Impact on Bangkok metropolitan areas through the first-class mapping method by the real time kinematic satellite network (RTK GNSS Network)

Abstract

This research aims to find Combine Scale Factors and design a tool to find shrinkage area or stretch area on QGIS software. Research is conducted on Bangkok metropolitan areas. Using data from the Thailand surface level survey project to create a water dam of the Royal Thai Survey Department. The location data will show the coordinates of the plane (False Northing, False Easting), elevation above the ellipsoid (h) and height above mean sea level (MSL). The Combine Scale Factor is calculated using Geoid Model as the basis of research concept. In order to reduce the flat distance on the terrain (Ground Distance) to the flat distance on the grid coordinates UTM (Grid Distance). When calculating, the Combine Scale Factor values for all locations in Bangkok metropolitan areas. Design a tool to find shrinkage area or stretch area. The positional datasets are approximately 4 kilometers apart, requiring a range estimation to improve the accuracy. Estimated using the Inverse Distance Weighted (IDW) method, a grid pattern of approximately 1*1 km of the research area. Results of the research 1). Get the Combine Scale Factor value in Bangkok metropolitan areas. To be used in conjunction with the Total Station theodolite in the construction of a large real estate project. 2). Get a tool to find shrinkage area or stretch area on QGIS software. When drawing plots of land on the map. The program will tell the area on the UTM coordinates and the area on the terrain surface. Make an area comparison it will know that the area on the UTM grid is shrinking (-) or the area stretching (+) in Bangkok metropolitan areas.