaEnergeticored thermography as a widely tested technique for building inspection and location of pathologies such as air leakage and moisture allows the performance of  quality “in-situ” visual examination of the objects under study due to the possibility of obtaining real-time results, being able to detect without difficulty damages or material characteristics. This qualitative measurement technique provides the capability of doing quick, effective and non-destructive inspection without direct contact with the object under study, decreasing the risk of incidents to operators and the damage of the objects comparing with other intrusive techniques. Furthermore, the utility of infrared thermography as a measurement technique has been proved by its use for the determination of the thermophysical properties of materials such as diffusivity and thermal transmittance.

In the qualitative approach, some authors have performed in-situ studies, mainly in historical buildings or cultural heritage elements, whereas quantitative studies are performed mainly in laboratories with limited size samples. In those cases where quantitative thermography studies were performed in-situ, temperature values were employed in order to obtain the real thermophysical properties (thermal conductance) of the building envelope, but their spatial distribution is not considered.

Combine both applications will enable the automation of the heat loss computation from the measured temperatures with a thermographic camera. Thus, the thermography is not only used to represent the state of the wall, but also temperature values represented on the thermography for extracting the metric parameters of the study object so the hybridization of the thermographic information with precise cartographic material would  allow to extract the actual geometry of the object of study with thermal texture, being able to make accurate measurements of the elements of interest directly on the obtained results.

 

20140220-usal-ensmart-panoramica-728

 

Studies such as the one published by EuroACE in 2010, places improved energy efficiency in building construction at the top of the list of actions that need to be taken to reduce greenhouse gases and energy costs, in addition to acting as a stimulus to generate employment. In particular is the case of existing buildings stock, most of which dates back to the period 1940-80, constructed using non-existent standards and scarce resources. Here, energy refurbishment works could represent a saving of up to 75% in energy consumption. In Spain there are 13 million homes that could be the subject of intervention, where energy refurbishment could result in a reduction in sector emissions of 34% compared to 2001.

 

×
×
Ventana modal ingles
×
Ventana modal español
×
Mobile Laser System (MLS) applied to urban tree inventory

In urbanized Western Europe trees are considered an important component of the built-up environment. This also means that there is an increasing demand for tree inventories. Laser mobile mapping systems provide an efficient and accurate way to sample the 3D road surrounding including notable roadside trees. In this research line, a processing chain aiming at the extraction of tree locations and tree sizes from laser mobile mapping data is reached.

  • Vegetation extraction

MLS_urban_3

  • Tree parameter extraction

MLS_urban_2

 

Such steps, in combination with code optimization are expected to be sufficient to reach the final goal of automatized estimation of features sampled by mobile mapping at a rate that matches the acquisition speed and at a quality that matches the result of a human operator.

×