Search results for "observation [Cosmology]"
showing 10 items of 18 documents
Cloud detection on the Google Earth engine platform
2017
The vast amount of data acquired by current high resolution Earth observation satellites implies some technical challenges to be faced. Google Earth Engine (GEE) platform provides a framework for the development of algorithms and products built over this data in an easy and scalable manner. In this paper, we take advantage of the GEE platform capabilities to exploit the wealth of information in the temporal dimension by processing a long time series of satellite images. A cloud detection algorithm for Landsat-8, which uses previous images of the same location to detect clouds, is implemented and tested on the GEE platform.
Transferring deep learning models for cloud detection between Landsat-8 and Proba-V
2020
Abstract Accurate cloud detection algorithms are mandatory to analyze the large streams of data coming from the different optical Earth observation satellites. Deep learning (DL) based cloud detection schemes provide very accurate cloud detection models. However, training these models for a given sensor requires large datasets of manually labeled samples, which are very costly or even impossible to create when the satellite has not been launched yet. In this work, we present an approach that exploits manually labeled datasets from one satellite to train deep learning models for cloud detection that can be applied (or transferred) to other satellites. We take into account the physical proper…
Autism spectrum disorders in children affected by Duchenne muscular dystrophy
2018
Background Duchenne muscular dystrophy (DMD) is the most frequent and severe form of the dystrophinopathies. The literature shows that about 30-40% of DMD subjects have intellectual disability. In males with Duchenne muscular dystrophy, neuropsychiatric disorders have also been observed: attention deficit disorder and hyperactivity, autism spectrum disorders, and obsessive-compulsive disorder. Duchenne muscular dystrophy is not just a muscle disorder, but also a disease that affects the brain. The aim of the present study was to describe a case series of children with Duchenne muscular dystrophy that have also the presence of autism spectrum disorders (ASDs). They have been assessed by mean…
Role of sensorimotor areas in early detection of motor errors: An EEG and TMS study
2019
Abstract Action execution is prone to errors and, while engaged in interaction, our brain is tuned to detect deviations from what one expects from other’s action. Prior research has shown that Event-Related-Potentials (ERPs) are specifically modulated by the observation of action mistakes interfering with goal achievement. However, in complex and modular actions, embedded motor errors do not necessarily produce an immediate effect on the global goal. Here we dissociate embedded motor goals from global action goals by asking subjects to observe familiar but untrained knotting actions. During knotting an embedded motor error (i.e. the rope is inserted top-down instead of bottom-up during the …
Aviation Contrail Cirrus and Radiative Forcing Over Europe During 6 Months of COVID‐19
2021
Abstract The COVID‐19 pandemic led to a 72% reduction of air traffic over Europe in March–August 2020 compared to 2019. Modeled contrail cover declined similarly, and computed mean instantaneous radiative contrail forcing dropped regionally by up to 0.7 W m−2. Here, model predictions of cirrus optical thickness and the top‐of‐atmosphere outgoing longwave and reflected shortwave irradiances are tested by comparison to Meteosat‐SEVIRI‐derived data. The agreement between observations and modeled data is slightly better when modeled contrail cirrus contributions are included. The spatial distributions and diurnal cycles of the differences in these data between 2019 and 2020 are partially caused…
Permanent Stations for Calibration/Validation of Thermal Sensors over Spain
2016
The Global Change Unit (GCU) at the University of Valencia has been involved in several calibration/validation (cal/val) activities carried out in dedicated field campaigns organized by ESA and other organisms. However, permanent stations are required in order to ensure a long-term and continuous calibration of on-orbit sensors. In the framework of the CEOS-Spain project, the GCU has managed the set-up and launch of experimental sites in Spain for the calibration of thermal infrared sensors and the validation of Land Surface Temperature (LST) products derived from those data. Currently, three sites have been identified and equipped: the agricultural area of Barrax (39.05 N, 2.1 W), the mars…
ESA's sentinel missions in support of Earth system science
2012
Abstract The spatial and temporal characteristics of the new Sentinel missions, primarily designed to provide routine multidisciplinary observations for operational services, are also very suitable for addressing some of the challenges associated with advancing Earth System sciences. The Sentinels are ensuring long-term observational commitment and will operate a range of instruments with different spectral bands and spatial resolutions with global coverage and high revisit times. The complexity of Earth System models has been increasing gradually and most simulations of future climate and Earth system evolution are based on coupled models that include aspects of physics, bio/geo-chemistry,…
Estimating crop primary productivity with Sentinel-2 and Landsat 8 using machine learning methods trained with radiative transfer simulations
2019
Abstract Satellite remote sensing has been widely used in the last decades for agricultural applications, both for assessing vegetation condition and for subsequent yield prediction. Existing remote sensing-based methods to estimate gross primary productivity (GPP), which is an important variable to indicate crop photosynthetic function and stress, typically rely on empirical or semi-empirical approaches, which tend to over-simplify photosynthetic mechanisms. In this work, we take advantage of all parallel developments in mechanistic photosynthesis modeling and satellite data availability for an advanced monitoring of crop productivity. In particular, we combine process-based modeling with …
Brancati su Pirandello e il pirandellismo
2019
Nel romanzo breve "Sogno di un valzer" uscito a puntate su “Quadrivio”, dal 5 giugno al 14 agosto 1938, Vitaliano Brancati mette in scena, tra osservazione dei luoghi e rilevamento di costume, un’umanità fuori misura, continuamente in bilico tra realtà e sogno. A Caltanissetta (Nissa) la città nel cui Istituto magistrale lo scrittore, voltate le spalle alla Roma fascista, è venuto a insegnare, personaggi non appariscenti, insignificanti, che tuttavia covano desideri, si arrovellano in domande metafisiche. Prende così forma il leitmotiv delle critica al pirandellismo che più volte con ironia sottile affiora negli scritti brancatiani. Il saggio mostra come esso si intrecci con la comicità sul…
Multitemporal Cloud Masking in the Google Earth Engine
2018
The exploitation of Earth observation satellite images acquired by optical instruments requires an automatic and accurate cloud detection. Multitemporal approaches to cloud detection are usually more powerful than their single scene counterparts since the presence of clouds varies greatly from one acquisition to another whereas surface can be assumed stationary in a broad sense. However, two practical limitations usually hamper their operational use: the access to the complete satellite image archive and the required computational power. This work presents a cloud detection and removal methodology implemented in the Google Earth Engine (GEE) cloud computing platform in order to meet these r…