The paper deals with a high-precision geodetic network densification by means of GNSS based geodetic solutions, in the view of the fact that the initial data are represented in different reference frames. Indeed, reference station positions are represented in GSK-2011 terrestrial reference frame whereas GNSS satellites` ephemeris are represented in other reference frames, such as ITRFs, WGS84, etc. Two methods are considered in the paper to provide GNSS observations with a correct processing procedure: in the first method all the initial data are transformed into the satellite ephemerid reference frame, and in the second one – into GSK-2011 terrestrial reference frame. To supply these translations, 7-parameter Helmert time-dependent transformations for both methods were developed. After all, GNSS observations over the period of 2010–2016 of the permanent stations of Moscow region were processed with the second method and some processing results were displayed in the paper to show the efficiency of the developed techniques.