Accuracy? GPS Trip Info versus Delorme Topo 4 Trip Info

[turp182]

I'm using a Garmin eTrex Legend to create tracks of my hikes. I've only been using it a couple of weeks but I love it. Combine the track files from the GSPR with Delorme Topo 4 and I can create cool maps showing my hike along with hike stats.

Anyway, after I got home from a hike today I noticed that the trip distance on the GPSR was 9.38 miles while the distance in Topo (calculating the Profile for my imported tracks) came out to 10.36 miles.

There were quite a few blackout periods when the GSPR didn't have a clear view of the sky, I'm thinking that could be part of the problem?

So, which distance do you think would be the most accurate and why?

Thanks.

[bzachar]

Hi Turp,

Without seeing the actual track or route you took either one *could* be the more accurate one.

In general, the Topo track is probably the more accurate because:
-The GPSR lost lock when it didn't have a clear view of the sky so it didn't know every twist & turn you took.
-If you were hiking on uneven ground, Topo probably calculates terrain distance (includes ups and downs). Check the documentation. I use National Geographic TOPO! which does calcualte terrain distance.

I use my GPSR the same way, record a track and download when I get home. Some friends are taking us hiking in the White Tanks tomorrow... it will be our first time. When we get home I'll be able to see where were! HA!

Bill