  The paper concerns the use of satellites of the Galileo constellation for
relativistic positioning and for measurements of the gravito-magnetic effects
induced by the angular momentum both of the Earth and of the dark halo of the
Milky Way. The experimental approach is based on the generalized Sagnac effect,
induced both by the rotation of the device and the fact that the observer is
located within the gravitational field of a spinning mass. Among the possible
sources there is also the angular momentum of the dark halo of the Milky Way.
Time modulation of the expected signal would facilitate its disentanglement
from the other contributions. The modulation could be obtained using satellites
located on different orbital planes.
