NOTICE: This version of the NSF Unidata web site (archive.unidata.ucar.edu) is no longer being updated.
Current content can be found at unidata.ucar.edu.

To learn about what's going on, see About the Archive Site.

Re: Problems with polar-stereographic 3d files

Hi Don,

thanks a lot. With the new nightly version I'm able to get nice vertical cross-sections. The alps where correctly positioned and the values seems okay.

The automatical selection of the projection still doesn't work with the 3d fields, and the grid-cells are placed according to their lat lon points in the default (mercator?) grid instead of in the polar-stereographic grid. I have to manually select the projection of one of the 2d fields to get my projection.

Best regards,

Heiko

Don Murray wrote:
Hi Heiko-

I think I solved this problem and the fix will be in tomorrow's
nightly build (after 4/17 8UTC):

http://www.unidata.ucar.edu/software/idv/release/nightly

If you could test it out, I'd appreciate it.

Don

Don Murray wrote:
Your post is timely as I'm looking into this issue today.

Heiko Klein wrote:
I've been using IDV for a while to display 2d fields in a polar-stereographic grid (CF convention). Now I tried to see a 3d field with sigma levels. Though the projection parameters are the same, when looking at a plan-view of a single layer, idv reverts to its default projection instead of my polar-stereographic view.

The problem is that for the IDV to plot the 3D sigma levels
in the map display, it needs to have a relationship between sigma
and altitude.  The only way we have to do this is transform the
grid to altitude values and in the process the projection information
gets lost.

When I try to make a vertical cross-section, I cannot see any data. The altitude display shows always a 'Distance along transect' scale from -0.4km .. 0.4 km and no altitude scale at all (autoscale y axis). The location coordinates of the cross-section are updated correctly.

This was reported last week by another user. It uncovered
a bug in the underlying netCDF Java library which has been fixed, so
now I have to see what's happening on the IDV side.

This looks all like a problem with my projection in the 3d fields, but I couldn't find any mistakes. Maybe somebody else can look at it? The file can be downloaded at ftp://ftp.met.no/pub/emep/heikok/Base_hour.nc

I hope to have this figured out today, but since it involves a radical
change in how we deal with the sigma grids, it might have other reprecussions.

Don
*************************************************************
Don Murray                               UCAR Unidata Program
dmurray@xxxxxxxxxxxxxxxx                        P.O. Box 3000
(303) 497-8628                              Boulder, CO 80307
http://www.unidata.ucar.edu/staff/donm
*************************************************************




  • 2007 messages navigation, sorted by:
    1. Thread
    2. Subject
    3. Author
    4. Date
    5. ↑ Table Of Contents
  • Search the idvusers archives: