ITRF (International Terrestrial Reference Frame) determines the origin, alignment of the system 's fundamental planes or axes, scale, physical constants, and models such as the size, shape, and alignment of the reference ellipsoid. The ITRF is regularly updated to take into account the Earth's dynamics and is now sufficiently re-fined to ensure that the change between successive ITRF versions is in the order of 1-2 cm. The Egyptian Survey Authority (ESA) established the Egyptian's HARN (High

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... uracy Reference Network) and linked it to the international frame (ITRF1994 epoch1996) as a static frame. As this datum is static, coordinates of stations do not change with time, ignoring both the tectonic motion and the different definitions for all following ITRF realizations. With the continuous increasing progress of using the IGS and CORS stations as well as the merging of the concept of tectonic plate motion, and the Precise Point Positioning technique has a well know precise technique, there were offset in the current coordinates of the HARN network about 40 cm, so a set of simple transformation parameters (T x , T y , T z ) calculated. In the current study, Plate Motion Models (PPM) and Egyptian Deformation Model (EGY-DM) were investigated based on ITRF2008 epoch2015.4 to choose the best model in calculating the computed parameters. The evaluation process of the computed transformation parameters on chosen points of HARN & NACN (Notational Agricultural Cadastral network) demonstrates that the estimated transformation parameters by EGY-DM give the lowest horizontal and vertical differences 16 mm and 17mm, respectively, and with standard deviation does not exceed 2 cm, except one station due to deficiency of observation time.