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20020911: File counts (cont.)

>From: Kelvin Droegemeier <address@hidden>
>Organization: OU/CAPS
>Keywords: 200209101349.g8ADnQ118052 NEXRAD Level III volume scans

Kelvin,

>Thanks so much for taking time to explain this.  Since our last
>exchange, I've spoken with the folks at Unisys, who said, like you,
>that the many comm links involved in Level III transmission could
>result in volume scan losses from our satellite downlink.  A direct
>NOAAPort feed, like you and WSI have, will likely have higher file
>counts, which is what we've found in talking with WSI.

Sounds reasonable.

>I can't thank you enough for begin willing to generate the file count
>stats for us.

No worries.  The counts are now accessible through the web:

http://motherlode.ucar.edu/cgi-bin/ldm/genweb?raw/nexrad/nids_counts

Access to the files is password protected ('cause it is combined with
access to online data), so you will need to know the password to see
the numbers:  'lotzodata'.  Each day, the number days for which there
are counts will increase.  Since the sizes of the files are small
(around 3300 bytes), we will let this run for awhile with no scouring.

>Yours are going to be closer to ground truth than ours,
>though ours do in fact represent a valid comparison of a commercial
>Level III feed....so we have to couch our results in those terms,
>rather than using our Level III counts as proxies for what the radar
>actually collected.

Right.

>I'm attaching an Excel file that contains Level II and III stats for
>several radars for a few months.  We've updated the list, but my copy
>is a week or so old....  nevertheless, it'll give you some idea of the
>reliability of Level II versus III.

Linda printed out the Excel file.  I was under the impression that
you are getting Level II data from a lot more than 6 sites.  Is the
Excel list shortened, or am I wrong in the assumption of how many
Level II sites you are getting data from?

>Is there a way we can get the file
>counts from you in soft copy so that we can insert them into our
>matrix?

Is the web access sufficient?  Is the format of the data on the web
what you want?  If not, please let me know.

>If you like, I can call at your convenience to talk a bit more about
>CRAFT and to give you some of the bigger picture issues about the
>project and the importance of the information you're helping us
>collect.

Linda has filled us in on a lot of this.  The big picture is always
of interest, but I know that you are busy, so don't call if you don't
have the time.

>The file count ratios, or pseudo- reliability, is meant to
>show that the LDM-Internet-based Level II ingest methodology is quite
>stable, perhaps even as good as a commercial Level III feed

We believe this to be true.

>even though
>CRAFT is very much a research project and does not provide 7x24
>support, does not have sophisticated monitoring software, etc.

The IDD is a research project itself.  Like CRAFT, we do not provide
7x24 support for it either.

>Sooner Weather Girl is Lora Wilson, an undergraduate here at OU who is
>helping with the statistical analysis.

OK.  The CC was interesting enough for me to ask. :-)

>I have a digital picture of her
>but would need to run it through Photoshop before sending.....you know,
>not very flattering, etc.

Don't bother.  I was just curious about the interesting email address.

>Thanks Tom!!

No worries.  Perhaps this should shape Unidata's motto:

'Doing good stuff for our sites!' :-)

Tom