[GRASS-user] HDF-5 parse

GRASS GRASS user
1

Hello

I’m trying to import an HDF5 file and I’m having a few difficulties on “HOW to do this”. Is there any wiki/tutorial that explains how to import remote sensing data such as HDF5 files?

Thanks
Pedro

2

Pedro Roma:

I'm trying to import an HDF5 file and
I'm having a few difficulties on "HOW to do
this". Is there any wiki/tutorial that explains how to
import remote sensing data such as HDF5 files?

r.in.gdal, with the HDF5 driver:
  http://www.gdal.org/frmt_hdf5.html

see the "MODIS" wiki page for examples with HDF4, probably it is
not too different. (sorry if that page is a bit of a mess)

Hamish

3

Hi
Regarding this. using r.in.gdal it says that selected band do not exist.
About “HDF5 driver”, how can I use that driver using r.in.gdal command?

On Fri, Feb 12, 2010 at 4:26 AM, Hamish <hamish_b@yahoo.com> wrote:

Pedro Roma:

I’m trying to import an HDF5 file and
I’m having a few difficulties on “HOW to do
this”. Is there any wiki/tutorial that explains how to
import remote sensing data such as HDF5 files?

r.in.gdal, with the HDF5 driver:
http://www.gdal.org/frmt_hdf5.html

see the “MODIS” wiki page for examples with HDF4, probably it is
not too different. (sorry if that page is a bit of a mess)

Hamish

4

Hamish:

r.in.gdal, with the HDF5 driver

Pedro:

HiRegarding this. using r.in.gdal it
says that selected band do not exist.About "HDF5
driver", how can I use that driver using r.in.gdal command?

please post the file name, the results of gdalinfo, and the
exact r.in.gdal command line used.

see the "MODIS" wiki page for examples with HDF4,

    http://grass.osgeo.org/wiki/MODIS

Hamish

5

Hi

This is the command:
r.in.gdal input=/mnt/GIS/data/HDF5_GEO_200101011450 output=file_out

and the error is:

Projection of input dataset and current location appear to match
ERROR: Selected band (1) does not exist

Thank you
Pedro Roma

On Fri, Feb 12, 2010 at 12:30 PM, Hamish <hamish_b@yahoo.com> wrote:

Hamish:

r.in.gdal, with the HDF5 driver

Pedro:

HiRegarding this. using r.in.gdal it

says that selected band do not exist.About “HDF5
driver”, how can I use that driver using r.in.gdal command?

please post the file name, the results of gdalinfo, and the
exact r.in.gdal command line used.

see the “MODIS” wiki page for examples with HDF4,

http://grass.osgeo.org/wiki/MODIS

Hamish

6

On Fri, Feb 12, 2010 at 1:56 PM, Pedro Roma <pedroroma1982@gmail.com> wrote:

Hi
This is the command:
r.in.gdal input=/mnt/GIS/data/HDF5_GEO_200101011450 output=file_out

and the error is:
Projection of input dataset and current location appear to match
ERROR: Selected band (1) does not exist

As stated in
http://www.gdal.org/frmt_hdf5.html

you have to specify all the long funky name indicated in SUBDATASETXX.

Looks odd but it is the only way to the the data imported.

Markus

7

Ahhh ok I see
But it’s not possible to GRASS to identify each layer of HDF5 file?
Yes, indeed it looks odd and not very practical :(.

And regarding other products, example CEOS, it’s necessary to specify also CEOS:/file bla bla bla?

Thank you Markus

Pedro

On Fri, Feb 12, 2010 at 1:45 PM, Markus Neteler <neteler@osgeo.org> wrote:

On Fri, Feb 12, 2010 at 1:56 PM, Pedro Roma <pedroroma1982@gmail.com> wrote:

Hi
This is the command:
r.in.gdal input=/mnt/GIS/data/HDF5_GEO_200101011450 output=file_out

and the error is:
Projection of input dataset and current location appear to match
ERROR: Selected band (1) does not exist

As stated in

http://www.gdal.org/frmt_hdf5.html

you have to specify all the long funky name indicated in SUBDATASETXX.

Looks odd but it is the only way to the the data imported.

Markus

8

Hamish:

> please post the file name, the results of gdalinfo,
> and the exact r.in.gdal command line used.

Pedro wrote:

This is the command:r.in.gdal
input=/mnt/GIS/data/HDF5_GEO_200101011450 output=file_out

and the error is: Projection of
input dataset and current location appear to match
ERROR: Selected band (1) does not exist

ok, and what does gdalinfo say about available bands?

did you read this:
  http://www.gdal.org/frmt_hdf5.html

(the answer is in the second and third paragraphs.... you have
to tell it which band you want)

and this:

> see the "MODIS" wiki page for examples with HDF4,
> http://grass.osgeo.org/wiki/MODIS

??

(hint: "band" and "subdataset" are probably the same thing)

Hamish

9

Hamish wrote:

did you read this:
  http://www.gdal.org/frmt_hdf5.html
  

[snip]

(hint: "band" and "subdataset" are probably the same thing)
  

No. As it says a bit further down, after getting info for a specific subdataset: "You may use gdal_translate for reading image bands from this [selected sub-] dataset."

That's why r.in.gdal could not import all bands, because HDF (hierarchical data format) is something like a superdataset with subdatasets, each of these subdatasets may in turn hold several bands (usually only one band).

It is generally a good idea to first read the documentation in

http://www.gdal.org/formats_list.html

before trying to import/export raster maps via gdal

because there are 105 different formats, also CEOS, listed in

http://www.gdal.org/formats_list.html

where most of your questions are answered :wink:

Not many people know all the little peculiarities of all these formats by heart, most, also those providing answers, usually look up the details of a particular format in the documentation provided.

Markus M