[mkgmap-dev] "Small" SRTM1 files and DEM maps

Thu Apr 16 08:18:16 BST 2020

Hi Carlos,

are you talking about geotiff format? I think someone documented how that format can be converted to *.hgt.
Can you post a link to such a file?

Gerd

________________________________________
Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag von Carlos Dávila <cdavilam at orangecorreo.es>
Gesendet: Montag, 13. April 2020 14:08
An: mkgmap-dev at lists.mkgmap.org.uk
Betreff: Re: [mkgmap-dev] "Small" SRTM1 files and DEM maps

Hi Gerd
They are downloaded by phyghtmap. This is what I found digging into
phyghtmap files:
|def getSRTMFileServer(self, resolution, srtmVersion):||
||        if srtmVersion == 2.1:||
||            return
"https://dds.cr.usgs.gov/srtm/version2_1/SRTM{0:d}".format(resolution)||
||        elif srtmVersion == 3.0:||
||            if resolution == 1:||
||                urlRe =
"https://earthexplorer.usgs.gov/download/8360/SRTM1{:s}V3/GEOTIFF/EE"||
||            elif resolution == 3:||
||                urlRe =
"https://earthexplorer.usgs.gov/download/4960/SRTM3{:s}V2/GEOTIFF3/EE"||
||            return urlRe|
They should come from the second URL above.

El 13/4/20 a las 8:24, Gerd Petermann escribió:
> Hi Carlos,
>
> sorry for the late response. I found no hint on the phyghtmap page http://katze.tfiu.de/projects/phyghtmap/
> regarding a new format for srtm data. The hgt format is not compressed. Do you know from where these 12.4 MB files came from?
>
> Gerd
>
> ________________________________________
> Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag von Carlos Dávila <cdavilam at orangecorreo.es>
> Gesendet: Samstag, 11. April 2020 17:09
> An: Development list for mkgmap
> Betreff: [mkgmap-dev] "Small" SRTM1 files and DEM maps
>
> I use phyghtmap to build contour lines and also to download hgt data
> that I then use to build DEM maps with mkgmap. For a long time, SRTM1
> files (and also VFP1) have all been ~24.7 MB in size, but lately (I
> don't remember since when) SRTM1 are also served as 12.4 MB files.
> phyghtmap is able to generate contour lines from those small files, as
> they seem to contain the same information but with a different
> compression ratio, but mkgmap fails to read them, and report them as
> missing. Would it be possible to get support for such files in mkgmap?
> _______________________________________________
> mkgmap-dev mailing list
> mkgmap-dev at lists.mkgmap.org.uk
> http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev
> _______________________________________________
> mkgmap-dev mailing list
> mkgmap-dev at lists.mkgmap.org.uk
> http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev

_______________________________________________
mkgmap-dev mailing list
mkgmap-dev at lists.mkgmap.org.uk
http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev