Hi,
As part of upgrading our satellite data reception systems we are
planning to change how we store our remote sensing data. Currently an
in-house binary file format is used to store remote sensing data at
various levels of processing from raw swaths to composite gridded
datasets. Some of it comes from locally received HRPT streams, whilst
some of it comes from indirect sources (mostly in HDF-EOS formats).
We'd like to store all these internally using a common data format. In
some cases we'd like to be able to integrate with forecast model outputs
too.
Our current thinking tends towards standardising on netCDF (4) with
something like CF for metadata, though I am aware that CF is based on
the netCDF-3 data model and I don't see much discussion on how CF is
expected to evolve to embrace the netCDF-4 data model.
Reading up on netCDF-4 I see lots of references to the Common Data Model
(CDM) and the prototype implementation in NJ22. This seems to offer all
that CF does in the way of coordinate systems etc plus some higher level
datatypes specifically for things like swaths and grids (I guess
conceptually similar to the HDF-EOS types of the same name), though I
note that most of these are either not implemented or tagged
'experimental'. I also note that NJ22 includes a CF reader to extract
coordinate system data from CF files, but no other explicit references
to CF metadata that I can see.
And so to some specific questions:
- Is there a plan for extending CF to exploit the netCDF-4 data model?
- What advice do people have on the use of netCDF-4 with CF? (is the
use of features from the netCDF-4 data model allowed in a CF compliant
dataset? or should we stick to netCDF-4 *classic*?)
- what exactly is the relationship between CF and the CDM? Where they
cover the same functionality (eg coordinate systems) are they
consistent? (If not then what happens when netCDF-4.1 includes these
elements of the CDM as part of the netCDF standard?)
- Is there any intention to include the higher level data types from the
CDM as part of CF?
Sorry for the long post and list of questions; any insight would be most
gratefully received.
kind regards
Simon
--
Simon Wood
Scientific Programmer
Meteorology & Remote Sensing
National Institute of Water and Atmospheric Research (NIWA)
Wellington
New Zealand
Received on Wed Sep 13 2006 - 22:04:47 BST
