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Question about elevation data download
Posted: Fri Jul 19, 2019 10:39 pm
by Caryllb
I have downloaded topo maps from several sources for one specific area to test an issue I am having with the elevation data download. I downloaded the USGS topo from Caltopo and also from USGS. Plus I downloaded the USFS topo for the same region from Caltopo as well.
I then create a path thru these tiles using each of these downloaded tile sets. When I look at the details for these paths I see the correct elevation plot for the start of the path. Then it goes to just a straight line for the rest of the path. It seems that the elevation data for a bunch of the tiles on all three map downloads is missing.
Is this an issue with the map source, i.e Caltopo or USGS? Do you have suggestions on how I can get elevation data downloaded using some other means whenever this happens? It just seems to be missing on some tiles, not on all. So I only need to fill in the data in some locations.
Re: Question about elevation data download
Posted: Wed Jul 24, 2019 12:05 pm
by Psyberia-Support
Hi,
The displayed map(s) and the elevation data are two distincts things.
The elevation data come from our servers and does not depends on the displayed map.
If the elevation data is missing at some locations, be sure that:
- You've checked the "Auto download elevation data" so the app can download missing parts;
- You're in a latitude between 56°S and 60°N.
At any time you can displayed the covered areas. More info here:
https://www.alpinequest.net/en/help/v2/elevations
Re: Question about elevation data download
Posted: Thu Jul 25, 2019 8:31 pm
by Caryllb
I'm still having issues with getting the elevation data to download. I have a large area of USGS topo maps already downloaded. I turned on the Elevation coverage display and notice that the elevation data for only some of the tiles was downloaded. So I double check that I have the "Auto download elevation data" checked and the "Use elevation data" checked. I then try to download that same area of USGS topos to see if I can get the elevation data to download. It seems to skip the USGS tiles that have already been downloaded, which is a nice since I don't want to download the same tiles I already have. However, I still don't get the missing elevation data to download. It seems that maybe it not only skips the USGS tiles that are already downloaded but also the associated elevation data as well even though the elevation data was not previously downloaded. Is there some way to force the download of just the missing elevation data?
Re: Question about elevation data download
Posted: Fri Jul 26, 2019 7:01 am
by Psyberia-Support
Hi again,
When you use the "Store complete area" tools, yes the application will skip map areas already downloaded.
But the elevation data is not part of this process, unfortunately you cannot download it with the "Store complete area" tool.
When "Auto download elevation data" is checked, the application will only download elevation data when needed.
If you want to preload the elevation data for a complete area, here is what you need to do:
- Display the "Elevation data coverage" layer so you get a good idea of which areas are covered;
- Zoom (or un-zoom) until zoom level 10/18 (for the default map), which is the zoom level from which the application will download elevation data when you move the screen center dot over an area with no elevation data;
- Move around the map until the area you need is all filled.
I agree that the "Store complete area" tool should do this job, this is unfortunately not the case for now.
Hope it helps
Re: Question about elevation data download
Posted: Fri Jul 26, 2019 7:02 pm
by Caryllb
Thanks so much for the tip. I was just not understanding how it worked. I thought I had to download an area and then the elevation data came with it. I didn't realize that elevation came as an entirely separate step. I finally figured out the steps you outlined here late yesterday afternoon.
As a suggestion it would be nice to have elevation download with the store area step as well. That would help alleviate some confusion at least for me that is.
Cheers