  Uncertainties in the satellite world lines lead to dominant positioning
errors. In the present work, using the approach presented in \cite{neu14}, a
new analysis of these errors is developed inside a great region surrounding
Earth. This analysis is performed in the framework of the so-called
Relativistic Positioning Systems (RPS). Schwarzschild metric is used to
describe the satellite orbits corresponding to the Galileo Satellites
Constellation. Those orbits are circular with the Earth as their centre. They
are defined as the nominal orbits. The satellite orbits are not circular due to
the perturbations they have and to achieve a more realistic description such
perturbations need to be taken into account. In \cite{neu14} perturbations of
the nominal orbits were statistically simulated. Using the formula from
\cite{col10a} a user location is determined with the four satellites proper
times that the user receives and with the satellite world lines. This formula
can be used with any satellite description, although photons need to travel in
a Minkowskian space-time. For our purposes, the computation of the photon
geodesics in Minkowski space-time is sufficient as demonstrated in
\cite{neu16}. The difference of the user position determined with the nominal
and the perturbed satellite orbits is computed. This difference is defined as
the U-error. Now we compute the perturbed orbits of the satellites considering
a metric that takes into account the gravitational effects of the Earth, the
Moon and the Sun and also the Earth oblateness...
