User:Amgine

From Wiki.GIS.com

Hi, I hope that this helps...the Winkel Trippel projection is only used for world maps. As it is not conformal, i.e. the map scale is different for latitude and longitude. I would plot coordinates by using linear interpolation along both lines of latitude and longitude. So, measure the distance between two latitude lines, say 10 degrees apart, perhaps this distance is one inch. So each degree of longitude corresponds to one tenth of an inch. Do the same for two lines of longitude, and you'll see the scales are different. Once these scales are determined, you can use them to measure the coordinates of any point from the reference lines. For this purpose I like to use 10-point dividers. They're pricey, but if you do this kind of work a lot (as I once did creating groundwater gradient maps) they'll save a lot of time. But, an ordinary ruler works too! http://www.amazon.com/Weems-Plath-Marine-Navigation-Divider/dp/B000IMYY1Q