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20040830: thoughts about upgrading

>From: "Frank Colby" <address@hidden>
>Organization: UMass Lowell
>Keywords: 200408301851.i7UIp18E026405

>Dear Unidata Support,
>
>We would like to start getting satellite and radar data through our ldm,
>and displaying it in GARP.  I perused the portal site, and am confused
>as to what would be useful here.
>
>1)  If we get McIdas satellite data, can we display it in GARP, and
>overlay it if we want to?

Frank,

GEMPAK (and GARP) can display McIDAS Format AREA files from the UNIWISC feed,
as well as GINI (NCEP) format from the NIMAGE feed. GEMPAK can overlay
non-image data onto imagery (eg obs, contours, vectors etc), but cannot
map imagery onto imagery.

>
>2)  Is the volume of NIDS data smaller than the Level II data from OU?
>Again, can we overlay the NIDS data onto other images?

Yes. You can view the volume of data feeds from
http://my.unidata.ucar.edu/content/software/idd/rtstats

The NIDS volume time series for example is peaking around 200 MB per hour 
currently:
http://my.unidata.ucar.edu/cgi-bin/rtstats/iddstats_vol_nc?NNEXRAD+thelma.ucar.edu

Whereas the Level II data is 1.2GB:
http://my.unidata.ucar.edu/cgi-bin/rtstats/iddstats_vol_nc?CRAFT+thelma.ucar.edu


The LEVEL III (NIDS) products are typically on the order of 10 to 30K
each (times 11-15 products per radar site (153 total)). Not all
radar sites will be part of the Level II data (eg some FAA and DOD
WSR-88D's are not prt of the Level II data feed for the NWS).


>
>3)  What tools are available to provide access to text data?  

NWX is the GEMPAK program used to display test data.

http://my.unidata.ucar.edu/content/software/gempak/tutorial/nwx.html
http://my.unidata.ucar.edu/content/software/gempak/tutorial/nwx2.html
http://my.unidata.ucar.edu/content/software/gempak/tutorial/nwx3.html 
etc.


>I didn't
>see anything about WXP, which I thought was one way to handle this, but
>maybe that's not available from Unidata?  

WXP is owned by Unisys, wxp.unisys.com.

>Right now, we just put all the
>text data into files, ship them to our old VAX cluster, and use our old
>home-grown decoders to break this up into various files.  We are ready
>to retire the vaxes, and need an alternative to list hourly data, mos,
>fous, etc.  Do most sites just use scripts and grep to handle this?  We
>set up indexed files for MOS, FOUS and hourlies, which provide quick
>access.  These could be moved to a new machine, but if there is
>something already set up for this, it might be simpler.

The NWX interface is built to use flat files stored by the LDM.
I provide pqact entries for storing the data from the LDM.
We have piced together low cost PCs that can handle the data streams
for under $1000. A stock Pentium P4 box is generally fine, with 
a raid file system for disk space. dual processor systems are 
probably better if you need to do other tasks on the box than
just LDM service (eg generate local products).

Steve Chiswell



>
>Thanks!
>
>Frank Colby
>UMass Lowell
>
>
>
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