Positional Accuracy Evaluation of Google Earth in Addis Ababa, Ethiopia

Abstract From the time when it was first launched in 2005, satellite data generated from Google Earth are freely available online. Hence, without being conducting concrete studies about the accuracy of satellite data from Google Earth, Google Earth are chiefly used for different field of studies in different sectors for different purposes in Ethiopia. In this regard, it was planned to conduct this study by establishing the main objective to evaluate the positional accuracy of Google Earth. Hence, in order to address the aforementioned objective, a brief methodology for collecting and analyzing data was performed. The positional accuracy of Google Earth for both horizontal and vertical cases was evaluated. The acquired horizontal RMSE of Google Earth was found fit to produce a class-1 map of having 1:20000 scale as recommended by ASPRS-1990. Unlike for horizontal case, the computed RMSE for vertical positional accuracy of Google Earth was not found fit for preparing class-1 map. However, making correlations between field survey and GE can provide 95% fitness, and also, subtracting the acquired RMSE for the vertical case from the original Google Earth elevation data can provide a 90% fitness for preparing class-1 map as well.