134 research outputs found

    A low cost mobile mapping system (LCMMS) for field data acquisition: a potential use to validate aerial/satellite building damage assessment

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    Among the major natural disasters that occurred in 2010, the Haiti earthquake was a real turning point concerning the availability, dissemination and licensing of a huge quantity of geospatial data. In a few days several map products based on the analysis of remotely sensed data-sets were delivered to users. This demonstrated the need for reliable methods to validate the increasing variety of open source data and remote sensing-derived products for crisis management, with the aim to correctly spatially reference and interconnect these data with other global digital archives. As far as building damage assessment is concerned, the need for accurate field data to overcome the limitations of both vertical and oblique view satellite and aerial images was evident. To cope with the aforementioned need, a newly developed Low-Cost Mobile Mapping System (LCMMS) was deployed in Port-au-Prince (Haiti) and tested during a five-day survey in FebruaryMarch 2010. The system allows for acquisition of movies and single georeferenced frames by means of a transportable device easily installable (or adaptable) to every type of vehicle. It is composed of four webcams with a total field of view of about 180 degrees and one Global Positioning System (GPS) receiver, with the main aim to rapidly cover large areas for effective usage in emergency situations. The main technical features of the LCMMS, the operational use in the field (and related issues) and a potential approach to be adopted for the validation of satellite/aerial building damage assessments are thoroughly described in the articl

    A reference data access service in support of emergency management

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    In the field of natural disasters recovery and reduction and of emergency management georeferenced information is strongly needed. In my personal experience obtained in the three years period spent at ITHACA, during the shorter at GFDRR Labs and through the work done indirectly with UN-WFP, after a natural disaster occurs, the experts in geomatics are often asked to provide answers to questions such as: where did it occur? How many people have been involved? How many infrastructures have been damaged and to what extent? How much is the economical loss? Geomatics can give answer to all these questions or give significant help in addressing operations in order to get the answers. The goal can be reached both with the use of base reference data, the ones usually contained in the classic cartography, and by exploiting value added information coming from satellite and aerial data processing, classic surveys and GPS acquisition on the fiel

    a quality comparison between professional and crowdsourced data in emergency mapping for potential cooperation of the services

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    ABSTRACTA protocol for assessing the quality of digital geospatial data is applied to samples of volunteered geographic information (created by Humanitarian OpenStreetMap Team) and professional mappers (Copernicus EMS-rapid mapping). The application on pre-event data shows that a large percentage of them is very similar in terms of quality and is, therefore, potentially interchangeable; post-event data reveal a more divergent behaviour. The results gathered from the comparative analysis and a look at the temporal trends of response of volunteers and professionals justify a framework of interaction of respective activities, which seems to be possible under strong relationship between professionals and volunteers, built upon common operational standards and guidelines

    Improving an Extreme Rainfall Detection System with GPM IMERG data

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    Many studies have shown a growing trend in terms of frequency and severity of extreme events. As never before, having tools capable to monitor the amount of rain that reaches the Earth’s surface has become a key point for the identification of areas potentially affected by floods. In order to guarantee an almost global spatial coverage, NASA Global Precipitation Measurement (GPM) IMERG products proved to be the most appropriate source of information for precipitation retrievement by satellite. This study is aimed at defining the IMERG accuracy in representing extreme rainfall events for varying time aggregation intervals. This is performed by comparing the IMERG data with the rain gauge ones. The outcomes demonstrate that precipitation satellite data guarantee good results when the rainfall aggregation interval is equal to or greater than 12 h. More specifically, a 24-h aggregation interval ensures a probability of detection (defined as the number of hits divided by the total number of observed events) greater than 80%. The outcomes of this analysis supported the development of the updated version of the ITHACA Extreme Rainfall Detection System (ERDS: erds.ithacaweb.org). This system is now able to provide near real-time alerts about extreme rainfall events using a threshold methodology based on the mean annual precipitation

    Clinical Features, Cardiovascular Risk Profile, and Therapeutic Trajectories of Patients with Type 2 Diabetes Candidate for Oral Semaglutide Therapy in the Italian Specialist Care

