As the accuracy and utilization of GNSS Surveying increases, the need for World Geodetic System as a unified Geodetic Reference System also increases. Most of GIS (Geographic Information System) data have been converted into the World Geodetic System,...
As the accuracy and utilization of GNSS Surveying increases, the need for World Geodetic System as a unified Geodetic Reference System also increases. Most of GIS (Geographic Information System) data have been converted into the World Geodetic System, Cadastral data are still maintained based on the Local Geodetic System. In order that Continous Cadastral Maps is used with other GIS data, World Geodetic System transformation procedures on the Continous Cadastral Maps are required but there are no systematic procedures or guidelines about it.
This study tested transformation procedures based on using various Common Points such as a Cadastral Control Points, Urban Control Points, Aerial Surveying Control Points for Continuous Cadastral Maps in Asan City. In addition, location and area variations between original and converted data were analysed. According to the results, the location was moved in NNE direction : approximately 306 meter toward X direction and approximately 71 meter toward Y direction. And there was approximately 0.0013~0.0019% difference in area variation with comparing to the original data.
Also, the accuracy was analyzed by overlapping the converted Continuous Cadastral Maps with the digital maps. In the results of accuracy analysis, Continuous Cadastral Maps converted by a Aerial Surveying Control Points showed the greatest locational accuracy with only 0.3cm distance error. The maps converted by a Urban Control Points were ranked next with 2.9cm distance error. And the maps converted by a Cadastral Control Points was most inaccurate with 35.36cm distance error. With considering that the error tolerance of boundary points in 'Cadastral Surveying Administraion Regulations' is within 15cm, Aerial Surveying Control Points and Urban Control Points can be used as a Common Points while Cadastral Control Points cannot.
This study demonstrated that Aerial Surveying Control Points or Urban Control Points should be used as a Common Points for the accurate World Geodetic System Transformation of the Continuous Cadastral Maps and it also suggested an efficient procedure for the World Geodetic System Transformation of Local Government Continuous Cadastral Maps.