Manhole cover detection using a geometrical filter on very high resolution aerial and satellite images

One of the direct consequences of urban growth is the multiplication of buried utility networks. It is difficult to obtain complete and accurate maps of these networks because they have often been produced by different parties at different times. This work aims at putting forward a methodology to detect manhole covers on high resolution images, in order to reconstruct an urban drainage network. A circular detection filter is applied to high resolution orthophotos and Pléiade images to pinpoint mahole covers. The primary results are encouraging as 42% of manhole covers are detected by this method. Further work is carried out to improve the method and extend it to rectangular grates, that are not detected by the circular filter.