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Yesterday I was doing some initial planning for my 2021 Western fly fishing trip when I stumbled on a "problem" with converting formats for GPS coordinates.  While I don't know or even care about the various names of the several different types of GPS formats that exist, I've always assumed that when converting from one to another (there are numerous programs for this purpose - just Google it) the results of the conversion would result in a location that is reasonably close to the original location.  Unfortunately, my results yesterday for one particular location that I have been to before were 200 to 300 yards off.  For most purposes this magnitude is really not all that important.  However, I can see certain situations where this could result in "problems".

This is the example I was dealing with:

In Google Maps, the coordinates 43.456592, -109.547743 will result in a nice boondocking spot right on Torrey Lake which is located east southeast of Dubois, WY.  In order to get this coordinate into my new Garmin 890 (or any Garmin for that matter) I had to convert this decimal coordinate to the "old" degree, minutes, seconds format that Garmin uses - yes, I'm aware that Garmin can use several different GPS coordinate formats but the decimal format is not one of them.  So, using a converter I got N 43 degrees 27 minutes 23.731 seconds, W109 degrees 32 minutes 51.874 seconds.  When entering these coordinates into the Garmin, the result on the Garmin map is a location 200 to 300 yards further to the east northeast as compared to the Google map location.  This result is close enough for my purposes and would even be sufficient for anyone that had never been there before because it is obvious where to camp once you get close.  However, close by at Google map coordinates: 43.446988, -109.543162 there are some petroglyphs (just up the hill mostly on the west side of the rocks) that simply would not be found if one was 200 to 300 yards away.

At first I assumed that the difference between to two formats was caused by Garmin's only accepting two decimal places under the "seconds" and I had to round off that last digit that the converter gave me.  But, that is not the case as I found out when trying to force the Garmin format to be more precise in pinpointing the exact location I had identified using Google Maps.  I have not nor do I really care to reverse this experiment since for most (if not all) my purposes either Google Maps and/or Garmin will get me "close enough".  But, at least now I know that there is an issue here - be careful.

Bill

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Some of the newer Garmins accept decimal degrees for those that might have them.

Edit: I just saw you have the 890. Try decimal degrees again. Format: 43.456592, -109.547743

I'll test again to make sure once this huge map update completes.

Edited by Jairon
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Jairon - 

THANKS! 

However, it is a slight bit more complicated than that.  First I had to change the "coordinate format" and the "datum" to "h ddd.dddddd" and "WGS-84" respectively.  Once that was done and "saved" I was able to do as you suggested and the location in Google Maps and the Garmin are very close.

Bill

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33 minutes ago, topgun2 said:

However, it is a slight bit more complicated than that.

Interesting! Mine seemingly works out of the box with decimal notation but I'm glad you found something that works!

My result with your location:

gps2.jpg.e761cb4351edc85e6b8a2231c4796346.jpg

If that is in fact the location you're attempting, the only thing I've done is update the device a few times while connected to wifi.

Edited by Jairon
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Yep - that's the spot.  

Interesting that your model will accept decimal format right out of the box.  My nuvi 2797 which is about 4 years old and now the new RV890 will not accept that decimal format without the adjustment I mention above - strange.

On the other hand we just might be talking about two connected but separate things here.  I just noticed that you use the "search" function to input the decimal coordinates while I was trying to enter coordinates via the "where to/coordinates" function.  Your way seems easier and quicker than the way I was doing it, but, I'm still surprised that these two functions aren't the same.

Bill

2017 Ford F150 Lariat 3.5EB FX4 Max Towing 2016 Oliver Elite II - Hull #117 "Twist"

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