Change Detection for Updating Medium Scale Maps Using Laser Altimetry

To increase the update rates of topographical databases, research is performed to automatically detect changes using airborne laser scanning data. After the determination of the bare-Earth points, the remaining points have been classified as either points on buildings or points on vegetation. Additional usage was made of registered colour imagery taken during the laser scanning survey. The results show that buildings can be detected reliably using laser altimetry data sets. However, they also show that mapping rules (which buildings should be in the map and which can be neglected) need to be implemented accurately. Otherwise, the change detection procedure would signal a need for map updating for buildings that are not to be mapped.