Search results for "RTK"
showing 10 items of 46 documents
The risk of hepatocellular carcinoma in HBV cirrhosis is affected by polymorphisms of the MERTK gene
2014
Rs4374383 single nucleotide polymorphism of MERTK gene influences the development of hepatocellular carcinoma (HCC) in patients with HCV cirrhosis
2013
A rs4374383 Single Nucleotide Polymorphisms of MERTK gene is linked to a higher likelihood of hepatocellular carcinoma in patients with HCV cirrhosis
2013
Determinazione della precisione e della ripetibilità in rilievi NRTK
2009
La sperimentazione descritta nel presente lavoro riguarda l’esecuzione di rilievi di una zona del territorio siciliano racchiusa all’interno della rete di nove stazioni permanenti GNSS ubicate nella Sicilia centro occidentale, ed in particolare nelle province di Palermo e di Trapani. Lo studio ha riguardato la definizione di una procedura per ottenere la ripetibilità delle misure su punti di coordinate note. Come già affrontato in altre sperimentazioni, si è fatto riferimento a punti appartenenti a reti ufficiali, come quelli della rete IGM95 e della Rete della Regione Siciliana. I risultati in termini di ripetibilità confermano le esperienze condotte in letteratura e cioè differenze di poc…
Uso delle tecniche GNSS a supporto dei rilievi di infortunistica stradale
2013
In the context of scientific research developed in recent years by DICAM, University of Palermo, a trend that is particularly interesting and multidisciplinary concerning the use of GNSS techniques in NRTK for applications of road accidents. The detections of the information relating to the left road today are conducted with standardized mode between those of local police; regarding the real relief it is realized with triangulation techniques, with the aid of manual instrumentation consists casters metrics in plastic or steel wires. The GNSS techniques in NRTK lend themselves well to this type of survey, the high information content and to manage different metadata (maps, coordinates, photo…
On the Accuracy of Cadastral Marks: Statistical Analyses to Assess the Congruence among GNSS-Based Positioning and Official Maps
2022
Cadastral marks constitute a dense source of information for topographical surveys required to update cadastral maps. Historically, in Italy, cadastral marks have been the cartographic network for the implementation of mapping updates. Different sources of cadastral marks can be used by cadastral surveyors. In recent years, the cadastre is moving toward a digital world, and with the advancement of surveying technology, GNSS CORS technology has emerged in the positioning of cadastral marks. An analysis of congruence among cadastral marks using GNSS CORS and official maps is missing. Thus, this work aims to analyze the positional accuracy of some cadastral marks, located in Palermo, Italy, wi…
The effects of cors network geometry and differential nrtk corrections on gnss solutions
2021
The widespread availability of Continuosly Operating Reference Station (CORS) all over the world, allows to improve more scientific and technical studies on the use of satellite positioning techniques. The aim of this paper is to understand the effects of a GNSS CORS network geometry and differential corrections on the solutions. The analysis is carried out using ten different network configurations, with different inter-distances between the stations within GNSMART Geo++ software. The coordinates of one control point placed on the top of the Department of Engineering (University of Palermo, Italy) have been used to perform several static positioning mode test within fourthy hours. Differen…
NRTK, PPP or Static, That Is the Question. Testing Different Positioning Solutions for GNSS Survey
2021
Worldwide, the determination of the coordinates from a Global Navigation Satellite System (GNSS) survey (in Network Real Time Kinematic, Precise Point Positioning, or static mode) has been analysed in several scientific and technical applications. Many of those have been carried out to compare Precise Point Positioning (PPP), Network Real Time Kinematic (NRTK), and static modes’ solutions, usually, using the latter as the true or the most plausible solution. This approach is not always possible as the static mode solution depends on several parameters (baseline length, acquisition time, ionospheric, and tropospheric models, etc.) that must be considered to evaluate the accuracy of the metho…
QR-Factorization Algorithm for Computed Tomography (CT): Comparison With FDK and Conjugate Gradient (CG) Algorithms
2018
[EN] Even though QR-factorization of the system matrix for tomographic devices has been already used for medical imaging, to date, no satisfactory solution has been found for solving large linear systems, such as those used in computed tomography (CT) (in the order of 106 equations). In CT, the Feldkamp, Davis, and Kress back projection algorithm (FDK) and iterative methods like conjugate gradient (CG) are the standard methods used for image reconstruction. As the image reconstruction problem can be modeled by a large linear system of equations, QR-factorization of the system matrix could be used to solve this system. Current advances in computer science enable the use of direct methods for…
Performance assessment of PPP surveys with open source software using the GNSS GPS-GLONASS-Galileo constellations
2020
In this work, the performance of the multi-GNSS (Global Navigation Satellite System) Precise Point Positioning (PPP) technique, in static mode, is analyzed. Specifically, GPS (Global Positioning System), GLONASS, and Galileo systems are considered, and quantifying the Galileo contribution is one of the main objectives. The open source software RTKLib is adopted to process the data, with precise satellite orbits and clocks from CNES (Centre National d&rsquo