Starting my work on my Austria maps. Here is a lesson in precision vs accuracy. The Cyan line is from the Austrian government and it is an administrative boundary of a cadastral community. The magenta line is my trace of the same boundary as indicated via Open Street Map's Mapnik overlay. I also have a pic without my trace in magenta and those boundaries are indicated with a dash and dot type of grey line. Also included the satellite version for reference. The cyan line is very precise. It follows the boundaries exactly when looking at the Mapnik map. But it's shifted a fairly consistent amount. In this case to the east (right) and a little bit to the north (up). The Austrian government's boundaries are the only ones from a free database that don't have a copyright from GADM, the organization that has them. The rest do, but GADM allows non-commercial academic use. Lots of maps that used these administrative boundaries use these files from GADM, and a couple others, but never correct them. I could do the same, but I quickly figured out that all of them are off to a certain degree. GADM seems to be the closest and it's sometimes highly accurate. Why does that matter? Well in some ways it doesn't because of how the winegrowing areas are created. Lots of land is included that don't have vineyards so being off a few miles isn't a big deal. But, there are places where the vineyards are right along a boundary, and THAT IS important to me to get right. This is why I'm claiming my maps will the the most accurate AND precise for the winegrowing areas of the world. Most of the time I'm redrawing the lines. I've gotten better at efficiency, but it's still a long a tedious process. #maps #winemaps #map #winemap #wine #googleearthpro #googleearth #mapnik #openstreetmap #sommlife #questforthegreenpin https://www.instagram.com/p/Chyw191uZIx/?igshid=NGJjMDIxMWI=
