Coordinates don't match?

[+needadietcoke]

(Be gentle- we are new at this).

 

I borrowed a Magellan SPort Track Pro from my neighbor and my kids and I began geocaching. My 12 YO was so enamoured that I bought a used Garmin eTrex Legend C. Here's the problem:

 

I know the Magellan is accurate because we have found several caches, but the coordinates do not match up at all (disregarding the decimals) and I don't know what setting to change or if I bought a dud.

 

For example: when the units are next to each other they read

 

Magellan 39 degrees 41.578 N

111 degrees 25.905 W

 

Garmin N 40.41768 degrees

W 111. 82593 degrees

 

The altitudes don't match either, but they DO match when they are tracking speed of movement. HELP!

[+coggins]

I would first make sure that both are set to the same datum. WGS84 being a good choice. Next I would change the Garmin from ddd.ddddd° to ddd°mm.mmm

Edited October 18, 2008 by coggins

[jholly]

Plus the Magi is showing DD MM.MM and the Garmin is showing DD.DDD. Go into the setup menu, the units sub menu to change the display. GC.com uses DD MM.MMM so you probably want both units set to that. And was pointed out in the previous post, the most likely problem is your units are set to different datums.

 

Jim

[+Cardinal Red]

I actually LOOKED at the numbers. They make no sense. Yes, they are different formats. But they are not just a different format, they are different coords. More than 50 MILES apart. Can anyone point out a format mismatch that can explain 50 MILES? I think not.

[+needadietcoke]

OK- I went in and changed the formatting. I wasn't letting that bother me but I thought the numbers should be the same. After changing the formatting and checking I put the GPS back in the exact same place it was last night and checking the datum (it was already set to that datum), now I have a completely different reading that is still wrong. Now it says 40 degrees 25.058 N and 111 degrees 49.555. Now I am MORE than 50 miles off!

 

Any more advice?

[+needadietcoke]

Well, I did a reset and things are a lot closer now. Still off, but within 100 feet. I'm afraid this may kill our joy of geocaching. My kids aren't THAT intense! And neither am I. Thanks for your help.

[+Cardinal Red]

Well, I did a reset and things are a lot closer now. Still off, but within 100 feet. I'm afraid this may kill our joy of geocaching. My kids aren't THAT intense! And neither am I. Thanks for your help.

 

Well, at least 100 feet is now in the ball park. 100 feet off of what? The Magellan? Yes, you found some caches with the Magellan, but is IT set to WGS84? Do you know you can check your GPS against a local Benchmark (note: not all Benchmarks are created equally). I tracked one down many years ago and was very impressed with how close to the Benchmark my Ground Zero was.

 

After the reset, how long did you let the GPS acquire data? It takes about 20 minutes to totally replace/update stale data. If it has been a long time since that used Garmin has been on (with a satellite lock) for a solid half hour, your data could be stale.

 

How many satellites do you have for your position fix? What is the estimated accuracy? Are you utilizing WAAS?

 

If all else fails: Cross your fingers, Knock on wood, Put a four leaf clover in your pocket, Throw a pinch of salt over your shoulder, Hang a horseshoe over your door, Carry a rabbits foot, Step on your shadow ... Well, you get the idea.

 

Edited because I usually spell "satellites" wrong.

Edited October 18, 2008 by Cardinal Red

[+luckybobb]

We have a explorist 100 and a etrex legendCX and they are always off by a little bit between the two of them.

[+GeekBoy.from.Illinois]

We have a explorist 100 and a etrex legendCX and they are always off by a little bit between the two of them.

 

We have 2 Magellan explorist 600 units, plus a Garmin 60Cx and a Garmin Colorado 300. None of the units ever seem to show the same coordinates for the same place. They are all generally within the EPE ranges of each other, so they do seem to agree close enough.