Search results for "Sentinel"

Turbidez y profundidad de disco de Secchi con Sentinel-2 en embalses con diferente estado trófico en la Comunidad Valenciana

2019

[ES] En los estudios de calidad de aguas por teledetección, uno de los principales indicadores es la transparencia o turbidez del agua. La transparencia puede ser medida in situ mediante la profundidad del disco de Secchi (SD), y la turbidez con un turbidímetro. En las últimas décadas se han utilizado diferentes relaciones entre bandas de diferentes sensores obtenidas por teledetección para la estimación de estos parámetros. En este trabajo, a partir de datos de campo obtenidos a lo largo de 2017 y 2018 en embalses de la cuenca del Júcar con gran variedad de estados tróficos, se han calibrado diferentes índices y bandas para poder estimar la transparencia a partir de imágenes Sentinel-2 (S2…

Multitemporal water quality study in Sitjar (Castelló, Spain) reservoir using Sentinel-2 images

2020

[EN] Water quality is a subject of intense scientific inquiry because of its repercussion in human’s life, agriculture or even energy generation. Remote sensing can be used to control water masses by analyzing biophysical variables. Chlorophyll-a (Chl-a) and Total Suspended Solids (SS) are a well-known feature of water quality. These variables have been measured in Sitjar reservoir (Castelló, Spain) as a part of the project Ecological Status of Aquatic Systems with Sentinel Satellites (ESAQS), in order to compare the results with satellite reflectance data. Two processes were compared to correct atmospherically the level 1C Sentinel 2 (S2) images. The results show that Case 2 Regional Coast…

Quantifying Fundamental Vegetation Traits over Europe Using the Sentinel-3 OLCI Catalogue in Google Earth Engine

2022

Thanks to the emergence of cloud-computing platforms and the ability of machine learning methods to solve prediction problems efficiently, this work presents a workflow to automate spatiotemporal mapping of essential vegetation traits from Sentinel-3 (S3) imagery. The traits included leaf chlorophyll content (LCC), leaf area index (LAI), fraction of absorbed photosynthetically active radiation (FAPAR), and fractional vegetation cover (FVC), being fundamental for assessing photosynthetic activity on Earth. The workflow involved Gaussian process regression (GPR) algorithms trained on top-of-atmosphere (TOA) radiance simulations generated by the coupled canopy radiative transfer model (RTM) SC…

Disentangling local agronomic practices from agricultural landscape effects on pest biological control

2019

International audience; The biological control of crop pests is a valuable service provided by various beneficial organisms that are naturally present in agricultural landscapes. Semi-natural habitats has long been recognized as essential to preserve beneficial insects, but proof of their efficiency to enhance biological control of pests remains non conclusive. Here, we examined the variability of landscape effect on biological pest control and the way local agronomic practices may modulate it. Biological pest control was monitored in 80 commercial fields (arable crops and orchards) during three consecutive years in four contrasting French agricultural landscapes distributed along a double …

Sentinel Lymph Node in Aged Endometrial Cancer Patients “The SAGE Study”: A Multicenter Experience

2021

ObjectiveThe incidence of endometrial cancer is increasing in elderly people. Considering that aging progressively affects lymphatic draining function, we aimed to define its impact on IGC uptake during SLN mapping.MethodsA multicenter retrospective cohort of endometrial cancer patients with apparently early-stage endometrial cancer undergoing complete surgical staging with SLN dissection was identified in four referral cancer centers from May 2015 to March 2021. Patients were classified in Group 1 (<65 years old) and Group 2 (≥65 years old). The primary endpoint was the assessment of the overall, bilateral, and unsuccessful SLN mapping in the two groups. Secondary outcomes were the …

Usutu virus activity in Austria, 2001–2002

2003

Usutu virus (USUV), a member of the mosquito-borne clade within the Flaviviridae family, was responsible for avian mortality in Austria in 2001. In 2002, the virus continued to kill birds, predominantly blackbirds. High numbers of avian deaths were recorded within the city of Vienna and in surrounding districts of the federal state of Lower Austria, while single die-offs were noticed in the federal states of Styria and Burgenland. A total of 72 birds were submitted for laboratory examination, 30 of which tested positive for USUV by immunohistochemistry and/or polymerase chain reaction. Laboratory-confirmed cases of USUV infection originated from the federal states of Vienna and Lower Austri…

VALUTAZIONE DELL’INCIDENZA DEL LINFEDEMA SECONDARIO ALLA PROCEDURA DELLA BIOPSIA DEL LINFONODO SENTINELLA NEL TRATTAMENTO DEL MELANOMA DEL TRONCO E D…

A sun-induced vegetation fluorescence retrieval method from top of atmosphere radiance for the FLEX/Sentinel-3 TanDEM mission

2015

A new fluorescence retrieval method is proposed to support ESA's 8th Earth Explorer FLuorescence EXplorer/Sentinel-3 (FLEX-S3) candidate tandem mission. FLEX is the first mission specially dedicated to measure the Sun-Induced vegetation chlorophyll fluorescence (SIF) strongly related with the vegetation photosynthetic activity. Most hyperspectral fluorescence retrieval algorithms available in the literature are very sensitive to true reflectance modelization and/or they assume the atmospheric status as known. The proposed algorithm delivers the retrieval of full fluorescence spectrum at canopy level by using only Top Of Atmosphere (TOA) radiances from S3 and FLEX as input. Once the spatial …

Estudio integral de humedales altoandinos (andean peatlands) con Teledetección y SIG

2022

La Reserva de Producción de Fauna Chimborazo (RPFCH) es un ecosistema de alto valor situado en los andes ecuatorianos, ocupado en su mayor parte por turberas, también llamados bofedales o peatlands. El objetivo de esta tesis es el estudio de dichos ecosistemas a partir de una extensa base de datos de campo obtenida en 2016 y usando datos de teledetección óptica y radar y variables topográficas, ambientales y climáticas con SIG. Para ello se analizaron los mejores métodos para el cartografiado de los peatlands en la RPFCH, la estimación del carbono bajo el suelo (COS) en la capa 0-30 cm y la estimación del carbono almacenado en la vegetación calculado a partir de la biomasa. Como resultado s…

Surgical treatment of early breast cancer in day surgery.

2007

Quadrantectomy and associated sentinel lymph node biopsy (SLNB) is currently employed in most breast surgery centres as the gold standard in the treatment of early breast cancer. This approach has a modest morbidity and can usually be performed in a day-surgery regimen, leading to best acceptance by the patients. This reports outlines the experience of our Breast Unit with quadrantectomy and SLNB in day surgery for early breast cancer. One hundred patients presenting to our institution with primary invasive breast cancer measuring less than 3 cm and clinically negative axillary nodes underwent quadrantectomy and SLNB in day surgery. For 60 women with breast cancer the sentinel node was nega…