Assessment of relative and absolute accuracy Descriptive statistics of elevation values of CPs and of the three DEMs are reported in Table 2.
The CPs are equally distributed among plains, hills and moderate relief at medium elevation and the TINITALY is a little closer to the CP than the other DEMs. A synthesis of the results of the accuracy assessment is given in Table 3 which shows the values of min and max and mean error, root mean square error, standard deviation, standard error and confidence interval (CI = 95%). As shown in the Table 3, the RMSE of DEM95 elevation is about twice to that of TINITALY, much lower than the one of ASTER GDEM.