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    Introduction: This study aimed to address therapeutic inertia in the management of type 2 diabetes (T2D) by investigating the potential of early treatment with oral semaglutide. Methods: A cross-sectional survey was conducted between October 2021 and April 2022 among specialists treating individuals with T2D. A scientific committee designed a data collection form covering demographics, cardiovascular risk, glucose control metrics, ongoing therapies, and physician judgments on treatment appropriateness. Participants completed anonymous patient questionnaires reflecting routine clinical encounters. The preferred therapeutic regimen for each patient was also identified. Results: The analysis was conducted on 4449 patients initiating oral semaglutide. The population had a relatively short disease duration (42%  60% of patients, and more often than sitagliptin or empagliflozin. Conclusion: The study supports the potential of early implementation of oral semaglutide as a strategy to overcome therapeutic inertia and enhance T2D management

    Performance update of an event-type based analysis for the Cherenkov Telescope Array

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    The Cherenkov Telescope Array (CTA) will be the next-generation observatory in the field of very-high-energy (20 GeV to 300 TeV) gamma-ray astroparticle physics. The traditional approach to data analysis in this field is to apply quality cuts, optimized using Monte Carlo simulations, on the data acquired to maximize sensitivity. Subsequent steps of the analysis typically use the surviving events to calculate one set of instrument response functions (IRFs) to physically interpret the results. However, an alternative approach is the use of event types, as implemented in experiments such as the Fermi-LAT. This approach divides events into sub-samples based on their reconstruction quality, and a set of IRFs is calculated for each sub-sample. The sub-samples are then combined in a joint analysis, treating them as independent observations. In previous works we demonstrated that event types, classified using Machine Learning methods according to their expected angular reconstruction quality, have the potential to significantly improve the CTA angular and energy resolution of a point-like source analysis. Now, we validated the production of event-type wise full-enclosure IRFs, ready to be used with science tools (such as Gammapy and ctools). We will report on the impact of using such an event-type classification on CTA high-level performance, compared to the traditional procedure

    Expected exclusion limits to TeV dark matter from the Perseus Cluster with the Cherenkov Telescope Array

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    Clusters of galaxies are the largest gravitationally-bound structures in the Universe. They are composed of galaxies and gas (approximately 15% of the total mass) mostly dark matter (DM, accounts up to 85% of the total mass). If the DM is composed of Weakly Interacting Massive Particles (WIMPs), galaxy clusters represent one of the best targets to search for gamma-ray signals induced by the decay of WIMPs, with masses around the TeV scale. Due to its sensitivity and energy range of operation (from 20 GeV to 300 TeV), the Cherenkov Telescope Array (CTA) Observatory has a unique opportunity to test WIMPs with masses close to the unitarity limit. This will complement the searches for DM from other gamma-ray observatories as well as direct and collider experiments. The CTA Observatory is planning to search for gamma-ray emission, either its origin may be cosmic-ray (CR) or DM related, in the Perseus galaxy cluster during the first years of operation. In this poster, we will present the software created to perform the analysis using the ctools software and the corresponding results

    Chasing Gravitational Waves with the Cherenkov Telescope Array

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    The detection of gravitational waves (GWs) from a binary neutron star (BNS) merger by Advanced LIGO and Advanced Virgo (GW170817), along with the discovery of the electromagnetic counterparts of this GW event, ushered in a new era of multimessenger astronomy, providing the first direct evidence that BNS mergers are progenitors of short gamma-ray bursts (GRBs). Such events may also produce very-high-energy (VHE, > 100GeV) photons which have yet to be detected in coincidence with a GW signal. The Cherenkov Telescope Array (CTA) is a next-generation VHE observatory which aims to be indispensable in this search, with an unparalleled sensitivity and ability to slew anywhere on the sky within a few tens of seconds. Achieving such a feat will require a comprehensive real-time strategy capable of coordinating searches over potentially very large regions of the sky. This work will evaluate and provide estimations on the number of GW-CTA events determined from simulated BNS systems and short GRBs, considering both on- and off-axis emission. In addition, we will present and discuss the prospects of potential follow-up strategies with CTA
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