The WMM predicts the difference between true north and magnetic north around the world for the period 2005-2010. I believe that this is the same model as used in most hand held GPS receivers.
I have ported the USGS WMM C code at http://www.ngdc.noaa.gov/geomag/WMM/wmm_cdownload.shtml to javascript. You will find my javascript at http://wheresthepath.googlepages.com/WorldMagneticModel.js This code appears to give the same results as the BGS online calculator at http://www.geomag.bgs.ac.uk/gifs/wmm_calc.html. Feel free to use for any purpose. Bill Chadwick --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google Maps API" group. To post to this group, send email to Google-Maps-API@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/Google-Maps-API?hl=en -~----------~----~----~----~------~----~------~--~---
