|
Land Revision is a daily work in land administration office, which can mainly be divided into digital Surveying and graphic Surveying. It would be easier to restore the location of boundary coordinates when using digital Surveying on the control point did not lost. For graphic Surveying we can only do that base on reliable cadastral boundary coordinates points and lines. Recently, after digitalized the graphic cadastral maps all over the country, it makes it possible to do digital Surveying for land revision of the cadastral map. This research utilized the e-GPS base stations network system which was set up by land administration bureau of Tainan county government in year 2007. Control points are measured in testing area, highly durable supplementary control points are settled on buildings front wall by the electronic theodolite. The highly durable supplementary control points which use free-station method to measure a reliable boundary points coordinates, needs both repeatedly observation adjustment and coordinates transformation. This research explores feasibility study to perform for digital land revision work. Experimental results showed that the accuracy of highly durable supplementary control points can be controlled within 2 cm after coordinate transformation. Using highly durable supplementary control points in the digital land revision work, all the results can satisfy the cadastral survey regulations of boundary points (Maximum of 6 cm in coordinates).Digitalized graphic maps of land revision can also be limited within 24cm. some portion parts can even achieve the accuracy of digital land revision relations. Moreover, after the coordinates got transferred, it could not only be used in TWD97 coordinates system, but also can avoid the problems of reconstructing the control points when they got losed, All correct results can be stored in cadastral database which makes that the results of land revision could be reused, and effectively shorten the Surveying time by using that data base. Even processed by different Surveying officers, we shall not worry about that the measuring results are not consistent for a land parcel in different measurement process.
|