Accurate Position but SHIFTED west.

[DaPhotoGuy]

I have a VISTA with some US Roads and Recreation maps loaded. When I drive around in my car and look at the tracks recorded in the log, the tracks match the shape of the roads perfectly EXCEPT that they are shifted about 200 feet to the west of where they should be. Is there a way to calibrate the location the GPS shows you to be at versus where you KNOW you are on the map?

 

daphotoguy@hotmail.com

[+Stunod]

I doubt your entire map is shifted. Most of the maps have errors in position of some streets (my Meridian shows me off-roading for about 10 miles on my way to work!).

 

Drive around a bit more to see if it is just an error on the location of some streets on the map before you assume your GPSr is defective.

 

"Just because I don't care doesn't mean I don't understand."

[azog]

I just loaded maps into my Legend, and it does the same thing.

 

While displaying a map, choose the options icon, and select "Set Up Map". Now turn on/off "Lock on road".

 

However, beware that if you enable this setting, it may have adverse affects on your geo-hunting.

 

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Do not answer a fool according to his folly, lest you be also be like him.

[+Team GPSaxophone]

I had just turned on my Etrex Venture and it showed me near a cache that I hadn't found yet. Before setting off to hunt for it, I zoomed out and discovered that I was just outside of Colorado Springs, CO when in fact, I was on a hunting trip about 300 miles from there! It said Ready to Navigate. Accuracy 48 feet

[azog]

Were you at CO Springs the last time you used your eTrex? The manual says that if you've moved more than 600 miles since the last time you turned the unit on, you need to retrack.

 

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Do not answer a fool according to his folly, lest you be also be like him.

[+Planet]

But usually it's because I'm zoomed in too close. Try zooming out a notch or two.

 

Cache you later,

Planet

 

"It doesn't matter whether you're going somewhere or nowhere, whether you're doing something or nothing. If you're doing it in a boat it's the best time ever!" -Water Rat from "The Wind in the Willows" by Kenneth Grahame (a book I picked up in a cache)

[+Team GPSaxophone]

quote:

---

Originally posted by azog:

Were you at CO Springs the last time you used your eTrex? The manual says that if you've moved more than 600 miles since the last time you turned the unit on, you need to retrack.

---

 

Actually no, I had used it for 2 or 3 days in northwest Colorado after passing through the Springs. When I turned it on, it showed me about halfway between the "toolman cache" and "casse aviation cache" but not even close to I-25.

[+GEO*Trailblazer 1]

My theory on this is that the earth is moving from the east to the west at a great speed 1 second can mean approx. 100 feet more or less so unless you have a unit that can keep locked on in any condition you loose seconds.To explain this in great detail I can not do at this time. You can use your own Triangulation system in your GPSr to get better accuracy,the Satelites use the waypoints that you have programmed to fix your location so if you have a grid around the area you get better results especially if you have third order or better points,Quadrangle of the true variation of the point.The south line gives you the base line.. ect. ect.You also have to remember that these maps that we are using have been redrawn several times the NGS has adjusted to the Geoid this will cause random errors everywhere the technology that we have has never been used to this degree of acuuracy so as you can see we are all of a little bit he he. For a further look see Annual Wesward Slippage or the proper motion of the Stars.This might explain a little more. http://www.triplehood.com/triplehood/update02.htm http://csep10.phys.utk.edu/astr162/lect/motion/proper.html

 

When all else fails Geotry again.

 

[This message was edited by Trailblazer # 1 on November 14, 2002 at 10:49 PM.]

[Kerry.]

#1, yes you certainly are lost

 

Cheers, Kerry

 

I never get lost everybody keeps telling me where to go

[+Pharisee]

This may (or may not) have anything at all to do with it but my Ledgend tracks perfectly on the the roads of the European Metro Guide but if I run off the edge of the loaded maps (8Mb is NOT enough!!!) and onto the factory loaded European Base Map, the roads are miles out. In fact, they just appear as straight lines joining one place to the next and are pretty much useless for navigation.

 

John

 

*************************************************

 

To the optimist, the glass is half full. To the pessimist, the glass is half empty. To the engineer, the glass is twice as big as it needs to be.

[stonefinder]

guess that will have to buy a vista, thought about a ledgend, and went for more memory in the vista

 

have vista will travel, I always know were I am because I have my vista

[stonefinder]

guess that you will have to buy a vista, thought about a ledgend, and went for more memory in the vista

 

have vista will travel, I always know were I am because I have my vista

[+Olar]

quote:

---

Originally posted by DaPhotoGuy:

I have a VISTA with some US Roads and Recreation maps loaded. When I drive around in my car and look at the tracks recorded in the log, the tracks match the shape of the roads perfectly EXCEPT that they are shifted about 200 feet to the west of where they should be. Is there a way to calibrate the location the GPS shows you to be at versus where you KNOW you are on the map?

---

This is just a stab in the dark but I wonder if you have the map datum on your GPSR set differently then that on Mapsource it will create this problem?

Cheers, Olar

 

"Pi 'r not square, Pie 'r round you dummy!"