Base maps can be re-projected if needed. A rectangular projection suitable for larger areas is Lambert Equal Area (which, as the name suggests, allows acceptable area calculations). An example is EPSG 3035 that fits for whole Europe without too much of distortions at the edges. You can define a LAEA projection for the map with parameters to suit your needs.
armin On 29/05/2012 20:47, Chris Jackson wrote: > Hi Armin > > I use another webgis system that splits out the map display from the > geometry side - hence the thought, and have some basemaps that prefer > web mercator. Trouble is have a new project that has an initial extent > that is really a bit big for a local grid projection, so just feeling > out the options. > > Roll on v5! > > Cheers > Chris > > > > On 29 May 2012 18:24, Armin Burger <armin.bur...@gmail.com > <mailto:armin.bur...@gmail.com>> wrote: > > On 29/05/2012 09:30, Chris Jackson wrote: > > Hi all, > > > > Is it possible to have PMapper displaying the map in say Web > Mercator and > > then measuring distances and areas from a local grid system? > > > > in p.mapper 4.x not without some rewriting of functions in pm.draw.js > (and usage of proj4js). In p.mapper 5 it should be possible with the map > property "displayProjection" (given that OpenLayers does the > measurements this way if you set the display projection to a local grid > system). > > On the other hand, why would you want to use spherical mercator for the > map in p.mapper 4 if you do not need to show maps at global scales > (which I don't know if you want...) ? > > armin > > > ------------------------------------------------------------------------------ > Live Security Virtual Conference > Exclusive live event will cover all the ways today's security and > threat landscape has changed and how IT managers can respond. > Discussions > will include endpoint security, mobile security and the latest in > malware > threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ > _______________________________________________ > pmapper-users mailing list > pmapper-users@lists.sourceforge.net > <mailto:pmapper-users@lists.sourceforge.net> > https://lists.sourceforge.net/lists/listinfo/pmapper-users > > ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ pmapper-users mailing list pmapper-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/pmapper-users
