# satellite metadata **URL:** \ **Category:** Hdf-forum archives\ **Created:** [September 17, 2010, 12:52am UTC](https://forum.hdfgroup.org/t/satellite-metadata/1903 "2010-09-17T00:52:01Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Rudi\_Gens](https://forum.hdfgroup.org/letter_avatar_proxy/v4/letter/r/73ab20/32.png) [@Rudi\_Gens](https://forum.hdfgroup.org/u/Rudi_Gens)\ **Post date:** [September 17, 2010, 12:52am UTC](https://forum.hdfgroup.org/t/satellite-metadata/1903/1 "2010-09-17T00:52:01Z")
I am developing a prototype to save SAR data at various levels and processing stages in HDF5 format. In order to properly describe this data (e.g. the side looking geometry or orbit information in form of state vectors), I would need to generate a larger number of attributes that would benefit from a structure in groups. The majority of the attributes would apply to all data sets. Sometimes, you will have several bands in a data set with a very limited number of attributes specific to the band (e.g. its polarization). Is there a standard way of going about saving this type of metadata structure in HDF5? Another somewhat related question is how to handle map projection information for geocoded data. Any best practice for that? > **···** > > -- > View this message in context: [http://hdf-forum.184993.n3.nabble.com/satellite-metadata-tp1515627p1515627.html](http://hdf-forum.184993.n3.nabble.com/satellite-metadata-tp1515627p1515627.html) > Sent from the hdf-forum mailing list archive at [Nabble.com](http://Nabble.com). ---
**Author:** ![r.m.van.hees](https://forum.hdfgroup.org/letter_avatar_proxy/v4/letter/r/cdc98d/32.png) [@r.m.van.hees](https://forum.hdfgroup.org/u/r.m.van.hees)\ **Post date:** [September 17, 2010, 6:39am UTC](https://forum.hdfgroup.org/t/satellite-metadata/1903/2 "2010-09-17T06:39:34Z")
Please, take a look at the CF metadata conventions: [http://cf-pcmdi.llnl.gov/](http://cf-pcmdi.llnl.gov/) It assumes that you use netCDF, but using netCDF-4 you can write well structured HDF5 files, or you can follow the conventions using standard HDF5 functions. I have participated in a small project called ADAGUC where we tried to address also the meta data for remote sensing datasets: [http://adaguc.knmi.nl/](http://adaguc.knmi.nl/) Good luck, Richard > **···** > > On 09/17/2010 02:52 AM, rudigens wrote: > > > I am developing a prototype to save SAR data at various levels and processing > > stages in HDF5 format. > > > > In order to properly describe this data (e.g. the side looking geometry or > > orbit information in form of state vectors), I would need to generate a > > larger number of attributes that would benefit from a structure in groups. > > The majority of the attributes would apply to all data sets. Sometimes, you > > will have several bands in a data set with a very limited number of > > attributes specific to the band (e.g. its polarization). Is there a standard > > way of going about saving this type of metadata structure in HDF5? > > > > Another somewhat related question is how to handle map projection > > information for geocoded data. Any best practice for that? ---
**Author:** ![Rudi\_Gens](https://forum.hdfgroup.org/letter_avatar_proxy/v4/letter/r/73ab20/32.png) [@Rudi\_Gens](https://forum.hdfgroup.org/u/Rudi_Gens)\ **Post date:** [September 17, 2010, 5:28pm UTC](https://forum.hdfgroup.org/t/satellite-metadata/1903/3 "2010-09-17T17:28:25Z")
Richard, Richard van Hees wrote: > Please, take a look at the CF metadata conventions: > [http://cf-pcmdi.llnl.gov/](http://cf-pcmdi.llnl.gov/) > It assumes that you use netCDF, but using netCDF-4 you can write well > structured HDF5 files, or you can follow the conventions using standard > HDF5 functions. > I have participated in a small project called ADAGUC where we tried to > address also the meta data for remote sensing datasets: > [http://adaguc.knmi.nl/](http://adaguc.knmi.nl/) The other data format addressed in the prototype is actually netCDF. I have followed the CF conventions and I am working with some netCDF folks to check the correctness of the implementation. The "extra" metadata beyond the CF convention is one of the remaining questions for the netCDF prototype as well. There are a number of ways to group them. I am searching for a solution that looks somewhat intuitive to the netCDF/HDF5 user communities. Some of the "common practice" with the netCDF format was a little puzzling for me. The projection is usually defined according to the CF convention with individual projection parameters, with the ArcGIS projection file type string as well as the proj4 definition of the projection. That sounds a little overkill to me but then there are two additional layers for latitude/longitude per pixel added on top of that. That got me into the use of compression and netCDF-4 with HDF5 in the background. Otherwise the file sizes cross the GB limit big time with images in the order of 10000x10000 pixels. I was hoping that the HDF5 world has a little simpler convention. Thanks for the link to ADAGUC. Very nice use case. Cheers, Rudi > **···** > > -- > View this message in context: [http://hdf-forum.184993.n3.nabble.com/satellite-metadata-tp1515627p1517583.html](http://hdf-forum.184993.n3.nabble.com/satellite-metadata-tp1515627p1517583.html) > Sent from the hdf-forum mailing list archive at Nabble.com. ---
**Author:** ![Martin\_Raspaud](https://forum.hdfgroup.org/letter_avatar_proxy/v4/letter/m/b9bd4f/32.png) [@Martin\_Raspaud](https://forum.hdfgroup.org/u/Martin_Raspaud)\ **Post date:** [October 1, 2010, 8:00am UTC](https://forum.hdfgroup.org/t/satellite-metadata/1903/4 "2010-10-01T08:00:20Z")
Richard van Hees skrev: > **···** > > > On 09/17/2010 02:52 AM, rudigens wrote: > > > > > I am developing a prototype to save SAR data at various levels and > > > processing > > > stages in HDF5 format. > > > > > > In order to properly describe this data (e.g. the side looking > > > geometry or > > > orbit information in form of state vectors), I would need to generate a > > > larger number of attributes that would benefit from a structure in > > > groups. > > > The majority of the attributes would apply to all data sets. > > > Sometimes, you > > > will have several bands in a data set with a very limited number of > > > attributes specific to the band (e.g. its polarization). Is there a > > > standard > > > way of going about saving this type of metadata structure in HDF5? > > > > > > Another somewhat related question is how to handle map projection > > > information for geocoded data. Any best practice for that? > > > > Please, take a look at the CF metadata conventions: > > [http://cf-pcmdi.llnl.gov/](http://cf-pcmdi.llnl.gov/) > > It assumes that you use netCDF, but using netCDF-4 you can write well > > structured HDF5 files, or you can follow the conventions using standard > > HDF5 functions. > > I have participated in a small project called ADAGUC where we tried to > > address also the meta data for remote sensing datasets: > > [http://adaguc.knmi.nl/](http://adaguc.knmi.nl/) > > > > Good luck, Richard > > The cf conventions are being actively developed at the moment for satellite > data. Take a look here: > [http://mailman.unidata.ucar.edu/mailman/listinfo/cf-satellite](http://mailman.unidata.ucar.edu/mailman/listinfo/cf-satellite) > > Best regards, > Martin ---
**Author:** ![r.m.van.hees](https://forum.hdfgroup.org/letter_avatar_proxy/v4/letter/r/cdc98d/32.png) [@r.m.van.hees](https://forum.hdfgroup.org/u/r.m.van.hees)\ **Post date:** [October 1, 2010, 8:48am UTC](https://forum.hdfgroup.org/t/satellite-metadata/1903/5 "2010-10-01T08:48:23Z")
Thanks, I was not aware of its existence. I will definitely subscribe to this list. Greetings, Richard > **···** > > On 10/01/10 10:00, Martin Raspaud wrote: > > > -----BEGIN PGP SIGNED MESSAGE----- > > Hash: SHA1 > > > > Richard van Hees skrev: > > > > >   On 09/17/2010 02:52 AM, rudigens wrote: > > > > > > > I am developing a prototype to save SAR data at various levels and > > > > processing > > > > stages in HDF5 format. > > > > > > > > In order to properly describe this data (e.g. the side looking > > > > geometry or > > > > orbit information in form of state vectors), I would need to generate a > > > > larger number of attributes that would benefit from a structure in > > > > groups. > > > > The majority of the attributes would apply to all data sets. > > > > Sometimes, you > > > > will have several bands in a data set with a very limited number of > > > > attributes specific to the band (e.g. its polarization). Is there a > > > > standard > > > > way of going about saving this type of metadata structure in HDF5? > > > > > > > > Another somewhat related question is how to handle map projection > > > > information for geocoded data. Any best practice for that? > > > > > > Please, take a look at the CF metadata conventions: > > > [http://cf-pcmdi.llnl.gov/](http://cf-pcmdi.llnl.gov/) > > > It assumes that you use netCDF, but using netCDF-4 you can write well > > > structured HDF5 files, or you can follow the conventions using standard > > > HDF5 functions. > > > I have participated in a small project called ADAGUC where we tried to > > > address also the meta data for remote sensing datasets: > > > [http://adaguc.knmi.nl/](http://adaguc.knmi.nl/) > > > > > > Good luck, Richard > > > > The cf conventions are being actively developed at the moment for satellite > > data. Take a look here: > > [http://mailman.unidata.ucar.edu/mailman/listinfo/cf-satellite](http://mailman.unidata.ucar.edu/mailman/listinfo/cf-satellite) > > > > Best regards, > > Martin > > -----BEGIN PGP SIGNATURE----- > > Version: GnuPG v1.4.9 (GNU/Linux) > > Comment: Using GnuPG with Fedora - [http://enigmail.mozdev.org/](http://enigmail.mozdev.org/) > > > > iQEcBAEBAgAGBQJMpZUTAAoJEBdvyODiyJI4T3QH/jvRy+uB0BRJuxK+r+P1NOkP > > JjjSWWaPl1OTJTrbtPhgw0VIszyfaFgi0c9+xjltai2N5W5xJXTIRITFOZccw+RQ > > F9QQebmjGwKdhm5aBx9MdaIR6FiLVsYQB0fvoPepeoB/TKEZoOziRUM2rqNZbOXa > > /vDFYqlG27Leqf2i/mlU57t3Pl+V3jSW0WOoQuCkAMGWk74ujfiIuo07wWtivI5b > > d7oH/GRNFMl74BSbyrdB9MRRVtO28fmerRM5/mUCfE5FzSqnRf9rCWbxpxscik7H > > AnN1hLFdjlRfMCwDsPWH9/dDFo+9Djp7ycv2HDtHc4ofzPJDkEpPhAYLPQLogLE= > > =zcIb > > -----END PGP SIGNATURE----- > > > > \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ > > Hdf-forum is for HDF software users discussion. > > Hdf-forum@hdfgroup.org > > [http://mail.hdfgroup.org/mailman/listinfo/hdf-forum\_hdfgroup.org](http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org)