Search results for "satellite"

showing 10 items of 1031 documents

Monitoring tropical forests under a functional perspective with satellite-based vegetation optical depth.

2020

Monitoring ecosystem functions in forests is a priority in a climate change scenario, as climate-induced events may initially alter the functions more than slow-changing attributes, such as biomass. The ecosystem functional properties (EFPs) are quantities that characterize key ecosystem processes. They can be derived by point observations of gas and energy exchanges between the ecosystems and the atmosphere that are collected globally at FLUXNET flux tower sites and upscaled at ecosystem level. The properties here considered describe the ability of ecosystems to optimize the use of resources for carbon uptake. They represent functional forest information, are dependent on environmental dri…

Settore ING-INF/02010504 meteorology & atmospheric sciencesClimate Changeecosystem functional properties0211 other engineering and technologiesFluxClimate changeGPPmax02 engineering and technologyForestsAtmospheric sciences01 natural sciencesvegetation optical depthTreesFluxNetClimate change scenarioLUEEnvironmental ChemistryEcosystemWater contentEcosystem021101 geological & geomatics engineering0105 earth and related environmental sciencesGeneral Environmental ScienceGlobal and Planetary ChangeBiomass (ecology)Ecology15. Life on landSouth America13. Climate actionAfricaEnvironmental scienceSatelliteGlobal change biologyREFERENCES
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Rateless Codes Performance Analysis in Correlated Channel Model for GEO Free Space Optics Downlinks

2012

Settore ING-INF/03 - TelecomunicazioniFree Space Optics (FSO) technologies for satellite communications offer several advantages: wide bandwidth high rate capability immunity to electromagnetic interference and small equipment size. Thus they are suitable for inter-satellite links deep space communications and also for high data rate ground-to-satellite/satellite-to-ground communications. Nevertheless FSO links suffer impairments that cause power signal degradation at the receiver. Scattering and absorption cause power signal attenuations predictable by suitable deterministic models. Optical turbulence causes random irradiance fluctuations which can generate signal fading events and can thereby only be predicted by statistical models. Attenuation and fading events can corrupt FSO links and so it would be recommended to add mitigation error codes on the communication link. FSO channel can be described as an erasure channel: fading events can cause erasure errors. We have identified in rateless codes (RCs) a suitable solution to be employed in FSO links. RCs do not need feedback and they add a redundant coding on the source data that allows the receiver to recover the whole payload despite erasure errors. We implemented two different of rateless codes: Luby Transform (LT) and Raptor. We analyzed their performances on a simulated turbulent GEO FSO downlink (1 Gbps - OOK modulation) at a 106 μm wavelength and for different values of zenith angles. Assuming a plane-wave propagation and employing Hufnagel-Valley we modeled the downlink using: 1) a temporal correlated channel model based on Gamma-Gamma probability distribution and 2) an irradiance covariance function that we converted on a time function using Taylor frozen eddies hypothesis. Our new channel model is able to simulate irradiance fluctuations at different turbulence conditions as it will be shown in the full paper. We will also report performance results of LT and Raptor codes at overhead range varying between 0 and 50% and for different values of source packets.Settore ING-INF/01 - Elettronica
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A Multichannel Information System to Build and Deliver Rich User-Experiences in Exhibits and Museums

2011

In this article a multichannel information system to build and deliver rich user experiences in exhibits and museums is presented. The system was designed to use information about a particular exhibit or museum while delivering a wide user experience based on different distribution channels. The overall information is used to build different solutions that can be delivered simultaneously on different media from touch-screen installations to portable devices like smart phones. Moreover, all the devices signed in the environment are able to communicate to each others to increase the level of the usability of the system. A case study and analysis of experimental results are also provided.

