UML-GML transformation ambiguity

Abstract

Passing the “Spatial Information Infrastructure Law” in Poland, that is a transposition of the INSPIRE Directive, involved the necessity of many secondary acts and corresponding changes in other Laws, among others the “Geodetic and Cartographic Law”. Decision was made to replace the existing instructions and guidelines by regulations of the Council of Ministers or relevant minister that, on the one hand, become annexes to the “Geodetic and Cartographic Law” and, on the other hand, implement the recommendations of the INSPIRE Directive.
An integral part of these regulations elaborated in the Head Office of Geodesy and Cartography in Poland are the UML and GML application schemas that define information structures of databases, corresponding to each regulation. Although these schemas were worked out according to the ISO 19100 series of International Standards in the Geographic Information (Geoinformation/Geomatics) domain, many technical problems connected with UML-GML transformation were identified during their preparation.
In this paper, on examples of UML and GML application schemas prepared in the Head Office of Geodesy and Cartography in Poland within the INSPIRE Directive implementation works, some ambiguities concerning UML to GML transformation were discussed as well as some errors and anomalies connected with this issues. Questions how to resolve this ambiguity and how to ensure single way in changing UML application schema into corresponding GML application schema were also considered.