Ailin Sol Ortone Lois | Universidad Tecnológica Nacional (original) (raw)
Papers by Ailin Sol Ortone Lois
Journal of South American earth sciences, Jun 1, 2024
Simple stacking of InSAR Digital Elevation Models (DEMs) has shown potential to increase DEM qual... more Simple stacking of InSAR Digital Elevation Models (DEMs) has shown potential to increase DEM quality. In order to obtain a straight-forward stacking procedure that reduces the uncertainty of InSAR DEMs, in this contribution we evaluate in detail the impact of different stacking routines on the accuracy of stacked DEMs. For that end, we performed systematic tests in a region of Cordoba, ´ Argentina. First, we produced a set of 54 Sentinel-1 and 10 SAOCOM-1 InSAR DEMs, which were evaluated with respect to a reference photogrammetric DEM. We then tested different stacking workflows, obtaining stacked DEMs with a higher average accuracy than that of the single-pair DEMs. This suggests that the uncertainty in the quality of the InSAR DEMs can be overcome by simple stacking techniques. Further post-processing of the stacked DEMs involved planimetric position correction by co- registration with the reference DEM, altimetric correction by linear regression adjustment to the national alti- metric network, and multidirectional filtering to correct for speckling and outliers. The evaluation of the final stacked DEMs with respect to the reference shows that the SAOCOM-1 stacked DEM has a mean biased error of 0.39 m with a standard deviation of 3.77 m, whereas the Sentinel-1 stacked DEM has a mean biased error of 2.25 m with a standard deviation of 7.61 m. Both DEMs offered a smaller pixel size (15 m) than the available Argentine digital elevation model MDE-Ar (30 m), but with a lower accuracy. In turn, the combination of the SAOCOM-1 and Sentinel-1 stacked DEMs resulted in a 50 % and 33 % reduction in the mean biased error and the standard deviation, respectively, with respect to the SAOCOM-1 stacked DEM; an accuracy close to that of MDE- Ar, with a smaller pixel size. Although further improvements could be accomplished by exploring more so- phisticated stacking and data-fusion techniques, these results constitute a significant step towards the system- atization of a methodology to obtain reliable DEMs from SAR data.
Journal of South American Earth Sciences, 2024
Simple stacking of InSAR Digital Elevation Models (DEMs) has shown potential to increase DEM qual... more Simple stacking of InSAR Digital Elevation Models (DEMs) has shown potential to increase DEM quality. In order
to obtain a straight-forward stacking procedure that reduces the uncertainty of InSAR DEMs, in this contribution
we evaluate in detail the impact of different stacking routines on the accuracy of stacked DEMs. For that end, we
performed systematic tests in a region of Cordoba, ´ Argentina. First, we produced a set of 54 Sentinel-1 and 10
SAOCOM-1 InSAR DEMs, which were evaluated with respect to a reference photogrammetric DEM. We then
tested different stacking workflows, obtaining stacked DEMs with a higher average accuracy than that of the
single-pair DEMs. This suggests that the uncertainty in the quality of the InSAR DEMs can be overcome by simple
stacking techniques. Further post-processing of the stacked DEMs involved planimetric position correction by co-
registration with the reference DEM, altimetric correction by linear regression adjustment to the national alti-
metric network, and multidirectional filtering to correct for speckling and outliers. The evaluation of the final
stacked DEMs with respect to the reference shows that the SAOCOM-1 stacked DEM has a mean biased error of
0.39 m with a standard deviation of 3.77 m, whereas the Sentinel-1 stacked DEM has a mean biased error of 2.25
m with a standard deviation of 7.61 m. Both DEMs offered a smaller pixel size (15 m) than the available
Argentine digital elevation model MDE-Ar (30 m), but with a lower accuracy. In turn, the combination of the
SAOCOM-1 and Sentinel-1 stacked DEMs resulted in a 50 % and 33 % reduction in the mean biased error and the
standard deviation, respectively, with respect to the SAOCOM-1 stacked DEM; an accuracy close to that of MDE-
Ar, with a smaller pixel size. Although further improvements could be accomplished by exploring more so-
phisticated stacking and data-fusion techniques, these results constitute a significant step towards the system-
atization of a methodology to obtain reliable DEMs from SAR data.
Congreso Argentino de Cartografía, 2022
El Campo de Hielo Patagónico (CHP) de 20100 km2 de superficie, es el área glaciaria más extensa c... more El Campo de Hielo Patagónico (CHP) de 20100 km2 de superficie, es el área glaciaria más extensa con excepción de la Antártida y Groenlandia. Se extiende en dirección norte-sur entre los paralelos 46° y 51° 30’, abarcando desde el Pacífico hasta los grandes lagos patagónicos australes. Se divide en dos sectores, el Campo de Hielo Patagónico Norte y Sur (CHPN y CHPS), que comprenden una gran cantidad de glaciares distribuidos en 48 cuencas. El área de estudio propiamente dicha abarca un pequeño sector del Parque Nacional Los Glaciares compuesto por los glaciares Frías, Cubo y Dickson, el cual es parte del CHPS. El objetivo del trabajo fue el desarrollo de Modelos Digitales de Elevación (DEMs) mediante la aplicación de técnicas de Interferometría de Radar de Apertura Sintética (InSAR) y su comparación con otros modelos existentes disponibles gratuitamente. En el monitoreo de glaciares, los DEMs pueden ser utilizados para determinar el balance de masas, mediante la comparación de alturas en distintos puntos de las zonas de ablación y acumulación del glaciar a través del tiempo. Esta metodología puede utilizarse complementariamente a otros métodos de balance de masas como el hidrológico o glaciológico, y es muy útil en zonas de difícil acceso como es el área de estudio. El monitoreo de glaciares es esencial para estimar cambios en su morfología, así como también comprender su comportamiento no solo en el presente sino a futuro.
