rooots

Hmm...agreed, that looks pretty open according to satellite images. Well...it was just a guess... ;-)

Just a guess: could it be that the difference originates from Viking only using GPS data of the track to calculate vertical gain, while Garmin also uses barometric data to correct for GPS inaccuracies? That would also explain why in my first example, recorded mostly in forest, the relative difference is a lot larger, while with the second example, recorded in open alpine terrain, it is just a couple of %. Do you have tracks recorded under such different conditions as well?

Just a guess: could it be that the difference originates from Viking only using GPX data of the track to calculate vertical gain, while Garmin also uses barometric data to correct for GPS inaccuracies? That would also explain why in my first example, recorded mostly in forest, the relative difference is a lot larger, while with the second example, recorded in open alpine terrain, it is just a couple of %. Do you have tracks recorded under such different conditions as well?

I can confirm this, just compared some recent and old tracks and got for example, 417 vs. 292m and 1701 vs. 1593m. What device are you using? Mine are FR965 and 970. Until some while ago, I only used to see this when using "Apply DEM Data" to a track, where the total elevation gain would also depend on the density of trackpoints, even if neighbouring trackpoints were shown to have the same DEM altitude.

I can confirm this, just compared some recent and old tracks and got for example, 417 vs. 292m and 1701 vs. 1593m. What device are you using? Mine is FR965 and 970. Until some while ago, I only used to see this when using "Apply DEM Data" to a track, where the total elevation gain would also depend on the density of trackpoints, even if neighbouring trackpoints were shown to have the same DEM altitude.

Thanks, very much appreciated! I will test as soon as possible. Will the changes also be implemented in GTK3-WIP? Cheers, r.

You're right, it's a HTML file :-| When I try to d/l the ZIP file via the web browser, I'm getting an auth dialog and/or "access denied", so obviously with wget we're getting redirected. However, I'm wondering if the 3601x3601 px JPG files in the same folder are only previews, or if they could be used as DEM data as well? Anyway, your idea about adding an option for providing auth credentials in Viking sounds like the way to go.

Addendum: Looking positive: I can confirm being able to download an example file without the need for authentication using: wget https://e4ftl01.cr.usgs.gov/MEASURES/SRTMGL1.003/2000.02.11/SRTMGL1_page_2.html/N21E043.SRTMGL1.hgt.zip