[GRASS-dev] Re: [GRASS-user] srtm plus format and European bathymetry

[Michael Barton]

That's great Carlos. I'll try this out with the srtm plus files I have.

Michael


On 10/13/07 8:32 AM, "Carlos "Guâno" Grohmann" <carlos.grohmann at gmail.com>
wrote:

>> From an older post
> 
> (from Markus, I guess)
> 
> 
> Example:
>  r.in.bin -sb input=e020n40.Bathmetry.srtm output=e020n40_topex
> bytes=2 north=40 south=-10 east=60 west=20 r=6000 c=4800
>  r.colors e020n40_topex rules=etopo2
> 
> Enjoy
> 
> 
> Carlos
> 
> 
> On 10/13/07, Maciej Sieczka <tutey at o2.pl> wrote:
>> Michael Barton wrote:
>>> Ultimately, I'm trying to locate bathymetry off the coast of Europe to
>>> create a DEM of Pleistocene Europe during times of low sea level (i.e.,
>>> -300m).
>>> 
>>> Following the FreeGIS.org link off the GRASS download data page, I found a
>>> site with "STRM30 plus" that combine 1km SRTM with bathymetry
>>> <ftp://topex.ucsd.edu/pub/srtm30_plus/data>. This seems just what I need.
>>> However, I can't figure out the format or how to import it into GRASS. The
>>> files show up like " w020n90.Bathmetry.srtm". I've tried r.in.gdal and
>>> r.in.strm to no avail. I thought maybe the files were compressed and tried
>>> to uncompress them without luck.
>>> 
>>> Can anyone suggest what to do with these files?
>> 
>> Michael,
>> 
>> ftp://topex.ucsd.edu/pub/srtm30_plus/README.V2.0.txt:
>> 
>> <snip>
>> DATA FORMATS
>> Data are provided as binary integers in exactly the same
>> format as SRTM30.  The files must be uncompressed with gzip
>> and are 16-bit big endian byte order.
>> </snip>
>> 
>> Other than they don't seem gzipped actually, the information
>> looks correct. These are 16 bit signed integer binary grids.
>> 
>> You can use r.in.bin, or r.in.gdal if you create appropriate
>> header files (see r.in.srtm script for inspiration; note it
>> cannot work with 30" SRTM data as it is now - currently it
>> supports only 3" and 1" SRTM tiles). In the presence of
>> properly formatted *.hdr GDAL supports such binary grids
>> with "ESRI .hdr Labelled" driver [1]. In
>> ftp://topex.ucsd.edu/pub/srtm30_plus/ermapper_headers there
>> are ERmapper header files, which I suppose can be used to
>> prepare their GDAL-understandable version.
>> 
>> [1] http://www.gdal.org/frmt_various.html#EHdr
>> 
>> Maciek
>> 
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> 

__________________________________________
Michael Barton, Professor of Anthropology
Director of Graduate Studies
School of Human Evolution & Social Change
Center for Social Dynamics & Complexity
Arizona State University

phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton