Revista de Teledeteccion最新文献

{"title":"Evaluación de algoritmos de clasificación en la plataforma Google Earth Engine para la identificación y detección de cambios de construcciones rurales y periurbanas a partir de imágenes de alta resolución","authors":"Alejandro Coca-Castro, M. A. Zaraza-Aguilera, Yilsey T. Benavides-Miranda, Yeimy Montilla-Montilla, Heidy B. Posada-Fandiño, Angie L. Avendaño-Gomez, Hernando A. Hernández-Hamon, Sonia C. Garzón-Martinez, Carlos A. Franco-Prieto","doi":"10.4995/RAET.2021.15026","DOIUrl":"https://doi.org/10.4995/RAET.2021.15026","url":null,"abstract":"Building change detection based on remote sensing imagery is a key task for land management and planning e.g., detection of illegal settlements, updating land records and disaster response. Under the post- classification comparison approach, this research aimed to evaluate the feasibility of several classification algorithms to identify and capture buildings and their change between two time steps using very-high resolution images (<1 m/pixel) across rural areas and urban/rural perimeter boundaries. Through an App implemented on the Google Earth Engine (GEE) platform, we selected two study areas in Colombia with different images and input data. In total, eight traditional classification algorithms, three unsupervised (K-means, X-Means y Cascade K-Means) and five supervised (Random Forest, Support Vector Machine, Naive Bayes, GMO maximum Entropy and Minimum distance) available at GEE were trained. Additionally, a deep neural network named Feature Pyramid Networks (FPN) was added and trained using a pre-trained model, EfficientNetB3 model. Three evaluation zones per study area were proposed to quantify the performance of the algorithms through the Intersection over Union (IoU) metric. This metric, with a range between 0 and 1, represents the degree of overlapping between two regions, where the higher agreement the higher IoU values. The results indicate that the models configured with the FPN network have the best performance followed by the traditional supervised algorithms. The performance differences were specific to the study area. For the rural area, the best FPN configuration obtained an IoU averaged for both time steps of 0.4, being this four times higher than the best supervised model, Support Vector Machines using a linear kernel with an average IoU of 0.1. Regarding the setting of urban/rural perimeter boundaries, this difference was less marked, having an average IoU of 0.53 in comparison to 0.38 obtained by the best supervised classification model, in this case Random Forest. The results are relevant for institutions tracking the dynamics of building areas from cloud computing platfo future assessments of classifiers in likewise platforms in other contexts.","PeriodicalId":43626,"journal":{"name":"Revista de Teledeteccion","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45251568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluación de parámetros de segmentación en OBIA para la clasificación de coberturas del suelo a partir de imágenes VANT","authors":"S. I. Hinojosa-Espinoza, José Luis Gallardo-Salazar, Félix J. C. Hinojosa-Espinoza, Anulfo Meléndez-Soto","doi":"10.4995/RAET.2021.14782","DOIUrl":"https://doi.org/10.4995/RAET.2021.14782","url":null,"abstract":"Unmanned Aerial Vehicles (UAVs) have given a new boost to remote sensing and image classification techniques due to the high level of detail among other factors. Object-based image analysis (OBIA) could improve classification accuracy unlike to pixel-based, especially in high-resolution images. OBIA application for image classification consists of three stages i.e., segmentation, class definition and training polygons, and classification. However, defining the parameters: spatial radius (SR), range radius (RR) and minimum region size (MR) is necessary during the segmentation stage. Despite their relevance, they are usually visually adjusted, which leads to a subjective interpretation. Therefore, it is of utmost importance to generate knowledge focused on evaluating combinations of these parameters. This study describes the use of the mean-shift segmentation algorithm followed by Random Forest classifier using Orfeo Toolbox software. It was considered a multispectral orthomosaic derived from UAV to generate a suburban map land cover in town of El Pueblito, Durango, Mexico. The main aim was to evaluate efficiency and segmentation quality of nine parameter combinations previously reported in scientific studies.This in terms of number generated polygons, processing time, discrepancy measures for segmentation and classification accuracy metrics. Results evidenced the importance of calibrating the input parameters in the segmentation algorithms. Best combination was RE=5, RR=7 and TMR=250, with a Kappa index of 0.90 and shortest processing time. On the other hand, RR showed a strong and inversely proportional degree of association regarding the classification accuracy metrics.","PeriodicalId":43626,"journal":{"name":"Revista de Teledeteccion","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46764379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monitoreo de la variación del almacenamiento de agua en la cuenca del Medio y Bajo Paraná a partir de datos GRACE, GRACE FO, TRMM y GLDAS","authors":"Cecilia Cornero, Ayelen Pereira, Ana Cristina Oliveira Cancoro de Matos, María Cristina Pacino, Denizar Blitzkow","doi":"10.4995/RAET.2021.15211","DOIUrl":"https://doi.org/10.4995/RAET.2021.15211","url":null,"abstract":"GRACE (Gravity Recovery and Climate Experiment) is a satellite mission that can monitor mass distributions in the Earth system, which is closely related to the consequences of climate change. This gravimetric satellite allows to obtain monthly variations of the Earth’s gravity field, which can be associated with water mass variations, after removing the effects of oceanic tides and solid Earth, as well as non-tidal oceanic and atmospheric contributions. In this work, data from GRACE (2002-2017) and GRACE FO (since 2018) were used to analyze the variation of the water mass in the Middle and Low Paraná river basin. The interpretation of the results was carried out by associating the mass anomalies derived from GRACE data with information from the TRMM global rainfall mission. Monthly maps of GRACE water mass variations and TRMM precipitation were produced, which made possible a thorough analysis at a regional level of this mass redistribution in the basin, and its connection to the El Niño and La Niña events that took place in the period under study. The water deficits shown in the 2009 GRACE maps are, in fact, related to the intense episode of La Niña that occurred in the period 2008-2009; while the excess of water storage depicted on the 2016 and 2019 maps is connected to the El Niño phenomenon. Moreover, GRACE has also detected drought events in different sectors between 2011-2012, together with floods in the years 2007 and 2010. Monthly GRACE-derived water storage changes were compared with the independent components of the water balance in the region using different hydrological models estimates. Finally, the temporal variations of the groundwater and the soil part (surface water, soil moisture) were analyzed using the Global Land Data Assimilation System GLDAS. The variables showed a good correlation between them, reaching values of ~r = 0.80.","PeriodicalId":43626,"journal":{"name":"Revista de Teledeteccion","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44535220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aplicación de una metodología simplificada para estimar las curvas de capacidad de embalses","authors":"S. A. Ochoa-García","doi":"10.4995/RAET.2021.15303","DOIUrl":"https://doi.org/10.4995/RAET.2021.15303","url":null,"abstract":"In the management of the regulation volumes of the water resource projected for a variety of benefits (hydroelectric uses, irrigation, drinking water, among others), it is essential to calculate the morphometric variables of the reservoirs to anticipate changes in their morphology and predict how these changes could affect projected achievement. In this document, taking into consideration the fundamental concepts of Integral Calculus, the development of an innovative methodology is presented to obtain the Cota-Volume and Cota-Area curves in reservoirs; the methodology was formulated in R programming language with the help of geographic information tools. A computational optimization was achieved for the processing of the variables of level, area and volume of a regulation body respect to the use of traditional methodologies. To validate the developed tool, the capacity curves of regulation volume of the Minas - San Francisco reservoir located in the south of the Republic of Ecuador were obtained. This reservoir was designed to dislodge its sediments with washing processes. This fact has motivated the continuous monitoring of the morphological conditions of the reservoir to plan maintenance processes due to the loss of volume and to the deposit of particles from its tributaries. In addition, an analysis based on wavelets curves was applied to the digital elevation models obtained from LiDAR techniques and bathymetric echo sounder to demonstrate the sedimentation processes that occur in this body of regulation.","PeriodicalId":43626,"journal":{"name":"Revista de Teledeteccion","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48325534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cartografía de la afección y recuperación vegetal del incendio de Las Peñuelas en Moguer (Huelva) con imágenes satelitales. Año 2017","authors":"J. J. Vales, I. Pino, L. Granado, R. Prieto, E. Méndez, M. Rodríguez, F. Giménez de Azcárate, E. Ortega, J. M. Moreira","doi":"10.4995/raet.2020.13082","DOIUrl":"https://doi.org/10.4995/raet.2020.13082","url":null,"abstract":"Deep knowledge of the regeneration processes after a forest fire is key to addressing their adverse environmental impacts, these are especially evident in the vegetation. In the post-fire environment context, the fire severity constitutes a critical variable that affects the ecosystem response in terms of vegetation recovery and hydrogeomorphological dynamics after the fire. Therefore, the severity accurate assessment is essential for the burned areas management because of it allows the identification of priority areas and, therefore, it helps to carry out recovery strategies and measures. The area of interest is located in the natural place of Las Peñuelas (Huelva), where a large fire took place on June 24, 2017 that affected almost 10 000 ha. The methodology was based on the calculation of the RBR (Relativized Burn Ratio) spectral index to estimate the severity of the fire, and the NDVI (Normalized Difference Vegetation Index) index to evaluate the recovery of vegetal vigor. For the work, images from the Sentinel-2 and Pleiades satellites, images acquired by UAV (Unmanned Aerial Vehicle) and field samplings were used. The result was a cartography showing the levels of recovery or degradation of the affected vegetation.","PeriodicalId":43626,"journal":{"name":"Revista de Teledeteccion","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2020-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70599223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimación de la fenología de la vegetación a partir de imágenes de satélite: el caso de la península ibérica e islas Baleares (2001-2017)","authors":"Jose A. Caparros-Santiago, V. Rodriguez-Galiano","doi":"10.4995/raet.2020.13632","DOIUrl":"https://doi.org/10.4995/raet.2020.13632","url":null,"abstract":"Phenological dynamics of vegetation is considered as an important biological indicator for understanding the functioning of terrestrial ecosystems. Land surface phenology (LSP), the study of vegetation phenology from time series of vegetation indices (IV), has provided a comprehensive overview of ecosystem dynamics. Iberian Peninsula is one of the regions with the greatest diversity of ecosystems in European continent. It is therefore an excellent study area for monitoring phenological dynamics of vegetation. The aim of this study is to analyse the spatial variability of the phenology of the vegetation of the Iberian Peninsula and Balearic Islands for the period 2001-2017. NDVI (Normalized Difference Vegetation Index) time series were generated from the surface reflectance product MOD09Q1 at a spatial resolution of 250 meters and with a composite period of 8 days. Atmospheric disturbances and noise were reduced using a Savitzky-Golay smoothing filter. Different phenological metrics or phenometrics were extracted using a threshold-based method. Results showed the existence of a different behaviour between spring and autumn phenophases in the Atlantic and Mediterranean biogeographic regions. The Mediterranean mountainous areas showed a similar phenological behaviour to the Atlantic vegetation. Biogeographic regions showed an internal variability, which may be derived from the different behaviour of land covers (e.g., natural vegetation vs. crops).","PeriodicalId":43626,"journal":{"name":"Revista de Teledeteccion","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2020-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46245353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial and temporal analysis of surface temperature in the Apacheta micro-basin using Landsat thermal data","authors":"W. Moncada, B. Willems","doi":"10.4995/raet.2020.13855","DOIUrl":"https://doi.org/10.4995/raet.2020.13855","url":null,"abstract":"High Andean ecosystems, such as grasslands and peatlands, are fragile and, due to the effects of climate change, their sustainability is being jeopardized. A key factor hampering sustainable management efforts from the government and communities, is the lack or scarcity of in-situ eco-hydrological and climate data. In that sense, remote sensing techniques offers a powerful alternative for the assessment of the evolution of these ecosystems, by providing a holistic view of the territory. The objective of this work is to determine both the spatial and temporal evolution of the local atmospheric temperature of the Apacheta micro-basin in Ayacucho over the past 34 years, using the soil surface temperature (SST) as a proxy. For this, thermal data of Landsat series (TM, ETM+ and TIRS sensors), covering the period from 1985 to 2018, were used. The TSS estimates were made from the emissivity correction of the brightness temperatures at the top of the atmosphere, considering the negligible atmospheric effect due to the conditions of high atmospheric transmissivity in the study area. The results show a positive trend of the SST with an increase of 4.9 °C, equivalent to 27.5% of the SST. Trends are higher (5.8 °C) in the snowy areas (equivalent to 35.3% of the TSS in the whole micro-basin). The SST in the snow area explains the 83.6% of the behavior of the snow cover derived by the NDSI, with a decreasing surface as SST increase.","PeriodicalId":43626,"journal":{"name":"Revista de Teledeteccion","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2020-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42116715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluación de cuatro algoritmos de clasificación de imágenes satelitales Landsat-8 y Sentinel-2 para la identificación de cobertura boscosa en paisajes altamente fragmentados en Costa Rica","authors":"I.D. Ávila-Pérez, E. Ortiz-Malavassi, C. Soto-Montoya, Y. Vargas-Solano, H. Aguilar-Arias, C. Miller-Granados","doi":"10.4995/raet.2020.13340","DOIUrl":"https://doi.org/10.4995/raet.2020.13340","url":null,"abstract":"Mapping of land use and forest cover and assessing their changes is essential in the design of strategies to manage and preserve the natural resources of a country, and remote sensing have been extensively used with this purpose. By comparing four classification algorithms and two types of satellite images, the objective of the research was to identify the type of algorithm and satellite image that allows higher global accuracy in the identification of forest cover in highly fragmented landscapes. The study included a treatment arrangement with three factors and six randomly selected blocks within the