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Re: 20030610: top level IDD relays needed for NEXRAD Level II data

Hi Tom, et al,

Part of the deal of working with these sites using the Level II data, is to utilize sites on Internet2. That's why Guy Almes has been so interested in this project and trying to help. I just checked and sjsu doesn't seem to be listed among the Internet2 sites. Have they recently become a member? Also, the same holds true for Plymouth State, but perhaps they are on it now too.

Just an observation. It looks like we will probably have plenty of sites anyway, right?


--On Wednesday, June 11, 2003 10:47 AM -0700 Mike Voss <address@hidden> wrote:

Tom et al,

San Jose State University is in general willing to be a relay for the
NEXRAD Level II Data. Now, that being said the potential volume of data
is a bit of a concern, I'm guessing for others as well. The current
volume of 140 MB per hour is certainly manageable. However, if we take
Tom's estimation that the data "may" increase by 4 times and then by 8
again we have 140 X 4 X 8 = 4480 MB of data per hour (4.5 GB). This is
more than double CONDUIT and comes to ( X 8 / 3600) nearly 10 mbps, quite
a load, which would require a massive queue and significant bandwidth. I
still think this is possible, but we may need to require a practice of
requesting only a subset of the feed, especially for the downstream


PS, the increase in performance of the LDM since the last major revision
has been amazing, flawless..thanks again!!

PPS, Let's send the 1KM visible statellite imagery through the IDD. At
one time I think it was considered to large, but it's really a fraction
of CONDUIT and highly desired/usefull.

At 05:58 PM 6/10/2003 -0600, Unidata Support wrote:
From: Unidata User Support <address@hidden>
Organization: Unidata Program Center/UCAR
Keywords:  IDD NEXRAD Level II CRAFT


As you may know, the NWS will soon begin collecting and distributing
NEXRAD Level II using the Unidata LDM-6.  The NWS effort is the
outgrowth of the CRAFT experiment that has and continues to be run by
the University of Oklahoma (Droegemeier, et. al.).

Part of the agreement between the NWS and the UPC allows for the
redistribution of all of the Level II data to interested universities,
but this distribution will need to be done by the UPC and cooperating
universities through the IDD.

Currently, the Level II volume scan data for between 55 to 61 NEXRADs
is available through the CRAFT IDD feed.  Time series plots of the
data volume for this feed can be seen in the CRAFT link located in the
real time statistics page for thelma.ucar.edu:


As you will see when you visit the above web page, the volume of data
currently peaks at around 140 MB per hour.  When the full complement of
NEXRAD Level II data is incorporated into the NWS stream (which we will
still refer to as CRAFT for IDD purposes), the total volume will climb
to at least two to four times what is currently available.  Moreover,
the data volume will likely increase by an additional factor of four to
eight in the future.  For comparison, the full CONDUIT IDD stream peaks
at between 1.8 and 2.0 GB per hour.

Since most of you have expressed an interest in the Level II data, and
since a number of you have indicated some level of interest in playing
an active role in relaying some or all of the data, we are soliciting
your help in establishing top level nodes for the NEXRAD Level II

Are you willing to help?  Please let us know!

Thanks in advance...

Tom Yoksas
**** < Unidata User Support                                    UCAR
Unidata Program < (303)497-8644
P.O. Box 3000 < address@hidden
---- < Unidata WWW Service

Mike Voss
Department of Meteorology
San Jose State University
One Washington Square
San Jose, CA 95192-0104

408.924.5204 voice
408.924.5191 fax

Linda Miller - address@hidden
External Liaison, Unidata
University Corporation for Atmospheric Research
P.O. Box 3000
Boulder, CO 80307-3000
303-497-8646 fax: 303-497-8690
URL:  http://www.unidata.ucar.edu/staff/lmiller/un.act.html