Quality statistics of the 3D BAG
The table below show the quality statistics that are computed for each update.
|Select a month:|
|Total number of buildings|
|Buildings with valid height|
|Buildings with invalid height|
|Buildings missing height information for the roof|
|Buildings missing height information for the ground|
Additional to the metrics above, it is good to have an estimate on how well does a building model approximate the geometry of its real-world counter part. Therefore we computed the root mean square error (RMSE) of the geometric difference between the point cloud and the 3D building model at each percentile for 470 buildings in two areas of Delft. The geometric difference is represented by the shortest absolute distances from all point in the point cloud to the building model. Only those points are used from the point cloud that contribute to the creation of the 3D model.
The diagram of the RMSE of geometric difference, grouped by the type of the roof. We can see that in the models at the height of 75th percentile are the “closest” to the real geometry of the building and in case of buildings with flat roofs the RMSE is as low as 25cm on average. But even in case of buildings with non-flat roofs the RMSE stays in the 50–100cm range for percentiles 75–99.