Geographical Simultaneity: A New Index to Validate Results Obtained From Digital Image Processing of Thematic Maps

Abstract

New technologies have enabled the dissemination of maps. Maps are commonly produced either by sophisticated image processing techniques or by more conventional methods. Therefore, defining the limits of the use of maps by measuring their associated errors is essential. There are several sources of such errors, which can be related to temporal, positional and interpretation aspects, among others. Regardless of the source, maps must be validated. The main procedures to validate maps are the Kappa (KI) and the Tau () indices. These indices often present inconsistencies due to the marginal variations. This study presents a new index, the Geographical Simultaneity (GS), which corrects these inconsistencies. Comparison of GS, KI and  results involving both hypothetical data and data available in the literature demonstrated the effectiveness of the use of GS.