* Paul Norman <penor...@mac.com> [160412 17:27]: > On 4/12/2016 2:40 AM, Christoph Hormann wrote: >> On Tuesday 12 April 2016, Martijn van Exel wrote: >>>> I was mapping some rural area in the U.S. and noticed, not for the >>>> first time, an aerodrome node in the middle of a field where there is >>>> obviously no airport or airfield.
>> I am not sure here. For small airfields the aeroway=aerodrome feature >> is a fairly abstract thing essentially indicating only that this is a >> place where aircrafts start or land. This is not generally something >> that can be reliably determined from imagery. > You can't reliably find small airfields from imagery, but I've found it > possible to verify a lack of airfields from it. I pass though > agricultural areas, and the airfields that are still active all appear > somehow on imagery, even if it's just an area where the ground cover is > different. On the other hand, some of the aeroway=aerodrome we have data > for include points in fields of corn, residential areas, and stands of > trees. One added problem here is that the coordinates of imported data are not always that good. As an example check Zortman Airport http://www.openstreetmap.org/node/1042048666 The original import was more than half a mile off. Wolfgang _______________________________________________ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us