Summary:

Nowadays, there are many various algorithms used to transform spatial data between coordinate systems 1965 and 2000. Ideal algorithm should be: con-tinuous, accurate, fast, easy to use even not by professionals. It should model dis-tortion of the coordinate system on both: high and low classes networks. Some of widely used algorithms guarantee continuous results over whole zone of 1965 but do not include local distortions of lower classes networks. The most popular ex-ample is "empirical" transformation algorithm, which fits to first and second class networks with few centimeter accuracy. On the other hand, surveyors often use lo-cally fitted transformation which allows to achieve high accuracy but causes an inconsistency between two independently transformed areas. The possible solution is the grid of shifts between coordinate systems. This algorithm is, already used in many countries (for example: USA, Canada, France) but has not been applied in Poland yet. In this article some methods of creation such grid are discussed and various tests on empirical data are described. Results show that it is desirable to create such grid on whole area of Poland.