Establishing a Reference Network in Parts of Amhara Region, Ethiopia Geodetic GPS Equipment

Since a reform regarding land use became valid in 1975 in Ethiopia, the farmers got long term rights to land owned by the state. In the beginning of the 2000’s a land administration project, Sida - Amhara Rural Development Program, SARDP, was initiated in the Amhara region, with the aim to survey, map and register the land parcels on their holders. This reform resulted in unpredictable difficulties concerning land partitioning and border determination. The problems originated from the fact that the existing reference network, which is a basic condition for determination of location, lacks in availability, precision and number of points. The purpose of this project was to create a reliable, accurate reference system integrated with the existing local reference system, accessible for everyone without any charges. The new established reference network consisting of 12 points was created in east and west Gojam region, in an area with approximately 140 km in east-west direction and 160 km in north-south direction. This master thesis is a description of how this particular reference network was made. It was carried out during 10 weeks as a Minor Field Study in the fall of 2008, in parts of the Amhara region, Ethiopia. For data collection 3 hours long static GPS measurements were performed in four sessions with Leica 1200 receivers. An IGS station and a CORS station located in Addis Ababa and in the town of Jima respectively were used as reference stations in the data processing. To achieve higher accuracy ionospheric correction files and precise satellite orbit data were imported for the processing. The result of the project is presented in both geodetical and Cartesian coordinates, in the frames of IGS05 and ITRF05 in the measurement epoch as well as in the standard epoch of year 2000. The results will also be presented in the national system Adindan UTM37N, which were transformed from IGS05 using a given parameter set from the Ethiopian Mapping Authority, EMA