Settore ING-INF/05 - Sistemi Di Elaborazione Delle InformazioniMultimediaComputer sciencebusiness.industrySatellite broadcastingUsabilitycomputer.software_genrePersonalizationExhibitionUser experience designServerGlobal Positioning SystemInformation systemMultichannel Information System User-experience exhibition integration musuems personalizationbusinesscomputer
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Methods and Techniques for Multi-source Data Analysis and Fusion

This work has been inspired by the recent trend in remote sensing and environmental data acquisition. Remote sensing techniques allow us to measure information about an object without touching it. In the last decades remote sensing via satellites has been used in various applications such as Earth observation, weather and storm predictive analysis, atmospheric monitoring, climate change, human-environment interactions. Sensors on airborne and satellite platforms have been recording signals from space for many years, giving rise to a huge amount of data. Some data are processed on-board but others are treated and post-processed in ground stations. Signal and image processing are widely appli…

Settore ING-INF/05 - Sistemi Di Elaborazione Delle InformazioniRemote sensing satellite images signal processing software radio visual saliency dataset eye-tracking color vision deficiency
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A Low Cost Solution for NOAA Remote Sensing

2018

United States National Oceanic and Atmospheric Administration (NOAA) weather satellites adopt Advanced Very High Resolution Radiometer (AVHRR) sensors to acquire remote sensing data and broadcast Automatic Picture Transmission (APT) images. The orientation of the scan lines is perpendicular to the orbit of the satellite. In this paper we propose a new low cost solution for NOAA remote sensing. More in detail, our method focuses on the possibility of directly sampling the modulated signal and processing it entirely in software enabled by recent breakthroughs on Software Defined Radios (SDR) and CPU computational speed, while keeping the costs extremely low. We aim to achieve good results wit…

Settore ING-INF/05 - Sistemi Di Elaborazione Delle InformazioniSignal processingComputer Networks and CommunicationsComputer science0211 other engineering and technologiesComputer Science Applications1707 Computer Vision and Pattern RecognitionInformation System02 engineering and technologyRemote SensingRemote sensing (archaeology)Signal ProcessingInformation systemCommunications satelliteSatellite CommunicationElectrical and Electronic Engineering021101 geological & geomatics engineeringRemote sensingProceedings of the 7th International Conference on Sensor Networks
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Can the tumor-agnostic evaluation of MSI/MMR status be the common denominator for the immunotherapy treatment of patients with several solid tumors?

2022

Alterations in short-repetitive DNA sequences, known as microsatellite instability (MSI), can reflect deficiencies in Mismatch Repair (MMR) system which represents a major player in DNA integrity maintenance. The incidence of MSI-H/dMMR has been shown to be variable depending on the tumor type. Several studies confirmed that dMMR/MSI status, although less frequent than PD-L1 expression, may better predict response to immune-checkpoint inhibitors (ICIs) in patients with solid tumors. In October 2016, the FDA granted pembrolizumab as breakthrough therapy for the treatment of non-CRC, MSI-H/dMMR tumors, providing, for the first time, a tumor-agnostic indication. In the next future, the tissue-…

Settore MED/06 - Oncologia MedicaHematologyMMR deficiencyColorectal cancerMMRPD-1/PD-L1DNA Mismatch RepairTumor-agnostic therapyOncologyNeoplasmsSolid tumorsHumansMicrosatellite InstabilityImmunotherapyColorectal NeoplasmsMSI
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Adapting to Dynamic LEO-B5G Systems : Meta-Critic Learning Based Efficient Resource Scheduling

2022

Low earth orbit (LEO) satellite-assisted communications have been considered as one of key elements in beyond 5G systems to provide wide coverage and cost-efficient data services. Such dynamic space-terrestrial topologies impose exponential increase in the degrees of freedom in network management. In this paper, we address two practical issues for an over-loaded LEO-terrestrial system. The first challenge is how to efficiently schedule resources to serve the massive number of connected users, such that more data and users can be delivered/served. The second challenge is how to make the algorithmic solution more resilient in adapting to dynamic wireless environments.To address them, we first…

