Messages

1

TopoFusion Pro / Re: DEM gives zero elevation? Can't figure it out.

« on: July 04, 2015, 10:23:09 AM »

Of course as soon as I posted this after hours of trying to figure it out, finally saw the "DEM Source" box under Climbing Analysis.

So I switched to "Download/cache" and --- bingo bango!

2

TopoFusion Pro / DEM gives zero elevation? Can't figure it out.

« on: July 04, 2015, 10:18:24 AM »

What am I doing wrong?

Some tracks can be corrected with DEM but others, or just parts of others will go to zero elevation when using the same feature.  The tracks are a mix of drawn by hand and actual GPS taken from a Garmin 510 unit.

Attached a file that when corrected displays a large chunk of missing elevation if anyone wants to try it and gets different results.

Thanks in advance - Matt

3

Feature Requests / Re: Data for a Selection

« on: January 25, 2012, 07:50:00 PM »

I know is the quite old, but any other ways to do this?  I most often find myself wanting a function like this when I want to time/measure a section of a long ride that coincided with riding in a group or split certain sections of track to view singletrack vs doubletrack etc.  Certainly the feature I'd love to see added most.

I've had difficulty doing the same thing by cutting the tracks in two or more sections as there doesn't seem to be a way to see the data in a summary format without saving each part of the track as a separate track which is also a bit labor intensive.

4

TopoFusion Pro / Re: Elevation comparisons between Edge and eTrex

« on: October 07, 2011, 05:21:18 PM »

If anyone is curious, here are two files from my most recent ride.

Edge shows 1161ft online, but in TF 2240, corrected with DEM to 1093.
eTrex shows 400ft online, 880 in TF, corrected with DEM to 932.

I think Scott is right regarding the Edge accumulating more noise.  I need to set the eTrex to record "Most Often" as the difference can be huge.  In this 10mi sample the Edge recorded 3932 points vs the eTrex's 882 so there is likely a ton of false evelation data (also the reason the eTrex recorded a shorter distance I'm sure after zooming in for detail).  I think elevation data would also be much closer if eTrex was capturing every second instead of how it is set currently.

5

TopoFusion Pro / Re: Elevation comparisons between Edge and eTrex

« on: October 06, 2011, 06:14:30 AM »

Thanks for the reply Scott.

The Edge 305 does have a barometric altimeter.  It seems correct most days but far off on others.  I've only noticed the net elevation differences at my start and stop points on 6+ hr rides that either start pre-dawn or move into the late night where temps may change 20-30 degs.  Who knows.

I'll continue to use the DEM button and trust those numbers as they seem most accurate after loading past tracks of the same trails and correcting.

6

TopoFusion Pro / Elevation comparisons between Edge and eTrex

« on: October 03, 2011, 06:07:49 PM »

Went on a ride yesterday with my trusty Garmin Edge 305 and brand new Garmin eTrex 30 to compare the two.  Predicatbly, they roughly recorded the same track over 22 miles.  What I wasn't expecting was the elevation numbers.

When I uploaded to Garmin Connect I got 990 ft (eTrex) and 2427 ft (Edge).  Knowing those numbers never seem to be "correct", I exported to TF and got more confused with 1722 (eTrex) and 4922 (Edge).  I looked here on the forums for awhile and read through the manual, finally found the "Correct elevation using DEM" button and got 1690 ft (eTrex) and 1863 ft (Edge).

So, which is "correct" and why?  Why such different initial numbers from two units?  Playing around with some of my older tracks I see a wide variety of swings from very close to original TF reading to 50% gain and 50% loss using the same process above.

Another anomoly which I have seen before generally when riding in changing weather (I think) is that the start and stop points should have read the same eleveation but instead saw a steady increase in the elevation overall so ended up higher than I started in the exact same spot (disappears after correcting using DEM).  Barometric pressure changes affecting the units?

Thanks for any insight!