[Gdal-dev] convert HDF ASTER to geotiff

[Jon Saints]

Ok, I have narrowed the problem.

Yes, I agree that ASTER's come with ground control
points, however, when using gdal_translate it seems
that the utility doesnt apply the ground points
correctly.

My observation is this: In the raw aster image the
corners (ul and lr) of the raw image data are not the
"corners" of the data. Along both edges of the actual
data there are no data values hold space as padding. 
The actual image data is a slanted trazezoid padded on
both sides with no data values within the rectangle
that is the raw aster image. gdal_translate can apply
the GCP points to the raw image, but does so
incorrectly. It applies the ul and lr values to the no
data padding of the raw image, rather than applying
the point to the actual corner where the actual data
begins.  

I hope this makes some sense. I found it difficult to
explain without drawing pictures.  

Is there any workaround for this?

Thanks
Jon


--- Kenneth Melero <kmelero at sanz.com> wrote:
> 
> Andrey,
> 
> Can you provide an example of this?
> 
> Thanks!
> -Ken
> 
> -----Original Message-----
> From: gdal-dev-bounces at xserve.flids.com
> [mailto:gdal-dev-bounces at xserve.flids.com] On Behalf
> Of Andrey Kiselev
> Sent: Saturday, April 30, 2005 2:42 AM
> To: gdal-dev at remotesensing.org
> Subject: Re: [Gdal-dev] convert HDF ASTER to geotiff
> 
> 
> On Fri, Apr 29, 2005 at 01:18:15PM -0700, Jon Saints
> wrote:
> > Hi, I am new to GDAL. I have had some success
> converting hdf to tif 
> > using gdal_translate.
> > 
> > i have not been able to apply a coorsys to the new
> tif image.  has 
> > anyone any expirience with this sort of thing?
> 
> ASTER scenes are georeferenced with GCP points, that
> means you should use
> gdalwarp to transform the scene in desirable
> projection and extent. And you
> definitely need the latest CVS snapshot of GDAL
> sources where the proper
> functionality has been implemented.
> 
> Regards,
> Andrey
> 
> -- 
> Andrey V. Kiselev
> Home phone:  +7 812 5970603  ICQ# 26871517
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