Abstract
A spatial grid data set can be described as a spatial data set which contain categorical or continuous values at a gridded format. Accuracy of the data is shown by using measures such as overall, user's, and producer's accuracy when categorical values stored, and Root Mean Squared Error (rmse) and Pearson’s correlation coefficient when continous values stored. However as such measures are global and static indicators, it is difficult to demonstrate accuracy spatially. Therefore, the aim of this study is to extend accuracy measures of spatial grid data spatially under the assumption of Toblar’s first law. Recently many open data can be accessible, however those accuracy have not been paid attention to. As spatial variations of accuracy in the spatial grid data can be visualized, data users and producers are able to understand the accuracy of the data deeply.
