Not long ago someone asked how GPS units handle magnetic variation/declination. In my reply, I speculated that Garmin GPS units used a look-up table. Garmin recently confirmed this by releasing firmware upgrades for the Garmin GPS 12, GPS 12XL, and GPS 48 that in part update their magnetic variation look-up tables. (Magnetic variation changes slowly over time; in parts of the Boundary Waters in northeastern Minnesota, it is approaching zero.) For the 12XL and 48, the new firmware version is 4.58. (4.x versions of the 12XL only). The new versions can be downloaded from http://www.garmin.com/support/download.html. BTW, if you have a GPS unit and haven't learned the UTM grid system yet, I recommend that you do so. Canadian topo maps have the UTM grid printed on them, and during a recent trip in the NE corner of Lake Superior, where the shore is fairly straight and there are not many landmarks to triangulate from, it was very easy to see where I was on the map within 50-100 meters just by reading the GPS and interpolating between the grid lines. Chuck Holst *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced/forwarded outside PaddleWise without author's permission Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
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