User perspective on geospatial data quality. Case study of the Polish Topographic Database

The aim of the paper is to analyze the quality of geospatial data from the user perspective, which is application oriented and differs from that of the data provider due to the performance of specific tasks. Generally the overall description of data quality, reported in metadata, comprises characteristics of the data set parameters such as completeness, accuracy, and consistency of data. However, this information is very important it shows data conformance with its specification but for most of the users is not sufficient. The authors present innovative method for assessment data quality on the level of object classes focusing on spatial location of missing objects and their attributes as well as the information whether some attributes assume null reason values. The results are obtained automatically, on the basis of elaborated algorithm and reported in the form of choropleth map which should be displayed as one of the layer in a geoportal. The method was tested on land cover dataset, stored in the Database of Topographic Objects for Olsztyn.