[Gdal-dev] projection lost when translating HDF to GTiff

[Jon Saints]

You need to use gdal_warp instead of gdaltranslate. I
had the same problem for a while until the list helped
me.

To convert an hdf subset to geotiff with projection
information I use the command:

gdalwarp HDF_SUBSET_NAME_HERE OUT_FILE_NAME.tif

for example I run:
gdalinfo MYD09A1.A2004313.h21v10.004.2004324183345.hdf

and see:
Subdatasets:
SUBDATASET_1_NAME=HDF4_SDS:UNKNOWN:"MYD09A1.A2004313.h21v10.004.2004324183345.
hdf":0
  
I use this information to export the first hdf subset
to geotiff by the command:

gdalwarp
HDF4_SDS:UNKNOWN:"MYD09A1.A2004313.h21v10.004.2004324183345.
hdf":0 outfile_band1.tiff

I hope this helps
Jon


--- Brent Fraser <bfraser at geoanalytic.com> wrote:

> Thom,
> 
>   "+south" should do it.  Not too sure about "-19"
> as a zone number...  So
> try:
> 
> -t_srs "+proj=utm +zone=19 +south +datum=WGS84"
> 
>   If the orginal data is defined by GCPs and not a
> spatial reference system
> definition type (EPSG, proj, ...) gdalwarp/gdalinfo
> can translate into EPSG,
> then you will have to specifiy -t_srs option.
> 
> Brent
> 
> 
> ----- Original Message ----- 
> From: "Thom DeCarlo" <t.r.decarlo at larc.nasa.gov>
> To: "'Brent Fraser'" <bfraser at geoanalytic.com>;
> <gdal-dev at xserve.flids.com>
> Sent: Tuesday, July 12, 2005 2:50 PM
> Subject: RE: [Gdal-dev] projection lost when
> translating HDF to GTiff
> 
> 
> Hi Brent,
> Yes, it does show a coord sys, but it is defined by
> GCPs. I found an email
> in the archive that says I need to use gdalwarp to
> convert it into a
> geo-transform matrix-based system. I've tried doing
> that, but for some
> reason the output is not ending up in UTM. Instead,
> Imagine says it is
> Transverse Mercator. I've tried setting the target
> coord sys manually
> (-t_srs "+proj=utm +zone=-19 +datum=wgs84"), but I
> cannot figure out how to
> tell it that it is in the southern hemisphere. And I
> really don't think I
> should have to give it the target coord sys. The
> data is starting in UTM so
> it should stay in UTM.
> 
> --
> Thom DeCarlo
>
-------------------------------------------------------
>      Is it a bad sign if you spend the day wondering
> why there are no laws against what you do for a
> living?
>                                 - Dilbert
> 
> > -----Original Message-----
> > From: Brent Fraser
> > Sent: Tuesday, July 12, 2005 3:42 PM
> > To: Thom DeCarlo; gdal-dev at xserve.flids.com
> > Subject: Re: [Gdal-dev] projection lost when
> translating HDF to GTiff
> >
> > Thom,
> >
> >   Do you get a coord sys defined when you do a
> "gdalinfo" on the hdf file?
> >
> > Brent
> >
> >
> > ----- Original Message -----
> > From: "Thom DeCarlo" <t.r.decarlo at larc.nasa.gov>
> > To: <gdal-dev at xserve.flids.com>
> > Sent: Tuesday, July 12, 2005 11:52 AM
> > Subject: [Gdal-dev] projection lost when
> translating HDF to GTiff
> >
> >
> > Hi,
> > I gave up on compiling the HDF4 code myself and
> found that the binary
> > bundle
> > will work with a couple of tweaks.
> >
> > Anyway, I've got a bunch of ASTER DEM files that I
> need to convert to
> > geotiff and I'm losing the geographic projection
> info when I do the simple
> > "gdal_translate -of GTiff input.hdf output.tif"
> >
> > I looked at the online docs and didn't see
> anything special needed to do
> > this translate. Can someone tell me what I'm
> missing?
> >
> > Thanks,
> > Thom
> > --
> > Thom DeCarlo
> >
>
-------------------------------------------------------
> >           It is ok to celebrate diversity...
> > As long as you don't point out that people are
> different.
> >                                 - Colin Quinn
> >
> >
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> > Gdal-dev mailing list
> > Gdal-dev at xserve.flids.com
> > http://xserve.flids.com/mailman/listinfo/gdal-dev
> 
> 
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