Special Topics in GIS Lab 9

This week in the lab we learned about accuracy statistics when using Digital Elevation Models (DEMs). In order to accomplish the analysis process you need a DEM to analyse and test elevation points that cover the DEM extent. This analysis is only for the vertical elevation accuracy. We focused on horizontal accuracy in the first part of the semester. For the vertical accuracy statistics we plotted the test points against the DEM then derived the elevation values of the DEM pixels at the test point locations. By comparing the two values we were able to calculate RMSE including the 95th and 68th percentile statistics. The image below shows the result of the vertical accuracy testing. The letters a through e are the different types of land cover represented in the test  points. These were provided as comparison factors for the accuracy statistics. The overall accuracy is listed at the end under All.