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[IDD #IJB-717945]: Questions about bufr format GPS data

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  • Subject: [IDD #IJB-717945]: Questions about bufr format GPS data
  • Date: Fri, 16 Jan 2009 10:08:05 -0700
Hi Elmer,

re: bufr-formatted GPS data

> Ok ... lets see if I can explain better.
> 
> We get buffer format GPS data from NOAAPORT.

Question:

- from a NOAAPort satellite reception system, or from an
  IDD feed that is populated by data from a NOAAPort satellite
  reception system

> The problem is that there seems to be a delay in getting the data, by
> delay I mean that the time on the file is (for example) 1315, the time
> it got to my system is 1550, and they are often out of sequence.  This
> is a list of the last 10 files we have received, in the order they were
> received:
> [ldm@gp75 ISXT40_]$ ls -ltr|tail -10
> -rw-r--r--  1 ldm ops 54592 Jan 16 15:19 KBOU_200901160715
> -rw-r--r--  1 ldm ops 32268 Jan 16 15:20 KBOU_200901161215
> -rw-r--r--  1 ldm ops  5752 Jan 16 15:49 KBOU_200901161515
> -rw-r--r--  1 ldm ops 39938 Jan 16 15:49 KBOU_200901160815
> -rw-r--r--  1 ldm ops 55538 Jan 16 15:49 KBOU_200901160745
> -rw-r--r--  1 ldm ops 34088 Jan 16 15:50 KBOU_200901161245
> -rw-r--r--  1 ldm ops 31780 Jan 16 15:50 KBOU_200901161315
> -rw-r--r--  1 ldm ops 34382 Jan 16 15:50 KBOU_200901161345
> -rw-r--r--  1 ldm ops 22324 Jan 16 15:50 KBOU_200901161415
> -rw-r--r--  1 ldm ops 14492 Jan 16 15:50 KBOU_200901161445
> 
> 
> This has been updating at xx20 and xx50 since the day we set it up.  Our
> customer used to get GPS data from FSL where the data was there every I
> think they said 15 mins, so they are asking why the delay.

Comments:

- if the data is coming from a NOAAPort satellite ingest system, then
  the delay is on NOAA's side

- if the delay is in an IDD feed that was populated by a NOAAPort satellite
  ingest system, then the delay could be on NOAA's side OR it could be
  in some delay in the machine(s) relaying the data via the IDD.

The best way to ascertain where the delay is coming from for IDD feeds is
to use the LDM utility 'notifyme'.  Run 'notifyme' on your system specifying
a pattern that matches the products you are investigating -- leave 'notifyme'
running. 'notifyme -vxl -f ...' will show the receipt of the product, AND the
time that the product was originally injected into the IDD.  If the difference
in time of receipt on your system and the time of injection into the IDD
is small, the delay in the delivery of the products is in when they were
broadcast by NOAA.  If the difference in these times is high, then the
problem is somewhere in the relay of the data to your machine.

Cheers,

Tom
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Ticket Details
===================
Ticket ID: IJB-717945
Department: Support IDD
Priority: Normal
Status: Closed