Revista Cartográfica, 2021
El presente estudio contempla un análisis multitemporal con imágenes satelitales y datos meteorol... more El presente estudio contempla un análisis multitemporal con imágenes satelitales y datos meteorológicos de un grupo de glaciares denominados Glaciares Escondidos, ubicados al suroeste del Campo de Hielo Patagónico Sur. Compuesto por los glaciares Dickson, Cubo y Frías, este ha sufrido un marcado retroceso de sus frentes que se aceleró en los últimos 10 años. La alimentación de los glaciares Dickson y Frías se hacía originalmente por una sola corriente de hielo y solían actuar como diques naturales, evitando el flujo del agua entre el Lago Frías y el Lago Dickson. Debido a la pérdida de masa y el retroceso de sus frentes, las aguas que recorrían más de 250 km atravesando por completo la árida llanura de la Patagonia para desembocar en el Océano Atlántico, hoy lo hacen hacia el Océano Pacífico navegando las aguas de los fiordos chilenos que fluyen hacia el oeste. Se observan formaciones de lagos proglaciarios, un aumento en la velocidad de retroceso y una elevada velocidad de flujo d...
Este documento no es un paper, forma parte de un proyecto para cálculos de balance de masas sobre... more Este documento no es un paper, forma parte de un proyecto para cálculos de balance de masas sobre dos glaciares de la Patagonia, utilizando DEMs propios generados por técnicas de InSAR
Fil: Gari, Jorge Marcelo. Universidad Tecnologica Nacional. Facultad Regional Haedo; Argentina
Fil: Gari, Jorge Marcelo. Universidad Tecnologica Nacional. Facultad Regional Haedo; Argentina.
El presente estudio contempla un análisis multitemporal con imágenes satelitales y datos meteorol... more El presente estudio contempla un análisis multitemporal con imágenes satelitales y datos meteorológicos de un grupo de glaciares denominados Glaciares Escondidos, ubicados al suroeste del Campo de Hielo Patagónico Sur. Compuesto por los glaciares Dickson, Cubo o
Gorra y Frías, ha sufrido un marcado retroceso de sus frentes que se aceleró en los últimos 35 años. La alimentación de los glaciares Dickson y Frías se hacía originalmente por una sola corriente de hielo y solían actuar como diques naturales, evitando el flujo del agua entre el Lago
Frías y el Lago Dickson. Debido a la pérdida de masa y el retroceso de sus frentes, las aguas que recorrían más de 250 km atravesando por completo la árida llanura de la Patagonia para desembocar en el Océano Atlántico, hoy lo hacen hacia el Océano Pacífico navegando las aguas
de los fiordos chilenos que fluyen hacia el oeste. Se observan formaciones de lagos proglaciarios, un aumento en la velocidad de retroceso y una elevada velocidad de flujo del hielo, las cuales fueron estimadas con mediciones multitemporales y la técnica de offset tracking con imágenes radar. Asimismo, se presentan análisis de balances de masa sobre estos tres glaciares de los últimos 20 años, utilizando el método geodésico.
There has been a marked retreat of the glaciers located to the southwest of the Southern Patagoni... more There has been a marked retreat of the glaciers located to the southwest of the Southern Patagonian Ice Field, called Glaciares Escondidos (Hidden in english), especially in the last 35 years. The continental basin that divides Pacific and Atlantic oceans is currently located in these glaciers. Indeed, Dickson and Frías glaciers were originally fed by a single stream of ice. Starting at Cerro Cubo, the waters traveled the more than 250 km necessary to completely cross the arid plain of Patagonia,
and finally flow into the Atlantic Ocean. This paper presents a multitemporal study with remote sensing images from Landsat and Sentinel sensors, both medium spatial resolutions. Successively, we monitor their dynamics, observing formations of proglacial lakes, accumulation of sediments and movement of moraines, providing conclusions related to the water basin. Likewise, we estimated surface ice speeds on these glaciers using multitemporal measurements and offset tracking technique, based on satellite radar images. This area was selected because we observed great retreat in previous studies, which becomes more prominent since the 80s. It is worth mentioning that there has not been much research on this group of glaciers in the country.
The aim of this work consists in the delineation of the highest points of the Southern Patagonian... more The aim of this work consists in the delineation of the highest points of the Southern Patagonian Ice Field located between the parallels 48 ° 20 'of latitude S up to 51 ° 30' of latitude S, using satellite data from digital models of elevation and optical images and radar.
