Airborne remote sensing for urban drainage

Land cover information suitable for urban drainage modelling is acquired by airborne remote sensing. The scanner used is a line scanner that scans continuously while the aircraft flies forward recording 11 bands of the electromagnetic spectrum. This is classified by first segmenting the image into approximately homogeneous polygons using a Marr–Hidreth edge detector. These polygons are then classified into roofs, paved areas and permeable land. Rigorous accuracy tests are applied to the classified imagery, which shows that this method gives better results than any of those currently used. Dawn thermal imagery was not used in this study.