Evaluating the Egyptian HARN Network by GNSS Precise Point Positioning “PPP” [ READ ]
Mostafa Rabah, Mahmood Elmewafey, Magda H. Farahan, Ahmed Awad and Ali. Jaafar
One of the fundamental goals of geodesy is to precisely define positions of points on the surface of the Earth, so it is necessary to establish a well-defined geodetic datum for geodetic measurements and positioning computations. Recently, a set of the coordinates established by using GPS and referred to an international terrestrial reference frame could be used as a three-dimensional geocentric reference system for a country. Based on this modern concept, in 1992, the Egypt Survey Authority (ESA) established two networks. The first net is called High Accuracy Reference Network (HARN) and consisted of 30 stations, 200 km spacing. The second network was established to cover the cultivated areas (Nile Valley and Delta) so it is called the National Agricultural Cadastral Network (NACN) with spacing 30 to 40 km. To transfer the International Terrestrial Reference Frame to the HARN, the HARN was connected with four IGS stations. The processing results were 1:10,000,000 (Order A) for HARN and 1:1,000,000 (Order B) for NACN relative network accuracy standard between stations defined in ITRF1994 Epoch 1996.
Mostafa Rabah, Mahmood Elmewafey, Magda H. Farahan, Ahmed Awad and Ali. Jaafar
One of the fundamental goals of geodesy is to precisely define positions of points on the surface of the Earth, so it is necessary to establish a well-defined geodetic datum for geodetic measurements and positioning computations. Recently, a set of the coordinates established by using GPS and referred to an international terrestrial reference frame could be used as a three-dimensional geocentric reference system for a country. Based on this modern concept, in 1992, the Egypt Survey Authority (ESA) established two networks. The first net is called High Accuracy Reference Network (HARN) and consisted of 30 stations, 200 km spacing. The second network was established to cover the cultivated areas (Nile Valley and Delta) so it is called the National Agricultural Cadastral Network (NACN) with spacing 30 to 40 km. To transfer the International Terrestrial Reference Frame to the HARN, the HARN was connected with four IGS stations. The processing results were 1:10,000,000 (Order A) for HARN and 1:1,000,000 (Order B) for NACN relative network accuracy standard between stations defined in ITRF1994 Epoch 1996.