Huetar Norte Zone in Costa Rica. More accurate results were obtained for classifications based on Sentinel-2 images compared to Landsat-8 images. The best classification algorithms were Maximum Likelihood, Support Vector Machine or Neural Networks, and they yield better results than Minimum Distance Classification. There was no interaction among image type and classification methods, therefore, Sentinel-2 images can be used with any of the three best algorithms, but the best result was the combination of Sentinel-2 and Support Vector Machine. An additional factor included in the study was the image acquisition date. There were significant differences among months during which the image was acquired and an interaction between the classification algorithm and this factor was detected. The best results correspond to images obtained in April, and the lower to September, month that corresponds with the period of higher rainfall in the region studied. The higher global accuracy identifying forest cover is obtained with Sentinel-2 images from the dry season in combination with Maximum Likelihood, Support Vector Machine, and Neural Network image classification methods.","PeriodicalId":43626,"journal":{"name":"Revista de Teledeteccion","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2020-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70598956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of OMI-DOAS total ozone column with ground-based measurements in Argentina","authors":"P. F. Orte, E. Luccini, E. Wolfram, F. Nollas, J. Pallotta, R. D’Elia, G. Carbajal, N. Mbatha, N. Hlongwane","doi":"10.4995/raet.2020.13673","DOIUrl":"https://doi.org/10.4995/raet.2020.13673","url":null,"abstract":"Total ozone column (TOC) measurements through the Ozone Monitoring Instrument (OMI/NASA EOSAura) are compared with ground-based observations made using Dobson and SAOZ instruments for the period 2004–2019 and 2008–02/2020, respectively. The OMI data were inverted using the Differential Optical Absorption Spectroscopy algorithm (overpass OMI-DOAS). The four ground-based sites used for the analysis are located in subpolar and subtropical latitudes spanning from 34°S to 54°S in the Southern Hemisphere, in the Argentine cities of Buenos Aires (34.58°S, 58.36°W; 25 m a.s.l.), Comodoro Rivadavia (45.86°S, 67.50°W; 46 m a.s.l.), Río Gallegos (51.60°S, 69.30°W; 72 m a.s.l.) and Ushuaia (54.80°S, 68.30°W; 14 m a.s.l.). The linear regression analyzes showed correlation values greater than 0.90 for all sites. The OMI measurements revealed an overestimation of less than 4 % with respect to the Dobson instruments, while the comparison with the SAOZ instrument presented a very low underestimation of less than 1 %.","PeriodicalId":43626,"journal":{"name":"Revista de Teledeteccion","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2020-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70599010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Conectividad estructural entre los Páramos de Guacheneque y Los Cristales, complejo Rabanal-río Bogotá, Colombia","authors":"Y. K. Forero-Gómez, P. Gil-Leguizamón, M. E. Morales-Puentes","doi":"10.4995/raet.2020.13946","DOIUrl":"https://doi.org/10.4995/raet.2020.13946","url":null,"abstract":"Structural connectivity is a measure of the spatio-temporal changes that affect the movement of species between elements of the landscape and availability of habitat; these modifications that have been documented for high mountain ecosystems in Colombia (páramo and high Andean forest) and are caused by agricultural and other economic activities that affect their integrity. The objective of this study was to evaluate the dynamics of the changes between plant cover (1987-2018) in the Guacheneque and Los Cristales páramos (Boyacá-Cundinamarca, Colombia). Images from Landsat 4 and 8 sensors were used. Pre and post-processing (supervised classification and field verification) were performed with ArcGIS and ERDAS. To estimate structural connectivity, metrics of landscape diversity, composition and configuration were calculated (Fragstats v4.2.1). Thematic reliability was 88%. Mosaic covering of pastures and crops (Mpc – 288 ha), dense grassland of firm ground (HdTf- 24 ha) and high open forest (Baa-165 ha), increased in 31 years, while dense bush (Ad) decreased 477 ha. The distance between tiles of Mpc and Ad increased (from 150.74 m to 170.70 m and from 196.96 m to 236.64 m respectively), and decreased for Baa (from 166.74 m to 159.27 m). Connectivity increased for Mpc and Baa, and decreased for Ad. The evaluated páramos make up a landscape with frequent and intensive land use, the effect of a long history of occupation of this territory. The dynamics of structural connectivity registered an increase in agricultural activities (páramo-grasslands transition). These have caused tensions and contradictions in the delimitation of páramos, a local loss of the natural area, a decrease in the average size of the tiles, and an increase in the perimeter /surface ratio distance between nuclei. The results corroborate the isolation and loss of habitat, the negative impacts on the biodiversity of the Rabanal-Río Bogotá páramos complex.","PeriodicalId":43626,"journal":{"name":"Revista de Teledeteccion","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2020-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47708356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}