Re: Kmz map misaligned

Posted by MichaelRaz on
URL: http://maprun.308.s1.nabble.com/Kmz-map-misaligned-tp1912p1918.html

I've been doing this (trying to georeference images maps) for many years for use with RouteGadget and I can say that some maps, especially older ones not developed with LIDAR, are often so skewed, stretched or just inaccurate.  This often has no impact on normal orienteering but make georeferencing a big challenge and not something that can be handled automatically with even 3 or 4 points.  

One suggestion is to use GoogleEarth directly.  Add the map image as an image overlay and then you can adjust it in all different ways and try to get it as close as you can to match than save as a KMZ by stretching, rotating, skewing over and over again.  I'll promise you that this is an art more than a science!  

It may also give you an idea if the issue is with the image or the application.

The other thing to consider with respect to MapRun, depending on your goal, the KMZ does not really need to be that accurate as the controls KML location are what matters and, especially if you are actually using paper maps to do the orienteering, it may not be that important if the KMZ is a bit off.  This goes along with the principal that mappers may actually adjust things slightly on the map to map them clearer - KML control geo-location is what counts.

Although I'm basing this on the assumption that there are no issues with the application, it all still applies if Peter finds an issue - just not be applicable in this case.