Search results for "Payload"
showing 10 items of 37 documents
First results from the PROBA/CHRIS hyperspectral/multiangular satellite system over land and water targets
2005
The Project for On-Board Autonomy (PROBA) platform developed by the European Space Agency was launched on October 22, 2001. The instrument payload includes the Compact High Resolution Imaging Spectrometer (CHRIS). The coupled system provides high spatial resolution hyperspectral/multi-angular data, which represents a new-generation source of information for Earth observation purposes. The first results obtained from the preprocessing (noise removal and geometric/atmospheric correction) of two different datasets, collected over agricultural crops and inland waters, are presented in this letter. In situ measurements are used to assess the quality of the data and to validate the processing alg…
Offshore Wind Payload Transfer Using Flexible Mobile Crane
2015
This article presents an offshore-simulated loading and unloading of a payload from a floating platform to a fixed structure. The experiments are performed in a dry-lab, where a Stewart platform is used to simulate the motion of the vessel. A hydraulically actuated vehicle loader crane is used to perform the tasks of payload transfer. The crane includes a hydraulic winch where the wire force is measured by a load cell. A mathematical model of the winch is derived and is experimentally verified. The control strategies include a heave compensation and a constant tension mode. A motion reference unit is used to generate the reference motion of the moving platform. Experimental results show the…
Modeling, simulation and design optimization of a hoisting rig active heave compensation system
2012
Published version of an article in the journal: International Journal of Machine Learning and Cybernetics. Also available from the publisher at: http://dx.doi.org/10.1007/s13042-012-0076-x The objective of this paper is to present an approach in developing a virtual active heave compensation system for a draw-works on a hoisting rig. A virtual system enables quicker overall product development time of a physical system as well as flexibility in optimizing the design parameters. Development of the virtual system started with the modelling of the draw-works and hoisting rig dynamics. Simulations of this model were run in two operational modes while subject to a sinusoidal wave: heave compensa…
Survey: Intrusion Detection Systems in Encrypted Traffic
2016
Intrusion detection system, IDS, traditionally inspects the payload information of packets. This approach is not valid in encrypted traffic as the payload information is not available. There are two approaches, with different detection capabilities, to overcome the challenges of encryption: traffic decryption or traffic analysis. This paper presents a comprehensive survey of the research related to the IDSs in encrypted traffic. The focus is on traffic analysis, which does not need traffic decryption. One of the major limitations of the surveyed researches is that most of them are concentrating in detecting the same limited type of attacks, such as brute force or scanning attacks. Both the …
The enhanced X-ray Timing and Polarimetry mission—eXTP
2019
In this paper we present the enhanced X-ray Timing and Polarimetry mission - eXTP. eXTP is a space science mission designed to study fundamental physics under extreme conditions of density, gravity and magnetism. The mission aims at determining the equation of state of matter at supra-nuclear density, measuring effects of QED, and understanding the dynamics of matter in strong-field gravity. In addition to investigating fundamental physics, eXTP will be a very powerful observatory for astrophysics that will provide observations of unprecedented quality on a variety of galactic and extragalactic objects. In particular, its wide field monitoring capabilities will be highly instrumental to det…
The Modular X- and Gamma-Ray Sensor (MXGS)of the ASIM Payload on the International Space Station
2019
The Modular X- and Gamma-ray Sensor (MXGS) is an imaging and spectral X- and Gamma-ray instrument mounted on the starboard side of the Columbus module on the International Space Station. Together with the Modular Multi-Spectral Imaging Assembly (MMIA) (Chanrion et al. this issue) MXGS constitutes the instruments of the Atmosphere-Space Interactions Monitor (ASIM) (Neubert et al. this issue). The main objectives of MXGS are to image and measure the spectrum of X- and γ-rays from lightning discharges, known as Terrestrial Gamma-ray Flashes (TGFs), and for MMIA to image and perform high speed photometry of Transient Luminous Events (TLEs) and lightning discharges. With these two instruments sp…
Technology Impact on Neutron-Induced Effects in SDRAMs : A Comparative Study
2021
International audience; This study analyses the response of synchronous dynamic random access memories to neutron irradiation. Three different generations of the same device with different node sizes (63, 72, and 110 nm) were characterized under an atmospheric-like neutron spectrum at the ChipIr beamline in the Rutherford Appleton Laboratories, UK. The memories were tested with a reduced refresh rate to expose more single-event upsets and under similar conditions provided by a board specifically developed for this type of study in test facilities. The board has also been designed to be used as a nanosatellite payload in order to perform similar tests. The neutron-induced failures were studi…
Multicopter UAV design optimization
2014
Designing and selecting hardware for a multirotor can be challenging in order to get the best flight performance out of the system. In addition to selecting the hardware, the number of actuators can also be altered. For a 4 actuator (quadrotor) setup, one set of hardware can give the optimal design, while for a 6 actuator setup (hexarotor) the same hardware may not necessarily give the same response. In this paper we present a design optimization process of a multirotor, where the hardware is selected from a set of low-cost off-the-shelf standard RC hobby parts. Constraining the problem to a given hardware ensures existence of the selected hardware, and the design can be implemented. Also t…
Fluorescence explorer (FLEX): An optimised payload to map vegetation photosynthesis from space
2006
The FLuorescence EXplorer (FLEX) mission proposes to launch a satellite for the global monitoring of steady-state chlorophyll fluorescence in terrestrial vegetation. Fluorescence is a sensitive probe of photosynthetic function in both healthy and physiologically perturbed vegetation, and a powerful non-invasive tool to track the status, resilience, and recovery of photochemical processes and moreover provides important information on overall photosynthetic performance with implications for related carbon sequestration. The early responsiveness of fluorescence to atmospheric, soil and plant water balance, as well as to atmospheric chemistry and human intervention in land usage makes it an ob…
Modeling of Offshore Crane and Marine Craft in Wave Motion
2020
Safe handling of heavy payloads in an offshore environment requires careful planning and depends on the interaction between a crane and a vessel. This paper investigates the coupled dynamics between a multipurpose crane with payload, and an offshore carrying vessel. A classical multi-body model is derived using holonomic constraints and Newton-Euler kinetics. The resulting index-3 system of differential-algebraic equation (DAE) is transformed into an index-1 system and solved using commonly used numerical ode solvers. Numerical simulations are carried out to show that the proposed models behave in a physically realistic manner. © 2020 IEEE. Personal use of this material is permitted. Permis…