Search results for "Payload"

showing 10 items of 37 documents

Mass Estimation of Self-Contained Linear Electro-Hydraulic Actuators and Evaluation of the Influence on Payload Capacity of a Knuckle Boom Crane

2019

Abstract Self-contained linear hydraulic drives are characterized by having integrated the hydraulic power unit e.g. electrical prime mover, hydraulic pumps etc. and the hydraulic cylinder in a single compact unit. Compared to the hydraulic cylinder itself, the mass of the self-contained linear actuator is significantly larger. For some applications, e.g. crane manipulators the additional mass of the actuators compared to conventional valve-controlled hydraulics, may reduce the payload capacity, which is a central performance parameter. As a case study, a medium sized two link knuckle boom crane is modelled and by assuming the force capability of the hydraulic cylinders to be the limiting f…

PayloadHydraulicsComputer scienceElectro hydraulicBoomlaw.inventionHydraulic cylinderKnucklemedicine.anatomical_structurelawmedicineActuatorHydraulic pumpMarine engineering
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OMC: An Optical Monitoring Camera for INTEGRAL

1998

The INTEGRAL payload has been designed to study simultaneously gamma-ray sources in a wide field of view over many decades in energy (around 2 eV + 4 keV − 20 MeV) and thus make a major contribution to short time-scale high-energy astrophysics. The OMC will observe the optical emission from the prime targets of the gamma-ray instruments with the support of the x-ray monitor. This capability will provide invaluable diagnostic information on the nature and the physics of the sources over a broad wavelength range. The main scientific objectives will be: (1) to monitor the optical emission from the sources observed by the gamma- and x-ray instruments, measuring the time and intensity structure …

PhysicsBrightnessPixelbusiness.industryPayloadApertureAstrophysics::High Energy Astrophysical PhenomenaField of viewLarge formatCondensed Matter PhysicsAtomic and Molecular Physics and OpticsOpticsTransient (oscillation)businessMathematical PhysicsEnergy (signal processing)Physica Scripta
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THE UFFO SLEWING MIRROR TELESCOPE FOR EARLY OPTICAL OBSERVATION FROM GAMMA RAY BURSTS

2013

While some space born observatories, such as SWIFT and FERMI, have been operating, early observation of optical after grow of GRBs is still remained as an unexplored region. The Ultra-Fast Flash Observatory (UFFO) project is a space observatory for optical follow-ups of GRBs, aiming to explore the first 60 seconds of GRBs optical emission. Using fast moving mirrors to redirect our optical path rather than slewing the entire spacecraft, UFFO is utilized to catch early optical emissions from GRB within 1 sec. We have developed the UFFO Pathfinder Telescope which is going to be on board of the Lomonosov satellite and launched in middle of 2012. We will discuss about scientific potentials of t…

PhysicsNuclear and High Energy PhysicsSpacecraftbusiness.industryPayloadAstrophysics::High Energy Astrophysical PhenomenaAstrophysics::Instrumentation and Methods for AstrophysicsGeneral Physics and AstronomyAstronomyAstronomy and AstrophysicsAstrophysicslaw.inventionTelescopeOptical pathlawObservatorySatelliteGamma-ray burstbusinessFermi Gamma-ray Space TelescopeModern Physics Letters A
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The INTEGRAL experiment

1998

The International Gamma-ray Astrophysics Laboratory (INTEGRAL) is conceived as the next logical step in gamma-ray astronomy after the US Compton Gamma-Ray Observatory (CGRO) and the French/Russian SIGMA mission. The INTEGRAL scientific payload consists of two main instruments (Imager and Spectrometer) and two monitor instruments (X-Ray Monitor and Optical Transient Camera). The INTEGRAL spectrometer "SPI" is optimized for detailed measurements of gamma-ray lines and mapping of diffuse sources. It combines a coded aperture mask with an array of large volume, high-purity germanium detectors. The detectors make precise measurements of the gamma-ray energies over the 20 keV-8 MeV energy range. …

PhysicsNuclear and High Energy PhysicsSpectrometerPayloadbusiness.industryAstrophysics::High Energy Astrophysical PhenomenaMonte Carlo methodDetectorAstrophysics::Instrumentation and Methods for AstrophysicsAtomic and Molecular Physics and OpticsOpticsObservatoryAngular resolutionCoded apertureTransient (oscillation)business
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The EUSO Data Simulation and Analysis Tree

2004

The "Extreme Universe Space Observatory - EUSO" is the first Space mission devoted to the exploration of the outermost bounds of the Universe through the investigation of the Extremely-High Energy Cosmic Rays, EECR, using the Earth atmosphere as a giant detector. The objective is to obtain a detailed description of the Cosmic Ray spectrum beyond 5×1019 eV together with a map of the arrival directions. EUSO will detect EECR looking at the streak of fluorescence light produced when such a particle interacts with the atmosphere. The signal will be detected after its propagation upward from the dark Earth atmosphere to the EUSO telescope accommodated, as external payload, on the International S…

