Oregon 200 way off

[+GDSKWats]

I'm relatively new with this GPS, and GPS's in general. I use the Oregon 200 (which up til now has been quite good) and usually have a Blackberry with Geocache Navigator going as well.

We're driving through town the other day and I notice that the Oregon is showing our path is about 15 metres parallel to the road. My friend who has an older Garmon 60Csx(?) says I may need to recalibrate the GPS but we couldn't figure out if that was possible.

Also the distance to cache on approach was way different than the Blackberry and way off the mark much of the time.

How do I rectify this problem??

Thanks

[+dfx]

you can't calibrate the GPS. you can calibrate the compass, but that's a seperate issue.

 

the usual suggestion: check the datum, it should be WGS84.

 

you seeing the track being off the road but parallel to it could be simply because the map you're using is off, or the road is simply wider than 15 meters. you'll never see the track as being right on the road unless you enable the "lock to road" mode, but you don't want that for geocaching.

 

your description of the distance to the cache being "way off the mark" doesn't give enough information to draw any conclusions.

[+coggins]

We're driving through town the other day and I notice that the Oregon is showing our path is about 15 metres parallel to the road.

 

How do I rectify this problem??

Use better maps.

[+GDSKWats]

Use better maps.

 

It has Garmin Topo Canada. I'm thinking that should be OK?

 

I'm driving in downtown St. Catharines ON. King Street (that I'm on) and Church St. run parallel. The path is pretty much right between the two.

 

Caching that afternoon, my Blackberry is giving me fairly accurate compass readings. For example, when it says the cache is 150 m away, the Garmin may say 325 m away, then changes erratically from time to time as well. It's not like that 15 m difference we were seeing as we were driving is consistently reflected when caching. Then it may suddenly start giving fairly accurate readings as well.

 

If I just had the Garmin, caching would be very difficult and frustrating.

 

How do I check the datum? (I'm sorry, I don't even know what that means)

[+PDOP's]

... We're driving through town the other day and I notice that the Oregon is showing our path is about 15 metres parallel to the road.

Depending on the view of the sky at the time that's not an unreasonable error. For road navigation you might want to selcct "Lock on road" (setup=>routing=>Lock On Road=>Yes) but that can be confusing when finding caches off road.

[+Uplink]

A map datum is a grid system for presenting a 3D world with 2D coordinates. all maps and "map sets" like the one found in your Garmin reference a "map datum". Geocaching default is WGS84. Many paper Topographic maps use NAD27. The military uses UTM which does not use latitude and longitude. I thought about looking up how to set the datum on a Garmin Oregon for you, but you should learn how to look it up yourself.

 

Your typical Garmin GPS is more accurate than many map sets. Garmin buys data from various vendors to use in their map sets, and the quality varies. If the data for the Ontario map set is imprecise for various reasons, you will see errors on your moving map. 15 meters is actually not bad. People forget that prior to 2001, the GPS signals were degraded to an accuracy of +or- 100 meters. The day they turned that off was the day Geocaching was born.