1,721,059 research outputs found
Premio AUTeC per la migliore Tesi di Dottorato in Cartografia e Topografia
No full textThis is the result of three years of work and research around GNSS permanent stations and
Networks, GNSS data processing and GNSS surveys technics and methodologies for several
applications.
It is possible to associate the main field of the research to the two main goals of GNSS
Networks: Realize a Reference system and distribute it to the users community.
Earth surface is continuously changing due to several phenomena, which may be
distinguished in periodic and irreversible phenomena.
With respect to periodic phenomena a mean position of a point on Earth surface can be
defined. With respect to irreversible phenomena each point occupies a specific position just
for an infinitesimal instant: estimated coordinates of a point (spatial referencing) must be also
time referenced.
A Reference System (RS) is, at first, defined by mathematical/physical laws rules. Then, a
realization (Reference Frame, RF) follows, by physical and geometrical measurements.
Terrestrial reference systems are needed to georeference the positions of points located on the
Earth. They can be distinguished in:
· Global Reference Systems
They are defined on the whole planet and realized by global networks of fundamental
points. Fundamental points coordinates are estimated by spatial geodesy techniques.
· Local Reference Systems
They are defined at the local scale (continental or regional) and realized by
subnetworks of fundamental points. Fundamental points coordinates are estimated by
terrestrial geodesy techniques. In this category is possible to mention the ED1950 (for
Europe) and ROMA1940 (for Italy).
Local reference systems, since they born before spatial geodesy, are nowadays decreasing of
importance in terms of points georeferencing, but they still have historical significance and
are used in cartographic applications.
After the birth of spacial geodesy, like GNSS (Global Navigation Satellite System), it was
possible to define and realize global reference systems. The nodal point of this innovation is
the realization of the global reference system by GNSS permanent stations networks.
During the Ph.D. activities a deep analysis of global reference systems research was carried
out. In particular, GNSS data processing techniques and skills were acquired. This aspect of
the research achieved the goal with the author involvement, as Geodesy and Geomatics
Group member, into the realization by the Italian Military Geographic Institute (IGM) of the
European Reference System in Italy. The switch form the old static realization (IGM95) to a
GNSS permanent station based realization was made official and published by IGM in
February 2009 with the National Dynamic Network (RDN) presentation: 100 GNSS
permanent stations homogenously distributed in the Italian Country.
Also the official permanent station of the La Sapienza Rome University, M0SE, of which
maintenance and inclusion in the European Permanent networ
GNSS Permanent Stations Networks for Positioning Services
No full textRicerca di Dottorato vincitrice del Premio AUTeC 200
La rete permanente GNSS della Regione Lazio: un'infrastruttura innovativa a servizio dell'e-government
No full textSISTEMA DI MISURA DI MOVIMENTI IN TEMPO REALE, IN PARTICOLARE DI MOVIMENTI COSISMICI E DI VIBRAZIONI DI STRUTTURE
No full textVariometric approach for real-time GNSS navigation: First demonstration of Kin-VADASE capabilities
No full textThe use of Global Navigation Satellite Systems (GNSS) kinematic positioning for navigational applications dramatically increased over the last decade. Real-time high performance navigation (positioning accuracy from one to few centimeters) can be achieved with established techniques such as Real Time Kinematic (RTK), and Precise Point Positioning (PPP). Despite their potential, the application of these techniques is limited mainly by their high cost. This work proposes the Kinematic implementation of the Variometric Approach for Displacement Analysis Standalone Engine (Kin-VADASE) and gives a demonstration of its performances in the field of GNSS navigation. VADASE is a methodology for the real-time detection of a standalone GNSS receiver displacements. It was originally designed for seismology and monitoring applications, where the receiver is supposed to move for few minutes, in the range of few meters, around a predefined position. Kin-VADASE overcomes the aforementioned limitations and aims to be a complete methodology with fully kinematic capabilities. Here, for the first time, we present its application to two test cases in order to estimate high rate (i.e., 10 Hz) kinematic parameters of moving vehicles. In this demonstration, data are collected and processed in the office, but the same results can be obtained in real-time through the implementation of Kin-VADASE in the firmware of a GNSS receiver. All the Kin-VADASE processing were carried out using double and single frequency observations in order to investigate the potentialities of the software with geodetic class and low-cost single frequency receivers. Root Mean Square Errors in 3D with respect to differential positioning are at the level of 50 cm for dual frequency and better than 1 meter for single frequency data. This reveals how Kin-VADASE features the main advantage of the standalone approach and the single frequency capability and, although with slightly lower accuracy with respect to the established techniques, can be a valid alternative to estimate kinematic parameters of vehicle in motions
Determinazione delle quote ortometriche nel sistema altimetrico nazionale (Mareografo di Genova) delle origini (zeri idrometrici) di 59 idrometri situati nel territorio della Regione Lazio
No full textCompensazione della Rete Dinamica Nazionale dell’Istituto Geografico Militare Italiano: Procedure e risultati ottenuti dal Gruppo G3
No full textSessione Speciale RD
European Satellite Navigation Competition 2010 - Audience Award
No full text*** DESCRIPTION *** This is a novel strategy consisting of an algorithm able to perform real-time retrieval and estimation of displacement and waveforms based on high-frequency (1Hz or more) carrier phase observations collected by a stand-alone GNSS receiver.
The algorithm works with broadcast products (satellite clocks and orbits) and requires very simple hardware. These characteristics allow our solution to be directly embedded into receiver firmware and permit to estimate, in realtime and without any need for corrections from other sources, the receiver displacements.
Although such an ingenious idea can be applied to several different problems, we focus on two we believe are most important: earthquake risk assessment (and related early-warning systems for tsunamis) and structural monitoring. *** INNOVATION *** The major advancement of the proposed solution introduces a novel strategy in performing real-time estimation of coseismic displacement and waveforms accurate down to a few centimetres. Given the fact that it requires no centralised data analysis, no external corrections for the algorithm to work, and no particularly powerful hardware, the solution can be embedded directly into receiver firmware. This framework enables VADASE to fulfill some of the recommendations recently adopted by the scientific community (2007, Leavenworth) – in particular, the possibility to achieve 1-cm real-time GNSS displacement accuracy in a global reference frame within three minutes after an earthquake.
*** TARGET MARKET *** The immediate fields of application include high-frequency real-time monitoring in seismology and tsunami early-warning systems, as well as the monitoring of structures and geotechnical engineering; oscillation monitoring for different types of structures (buildings, skyscrapers, dams, etc); and safety monitoring for infrastructure elements (railways, highways, etc) close to potential hazard (landslides, etc).
*** CUSTOMER BENEFIT *** Public administrations in charge of surveying and monitoring areas susceptible to earthquakes or tsunamis, as well as all civil protection departments responsible for monitoring infrastructures that experience oscillations, can take advantage of this idea. In particular, the real-time capability of the system – together with the possibility to embed VADASE into existing sensors’ firmware – makes it a low-cost monitoring solution. In fact, the system is completely self-reliant and needs no additional network infrastructure
Global and local reference frames
No full textThe goal of this review paper is to recall the concept of geodetic reference frame, showing its intrinsic dependence from all the information and choices related to its realization, and to discuss the still alive distinction between "global'' and "local'' reference frames, considering the unbreakable link between Geodesy and Geophysics. An up-to-date review of the most relevant presently adopted global and local (in this respect, mainly at European and Italian level) reference frames is presented. Finally, some conclusions and still open problems, related to the current research, are outlined
- …
