6

I need to know for example, heights of bridges/fly-overs from the land surface (just to know there is an elevated structure). How and where from can I get this data (preferably for EU)? Any open source databases/ any 3d maps with this data?

  • Just to confirm, you're looking for more than just topological elevation data, correct? You could figure out elevated structures from topological data, but you're look for a source that's already done this, correct? – Barry Carter Jan 15 '16 at 16:27
  • Yes, I was looking or elevation data of human constructions(more specifically road and bridge elevation data). No, from what I gather, topological data only gives me land elevation. Using google maps, I can visually determine an elevated platform/road but can not see any change in the elevation height on that platform and a point just next to the platform on the land surface. Please correct if I am mistaken. – user750066 Jan 16 '16 at 17:20
  • When I used a .BIL file to map Albuquerque's elevation, the raised highways (I25 and I40) were clearly visible, so I think topological data (at least the kind I've found) does include structural height, since it considers the top surface of a structure as "land". Of course, you need fairly high resolution to see the smaller structures. – Barry Carter Jan 16 '16 at 17:48
  • Hello Barry, Can you help me with the source for the .BIL files ? Do yu use some professional maps? Else if the bin resolution is 30m*30m, I cant understand how would elevation data for that bin help differentiate between an elevated road and the land surface... – user750066 Jan 17 '16 at 19:02
  • for England there is Lidar (DTM/DSM) up to 50cm resolution more info environment.data.gov.uk/ds/docs/… but you can extract height information out with some GIS software processes bases on it's refective properties (concrete can be detected). – Mapperz Feb 6 '16 at 19:55
3

There appears to be a US government program to map structural heights, suggesting that such a thing isn't already available. Quoting http://nationalmap.gov/3DEP/

The 3D Elevation Program (3DEP) initiative is being developed to respond to growing needs for high-quality topographic data and for a wide range of other three-dimensional representations of the Nation's natural and constructed features.

You can find existing elevation data at:

http://viewer.nationalmap.gov/basic/?basemap=b1&category=ned,nedsrc&title=3DEP%20View

or by clicking on the "Get Elevation Data" link at http://nationalmap.gov/elevation.html

The maps here are 1/9 arcsecond per pixel, which is right about 10 feet per pixel in latitude.

http://nationalmap.gov/3DEP/3dep_prodavailability.html notes that you can get 1m (about 3 feet) resolution digital elevation maps; however, it appears that this data isn't available online and that you must make a special request for it.

Of course, you're looking more for EU data. The US government does have some of this too: https://lta.cr.usgs.gov/elevation.html and http://hydrosheds.cr.usgs.gov/data.php but it seems even the best such data is 3 arcseconds, or about 90 feet per pixel, which might be enough to miss structures.

  • Hello Barry, thanks for the message, I downloaded map files from store.usgs.gov which turn out to be pdf files. These are not really helpful as I still can not access the elevation measurements of constructions(elevated roads, etc). Am I missing something? Or does it being me to what you quoted: 3D topographic elevation is under development...? – user750066 Jan 19 '16 at 16:48
  • Sorry, I meant that is was under development, so such a thing probably doesn't exist yet (since there's no need to develop something that already exists). The data you want to download is from the other sources I mentioned, but store.usgs.gov should have BIL files. Let me know what files you want to download and/or what process you used to get the files. You have to click on the "download" link, not on the name of the map itself. – Barry Carter Jan 19 '16 at 16:55
  • For checking what sort of information is available and whether I could really use it, I tried downloading data from store.usgs.gov by going to "Map Locator & Downloader" and then randomly zooming on to a city, placing a marker, clicking on the marker and choosing one of the latest data sources and then downloading the selection from the cart. (eg.: Stuarts Draft US Topo 7.5X7.5 GRID 2013 30.57MB). All it downloads is a zip file with a pdf in it. Any any chance is it that the data(BIL files) you are talking about is not available from other countries or is restricted? – user750066 Jan 21 '16 at 9:58
  • My apologies. I've now corrected the links. As a note, USGS is doing maintenance that was supposed to end 5m ago, but may still be in progress, based on the popups I'm getting. – Barry Carter Jan 21 '16 at 20:06

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.