The problem is that the shape of the grid, as well as all the geographic features depends on the map projection. See: http://geology.isu.edu/geostac/Field_Exercise/topomaps/distortion.htm
To first order, you take a geographic object as a list of lines between lat-lon points, use the map projection to convert lat-lon to x-y and then plot the lines in x-y coordinates. The lat-lon grid is added using the same procedure so it is subject to the same distortions. > > Does anyone have a map of the Earth, showing a full hemisphere with > longitude lines spaced every ten degrees? > > I need the grid as a vector file to use with a Moon Map I am producing, so > it has to be exact. > > Very difficult to find details about what shape the lines are, or how to > generate them in a program like Illustrator! > > Any suggestions about this would be most welcome. Link shows the sort of > Moon Map I am generating, with longitude lines. > > Thanks! > > http://als.wikipedia.org/wiki/Datei:Moon_landing_map.jpg > > > > > > * David Widdowson, ASTROVISUALS, * > > * 6 Lind St, Strathmore, 3041, AUSTRALIA > > * Ph/fax: 61- (0)3 - 9379 5753 * > > EMAIL: mailto:m...@astrovisuals.com.au > > WEB: http://www.astrovisuals.com.au/ > --------------------------------------------------- > https://lists.uni-koeln.de/mailman/listinfo/sundial > > --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
