20031111: IDV: parsing DODS grids from NOMADS

>From: Tom Whittaker <address@hidden>
>Organization: SSEC
>Keywords: 200310291448.h9TEmgOb028175 IDV NOMADS

Tom-

>When I put this URL in the IDV:
>
><http://nomads.ncdc.noaa.gov:9090/dods/NCDC_NOAAPort_GFS/200205/20020504/gfs-a
> vn_201_20020504_0000_fff>
>
>I get a nice set of 2D grids.  Only problem is, no 3D data...apparently the 
>vertical coordinate (dubbed "lev") is not a legitimate one for the IDV.  Is 
>this something I can correct somehow?  I tried adding "lev" as an alias for 
>PRESSURE, but that didn't seem to matter...
>
>In the DAS, lev is defined:
>
>lev {
>         String units "mb";
>         String long_name "altitude";
>         Float32 minimum 1000;
>         Float32 maximum 100;
>     }
>
>I figure that since this is a NOMDAS database that perhaps we should be able 
>to work with it....even if they do not adhere strictly to 'conventions'...?  I
>  
>looked at a couple of other datasets -- they all use 'lev' -- at least they're
>  
>consistent...

The problem is that "mb" is not a valid unit of altitude as per the 
COARDS convention that this file purports to adhere to.  Any unit 
specification must adhere to the standards of udunits as per the 
COARDS spec.   In udunits, "mb" is millibits, not millibars. We will
try to put in a fix on our end.  

I will also contact NCDC to inform them of this problem.

Don Murray
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