Introductory Chapter: The Philosophy Behind the Accuracy Assessment of GNSS Methods

Satellite geodesy was developed to overcome the tasks which cannot be accomplished using traditional geodetic techniques, for instance, to measure the motion of continents more precisely, to eliminate the difficulty in line of site problems, to gain performance in all weather conditions, and to be able to monitor global deformations of the earth leading to the contribution in the emerge of a terrestrial reference frame (TRF) which is compatible with the geodynamic events of the earth.