48 research outputs found

    METODO PER LA STIMA DI PRESENZA DI PIOGGIA

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    La presente invenzione ha per oggetto un metodo per la stima di presenza di pioggia del tipo precisato nel preambolo della prima rivendicazione. In particolare, la presente invenzione ha per oggetto un metodo per la stima di presenza di pioggia basato sulla misura della degradazione del segnale sulla tratta in discesa di collegamenti satellitari con regolazione adattiva dei parametri atmosferici di riferimento

    Design of a modular Autonomous Underwater Vehicle for archaeological investigations

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    MARTA (MARine Tool for Archaeology) is a modular AUV (Autonomous Underwater Vehicle) designed and developed by the University of Florence in the framework of the ARROWS (ARchaeological RObot systems for the World's Seas) FP7 European project. The ARROWS project challenge is to provide the underwater archaeologists with technological tools for cost affordable campaigns: i.e. ARROWS adapts and develops low cost AUV technologies to significantly reduce the cost of archaeological operations, covering the full extent of an archaeological campaign (underwater mapping, diagnosis and cleaning tasks). The tools and methodologies developed within ARROWS comply with the "Annex" of the 2001 UNESCO Convention for the protection of Underwater Cultural Heritage (UCH). The system effectiveness and MARTA performance will be demonstrated in two scenarios, different as regards the environment and the historical context, the Mediterranean Sea (Egadi Islands) and the Baltic Sea

    The ARROWS project: Adapting and developing robotics technologies for underwater archaeology

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    ARchaeological RObot systems for the World's Seas (ARROWS) EU Project proposes to adapt and develop low-cost Autonomous Underwater Vehicle (AUV) technologies to significantly reduce the cost of archaeological operations, covering the full extent of archaeological campaign. ARROWS methodology is to identify the archaeologists requirements in all phases of the campaign and to propose related technological solutions. Starting from the necessities identified by archaeological project partners in collaboration with the Archaeology Advisory Group, a board composed of European archaeologists from outside ARROWS, the aim is the development of a heterogeneous team of cooperating AUVs capable of comply with a complete archaeological autonomous mission. Three new different AUVs have been designed in the framework of the project according to the archaeologists' indications: MARTA, characterized by a strong hardware modularity for ease of payload and propulsion systems configuration change; U-C AT, a turtle inspired bio-mimetic robot devoted to shipwreck penetration and A-Size AUV, a vehicle of small dimensions and weight easily deployable even by a single person. These three vehicles will cooperate within the project with AUVs already owned by ARROWS partners exploiting a distributed high-level control software based on the World Model Service (WMS), a storage system for the environment knowledge, updated in real-time through online payload data process, in the form of an ontology. The project includes also the development of a cleaning tool for well-known artifacts maintenance operations. The paper presents the current stage of the project that will lead to overall system final demonstrations, during Summer 2015, in two different scenarios, Sicily (Italy) and Baltic Sea (Estonia

    Carrier Frequency Recovery in All-Digital Modems for Burst-Mode Transmissions

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    Reliable data detection in time division multiple access (TDMA) communication systems strictly depends on the availability of accurate estimates of the synchronization parameters of the received signal, i.e., carrier frequency/phase and symbol timing, which must be derived from the burst preamble. The authors focus on the carrier frequency estimation aspect, and present a fast, open-loop, all-digital frequency offset estimation technique, whose performance is assessed in two different communication scenarios: a TDMA satellite link employing standard modulation and burst formats, and a mobile cellular terrestrial radio system with signal and channel characteristics obeying the pan-European Group Special Mobile (GSM) recommendations. The use of the algorithm as a frequency error detector (discriminator) in a recursive ("closed-loop") frequency offset estimator is also discussed, and some results concerning both the transient and the steady-state behavior of such a scheme are presented. Finally, the impact of the algorithm on the receiver BER is briefly analyzed

    Frequency recovery for filter-bank multicarrier transmission on doubly-selective fading channels

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    In this paper we deal with carrier frequency estimation for filter-bank multicarrier burst transmission over time-frequency selective fading channels. Three open-loop algorithms are discussed, all based on the use of known pilot symbols. The first scheme is derived from the maximum likelihood principle, while the second one consists of its low-SNR approximation, and both of them require knowledge of the fading covariance matrix. The third scheme is ad-hoc and is based on the well-known delay-multiply concept. Theoretical analysis and simulation results are employed to assess the above algorithms in a time-frequency selective mobile wireless scenario
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