@article {59, title = {Copertura della Costellazione QZSS (Quasi-Zenith Satellite System)}, journal = {ATTI DELL{\textquoteright}ISTITUTO ITALIANO DI NAVIGAZIONE}, volume = {187}, year = {2008}, chapter = {91}, abstract = {
The objective of this work is the study of the QZSS constellation coverage; QZSS is a satellite\ 
system planned by Japan space agency as a GPS augmentation, to improve performances above all\ 
in zones with high urbanization, characterized by the so-called {\textquotedblleft}urban canyon{\textquotedblright}. In these zones a lot\ 
of GPS signals are blocked by buildings and they can{\textquoteright}t be used by GPS receivers, so there are often\ 
bad satellite observation geometries with no precise or even impossible positioning. QZSS\ 
satellites, because their orbital parameters, stay for a lot of hours in a day above the served areas\ 
with great elevation angles and so they give a good solution to the blocking problem in the towns.\ 
In this analysis to verify the improving of GPS coverage on Japan territory with QZSS satellites, it{\textquoteright}s
been made a computer simulation, which confirm the QZSS usefulness.\ 
Such coverage improvement could be obtained in every place of earth, because of quasi-symmetry\ 
of GPS constellation, changing the reference meridian of QZSS ground tracks; so it{\textquoteright}s been made the\ 
same simulation for Italy too, with more details obtained using a 3D model of an area of the centre\ 
of Naples.\ 
}, issn = {1120-6977}, author = {ANGRISANO, A and PACIFICO, A and VULTAGGIO, M} }