The Southern Patagonian Ice Field is the third largest continental ice supply in the world after Antarctica and Greenland, and is located in the southwest of the province of Santa Cruz, near the town of El Calafate. Los Glaciares National Park is one of the study areas found in this work, and cover part of this field. A digital elevation model or DEM according to its acronym in English, describes the topography of the terrain through bounded points defined as a triple composed of a value of altitude z defined at sea level, and their corresponding values of coordinates x and y, distributed in homogeneous shape on the earth's surface.
The DEMs were obtained from the data supplied by the SAR PALSAR sensor on the ALOS satellite (Advanced Earth Observation Satellite).
The structure of this height data is represented vectorially as well as raster, according to its source. They are extremely important to survey topographic and hydrographic networks, determine heights in
mountain areas and highlands as this case, as well as to perform slope calculations and contours that can be used in observations of landslides in the ice field and glaciers of hillside. Likewise, optical satellite were used to recognize the terrain and its representation in three-dimensional form, in order to achieve a better visualization of the topography and relief of the area. With this study we only intend to give an approximation for future cartographic representations carried out by official organisms.
This paper reviews a remote sensing method for estimating mass balance of Upsala Glacier. This gl... more This paper reviews a remote sensing method for estimating mass balance of Upsala Glacier. This glacier is located in Los Glaciares National Park, Santa Cruz, in Patagonia and it is the second largest glacier in Argentina, though it has exhibited dramatic retreats in the last years. A former methodology used in Viedma glacier was improved, determining characteristics of the glacier such as ice extent, terminus position, the Snow Line Altitude (SLA) in different dates, the relationship with the Equilibrium Line (ELA) and estimation of volume changes in a specific period of time. From this method, the change in local mass balance can be inferred according to ice and snow flow in a cycle. In absence of direct measurements, we apply remote sensing methods used in previous investigations. For this, we use optical Landsat 5-TM and Landsat 8-
OLI images, digital elevation models ASTER GDEM V2 and SRTM Mission (Shuttle Radar Topography Mission), both with a 30 m. pixel size, and topographic charts. Mass balance measurements were analyzed taking into account temperature and rainfall data from many sources, establishing a relationship among them and glacial retreat over a specified period of time. At the same time, public and free GIS database (provided by Instituto Geográfico Nacional in Argentina) was embedded in a geographic data system, consisting of vector layers with altitude information, dimensional points, contour lines and feature tables of the glaciers within the area of interest.
RESUMEN La utilización de imágenes satelitales permite recolectar información en sitios remotos, ... more RESUMEN La utilización de imágenes satelitales permite recolectar información en sitios remotos, abarcando una gran superficie de análisis y monitoreando visualmente áreas de difícil acceso, lo cual implicaría un gran costo tanto en tiempo como de recursos económicos. Esto es importante en una zona como la del Parque Nacional Los Glaciares en la provincia de Santa Cruz, donde se ubica el glaciar Viedma. A pesar de ser el mayor en tamaño del Parque Nacional, este glaciar ha sido muy poco estudiado, por lo que resulta esencial realizar algunas aproximaciones en materia de reconocimiento de su morfología y comportamiento, ya que ocupa una región de importancia natural, hídrica y paisajística. En el presente trabajo se buscó probar metodologías de estudio y clasificación de estructuras de hielo en el Glaciar Viedma combinando imágenes ópticas y de radar. Se estudió la capacidad de la imagen radar de la misión Sentinel 1A de la ESA (European Space Agency: Agencia Espacial Europea) en combinación con una imagen óptica del satélite SPOT 5 (Satellite Pour l'Observation de la Terre: Satélite Para la Observación de la Tierra), a partir de técnicas de procesamiento digitales que integran la información de ambas imágenes. Se destaca la importancia del uso de la tecnología radar como una ayuda invalorable para el estudio de zonas con características climáticas típicas de la Cordillera Patagónica, donde la mayor parte del tiempo se encuentra cubierto de nubes. Se evaluó de esta forma el aporte que ofrecen ambos sensores para definir y caracterizar los tipos de hielo y sus combinaciones con detritos rocosos, agua y nieve, que puede encontrarse en un glaciar de estas magnitudes, generando una cartografía temática de las unidades identificadas. ABSTRACT Remote sensing approaches allow for regular monitoring in remote areas, with large coverage. The increased availability of imagery from these platforms allows extending the measurements of hardly accessible terrains, with low financial costs and longer time spans. This is of main interest in Parque Nacional Los Glaciares in Santa Cruz, where Viedma glacier is placed. Despite it is the greatest glacier in the National Park, it has been slightly investigated, consequently it is of paramount importance to start some approaches regarding its morphology and behavior, since it is located in a natural and enchanting scenery and it is hydric resource. In the following, we present the methodology for classifying ice structures in Viedma glacier working with optical and radar imagery. The capability of the combination of ESA Sentinel 1A radar image and SPOT 5 (Satellite Pour l'Observation de la Terre) optical image was studied. For this, digital processing techniques where applied, incorporating information from both images. We emphasize the importance of radar technology as a valuable support for the monitoring of landscapes with unstable weather, as typical in the Patagonian Cordillera, where most of the time the meteorological condition is cloudy. The contribution of both sensors was evaluated in order to define and characterize different sorts of ice, also combined with soil debris, water and snow, found in such glacier. As a result, we obtained a thematic map with the identified classes.
