Enhancement of Google Earth Positional Accuracy

Abstract

Google Earth is one of many online mapping applications that offer users interactive mapping capabilities. It is often being used by academic users as a source for reference or base maps. It provides an open source, easy access and cost free image data that support map interest community. This contemporary high resolution archive of the Earth's landmass represents a significant, rapidly expanding and largely unexploited resource for scientific inquiry. Therefore, many individuals and researchers still use Google Earth as a reliable and accurate data source for mapping applications. This issue raises questions about the expected positional accuracy of Google Earth, which is the main interest of the current research. In this context, the positional accuracy assessment was not carried out directly on the Google Earth imagery, but on a selected scene for a certain study area that resulted in a corresponding non georeferenced image. Then, it is georeferenced with the aid of some control points in order to be compared with a base ground surveying map, on which the accuracy assessment will depend on the coordinates' discrepancies of some selected well-defined check points. The results show a significant improvement on the horizontal accuracy, related to all previous similar researches, that finally yields to sub-meters accuracy in the horizontal positions. However, this finding can be valid in the place of study, besides coordinates extracted from Google Earth imagery should be used with care caution.