Author Topic: Google Earth coordinates not matching my GPS?  (Read 3004 times)

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Offline Lives2hunt

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Google Earth coordinates not matching my GPS?
« on: June 02, 2012, 07:56:43 AM »
My Garmin GPS76C is set on hddd°mm.mmm'  and the map datum is NAD27 CONUS. My lease is on Google Earth and the numbers don't match my GPS. For example my GPS shows N 36°07.503'  by W096°32.260 but on Google Earth it doesn't match it. Any ideas or suggestions on how to correct my GPS to match theirs?
Will hunt for food.

Offline Siskiyou

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Re: Google Earth coordinates not matching my GPS?
« Reply #1 on: June 02, 2012, 06:57:10 PM »
 I just ran a little test on some waypoints I have generated in the past using a Garmin 76Cx.  They match real good with Google Earth. If you have not, make sure that your settings in Google Earth match the setting in you Garmin.  In Google Earth you can chose the format that is compatible with your gps.  Go to Tools>Options>Show Lat/Long>and select the units that match your gps;  In this case Degrees, Decimal minutes.

I have used Google Earth a lot along with my gps.  I have made up a binder with Google Earth Images that I have printed on photo paper.  When working with hunting partners the view helps keep us on the same page.

I have the units in Google Earth and my gps set on hddd˚mm.mmm’
There is a learning process to effectively using a gps.  Do not throw your compass and map away!

Boycott: San Francisco, L.A., Oakland, and City of Sacramento, CA.

Offline Lives2hunt

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Re: Google Earth coordinates not matching my GPS?
« Reply #2 on: June 03, 2012, 04:20:52 AM »
Thanks for the reply.

When I put in my physical address which is deleted by poster Tulsa OK. my Garmin GPS 76C set on hddd°mm.mmm' shows the following:
N Deleted by poster. with the elevation of 738'.

Google Earth (set on Degrees, Mnutes & Seconds,) shows that location as deleted by poster. with the elevation of 738'.

As I understand it the longitude on my GPS is pretty close but the latitude is what concerns me. Any ideas or suggestions?     

Will hunt for food.

Offline Siskiyou

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Re: Google Earth coordinates not matching my GPS?
« Reply #3 on: June 03, 2012, 07:36:35 AM »
 You need to be using the same units of measurement on you gps and Google Earth.  A difference will show up if you mix them up.  It is like making apple pie with peaches. Taste good but not same.  One of the first things I do every fall when I get together is to make sure the units on everybody’s gps are the same.  When mixing units of measurement you might be off a few feet to a few hundred feet.  Your Map Datum should be set at:  WGS 84.  One year a hunting partner had been showing his gps to a grandchild and had changed his Map Datum to one in India.  That was like mixing scrambled eggs with rocks. ???
I just entered your lat/long rather than the address in Google Earth.  Looks like it put me in the backyard near or on the property line. ;)
Go to Main Menu>System>Enter>System Setup Page>WAAS/EGNOS IF DOES NOT SHOW NORMAL PRESS ENTER AND SELECT NORMAL.  This will allow you to take advantage of the corrected signal.  A quick check of the Satellite might answer this question.  If the signal bars display the letter (D) in the base of the bar you are receiving a corrected signal.
Suggestion:  Take your operating 76C out front to the junction of your driveway and the street.  Give your GPS a10 minutes to receive that maximum number of satellites.  I suspect you already know what a good average for you location is.  For example I am receiving 12 satellites on my 76Cx with 11 of them showing a (D) in the signal bar.  I am setting in our computer room with the shades drawn to keep the sun from heating it up.  The unit is currently showing 10 to 14 feet accuracy.  Remember we are not using survey grade gps units that cost many thousands of dollars;  And computer programs are used to correct the date the units collect.  To expect a recreational gps to provide the same level of accuracy is not realistic. 
Ten minutes seems like a long time, but in this case we are conducting a test, and we want the best data the unit can provide.  Normally in the field I just make a waypoint as I come across a big track while scouting.  Create a waypoint, and now enter the Lat long in Google Earth with space between the Lat and the long no & in there.
Different Units may give a slightly different reading, my 76cx is giving me N xx˚xx.344’  my 530HCX is giving me N xx˚xx.342 with accuracy of 17 feet.
With your new Lat/Long created out front enter it into Google Earth Search. 
I just entered mine from the 76Cx in the Google Earth Search and could almost feel the location pin strike my forehead; Amazing!
Are you using one of Garmin’s Mapping Programs?  In the past I have taken tracks and waypoints for my Garmin gps unit and downloaded it to my Garmin Topo program, and viewed it on Google Earth.  A nice item in this hunter’s toolbox.






http://www.gps.gov/support/user/mapfix/
There is a learning process to effectively using a gps.  Do not throw your compass and map away!

Boycott: San Francisco, L.A., Oakland, and City of Sacramento, CA.

Offline bilmac

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Re: Google Earth coordinates not matching my GPS?
« Reply #4 on: June 03, 2012, 01:07:03 PM »
Use UTM instead of Lat and Long. Military uses it. The units are in real units, meters, rather than the numbers in lat and long which are variable and therefore pretty much meaningless. Also there is only one way to write UTM, rather than the several different way to make lat long confusing.

Offline Lives2hunt

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Re: Google Earth coordinates not matching my GPS?
« Reply #5 on: June 03, 2012, 02:52:44 PM »
You need to be using the same units of measurement on you gps and Google Earth.  A difference will show up if you mix them up.  It is like making apple pie with peaches. Taste good but not same.  One of the first things I do every fall when I get together is to make sure the units on everybody’s gps are the same.  When mixing units of measurement you might be off a few feet to a few hundred feet.  Your Map Datum should be set at:  WGS 84.  One year a hunting partner had been showing his gps to a grandchild and had changed his Map Datum to one in India.  That was like mixing scrambled eggs with rocks. ???
I just entered your lat/long rather than the address in Google Earth.  Looks like it put me in the backyard near or on the property line. ;)
Go to Main Menu>System>Enter>System Setup Page>WAAS/EGNOS IF DOES NOT SHOW NORMAL PRESS ENTER AND SELECT NORMAL.  This will allow you to take advantage of the corrected signal.  A quick check of the Satellite might answer this question.  If the signal bars display the letter (D) in the base of the bar you are receiving a corrected signal.
Suggestion:  Take your operating 76C out front to the junction of your driveway and the street.  Give your GPS a10 minutes to receive that maximum number of satellites.  I suspect you already know what a good average for you location is.  For example I am receiving 12 satellites on my 76Cx with 11 of them showing a (D) in the signal bar.  I am setting in our computer room with the shades drawn to keep the sun from heating it up.  The unit is currently showing 10 to 14 feet accuracy.  Remember we are not using survey grade gps units that cost many thousands of dollars;  And computer programs are used to correct the date the units collect.  To expect a recreational gps to provide the same level of accuracy is not realistic. 
Ten minutes seems like a long time, but in this case we are conducting a test, and we want the best data the unit can provide.  Normally in the field I just make a waypoint as I come across a big track while scouting.  Create a waypoint, and now enter the Lat long in Google Earth with space between the Lat and the long no & in there.
Different Units may give a slightly different reading, my 76cx is giving me N xx˚xx.344’  my 530HCX is giving me N xx˚xx.342 with accuracy of 17 feet.
With your new Lat/Long created out front enter it into Google Earth Search. 
I just entered mine from the 76Cx in the Google Earth Search and cold almost fell the location pin strike my forehead; Amazing!
Are you using one of Garmin’s Mapping Programs?  In the past I have taken tracks and waypoints for my Garmin gps unit and downloaded it to my Garmin Topo program, and viewed it on Google Earth.  A nice item in this hunter’s toolbox.
Thanks you have resolved the problem. I really appreciate all your help on this. You're the man!






http://www.gps.gov/support/user/mapfix/
Will hunt for food.