[gdal-dev] gdalwarp on large files

[Laura Toma]

Even,

I have the setup configured so that it  does not disconnect on its  
own.   There was something about gdalwarm handling large files.     
After some delay installing  the latest release  of gdal (gdalbuildvrt  
is not available in the earlier versions),  I got it to work. Both  
gdalbuildvrt and gdal_translate finished  fast (less than an hour) and  
now I have a 432001P x 40801L  raster.

Thanks a lot!

-Laura


On Jun 1, 2009, at 2:30 PM, Even Rouault wrote:

> Laura,
>
> From the error message, I guess you are running gdalwarp on a remote  
> server
> through a ssh connexion. There's probably a timeout that occurs  
> since your
> operation takes hours. You should check the ssh options of the  
> client/server
> for that.
>
> In your use case, if you just want to create a mosaic of SRTM files  
> and not
> really warp them, you'd better use gdalbuildvrt to create quickly a  
> VRT file
> (XML-based) and then translate it to geotiff. This should run much  
> faster
> than gdalwarp. But the 432001P x 40801L output size will remain. As  
> it is
> huge, it will also likely take some time !
>
> gdalbuildvrt mosaic.vrt *hgt
> gdal_translate mosaic.vrt mosaic.tif
>
> If you only use the mosaic with GDAL enabled tools, you can skip the
> gdal_translate step. That will save space (17.6 GB!) and time (a few  
> seconds
> v.s. several hours).
>
> Best regards,
> Even
>
> Le Monday 01 June 2009 19:58:44 Laura Toma, vous avez écrit :
>> Hi,
>>
>> I am trying to create a large DEM from SRTM3 data.  I have a folder
>> 'australia' which includes 1060 .hgt tiles downloaded from
>> 'rome0srp01u.ecs.nasa.gov/', and I am trying to create a tiff for all
>> the tiles in this folder.
>>
>> I have tried to run 'gdalwarp'  several times and every time the
>> server gets reset (see below) after  processing the first .hgt file.
>> The tiles are not that large (i think i3600x3600), but processing the
>> first tile takes hours.
>>
>> Has anybody tried anything similar? Am I doing something wrong?  Any
>> advise would be greatly appreciated.
>>
>> thanks,
>> Laura
>>
>>> gdalwarp *hgt srtm_mosaik_australasia.tiff
>>
>> Creating output file that is 432001P x 40801L.
>> Processing input file S11E119.hgt.
>> Using internal nodata values (eg. -32768) for image S11E119.hgt.
>> 0...10...20...30...40...50...60..Read from remote host cod:  
>> Connection
>> reset by peer
>>
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>
>