[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[IDV #ERN-936668]: Adapting IDV to KNMI data

Hi Ernst: sounds very ambitious! Everything sounds doable, with one caveat: the 
opendap server has not yet been updated to deal with some of the latest  
features in CDM 4.0, such as Groups. However, Im not sure if you need that yet. 
If everything goes well, opendap protocol will be extended, and we will get 
that feature into 4.1 release. We also are considering options of IDS reading 
from TDS  if that doesnt happen soon.

If you can make example files available, I can probably give you some real 
advice. Perhaps choose one (or maybe two) things to work on at a time. 
otherwise it may be hard to keep track.

> Hi,
> 
> 
> 
> As you may know we are trying to run IDV at KNMI for evaluation
> purposes. What I was hoping was to make some adaptations to the
> NetCDF-java 4.0 library to be able to get to our local data into the IDV
> using TDS as data server.
> 
> 
> 
> Data I would like to show is:
> 
> *     ECMWF GRIB data
> *     HIRLAM GRIB data
> *     Radar HDF5 image data (projected bitmap's of precipitation).
> *     Satellite HDF image data (projected bitmap's of sat. products).
> 
> 
> 
> Later perhaps:
> 
> *     KNMI HDF5 format of lightning discharges (locations of
> discharges from an HDF5 table)
> *     KNMI HDF5 format of wind profiles from radar
> *     KNMI HDF5 format of radial data
> *     Observational data
> 
> 
> 
> 
> 
> So my plan is:
> 
> 1.    Create grib table for KNMI HIRLAM
> 2.    Put ECMWF and HIRLAM data into TDS
> 3.    Make a KNMIHDF5ImageConvention class in the NetCDF-java library,
> that reads a KNMI HDF5 file and generates a grid, adding some variables
> for coordinate systems etc and moving the interesting variables to the
> root group.
> 4.    Create a class for KNMI radar's polar stereographic projection
> in the NetCDF-java library, which has a non-spherical earth.
> 5.    Put satellite and  radar products in TDS.
> 6.    View gribs and HDF5 images in IDV.
> 
> 
> 
> These 6 steps should at least make it possible to read in KNMI grib
> files (at standard pressure levels) and satellite and radar products.
> 
> 
> 
> I believe I managed steps 1 and 2 , so model data are now visible (as
> long as there are no model levels involved). I might need to implement a
> vertical coordinate model for HIRLAM.
> 
> 
> 
> I made a lot of progress on step 3 and step 4. I can visualise a KNMI
> HDF5 file from the file system as an image file in IDV. The time stamp
> is allright, but in animations the images don't seem to have an end
> time, so they don't animate correctly.
> 
> 
> 
> I spent a lot of time with step 5. I was hoping that with the adapted
> NetCDF-java library TDS would also handle these "enhanced" NetCDF files
> derived from HDF5, but that does not seem to work. I might be trying the
> wrong thing here though.
> 
> 
> 
> I guess my main question is: could this setup work?
> 
> 
> 
> When I know that I will have some more questions for you about "smaller"
> problems/inclarities.
> 
> 
> 
> Regards Ernst de Vreede
> 
> KNMI
> 
> 
> 
> 
> 


Ticket Details
===================
Ticket ID: ERN-936668
Department: Support netCDF Java
Priority: Normal
Status: Open