Search results for "Satellite communication"

showing 8 items of 8 documents

Validation of a mapping and prediction model for human fasciolosis transmission in Andean very high altitude endemic areas using remote sensing data.

2001

The present paper aims to validate the usefulness of the Normalized Difference Vegetation Index (NDVI) obtained by satellite remote sensing for the development of local maps of risk and for prediction of human fasciolosis in the Northern Bolivian Altiplano. The endemic area, which is located at very high altitudes (3800-4100 m) between Lake Titicaca and the valley of the city of La Paz, presents the highest prevalences and intensities of fasciolosis known in humans. NDVI images of 1.1 km resolution from the Advanced Very High Resolution Radiometer (AVHRR) sensor on board the National Oceanic and Atmospheric Administration (NOAA) series of environmental satellites appear to provide adequate …

BoliviaFascioliasisGeographic information systemAdvanced very-high-resolution radiometerVeterinary (miscellaneous)Normalized Difference Vegetation IndexRisk FactorsmedicinePrevalenceHumansFasciolosisbusiness.industryAltitudeEffects of high altitude on humansmedicine.diseaseSatellite CommunicationsField (geography)Infectious DiseasesGeographyRemote sensing (archaeology)Insect ScienceLinear ModelsParasitologySatellitebusinessCartographyActa tropica
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Streaming for vehicular users via elastic proxy buffer management

2004

In this article we refer to the market of vehicular networks, where groups of customers located in the same public vehicle (e.g., a train or bus) connect to a terrestrial network through a wireless/satellite backbone link. Elastic buffering is a proxy management technique devised to decouple the multimedia information retrieval rate on the network backbone from the playout streaming rate at the user terminal. It has been shown in the past that the application of elastic buffering mechanisms in terrestrial networks brings significant advantages in terms of network effectiveness. We show that elastic buffering is an extremely effective means to reduce, or even eliminate, streaming service out…

Mobile radioService (systems architecture)Computer Networks and CommunicationsComputer scienceDelayed real time servicesMultimedia information retrievalCommunication channels (information theory)Resource sharing algorithmBuffer storageWirelessInformation retrievalWireless telecommunication systemsElectrical and Electronic EngineeringReal time streaming servicesProxy (statistics)Railroad car equipmentVehicular area networksBackbone networkInternetMobile computingVehicular ad hoc networkbusiness.industrySettore ING-INF/03 - TelecomunicazioniComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKSSatellite communication systemsElastic proxy buffer managementLocal area networksReal time systemsAlgorithms; Buffer storage; Communication channels (information theory); Information retrieval; Internet; Local area networks; Multimedia systems; Railroad car equipment; Real time systems; Satellite communication systems; Satellite links; Wireless telecommunication systems; Delayed real time services; Elastic proxy buffer management; Fast internet for fast train hosts (FIFTH); Real time streaming services; Resource sharing algorithm; Vehicular area networks; Mobile computingComputer Science ApplicationsTerminal (electronics)Fast internet for fast train hosts (FIFTH)businessSatellite linksAlgorithmsMultimedia systemsComputer network
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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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Satelliittijärjestelmän linkkibudjettianalyysi

2013

Tutkielmassa selvitetään kirjallisuuskatsauksen avulla DVB-S ja DVB-RCS standardien mukaisten interaktiivisten satelliittijärjestelmien linkkibudjettia. Toisen sukupolven standardien eli DVB-S2 ja DVB-RCS2 mukaisten järjestelmien erityispiirteiden huomioiminen linkkibudjetin kannalta on tutkielman keskeinen teema. Tutkielma pyrkii antamaan selkeän kuvan satelliittijärjestelmän linkkibudjetista sekä tuomaan näkökulmia satelliittijärjestelmien jatkotutkimukseen ja suunnittelutyöhön. The link budget analysis of the satellite system. This paper discusses the link budget of the satellite systems based on DVB-S and DVB-RCS standards. Used method is literature review. The key theme is to study spe…

suorituskykyDVBsatelliittijärjestelmätlinkkibudjettiDVB-Sstandarditlink budgettiedonsiirtoDVB-RCSDVB-S2satelliittiviestintäDVB-RCS2satellite communication
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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 global network for the control of snail-borne disease using satellite surveillance and geographic information systems

2001

Abstract At a team residency sponsored by the Rockefeller Foundation in Bellagio, Italy, 10-14 April 2000 an organizational plan was conceived to create a global network of collaborating health workers and earth scientists dedicated to the development of computer-based models that can be used for improved control programs for schistosomiasis and other snail-borne diseases of medical and veterinary importance. The models will be assembled using GIS methods, global climate model data, sensor data from earth observing satellites, disease prevalence data, the distribution and abundance of snail hosts, and digital maps of key environmental factors that affect development and propagation of snail…

Resource (biology)GIS DayGeographic information systemDatabases FactualInternational CooperationVeterinary (miscellaneous)SnailsGlobal HealthEnvironmental protectionGlobal networkAnimalsHumansSchistosomiasisMedicineGeographyDigital mappingbusiness.industryEnvironmental resource managementSatellite CommunicationsData sharingInfectious DiseasesInsect ScienceParasitologyThe InternetEnterprise GISbusinessActa Tropica
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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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Sensors / Cross-country skiing analysis and ski technique detection by high-precision kinematic global navigation satellite system

2019

Cross-country skiing (XCS) embraces a broad variety of techniques applied like a gear system according to external conditions, slope topography, and skier-related factors. The continuous detection of applied skiing techniques and cycle characteristics by application of unobtrusive sensor technology can provide useful information to enhance the quality of training and competition. (1) Background: We evaluated the possibility of using a high-precision kinematic global navigation satellite system (GNSS) to detect cross-country skiing classical style technique. (2) Methods: A world-class male XC skier was analyzed during a classical style 5.3-km time trial recorded with a high-precision kinemat…

MaleTime FactorsGPSVideo RecordingSTRIDEVideo cameraKinematics01 natural sciencesBiochemistryDisplacement (vector)ArticleAnalytical Chemistrylaw.invention03 medical and health sciences0302 clinical medicineTime trialImaging Three-DimensionallawSkiingHumansElectrical and Electronic Engineeringkinematic GNSSInstrumentationMathematicsbusiness.industryAltitude010401 analytical chemistry030229 sport sciencesGeodesySatellite CommunicationshiihtoAtomic and Molecular Physics and Optics0104 chemical sciencesBiomechanical PhenomenaGNSS applicationssatelliittipaikannusTrajectoryGlobal Positioning Systembusinessclassical techniquecross-country skiing
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