NOTICE: This version of the NSF Unidata web site (archive.unidata.ucar.edu) is no longer being updated.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.
>From: Robert Mullenax <address@hidden> >Organization: National Scientific Balloon Facility >Keywords: 199903052045.NAA17847 >I am trying to grid upper air files for use in producing u/a analyses in >Gempak. >I create a grid using oagrid with GRDAREA = 45;150;80;-100 and DTAAREA= > >The proram runs and creates a grid. When I use oabsnd to do an analysis >on the >grid I get the following error: > > >[GEMPLT -16] NIPBND - Invalid projection bounds. > [GR -7] Error defining grid navigation in GEMPLT. > [OABSND -9] No valid parameters have been entered > >Everything works fine if I don't define grdarea using the lat, lon, for >example if >I use grdarea=fai--, all is well. What have I done wrong? Thanks, and >sorry >for the barrage of questions. > >Robert Mullenax > > > Robert, Assumimg you have: DELTAN = DELTAX = DELTAY = for the above GAREA, oabsnd reports too few stations to calculate DELTAN at least for the IDD data I have. I can create the file with gdcfil, and I created a file for the above region as: GDOUTF = test.gem PROJ = ced GRDAREA = 45;150;80;-100 KXKY = 20;20 MAXGRD = 1000 CPYFIL = ANLYSS = GEMPAK-GDCFIL>r GDCFIL PARAMETERS: New grid file: test.gem Grid projection: CED Lower left corner: 45.00 150.00 Upper right corner: 80.00 -100.00 KX, KY: 20 20 X/Y grid spacing: 1.84 5.79 DELTAN = 8.592 EXTEND = 2; 2; 2; 2 Maximum number of grids that can be added to file 1000 Since oagrid would use a CED projection, that is what I specified in gdcfil. Running Oabsnd for 500mb hght, gives: SNFILE = $UPA/990304_upa.gem GDFILE = test.gem SNPARM = hght STNDEX = LEVELS = 500 VCOORD = pres DATTIM = 0000 DTAAREA = GUESS = GAMMA = .3 SEARCH = 50/EX NPASS = 2 GEMPAK-OABSND>r OABSND PARAMETERS: Output grid file: test.gem Number of x, y points: 20 20 Grid bnds: 45.00 150.00 80.00 -100.00 Grid xtnd: 2 2 2 2 Station spacing: 8.59 No first guess file is requested. Sounding file: $UPA/990304_upa.gem Data area: 40.00;-180.00;85.00;180.00 Level parameters: HGHT Levels: 500 Vertical coordinate: pres Station parameters: Time: 990304/0000 GAMMA: 0.30 SEARCH: 50.00 NPASS: 2 Data extrapolation may occur. Enter <cr> to accept parameters or type EXIT: Processing data at time 990304/0000 RMS values for pass 1 PARAMETER: HGHT LEVEL: 500 RMS: 48.29 #STN: 31 RMS values for pass 2 PARAMETER: HGHT LEVEL: 500 RMS: 26.87 #STN: 31 So, there is nothing intrinsically wrong with the grdarea you want to use. I think the problem exists with the EXTEND area. Depending on the KXKY that OAGRID ends up suggesting, it could be wrapping the north pole- which is very bad in a CED projection. Have you tried setting EXTEND = 0;0;0;0? can you send me the output from oagrid so I can see what the suggested station spaceing for the grid is, and if the extended area will wrap over the pole? Steve Chiswell