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Re: 20010120: radar_national_mosaic?

Neil,

gpmap can display "NIDS" NEXRAD radar images using RADFIL and proj=rad.
Satellite or other images in "AREA" or "GINI" formats can be displayed with
SATFIL and proj=sat.

But, the mosaic product is not a NEXRAD image. Its a grid file, just like
a model output or oabsfc objective analysis, etc.
You can display the grid in any projection, and overlay on images too.

The program GDRADR reads the NEXRAD images (each of which has
a unique projection centered on the radar location), and creates
a grid projection that is used to sample each radar. The result
is a gempak grid file. In the data stream, I use the GDGRIB program
to create a GRIB message from the GEMPAK grid so that users of
other software packages can decode the GRIB to their software too.
The grib decoder for GEMPAK just decodes the product back to
a GEMPAK grid. You can also use the grid in computations as I showed on the
web page combining temperature grids to create a precipitation type product.

Hope that clears up the confusion.

Steve Chiswell
Unidata User SUpport



On Fri, 25 Jan 2002, Neil R. Smith wrote:

> Thanks Steve. Guess we'll just decode to gempak format. But
> do I read you correctly as saying one should be able to
> display from the raw file as an image using RADFIL and/or
> SATFIL in a display program such as gpmap? -Neil
>
> Steve Chiswell wrote:
> >
> > Niel,
> >
> > The radar mosaic is in grib format. So, you can decode it
> > with dcgrib2 as Pete mentioned. And, display the grid
> > with gdplot2 just as you would decoded model data.
> >
> > Your previous message showed you were trying to display it
> > as an image, which is what the RADFIL and SATFIL parameters
> > in display programs are for. Instead, just use the decoded gempak
> > grid file in any program as GDFILE. The paramter (GFUNC)
> > will be N0R on GLEVEL=0, and GVCORD=NONE.
> >
> > Steve Chiswell
> >
> > On Wed, 16 Jan 2002, Neil R. Smith wrote:
> >
> > > Thanks Pete. I too saw that email and pursued the references.
> > > I saw the pqact decoding involvement and was hoping that if
> > > the original ingested file is a standard radar grib file I
> > > could use our existing web gif generating scripts that were
> > > built to use the WSI "MASTER" product - a N.Amer. radar
> > > composite. Or at least that's what I assume "MASTER" is.
> > >
> > > If I can't get that dog to hunt I will, with your permission,
> > > use your scripts with appropriate acknowledgement.
> > >
> > > Thanks again, -Neil
> > > --
> > > Neil R. Smith, Comp. Sys. Mngr.               address@hidden
> > > Dept. Atmospheric Sci., Texas A&M Univ.       979/845-6272 
> > > FAX:979/862-4466
> > >
>
> --
> Neil R. Smith, Comp. Sys. Mngr.               address@hidden
> Dept. Atmospheric Sci., Texas A&M Univ.       979/845-6272 FAX:979/862-4466
>