116,920 research outputs found

    Design of a Low-cost and Compact Radiometer for Spectral Acquisition of Vegetation and Bare Soil

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    We describe, in this article, the design of a low-cost and compact radiometer with five analog channels for spectral acquisition: four in the visible (blue, green, red and panchromatic) and one channel in the near-infrared. This small embedded system is based on an 8-bit microcontroller for automatic data acquisition, calibrating, storing and serial link processing with a compatible PC, through a C++ application software provided to handle and deal with the mass of data collected and stored in an EEPROM. The acquisition of spectral reflectance measurements of an object for different wavelengths allows the construction of a characteristic curve, named spectral signature of the object. The study of the spectral signatures of different types of surfaces such as water, bare ground or vegetation allows their identification in remote sensing image processing, and consequently, facilitates the interpretation of this kind of data, as, for instance, the AVHRR data of the HRPT images acquired and freely distributed by the satellite NOAA

    Design of a Low-cost and Compact Radiometer for Spectral Acquisition of Vegetation and Bare Soil

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    We describe, in this article, the design of a low-cost and compact radiometer with five analog channels for spectral acquisition: four in the visible (blue, green, red and panchromatic) and one channel in the near-infrared. This small embedded system is based on an 8-bit microcontroller for automatic data acquisition, calibrating, storing and serial link processing with a compatible PC, through a C++ application software provided to handle and deal with the mass of data collected and stored in an EEPROM. The acquisition of spectral reflectance measurements of an object for different wavelengths allows the construction of a characteristic curve, named spectral signature of the object. The study of the spectral signatures of different types of surfaces such as water, bare ground or vegetation allows their identification in remote sensing image processing, and consequently, facilitates the interpretation of this kind of data, as, for instance, the AVHRR data of the HRPT images acquired and freely distributed by the satellite NOAA

    Evaluation of MILS and reduced kernel security concepts for SCADA remote terminal units.

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    The purpose of this project is to study the benefits that the Multiple Independent Levels of Security (MILS) approach can provide to Supervisory Control and Data Acquisition (SCADA) remote terminal units. This is accomplished through a heavy focus on MILS concepts such as resource separation, verification, and kernel minimization and reduction. Two architectures are leveraged to study the application of reduced kernel concepts for a remote terminal unit (RTU). The first is the LynxOS embedded operating system, which is used to create a bootable image of a working RTU. The second is the Pistachio microkernel, the features and development environment of which are analyzed and catalogued to provide the basis for a future RTU. A survey of recent literature is included that focuses on the state of SCADA security, the MILS standard, and microkernel research. The design methodology for a MILS compliant RTU is outlined, including a benefit analysis of applying MILS in an industrial network setting. Also included are analyses of the concepts of MILS which are relevant to the design and how LynxOS and Pistachio can be used to study some of these concepts. A section detailing the prototyping of RTUs on LynxOS and Pistachio is also included, followed by an initial security and performance analysis for both systems

    Bridges Structural Health Monitoring and Deterioration Detection Synthesis of Knowledge and Technology

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    INE/AUTC 10.0

    UNICS - An Unified Instrument Control System for Small/Medium Sized Astronomical Observatories

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    Although the astronomy community is witnessing an era of large telescopes, smaller and medium sized telescopes still maintain their utility being larger in numbers. In order to obtain better scientific outputs it is necessary to incorporate modern and advanced technologies to the back-end instruments and to their interfaces with the telescopes through various control processes. However often tight financial constraints on the smaller and medium size observatories limit the scope and utility of these systems. Most of the time for every new development on the telescope the back-end control systems are required to be built from scratch leading to high costs and efforts. Therefore a simple, low cost control system for small and medium size observatory needs to be developed to minimize the cost and efforts while going for the expansion of the observatory. Here we report on the development of a modern, multipurpose instrument control system UNICS (Unified Instrument Control System) to integrate the controls of various instruments and devices mounted on the telescope. UNICS consists of an embedded hardware unit called Common Control Unit (CCU) and Linux based data acquisition and User Interface. The Hardware of the CCU is built around the Atmel make ATmega 128 micro-controller and is designed with a back-plane, Master Slave architecture. The Graphical User Interface (GUI) has been developed based on QT and the back end application software is based on C/C++. UNICS provides feedback mechanisms which give the operator a good visibility and a quick-look display of the status and modes of instruments. UNICS is being used for regular science observations since March 2008 on 2m, f/10 IUCAA Telescope located at Girawali, Pune India.Comment: Submitted to PASP, 10 Pages, 5 figure

    TU1208 open database of radargrams. the dataset of the IFSTTAR geophysical test site

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    This paper aims to present a wide dataset of ground penetrating radar (GPR) profiles recorded on a full-size geophysical test site, in Nantes (France). The geophysical test site was conceived to reproduce objects and obstacles commonly met in the urban subsurface, in a completely controlled environment; since the design phase, the site was especially adapted to the context of radar-based techniques. After a detailed description of the test site and its building process, the GPR profiles included in the dataset are presented and commented on. Overall, 67 profiles were recorded along eleven parallel lines crossing the test site in the transverse direction; three pulsed radar systems were used to perform the measurements, manufactured by different producers and equipped with various antennas having central frequencies from 200 MHz to 900 MHz. An archive containing all profiles (raw data) is enclosed to this paper as supplementary material. This dataset is the core part of the Open Database of Radargrams initiative of COST (European Cooperation in Science and Technology) Action TU1208 “Civil engineering applications of Ground Penetrating Radar”. The idea beyond such initiative is to share with the scientific community a selection of interesting and reliable GPR responses, to enable an effective benchmark for direct and inverse electromagnetic approaches, imaging methods and signal processing algorithms. We hope that the dataset presented in this paper will be enriched by the contributions of further users in the future, who will visit the test site and acquire new data with their GPR systems. Moreover, we hope that the dataset will be made alive by researchers who will perform advanced analyses of the profiles, measure the electromagnetic characteristics of the host materials, contribute with synthetic radargrams obtained by modeling the site with electromagnetic simulators, and more in general share results achieved by applying their techniques on the available profiles

    Embedded Sensor System for Early Pathology Detection in Building Construction

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    Structure pathology detection is an important security task in building construction, which is performed by an operator by looking manually for damages on the materials. This activity could be dangerous if the structure is hidden or difficult to reach. On the other hand, embedded devices and wireless sensor networks (WSN) are becoming popular and cheap, enabling the design of an alternative pathology detection system to monitor structures based on these technologies. This article introduces a ZigBee WSN system, intending to be autonomous, easy to use and with low power consumption. Its functional parts are fully discussed with diagrams, as well as the protocol used to collect samples from sensor nodes. Finally, several tests focused on range and power consumption of our prototype are shown, analysing whether the results obtained were as expected or not
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