1,797 research outputs found
Scan to BIM for 3D reconstruction of the papal basilica of saint Francis in Assisi In Italy
The historical building heritage, present in the most of Italian cities centres, is, as part of the construction sector, a working potential,
but unfortunately it requires planning of more complex and problematic interventions. However, policies to support on the existing
interventions, together with a growing sensitivity for the recovery of assets, determine the need to implement specific studies and to
analyse the specific problems of each site. The purpose of this paper is to illustrate the methodology and the results obtained from
integrated laser scanning activity in order to have precious architectural information useful not only from the cultural heritage point
of view but also to construct more operative and powerful tools, such as BIM (Building Information Modelling) aimed to the
management of this cultural heritage. The Papal Basilica and the Sacred Convent of Saint Francis in Assisi in Italy are, in fact,
characterized by unique and complex peculiarities, which require a detailed knowledge of the sites themselves to ensure visitor’s
security and safety. For such a project, we have to take in account all the people and personnel normally present in the site, visitors
with disabilities and finally the needs for cultural heritage preservation and protection. This aim can be reached using integrated
systems and new technologies, such as Internet of Everything (IoE), capable of connecting people, things (smart sensors, devices and
actuators; mobile terminals; wearable devices; etc.), data/information/knowledge and processes to reach the desired goals. The IoE
system must implement and support an Integrated Multidisciplinary Model for Security and Safety Management (IMMSSM) for the
specific context, using a multidisciplinary approach
Assessment of dual frequency GNSS observations from a Xiaomi Mi 8 android smartphone and positioning performance analysis
On May 2018 the world’s first dual-frequency Global Navigation Satellite System (GNSS) smartphone produced by Xiaomi equipped with a Broadcom BCM47755 chip was launched. It is able to receive L1/E1/ and L5/E5 signals from GPS, Galileo, Beidou, and GLONASS (GLObal NAvigation Satellite System) satellites. The main aim of this work is to achieve the phone’s position by using multi-constellation, dual frequency pseudorange and carrier phase raw data collected from the smartphone. Furthermore, the availability of dual frequency raw data allows to assess the multipath performance of the device. The smartphone’s performance is compared with that of a geodetic receiver. The experiments were conducted in two different scenarios to test the smartphone under different multipath conditions. Smartphone measurements showed a lower C/N0 and higher multipath compared with those of the geodetic receiver. This produced negative effects on single-point positioning as showed by high root mean square error (RMS). The best positioning accuracy for single point was obtained with the E5 measurements with a DRMS (horizontal root mean square error) of 4.57 m. For E1/L1 frequency, the 2DRMS was 5.36 m. However, the Xiaomi Mi 8, thanks to the absence of the duty cycle, provided carrier phase measurements used for a static single frequency relative positioning with an achieved 2DRMS of 1.02 and 1.95 m in low and high multipath sites, respectively
Studio delle possibilità di utilizzo della costellazione Glonass nel suo stato
GLONASS (Global Navigation Satellite System) is a global position satellite system realized by ex-
Urss at the same time with the United State’s one. The first launch of satellites went back to 12th
October 1982, they completed constellation with 24 satellites in 1997. In the years Russia didn’t
have economic force to maintain active the entire constellation. But in 2002 GLONASS relaunching
started, that provides 18 satellites before 2007, and it will reach 24 satellites before 2010. The
program provides the launch of three or two rockets a year, each one will bring to space two or three
satellite. At present (15th September 2006) there are 15 operative GLONASS satellites.
The aim of this work is to show the potentiality of the jointed use of GPS and GLONASS satellites
by performing an adequate subdivision of the observations collected during a survey in the area of
Rome using TOPCON receivers able to acquire data coming from both constellations
First considerations on post processing kinematic GNSS data during a geophysical oceanographic cruise
Differential GNSS positioning on vessels is of considerable interest in various fields of application as navigation aids, precision positioning for geophysical surveys or sampling purposes especially when high resolution bathymetric surveys are conducted. However ship positioning must be considered a kinematic survey with all the associated problems. The possibility of using high-precision differential GNSS receivers in navigation is of increasing interest, also due to the very recent availability of low-cost differential receivers that may soon replace classic navigation ones based on the less accurate point positioning technique. The availability of greater plano-altimetric accuracy, however, requires an increasingly better understanding of planimetric and altimetric reference systems. In particular, the results allow preliminary considerations on the congruence between terrestrial reference systems (which the GNSS survey can easily refer to) and marine reference systems (connected to National Tidegauge Network). In spite of the fluctuations due to the physiological continuous variation of the ship's attitude, GNSS plot faithfully followed the trend of the tidal variations and highlighted the shifts between GNSS plot and the tide gauges due to the different materialization of the relative reference systems
APPLICABIILITA’ DELL’APPROCCIO MULTICOSTELLATION CON L’AUSILIO DI SOFTWARE COMMERCIALI NELLA RETE UNIPA
Lo sviluppo dei sistemi di radio navigazione satellitare richiede lo studio di soluzioni nuove, in particolar modo per quanto riguarda l'integrazione di più sistemi satellitari. In numerosi lavori è stata studiata l'influenza che l'utilizzo congiunto dei sistemi satellitari GLONASS e GPS hanno in un rilievo topografico.
