[ldm-users] 20080216: NNEXRAD Level 3

• To: "Jeffrey Lake - Admin" <admin@xxxxxxxxxxxxxxxxxxxx>
• Subject: [ldm-users] 20080216: NNEXRAD Level 3
• From: Tom Yoksas <yoksas@xxxxxxxxxxxxxxxx>
• Date: Sat, 16 Feb 2008 10:56:02 -0700

Hi Jeff,

re:
>Is anybody else seeing extremely wierd happenings with the
>LDM NNEXRAD Data ?

No.

>For the last 3 hours I have seen almost 3/4 of the sites just stop flowing
>and then as fast as they stop they are back.

The NNEXRAD (Nexrad Level 3) latencies for your machine do not indicate
any systematic problem with the flow of the data in the IDD:

http://www.unidata.ucar.edu/cgi-bin/rtstats/iddstats_nc?NNEXRAD+level3.michiganwxsystem.net

Are your observations on "wierd happenings"  based on receipt of the
Level 3 products in your LDM queue or their availability on your disk
after being processed out of your queue?  If the answer is the latter,
then your system may be bound up somehow (e.g., disk I/O, etc.).  If
the answer is the former, then I suspect that the burstiness is
related to the NOAAPort broadcast, not the IDD delivery of the
products.

>When I look at the NWS's Radar status page they have nothing noted there..

We are not seeing anything unusual with the IDD here at Unidata, but,
then again, we are not looking at the data as closely as you.

By the way, the log(latency) plot for your machine shows that you are
likely running ntpdate to set your system clock once per day:

http://www.unidata.ucar.edu/cgi-bin/rtstats/iddstats_nc?NNEXRAD+level3.michiganwxsystem.net+LOG

We recommend that you switch to use of ntpd so that your clock does not
drift so much.

Cheers,

Tom
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* Tom Yoksas                                            UCAR Unidata Program *
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* yoksas@xxxxxxxxxxxxxxxx                                  Boulder, CO 80307 *
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• References:
  • [ldm-users] NNEXRAD Level 3
    • From: Jeffrey Lake - Admin