SRTM ver. 4: Used in Locus? Difference from ver. 3? Where to get it?

popescu shared this question 4 years ago
Answered

It says at the CGIAR-CSI website ( http://srtm.csi.cgiar.org/ ) that a new SRTM ver. 4 is now available and that this update is an "sifnificant improvement" in the quality of the data. But:

  1. The files in the link are from 2009, so the "now available" seems slightly outdated
  2. The data are available in huge blocks (one for the whole NE hemisphere)

I was just wondering whether Locus uses this SRTM4 version when I ask for altitude and choose to get it online and Locus downloads a whole tile of SRTM data from somewhere.

  • If yes, where does Locus download the current SRTM4 data from?
  • If no, two other questions:
  1. Is the SRTM4 really that significantly better? Is it worth it trying to get it? What's new?
  2. If it's worth it and not currently the same stuff I get from Locus automatically, where to get it just for the Central Europe? (No need for a 1.1 GB file covering the whole NE hemisphere including half of Africa)

Comments (3)

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Hi,

Locus doesn't use the CGIAR-CSI SRTM4. Source of elevation data is ViewFinderPanoramas project from Jonathan de Ferranti, please see: http://www.viewfinderpanoramas.org/dem3.html We also used GRASS SW for filling the holes in data. I can remember that ViewFinderPanoramas data were discussed as the best solution for global elevation data but we didn't performed any deeper comparison.


Please see also section "Other DEM sources" at http://www.viewfinderpanoramas.org/dem3.html where is written about CGIAR-CSI SRTM4 and ViewFinderPanoramas data


To you additional questions:

1. I'm not sure if I can give you relevant answer but from my opinion are ViewFinderPanoramas even better then CGIAR-CSI SRTM4

(especially for mountain areas).


2. If you want to download data in block see the ViewFinderPanoramas download page:

http://www.viewfinderpanoramas.org/Coverage%20map%20viewfinderpanoramas_org3.htm

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Thanks for the swift and complex reply, Peter. I'm going to stick with the data Locus dowloads by default.

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Fine :)