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

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 sites.


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
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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