This archive contains answers to questions sent to Unidata support through mid-2025. Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated. For the most up-to-date information on the use of NSF Unidata software and data services, please consult the Software Documentation first.
> Yuan, > > You image looks great and I wish I could replicate it! Where did you change > the standard longitude? > > David There is global attribute in this file: :STAND_LON = -90.0f; // float Change this to -80 will make it works. Yuan > > On Sep 23, 2014, at 2:46 PM, Unidata IDV Support <address@hidden> wrote: > > >>> Yuan, > >>> > >>> For whatever reason, what you have detailed below does not work for me. > >>> I would like both the 2D and 3D fields to be correctly displayed in the > >>> stereographic projection in IDV. I also don’t see two map projections > >>> defined in the netCDF file (in the field selector tab I right-clicked on > >>> the file and read the metadata and can only find Polar Stereographic). > >>> Can you clarify where you see this? When I load in any variable (2-D or > >>> 3-D) and and click on use grid projection I still see that the coastline > >>> does not match up with the background map as in the image I sent > >>> previously. Before loading in the data I did unselect the > >>> auto-projection feature. I do see that the projection is set to > >>> stereographic but the two still don’t align. Would you be able to send > >>> me an image of he model terrain on top of the background map to see how > >>> it differs from my own? Also, I am using IDV 4.1 if that makes any > >>> difference. > >>> > >>> David > >>> > >> > >> David, > >> I see the problem. > >> For historical reason, the nc output from the WRF has never been CF > >> compliance. The netCDF group developers have to do something special to > >> make it look like good nc file. In your case, > >> the stereographic projection is being applied to the 3D variable but not > >> 2D and this is likely why you see the coast lines not match with your data. > >> > >> I will check if there is anything can be done here to make it works. > >> > >> > >> Yuan > > > > David, > > The problem is your dataset. The standard longitude in this data > > file is still -90, not -125 as you claimed in your first email. If I > > changed this value to -80, I can get > > the corrected location, see the attached. > > > > > > Yuan > >>> > >>> On Sep 23, 2014, at 12:27 PM, Unidata IDV Support <address@hidden> wrote: > >>> > >>>>> IDV Support, > >>>>> > >>>>> I have uploaded the WRF file. In addition, I have attached a .gif > >>>>> image here showing how the coast lines don’t match. > >>>>> > >>>>> Thanks for your help, > >>>>> > >>>>> David Siuta > >>>> > >>>> Hi David, > >>>> There is nothing wrong with the IDV or your dataset. Inside this nc > >>>> dataset, there are two set projections, polar stereographic and lat/lon. > >>>> When you load a 2D variable, it is using lat/lon projection. > >>>> If you want to see the same projection for 3D variable, you can turn off > >>>> the auto set projection under Projections > Auto-set Projection before > >>>> creating the display. If you want to switch between these two > >>>> projections, right click on the legend of one of display and select: > >>>> View > Use Grid Projection. The IDV will do the work of converting the > >>>> projection automatically for you. > >>>> > >>>> > >>>> Yuan > >>>>> > >>>>> address@hidden > >>>>> > >>>>> On Sep 23, 2014, at 10:20 AM, Unidata IDV Support <address@hidden> > >>>>> wrote: > >>>>> > >>>>>> David, > >>>>>> > >>>>>> Sorry for the delayed response. > >>>>>> > >>>>>> Please upload your WRF sample data here: > >>>>>> > >>>>>> http://motherlode.ucar.edu/repository/alias/idvupload > >>>>>> > >>>>>> and let us know when it has been uploaded. > >>>>>> > >>>>>> Best, > >>>>>> > >>>>>> Unidata IDV Support > >>>>>> > >>>>>>> IDV support, > >>>>>>> > >>>>>>> I have done some research in to my problem (Ticket BRK-528772) and > >>>>>>> found > >>>>>>> that the standard longitude is not the problem. It is actually the > >>>>>>> map > >>>>>>> projection used by WRF that doesn’t work well with IDV. Any WRF runs > >>>>>>> I have done using the polar stereographic map projection do not match > >>>>>>> the background map supplied in IDV when I try to view the output in > >>>>>>> IDV > >>>>>>> (as well as the latitude and longitude of the WRF grid does not match > >>>>>>> the background map). To test this out I changed the WRF projection to > >>>>>>> Lambert Conformal Conic and reran WRF and no matter what the standard > >>>>>>> longitude was, the WRF grid was able to perfectly match the IDV > >>>>>>> background map. Even though switching WRF to the Lambert projection > >>>>>>> has > >>>>>>> solved this problem temporarily, I have a lot of output in the Polar > >>>>>>> Stereographic projection and would like to be able to use IDV to view > >>>>>>> some of the output. Do you have any ideas on how to fix this? > >>>>>>> > >>>>>>> Thanks, > >>>>>>> > >>>>>>> David Siuta > >>>>>>> address@hidden > >>>>>>> > >>>>>>> Weather Forecast Research Team > >>>>>>> University of British Columbia > >>>>>>> Vancouver, BC Canada > >>>>>>> > >>>>>> > >>>>>> > >>>>>> Ticket Details > >>>>>> =================== > >>>>>> Ticket ID: YZK-803896 > >>>>>> Department: Support IDV > >>>>>> Priority: Normal > >>>>>> Status: Closed > >>>>> > >>>>> > >>>>> > >>>> > >>>> Ticket Details > >>>> =================== > >>>> Ticket ID: YZK-803896 > >>>> Department: Support IDV > >>>> Priority: Normal > >>>> Status: Closed > >>> > >>> > >> > > > > > > Ticket Details > > =================== > > Ticket ID: YZK-803896 > > Department: Support IDV > > Priority: Normal > > Status: Closed<terrain.gif> > > Ticket Details =================== Ticket ID: YZK-803896 Department: Support IDV Priority: Normal Status: Closed