Coordinate transformation of cadastral maps using different adjustment methods

Abstract

In Turkey, cadastral work began during the Ottoman Empire. There are several kinds of cadastral maps created by different production methods, coordinate system, base type, measurement, and calculation methods. These maps must be transformed into the Turkish national coordinate systems. Although there are many coordinate transformation methods, the affine transformation method is most commonly used in map transformation. The affine transformation solution consists of the adjustment of the obtained unique and best suitable parameters estimation. Although the least square (LS) adjustment method is in widespread use, there are some disadvantages in the determination of erroneous measurements. The least absolute value (LAV) determines the erroneous measurements and their effects on the other measurements results. In recent years, the total least square (TLS) method has been frequently used for estimation parameters. This study examines the transformation of non-digital cadastral maps in Turkey. After the evaluation of the current situation of cadastral maps, the affine transformation method is explained using adjustment methods. Finally, the success of affine transformation combined with the LS, LAV, and TLS methods is demonstrated by a numerical application. Thus, the most suitable adjustment method is obtained according to the results of the application.