Conference Presentations by Ailin Sol Ortone Lois
Dinámica del movimiento en los Glaciares Escondidos del Campo de Hielo Patagónico Sur, 2020
There has been a marked retreat of the glaciers located to the southwest of the Southern Patagoni... more There has been a marked retreat of the glaciers located to the southwest of the Southern Patagonian Ice Field, called Glaciares Escondidos (Hidden in english), especially in the last 35 years. The continental basin that divides Pacific and Atlantic oceans is currently located in these glaciers. Indeed, Dickson and Frías glaciers were originally fed by a single stream of ice. Starting at Cerro Cubo, the waters traveled the more than 250 km necessary to completely cross the arid plain of Patagonia,
and finally flow into the Atlantic Ocean. This paper presents a multitemporal study with remote sensing images from Landsat and Sentinel sensors, both medium spatial resolutions. Successively, we monitor their dynamics, observing formations of proglacial lakes, accumulation of sediments and movement of moraines, providing conclusions related to the water basin. Likewise, we estimated surface ice speeds on these glaciers using multitemporal measurements and offset tracking technique, based on satellite radar images. This area was selected because we observed great retreat in previous studies, which becomes more prominent since the 80s. It is worth mentioning that there has not been much research on this group of glaciers in the country.
Representación topográfica mediante imágenes satelitales sobre el campo de hielo patagónico sur, 2019
The aim of this work consists in the delineation of the highest points of the Southern Patagonian... more The aim of this work consists in the delineation of the highest points of the Southern Patagonian Ice Field located between the parallels 48 ° 20 'of latitude S up to 51 ° 30' of latitude S, using satellite data from digital models of elevation and optical images and radar.
The Southern Patagonian Ice Field is the third largest continental ice supply in the world after Antarctica and Greenland, and is located in the southwest of the province of Santa Cruz, near the town of El Calafate. Los Glaciares National Park is one of the study areas found in this work, and cover part of this field.
A digital elevation model or DEM according to its acronym in English, describes the topography of the terrain through bounded points defined as a triple composed of a value of altitude z defined at sea level, and their corresponding values of coordinates x and y, distributed in homogeneous shape on the earth's surface.
The DEMs were obtained from the data supplied by the SAR PALSAR sensor on the ALOS satellite (Advanced Earth Observation Satellite).
The structure of this height data is represented vectorially as well as raster, according to its source. They are extremely important to survey topographic and hydrographic networks, determine heights in mountain areas and highlands as this case, as well as to perform slope calculations and contours that can be used in observations of landslides in the ice field and glaciers of hillside. Likewise, optical satellite were used to recognize the terrain and its representation in three-dimensional form, in order to achieve a better visualization of the topography and relief of the area.
With this study we only intend to give an approximation for future cartographic representations carried out by official organisms.
Estimación de la velocidad de desplazamiento del hielo en el Glaciar Upsala mediante imágenes SAR, 2018
The main objective of this work is the estimation of the speed ice flow on the Upsala Glacier usi... more The main objective of this work is the estimation of the speed ice flow on the Upsala Glacier using radar images. The Upsala Glacier is one of the temperate glaciers of high scientific interest in the Southern Patagonian Ice Field that presents a combination of processes and mechanisms such as rapid frontal recession, surface speed variations, changes in mass balance and ablation rates, as well as loss of thickness and high averages of calving, which make it a highly active glacier especially since 1970 onwards being for this reason chosen as a glacier model of the Southern Ice Field. The capacity of the module for radar processing of ESA's SNAP software was investigated in a similar way, particularly the technique of offset tracking in glaciers. Two radar images of the SAR Sentinel 1-A satellite were processed with a difference of 12 days of acquisition, obtaining ice speed maps during the study period. At the same time, the retreat data of the glacier investigated with optical images was updated since 1981.
