Error detection

Types of errors

• Digitizing errors– overshooting– undershooting– polygons do not close– missing data

An example of horrible digitizing!!!

Contour lines never cross!!

“dangling” node

overshooting

River digitizedin the wrong direction

3500m

3900 m

Digitizing rivers in the wrong direction creates “canyon” -like features instead of river valleys

Types of errors

• Location errors (x,y coordinates)• Edge matching (“seamless”)