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[Datastream #ZAM-591769]: FNEXRAD Feed for National Radar Mosaics

Hi Greg,

re:
> Thanks for your help. See comments and questions below:

> On 
> http://www.unidata.ucar.edu/software/ldm/ldm-current/basics/feedtypes/fnexrad.html,
> there are 2 links that are broken, one called "Floater site selection
> page" and one called: "How to access NEXRAD adata via the LDM". On
> http://www.unidata.ucar.edu/software/gempak/examples/gdradr/ , the link
> labeled "NEXRAD products" at the top of the page is broken as well as
> the link titled "GDRADR" and "CPYFIL" under the section title Running
> GDRADR on this same web page.

Thanks for reporting these; we will attend to them.

re: You can pretty much glean this information from a 'notifyme' listing

> This is where I get confused.

I overstated being able to glean which product is what. Chiz told me that the
1 km N0R composite had to be stored in a GRIB2 message since GRIB1 was not able 
to store
a product that large.  Given that info, it is now not clear to me what the 
following
represents:

radar_mosaic_national !grib/unidata/UPC_1/#255/200802271818/F000/N0R/sfc!

It is definitely a N0R (base reflectivity) composite in GRIB1 format, but I 
don't know
what its resolution is.  Given its size relative to the 1 km N0R composite that 
is in GRIB2
format, I would guess that it is a 6 km composite.

> So if I want a 1km National Mosaic of base
> reflectivity in grib format, do I want rad/NEXRCOMP/1km/n0r_YYYYMMDD_HHmm
> or radar_mosaic_national?

You want the radar_mosaic_nathr for the 1 km N0R composite in GRIB2 format (not 
GRIB).
The products that include NEXRCOMP in their id are images in GINI format.  GRIB 
(not
GRIB2) is used for lower resolution products.

> And what is radar_mosaic_nathr - hourly 6km base reflectivity?

No, it is the 1 km national (nat) Hi Res (hr) N0R composite.  The tipoff for its
resolution is the size of the GRIB2 message which is routinely > 2.5 MB. 

Also, one of the products in GRIB format is a composite of Echo Tops (NET):

radar_mosaic_national !grib/unidata/UPC_1/#255/200802272349/F000/NET/sfc!

Sorry for the confusion.  I will dig through the GEMPAK website to see if Chiz 
documented
these products somewhere.  The comments in the pqact.conf file of GEMPAK actions
are not definitive enough to figure out the resolution for the 
radar_mosaic_national
product, but they are for the 1km composite:

#
# National radar composite generated by GDRADR for IDD
FNEXRAD ^radar_mosaic_national
        PIPE    decoders/dcgrib2 -v 4 -d data/gempak/logs/dcgrib2_radar.log
        -e GEMTBL=/home/gempak/NAWIPS/gempak/tables
        data/gempak/radar/YYYYMMDD_radr.gem
#
# 1km National radar composite generated by GDRADR for IDD
FNEXRAD ^radar_mosaic_nathr
        PIPE    -close  decoders/dcgrib2 -v 1 -d 
data/gempak/logs/dcgrib2_radarhr.log
        -e GEMTBL=/home/gempak/NAWIPS/gempak/tables
        data/gempak/radar/YYYYMMDD_rad1.gem

Cheers,

Tom
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Ticket Details
===================
Ticket ID: ZAM-591769
Department: Support Datastream
Priority: Normal
Status: Closed