El objetivo principal de este trabajo es la estimación de la velocidad del flujo de hielo sobre el glaciar Upsala utilizando imágenes radar. El glaciar Upsala es uno de los glaciares temperados de alto interés científico en el Campo de Hielo Patagónico Sur que presenta una combinación de procesos y mecanismos tales como retroceso frontal rápido, variaciones de la velocidad superficial, cambios en el balance de masa y tasas de ablación, así como pérdida de espesor y altos promedios de calving, lo que lo convierten en un glaciar altamente activo en especial desde 1970 en adelante siendo por esta razón elegido como modelo de glaciar del Campo de Hielo Sur. De igual manera, se investigó la capacidad del módulo para procesamiento radar del software SNAP de la ESA, particularmente la técnica de offset tracking en glaciares. Se procesaron dos imágenes radar del satélite SAR Sentinel 1-A con diferencia de 12 días de adquisición, obteniendo mapas de velocidad de hielo durante el período de estudio. Paralelamente, se actualizaron los datos de retroceso del glaciar investigado con imágenes ópticas desde el año 1981. Palabras clave: Glaciar Upsala-Offset tracking-Sentinel-Velocidad de hielo
Drafts by Ailin Sol Ortone Lois
Este documento no es un paper, forma parte de un proyecto para cálculos de balance de masas sobre... more Este documento no es un paper, forma parte de un proyecto para cálculos de balance de masas sobre dos glaciares de la Patagonia, utilizando DEMs propios generados por técnicas de InSAR
Journal of South American earth sciences, Jun 1, 2024
Simple stacking of InSAR Digital Elevation Models (DEMs) has shown potential to increase DEM qual... more Simple stacking of InSAR Digital Elevation Models (DEMs) has shown potential to increase DEM quality. In order to obtain a straight-forward stacking procedure that reduces the uncertainty of InSAR DEMs, in this contribution we evaluate in detail the impact of different stacking routines on the accuracy of stacked DEMs. For that end, we performed systematic tests in a region of Cordoba, ´ Argentina. First, we produced a set of 54 Sentinel-1 and 10 SAOCOM-1 InSAR DEMs, which were evaluated with respect to a reference photogrammetric DEM. We then tested different stacking workflows, obtaining stacked DEMs with a higher average accuracy than that of the single-pair DEMs. This suggests that the uncertainty in the quality of the InSAR DEMs can be overcome by simple stacking techniques. Further post-processing of the stacked DEMs involved planimetric position correction by co- registration with the reference DEM, altimetric correction by linear regression adjustment to the national alti- metric network, and multidirectional filtering to correct for speckling and outliers. The evaluation of the final stacked DEMs with respect to the reference shows that the SAOCOM-1 stacked DEM has a mean biased error of 0.39 m with a standard deviation of 3.77 m, whereas the Sentinel-1 stacked DEM has a mean biased error of 2.25 m with a standard deviation of 7.61 m. Both DEMs offered a smaller pixel size (15 m) than the available Argentine digital elevation model MDE-Ar (30 m), but with a lower accuracy. In turn, the combination of the SAOCOM-1 and Sentinel-1 stacked DEMs resulted in a 50 % and 33 % reduction in the mean biased error and the standard deviation, respectively, with respect to the SAOCOM-1 stacked DEM; an accuracy close to that of MDE- Ar, with a smaller pixel size. Although further improvements could be accomplished by exploring more so- phisticated stacking and data-fusion techniques, these results constitute a significant step towards the system- atization of a methodology to obtain reliable DEMs from SAR data.
Journal of South American Earth Sciences, 2024
Simple stacking of InSAR Digital Elevation Models (DEMs) has shown potential to increase DEM qual... more Simple stacking of InSAR Digital Elevation Models (DEMs) has shown potential to increase DEM quality. In order
to obtain a straight-forward stacking procedure that reduces the uncertainty of InSAR DEMs, in this contribution
we evaluate in detail the impact of different stacking routines on the accuracy of stacked DEMs. For that end, we
performed systematic tests in a region of Cordoba, ´ Argentina. First, we produced a set of 54 Sentinel-1 and 10
SAOCOM-1 InSAR DEMs, which were evaluated with respect to a reference photogrammetric DEM. We then
tested different stacking workflows, obtaining stacked DEMs with a higher average accuracy than that of the
single-pair DEMs. This suggests that the uncertainty in the quality of the InSAR DEMs can be overcome by simple
stacking techniques. Further post-processing of the stacked DEMs involved planimetric position correction by co-
registration with the reference DEM, altimetric correction by linear regression adjustment to the national alti-
metric network, and multidirectional filtering to correct for speckling and outliers. The evaluation of the final
stacked DEMs with respect to the reference shows that the SAOCOM-1 stacked DEM has a mean biased error of
0.39 m with a standard deviation of 3.77 m, whereas the Sentinel-1 stacked DEM has a mean biased error of 2.25
m with a standard deviation of 7.61 m. Both DEMs offered a smaller pixel size (15 m) than the available
Argentine digital elevation model MDE-Ar (30 m), but with a lower accuracy. In turn, the combination of the
SAOCOM-1 and Sentinel-1 stacked DEMs resulted in a 50 % and 33 % reduction in the mean biased error and the
standard deviation, respectively, with respect to the SAOCOM-1 stacked DEM; an accuracy close to that of MDE-
Ar, with a smaller pixel size. Although further improvements could be accomplished by exploring more so-
phisticated stacking and data-fusion techniques, these results constitute a significant step towards the system-
atization of a methodology to obtain reliable DEMs from SAR data.
Congreso Argentino de Cartografía, 2022
El Campo de Hielo Patagónico (CHP) de 20100 km2 de superficie, es el área glaciaria más extensa c... more El Campo de Hielo Patagónico (CHP) de 20100 km2 de superficie, es el área glaciaria más extensa con excepción de la Antártida y Groenlandia. Se extiende en dirección norte-sur entre los paralelos 46° y 51° 30’, abarcando desde el Pacífico hasta los grandes lagos patagónicos australes. Se divide en dos sectores, el Campo de Hielo Patagónico Norte y Sur (CHPN y CHPS), que comprenden una gran cantidad de glaciares distribuidos en 48 cuencas. El área de estudio propiamente dicha abarca un pequeño sector del Parque Nacional Los Glaciares compuesto por los glaciares Frías, Cubo y Dickson, el cual es parte del CHPS. El objetivo del trabajo fue el desarrollo de Modelos Digitales de Elevación (DEMs) mediante la aplicación de técnicas de Interferometría de Radar de Apertura Sintética (InSAR) y su comparación con otros modelos existentes disponibles gratuitamente. En el monitoreo de glaciares, los DEMs pueden ser utilizados para determinar el balance de masas, mediante la comparación de alturas en distintos puntos de las zonas de ablación y acumulación del glaciar a través del tiempo. Esta metodología puede utilizarse complementariamente a otros métodos de balance de masas como el hidrológico o glaciológico, y es muy útil en zonas de difícil acceso como es el área de estudio. El monitoreo de glaciares es esencial para estimar cambios en su morfología, así como también comprender su comportamiento no solo en el presente sino a futuro.
Revista Cartográfica, 2021
El presente estudio contempla un análisis multitemporal con imágenes satelitales y datos meteorol... more El presente estudio contempla un análisis multitemporal con imágenes satelitales y datos meteorológicos de un grupo de glaciares denominados Glaciares Escondidos, ubicados al suroeste del Campo de Hielo Patagónico Sur. Compuesto por los glaciares Dickson, Cubo y Frías, este ha sufrido un marcado retroceso de sus frentes que se aceleró en los últimos 10 años. La alimentación de los glaciares Dickson y Frías se hacía originalmente por una sola corriente de hielo y solían actuar como diques naturales, evitando el flujo del agua entre el Lago Frías y el Lago Dickson. Debido a la pérdida de masa y el retroceso de sus frentes, las aguas que recorrían más de 250 km atravesando por completo la árida llanura de la Patagonia para desembocar en el Océano Atlántico, hoy lo hacen hacia el Océano Pacífico navegando las aguas de los fiordos chilenos que fluyen hacia el oeste. Se observan formaciones de lagos proglaciarios, un aumento en la velocidad de retroceso y una elevada velocidad de flujo d...
Este documento no es un paper, forma parte de un proyecto para cálculos de balance de masas sobre... more Este documento no es un paper, forma parte de un proyecto para cálculos de balance de masas sobre dos glaciares de la Patagonia, utilizando DEMs propios generados por técnicas de InSAR
Fil: Gari, Jorge Marcelo. Universidad Tecnologica Nacional. Facultad Regional Haedo; Argentina
Fil: Gari, Jorge Marcelo. Universidad Tecnologica Nacional. Facultad Regional Haedo; Argentina.
El presente estudio contempla un análisis multitemporal con imágenes satelitales y datos meteorol... more El presente estudio contempla un análisis multitemporal con imágenes satelitales y datos meteorológicos de un grupo de glaciares denominados Glaciares Escondidos, ubicados al suroeste del Campo de Hielo Patagónico Sur. Compuesto por los glaciares Dickson, Cubo o
Gorra y Frías, ha sufrido un marcado retroceso de sus frentes que se aceleró en los últimos 35 años. La alimentación de los glaciares Dickson y Frías se hacía originalmente por una sola corriente de hielo y solían actuar como diques naturales, evitando el flujo del agua entre el Lago
Frías y el Lago Dickson. Debido a la pérdida de masa y el retroceso de sus frentes, las aguas que recorrían más de 250 km atravesando por completo la árida llanura de la Patagonia para desembocar en el Océano Atlántico, hoy lo hacen hacia el Océano Pacífico navegando las aguas
de los fiordos chilenos que fluyen hacia el oeste. Se observan formaciones de lagos proglaciarios, un aumento en la velocidad de retroceso y una elevada velocidad de flujo del hielo, las cuales fueron estimadas con mediciones multitemporales y la técnica de offset tracking con imágenes radar. Asimismo, se presentan análisis de balances de masa sobre estos tres glaciares de los últimos 20 años, utilizando el método geodésico.
There has been a marked retreat of the glaciers located to the southwest of the Southern Patagoni... more There has been a marked retreat of the glaciers located to the southwest of the Southern Patagonian Ice Field, called Glaciares Escondidos (Hidden in english), especially in the last 35 years. The continental basin that divides Pacific and Atlantic oceans is currently located in these glaciers. Indeed, Dickson and Frías glaciers were originally fed by a single stream of ice. Starting at Cerro Cubo, the waters traveled the more than 250 km necessary to completely cross the arid plain of Patagonia,
and finally flow into the Atlantic Ocean. This paper presents a multitemporal study with remote sensing images from Landsat and Sentinel sensors, both medium spatial resolutions. Successively, we monitor their dynamics, observing formations of proglacial lakes, accumulation of sediments and movement of moraines, providing conclusions related to the water basin. Likewise, we estimated surface ice speeds on these glaciers using multitemporal measurements and offset tracking technique, based on satellite radar images. This area was selected because we observed great retreat in previous studies, which becomes more prominent since the 80s. It is worth mentioning that there has not been much research on this group of glaciers in the country.
The aim of this work consists in the delineation of the highest points of the Southern Patagonian... more The aim of this work consists in the delineation of the highest points of the Southern Patagonian Ice Field located between the parallels 48 ° 20 'of latitude S up to 51 ° 30' of latitude S, using satellite data from digital models of elevation and optical images and radar.
