On Wednesday 30 December 2015, Jotam wrote: > > I wanted to reply to Christoph's objection about schools being hard > to identify on aerial imagery. In fact, it is pretty easy to identify > Ugandan schools on satellite pictures as almost all school grounds > are set up to a very particular pattern and shape. This may sound > improbable to Western ears. But Ugandans like to simply copy a once > tried and tested concept. That's why almost all school compounds look > alike.
You are right, this does sound unlikely w.r.t. a volume of 24k schools all over Uganda - not from a narrow minded western viewpoint but based on basic understanding of schooling practice all over the world and observation of currently mapped schools in Uganda: http://mc.bbbike.org/mc/?lon=32.493016&lat=0.845208&zoom=17&num=3&mt0=mapbox-satellite&mt1=mapnik&mt2=google-satellite http://mc.bbbike.org/mc/?lon=32.477664&lat=0.849601&zoom=17&num=3&mt0=mapbox-satellite&mt1=mapnik&mt2=google-satellite http://mc.bbbike.org/mc/?lon=32.469376&lat=0.831407&zoom=17&num=3&mt0=mapbox-satellite&mt1=mapnik&mt2=google-satellite The fact that you can recognize some schools in Uganda by common architectural elements (which by the way also applies to other parts of the world) does not change anything here - this might be helpful for remote mapping to identify some schools, it is not of any use for verifying separately acquired data. Note i am not saying the data is bad and should not be imported but since it is not possible to verify it based on available imagery it would be necessary to see and demonstrate if the data is reliable before making plans for an import. Currently the import documentation does not even contain the basic information that can be assessed without on-the-ground knowledge, like how many schools are currently mapped in OSM within the area of the import, how many are both in OSM and in the new data and how many are only in one of them and not in the other. IMO this is a basic requirement for a useful import discussion. On-the-ground assessment of the data in a few sample areas would be good to have in addition of course. -- Christoph Hormann http://www.imagico.de/ _______________________________________________ Imports mailing list [email protected] https://lists.openstreetmap.org/listinfo/imports
