As we know, if I want to add new places or ways on the existing map, the zoom level of the base map will effect closely the accuracy of the added points. I am wondering if there is any reference to show me how to decide which is the proper zoom level for such kind of editing. thank you for your attention. asked 30 Dec '11, 10:19 enrizh |
The only reference is your own data source. Use a zoom level that correlates with its accuracy. If you know the exact coordinates, just use them as they are. If you only have approximated coordinates (the most common case, e.g., from a GPX track) which may vary a few meters from reality, then adapt your zoom level accordingly. You obviously don't have to use a zoom level that allows editing within a few centimeters then. It also depends on the type of data you want to edit. Landuse, for example, doesn't require an accuracy as high as single POIs or roads. Nevertheless you should try to edit as accurate as possible. But always remember that your data source (GPX track, imagery, ...) also has errors and is not 100% accurate. answered 30 Dec '11, 14:25 scai ♦ |