A visibility test on SPOT5 images

Two visibility tests have been made on a fusion of panchromatic and multi-spectral SPOT5 images. The tests differ in the type of regions (sub-urban versus rural) and in the panchromatic image resolution (5m versus 3m). Two independent photo-interpretors had to extract the road network and the built-up area on part of a georeferenced image. The resulting shapes were compared with the actual database. Two methods were used for this comparison. It appears that the visibility is highly dependent on the experience of the photo-interpretor. The expert reaches a rate of approximately 85% of road detection in all regions, more than 85% of the built-up area in the sub-urban region, and approximately 65% in the rural one.