Signal Processing (eess.SP)FOS: Computer and information sciencesdynamic environmentComputer Science - Machine Learningreinforcement learningmeta-critic learningComputer Science - Artificial Intelligence5G-tekniikkaresursointiMachine Learning (cs.LG): Electrical & electronics engineering [C06] [Engineering computing & technology]LEO satelliteslangaton tiedonsiirtoresources allocationalgoritmitFOS: Electrical engineering electronic engineering information engineeringElectrical and Electronic EngineeringElectrical Engineering and Systems Science - Signal Processing: Ingénierie électrique & électronique [C06] [Ingénierie informatique & technologie]Applied MathematicstietoliikennesatelliititComputer Science ApplicationsArtificial Intelligence (cs.AI)koneoppiminenresource schedulinglangattomat verkot
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Proba-V cloud detection Round Robin: Validation results and recommendations

2017

This paper discusses results from 12 months of a Round Robin exercise aimed at the inter-comparison of different cloud detection algorithms for Proba-V. Clouds detection is a critical issue for satellite optical remote sensing, since potential errors in cloud masking directly translates into significant uncertainty in the retrieved downstream geophysical products. Cloud detection is particularly challenging for Proba-V due to the presence of a limited number of spectral bands and the lack of thermal infrared bands. The main objective of the project was the inter-comparison of several cloud detection algorithms for Proba-V over a wide range of surface types and environmental conditions. Prob…

Signal processingPixelArtificial neural networkbusiness.industryCloud computingSpectral bandsLinear discriminant analysiscomputer.software_genreThresholdingGeographySatelliteData miningbusinesscomputerRemote sensing2017 9th International Workshop on the Analysis of Multitemporal Remote Sensing Images (MultiTemp)
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An Effective Satellite Remote Sensing Tool Combining Hardware and Software Solutions

2019

In this paper we propose a new effective remote sensing tool combining hardware and software solutions as an extension of our previous work. In greater detail the tool consists of a low cost receiver subsystem for public weather satellites and a signal and image processing module for several tasks such as signal and image enhancement, image reconstruction and cloud detection. Our solution allows to manage data from satellites effectively with low cost components and portable software solutions. We aim at sampling and processing of the modulated signal entirely in software enabled by Software Defined Radios (SDR) and CPU computational speed overcoming hardware limitation such as high receive…

Signal processingSettore ING-INF/05 - Sistemi Di Elaborazione Delle Informazioni010504 meteorology & atmospheric sciencesComputer scienceNoise (signal processing)business.industryBandwidth (signal processing)0211 other engineering and technologiesImage processing02 engineering and technologySoftware-defined radioCloud detectionRemote sensing01 natural sciencesSoftwareDemodulationWeather satelliteSatellite communicationSoftware architecturebusinessComputer hardware021101 geological & geomatics engineering0105 earth and related environmental sciences
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Detection of a reservoir water level using shape similarity metrics

2017

The matching between reservoirs’ water edge and digital elevation model’s (DEM) contour lines allowed determining the water level at the acquisition date of satellite images. A preliminary study was conducted on the Castello dam (Magazzolo Lake), between Alessandria della Rocca and Bivona (Agrigento, south-Italy). The accuracy assessment of the technique was than evaluated from the comparison between classified and reference objects using similarity metrics about the shape, theme, edge and position, through the plugin STEP of open source software GIS. Moreover, an independent GIS technique was implemented to evaluate the water level, based on a distances’ array between existing contour line…

Similarity (geometry)water surfaceMatching (graph theory)Computer science0211 other engineering and technologies0507 social and economic geography02 engineering and technologyPosition (vector)Digital elevation model021101 geological & geomatics engineeringbusiness.industry05 social sciencesSettore ICAR/02 - Costruzioni Idrauliche E Marittime E IdrologiaDEMPattern recognitionWater levelWater levelContour lineSatelliteEnhanced Data Rates for GSM EvolutionArtificial intelligencebusiness050703 geographyLandsatSettore ICAR/06 - Topografia E CartografiaSAR
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