The Southern Patagonian Ice Field is the third largest continental ice supply in the world after Antarctica and Greenland, and is located in the southwest of the province of Santa Cruz, near the town of El Calafate. Los Glaciares National Park is one of the study areas found in this work, and cover part of this field. A digital elevation model or DEM according to its acronym in English, describes the topography of the terrain through bounded points defined as a triple composed of a value of altitude z defined at sea level, and their corresponding values of coordinates x and y, distributed in homogeneous shape on the earth's surface.
The DEMs were obtained from the data supplied by the SAR PALSAR sensor on the ALOS satellite (Advanced Earth Observation Satellite).
The structure of this height data is represented vectorially as well as raster, according to its source. They are extremely important to survey topographic and hydrographic networks, determine heights in
mountain areas and highlands as this case, as well as to perform slope calculations and contours that can be used in observations of landslides in the ice field and glaciers of hillside. Likewise, optical satellite were used to recognize the terrain and its representation in three-dimensional form, in order to achieve a better visualization of the topography and relief of the area. With this study we only intend to give an approximation for future cartographic representations carried out by official organisms.
This paper reviews a remote sensing method for estimating mass balance of Upsala Glacier. This gl... more This paper reviews a remote sensing method for estimating mass balance of Upsala Glacier. This glacier is located in Los Glaciares National Park, Santa Cruz, in Patagonia and it is the second largest glacier in Argentina, though it has exhibited dramatic retreats in the last years. A former methodology used in Viedma glacier was improved, determining characteristics of the glacier such as ice extent, terminus position, the Snow Line Altitude (SLA) in different dates, the relationship with the Equilibrium Line (ELA) and estimation of volume changes in a specific period of time. From this method, the change in local mass balance can be inferred according to ice and snow flow in a cycle. In absence of direct measurements, we apply remote sensing methods used in previous investigations. For this, we use optical Landsat 5-TM and Landsat 8-
OLI images, digital elevation models ASTER GDEM V2 and SRTM Mission (Shuttle Radar Topography Mission), both with a 30 m. pixel size, and topographic charts. Mass balance measurements were analyzed taking into account temperature and rainfall data from many sources, establishing a relationship among them and glacial retreat over a specified period of time. At the same time, public and free GIS database (provided by Instituto Geográfico Nacional in Argentina) was embedded in a geographic data system, consisting of vector layers with altitude information, dimensional points, contour lines and feature tables of the glaciers within the area of interest.
RESUMEN La utilización de imágenes satelitales permite recolectar información en sitios remotos, ... more RESUMEN La utilización de imágenes satelitales permite recolectar información en sitios remotos, abarcando una gran superficie de análisis y monitoreando visualmente áreas de difícil acceso, lo cual implicaría un gran costo tanto en tiempo como de recursos económicos. Esto es importante en una zona como la del Parque Nacional Los Glaciares en la provincia de Santa Cruz, donde se ubica el glaciar Viedma. A pesar de ser el mayor en tamaño del Parque Nacional, este glaciar ha sido muy poco estudiado, por lo que resulta esencial realizar algunas aproximaciones en materia de reconocimiento de su morfología y comportamiento, ya que ocupa una región de importancia natural, hídrica y paisajística. En el presente trabajo se buscó probar metodologías de estudio y clasificación de estructuras de hielo en el Glaciar Viedma combinando imágenes ópticas y de radar. Se estudió la capacidad de la imagen radar de la misión Sentinel 1A de la ESA (European Space Agency: Agencia Espacial Europea) en combinación con una imagen óptica del satélite SPOT 5 (Satellite Pour l'Observation de la Terre: Satélite Para la Observación de la Tierra), a partir de técnicas de procesamiento digitales que integran la información de ambas imágenes. Se destaca la importancia del uso de la tecnología radar como una ayuda invalorable para el estudio de zonas con características climáticas típicas de la Cordillera Patagónica, donde la mayor parte del tiempo se encuentra cubierto de nubes. Se evaluó de esta forma el aporte que ofrecen ambos sensores para definir y caracterizar los tipos de hielo y sus combinaciones con detritos rocosos, agua y nieve, que puede encontrarse en un glaciar de estas magnitudes, generando una cartografía temática de las unidades identificadas. ABSTRACT Remote sensing approaches allow for regular monitoring in remote areas, with large coverage. The increased availability of imagery from these platforms allows extending the measurements of hardly accessible terrains, with low financial costs and longer time spans. This is of main interest in Parque Nacional Los Glaciares in Santa Cruz, where Viedma glacier is placed. Despite it is the greatest glacier in the National Park, it has been slightly investigated, consequently it is of paramount importance to start some approaches regarding its morphology and behavior, since it is located in a natural and enchanting scenery and it is hydric resource. In the following, we present the methodology for classifying ice structures in Viedma glacier working with optical and radar imagery. The capability of the combination of ESA Sentinel 1A radar image and SPOT 5 (Satellite Pour l'Observation de la Terre) optical image was studied. For this, digital processing techniques where applied, incorporating information from both images. We emphasize the importance of radar technology as a valuable support for the monitoring of landscapes with unstable weather, as typical in the Patagonian Cordillera, where most of the time the meteorological condition is cloudy. The contribution of both sensors was evaluated in order to define and characterize different sorts of ice, also combined with soil debris, water and snow, found in such glacier. As a result, we obtained a thematic map with the identified classes.
