Where's the cache?

[Guest RXQ]

Let me see if I can explain the problem

 

I go to a Geocache page which tells me that the cache is at

 

N 42 deg 47.321 min W 71 deg 45.534 min(WGS 84)

 

I have a topo map which is NAD27 and uses UTM, so I click on

"Covert to NAD27 or UTM"

This takes me to JeEep.com. On the web pages it tells me that the Cache is at

 

19 274304E 4740819N (NAD27)

 

So I want to see where it is on the topo map the cache is so I click on Topozone. On this web page it tells me that the cache is at

 

19 274344E 4740827N (NAD27)

 

Now I enter the Geocache coordinates into my Garmin GPS12 and change the setting from hddd mm.mmm' WGS 84 to UTM NAD27 (CONUS). This tells me the cache is at

 

19T 274302E 4740831N

 

So this is what I have

 

JeEep.com 19 274304E 4740819N

Topozone.com 19 274344E 4740827N

GPS12 19T 274302E 4740831N

 

My question: Where's the cache?

Has anyone else have problems using JeEep.com UTM NAD27 coordinates?

 

Here are some other examples from other geocache pages.

 

GC5 N 46 deg 06.814 min W 122 deg 19.72 min(WGS84)

 

UTM NAD27

JeEep.com 10 551967E 5106690N

Topozone.com 10 551875E 5106670N

GPS12 10T 551970E 5106689N

 

GC28C N 31 deg 43.265 min W 83 deg 06.633 min (WGS84)

 

UTM NAD27

JeEep.com 17 300004E 3511252N

Topozone.com 17 300016E 3511272N

GPS12 17R 300010E 3511251N

[Guest Moun10Bike]

I can't for sure say what the problem is with JeEep.com and Topozone.com, but it looks like some sort of conversion error. I'm getting the exact same values as you. In any case, the correct location is the one that your GPS is reporting. I would set your GPS to WGS 84 and hddd mm.mmm, enter the coordinates given on geocaching.com, then change your GPS to UTM and NAD27. Use this value for plotting.

[Guest bacpac]

n your GPS and the numbers change automatically. Why are folks messing with this Jeep.Com and Topozone conversion. Am I missing something?

[Guest Moun10Bike]

quote:

---

Originally posted by bacpac:

What am I missing here?

---

 

I assumed that he wanted to be able to easily plot position manually on his paper maps. If no plotting is involved, then I agree -- this seems like a lot of unnecessary steps.

[Guest bacpac]

I guess I am still missing something.

 

RXQ has a GPS. Why not select the WGS-84 datum, enter the Geocashing.Com coordinates and then change the GPS map datum to match his map?

 

I used to suspect that the map datum and format was poorly defined in GPS manuals. Now I am certain.

[Guest Moun10Bike]

quote:

---

Originally posted by bacpac:

Why not select the WGS-84 datum, enter the Geocashing.Com coordinates and then change the GPS map datum to match his map?

---

 

Um, unless I missed something myself, that's precisely what I suggested he do!

[Guest RXQ]

I was under the impression that coordination translations was a simple algorithm that a computer could handle. The first thing I wanted to do was determine if it was My GPS or JeEep.com that had the source of the discrepancies.(Thanks Mount10Bike) Since I was under the impression that The JeEep.com UTM(NAD27) was correct I had entered those coordinates into my GPS since I use UTM(NAD27). I notice the discrepancies because when I go GPSing I take notes when I capture a waypoint. (Which Satellites, their strength and EPE as well as time and date). When I came back from geocaching I notice the discrepancy.

 

The next question is why does Geocache.com offer conflicting information without a warning? That we should ONLY enter the Geocache.com (WGS84) coordinates. After all we do want people to find this cache.

 

Bacpac. "What I'm I missing?" My father in law says that all the time. He can't remember whether or not he lost something. He says the Ginkgo Biloba helps him out a lot.

[Guest bacpac]

RXQ,

 

What were the coordinates on your GPS when you found the cache?

[Guest fairbank]

My question: Where's the cache?

Has anyone else have problems using JeEep.com UTM NAD27 coordinates?

 

Yes, the first time I used them I found a problem and haven't used it since. I use either my GPS or this site which you will find agrees with your GPS.

 

http://www.ualberta.ca/~norris/navigation/maptran.html

[Guest RXQ]

Bacpac,

The first cache I used JeEep.com UTM NAD27 and was only able to find it because of the tracks in the snow. The second one, I entered the geocache.com WGS84 and converted using my GPS. When I found it, it was exactly the same as geocache.com. I wasn't sure if discrepancy was in my GPS or JeEep.com or topozone.com. That only way to tell is if others get the same discrepancies.

[Guest bacpac]

RXQ,

 

Thanks for the update. Your response confirms that my method of converting map datums and formats via the GPS is the correct one. I haven't missed a thing:-)