The overall range of the error distribution for ASTER elevation is wider than those for DEM95 and TINITALY and the most frequent errors are positives. The characteristics of the error distributions of DEM95 and TINITALY resemble each other, and the frequencies of positive errors are greater than those of the negative errors for both DEM95 and TINITALY, which indicates a small positive bias for both models.
Error correlation analysis Considering that the error possibly correlates with the elevation, the values of the CPs have been taken as a control variable, and carry out partial correlations between the errors of the DEMs. In the comparison DEM95 - TINITALY the error correlation is r = 0.43 (p