Dinámica del movimiento en los Glaciares Escondidos del Campo de Hielo Patagónico Sur, 2020
There has been a marked retreat of the glaciers located to the southwest of the Southern Patagoni... more There has been a marked retreat of the glaciers located to the southwest of the Southern Patagonian Ice Field, called Glaciares Escondidos (Hidden in english), especially in the last 35 years. The continental basin that divides Pacific and Atlantic oceans is currently located in these glaciers. Indeed, Dickson and Frías glaciers were originally fed by a single stream of ice. Starting at Cerro Cubo, the waters traveled the more than 250 km necessary to completely cross the arid plain of Patagonia,
and finally flow into the Atlantic Ocean. This paper presents a multitemporal study with remote sensing images from Landsat and Sentinel sensors, both medium spatial resolutions. Successively, we monitor their dynamics, observing formations of proglacial lakes, accumulation of sediments and movement of moraines, providing conclusions related to the water basin. Likewise, we estimated surface ice speeds on these glaciers using multitemporal measurements and offset tracking technique, based on satellite radar images. This area was selected because we observed great retreat in previous studies, which becomes more prominent since the 80s. It is worth mentioning that there has not been much research on this group of glaciers in the country.
Representación topográfica mediante imágenes satelitales sobre el campo de hielo patagónico sur, 2019
The aim of this work consists in the delineation of the highest points of the Southern Patagonian... more The aim of this work consists in the delineation of the highest points of the Southern Patagonian Ice Field located between the parallels 48 ° 20 'of latitude S up to 51 ° 30' of latitude S, using satellite data from digital models of elevation and optical images and radar.
The Southern Patagonian Ice Field is the third largest continental ice supply in the world after Antarctica and Greenland, and is located in the southwest of the province of Santa Cruz, near the town of El Calafate. Los Glaciares National Park is one of the study areas found in this work, and cover part of this field.
A digital elevation model or DEM according to its acronym in English, describes the topography of the terrain through bounded points defined as a triple composed of a value of altitude z defined at sea level, and their corresponding values of coordinates x and y, distributed in homogeneous shape on the earth's surface.
The DEMs were obtained from the data supplied by the SAR PALSAR sensor on the ALOS satellite (Advanced Earth Observation Satellite).
The structure of this height data is represented vectorially as well as raster, according to its source. They are extremely important to survey topographic and hydrographic networks, determine heights in mountain areas and highlands as this case, as well as to perform slope calculations and contours that can be used in observations of landslides in the ice field and glaciers of hillside. Likewise, optical satellite were used to recognize the terrain and its representation in three-dimensional form, in order to achieve a better visualization of the topography and relief of the area.
With this study we only intend to give an approximation for future cartographic representations carried out by official organisms.
Estimación de la velocidad de desplazamiento del hielo en el Glaciar Upsala mediante imágenes SAR, 2018
The main objective of this work is the estimation of the speed ice flow on the Upsala Glacier usi... more The main objective of this work is the estimation of the speed ice flow on the Upsala Glacier using radar images. The Upsala Glacier is one of the temperate glaciers of high scientific interest in the Southern Patagonian Ice Field that presents a combination of processes and mechanisms such as rapid frontal recession, surface speed variations, changes in mass balance and ablation rates, as well as loss of thickness and high averages of calving, which make it a highly active glacier especially since 1970 onwards being for this reason chosen as a glacier model of the Southern Ice Field. The capacity of the module for radar processing of ESA's SNAP software was investigated in a similar way, particularly the technique of offset tracking in glaciers. Two radar images of the SAR Sentinel 1-A satellite were processed with a difference of 12 days of acquisition, obtaining ice speed maps during the study period. At the same time, the retreat data of the glacier investigated with optical images was updated since 1981.
El objetivo principal de este trabajo es la estimación de la velocidad del flujo de hielo sobre el glaciar Upsala utilizando imágenes radar. El glaciar Upsala es uno de los glaciares temperados de alto interés científico en el Campo de Hielo Patagónico Sur que presenta una combinación de procesos y mecanismos tales como retroceso frontal rápido, variaciones de la velocidad superficial, cambios en el balance de masa y tasas de ablación, así como pérdida de espesor y altos promedios de calving, lo que lo convierten en un glaciar altamente activo en especial desde 1970 en adelante siendo por esta razón elegido como modelo de glaciar del Campo de Hielo Sur. De igual manera, se investigó la capacidad del módulo para procesamiento radar del software SNAP de la ESA, particularmente la técnica de offset tracking en glaciares. Se procesaron dos imágenes radar del satélite SAR Sentinel 1-A con diferencia de 12 días de adquisición, obteniendo mapas de velocidad de hielo durante el período de estudio. Paralelamente, se actualizaron los datos de retroceso del glaciar investigado con imágenes ópticas desde el año 1981. Palabras clave: Glaciar Upsala-Offset tracking-Sentinel-Velocidad de hielo
Este documento no es un paper, forma parte de un proyecto para cálculos de balance de masas sobre... more Este documento no es un paper, forma parte de un proyecto para cálculos de balance de masas sobre dos glaciares de la Patagonia, utilizando DEMs propios generados por técnicas de InSAR