Search results for "Gnss"
showing 10 items of 88 documents
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…
Rilievo di un parco urbano con integrazione delle tecniche GNSS, NRTK, Laser Scanner e MMS
2013
Questo articolo riassume l'esperienza dei ricercatori del Dipartimento di Ingegneria Civile, Ambientale, Aerospaziale, dei Materiali (DICAM) dell'Università di Palermo nell'ambito del rilievo di un parco urbano e la sperimentazione di strumenti, tecniche e metodi innovativi. Da piu di vent'anni il Parco d'Orleans, adiacente il campus Universitario di Palermo, rappresenta un laboratorio all'interno del quale effettuare sperimentazioni di alto livello scientifico. Recentemente, una parte di questo parco è stato intitolato alla memoria di Ninni Cassarà, vice questore della Polizia di Stato e collaboratore di Giovanni Falcone. Esso si estende lungo la parte della campagna palermitana che va dal…
A software receiver phase lock loop analysis and design to implement adaptive phase tracking using a finite impulse response loop filter
2009
In this paper we analyze the design of a digital Phase Lock Loop (PLL) for a Global Navigation Satellite System (GNSS) software receiver. Even if the topic of phase tracking has been widely studied, we found it useful to provide a short walkthrough for the design of a PLL in a real software receiver, avoiding to introduce the common theoretical phase-based model and aiming to the practical implementation of a system that deals with frequencies. Nonetheless, our analysis and design will grow away from the canonical approach, in the way that we will not resort to analog filter theory. The result is a PLL which is more reactive than the ones usually found in literature and that implements a si…
The Joint SLR (Optical Range) and Radar-VLBI Satellite Observations using VIRAC Radio Telescope RT32, RT16 and SLR Station Riga
2020
Abstract Joint VLBI and SLR satellite tracking is a novel tracking approach to explore potential applications and to work out common procedures to coordinate observations between astronomical observatories in Latvia. Global Navigation Satellite System (GNSS) satellites equipped with laser retroreflectors have been chosen as test targets because they are accessible by both measuring techniques – satellite laser ranging (SLR) and Very Long Base Interferometry (VLBI). The first Joint SLR and VLBI observations of selected GNSS satellites using three of Latvian large-scale astronomical utilities – VIRAC radio telescopes RT32 and RT16 (Ventspils International Radio Astronomy Centre of Ventspils U…
Race course profiling of the cross country ski using kinematic GNSS
2018
DFHRS-based computation of quasi-geoid of Latvia
2013
In geodesy, civil engineering and related fields high accuracy coordinate determination is needed, for that reason GNSS technologies plays important role. Transformation from GNSS derived ellipsoidal heights to orthometric or normal heights requires a high accuracy geoid or quasi-geoid model, respectively the accuracy of the currently used Latvian gravimetric quasi-geoid model LV'98 is 6–8 cm. The objective of this work was to calculate an improved quasi-geoid (QGeoid) for Latvia. The computation was performed by applying the DFHRS software. This paper discusses obtained geoid height reference surface, its comparisons to other geoid models, fitting point statistics and quality control based…
RFI: il caso studio della stazione GNSS dell’Università di Palermo
2009
La sperimentazione descritta in questo lavoro riguarda la prima parte di una ricerca, tuttora in corso, che vede coinvolti l’Agenzia Regionale Protezione Ambiente Sicilia (ARPA) e il Dipartimento di Rappresentazione dell’Università di Palermo (DIRAP), avente come tema le problematiche relative alle interferenze da radio frequenza registrate dalla stazione permanente GNSS dell’Università di Palermo. La stazione è stata materializzata nel 2006 e dal 2007 fa parte della rete di stazioni permanenti GNSS-NRTK gestita dal DIRAP, per attività di studio di ricerca. In particolare, in questo lavoro sono illustrati i test che sono stati condotti e i risultati in termini di interferenza elettomagnetic…
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
EDITORIAL FOR SPECIAL ISSUE: “GEOMATICS APPLICATION FOR GEOGRAPHY (GAG)” in GEOGRAPHIA TECHNICA
2021
Geomatics or Geography, that is the question! This is how the authors' idea of merging Geomatics and Geography in this special issue begins, paraphrasing a Shakespearean citation. The common principle that unites these two scientific disciplines, which attempt to describe the territory in the most straightforward way possible. On the other hand, Geomatics and Geography derived from “gèo- “[greek γεω-], as first element of composed words in learned and scientific terminology, meaning “earth”, “globe”, “land surface”.