A method for building legal digital cadastre without using cadastral measurements field book data : is it accurate enough?
Jarroush, Jad & Dima Brickman
Usually, in countries where the cadastre system is based on the Torrens method, the cadastral block map is accompanied by field books and field sheets. The field book is the entity that documents the measurements of the boundaries of cadastral parcels during the land settlement process, and describes their linkage to the national cadastral control grid. Correspondingly, the field sheet plan is compatible with the same block map which documents all the fronts' measurements between the boundary points and other geometric constrains such as distances between boundary points and national control points, parallel boundary lines, etcc Since most of the cadastral blocks were established in the far past, their measurements are based on the chain method. Thus, according to the instructions of many surveyor regulations, in order to reinstate the position of the boundary points in the field today, the surveyor should compute the coordinates of the cadastral boundary points in the up-to-date national control grid and mark them physically with wedges. This process involves analyzing and computing the documented measurements in the field book which is considered to be a complex and expensive process since it consumes time and effort. In some cases, field books have even got lost. In these cases, the instructions of cadastral regulations recommend surveyors to digitize the graphical block map and try to manually adjust the documented measurements in the field sheet with the graphical digitized point coordinates.
Event: FIG Working Week 2012 : Territory, environment, and cultural heritage
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