Tuttavia, scopo di questo articolo scientifico non è tanto quello di valutare questa influenza, ma di dare un forte apporto allo sviluppo di un nuova metodologia, del tutto innovativa, denominata Multiconstellation. L'approccio Multiconstellation, come è noto in letteratura, è stato introdotto qualche anno or sono dai ricercatori dell'area Geomatica dell'Università La Sapienza di Roma; da allora sono stati compiuti alcuni lavori con tale approccio con sessioni limitata ad una durata di 30 minuti, su basi di lunghezza minima.
Con questo nuovo metodo, modificando i files RINEX originali mediante l'utilizzo del software Multicon, è possibile raddoppiare il numero di basi linearmente indipendenti per sessione, dimezzando pertanto il numero di sessioni da utilizzare e quindi il tempo necessario per eseguire l'intero rilievo. Considerando che nella pratica professionale un topografo utilizza spesso strumenti noleggiati e software commerciali per le elaborazioni dei dati, dimezzare i tempi complessivi di un rilevo implica diminuire i costi complessivi dello stesso. Essendo quindi evidenti i vantaggi teorici di questo nuovo approccio rispetto a quello tradizionale, si è pensato di valutare la sua affidabilità in termini di precisioni raggiungibili con sessioni di durata più lunga di quelle utilizzate negli anni scorsi, cioè con durata temporale estesa tra le 3 e le 12 ore, considerando i dati provenienti dalla rete sperimentale gestita dal DICAM dell’Università di Palermo, mediante l’utilizzo dei principali software commerciali delle più prestigiose case produttrici mondiali (Leica LGO ver.8,0, Topcon Pinnacle ver 1.0, Topcon Tools ver. 8.0, Trimble Business Center)
Multiple primary malignancies of the liver and the colon: a complex diagnostic and decisional process with a final unanswered question
We herein present the case of a 78-year-old man with an incidental finding of a solid hepatic mass without symptoms and only a laparotomic cholecystectomy for acute cholecystitis in the past surgical history. A colonoscopy, a magnetic resonance imaging scan, a positron emission tomography scan, and a computed tomography scan completed the preoperative workup: a neoplastic lesion 4.3 × 3 cm in size was diagnosed at segments IV and V, associated with a neoplastic involvement of the splenic flexure without signs of colonic occlusion. After colonic resection, a frozen section on a granulomatous-like tissue at gastric border suggested a diagnosis of an adenocarcinoma of bilio-pancreatic type, changing the surgical strategy to include gastric resection and hepatic pedicle node dissection. The discussion turns around the idea that a final diagnosis of colon cancer with regional nodal involvement (pT3N1) and metastatic gallbladder cancer with multiple peritoneal seedings cannot be excluded
Water level and volume estimations of the Albano and Nemi lakes (central Italy)
In April 2006 an airborne laser scanning (LIDAR) survey of the Albano and Nemi craters was carried out to obtain
a high resolution digital terrain model (DTM) of the area. We have integrated the LIDAR survey of the
craters and the recent bathymetry of the Albano lake to achieve a complete DTM, useful for morphological studies.
In addition, with a GPS RTK survey (July 2007) we estimated the Albano and Nemi mean lake levels respectively
at 288.16 m and 319.02 m (asl). Based on the integrated DTM and the newly estimated water level
values, we evaluated about 21.7·106 m3 the water volume loss of the Albano lake from 1993 to 2007, with an
average rate of about 1.6·106 m3/yr
Precise point positioning with single and dual-frequency multi-GNSS android smartphones
The new generation of Android smartphones is equipped with high performance Global Navigation Satellite System (GNSS) chips capable of tracking dual frequency multi-constellation data. Moreover, starting from version 9 of Android users can disable the duty cycle power saving option thus good quality pseudorange and carrier phase raw data are available thus the application of Precise Point Positioning (PPP) algorithm becomes more and more interesting. The main aim of this work is to assess the PPP performance of the first dual-frequency GNSS smartphone produced by Xiaomi equipped with a Broadcom BCM47755. The advantage of acquire dual frequency data is highlighted by comparing the performance obtained by Xiaomi with that of a single frequency smartphone the Samsung S8. The horizontal and vertical accuracy achieved by Xiaomi are of 0.51 m and 6 m respectively while those achieved by Samsung are 5.64 m for 15 m for horizontal and vertical
Gunshot wound without entrance hole: where is the trick? - a case report and review of the literature
The presence at CT scan of more retained bullets than expected could be a very difficult interpretation challenge in the early management of gunshot wounds. The modern non operative management of haemodinamically stable patients without peritonitis requires that the trajectory of the bullet is clearly recognized. This clinical case reporting of a gunshot wound without evident entry hole, allows to discuss the diagnostic and therapeutic implications in the management of gunshot wounds cases with atypical entry and/or exit holes
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