PhysicsPayloadAstrophysics::High Energy Astrophysical Phenomenamedia_common.quotation_subjectAstrophysics::Instrumentation and Methods for AstrophysicsAstronomyCosmic rayUniverselaw.inventionTelescopeAtmosphere of EarthlawPhysics::Space PhysicsInternational Space StationAstrophysics::Earth and Planetary AstrophysicsEvent (particle physics)Event reconstructionmedia_common
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The X-ray gas scintillation spectrometer experiment on the first spacelab flight

1985

The First Spacelab mission, launched on Space ShuttleFlight STS-9 in November 1983 carried a multidisciplinary payload which was intended to demonstrate that valuable scientific results can be achieved from such short duration missions. The payload complement included a spectrometer to undertake observations of the brighter cosmic X-ray sources. The primary scientific objectives of this experiment were the study of detailed spectral features in cosmic X-ray sources and their associated temporal variations over a wide energy range from about 2 up to 30 keV. The instrument based on the gas scintillation proportional counter had an effective area of some 180 cm2 with an energy resolution of ∼9…

PhysicsScintillationCOSMIC cancer databaseSpectrometerPayloadbusiness.industryAstrophysics::High Energy Astrophysical PhenomenaAstrophysics::Instrumentation and Methods for AstrophysicsAstronomyProportional counterAstronomy and AstrophysicsCosmologyAstronomical spectroscopyOpticsSpace and Planetary ScienceScintillation counterbusinessAstrophysics and Space Science
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E-sail test payload of the ESTCube-1 nanosatellite

2014

The scientific mission of ESTCube-1, launched in May 2013, is to measure the electric solar wind sail (E-sail) force in orbit. The experiment is planned to push forward the development of the E-sail, a propulsion method recently invented at the Finnish Meteorological Institute. The E-sail is based on extracting momentum from the solar wind plasma flow by using long thin electrically charged tethers. ESTCube-1 is equipped with one such tether, together with hardware capable of deploying and charging it. At the orbital altitude of ESTCube-1 (660–680 km) there is no solar wind present. Instead, ESTCube-1 shall observe the interaction between the charged tether and the ionospheric plasma. The E…

Physicsta114Payloadbusiness.industryGeneral EngineeringPropulsionlaw.inventionSlip ringSolar windlawElectric sailAerospace engineeringIonosphereSpace researchbusinessVoltageProceedings of the Estonian Academy of Sciences
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Slewing mirror telescope of the UFFO-pathfinder: first report on performance in space

2017

To observe the early optical emissions from gamma ray bursts (GRBs), we built the Slew Mirror Telescope. It utilizes a 150 mm motorized mirror to redirect incoming photons from astrophysical objects within seconds and to track them as compensating satellite movements. The SMT is a major component of the UFFO-pathfinder payload, which was launched on April 28, 2016, onboard the Lomonosov satellite. For the first time, the slewing mirror system has been proven for the precision tracking of astrophysical objects during space operation. We confirmed that the SMT has 1.4 seconds of response time to the X-gamma-ray trigger, and is able to compensate for satellite drift and to track astrophysical …

Point spread functionPhysicsbusiness.industryPayloadAstrophysics::High Energy Astrophysical PhenomenaTrack (disk drive)Astrophysics::Instrumentation and Methods for AstrophysicsAstronomyTracking (particle physics)01 natural sciencesAtomic and Molecular Physics and OpticsOptical telescopelaw.inventionTelescopeOpticslaw0103 physical sciencesSatellite010306 general physicsbusinessGamma-ray burst010303 astronomy & astrophysicsOptics Express
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Minimal learning machine in hyperspectral imaging classification

2020

A hyperspectral (HS) image is typically a stack of frames, where each frame represents the intensity of a different wavelength of light. Each spatial pixel has a spectrum. In the classification of the HS image, each spectrum is classified pixel-by-pixel. In some of the real-time applications, the amount of the HS image data causes performance challenges. Those issues relate to the platforms (e.g. drones) payload restrictions, the issues of the available energy and to the complexity of the machine learning models. In this study, we introduce the minimal learning machine (MLM) as a computationally cheap training and classification machine learning method for the hyperspectral imaging classificatio…

Principal Component AnalysisMinimal Learning MachineArtificial neural networkPixelComputer sciencebusiness.industryFrame (networking)Payload (computing)spektrikuvausHyperspectral imagingPattern recognitionHyperspectral ImagingClassificationRandom forestSupport vector machineData pointkoneoppiminenkuvantaminenDistance LearningArtificial intelligencebusiness
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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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