Netolygiųjų atsitiktinių deformacijų sumažinimas transformuojant fragmentiškai

Abstract

Many specialists in geodesy and cartography face the necessity of transformation from one coordinate system to another one. An important group of transformation work is the transformation in order to abolish different uneven distortions of cartographic material. This problem is quite common in digital cartography and extremely important in the initial stage of cartographic databases, when a lot of old paper map sheets are used with aneven deformation in many cases. It is extremely important to abolish uneven deformations in establishment of geo databases of engineering network: in every cycle of addition all information to map sheets at the moment of copying buildings different random errors of object location took place. Taking into consideration the level of modem technologies we should use only computerised transformation methods. In reality transformation methods which may be applied by GIS/CAD commercial software are used. These are, as a rule, Helmert, Affin and Projective transformation methods. Expensive commercial software give opportunity to use Nearest (Nearest Neighbor Assignment), Bilinear (Bilinear Interpolation), Cubic (Cubic Convolution) transformation methods. This short overview shows that the most popular commercial software does not provide possibilities to abolish uneven deformations. It indicates the necessity to replenish the existing popular GIS/CAD software with appropriate functionality mentioned above. The article describes an experiment. The main goal of it was to assess possibilities of fragmental method for abolishing uneven deformations. For implementating the experiment the research model was elaborated in ArcView Avenue programming language.